Bell 412 Component Repair Manual

BHT-412-CRO
COMPONENT REPAIR AND OVERHAUL MANUAL
NOTICE
The instructions set forth in this manual, as supplemented or modified by Alert Service Bulletins (ASB)
or other directions issued by Bell and Airworthiness Directives (AD) issued by the applicable regulatory
agencies, shall be strictly followed.
Copyright © 2023 Bell Helicopter Textron Inc. and Bell Helicopter Textron
Canada Ltd. All rights reserved
Export Classification C, ECCN EAR99
Issue 003 - 28 OCT 2024
BHT-412-CRO
PROPRIETARY RIGHTS NOTICE
These data are proprietary to Bell Disclosure, reproduction, or use of these data
for any purposes other than helicopter operation and maintenance is forbidden
without prior authorization from Bell
DESTINATION CONTROL STATEMENT
These commodities, technology, or software were exported from the United
States in accordance with the Export Administration Regulations (EAR).
Diversion contrary to U.S. law prohibited.
Additional copies of this publication may be obtained by contacting:
Commercial Publications Distribution Center Bell P.O. Box 482 Fort
Worth, Texas 76101-0482
412-A-00-75-00-00A-001A-A
Page II 28 OCT 2024
Applicable to: ALL
ECCN EAR99
BHT-412-CRO
Highlights
The listed changes are introduced in issue 003, dated 2024-10-28, of this publication.
C = Changed data module, N = New data module
Data module
Reason for update
412-A-62-20-00-02A-353A-B / 00069, Main Rotor Hub
and Sleeve Assembly (412-010-401-105, -107, -109,
-111, -113, -115, and -117) - Non-destructive Inspection
Updated the table 1 title from ‘mast assembly’ to ‘main
rotor hub and sleeve assembly’.
N/C
Chapter 62 - Main Rotor:
C
Chapter 63 - Main Rotor Drive:
C
412-A-63-10-00-00A-530A-B / 00099, Main Driveshaft
(212-040-005-103) - Disassembly
Modified the note applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
C
412-A-63-10-00-00A-258A-B / 00100, Main Driveshaft
(212-040-005-103) - Cleaning
Modified the note applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
C
412-A-63-10-00-00A-280A-B / 00101, Main Driveshaft
(212-040-005-103) - Inspection
Modified the note applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
C
412-A-63-10-00-00A-284A-B / 00102, Main Driveshaft
(212-040-005-103) - Conditional Inspection
Modified the note applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
C
412-A-63-10-00-00A-280B-B / 00103, Main Driveshaft
(212-040-005-103) - Normal Inspection
Modified the note applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
C
412-A-63-10-00-00A-685A-B / 00104, Main Driveshaft
(212-040-005-103) - Repair
Modified the note applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
C
412-A-63-10-00-00A-240A-B / 00105, Main Driveshaft
(212-040-005-103) - Lubrication
Modified the note applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
C
412-A-63-10-00-00A-710A-B / 00106, Main Driveshaft
(212-040-005-103) - Assembly
Modified the note applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
C
412-A-63-10-00-02A-530A-B / 00107, Main Driveshaft
(412-040-005-101 and -103) - Disassembly
Modified the applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
Updated DMC title to add part number 412-040-005-101
and -103.
C
412-A-63-10-00-02A-258A-B / 00108, Main Driveshaft
(412-040-005-101 and -103) - Cleaning
Modified the applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
Updated DMC title to add the part number
412-040-005-101 and -103.
C
412-A-63-10-00-02A-280A-B / 00109, Main Driveshaft
(412-040-005-101 and -103) - Inspection
Modified the applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
Updated DMC title to add the part number
412-040-005-101 and -103.
C
412-A-63-10-00-02A-284A-B / 00110, Main Driveshaft
(412-040-005-101 and -103) - Conditional Inspection
Modified the applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
Updated DMC title to add the part number
412-040-005-101 and -103.
C
412-A-63-10-00-02A-280B-B / 00111, Main Driveshaft
(412-040-005-101 and -103) - Normal Inspection
Modified the applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
Updated DMC title to add the part number
412-040-005-101 and -103.
C
412-A-63-10-00-02A-685A-B / 00112, Main Driveshaft
(412-040-005-101 and -103) - Repair
Modified the applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
Updated DMC title to add the part number
412-040-005-101 and -103.
C
412-A-63-10-00-02A-240A-B / 00113, Main Driveshaft
(412-040-005-101 and -103) - Lubrication
Modified the applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
Updated DMC title to add the part number
412-040-005-101 and -103.
Applicable to: ALL
ECCN EAR99
412-A-00-00-00-00A-00UA-A
28 OCT 2024 Page III
BHT-412-CRO
N/C
Data module
Reason for update
C
412-A-63-10-00-02A-710A-B / 00114, Main Driveshaft
(412-040-005-101 and -103) - Assembly
Modified the applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
Updated DMC title to add the part number
412-040-005-101 and -103.
C
412-A-63-10-00-05A-530A-B / 00121, Transmission
Main Rotor Mast Assemblies (412-040-366-109 and
Subsequent) - Disassembly
Revised the sheet 1 of figure 1 to add the torque symbol
for callout 10 and 23, changed the location of Detail C
from the callout 35 to 23.
C
412-A-63-10-00-05A-258A-B / 00122, Transmission
Main Rotor Mast Assemblies (412-040-366-109 and
Subsequent) - Cleaning
Revised the Sheet 1 of Figure 1 to add the torque
symbol for callout 10 and 23, changed the location of
Detail C from the callout 35 to 23.
C
412-A-63-10-00-05A-280A-B / 00123, Transmission
Main Rotor Mast Assemblies (412-040-366-109 and
Subsequent) - Inspection
Revised the sheet 1 of figure 2 to add the torque symbol
for callout 10 and 23 changed the location of Detail C
from the callout 35 to 23.
C
412-A-63-10-00-05A-710A-B / 00125, Transmission
Main Rotor Mast Assemblies (412-040-366-109 and
Subsequent) - Assembly
Updated wrench assembly identification number from
412-240-031-101 to 412-240-003-101 in support
equipment.
Revised the sheet 1 of figure 1 to add the torque symbol
for callout 10 and 23, changed the location of Detail C
from the callout 35 to 23.
C
412-A-63-10-00-06A-530A-B / 00127, Transmission Disassembly
Grammatical changes to step 51.4.
Modified the figure 14 to change the item number of
packing from 1 to 2.
C
412-A-63-10-00-06A-710A-B / 00133, Transmission
- Assembly
Revised step 60 from ‘Coat the threads of the elbow
(17 and 8, Figure 17) (18 and 7) with the same oil used
in the transmission’.
Added sheet 2 for figure 15.
Modified the figure 3 to change the item number of
packing from 1 to 2.
C
412-A-63-10-00-10A-530A-B / 00147, Transmission
Modified sheet 3 of figure 1 to show proper clarity view
Main Support Case (212-040-054-013, -101, -105, -109 of View D.
and -117) - Disassembly
C
412-A-63-10-00-10A-258A-B / 00148, Transmission
Modified sheet 3 of figure 1 to show proper clarity view
Main Support Case (212-040-054-013, -101, -105, -109 of View D.
and -117) - Cleaning
C
412-A-63-10-00-10A-280A-B / 00149, Transmission
Modified sheet 3 of figure 1 to show proper clarity view
Main Support Case (212-040-054-013, -101, -105, -109 of View D.
and -117) - Inspection
C
412-A-63-10-00-10A-685A-B / 00150, Transmission
Added Cadmimum plating solution (C-108) in
Main Support Case (212-040-054-013, -101, -105, -109 consumables table.
and -117) - Repair
Modified the procedural step 6 and 7 to add cadmium
plating solution (C-108).
Modified sheet 3 of figure 1 to show proper clarity view
of View D.
C
412-A-63-10-00-10A-710A-B / 00151, Transmission
Modified sheet 3 of figure 1 to show proper clarity view
Main Support Case (212-040-054-013, -101, -105, -109 of View D.
and -117) - Assembly
C
412-A-63-10-00-12A-530A-B / 00158, Upper Planetary
Assembly (204-040-360-005, -103, -105 And
412-040-360-101) - Disassembly
Revised the DMC title to add part number
412-040-360-101.
Revised the sheet 3 of figure 1 to delete the part number
for thrust washer 204-040-134-005.
C
412-A-63-10-00-12A-258A-B / 00159, Upper Planetary
Assembly (204-040-360-005, -103, -105 and
412-040-360-101) - Cleaning
Revised the DMC title to add part number
412-040-360-101.
412-A-00-00-00-00A-00UA-A
Page IV 28 OCT 2024
Applicable to: ALL
ECCN EAR99
BHT-412-CRO
N/C
Data module
Reason for update
C
412-A-63-10-00-12A-280A-B / 00160, Upper Planetary
Assembly (204-040-360-005, -103, -105 And
412-040-360-101) - Inspection
Revised the DMC title and table 1 title to add part
number 412-040-360-101.
Updated part number of bearing inner race from
"204-040-132-101" to "204-040-132-001" and added
part number 412-340-132-101 in table 1.
Updated part number of pinion gear from
"205-040-233-105 to 205-040-233-001" and added part
number 412-040-234-101 in table 1.
Modified procedural step 5 to delete the part numbers
204-040-129-001 and 205-340-001-101.
Modified figure 1 to add part number 204-040-360-005/103 and 412-040-360-101.
Modified the sheet 3 of figure 2 to delete the part
numbers for thrust washer 204-040-134-005.
Modified figure 4 to add part number 412-040-133-101.
C
412-A-63-10-00-12A-685A-B / 00161, Upper Planetary
Assembly (204-040-360-005, -103, -105 And
412-040-360-101) - Repair
Revised procedural step 2 to change the DMC
reference from "DMC-412-A-63-10-00-12A-530A-B" to
"DMC-412-A-63-10-00-12A-280A-B" .
Revised the DMC title to add part number
412-040-360-101.
Revised sheet 3 of figure 1 to delete thrust washer part
number 204-040-134-005.
C
412-A-63-10-00-12A-710A-B / 00162, Upper Planetary
Assembly (204-040-360-005, -103, -105 And
412-040-360-101) - Assembly
Revised the DMC title to add the part number
412-040-360-101.
Revised sheet 3 of figure 1 to delete thrust washer part
number 204-040-134-005.
C
412-A-63-10-00-13A-710A-B / 00167, Lower Planetary
Assembly - Assembly
Modified the procedural steps 14 & 18 to add the part
number 204-240-009-001.
C
412-A-63-10-00-14A-530A-B / 00168, Main Input Gear
Quill (204-040-362-103) - Disassembly
Modified the note applicability to add serial
number(37002-37999) and (38001-38999 and
39101-39999).
C
412-A-63-10-00-14A-258A-B / 00169, Main Input Gear
Quill (204-040-362-103) - Cleaning
Modified the note applicability to add serial
number(37002-37999) and (38001-38999 and
39101-39999).
C
412-A-63-10-00-14A-280A-B / 00170, Main Input Gear
Quill (204-040-362-103) - Inspection
Modified the note applicability to add serial
number(37002-37999) and (38001-38999 and
39101-39999).
C
412-A-63-10-00-14A-685A-B / 00171, Main Input Gear
Quill (204-040-362-103) - Repair
Modified the note applicability to add serial
number(37002-37999) and (38001-38999 and
39101-39999).
C
412-A-63-10-00-14A-710A-B / 00172, Main Input Gear
Quill (204-040-362-103) - Assembly
Modified the note applicability to add serial
number(37002-37999) and (38001-38999 and
39101-39999).
C
412-A-63-10-00-15A-530A-B / 00173, Main Input Gear
Quill (412-040-362-101, -103 and -105) - Disassembly
Revised the DMC title to add part number
412-040-362-105.
Changes to figure 1: Added part number
412-040-362-105 to note 1 and updated figure title to
add part number 412-040-362-103 and -105.
Modified the applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
Modified the note above step 5 to add part number
412-040-362-105.
C
412-A-63-10-00-15A-258A-B / 00174, Main Input Gear
Quill (412-040-362-101, -103 and -105) - Cleaning
Revised the DMC title to add part number
412-040-362-105.
Modified the applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
Applicable to: ALL
ECCN EAR99
412-A-00-00-00-00A-00UA-A
28 OCT 2024 Page V
BHT-412-CRO
N/C
Data module
Reason for update
C
412-A-63-10-00-15A-280A-B / 00175, Main Input Gear
Quill (412-040-362-101, -103 and -105) - Inspection
Revised the DMC title to add part number
412-040-362-105.
Changes to figure 1: Added part number
412-040-362-105 to note 1 and updated figure title to
add part number 412-040-362-103 and -105.
Modified the applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
Added part number 412-040-701-107 for Gear Assembly
in Table 1 and figure 3 title.
Grammatical correction to steps 8, 8.4, 8.6, 9.2, 9.2.1,
9.2.2, 9.2.3, 9.2.7 and 9.2.10.
Modified figure 5 to change the maximum inner diameter
damage limit of bearings from (199.9794) to (119.9794).
C
412-A-63-10-00-15A-685A-B / 00176, Main Input Gear
Quill (412-040-362-101, -103 and -105) - Repair
Revised the DMC title to add part number
412-040-362-105.
Modified the applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
Modified figure 1 to change the maximum inner diameter
damage limit of bearings from (199.9794) to (119.9794).
C
412-A-63-10-00-15A-710A-B / 00177, Main Input Gear
Quill (412-040-362-101, -103 and -105) - Assembly
Revised the DMC title and procedural step 8 to add part
number 412-040-362-105.
Changes to figure 1: Added part number
412-040-362-105 to note 1 and updated figure title to
add part number 412-040-362-103 and -105.
Grammatical changes to step 2, 3, 4.1, 4.3, 7, 9 and 11.
Revised the table of step 4.1 and table VI of step 4.3 to
change the dimension from (K or L) to (L).
Modified the applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
Modified figure 2 title to add part number
412-040-362-103 and 105.
C
412-A-63-10-00-16A-530A-B / 00178, Main Input Quill
(212-040-263-107) - Disassembly
Modified the note applicability to add serial
number(37002-37999) and (38001-38999 and
39101-39999).
C
412-A-63-10-00-16A-258A-B / 00179, Main Input Quill
(212-040-263-107) - Cleaning
Modified the note applicability to add serial
number(37002-37999) and (38001-38999 and
39101-39999).
C
412-A-63-10-00-16A-280A-B / 00180, Main Input Quill
(212-040-263-107) - Inspection
Revised the part number of pinion from
"204-040-700-001" to 204-040-700-101 in table
1.
Modified the note applicability to add serial
number(37002-37999) and (38001-38999 and
39101-39999).
C
412-A-63-10-00-16A-685A-B / 00181, Main Input Quill
(212-040-263-107) - Repair
Modified the note applicability to add serial
number(37002-37999) and (38001-38999 and
39101-39999).
C
412-A-63-10-00-16A-710A-B / 00182, Main Input Quill
(212-040-263-107) - Assembly
Modified the note applicability to add serial
number(37002-37999) and (38001-38999 and
39101-39999).
C
412-A-63-10-00-17A-530A-B / 00183, Main Input Quill
(212-040-263-101) - Disassembly
Added arrow to show the seal lip direction in figure 1.
C
412-A-63-10-00-17A-280A-B / 00185, Main Input Quill
(212-040-263-101) - Inspection
Added arrow to show the seal lip direction in figure 1.
C
412-A-63-10-00-17A-685A-B / 00186, Main Input Quill
(212-040-263-101) - Repair
Added arrow to show the seal lip direction in figure 1.
C
412-A-63-10-00-17A-710A-B / 00187, Main Input Quill
(212-040-263-101) - Assembly
Added arrow to show the seal lip direction in figure 1.
412-A-00-00-00-00A-00UA-A
Page VI 28 OCT 2024
Applicable to: ALL
ECCN EAR99
BHT-412-CRO
N/C
Data module
Reason for update
C
412-A-63-10-00-18A-530A-B / 00188, Main Input Quill
(412-040-263-ALL) - Disassembly
Revised the Figure 1 title to add part number
412-040-263-103.
Modified the applicability to add serial number
"(37002-37999) and (38001-38999 and 39101-39999).
C
412-A-63-10-00-18A-258A-B / 00189, Main Input Quill
(412-040-263-ALL) - Cleaning
Modified the applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
C
412-A-63-10-00-18A-280A-B / 00190, Main Input Quill
(412-040-263-ALL) - Inspection
Modified the applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
Revised the figure 1 title to add part number
412-040-263-103.
Revised the Table 1 and sheet 1 of Figure 2 to add the
pinion part number 412-040-700-103 and -105.
Revised the Figure 6 title to add part number
412-040-136-103.
Revised the Figure 8 and 9 title to add part number
412-040-111-107.
C
412-A-63-10-00-18A-685A-B / 00191, Main Input Quill
(412-040-263-ALL) - Repair
Modified the applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
Modified sheet 1 of Figure 2 to add the pinion part
number 412-040-700-103 and -105.
Updated the Figure 1 to add part number
412-040-263-103.
C
412-A-63-10-00-18A-710A-B / 00192, Main Input Quill
(412-040-263-ALL) - Assembly
Modified the applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
Updated the figure 1 title to add part number
412-040-263-103.
C
412-A-63-10-00-24A-530A-B / 00219, Full Flow Debris
Monitor (212-040-122-101 and -103) - Disassembly
Modified procedural step 1 from "Remove the debris
scavenge cup/screen tube assembly (2, Figure 1),
scupper (1), filter element (3), and packing (4). Discard
the packing (4).".
C
412-A-63-10-00-24A-710A-B / 00223, Full Flow Debris
Monitor (212-040-122-101 and -103) - Assembly
Deleted procedural step 2 and 3.
Modified the procedural step 4 from "Install the debris
scavenge cup/screen tube assembly (2) to attach the
filter element (3) and the scupper (1). Torque the
debris scavenge cup/screen tube assembly (2) 22 to 30
inch-pounds (2.48 to 3.39 Nm).".
C
412-A-63-10-00-25A-280A-B / 00226, Accessory and
Tail Rotor Drive Quill (212-040-365-023 and -115) Inspection
Deleted the part number 212-040-197-001 and its
associated data from table 1.
Changes to part number 212-040-150-005 in table
1: Changed from "Current for primary diameters,
magnetize at 1030 amps." to "Current for primary
diameters, magnetize at 2550 amps" and added new
step.
Modified table 1 title to add part number
212-040-365-115.
C
412-A-63-10-00-26A-530A-B / 00229, Tail Rotor Drive
Quill (212-040-365-025) - Disassembly
Modified the note applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
C
412-A-63-10-00-26A-258A-B / 00230, Tail Rotor Drive
Quill (212-040-365-025) - Cleaning
Modified the note applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
C
412-A-63-10-00-26A-280A-B / 00231, Tail Rotor Drive
Quill (212-040-365-025) - Inspection
Modified the note applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
C
412-A-63-10-00-26A-685A-B / 00232, Tail Rotor Drive
Quill (212-040-365-025) - Repair
Updated conversion value from 12.7 mm to 1.27 mm
under procedural step 4.2.
Modified the note applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
C
412-A-63-10-00-26A-710A-B / 00233, Tail Rotor Drive
Quill (212-040-365-025) - Assembly
Modified the note applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
Applicable to: ALL
ECCN EAR99
412-A-00-00-00-00A-00UA-A
28 OCT 2024 Page VII
BHT-412-CRO
N/C
Data module
Reason for update
C
412-A-63-10-00-27A-530A-B / 00234, Tail Rotor Drive
Quill (212-040-365-113 AND -135) - Disassembly
Revised the DMC title and Figure 1 title to add part
numbers 212-040-365-113 and -135.
Revised the applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
C
412-A-63-10-00-27A-258A-B / 00235, Tail Rotor Drive
Quill (212-040-365-113 AND -135) - Cleaning
Revised the DMC title to add part numbers
212-040-365-113 and -135.
Modified the applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
C
412-A-63-10-00-27A-280A-B / 00236, Tail Rotor Drive
Quill (212-040-365-113 AND -135) - Inspection
Updated the DMC title to add part numbers
212-040-365-113 and -135.
Added the part number 212-040-365-135 for Tail Rotor
Drive Quill Assembly in table 1.
Added part number 412-040-151-101 for Gear in table 1.
Updated the figure 1 title to add part number
212-040-365-135.
Updated the figure 2 title to add part number
212-040-365-113 and -135.
Modified the applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
C
412-A-63-10-00-27A-685A-B / 00237, Tail Rotor Drive
Quill (212-040-3645-113 AND -135) - Repair
Updated the DMC title and figure 1 title to add part
numbers 212-040-365-113 and -135.
Modified the applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
C
412-A-63-10-00-27A-710A-B / 00238, Tail Rotor Drive
Quill (212-040-365-113 AND -135) - Assembly
Updated the DMC title and figure 1 title to add part
numbers 212-040-365-113 and -135.
Modified the applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
C
412-A-63-10-00-28A-280A-B / 00241, Single Boost (or
System 1) Hydraulic Drive Quill (212-040-365-103) Inspection
Revised the part number of sprocket from
"212-040-112-001" to "204-040-112-001" in table 1.
Revised the part number of gear from "204-040-149-101"
to "212-040-149-001" in table 1.
C
412-A-63-10-00-29A-280A-B / 00246, Rotor Brake Drive Modified the figure 3 to change the position of the arrow
Quill (412-040-123-101 and -103) - Inspection
(0.5 IN. (12.7 mm) DIA TO DEPTH SHOW) to the inner
diameter.
Chapter 65 - Tail Rotor Drive:
C
412-A-65-10-00-00A-530A-B / 00277, Tail Rotor
Driveshaft Hanger Assembly (212-040-600-005/-101) Disassembly
Modified the note applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
C
412-A-65-10-00-00A-258A-B / 00278, Tail Rotor
Driveshaft Hanger Assembly (212-040-600-005/-101) Cleaning
Modified the note applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
C
412-A-65-10-00-00A-280A-B / 00279, Tail Rotor
Driveshaft Hanger Assembly (212-040-600-005/-101)
- Inspection
Modified the note applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
C
412-A-65-10-00-00A-284A-B / 00280, Tail Rotor
Driveshaft Hanger Assembly (212-040-600-005/-101) Conditional Inspection
Modified the note applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
C
412-A-65-10-00-00A-280B-B / 00281, Tail Rotor
Driveshaft Hanger Assembly (212-040-600-005/-101)
- Normal Inspection
Modified the note applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
Deleted figure 3 to figure 13.
C
412-A-65-10-00-00A-685A-B / 00282, Tail Rotor
Driveshaft Hanger Assembly (212-040-600-005/-101)
- Repair
Modified the note applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
C
412-A-65-10-00-00A-710A-B / 00283, Tail Rotor
Driveshaft Hanger Assembly (212-040-600-005/-101)
- Assembly
Modified the note applicability to add serial number
(37002-37999) and (38001-38999 and 39101-39999).
412-A-00-00-00-00A-00UA-A
Page VIII 28 OCT 2024
Applicable to: ALL
ECCN EAR99
BHT-412-CRO
Data module
N/C
Reason for update
C
412-A-65-10-00-02A-530A-B / 00284, Tail Rotor
Modified the applicability to add serial number
Driveshaft Hanger Assembly (412-040-600-101/ -103) - (38001-38999 and 39101-39999).
Disassembly
Grammatical changes to Step 2, 4 and 5.
C
412-A-65-10-00-02A-258A-B / 00285, Tail Rotor
Modified the applicability to add serial number
Driveshaft Hanger Assembly (412-040-600-101/ -103) - (38001-38999 and 39101-39999).
Cleaning
Grammatical changes to step 1 and 2.
C
412-A-65-10-00-02A-280A-B / 00286, Tail Rotor
Driveshaft Hanger Assembly (412-040-600-101/ -103)
- Inspection
C
412-A-65-10-00-02A-284A-B / 00287, Tail Rotor
Modified the applicability to add serial number
Driveshaft Hanger Assembly (412-040-600-101/ -103) - (38001-38999 and 39101-39999).
Conditional Inspection
C
412-A-65-10-00-02A-280B-B / 00288, Tail Rotor
Driveshaft Hanger Assembly (412-040-600-101/ -103)
- Normal Inspection
Modified the applicability to add serial number
(38001-38999 and 39101-39999).
C
412-A-65-10-00-02A-685A-B / 00289, Tail Rotor
Driveshaft Hanger Assembly (412-040-600-101/ -103)
- Repair
Modified the applicability to add serial number
(38001-38999 and 39101-39999).
C
412-A-65-10-00-02A-710A-B / 00290, Tail Rotor
Driveshaft Hanger Assembly (412-040-600-101/ -103)
- Assembly
Modified the applicability to add serial number
(38001-38999 and 39101-39999).
Grammatical changes to the step 1, 2 and 3.
Updated the caution above step 1 and note above the
step 4 to update the reference for 412-IPB, Chapter 65.
C
412-A-65-10-00-04A-530A-B / 00291, Tail Rotor
Driveshaft Coupling Assembly (412-040-601-105/
-107/-111) - Disassembly
Modified the applicability to add serial number
(38001-38999 and 39101-39999).
Grammatical changes to steps 3, 5, 6 and 7
C
412-A-65-10-00-04A-258A-B / 00292, Tail Rotor
Driveshaft Coupling Assembly (412-040-601-105/
-107/-111) - Cleaning
Modified the applicability to add serial number
(38001-38999 and 39101-39999).
Grammatical changes to step 1.
C
412-A-65-10-00-04A-280A-B / 00293, Tail Rotor
Driveshaft Coupling Assembly (412-040-601-105/
-107/-111) - Inspection
Modified the applicability to add serial number
(38001-38999 and 39101-39999).
Updated step 1 from 'Refer to the (412-MM, Chapter 5)
for the definition of accidents, or incidents, that require
the conditional inspection be conducted'.
C
412-A-65-10-00-04A-284A-B / 00294, Tail Rotor
Driveshaft Coupling Assembly (412-040-601-105/
-107/-111) - Conditional Inspection
Modified the applicability to add serial number
(38001-38999 and 39101-39999).
C
412-A-65-10-00-04A-280B-B / 00295, Tail Rotor
Driveshaft Coupling Assembly (412-040-601-105/
-107/-111) - Normal Inspection
Deleted Figure 4 and 5.
Modified coupling assembly part number to add
412-040-601-107 and -111 in table 1.
Removed figure 4 and 5 reference from table 1.
Deleted part number 412-040-627-101 from table 1.
Modified sheet 1 of figure 2 to add part number
412-040-601-111.
Modified the applicability to add serial number
(38001-38999 and 39101-39999).
C
412-A-65-10-00-04A-685A-B / 00296, Tail Rotor
Driveshaft Coupling Assembly (412-040-601-105/
-107/-111) - Repair
Modified the applicability to add serial number
(38001-38999 and 39101-39999).
Grammatical Changes to step 5, 7.2 and 7.3.
C
412-A-65-10-00-04A-710A-B / 00297, Tail Rotor
Driveshaft Coupling Assembly (412-040-601-105/
-107/-111) - Assembly
Modified the applicability to add serial number
(38001-38999 and 39101-39999).
Updated the caution above the step 1 and note above
step 9 to update reference for 412-IPB, Chapter 65.
Grammatical changes to Step 1,2 and 3.
Applicable to: ALL
ECCN EAR99
Modified the applicability to add serial number
(38001-38999 and 39101-39999).
Updated the procedural step 1 from 'Refer to the
BHT-412-MM, Chapter 5 for the definition of accidents,
or incidents, that require the conditional inspection be
conducted'.
412-A-00-00-00-00A-00UA-A
28 OCT 2024 Page IX
BHT-412-CRO
N/C
Data module
Reason for update
C
412-A-65-10-00-06A-280B-B / 00302, Tail Rotor
Driveshaft Coupling Assembly (412-040-601-101/-109)
- Normal Inspection
Deleted part number 212-040-604-103 for outer coupling
in table 1.
Deleted part number 412-040-631-101 and the
associated inspection data from table 1.
Grammatical changes to step 9.
C
412-A-65-20-00-00A-685A-B / 00311, Intermediate
Gearbox - Repair
Modified the procedural step 3 from "Replace
unserviceable oil filler cap adapter (24, Figure 2) when
damaged. Install new adapter coated with Epoxy
polyamide primer (C-204)." to "Replace unserviceable
oil filler cap adapter (24, Figure 2) when damaged as
follows:".
Added new sub procedural step from "3.1 to 3.7".
Grammatical changes to step 5.
C
412-A-65-20-00-08A-280B-B / 00340, Intermediate
Gearbox Output Quill (412-040-006-105 and -115) Normal Inspection
Modified the procedural step 6 to update the SI value
from "7.62 mm" to ".7620 mm".
C
412-A-65-20-00-10A-685A-B / 00348, Tail Rotor
Gearbox - Repair
Added caution under step 12.3.
Updated step 12.4 to replace Nital Etch Inspection with
Magnetic Particle Inspection.
Modified procedural step 11 to add DMC-412-A-65-2001-02A-685A-A reference.
Deleted procedural step 11.1,11.2,11.3,11.4,11.5.
Added procedural step 13.
C
412-A-65-20-00-10A-257A-B / 00350, Tail Rotor
Gearbox - Painting
Updated the sheet 1 of figure 2 to add the sealant
symbol to the item number 13.
C
412-A-65-20-00-12A-530A-B / 00352, Tail Rotor
Gearbox Input Quill (212-040-004-011) - Disassembly
Updated the sheet 1 of figure 2 to add the sealant
symbol to the item number 13.
Revised note to add serial number 38001 through 38999
and 39101 through 39999.
C
412-A-65-20-00-12A-258A-B / 00353, Tail Rotor
Gearbox Input Quill (212-040-004-011) - Cleaning
Revised note to add serial number 38001 through 38999
and 39101 through 39999.
C
412-A-65-20-00-12A-280A-B / 00354, Tail Rotor
Gearbox Input Quill (212-040-004-011) - Inspection
Updated the sheet 1 of figure 2 to add the sealant
symbol to the item number 13.
Replaced the figure 2 to with new graphic.
Revised note to add serial number 38001 through 38999
and 39101 through 39999.
C
412-A-65-20-00-12A-685A-B / 00355, Tail Rotor
Gearbox Input Quill (212-040-004-011) - Repair
Updated the sheet 1 of figure 2 to add the sealant
symbol to the item number 13.
Revised note to add serial number 38001 through 38999
and 39101 through 39999.
C
412-A-65-20-00-12A-710A-B / 00356, Tail Rotor
Gearbox Input Quill (212-040-004-011) - Assembly
Updated the sheet 1 of figure 1 to add the sealant
symbol to the item number 13.
Replaced the figure 2 to with new graphic.
Revised note to add serial number 38001 through 38999
and 39101 through 39999.
Added steps 10 and 12.
Grammatical changes to step 11.
C
412-A-65-20-00-12A-257A-B / 00357, Tail Rotor
Gearbox Input Quill (212-040-004-011) - Painting
Updated the sheet 1 of figure 2 to add sealant symbol to
the item number 13.
Revised note to add serial number 38001 through 38999
and 39101 through 39999.
Chapter 67 - Flight Controls:
C
412-A-67-10-00-11A-280A-B / 00393, Cyclic Control
Tubes - Inspection
412-A-00-00-00-00A-00UA-A
Page X 28 OCT 2024
Changes to sheet 2 of figure 1: Added tube part number
212-076-151-007 and 212-076-151-011 in place of
212-001-151-101 and modified the last sentence of
flag note 2 in sheet 2 of figure 1 to update ‘collective’
to ‘cyclic’.
Applicable to: ALL
ECCN EAR99
BHT-412-CRO
Data module
N/C
Reason for update
C
412-A-67-10-00-11A-685A-B / 00394, Cyclic Control
Tubes - Repair
Changes to sheet 2 of figure 1: Added tube part number
212-076-151-007 and 212-076-151-011 in place of
212-001-151-101 and modified the last sentence of
flag note 2 in sheet 2 of figure 1 to update ‘collective’
to ‘cyclic’.
C
412-A-67-20-00-02A-685A-B / 00400, Anti-Torque
control Components - Repair
Modified procedural step 7 to add BHT-ALL-SPM
standard practice manual.
Deleted procedural steps From 7.1 to 9.23.
Chapter 71 - Power Plant:
C
412-A-71-20-00-00A-280A-B / 00416, Mounts and
Fittings - Inspection
Applicable to: ALL
ECCN EAR99
Revised the figure 11 to change the dimension of the top
holes from 0.279 to 0.255 IN." to "0.249 to 0.255 IN.
412-A-00-00-00-00A-00UA-A
28 OCT 2024 Page XI
BHT-412-CRO
Intentionally blank page
412-A-00-00-00-00A-00UA-A
Page XII 28 OCT 2024
Applicable to: ALL
ECCN EAR99
BHT-412-CRO
LIST OF CHAPTERS
Chapter
Chapter 01 - General Information
Chapter 28 - Fuel System
Chapter 29 - Hydraulic System
Chapter 32 - Landing Gear
Chapter 62 - Main Rotor
Chapter 63 - Main Rotor Drive
Chapter 64 - Tail Rotor
Chapter 65 - Tail Rotor Drive
Chapter 67 - Flight Controls
Chapter 71 - Power Plant
Chapter 79 - Engine Oil
Applicable to: ALL
ECCN EAR99
Data module code
412-A-01-00-00-00A-009A-A / 00006
412-A-28-00-00-00A-009A-A / 00008
412-A-29-00-00-00A-009A-A / 00013
412-A-32-00-00-00A-009A-A / 00030
412-A-62-00-00-00A-009A-A / 00048
412-A-63-00-00-00A-009A-A / 00098
412-A-64-00-00-00A-009A-A / 00258
412-A-65-00-00-00A-009A-A / 00276
412-A-67-00-00-00A-009A-A / 00364
412-A-71-00-00-00A-009A-A / 00414
412-A-79-00-00-00A-009A-A / 00418
412-A-00-00-00-00A-009A-A
28 OCT 2024 Page 00001-XIII
BHT-412-CRO
Intentionally blank page
412-A-00-00-00-00A-009A-A
Page 00001-XIV 28 OCT 2024
Applicable to: ALL
ECCN EAR99
BHT-412-CRO
List of Effective Data Modules
The listed documents are included in issue 003, dated 2024-10-28, of this publication.
C = Changed data module, N = New data module
Document title
Data module code / Seq number
Issue date
Applicable
to
Bulletin Record - Technical standard records
DMC-412-A-00-71-00-00A-008B-B /
00001.1
2023-11-14
ALL
Temporary revision record - Technical standard
records
DMC-412-A-00-75-00-00A-008A-A /
00002
2023-05-31
ALL
Customer support and services - Function
DMC-BHT-A-00-00-00-00A-011A-A /
00003
2023-05-31
ALL
Customer feedback, helicopter sales notice and
warranty - Administrative forms and data
DMC-BHT-A-00-00-00-00A-023A-A /
00004
2023-05-31
ALL
Use of a S1000D publication - Introduction
DMC-BHT-A-00-00-00-00A-018A-A /
00005
2023-05-31
ALL
Applicable to: ALL
ECCN EAR99
412-A-00-00-00-00A-00SA-A
28 OCT 2024 Page XV
BHT-412-CRO
Bulletin Record - Technical standard records
This Bulletin Record provides a current listing of applicable bulletins that have been incorporated in this manual. Subsequent
applicable bulletins will be incorporated in future revisions/reissues.
Table 1. ALERT SERVICE BULLETINS
ASB NUMBER
SUBJECT
DATE
(1)
Transmission oil lines 412-040-204-101
and 412-040-200-101, inspection and
revised clamping of
25 March 2016
412-16-172
1
This bulletin and all applicable bulletins issued before have been incorporated.
Table 2. TECHNICAL BULLETINS
TB NUMBER
SUBJECT
(1)
Engine Fuel Filter Drain System Reducer 16 November 2016
412-061-033-101, introduction of
412-16-238
1
DATE
This bulletin and all applicable bulletins issued before have been incorporated, except 412-96-137, 412-99-157,
412-00-168, 412-00-170, 412-03-189, 412-04-198, 412-04-200, 412-07-212, 412-12-226, and 412-12-227.
412-A-00-71-00-00A-008B-B
Page 00001.1-XVI 14 NOV 2023
Applicable to: ALL
ECCN EAR99
BHT-412-CRO
Temporary revision record - Technical standard records
This temporary revision record provides a current listing of active temporary revisions against the manual. Temporary revisions
which have been canceled/incorporated will only be maintained on the record until the next revision is issued. If there are no
temporary revisions shown on the record, this is confirmation that there are no temporary revisions issued against the manual.
Temporary Revision No.
Applicable to: ALL
ECCN EAR99
Title
Date issued
Date canceled
412-A-00-75-00-00A-008A-A
31 MAY 2023 Page 00002-XVII
BHT-412-CRO
Customer support and services - Function
1.
Customer support and services
Flying smart means that no matter where you are, or what time it is, you can make a call and get additional information,
clarification, or advice on a technical or operational issue concerning your helicopter or information contained in our
Technical Publications. Product Support Engineering (PSE) is just a phone call away and may be contacted as follows:
PSE Light (206/407/505):
Phone:
450-437-2862 or 800-363-8023 (US/Canada)
Fax:
450-433-0272
E-mail:
pselight@bellflight.com
PSE Intermediate (222/230/427/429/430):
Phone:
450-437-2077 or 800-463-3036 (US/Canada)
Fax:
450-433-0272
E-mail:
pseinter@bellflight.com
PSE Medium (204/205/212/412):
Phone:
450-437-6201 or 800-363-8028 (US/Canada)
Fax:
450-433-0272
E-mail:
psemedium@bellflight.com
BHT-A-00-00-00-00A-011A-A
Page 00003-XVIII 31 MAY 2023
Applicable to: ALL
ECCN EAR99
BHT-412-CRO
Customer feedback, helicopter sales notice and warranty - Administrative forms and data
THIS MANUAL APPLIES ONLY TO HELICOPTERS AND COMPONENTS MAINTAINED IN
ACCORDANCE WITH BELL APPROVED PROCEDURES USING BELL APPROVED PARTS.
ALL INSPECTION, REPAIR AND OVERHAUL PROCEDURES PUBLISHED BY BELL, INCLUDING
PART RETIREMENT LIFE, ARE BASED SOLELY ON THE USE OF BELL PARTS THAT HAVE BEEN
MAINTAINED USING BELL APPROVED DATA. THE DATA PUBLISHED HEREIN OR OTHERWISE
SUPPLIED BY BELL IS NOT APPLICABLE TO NON-BELL PARTS OR PARTS THAT HAVE BEEN
REPAIRED USING DATA AND/OR PROCESSES NOT APPROVED BY BELL.
BELL IS NOT RESPONSIBLE FOR ANY PART OTHER THAN THOSE THAT IT HAS APPROVED.
BEFORE PERFORMING ANY PROCEDURE CONTAINED IN THIS MANUAL YOU MUST INSPECT THE
AFFECTED PARTS AND RECORDS FOR EVIDENCE OF ANY MANUFACTURE, REPAIR, REWORK,
OR USE OF A PROCESS NOT APPROVED BY BELL.
IF YOU IDENTIFY OR SUSPECT THE USE OF PARTS NOT AUTHORIZED BY BELL, EITHER REMOVE
THE AFFECTED ITEM FROM THE AIRCRAFT OR OBTAIN INSTRUCTIONS FOR CONTINUED
AIRWORTHINESS FROM THE MANUFACTURER OR THE ORGANIZATION THAT APPROVED THE
REPAIR.
Refer to Figure 1, Figure 2, Figure 3, and Figure 4.
Applicable to: ALL
ECCN EAR99
BHT-A-00-00-00-00A-023A-A
31 MAY 2023 Page 00004-XIX
BHT-412-CRO
ICN-BHT-A-000000-A-97499-00002-F-001-01
Figure 1. Customer feedback (Sheet 1 of 2)
BHT-A-00-00-00-00A-023A-A
Applicable to: ALL
Page 00004-XX 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-BHT-A-000000-A-97499-00003-F-001-01
Figure 1. Customer feedback (Sheet 2 of 2)
Applicable to: ALL
ECCN EAR99
BHT-A-00-00-00-00A-023A-A
31 MAY 2023 Page 00004-XXI
BHT-412-CRO
ICN-BHT-A-000000-A-97499-00004-F-001-01
Figure 2. Sales notice (Sheet 1 of 2)
BHT-A-00-00-00-00A-023A-A
Page 00004-XXII 31 MAY 2023
Applicable to: ALL
ECCN EAR99
BHT-412-CRO
ICN-BHT-A-000000-A-97499-00005-F-001-01
Figure 2. Sales notice (Sheet 2 of 2)
Applicable to: ALL
ECCN EAR99
BHT-A-00-00-00-00A-023A-A
31 MAY 2023 Page 00004-XXIII
BHT-412-CRO
ICN-BHT-A-000000-A-97499-00006-F-001-01
Figure 3. Warranty (Sheet 1 of 1)
BHT-A-00-00-00-00A-023A-A
Page 00004-XXIV 31 MAY 2023
Applicable to: ALL
ECCN EAR99
BHT-412-CRO
ICN-BHT-A-000000-A-97499-00007-F-001-01
Figure 4. HELP page (Sheet 1 of 1)
Applicable to: ALL
ECCN EAR99
BHT-A-00-00-00-00A-023A-A
31 MAY 2023 Page 00004-XXV
BHT-412-CRO
Use of a S1000D publication - Introduction
1.
Use of a S1000D publication - General information
1.1.
Document structure
The breakdown of the helicopter into systems within the manuals is done under the S1000D specification
(S1000D-I9005-01000-00, Issue No. 4.0,4, may 12, 2009).
This publication is written in Simplified English and obeys the instructions given in document (ASD-STE100, Issue 6,
January 2013). The European Association of Aerospace Industries (ASD) prepared these documents.
All the data are included in data modules. A code identifies each data module.
1.1.1.
Data Module Code (DMC)
The Data Module Code (DMC) structure is shown in Table 1.
Table 1. DMC structure
BHT
A
29-10-01
00A
520A
A
Paragraph 1.1.1.1 Paragraph 1.1.1.2 Paragraph 1.1.1.3 Paragraph 1.1.1.4 Paragraph 1.1.1.5 Paragraph 1.1.1.6
1.1.1.1.
Model identification code
The model identification code is BHT.
1.1.1.2.
System difference code
The system difference code is a letter (letters I and 0 are not used).
This letter identifies two or more sub-systems that can be installed as alternative items because they do the same
function.
1.1.1.3.
Standard Numbering System (SNS) code
The Standard Numbering System (SNS) code includes three pairs of digits that show:
- The system (e.g., 29, hydraulic power)
- The subsystem and the sub-subsystem (e.g., 10, main hydraulic)
NOTE
When the sub-subsystem code is zero, the two digits show all of the subsystem.
-
1.1.1.4.
The component (e.g., 01, hydraulic reservoir filter module)
Disassembly code and disassembly code variant
1.1.1.4.1. Disassembly code
The disassembly code is a two-digit code.
The disassembly code shows the breakdown of a component, as follows:
- 00 - Data module for all of the helicopter, system, subsystem, or component.
- 01 - Data module for the first assembly that you remove from the component.
- 02 - Data module for the second assembly that you remove from the component.
Code 03 and the subsequent codes refer to the third, fourth, etc assembly that you remove from the component.
The disassembly code also identifies the data modules in sequence.
1.1.1.4.2. Disassembly code variant
The disassembly code variant is a letter (letters I and 0 are not used) that identifies alternative items.
These items are different, but the difference is too small to cause a change in the system difference code.
BHT-A-00-00-00-00A-018A-A
Page 00005-XXVI 31 MAY 2023
Applicable to: ALL
ECCN EAR99
BHT-412-CRO
1.1.1.5.
Information code and information code variant
1.1.1.5.1. Information code
The information code is a three-digit code.
The information code identifies the types of information you can find in the data module.
1.1.1.5.2. Information code variant
The information code variant is a letter (letters I and 0 are not used).
The information code variant is used for different data modules that are applicable to the same component and
type of operation.
1.1.1.6.
Item location code
You can find these item location codes:
- A on the helicopter.
- B on the removed assembly/component.
- D applicable to all the locations.
- Z is used as a generic item location code.
1.1.2.
List of Effective Data Modules (LOEDM)
Each chapter includes a List of Effective Data Modules (LOEDM) . The list shows the data module codes of all
the data modules in the chapter.
The LOEDM gives the information that follows for each data module:
- Technical name and information name columns. These two columns together give the title of the data module.
- Document identifier column. This column gives the data module code.
- The status of the data module. This column gives the information about the status of the data module (N for
new and C for changed).
- Issue date. This column gives the date of the data module changes.
- Applicability column. This column gives information about the applicability of the data module to different versions,
configurations, and modifications of the helicopter.
Applicable to: ALL
ECCN EAR99
BHT-A-00-00-00-00A-018A-A
31 MAY 2023 Page 00005-XXVII
BHT-412-CRO
Intentionally blank page
BHT-A-00-00-00-00A-018A-A
Page 00005-XXVIII 31 MAY 2023
Applicable to: ALL
ECCN EAR99
BHT-412-CRO
CHAPTER 01
GENERAL INFORMATION
COMPONENT REPAIR AND OVERHAUL MANUAL
Applicable to: ALL
412-A-01-00-00-00A-009A-A
ECCN EAR99
28 OCT 2024 Page 00006-1
BHT-412-CRO
Intentionally blank page
412-A-01-00-00-00A-009A-A
Applicable to: ALL
Page 00006-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
List of Effective Data Modules
The listed documents are included in issue 003, dated 2024-10-28, of this publication.
C = Changed data module, N = New data module
Document title
Data module code / Seq number
Issue date
Applicable
to
Introduction - Introduction
DMC-412-A-00-75-00-00A-018A-A /
00007
2023-05-31
ALL
Applicable to: ALL
ECCN EAR99
412-A-01-00-00-00A-00SA-A
28 OCT 2024 Page 1
BHT-412-CRO
Intentionally blank page
412-A-01-00-00-00A-00SA-A
Page 2 28 OCT 2024
Applicable to: ALL
ECCN EAR99
BHT-412-CRO
Introduction - Introduction
1.
Scope of Manual
This Component Repair and Overhaul Manual contains necessary data for repair and overhaul of components
and assemblies of the 412 helicopter. The removal and installation procedures are provided in the Maintenance
Manual. The Component Repair and Overhaul Manual Vendor Data, provides data for repair and overhaul of
vendor supplied components installed in the helicopter.
2.
Alert Service Bulletins
A list of Alert Service Bulletins issued against the Model 412 Series helicopters are listed in the appropriate Alert
Service Bulletin Indexes.
3.
Wear Limits
Throughout this manual, wear limits are provided to show the required fit between mating parts. It is not intended
that all dimensions be checked as a prescribed overhaul procedure; however, parts that show evidence of wear
of physical damage must be checked dimensionally.
4.
Consumable Materials
HANDLING AND STORAGE OF CONSUMABLE MATERIALS SHALL BE IN ACCORDANCE WITH
INSTRUCTIONS PROVIDED BY MANUFACTURER EXCEPT AS NOTED IN TEXT OF THIS MANUAL.
FAILURE TO COMPLY MAY RESULT IN INJURY.
Consumable materials required while performing maintenance are listed in text by name and item number such as
C-309. The number refers to item 309 in table 13-1 in BHT-ALL-SPM, Standard Practices Manual. This table provides
full nomenclature, specifications applicable, and a recommended source. Also, table 13-2 of BHT-ALL-SPM, Standard
Practices Manual lists acceptable alternates and other pertinent data for Bell adhesives. These are listed by Bell
Specification 299-947-XXX part numbers. Also, cure cycles, storage requirements, and usage information is included.
Applicable to: ALL
412-A-00-75-00-00A-018A-A
ECCN EAR99
31 MAY 2023 Page 00007-1
BHT-412-CRO
Intentionally blank page
412-A-00-75-00-00A-018A-A
Applicable to: ALL
Page 00007-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
CHAPTER 28
FUEL SYSTEM
COMPONENT REPAIR AND OVERHAUL MANUAL
Applicable to: ALL
412-A-28-00-00-00A-009A-A
ECCN EAR99
28 OCT 2024 Page 00008-1
BHT-412-CRO
Intentionally blank page
412-A-28-00-00-00A-009A-A
Applicable to: ALL
Page 00008-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
List of Effective Data Modules
The listed documents are included in issue 003, dated 2024-10-28, of this publication.
C = Changed data module, N = New data module
Document title
Data module code / Seq number
Issue date
Applicable
to
Fuel System - Fuel Cell Inspection, Repair, and
Storage
DMC-412-A-28-10-00-00A-028A-B /
00009
2023-05-31
ALL
Fuel Cell - Inspection
DMC-412-A-28-10-00-00A-280A-B /
00010
2023-05-31
ALL
Fuel Cell - Repair
DMC-412-A-28-10-00-00A-685A-B /
00011
2023-05-31
ALL
Fuel Cell - Storage
DMC-412-A-28-10-00-00A-810A-B /
00012
2023-05-31
ALL
Applicable to: ALL
ECCN EAR99
412-A-28-00-00-00A-00SA-A
28 OCT 2024 Page 1
BHT-412-CRO
Intentionally blank page
412-A-28-00-00-00A-00SA-A
Page 2 28 OCT 2024
Applicable to: ALL
ECCN EAR99
BHT-412-CRO
Fuel System - Fuel Cell Inspection, Repair, and Storage
This section contains inspection, repair, and storage instructions for fuel cell storage. For distribution and description,
refer to (412-MM, Chapter 28 and 412-MM, Chapter 28).
Applicable to: ALL
412-A-28-10-00-00A-028A-B
ECCN EAR99
31 MAY 2023 Page 00009-1
BHT-412-CRO
Intentionally blank page
412-A-28-10-00-00A-028A-B
Applicable to: ALL
Page 00009-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Fuel Cell - Inspection
Procedure
ONLY APPROVED EXPLOSION-PROOF TYPE LIGHTS ARE TO BE USED NEAR OPEN FUEL CELLS
AND FUEL LINES.
DO NOT HANDLE FUEL CELL WHEN AMBIENT TEMPERATURE IS BELOW 65°F (18°C).
1.
Inspect fuel cell for deterioration, evidence of seepage, and mechanical damage.
2.
Inspect threaded inserts for damaged threads and secure installation in cell.
3.
Inspect fuel cell for damage that may have occurred during crating or removal from shipping container.
Applicable to: ALL
412-A-28-10-00-00A-280A-B
ECCN EAR99
31 MAY 2023 Page 00010-1
BHT-412-CRO
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412-A-28-10-00-00A-280A-B
Applicable to: ALL
Page 00010-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Fuel Cell - Repair
Procedure
NOTE
If you return the part to Bell, refer to IL-GEN-04-98 for applicable shipping information and to obtain a
Return Material Authorization (RMA) number.
NOTE
If you return the part to Amfuel (American Fuel Cells and Coated Fabrics), refer to https://www.amfuel.com
for a list of repair centers.
1.
Field repair of fuel cells is not authorized. Return the part to the manufacturer, one of its authorized service centers,
or Bell for evaluation and possible repair.
Applicable to: ALL
412-A-28-10-00-00A-685A-B
ECCN EAR99
31 MAY 2023 Page 00011-1
BHT-412-CRO
Intentionally blank page
412-A-28-10-00-00A-685A-B
Applicable to: ALL
Page 00011-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Fuel Cell - Storage
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Lubricating oil
C-009
AR
Remarks
Procedure
1.
When a cell that has contained fuel is to remain empty for more than 3 days, the inner surface of the cell should be
fogged with light lubricating oil (C-009) to prevent deterioration caused by drying out. Do not leave the cell collapsed.
If it is not to be replaced in the helicopter immediately, the cell should be installed in a stand or a container such as is
normally used for shipping. Restore cell to normal shape.
2.
Do not store fuel cells where they will be subjected to heat or extreme humidity.
Applicable to: ALL
412-A-28-10-00-00A-810A-B
ECCN EAR99
31 MAY 2023 Page 00012-1
BHT-412-CRO
Intentionally blank page
412-A-28-10-00-00A-810A-B
Applicable to: ALL
Page 00012-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
CHAPTER 29
HYDRAULIC SYSTEM
COMPONENT REPAIR AND OVERHAUL MANUAL
Applicable to: ALL
412-A-29-00-00-00A-009A-A
ECCN EAR99
28 OCT 2024 Page 00013-1
BHT-412-CRO
Intentionally blank page
412-A-29-00-00-00A-009A-A
Applicable to: ALL
Page 00013-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
List of Effective Data Modules
The listed documents are included in issue 003, dated 2024-10-28, of this publication.
C = Changed data module, N = New data module
Document title
Data module code / Seq number
Issue date
Applicable
to
Hydraulic System - Hydraulic System
DMC-412-A-29-00-00-00A-028A-B /
00014
2023-05-31
ALL
Hydraulic System - Hydraulic System
Components
DMC-412-A-29-00-00-05A-028A-B /
00015
2023-05-31
ALL
Hydraulic Accumulator - Disassembly
DMC-412-A-29-10-00-00A-530A-B /
00016
2023-05-31
ALL
Hydraulic Accumulator - Cleaning
DMC-412-A-29-10-00-00A-258A-B /
00017
2023-05-31
ALL
Hydraulic Accumulator - Inspection
DMC-412-A-29-10-00-00A-280A-B /
00018
2023-05-31
ALL
Hydraulic Accumulator - Repair
DMC-412-A-29-10-00-00A-685A-B /
00019
2023-05-31
ALL
Hydraulic Accumulator - Assembly
DMC-412-A-29-10-00-00A-710A-B /
00020
2023-05-31
ALL
Dual Hydraulic Actuator Mounting Bracket and
Nut - Inspection
DMC-412-A-29-10-00-05A-280A-B /
00021
2023-05-31
ALL
Dual Hydraulic Actuator Mounting Bracket and
Nut - Repair
DMC-412-A-29-10-00-05A-685A-B /
00022
2023-05-31
ALL
Non-Pressurizing Hydraulic Reservoir
(205-076-135) - Inspection
DMC-412-A-29-10-00-02A-280A-B /
00023
2023-05-31
ALL
Non-Pressurizing Hydraulic Reservoir
(205-076-135) - Repair
DMC-412-A-29-10-00-02A-685A-B /
00024
2023-05-31
ALL
Rotor Brake Master Cylinder - Disassembly
DMC-412-A-29-10-00-03A-530A-B /
00025
2023-05-31
ALL
Rotor Brake Master Cylinder - Inspection
DMC-412-A-29-10-00-03A-280A-B /
00026
2023-05-31
ALL
Rotor Brake Master Cylinder - Repair
DMC-412-A-29-10-00-03A-685A-B /
00027
2023-05-31
ALL
Rotor Brake Master Cylinder - Assembly
DMC-412-A-29-10-00-03A-710A-B /
00028
2023-05-31
ALL
Rotor Brake Master Cylinder - Adjustment
DMC-412-A-29-10-00-03A-271A-B /
00029
2023-05-31
ALL
Applicable to: ALL
ECCN EAR99
412-A-29-00-00-00A-00SA-A
28 OCT 2024 Page 1
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412-A-29-00-00-00A-00SA-A
Page 2 28 OCT 2024
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ECCN EAR99
BHT-412-CRO
Hydraulic System - Hydraulic System
Refer to the BHT-412-CR&O-V when repairs, overhaul, special tools, spare parts, or service manuals for the module
assembly, main hydraulic actuators (cyclic and collective), hydraulic pumps anti-torque actuator and pressure
operated check valve assembly are required.
Applicable to: ALL
412-A-29-00-00-00A-028A-B
ECCN EAR99
31 MAY 2023 Page 00014-1
BHT-412-CRO
Intentionally blank page
412-A-29-00-00-00A-028A-B
Applicable to: ALL
Page 00014-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Hydraulic System - Hydraulic System Components
This section contains repair and overhaul instructions for hydraulic system components.
Applicable to: ALL
412-A-29-00-00-05A-028A-B
ECCN EAR99
31 MAY 2023 Page 00015-1
BHT-412-CRO
Intentionally blank page
412-A-29-00-00-05A-028A-B
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Page 00015-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Hydraulic Accumulator - Disassembly
Procedure
1.
Remove lockwire between lock (6, Figure 1) and nut (5).
2.
Back off nut (5) until lock (6) is free of cap (1).
3.
Remove cap (1).
4.
Remove spring (2) and piston (3) from body (7). Remove packing (4) from piston.
Applicable to: ALL
412-A-29-10-00-00A-530A-B
ECCN EAR99
31 MAY 2023 Page 00016-1
BHT-412-CRO
ICN-412-A-291000-B-97499-00001-A-001-01
Figure 1. Hydraulic Accumulator (Sheet 1 of 1)
412-A-29-10-00-00A-530A-B
Applicable to: ALL
Page 00016-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Hydraulic Accumulator - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Drycleaning solvent
C-304
AR
Remarks
Procedure
1.
Clean all parts of hydraulic accumulator with drycleaning solvent (C-304).
2.
Dry all parts with filtered, compressed air.
Applicable to: ALL
412-A-29-10-00-00A-258A-B
ECCN EAR99
31 MAY 2023 Page 00017-1
BHT-412-CRO
Intentionally blank page
412-A-29-10-00-00A-258A-B
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Page 00017-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Hydraulic Accumulator - Inspection
Procedure
NOTE
Excessive wear or any obvious deformation or deterioration of parts which may render the unit inoperative
must be replaced.
1.
Inspect all surfaces and threaded areas for damage, galling, burrs, excessive wear, and corrosion. Corrosion or
damage to the spring (2, Figure 1) is not permitted.
2.
Inspect accumulator in accordance with Figure 2.
NOTE
Refer to BHT-ALL-SPM, Standard Practices Manual for approved fluorescent penetrant material (Post
Emulsified Penetrant System).
3.
Inspect the following parts by fluorescent penetrant method:
- Cap (1, Figure 1)
- Piston (3, Figure 1)
- Nut (5, Figure 1)
- Body (7, Figure 1)
Applicable to: ALL
412-A-29-10-00-00A-280A-B
ECCN EAR99
31 MAY 2023 Page 00018-1
BHT-412-CRO
ICN-412-A-291000-B-97499-00001-A-001-01
Figure 1. Hydraulic Accumulator (Sheet 1 of 1)
412-A-29-10-00-00A-280A-B
Applicable to: ALL
Page 00018-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-291000-B-97499-00002-A-001-01
Figure 2. Damage Limits - Hydraulic Accumulator (Sheet 1 of 1)
Applicable to: ALL
412-A-29-10-00-00A-280A-B
ECCN EAR99
31 MAY 2023 Page 00018-3
BHT-412-CRO
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412-A-29-10-00-00A-280A-B
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Page 00018-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Hydraulic Accumulator - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Chemical film material
Drycleaning solvent
Abrasive cloth or paper
C-100
C-304
C-423
AR
AR
AR
Remarks
Procedure
1.
Remove minor nicks and scratches with 600 to 800 grit abrasive cloth or paper (C-423).
2.
After completion of repair, clean parts with drycleaning solvent (C-304).
3.
Repair damage to anodized finish by applying (brush-on) chemical film material (C-100).
4.
Replace all parts that cannot be reworked to meet repair criteria. Refer to Figure 1.
5.
Discard packing at overhaul regardless of condition.
6.
Replace parts if thread damage exceeds 50% of one thread.
Applicable to: ALL
412-A-29-10-00-00A-685A-B
ECCN EAR99
31 MAY 2023 Page 00019-1
BHT-412-CRO
ICN-412-A-291000-B-97499-00002-A-001-01
Figure 1. Damage Limits - Hydraulic Accumulator (Sheet 1 of 1)
412-A-29-10-00-00A-685A-B
Applicable to: ALL
Page 00019-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Hydraulic Accumulator - Assembly
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Grease
Hydraulic fluid
Lockwire
C-001
C-002
C-405
AR
AR
AR
Remarks
Procedure
1.
Lubricate packing (4, Figure 1) with hydraulic fluid (C-002). Place packing on piston (3). Insert piston (3) into body (7).
2.
Coat spring (2) with grease (C-001) and place over end of piston (3) inside body (7).
3.
Assemble nut (5) and lock (6) on body (7), turned far enough onto threads of body to keep lock (6) clear of cap (1)
during installation.
4.
Thread cap (1) on body (7) until bottomed out, then back off until nearest key slot aligns with lock (6). Turn nut (5)
toward cap (1) until lock (6) is in slot of cap.
5.
Torque nut (5), 100 to 200 in. lbs. (11.30 to 22.60 Nm). Secure lock (6) to nut (5) with lockwire (C-405).
Applicable to: ALL
412-A-29-10-00-00A-710A-B
ECCN EAR99
31 MAY 2023 Page 00020-1
BHT-412-CRO
ICN-412-A-291000-B-97499-00001-A-001-01
Figure 1. Hydraulic Accumulator (Sheet 1 of 1)
412-A-29-10-00-00A-710A-B
Applicable to: ALL
Page 00020-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Dual Hydraulic Actuator Mounting Bracket and Nut - Inspection
Procedure
1.
Inspect all surfaces and threaded areas for damage, excessive wear and corrosion (refer to Figure 1).
2.
No cracks are allowed.
Applicable to: ALL
412-A-29-10-00-05A-280A-B
ECCN EAR99
31 MAY 2023 Page 00021-1
BHT-412-CRO
ICN-412-A-291000-B-97499-00003-A-001-01
Figure 1. Damage Limits - Dual Hydraulic Actuator Mounting Bracket and Nut (Sheet 1 of 1)
412-A-29-10-00-05A-280A-B
Applicable to: ALL
Page 00021-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Dual Hydraulic Actuator Mounting Bracket and Nut - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Chemical film material
Epoxy polyamide primer
Drycleaning solvent
Abrasive cloth or paper
C-100
C-204
C-304
C-423
AR
AR
AR
AR
Remarks
Procedure
1.
Remove all mechanical or corrosion damage (within limits) using 400 to 600 grit abrasive cloth or paper (C-423).
Refer to Figure 1.
2.
After completion of repair, clean parts with drycleaning solvent (C-304).
3.
Repair damage to anodized finish by applying chemical film material (C-100).
4.
Apply one coat of epoxy polyamide primer (C-204) to repaired areas except for mounting holes.
Applicable to: ALL
412-A-29-10-00-05A-685A-B
ECCN EAR99
31 MAY 2023 Page 00022-1
BHT-412-CRO
ICN-412-A-291000-B-97499-00003-A-001-01
Figure 1. Damage Limits - Dual Hydraulic Actuator Mounting Bracket and Nut (Sheet 1 of 1)
412-A-29-10-00-05A-685A-B
Applicable to: ALL
Page 00022-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Non-Pressurizing Hydraulic Reservoir (205-076-135) - Inspection
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Resin coating
C-042
AR
Remarks
Procedure
NOTE
The reservoir 205-076-058 is made of resin and no damage is allowed. If any damage is found, replace
the reservoir.
NOTE
The reservoir 205-076-135 is made of magnesium alloy. resin coating (C-042) is applied on the interior
and exterior surfaces of the reservoir.
1.
Visually inspect the interior of the reservoir for corrosion as follows:
1.1.
Corrosion depth greater than 0.060 inch (1.52 mm) is nonrepairable. The reservoir shall be replaced.
1.2.
Corrosion depth of 0.060 inch (1.52 mm) or less may be repaired. However, multiple cleanup areas shall be a
minimum of 0.50 inch (12.7 mm) away from the edge of each other to a limit of four per reservoir.
2.
Visually inspect the reservoir exterior for corrosion or dents as follows:
2.1.
For corrosion or dents less than 0.020 inch (0.51 mm), no repair is necessary.
2.2.
Dents 0.020 to 0.060 inch (0.51 to 1.52 mm) shall be reworked.
2.3.
Dents greater than 0.060 inch (1.52 mm) are not repairable. Replace the reservoir.
Applicable to: ALL
412-A-29-10-00-02A-280A-B
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412-A-29-10-00-02A-280A-B
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Page 00023-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Non-Pressurizing Hydraulic Reservoir (205-076-135) - Repair
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Glass Bead Equipment
Commercial
1
Remarks
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Resin coating
Chromic acid treatment
Epoxy polyamide primer
Aliphatic naphtha
Sealant
MEK
Cleaner
Sealant
Tape
Glass beads
C-042
C-103
C-204
C-305
C-308
C-309
C-348
C-251
C-462
C-470
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
Remarks
Procedure
NOTE
The reservoir 205-076-058 is made of resin and no damage is allowed. If any damage is found, replace
the reservoir.
NOTE
The reservoir 205-076-135 is made of magnesium alloy. resin coating (C-042) is applied on the interior
and exterior surfaces of the reservoir.
1.
Repair the reservoir exterior surface as follows:
1.1.
Polish to blend out the defect. Measure the depth of the material removed.
1.2.
Remove additional material to the same depth as previously removed, up to 0.040 inch (1.02 mm) maximum.
1.3.
Apply chromic acid treatment (C-103) (Dow 19) for magnesium surfaces in accordance with the BHT-ALL-SPM,
Chapter 3, Standard Practices Manual.
1.4.
Apply resin coating as follows:
1.4.1.
Remove all grease or oil with MEK (C-309) or aliphatic naphtha (C-305).
1.4.2.
The parts should not be handled in any manner that will allow fingerprints, dirt, dust, and other foreign substances
to contaminate the surface to be coated.
1.4.3.
Apply resin coating (C-042) at room temperature either by brushing or spraying.
1.4.4.
Air dry (cure) at room temperature for at least 1 hour.
1.5.
Mask off all the parts having threads.
1.6.
Apply three coats of epoxy polyamide primer (C-204).
1.7.
Visually examine the vent screen. Any holes due to damage, requires replacement of the screen.
1.8.
Verify that the screen is secured by a point stake in at least three places.
1.9.
Replace the sight plug if damaged.
Applicable to: ALL
412-A-29-10-00-02A-685A-B
ECCN EAR99
31 MAY 2023 Page 00024-1
BHT-412-CRO
1.10.
Replace the filler cap if corroded.
1.11.
If the adapter is corroded, return the reservoir to Bell for replacement.
NOTE
Do not apply primer to the threaded areas or fitting bores.
2.
Repair the external surfaces coatings (organic) by applying a coat of epoxy polyamide primer (C-204).
3.
Repair the reservoir interior surface as follows:
3.1.
Inspection criteria for the reservoir:
3.1.1.
Remove all fittings and associated hardware from the reservoir.
NOTE
The maximum allowable material removed shall not exceed 0.100 inch (2.54 mm) at the deepest point.
3.1.2.
Prepare the internal surface to be reworked by removing corrosion with glass beads (C-470), size 11 to 13. Do not
allow the blast pressure to exceed 30 to 50 PSI (207 to 345 kPa).
3.1.3.
Apply a hot chromic acid treatment (C-103) to the surface (BHT-ALL-SPM, Chapter 3, Standard Practices Manual).
3.1.4.
Inspect the affected area to determine re-workability. Any remaining corrosion present after accomplishing the
preceding steps will be cause for scrapping the reservoir.
3.2.
Reservoir surfacing procedure:
3.2.1.
Remove oils and greases with MEK (C-309).
3.2.2.
Clean the internal surfaces of the reservoir with cleaner (C-348). Clean the internal surfaces using an alternate
method of 1.5 to 2.5 ounces/gallons (44.36 to 74 ml/L) sodium carbonate in heated water 190 to 212°F (88 to 100°C).
Thoroughly rinse the reservoir with hot water following the cleaning.
3.2.3.
Mask off all exposed threaded areas and fitting bores on the reservoir with tape (C-462) to ensure no chemical
film treatment comes in contact with these surfaces.
3.2.4.
Apply chemical film treatment (DOW 17), treatment provisions (MIL-M-45202, Type II, Class D) using a BHT
authorized repair facility or contact Product Support Engineering (PSE) for further information on the anodic treatment.
3.2.5.
Rinse the reworked parts with room temperature water, followed by a dip in hot water 180°F (82°C), maximum, to
facilitate drying. Use a dry heat of 325°F (163°C) for 30 minutes to remove all moisture.
NOTE
The method of resin application is by dipping.
3.2.6.
Allow the reservoirs to cool to 110 to 140°F (43 to 60°C) and apply one coat of resin coating (C-042). Adjust the resin
viscosity to produce a coating thickness of 0.0002 to 0.00035 inch (0.005 to 0.0089 mm) when tested on a glass plate.
3.2.7.
Drain the reservoirs and allow to dry at room temperature for 1 hour.
3.2.8.
Partially cure the resin coating by heating the reservoirs to 270 to 290°F (132 to 143°C) for 20 minutes.
3.2.9.
Allow the reservoirs to cool to 110 to 140°F (43 to 60°C) and apply a second coat of resin coating (C-042).
3.2.10.
Drain and dry at room temperature for 1 hour.
3.2.11.
Repeat Step 3.2.8. through Step 3.2.10..
3.2.12.
Cure the resin coating by heating the reservoirs at 310 to 330°F (154 to 166°C) for 1 hour.
3.2.13.
Remove the masking tape from the threads and fitting bores.
3.3.
Repair the reservoir attachment lugs as follows:
3.3.1.
The horizontal pad on the lug may be machined down to a minimum thickness of 0.200 inch (5.08 mm). Apply
chemical film treatment (DOW 19) (BHT-ALL-SPM, Standard Practices Manual).
412-A-29-10-00-02A-685A-B
Applicable to: ALL
Page 00024-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
3.3.2.
The vertical gussets may be machined down to a minimum thickness of 0.070 inch (1.78 mm). Apply chromic acid
treatment (C-103) (Dow 19) (BHT-ALL-SPM, Chapter 3, Standard Practices Manual).
3.3.3.
Coat the reworked area with resin coating (C-042) and allow to air dry. The horizontal flange may be built up by
installing an aluminum alloy washer AN960D to the flange with sealant (C-251) or sealant (C-308), to compensate
for the grip length on the attaching bolts.
Applicable to: ALL
412-A-29-10-00-02A-685A-B
ECCN EAR99
31 MAY 2023 Page 00024-3
BHT-412-CRO
Intentionally blank page
412-A-29-10-00-02A-685A-B
Applicable to: ALL
Page 00024-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Rotor Brake Master Cylinder - Disassembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Repair Kit
Pressure Gauge
204-1653-1
Commercial
1
1
Remarks
0 to 500 PSI (0 to 3447 kPa) graduated in 10 PSI
(69 kPa) increments
Procedure
1.
Remove the filler cap (9, Figure 1) and drain the fluid from the cylinder.
2.
Remove the handle pivot bolt (15). Remove the handle and piston assembly (11) as a unit.
3.
Remove the link (14) from the handle and piston.
EXERCISE CARE WHEN REMOVING THE CAP (13). THE SPRING (10) EXERTS APPROXIMATELY
250 POUNDS (1112.06 N) OF FORCE ON THE CAP.
4.
Position the piston assembly (11) in the arbor press with the cap (13) up. Apply sufficient pressure to relieve the
pressure on the retaining ring (12).
5.
Carefully remove the retaining ring (12) and relieve the pressure on the cap.
6.
Apply approximately 35 pounds (155.69 N) of pressure to the sleeve (5), remove the retaining ring (25), and relieve
the pressure on the sleeve.
7.
Remove the sleeve (5) and springs (18 and 20). Check for washers at the base of the spring (18).
8.
Remove the retainer (19), spring (21), and adjustable poppet valve (23).
9.
Apply approximately 5 pounds (22.24 N) of pressure to the piston (8) and remove the stop (16). Remove the piston
along with the spring (6).
10.
Remove the retaining ring (2) and plug (1).
NOTE
Do not remove the pin (30) unless damaged or excessively worn.
11.
Remove and discard all packings and glyd rings except the packings (4 and 22). Discard the packings (4 and
22) only if damaged.
Applicable to: ALL
412-A-29-10-00-03A-530A-B
ECCN EAR99
31 MAY 2023 Page 00025-1
BHT-412-CRO
ICN-412-A-291000-B-97499-00004-A-001-01
Figure 1. Rotor Brake Master Cylinder Assembly (Sheet 1 of 1)
412-A-29-10-00-03A-530A-B
Applicable to: ALL
Page 00025-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Rotor Brake Master Cylinder - Inspection
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Drycleaning solvent
C-304
AR
Remarks
Procedure
CLEAN HYDRAULIC COMPONENTS USING drycleaning solvent (C-304) ONLY.
1.
Clean all components using drycleaning solvent (C-304).
2.
Inspect all parts for cracks or other damage. No cracks are allowed.
3.
Inspect springs for condition
4.
Inspect housing and components for serviceability Figure 1.
5.
Glyd ring and packing working surfaces shall be free from pitting or other imperfections and shall conform to a
finish of 15 RMS.
6.
Inspect bolts for excessive wear and thread damage.
Applicable to: ALL
412-A-29-10-00-03A-280A-B
ECCN EAR99
31 MAY 2023 Page 00026-1
BHT-412-CRO
ICN-412-A-291000-B-97499-00005-A-001-01
Figure 1. Damage Limits - Rotor Brake Master Cylinder Assembly (Sheet 1 of 2)
412-A-29-10-00-03A-280A-B
Applicable to: ALL
Page 00026-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-291000-B-97499-00006-A-001-01
Figure 1. Damage Limits - Rotor Brake Master Cylinder Assembly (Sheet 2 of 2)
Applicable to: ALL
412-A-29-10-00-03A-280A-B
ECCN EAR99
31 MAY 2023 Page 00026-3
BHT-412-CRO
Intentionally blank page
412-A-29-10-00-03A-280A-B
Applicable to: ALL
Page 00026-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Rotor Brake Master Cylinder - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Abrasive cloth or paper
C-423
AR
Remarks
Procedure
NOTE
The components of the master cylinder are not repairable. Unserviceable components shall be replaced
with like serviceable items.
1.
Replace cracked or otherwise unserviceable components.
2.
Replace all packings and glyd rings 412-A-29-10-00-03A-280A-B / 00026.
3.
Replace unserviceable springs.
4.
Remove minor scratches and pitting from glyd ring and packing working surfaces using 350 grit abrasive cloth
or paper (C-423).
5.
Replace all bolts that are unserviceable.
Applicable to: ALL
412-A-29-10-00-03A-685A-B
ECCN EAR99
31 MAY 2023 Page 00027-1
BHT-412-CRO
Intentionally blank page
412-A-29-10-00-03A-685A-B
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Page 00027-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Rotor Brake Master Cylinder - Assembly
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Remarks
Hydraulic fluid
C-002
AR
Hydraulic fluid
C-072
AR
Refer to BHT-412-MM, Chapter 12 for information
on usage and mixing of hydraulic fluid (C-002) and
hydraulic fluid (C-072).
Refer to BHT-412-MM, Chapter 12 for information
on usage and mixing of hydraulic fluid (C-002) and
hydraulic fluid (C-072).
Petrolatum
C-008
AR
Procedure
1.
Install spring (6, Figure 1) and piston (8) in main housing (7).
USE CARE WHEN HANDLING OR INSTALLING PACKINGS AND GLYD RINGS TO AVOID NICKS,
CUTS, OR OTHER DAMAGE.
2.
Install new packing on stop (16). Compress piston (8) sufficiently to clear hole for stop. Install and tighten stop.
NOTE
Apply a light coat of hydraulic fluid (C-002) or hydraulic fluid (C-072), or petrolatum (C-008) to surfaces
of all internal components.
3.
Install adjustable poppet valve (23), spring (21), and retainer (19) into poppet valve (24). Turn retainer clockwise until
outer surface of retainer is flush with end of poppet valve.
4.
Install springs (18 and 20) in piston (11).
5.
Install poppet assembly from Step 3. in sleeve (5).
6.
Install poppet and sleeve assembly in piston (11). While compressing sleeve into piston, install retaining ring (25).
7.
Install spring (10) and cap (13) in piston assembly (11).
8.
Position piston assembly (11) in an arbor press with cap (13) up. Apply sufficient force (approximately 250 pounds
(1112.06 N)) to compress spring and install retaining ring (12).
9.
Install link (14) and handle (26) on piston assembly (11).
10.
Install piston assembly (11) in housing (7) and install handle pivot bolt (15) and cotter pin.
11.
Install plug (1) and retaining ring (2).
12.
Install plug (3) and filler cap (9).
13.
Install pin (30), spring (29), washer (28), and spring pin (27) if these parts were removed during disassembly.
Applicable to: ALL
412-A-29-10-00-03A-710A-B
ECCN EAR99
31 MAY 2023 Page 00028-1
BHT-412-CRO
ICN-412-A-291000-B-97499-00004-A-001-01
Figure 1. Rotor Brake Master Cylinder Assembly (Sheet 1 of 1)
412-A-29-10-00-03A-710A-B
Applicable to: ALL
Page 00028-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Rotor Brake Master Cylinder - Adjustment
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Remarks
Hydraulic fluid
C-002
AR
Hydraulic fluid
C-072
AR
Refer to BHT-412-MM, Chapter 12 for information
on usage and mixing of hydraulic fluid (C-002) and
hydraulic fluid (C-072).
Refer to BHT-412-MM, Chapter 12 for information
on usage and mixing of hydraulic fluid (C-002) and
hydraulic fluid (C-072).
Procedure
1.
Install pressure gauge (0 to 500 PSI (0 to 3447 kPa)) in outlet of master cylinder.
2.
Fill cylinder with hydraulic fluid (C-002) or hydraulic fluid (C-072), and bleed all air from cylinder and gauge.
3.
Actuate handle (26, Figure 1) one complete stroke and check pressure. One stroke shall generate 240 to 260
PSI (1655 to 1792 kPa) and shall maintain 150 PSI (1034 kPa) minimum for 3 minutes in over center position. If
pressure is not within limits, accomplish the following:
3.1.
Drain all fluid from cylinder.
3.2.
Remove handle pivot bolt (15) and remove piston and handle as a unit.
3.3.
Apply approximately 35 pounds (155.69 N) of force to sleeve (5) and remove retaining ring (25).
3.4.
Remove sleeve (5) and poppet valve (24). Remove poppet from sleeve.
AS RETAINER IS TURNED IN CLOCKWISE DIRECTION, ADJUSTMENT SENSITIVITY INCREASES
SIGNIFICANTLY AS RETAINER NEARS POPPET.
NOTE
When retainer (19) is approximately flush with surface of poppet valve (24), turning retainer clockwise
one full turn increases pressure approximately 40 PSI (276 kPa) and turning retainer counterclockwise
decreases pressure approximately 40 PSI (276 kPa).
4.
Adjust retainer (19) as required to obtain output pressure within limits.
NOTE
After final adjustment, retainer (19) shall be flush or slightly below the surface of poppet valve (24).
5.
Inspect retainer (19) for position. If retainer is more than 0.06 inch (1.5 mm) below surface of poppet valve (24),
install washers AN960PD8, under spring in poppet, as required to bring retainer flush with or within 0.016 inch (0.41
mm) of surface of poppet valve.
6.
Install poppet valve (24) in sleeve (5).
7.
Install sleeve and poppet assembly in piston (8) and install retaining ring (25).
8.
Install piston assembly in housing and install pivot bolt (15). Tighten pivot bolt nut finger tight with minimum end play.
9.
Recheck adjustment by accomplishing Step 2. and Step 3.. If pressure is not within limits, accomplish Step 3.
through Step 8. as required.
10.
Remove pressure gauge and drain hydraulic fluid.
11.
Cap or seal all openings.
Applicable to: ALL
412-A-29-10-00-03A-271A-B
ECCN EAR99
31 MAY 2023 Page 00029-1
BHT-412-CRO
ICN-412-A-291000-B-97499-00004-A-001-01
Figure 1. Rotor Brake Master Cylinder Assembly (Sheet 1 of 1)
412-A-29-10-00-03A-271A-B
Applicable to: ALL
Page 00029-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
CHAPTER 32
LANDING GEAR
COMPONENT REPAIR AND OVERHAUL MANUAL
Applicable to: ALL
412-A-32-00-00-00A-009A-A
ECCN EAR99
28 OCT 2024 Page 00030-1
BHT-412-CRO
Intentionally blank page
412-A-32-00-00-00A-009A-A
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Page 00030-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
List of Effective Data Modules
The listed documents are included in issue 003, dated 2024-10-28, of this publication.
C = Changed data module, N = New data module
Document title
Data module code / Seq number
Issue date
Applicable
to
Ground Handling Wheel Assembly
(214-706-104-003) - Inspection
DMC-412-A-32-40-00-00A-280A-B /
00031
2023-05-31
ALL
Ground Handling Wheel Assembly
(214-706-104-003) - Lubrication
DMC-412-A-32-40-00-00A-240A-B /
00032
2023-05-31
ALL
Wheel and Tire Assembly - Removal
DMC-412-A-32-40-00-00A-520A-B /
00033
2023-05-31
ALL
Wheel and Tire Assembly - Installation
DMC-412-A-32-40-00-00A-720A-B /
00034
2023-05-31
ALL
Tubeless Tire - Removal
DMC-412-A-32-40-00-01A-520A-B /
00035
2023-05-31
ALL
Tubeless Tire - Installation
DMC-412-A-32-40-00-01A-720A-B /
00036
2023-05-31
ALL
Tube Type Tire - Removal
DMC-412-A-32-40-00-02A-520A-B /
00037
2023-05-31
ALL
Tube Type Tire - Installation
DMC-412-A-32-40-00-02A-720A-B /
00038
2023-05-31
ALL
Ground Handling Wheel Assembly Pump Removal
DMC-412-A-32-40-00-03A-520A-B /
00039
2023-05-31
ALL
Ground Handling Wheel Assembly Pump Installation
DMC-412-A-32-40-00-03A-720A-B /
00040
2023-05-31
ALL
Ground Handling Wheel Assembly Decals Installation
DMC-412-A-32-40-00-04A-720A-B /
00041
2023-05-31
ALL
Ground Handling Wheel Assembly Ram and
Trunnion - Removal
DMC-412-A-32-40-00-05A-520A-B /
00042
2023-05-31
ALL
Ground Handling Wheel Assembly Ram and
Trunnion - Installation
DMC-412-A-32-40-00-05A-720A-B /
00043
2023-05-31
ALL
Ground Handling Wheel Assembly Axles Removal
DMC-412-A-32-40-00-06A-520A-B /
00044
2023-05-31
ALL
Ground Handling Wheel Assembly Axles Installation
DMC-412-A-32-40-00-06A-720A-B /
00045
2023-05-31
ALL
Ground Handling Wheel Assembly Bushings Removal
DMC-412-A-32-40-00-07A-520A-B /
00046
2023-05-31
ALL
Ground Handling Wheel Assembly Bushings Installation
DMC-412-A-32-40-00-07A-720A-B /
00047
2023-05-31
ALL
Applicable to: ALL
ECCN EAR99
412-A-32-00-00-00A-00SA-A
28 OCT 2024 Page 1
BHT-412-CRO
Intentionally blank page
412-A-32-00-00-00A-00SA-A
Page 2 28 OCT 2024
Applicable to: ALL
ECCN EAR99
BHT-412-CRO
Ground Handling Wheel Assembly (214-706-104-003) - Inspection
Procedure
NOTE
Refer to BHT-412-MM for inspection and repair of landing gear.
NOTE
Overhaul instructions for ground handling wheels contained in this chapter are limited to inspection and
replacement of faulty parts.
1.
Inspect tire and wheel assemblies (1 and 5, Figure 1) for tire damage and deterioration when pneumatic tires
are installed. Check both tires for inflation to 75 psi (517.1067 kilopascals). Inspect wheels for corrosion, cracks,
and secure installation on axles.
2.
Inspect pump (2) for adequate supply of hydraulic fluid, corrosion, obvious mechanical damage, and secure
installation on cradle assembly (11 ).
3.
Inspect cradle assembly (11) and all detail parts shown on view B for obvious damage, and secure installation.
4.
Inspect bushings (47, 48, 49, and 51) for obvious wear and for secure installation.
5.
Inspect decals (19 and 20) for legibility and secure installation.
6.
Inspect pin (10) and spring pin (50) to assure they are not sheared and that pin is adequately secured.
7.
Inspect lubrication fittings (27, 28, and 35) and also fitting (not illustrated) that is opposite fitting (35) for secure
installation and for damage.
8.
Perform functional check of ground handling wheels. Install ground handling wheel assembly on helicopter landing
gear skid and raise helicopter. Inspect for proper engagement and operation of release pin (3) and pin (10). Inspect
for hydraulic leaks. If wheel assembly will not raise helicopter, and the pump has supply of hydraulic fluid, cause is
probably internal hydraulic leak in pump (2).
Applicable to: ALL
412-A-32-40-00-00A-280A-B
ECCN EAR99
31 MAY 2023 Page 00031-1
BHT-412-CRO
ICN-412-A-324000-B-97499-00001-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 1 of 2)
412-A-32-40-00-00A-280A-B
Applicable to: ALL
Page 00031-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-324000-B-97499-00002-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 2 of 2)
Applicable to: ALL
412-A-32-40-00-00A-280A-B
ECCN EAR99
31 MAY 2023 Page 00031-3
BHT-412-CRO
Intentionally blank page
412-A-32-40-00-00A-280A-B
Applicable to: ALL
Page 00031-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Ground Handling Wheel Assembly (214-706-104-003) - Lubrication
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Grease
C-001
AR
Remarks
Procedure
NOTE
Refer to BHT-412-MM for inspection and repair of landing gear.
NOTE
Overhaul instructions for ground handling wheels contained in this chapter are limited to inspection and
replacement of faulty parts.
1.
Use hand grease gun and lubricate with grease (C-001).
2.
Lubricate fittings (27, 28 and 35, Figure 1). Also, lubricate opposite fitting (35) (not illustrated).
Applicable to: ALL
412-A-32-40-00-00A-240A-B
ECCN EAR99
31 MAY 2023 Page 00032-1
BHT-412-CRO
ICN-412-A-324000-B-97499-00001-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 1 of 2)
412-A-32-40-00-00A-240A-B
Applicable to: ALL
Page 00032-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-324000-B-97499-00002-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 2 of 2)
Applicable to: ALL
412-A-32-40-00-00A-240A-B
ECCN EAR99
31 MAY 2023 Page 00032-3
BHT-412-CRO
Intentionally blank page
412-A-32-40-00-00A-240A-B
Applicable to: ALL
Page 00032-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Wheel and Tire Assembly - Removal
Procedure
DEFLATE PNEUMATIC TIRE IF INSTALLED PRIOR TO REMOVING NUT (8, Figure 1). IF BOLTS
(6) ARE NOT PROPERLY INSTALLED, AN INFLATED TIRE MAY CAUSE WHEEL HALVES TO
SEPARATE WHEN NUT (8) IS REMOVED.
NOTE
Removal procedure for wheel and tire assembly (5) is given. Removal procedure for wheel and tire
assembly (1) is the same.
1.
Deflate pneumatic tire, if installed.
2.
Remove nut (8).
3.
Remove wheel and tire assembly (5).
Applicable to: ALL
412-A-32-40-00-00A-520A-B
ECCN EAR99
31 MAY 2023 Page 00033-1
BHT-412-CRO
ICN-412-A-324000-B-97499-00001-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 1 of 2)
412-A-32-40-00-00A-520A-B
Applicable to: ALL
Page 00033-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-324000-B-97499-00002-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 2 of 2)
Applicable to: ALL
412-A-32-40-00-00A-520A-B
ECCN EAR99
31 MAY 2023 Page 00033-3
BHT-412-CRO
Intentionally blank page
412-A-32-40-00-00A-520A-B
Applicable to: ALL
Page 00033-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Wheel and Tire Assembly - Installation
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Grease
C-001
AR
Remarks
Procedure
NOTE
Installation procedure for wheel and tire assembly (5, Figure 1) is given. Installation procedure for wheel
and tire assembly (1) is the same.
1.
Apply a bead of grease (C-001) around wheel bearing and apply a film of grease to axle (4).
2.
Position wheel and tire assembly on axle (4). Install sleeve spacer (7), nut (8), and cotter pin (9).
3.
Inflate pneumatic tires to 75 psi (517.1067 kilopascals).
Applicable to: ALL
412-A-32-40-00-00A-720A-B
ECCN EAR99
31 MAY 2023 Page 00034-1
BHT-412-CRO
ICN-412-A-324000-B-97499-00001-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 1 of 2)
412-A-32-40-00-00A-720A-B
Applicable to: ALL
Page 00034-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-324000-B-97499-00002-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 2 of 2)
Applicable to: ALL
412-A-32-40-00-00A-720A-B
ECCN EAR99
31 MAY 2023 Page 00034-3
BHT-412-CRO
Intentionally blank page
412-A-32-40-00-00A-720A-B
Applicable to: ALL
Page 00034-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Tubeless Tire - Removal
Procedure
1.
Remove wheel (412-A-32-40-00-00A-520A-B / 00033).
2.
Remove valve core.
ENSURE THAT TIRE IS DEFLATED PRIOR TO REMOVING BOLTS IN FOLLOWING STEP.
3.
Remove bolts (6, Figure 1).
4.
Separate wheel halves and remove tire.
5.
Remove and discard nitrile wheel seal.
6.
Remove valve stem.
Applicable to: ALL
412-A-32-40-00-01A-520A-B
ECCN EAR99
31 MAY 2023 Page 00035-1
BHT-412-CRO
ICN-412-A-324000-B-97499-00001-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 1 of 2)
412-A-32-40-00-01A-520A-B
Applicable to: ALL
Page 00035-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-324000-B-97499-00002-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 2 of 2)
Applicable to: ALL
412-A-32-40-00-01A-520A-B
ECCN EAR99
31 MAY 2023 Page 00035-3
BHT-412-CRO
Intentionally blank page
412-A-32-40-00-01A-520A-B
Applicable to: ALL
Page 00035-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Tubeless Tire - Installation
Procedure
1.
Install new nitrile wheel seal on inboard machined surface of wheel half.
2.
Install new valve stem.
3.
Place tire on wheel half. Place opposite wheel half on tire and align holes for bolts (6, Figure 1).
4.
Install bolts (6) with steel washer and nut. Torque nuts 125 to 150 inch-pounds (14.12 to 16.95 Nm).
5.
Inflate tire to 75 psi (517.1067 kilopascals).
6.
Install wheel (412-A-32-40-00-00A-720A-B / 00034).
Applicable to: ALL
412-A-32-40-00-01A-720A-B
ECCN EAR99
31 MAY 2023 Page 00036-1
BHT-412-CRO
ICN-412-A-324000-B-97499-00001-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 1 of 2)
412-A-32-40-00-01A-720A-B
Applicable to: ALL
Page 00036-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-324000-B-97499-00002-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 2 of 2)
Applicable to: ALL
412-A-32-40-00-01A-720A-B
ECCN EAR99
31 MAY 2023 Page 00036-3
BHT-412-CRO
Intentionally blank page
412-A-32-40-00-01A-720A-B
Applicable to: ALL
Page 00036-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Tube Type Tire - Removal
Procedure
1.
Remove wheel (412-A-32-40-00-00A-520A-B / 00033).
2.
Remove valve core.
ENSURE THAT TIRE IS DEFLATED PRIOR TO REMOVING BOLTS IN FOLLOWING STEP.
3.
Remove bolts (6, Figure 1).
4.
Separate wheel halves and remove tire and tube.
Applicable to: ALL
412-A-32-40-00-02A-520A-B
ECCN EAR99
31 MAY 2023 Page 00037-1
BHT-412-CRO
ICN-412-A-324000-B-97499-00001-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 1 of 2)
412-A-32-40-00-02A-520A-B
Applicable to: ALL
Page 00037-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-324000-B-97499-00002-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 2 of 2)
Applicable to: ALL
412-A-32-40-00-02A-520A-B
ECCN EAR99
31 MAY 2023 Page 00037-3
BHT-412-CRO
Intentionally blank page
412-A-32-40-00-02A-520A-B
Applicable to: ALL
Page 00037-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Tube Type Tire - Installation
Procedure
1.
Insert tube into tire.
2.
Position tire and tube on wheel half. Position valve stem through hole in wheel.
3.
Place opposite wheel half on tire and align holes for bolts (6, Figure 1).
4.
Install bolts (6) with steel washer and nut. Torque nuts 125 to 150 inch-pounds (14.12 to 16.95 Nm).
5.
Inflate tire to 75 PSI (517.11 kPa).
6.
Install wheel (412-A-32-40-00-00A-720A-B / 00034).
Applicable to: ALL
412-A-32-40-00-02A-720A-B
ECCN EAR99
31 MAY 2023 Page 00038-1
BHT-412-CRO
ICN-412-A-324000-B-97499-00001-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 1 of 2)
412-A-32-40-00-02A-720A-B
Applicable to: ALL
Page 00038-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-324000-B-97499-00002-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 2 of 2)
Applicable to: ALL
412-A-32-40-00-02A-720A-B
ECCN EAR99
31 MAY 2023 Page 00038-3
BHT-412-CRO
Intentionally blank page
412-A-32-40-00-02A-720A-B
Applicable to: ALL
Page 00038-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Ground Handling Wheel Assembly Pump - Removal
Procedure
NOTE
For repair of pump assembly (P/N BU953 or BU953B) and to obtain service kit (P/N JS0953) refer to:
Lowell Corporation at www.Lowellcorp.com.
1.
Remove hose assembly (16, Figure 1) from tee (17). Remove hose assembly (not illustrated) from opposite side
of tee.
2.
Remove two nuts (13), thin steel washers (12) and u-bolt (21). Remove two nuts (15), thin steel washers (14) and
u-bolt (18).
3.
Remove pump (2).
Applicable to: ALL
412-A-32-40-00-03A-520A-B
ECCN EAR99
31 MAY 2023 Page 00039-1
BHT-412-CRO
ICN-412-A-324000-B-97499-00001-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 1 of 2)
412-A-32-40-00-03A-520A-B
Applicable to: ALL
Page 00039-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-324000-B-97499-00002-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 2 of 2)
Applicable to: ALL
412-A-32-40-00-03A-520A-B
ECCN EAR99
31 MAY 2023 Page 00039-3
BHT-412-CRO
Intentionally blank page
412-A-32-40-00-03A-520A-B
Applicable to: ALL
Page 00039-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Ground Handling Wheel Assembly Pump - Installation
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Remarks
Hydraulic fluid
C-002
AR
Hydraulic fluid
C-072
AR
Refer to 412-MM, Chapter 12 for information on
usage and mixing of hydraulic fluid (C-002) and
hydraulic fluid (C-072).
Refer to 412-MM, Chapter 12 for information on
usage and mixing of hydraulic fluid (C-002) and
hydraulic fluid (C-072).
Tape
C-596
AR
Procedure
NOTE
For repair of pump assembly (P/N BU953 or BU953B) and to obtain service kit (P/N JS0953) refer to:
Lowell Corporation at www.Lowellcorp.com.
1.
Apply tape (C-596) to threads of tee (17, Figure 1) and install tee in pump assembly (2).
2.
Position pump assembly (2) on cradle (11). Install u-bolt (21), two thin steel washers (12), and nuts (13). Install u-bolt
(18), two thin steel washers (14), and two nuts (15).
3.
Install hose assembly (16) on tee (17). Install hose assembly (not illustrated) on opposite side of tee.
4.
Fill pump assembly (2) with hydraulic fluid (C-002) or hydraulic fluid (C-072).
5.
Perform functional check of pump assembly (2). Install ground handling wheel assembly on helicopter and raise
helicopter. Check for hydraulic fluid leaks.
Applicable to: ALL
412-A-32-40-00-03A-720A-B
ECCN EAR99
31 MAY 2023 Page 00040-1
BHT-412-CRO
ICN-412-A-324000-B-97499-00001-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 1 of 2)
412-A-32-40-00-03A-720A-B
Applicable to: ALL
Page 00040-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-324000-B-97499-00002-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 2 of 2)
Applicable to: ALL
412-A-32-40-00-03A-720A-B
ECCN EAR99
31 MAY 2023 Page 00040-3
BHT-412-CRO
Intentionally blank page
412-A-32-40-00-03A-720A-B
Applicable to: ALL
Page 00040-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Ground Handling Wheel Assembly Decals - Installation
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Abrasive cloth or paper
C-423
AR
Remarks
Procedure
1.
Remove and discard old decal(s) (19 and/or 20, Figure 1) from pump assembly (2) with sharp plastic scraper.
2.
Clean area where decal(s) will be installed with fine grit abrasive cloth or paper (C-423).
3.
Install new decal(s) (19 and/or 20) on pump assembly (2).
Applicable to: ALL
412-A-32-40-00-04A-720A-B
ECCN EAR99
31 MAY 2023 Page 00041-1
BHT-412-CRO
ICN-412-A-324000-B-97499-00001-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 1 of 2)
412-A-32-40-00-04A-720A-B
Applicable to: ALL
Page 00041-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-324000-B-97499-00002-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 2 of 2)
Applicable to: ALL
412-A-32-40-00-04A-720A-B
ECCN EAR99
31 MAY 2023 Page 00041-3
BHT-412-CRO
Intentionally blank page
412-A-32-40-00-04A-720A-B
Applicable to: ALL
Page 00041-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Ground Handling Wheel Assembly Ram and Trunnion - Removal
Procedure
NOTE
Removal procedure for ram assembly (40, Figure 1) is given. Removal procedure for opposite ram
assembly (not illustrated) is the same.
1.
Remove hose assembly (16).
2.
Remove elbow (39).
3.
Remove lubricating pin (36).
4.
Remove setscrew (45).
5.
Remove clevis (38).
6.
Remove setscrew (42).
7.
Remove ram assembly (40).
8.
Remove opposite ram assembly (not illustrated) in the same manner.
9.
Remove trunnion (41) from cradle assembly (11).
Applicable to: ALL
412-A-32-40-00-05A-520A-B
ECCN EAR99
31 MAY 2023 Page 00042-1
BHT-412-CRO
ICN-412-A-324000-B-97499-00001-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 1 of 2)
412-A-32-40-00-05A-520A-B
Applicable to: ALL
Page 00042-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-324000-B-97499-00002-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 2 of 2)
Applicable to: ALL
412-A-32-40-00-05A-520A-B
ECCN EAR99
31 MAY 2023 Page 00042-3
BHT-412-CRO
Intentionally blank page
412-A-32-40-00-05A-520A-B
Applicable to: ALL
Page 00042-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Ground Handling Wheel Assembly Ram and Trunnion - Installation
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Remarks
Hydraulic fluid
C-002
AR
Hydraulic fluid
C-072
AR
Refer to BHT-412-MM, Chapter 12 for information
on usage and mixing of hydraulic fluid (C-002) and
hydraulic fluid (C-072).
Refer to BHT-412-MM, Chapter 12 for information
on usage and mixing of hydraulic fluid (C-002) and
hydraulic fluid (C-072).
Tape
C-596
AR
Procedure
NOTE
Installation procedure for ram assembly (40, Figure 1) is given. Installation procedure for opposite ram
assembly (not illustrated) is the same.
1.
If not previously accomplished, position trunnion (41) in cradle assembly (11).
2.
Thread ram assembly (40) into trunnion (41) until it bottoms, then back out until port for elbow (39) is outboard.
Install setscrew (42).
3.
Install clevis (38).
4.
Install setscrew (45).
5.
Install lubricating pin (36), thin steel washer (37), thin steel washer (44), and cotter pin (34).
6.
Coat threads of elbow (39) with tape (C-596) and install elbow in ram assembly (40).
7.
Install hose assembly (16).
8.
Fill pump assembly (2) with hydraulic fluid (C-002) or hydraulic fluid (C-072).
9.
Perform functional check of ram assembly (40). Install ground handling wheels on helicopter and raise helicopter.
Check for hydraulic fluid leaks.
Applicable to: ALL
412-A-32-40-00-05A-720A-B
ECCN EAR99
31 MAY 2023 Page 00043-1
BHT-412-CRO
ICN-412-A-324000-B-97499-00001-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 1 of 2)
412-A-32-40-00-05A-720A-B
Applicable to: ALL
Page 00043-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-324000-B-97499-00002-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 2 of 2)
Applicable to: ALL
412-A-32-40-00-05A-720A-B
ECCN EAR99
31 MAY 2023 Page 00043-3
BHT-412-CRO
Intentionally blank page
412-A-32-40-00-05A-720A-B
Applicable to: ALL
Page 00043-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Ground Handling Wheel Assembly Axles - Removal
Procedure
1.
Remove wheel and tire assemblies (1 and 5, Figure 1) (412-A-32-40-00-00A-520A-B / 00033).
2.
Remove lubricating pin (36) and pin (not illustrated) that is opposite lubricating pin (36).
3.
Remove bolts (23 and 46).
4.
Remove axles (4 and 24).
Applicable to: ALL
412-A-32-40-00-06A-520A-B
ECCN EAR99
31 MAY 2023 Page 00044-1
BHT-412-CRO
ICN-412-A-324000-B-97499-00001-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 1 of 2)
412-A-32-40-00-06A-520A-B
Applicable to: ALL
Page 00044-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-324000-B-97499-00002-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 2 of 2)
Applicable to: ALL
412-A-32-40-00-06A-520A-B
ECCN EAR99
31 MAY 2023 Page 00044-3
BHT-412-CRO
Intentionally blank page
412-A-32-40-00-06A-520A-B
Applicable to: ALL
Page 00044-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Ground Handling Wheel Assembly Axles - Installation
Procedure
NOTE
If axles (4 and 24, Figure 1) have not been drilled for bolts (23 and 46), accomplish Step 1. through
Step 8.. If axles have been drilled, accomplish Step 1. then proceed to Step 9..
1.
Operate pump assembly (2) to fully extend ram assembly (40) and opposite ram assembly (not illustrated).
2.
Position axle (24) in cradle assembly (11) from right side. Position axle (4) in cradle assembly (11) from left side with
sleeve spacer (31) positioned on axle with larger dimension from bolt hole to edge of sleeve spacer facing inboard.
3.
Loosen setscrew (45) and adjust clevis (38) to hold axle (4) at 1.98 inches (50.292 mm) dimension as shown in
Figure 2, View B.
4.
Adjust setscrew (45, Figure 1) to contact axle (4) and allow lubricating pin (36) to be installed. Install lubricating pin
(36), thin steel washers (37 and 44), and cotter pin (34).
5.
Adjust clevis at base of axle (24) in same manner outlined in Step 3. and Step 4..
6.
Position axles (4 and 24) to 5.214 inches (132.4356 mm) dimensions as shown on Figure 2, View A.
7.
Line drill axles (4 and 24, Figure 1) for bolts (23 and 46). Make holes 0.316 to 0.322 inch (8.03 to 8.18 mm) in diameter.
8.
Remove axles (4 and 24) and remove chips from drilling operation, then position axles on cradle in original position.
9.
Align holes in sleeve spacer (31) and axles (4 and 24). Install bolt (46), thin steel washers (32 and 44), and nut (33).
Install bolt (23), thin steel washers (22 and 25), and nut (26).
10.
Install wheel and tire assemblies (1 and 5) (412-A-32-40-00-00A-720A-B / 00034).
11.
Lubricate ground handling wheels (412-A-32-40-00-00A-240A-B / 00032).
12.
Perform functional check of ground handling wheels (412-A-32-40-00-00A-280A-B / 00031).
Applicable to: ALL
412-A-32-40-00-06A-720A-B
ECCN EAR99
31 MAY 2023 Page 00045-1
BHT-412-CRO
ICN-412-A-324000-B-97499-00001-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 1 of 2)
412-A-32-40-00-06A-720A-B
Applicable to: ALL
Page 00045-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-324000-B-97499-00002-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 2 of 2)
Applicable to: ALL
412-A-32-40-00-06A-720A-B
ECCN EAR99
31 MAY 2023 Page 00045-3
BHT-412-CRO
ICN-412-A-324000-B-97499-00003-A-001-01
Figure 2. Ground Handling Wheels Axle Installation (Sheet 1 of 1)
412-A-32-40-00-06A-720A-B
Applicable to: ALL
Page 00045-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Ground Handling Wheel Assembly Bushings - Removal
Procedure
1.
Remove wheels, pump, axles and other components as necessary to gain access to bushings (47, 48, 49,
and 51, Figure 1). Refer to 412-A-32-40-00-00A-520A-B / 00033, 412-A-32-40-00-03A-520A-B / 00039, and
412-A-32-40-00-06A-520A-B / 00044. If bushing (51) must be replaced, remove spring pin (50) and pin (10).
2.
Heat cradle assembly (11) with heat lamp in area where bushing is to be removed.
3.
Press or pull bushings (47, 48, 49 or 51) from cradle assembly (11).
Applicable to: ALL
412-A-32-40-00-07A-520A-B
ECCN EAR99
31 MAY 2023 Page 00046-1
BHT-412-CRO
ICN-412-A-324000-B-97499-00001-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 1 of 2)
412-A-32-40-00-07A-520A-B
Applicable to: ALL
Page 00046-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-324000-B-97499-00002-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 2 of 2)
Applicable to: ALL
412-A-32-40-00-07A-520A-B
ECCN EAR99
31 MAY 2023 Page 00046-3
BHT-412-CRO
Intentionally blank page
412-A-32-40-00-07A-520A-B
Applicable to: ALL
Page 00046-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Ground Handling Wheel Assembly Bushings - Installation
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Zinc chromate primer
C-201
AR
Remarks
Procedure
1.
Clean bore in cradle assembly (11, Figure 1) where bushings (47, 48, 49, or 51) will be installed.
2.
Coat bushings with (47, 48, 49, or 51) zinc chromate primer (C-201) and press into cradle assembly (11) while primer
is wet. Outboard faces of bushings (48, 49, and 51) must be flush with surface of cradle. Bushing (47) must be flush
with cradle surface at both ends. If bushings protrudes past cradle surface, face off bushing.
3.
Line ream bushings (47, 48 and 49) to 0.5000 to 0.5100 inch (12.700 to 12.954 mm). Check release pin (3) from
slip fit in bushings.
4.
Ream bushing (51) 0.4995 to 0.5005 inch (12.687 to 12.713 mm). Position pin (10) in bushing (51) with bevel
facing down. Install spring pin (50).
5.
Install wheels, axles, pump and other components that were removed to expose bushings. Refer to
412-A-32-40-00-00A-720A-B / 00034, 412-A-32-40-00-03A-720A-B / 00040, and 412-A-32-40-00-06A-720A-B /
00045.
Applicable to: ALL
412-A-32-40-00-07A-720A-B
ECCN EAR99
31 MAY 2023 Page 00047-1
BHT-412-CRO
ICN-412-A-324000-B-97499-00001-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 1 of 2)
412-A-32-40-00-07A-720A-B
Applicable to: ALL
Page 00047-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-324000-B-97499-00002-A-001-01
Figure 1. Ground Handling Wheels Assembly (Sheet 2 of 2)
Applicable to: ALL
412-A-32-40-00-07A-720A-B
ECCN EAR99
31 MAY 2023 Page 00047-3
BHT-412-CRO
Intentionally blank page
412-A-32-40-00-07A-720A-B
Applicable to: ALL
Page 00047-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
CHAPTER 62
MAIN ROTOR
COMPONENT REPAIR AND OVERHAUL MANUAL
Applicable to: ALL
412-A-62-00-00-00A-009A-A
ECCN EAR99
28 OCT 2024 Page 00048-1
BHT-412-CRO
Intentionally blank page
412-A-62-00-00-00A-009A-A
Applicable to: ALL
Page 00048-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
List of Effective Data Modules
The listed documents are included in issue 003, dated 2024-10-28, of this publication.
C = Changed data module, N = New data module
Document title
Data module code / Seq number
Issue date
Applicable
to
Main Rotor Hub - Configuration
DMC-412-A-62-00-00-00B-020A-B /
00049
2023-05-31
ALL
Main Rotor Hub - Disassembly
DMC-412-A-62-20-00-00A-530A-B /
00050
2023-05-31
ALL
Main Rotor Hub - Cleaning
DMC-412-A-62-20-00-00A-258A-B /
00051
2023-05-31
ALL
Main Rotor Hub - Inspection
DMC-412-A-62-20-00-00A-280A-B /
00052
2023-05-31
ALL
Main Rotor Hub - Conditional Inspection
DMC-412-A-62-20-00-00A-284A-B /
00053
2023-05-31
ALL
Main Rotor Hub - Normal Inspection
DMC-412-A-62-20-00-00A-280B-B /
00054
2023-11-14
ALL
Main Rotor Hub - Non-destructive Inspection
DMC-412-A-62-20-00-00A-353A-B /
00055
2023-05-31
ALL
Main Rotor Hub - Repair
DMC-412-A-62-20-00-00A-685A-B /
00056
2023-05-31
ALL
Main Rotor Hub - Assembly
DMC-412-A-62-20-00-00A-710A-B /
00057
2023-05-31
ALL
Main Rotor Blade - Cleaning
DMC-412-A-62-10-00-00A-258A-B /
00058
2023-05-31
ALL
Main Rotor Blade - Conditional Inspection
DMC-412-A-62-10-00-00A-284A-B /
00059
2023-05-31
ALL
Main Rotor Blade - Normal Inspection
DMC-412-A-62-10-00-00A-280B-B /
00060
2023-05-31
ALL
Main Rotor Blade - Repair
DMC-412-A-62-10-00-00A-685A-B /
00061
2023-05-31
ALL
Main Rotor Blade - Insert (MS124695)
Replacement
DMC-412-A-62-10-00-00A-921A-B /
00062
2023-05-31
ALL
Main Rotor Blade - Erosion Shield Replacement
DMC-412-A-62-10-00-05A-921A-B /
00063
2023-05-31
ALL
Main Rotor Hub and Sleeve Assembly
(412-010-401-105, -107, -109, -111, -113, -115,
and -117) - Disassembly
DMC-412-A-62-20-00-02A-530A-B /
00064
2023-11-14
ALL
Main Rotor Hub and Sleeve Assembly
(412-010-401-105, -107, -109, -111, -113, -115,
and -117) - Cleaning
DMC-412-A-62-20-00-02A-258A-B /
00065
2023-11-14
ALL
Main Rotor Hub and Sleeve Assembly
(412-010-401-105, -107, -109, -111, -113, -115,
and -117) - Inspection
DMC-412-A-62-20-00-02A-280A-B /
00066
2023-05-31
ALL
Main Rotor Hub and Sleeve Assembly
(412-010-401-105, -107, -109, -111, -113, -115,
and -117) - Conditional Inspection
DMC-412-A-62-20-00-02A-284A-B /
00067
2023-05-31
ALL
Main Rotor Hub and Sleeve Assembly
(412-010-401-105, -107, -109, -111, -113, -115,
and -117) - Normal Inspection
DMC-412-A-62-20-00-02A-280B-B /
00068
2023-11-14
ALL
Main Rotor Hub and Sleeve Assembly
(412-010-401-105, -107, -109, -111, -113, -115,
and -117) - Non-destructive Inspection
DMC-412-A-62-20-00-02A-353A-B /
00069
C 2024-10-28
ALL
Applicable to: ALL
ECCN EAR99
412-A-62-00-00-00A-00SA-A
28 OCT 2024 Page 1
BHT-412-CRO
Document title
Data module code / Seq number
Issue date
Applicable
to
Main Rotor Hub and Sleeve Assembly
(412-010-401-105, -107, -109, -111, -113, -115,
and -117) - Repair
DMC-412-A-62-20-00-02A-685B-B /
00070
2023-11-14
ALL
Main Rotor Hub and Sleeve Assembly
(412-010-401-105, -107, -109, -111, -113, -115,
and -117) - Assembly
DMC-412-A-62-20-00-02A-710A-B /
00071
2023-11-14
ALL
Main Rotor Controls Pitch Link - Disassembly
DMC-412-A-62-30-00-00A-530A-B /
00072
2023-05-31
ALL
Main Rotor Controls Pitch Link - Cleaning
DMC-412-A-62-30-00-00A-258A-B /
00073
2023-05-31
ALL
Main Rotor Controls Pitch Link - Inspection
DMC-412-A-62-30-00-00A-280A-B /
00074
2023-05-31
ALL
Main Rotor Controls Pitch Link - Non-destructive
Inspection
DMC-412-A-62-30-00-00A-353A-B /
00075
2023-05-31
ALL
Main Rotor Controls Pitch Link - Repair
DMC-412-A-62-30-00-00A-685A-B /
00076
2023-05-31
ALL
Main Rotor Controls Pitch Link - Assembly
DMC-412-A-62-30-00-00A-710A-B /
00077
2023-05-31
ALL
Main Rotor Controls Swashplate and Support Disassembly
DMC-412-A-62-30-00-05A-530A-B /
00078
2023-05-31
ALL
Main Rotor Controls Swashplate and Support Cleaning
DMC-412-A-62-30-00-05A-258A-B /
00079
2023-05-31
ALL
Main Rotor Controls Swashplate and Support Inspection
DMC-412-A-62-30-00-05A-280A-B /
00080
2023-05-31
ALL
Main Rotor Controls Swashplate and Support Conditional Inspection
DMC-412-A-62-30-00-05A-284A-B /
00081
2023-05-31
ALL
Main Rotor Controls Swashplate and Support Normal Inspection
DMC-412-A-62-30-00-05A-280B-B /
00082
2023-05-31
ALL
Main Rotor Controls Swashplate and Support Non-destructive Inspection
DMC-412-A-62-30-00-05A-353A-B /
00083
2023-05-31
ALL
Main Rotor Controls Swashplate and Support Repair
DMC-412-A-62-30-00-05A-685A-B /
00084
2023-05-31
ALL
Main Rotor Controls Swashplate and Support Assembly
DMC-412-A-62-30-00-05A-710A-B /
00085
2023-05-31
ALL
Main Rotor Controls Collective Lever
(412-010-408-101) - Disassembly
DMC-412-A-62-30-00-03A-530A-B /
00086
2023-05-31
ALL
Main Rotor Controls Collective Lever
(412-010-408-101) - Cleaning
DMC-412-A-62-30-00-03A-258A-B /
00087
2023-05-31
ALL
Main Rotor Controls Collective Lever
(412-010-408-101) - Inspection
DMC-412-A-62-30-00-03A-280A-B /
00088
2023-05-31
ALL
Main Rotor Controls Collective Lever
(412-010-408-101) - Non-destructive Inspection
DMC-412-A-62-30-00-03A-353A-B /
00089
2023-05-31
ALL
Main Rotor Controls Collective Lever
(412-010-408-101) - Repair
DMC-412-A-62-30-00-03A-685A-B /
00090
2023-05-31
ALL
Main Rotor Controls Collective Lever
(412-010-408-101) - Assembly
DMC-412-A-62-30-00-03A-710A-B /
00091
2023-05-31
ALL
Main Rotor Controls Collective Lever
(412-010-464-101) - Disassembly
DMC-412-A-62-30-00-03B-530A-B /
00092
2023-05-31
ALL
Main Rotor Controls Collective Lever
(412-010-464-101) - Cleaning
DMC-412-A-62-30-00-03B-258A-B /
00093
2023-05-31
ALL
Main Rotor Controls Collective Lever
(412-010-464-101) - Inspections
DMC-412-A-62-30-00-03B-280A-B /
00094
2023-05-31
ALL
412-A-62-00-00-00A-00SA-A
Page 2 28 OCT 2024
Applicable to: ALL
ECCN EAR99
BHT-412-CRO
Document title
Data module code / Seq number
Issue date
Applicable
to
Main Rotor Controls Collective Lever
(412-010-464-101) - Non-destructive Inspection
DMC-412-A-62-30-00-03B-353A-B /
00095
2023-05-31
ALL
Main Rotor Controls Collective Lever
(412-010-464-101) - Repair
DMC-412-A-62-30-00-03B-685A-B /
00096
2023-05-31
ALL
Main Rotor Controls Collective Lever
(412-010-464-101) - Assembly
DMC-412-A-62-30-00-03B-710A-B /
00097
2023-05-31
ALL
Applicable to: ALL
ECCN EAR99
412-A-62-00-00-00A-00SA-A
28 OCT 2024 Page 3
BHT-412-CRO
Intentionally blank page
412-A-62-00-00-00A-00SA-A
Page 4 28 OCT 2024
Applicable to: ALL
ECCN EAR99
BHT-412-CRO
Main Rotor Hub - Configuration
The Model 412 helicopters were delivered with the main rotor hub assembly configurations shown in Table 2.
Use the information in Table 3 and Table 4, as applicable, to verify the configuration or to upgrade a main rotor hub assembly.
The components listed below an assembly dash number are included in that specified configuration.
NOTE
Standard hardware common to all configuration is not included in Table 3, Table 4, Table 5 and Table 6,
refer to the applicable Illustrated Parts Breakdown (IPB) .
Any noted main rotor hub assembly can be upgraded to a later configuration. When an assembly is upgraded, all applicable
Alert Service Bulletins (ASB) and Technical Bulletins (TB) referenced in Table 3 and Table 4 must be incorporated.
Identify the upgraded main rotor assembly with the correct configuration dash number as follows:
-
Use a vibrating tool to mark the data plate of the main rotor hub assembly. The depth of the vibroetch must not exceed
0.005 inch (0.13 mm).
NOTE
The suffix “FM” indicates Field Modified.
Example: 412-010-100-195 -217FM
-
Amend the component historical service records with the new part number. The serial number of a field modified part will
not be altered or changed.
NOTE
Table 3 and Table 4, as applicable, lists all the main rotor hub assembly configurations.
A partial upgrade does not qualify for a data plate or Historical Service Record (HSR) identification change.
Use the information in Table 5, as applicable, to verify the configuration of the yoke and spindle assembly. The components
listed below an assembly dash number are included in that specified configuration.
Use the information in Table 6, as applicable, to verify the configuration of the arm and bearing assembly. The components
listed below an assembly dash number are included in that specified configuration.
Following an upgrade of the main rotor hub assembly, amend the main rotor hub assembly HSR to show:
- The new configuration Part Number (P/N) .
- The new component inspection intervals, as applicable.
- The new retirement life of the main rotor hub assembly sub-components, as applicable.
Table 2. Main Rotor Hub Assembly Versus Helicopter Serial Number
MAST ASSEMBLY PART NUMBER
HELICOPTER SERIAL NUMBER
412-010-100-139
33001 through 33108
412-010-100-145
33109 through 33110
412-010-100-159
33111 through 33115
33116 through 33199
412-010-100-151
34001 through 34015
33200 through 33213
412-010-100-171
36001 through 36014
36015 through 36037
412-010-100-175
34016 through 34024
412-010-100-193
36038 through 36049
412-010-100-181
36050 through 36061
412-010-100-201
36062 through 36068
Applicable to: ALL
412-A-62-00-00-00B-020A-B
ECCN EAR99
31 MAY 2023 Page 00049-1
BHT-412-CRO
Table 2. Main Rotor Hub Assembly Versus Helicopter Serial Number (continued)
MAST ASSEMBLY PART NUMBER
HELICOPTER SERIAL NUMBER
36069 through 36119
412-010-100-195
34025 through 34036
46400 through 46424
36120 through 36201
412-010-100-209
46425 through 46499
36202 through 36384
412-010-100-217 (1) (2)
Spare (46400 through 46499)
412-010-100-133 (3)
36385 through 36677
412-010-100-233 (2)
Spare (46400 through 46499)
36678 and subsequent
412-010-100-237 (3)
37002 and subsequent
412-010-100-239 (1)
Spare replacement
412-010-100-241 (2)
Spare (46400 through 46499)
NOTES:
1
33001 through 33213, 34001 through 34036 and 36001 through 36384, 412-010-100-217 spares replacement is
412-010-100-239.
2
46400 through 46499 only, 412-010-100-217 and 412-010-100-233 spares replacement is 412-010-100-241.
3
412-010-100-133 spares replacement is 412-010-100-237.
Table 3. Main Rotor Hub Assembly — Configuration
NPOAMRET
NQNCTULY
MABTUERR
E
MAIN ROTOR HUB ASSEMBLY 412-010-100
-193 (1)
-181
-201
-195 (2)
2
0-0
6
5BHo8
0l8t
0
6
6
X
X
X
X
4Y1o2k0e2
1a0n1d
0s-
X
412-A-62-00-00-00B-020A-B
Applicable to: ALL
Page 00049-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Table 3. Main Rotor Hub Assembly — Configuration (continued)
NPOAMRET
NQNCTULY
MABTEUR
RE
MAIN ROTOR HUB ASSEMBLY 412-010-100
-193 (1)
-181
-201
-195 (2)
X
X
X
pindl0e
1a7s7sembly
Yoke
a4n1d
2s0p1i0n2
1d0l0e
1a8s3sembly
Y4o1ke
20a1nd
02
1sp0
i02n0d7le
aApplicable to: ALL
412-A-62-00-00-00B-020A-B
ECCN EAR99
31 MAY 2023 Page 00049-3
BHT-412-CRO
Table 3. Main Rotor Hub Assembly — Configuration (continued)
NPOAMRET
NQNCTULY
MABTEUR
RE
MAIN ROTOR HUB ASSEMBLY 412-010-100
-193 (1)
-181
-201
X
X
X
-195 (2)
ssembly
Bla4
d1
e
2b0
o1
l0t4
1
a2
s4s1
e0
m5
bly
Bla4
d1
e
2b0
o1
l0t4
1
a2
s4s1
e0
m9
bly
X
412-A-62-00-00-00B-020A-B
Applicable to: ALL
Page 00049-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Table 3. Main Rotor Hub Assembly — Configuration (continued)
NPOAMRET
NQNCTULY
MABTEUR
RE
MAIN ROTOR HUB ASSEMBLY 412-010-100
-193 (1)
-181
-201
-195 (2)
Exp.
b4
l1
a2d0
e
1
b0o4
1
l3
t
7a1
s0
s3
embly
X
X
X
X
4
1
2D0r1i0v8
1e
6p6i1n
0
1
X
X
X
X
4S1p2l-1
0i1n0e-
X
X
Applicable to: ALL
412-A-62-00-00-00B-020A-B
ECCN EAR99
31 MAY 2023 Page 00049-5
BHT-412-CRO
Table 3. Main Rotor Hub Assembly — Configuration (continued)
NPOAMRET
NQNCTULY
MABTEUR
RE
MAIN ROTOR HUB ASSEMBLY 412-010-100
-193 (1)
-181
-201
-195 (2)
X
X
X
X
d
pla1t7e
7a1s0s5embly
Spli4n1e2d
0p1l0a1
1t7e
7a1s1s7embly
U4
p1
p2e0
r
1
c0o1
1
n8
e
6s1
e0
a3
t
X
X
412-A-62-00-00-00B-020A-B
Applicable to: ALL
Page 00049-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Table 3. Main Rotor Hub Assembly — Configuration (continued)
NPOAMRET
NQNCTULY
MABTEUR
RE
MAIN ROTOR HUB ASSEMBLY 412-010-100
-193 (1)
-181
-201
-195 (2)
Arm
an4
d
1
b2e0
a1
r0i-4
2
n1
g
6a1
s0
s5
embly
X
X
X
X
Arm
an4
d
1
b2e0
a1
r0i-4
2
n1
g
6a1
s0
s7
embly
X
X
X
X
Applicable to: ALL
412-A-62-00-00-00B-020A-B
ECCN EAR99
31 MAY 2023 Page 00049-7
BHT-412-CRO
Table 3. Main Rotor Hub Assembly — Configuration (continued)
NPOAMRET
NQNCTULY
MABTEUR
RE
MAIN ROTOR HUB ASSEMBLY 412-010-100
-193 (1)
-181
4
1
2V0e1n0t
4
2p7l2u1g
0
1
L4
o1
w2e0
r
1
c8o1
0
n5
e
6s1
e0
a5
t
X
X
ANP8l4
1u4-4
g
L
X
X
-201
-195 (2)
X
X
X
X
NOTES:
1
For configurations prior to 412-010-100-193 refer to TB 412-92-104.
2
For main rotor hub assembly 412-010-100-195 and -209, if the intent of ASB 412-98-92 (ASB 412CF-98-04), ASB 412-98-93 (ASB 412C
412-08-128 (ASB 412CF-08-35) and TB 412-03-190 (TB 412CF-03-68) have been accomplished, they are at the same configuration as
assembly 412-010-100-217. Refer to Table 4.
3
Refer to Table 5 for yoke and spindle assembly configurations.
4
Blade bolt assembly 412-010-124-105 and plug AN814-4L replaced by blade bolt assembly 412-010-124-109 and vent plug 412-010-272
ASB 412-93-73.
5
If blade folding is not required, accomplish TB 412-92-103 (TB 412CF-04-73) to replace expandable blade bolt assemblies 412-010-137bolt assemblies 412-010-124-109.
6
If Increased Gross Weight kit 412-706-140-101 (BHT-412-SI-95) and Slope Landing Retrofit kit 412-704-012-111 (BHT-412-SI-62) are em
pin 412-010-166-101 becomes 412-010-166-103FM. Refer to Table 4.
7
Splined plate 412-010-177-105 usable on S/N 33001 through 33213, S/N 34001 through 34024 and S/N 36001 through 36019. Refer to A
8
Used in post TB 412-92-104 configurations.
412-A-62-00-00-00B-020A-B
Applicable to: ALL
Page 00049-8 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Table 3. Main Rotor Hub Assembly — Configuration (continued)
NPOAMRET
NQNCTULY
MABTEUR
RE
MAIN ROTOR HUB ASSEMBLY 412-010-100
-193 (1)
-181
-195 (2)
-201
9
Splined plate 412-010-177-117 usable on S/N 34025 through 34036, S/N 36020 and subsequent and S/N 37002 and subsequent.
10
If Increased Gross Weight kit 412-706-140-101 (BHT-412-SI-95) and Slope Landing Retrofit kit 412-704-012-111 (BHT-412-SI-62)
plate assembly 412-010-177-117 becomes 412-010-177-121FM. Refer to Table 4.
11
If Increased Gross Weight kit 412-706-140-101 (BHT-412-SI-95) and Slope Landing Retrofit kit 412-704-012-111 (BHT-412-SI-62
cone seat 412-010-186-103 becomes 412-010-186-107FM. Refer to Table 4.
12
Arm and bearing assembly 412-010-216-105 replaced by arm and bearing assembly 412-010-216-109. Refer to Table 6.
13
Arm and bearing assembly 412-010-216-107 replaced by arm and bearing assembly 412-010-216-111. Refer to Table 6.
14
Refer to Table 6 for arm and bearing assembly configurations.
15
If Increased Gross Weight kit 412-706-140-101 (BHT-412-SI-95) and Slope Landing Retrofit kit 412-704-012-111 (BHT-412-SI-62)
seat 412-018-056-105 becomes 412-018-056-109FM. Refer to Table 3.
Table 4. Main Rotor Hub Assembly — Configuration
PART
NUMBER
NOMENCLATURE
QTY
2Bolt
0-0
6
5
H0
8
0
6
6
8
4Yoke and spindle assembly
1
20
1
01
0
01
8
3
2
-217 (1) (2)
X
-133 (1) (2)
X
Applicable to: ALL
412-A-62-00-00-00B-020A-B
ECCN EAR99
31 MAY 2023 Page 00049-9
BHT-412-CRO
Table 4. Main Rotor Hub Assembly — Configuration (continued)
4Yoke and spindle assembly
1
20
1
01
0
02
0
7
2
4Yoke and spindle assembly
1
20
1
01
0
02
1
5
2
4Yoke and spindle assembly
1
20
1
01
0
02
3
1
2
4Blade bolt assembly
1
20
1
01
2
41
0
9
4
4Blade bolt assembly
1
20
1
01
2
41
0
9
8
X
X
X
X
X
X
412-A-62-00-00-00B-020A-B
Applicable to: ALL
Page 00049-10 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Table 4. Main Rotor Hub Assembly — Configuration (continued)
4Exp. blade bolt assembly
1
20
1
01
3
71
0
3
4
X
X
4Drive pin
1
20
1
01
6
61
0
1
8
X
X
4Drive pin
1
20
1
01
6
61
0
3
A/R
4Splined plate assembly
1
20
1
01
7
71
1
7
1
X
X
4Splined plate assembly
1
20
1
01
7
71
2
1
A/R
Applicable to: ALL
412-A-62-00-00-00B-020A-B
ECCN EAR99
31 MAY 2023 Page 00049-11
X
BHT-412-CRO
Table 4. Main Rotor Hub Assembly — Configuration (continued)
4Upper cone seat
1
20
1
01
8
61
0
3
1
X
X
4Upper cone seat
1
20
1
01
8
61
0
7
A/R
4Arm and bearing assembly
1
20
1
02
1
61
0
5
4
X
X
X
4Arm and bearing assembly
1
20
1
02
1
61
0
7
4
X
X
X
4Arm and bearing assembly
1
20
1
02
1
61
0
9
4
412-A-62-00-00-00B-020A-B
Applicable to: ALL
Page 00049-12 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Table 4. Main Rotor Hub Assembly — Configuration (continued)
4Arm and bearing assembly
1
20
1
02
1
61
1
1
4
4Vent plug
1
20
1
02
7
21
0
1
4
4Vent plug
1
20
1
02
7
21
0
1
8
4Lower cone seat
1
20
1
80
5
61
0
5
1
4Lower cone seat
1
20
1
80
5
61
0
9
A/R
X
X
X
X
X
Applicable to: ALL
412-A-62-00-00-00B-020A-B
ECCN EAR99
31 MAY 2023 Page 00049-13
X
BHT-412-CRO
Table 4. Main Rotor Hub Assembly — Configuration (continued)
MBolt
S2
1
2
5
0
H0
8
0
6
6
8
X
NOTES:
1
Main rotor hub assembly 412-010-100-133 (S/N 36385 through 36677) spares replacement is main rotor hub assembly 412-010-100-237
main rotor hub assembly 412-010-100-239.
2
Main rotor hub assembly 412-010-100-217 (S/N 46400 through 46499 only) and main rotor hub assembly 412-010-100-233 spares repla
3
Refer to Table 5 for yoke and spindle assembly configurations.
4
If blade folding is desired, kit 412-706-087-101 can be installed as per BHT-412-SI-52.
5
If blade folding is not required, accomplish TB 412-92-103 (TB 412CF-04-73) to replace expandable blade bolt assemblies 412-010-137-
6
If Increased Gross Weight kit 412-706-140-101 (BHT-412-SI-95) and Slope Landing Retrofit kit 412-704-012-111 (BHT-412-SI-62) are em
7
Splined plate 412-010-177-117 usable on S/N 34025 through 34036, S/N 36020 and subsequent, 46400 through 46499 and S/N 37002 a
8
If increased Gross Weight kit 412-706-140-101 (BHT-412-SI-95) and Slope Landing Retrofit kit 412-704-012-111 (BHT-412-SI-62) are em
9
If Increased Gross Weight kit 412-706-140-101 (BHT-412-SI-95) and Slope Landing Retrofit kit 412-704-012-111 (BHT-412-SI-62) are em
10
Arm and bearing assembly 412-010-216-105 replaced by arm and bearing assembly 412-010-216-109. Refer to Table 6.
11
Refer to Table 6 for arm and bearing assembly configurations.
12
Arm and bearing assembly 412-010-216-107 replaced by arm and bearing assembly 412-010-216-111. Refer to Table 6.
13
If Increased Gross Weight kit 412-706-140-101 (BHT-412-SI-95) and Slope Landing Retrofit kit 412-704-012-111 (BHT-412-SI-62) are em
Table 5. Yoke and Spindle Assembly — Configuration
YOKE AND SPINDLE ASSEMBLY 412-010-100
PART
NUMBER
NOMENCLATURE
412-010101-127
Yoke
assembly
1
412-010101-129
Yoke
assembly
1
412-010101-137
Yoke
assembly
1
412-010101-137
Yoke
assembly
A/R
412-010101-139
Yoke
assembly
1
412-010101-139
Yoke
assembly
A/R
412-010106-101
Pivot
bearing
2
X
X
X
X
X
412-010111-103
Fitting
2
X
X
X
X
X
QTY
-177 (1) (2)
X
-183 (1)
X
-207 (1)
-215 (1)
-231 (1)
NOTES
(3) (4) (5) (6)
X
(5) (6) (7)
X
X
(5) (6) (7)
(5) (6)
X
(7)
(7)
X
(8)
412-A-62-00-00-00B-020A-B
Applicable to: ALL
Page 00049-14 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Table 5. Yoke and Spindle Assembly — Configuration (continued)
412-010144-103
Slip bushing 8
X
X
X
X
412-010145-105
Damper
yoke set
1
X
412-010148-103
Shim
4
X
X
X
X
X
412-010149-111
Pitch horn
assembly
2
X
X
X
X
X
(10)
412-010170-105
Bridge
assembly
(lower)
2
X
X
X
X
X
(11)
412-010180-103
Pin
16
X
X
X
X
X
(10)
412-010185-109
Bridge
assembly
(upper)
2
X
X
X
X
X
(12)
412-010190-103
Spindle and 2
damper
bearing
assembly
X
412-010190-105
Spindle and 2
damper
bearing
assembly
X
X
X
X
412-310146-103
Damper
yoke set
1
X
X
X
X
CEREX
3603-23
Non-woven
fabric
A/R
NAS6605-4
0
Bolt
8
(2) (9)
(2)
(13) (14)
(15)
X
X
X
X
X
NOTES:
1
Quantity two (2) yoke and spindle assemblies per main rotor hub assembly.
2
For upgrade refer to TB 412-00-168.
3
Refer to ASB 412-98-93 (ASB 412CF-98-5) for possible imposition of a 500 hour penalty.
4
Yoke assembly 412-010-101-127 spares replacement is yoke assembly 412-010-101-129.
5
If Slope Landing Retrofit kit 412-704-012-101 (BHT-412-SI-62) is embodied, refer to ASB 412-08-128, yoke assembly
412-010-101-127/-129 becomes yoke assembly 412-010-101-137FM.
6
S/N 46400 through 46499 only, refer to 412CF-08-35, yoke assembly 412-010-101-127/-129 becomes yoke assembly
412-010-101-137FM.
7
If Increased Gross Weight kit 412-706-140-101 (BHT-412-SI-95) and Slope Landing Retrofit kit 412-704-012-111
(BHT-412-SI-62) are embodied, the yoke assembly 412-010-101-129 or -137 becomes 412-010-101-139FM.
8
Fitting 412-010-111-101 may be used as an alternate for fitting 412-010-111-103.
9
Damper yoke set 412-010-145-105 (four pieces each) replaces two damper yoke sets 412-010-145-103 (two pieces
each) used on S/N 33001 through 33213 and S/N 36001 through 36049. When using damper set 412-010-145-105,
always replace complete damper yoke set even when only one requires replacement.
10
Pitch horn assembly 412-010-149-111 and pins 412-010-180-103 replace pitch horn assembly 412-010- 149-105 and
pins 412-010-180-101 as a unit. Do not use pins 412-010-180-101 with pitch horn assembly 412-010-149-111.
11
Damper bridge assembly (lower) 412-010-170-105 is the spare parts replacement for damper bridge assembly
412-018-068-101 and 412-010-170-101. Damper bridge assembly 412-018-068-105 may be used as an alternate for
damper bridge assembly 412-010-170-105.
Applicable to: ALL
412-A-62-00-00-00B-020A-B
ECCN EAR99
31 MAY 2023 Page 00049-15
BHT-412-CRO
Table 5. Yoke and Spindle Assembly — Configuration (continued)
12
Damper bridge assembly (upper) 412-010-185-109 is the spare parts replacement for damper bridge assembly
412-010-183-105. Damper bridge assembly 412-010-183-109 may be used as an alternate for damper bridge
assembly 412-010-185-109.
13
Always replace complete yoke sets even when only one requires replacement. Blue and red blades share one yoke set
and the green and orange blades share one yoke set. One damper yoke set consists of four dampers.
14
Use damper yoke set 412-310-146-103 as spare parts replacement for damper yoke set 412-310-146-101 used on
S/N 36050 to 36086 only.
15
For CEREX 3603-23 non-woven fabric (C-505) order 2620-00051-00.
Table 6. Arm and Bearing Assembly — Configuration
PART
NUMBER
NOMENCLATURE
ARM AND BEARING ASSEMBLY412-010-216
QTY
-105 (1)
-107 (2)
-109 (1)
-111 (2)
120008C43-27
Shim
1
X
X
X
X
140-00733S28C5
Washer
2
X
X
X
X
412-010-214101
Bracket
assembly
1
X
412-010-215101
Bracket
assembly
1
412-010-217101
Arm assembly 1
X
X
412-010-218101
Weight
1
X
X
X
X
412-010-219101
Inner Race
1
X
X
X
X
412-010-220101
Retainer
assembly
2
X
X
X
X
412-010-221103
Bushing
1
X
X
X
X
412-010-223101
Washer
2
X
X
X
X
412-010-225101
Shim
1
X
X
412-010-226101
Bearing
2
X
X
412-010-263101
Arm
1
NOTES
(3)
X
X
(4)
X
(5)
(5)
X
X
(6)
X
X
(5)
NOTES:
1
Arm and bearing assembly 412-010-216-105/-109 installed on Leading Edge (LE) of yoke assembly.
2
Arm and bearing assembly 412-010-216-107/-111 installed on Trailing Edge (TE) of yoke assembly.
3
Bracket assembly 412-010-214-101 can be replaced by 412-010-264-105, in Next Higher Assembly (NHA)
412-010-216-105 only, provided it is serviceable in accordance with ASB 412-12-149 (ASB 412CF-12-48). Use bracket
assembly 412-010-264-111 as the spare replacement.
4
Bracket assembly 412-010-215-101 can be replaced by 412-010-264-101, in NHA 412-010-216-107 only, provided
it is serviceable in accordance with ASB 412-12-149 (ASB 412CF-12-48). Use bracket assembly 412-010-264-109
as the spare replacement.
5
Arm assembly 412-010-217-101 and Shim 412-010-225-101 replaced as a unit by arm 412-010-263-101.
6
Bearing 412-010-226-101 replaces bearing 412-010-451-101.
412-A-62-00-00-00B-020A-B
Applicable to: ALL
Page 00049-16 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Hub - Disassembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Buildup Bench Assembly
T101263-101
1
Remarks
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Aliphatic naphtha
Isopropyl alcohol
Clean cloth
C-305
C-385
C-516
AR
AR
AR
Remarks
Procedure
NOTE
The following overhaul instructions apply to 412-010-100-ALL except where noted in text.
NOTE
If the main rotor hub is being disassembled for replacement of parts instead of overhaul, disassemble
only to the extent necessary to replace the parts.
1.
Table 1. Hub Assembly 412-010-100
STEPS
HUB DASH NUMBERS
Step 1. to Step 5.
All hubs
Step 6. to Step 10.
-121
Step 11. to Step 19.
All hubs
Step 20. to Step 34.
-139 (Post BHT-412-SI-21), -145
Step 35. to Step 59.
-151, -159, -177, -181 (1) , -193 (1)
Step 58. and Step 59.
-139 (Post BHT-412-SI-21), -145, -151, -159, -171, -175,
-181 (1) , -193 (1) , -195, -209
NOTE
1
Helicopters S/N 36020 and subsequent, including S/N 46400 through 46499, and helicopters modified by
412-570-001-103.
Install the hub assembly on the buildup bench assembly (T101263-101) (Figure 1).
NOTE
Step 2. through Step 15. are for disassembly of one spindle and yoke end. Procedures are identical for
the remaining spindle and yoke ends.
2.
Remove the plug (85, Figure 2, Detail K), lock (84), nut (83), and washer (82).
3.
Remove the blade bolt (81).
EXPANDABLE BOLT HANDLE SHALL NOT BE CLOSED WHEN THE BOLT IS NOT INSTALLED.
FAILURE TO FOLLOW THIS CAUTION COULD RESULT IN DAMAGING THE BOLT RING
SEGMENTS.
4.
Remove the expandable blade bolt (86) (BHT-412-MM, Chapter 62).
Applicable to: ALL
412-A-62-20-00-00A-530A-B
ECCN EAR99
31 MAY 2023 Page 00050-1
BHT-412-CRO
PAY PARTICULAR ATTENTION NOT TO DISTURB THE RING SEGMENT ORDER AND
ORIENTATION DURING THE DISASSEMBLY AND ASSEMBLY OF THE EXPANDABLE BOLT.
5.
If necessary, disassemble the expandable blade bolt (1, Figure 3) as follows:
5.1.
Clean the expandable bolt with a cloth moistened with aliphatic naphtha (C-305) or isopropyl alcohol (C-385) and
wipe dry with a clean cloth (C-516).
5.2.
Make sure the bolt handle (2) is in the open position.
5.3.
Remove the nut (4) from the core pin (5).
5.4.
Attach the removal/installation workaid to the threaded end of the core pin (5) until firmly seated (hand tighten only).
5.5.
Slide the segments (3) from the core pin (5) onto the removal/installation workaid.
5.6.
Remove the spacer (Figure 3) and inspect its internal bore for a machining groove or offset in the center of the
spacer. Replace any spacers with a machining anomaly in the internal bore.
5.7.
Clean the segments (3) and the core pin (5) with aliphatic naphtha (C-305) or isopropyl alcohol (C-385) paying
particular attention not to disturb the orientation and order of the segments. Separate the segments to remove
all dirt and debris.
5.8.
Thoroughly dry the segments (3) and the core pin (5) with clean compressed air.
Applicable: Main rotor hub 412-010-100-121:
6.
Remove the nuts (40 and 41, Figure 2, Detail E), washers (39 and 42), and bolts (28 and 30) with washers (29 and 31).
7.
Remove the upper and lower damper bridges (27 and 38) with the damper set halves (25 and 37) and the shims (26).
8.
Remove the four bolts (36) and the steel washers (35).
9.
Separate the spindle assembly (18) from the yoke end.
10.
Remove the two bolts (34) and the steel washers (33). Separate the pivot bearing (32) from the spindle assembly (18).
Applicable: All hubs:
11.
Remove the nut (51, Section F-F), bolt (46), steel washers (47 and 50), and remove the balance weights (48)
from the upper yoke assembly (1).
12.
Remove the two cotter pins (24, Detail D), nuts (23), steel washers (22), and bolts (20) and remove the fitting
(19) from the yoke. Discard the cotter pins.
13.
For helicopters Post TB 412-03-190 or S/N 36120 and subsequent, remove the cotter pins (118, Detail D), nuts (117),
washers (116 and 115), and bolts (114) and remove the fitting (19) from the yoke. Discard the cotter pins.
14.
Mount the spindle assembly (18, Detail C) in a suitable holding fixture.
15.
Cut and remove lockwire from bolt (13). Remove the bolt (13) and the washer (14). Separate the pitch horn (16) with
the pins (15) from the spindle assembly (18).
16.
Cut and remove lockwire from bolts (3, Detail A). Remove the eight bolts (3), nuts (7), washers (8), and drive
pins (2). Remove the upper cone seat (4).
17.
Lift the upper yoke assembly (1) from the splined plate (5).
18.
Remove the splined plate (5) and the eight drive pins (2) from the lower yoke assembly (6).
19.
Lift the lower yoke assembly (6) from the lower cone seat (9) and remove the lower cone seat from the buildup
bench assembly (T101263-101).
Applicable: Main rotor hubs 412-010-100-139 (Post BHT-412-SI-21) and 412-010-100-145:
20.
Remove the cotter pin (80, Detail J) nut (55), bolt (61), and washers (56 and 57), and remove the clevis assembly (62)
from the lug on the lower cone seat (12). Discard the cotter pin.
412-A-62-20-00-00A-530A-B
Applicable to: ALL
Page 00050-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
21.
Cut and remove lockwire from bolts (53 and 74). Remove the two bolts (53) and two bolts (74) and separate the cam
(76) and droop restraint system from the lower damper bridge (52). Proceed toStep 59. for the disassembly of the
droop restraint system.
22.
Remove the two bolts (28, Detail H) and two bolts (30).
MARK LOCATION OF DAMPERS TO ENSURE INSTALLATION IN SAME LOCATION.
23.
Remove the upper and lower damper bridges (27 and 52) with the damper set halves (25 and 37) and shims (26).
24.
Remove the two bolts (36) and steel washer (35). Separate the spindle assembly (18) from the yoke end.
25.
Remove the two bolts (34) and the steel washers (33).Separate the pivot bearing (32) from the spindle assembly (18).
26.
Remove the bolt and balance weights from the yoke (identical arrangement to bolt (46, Detail E) and balance
weights (48)).
27.
Remove the two bolts (20, Detail D) and remove the fitting (19) from the yoke.
28.
Mount the spindle assembly (18, Detail C) in a suitable holding fixture.
29.
Cut and remove lockwire from bolt (13). Remove the bolt (13) and washer (14). Separate the pitch horn (16) with the
pins (15) from the spindle assembly (18).
30.
Cut and remove lockwire from bolts (3, Detail B). Remove the eight bolts (3, Detail B) and remove the upper cone
seat (4).
31.
Lift the upper yoke assembly (10) from the splined plate (5).
32.
Remove the splined plate (5) and eight drive pins (2) from the lower yoke assembly (11).
33.
Lift the lower yoke assembly (11) from the lower cone seat (12) and remove the lower cone seat from the hub buildup
assembly adapter (3, Figure 1).
34.
Cut and remove lockwire from nuts (60, Figure 2, Detail J). Remove the bolts (59) and nuts (60) from the lug of
the lower cone seat (12).
Applicable: Main rotor hubs 412-010-100-151, -159, -171, -175, -181, -193, -195, and -209:
35.
Remove the arm and bearing assembly (112, Detail M) as follows:
35.1.
Remove the nuts (113), bolts (110), and washers (111).
35.2.
Mark the location of the arm and bearing assembly (112) to the yoke for assembly in the same location.
NOTE
Washer (109) NAS1149E0863P is optional and may or may not be installed between nut (105) and washer
(104).
36.
Remove the cotter pin (106, Detail L). Remove the nut (105) and washers (109, 104, and 102), and bolt (103) and
separate the assembled arm (100) from the bracket (107). Discard the cotter pin.
37.
Cut and remove lockwire from bolts (90). Remove the two nuts (87) and washers (88). Remove the two bolts
(90) with the four washers (89).
38.
Cut and remove lockwire from bolt (91). Remove the bolt (91) with the two washers (92). For helicopters S/N 33001
through 33136 only, separate the weight (93) and the shim (94) from the assembled arm (100).
NOTE
Retain and mark shims (96) to location removed from, to aid in reassembly.
Disassembly procedures are identical for either side of arm.
39.
Remove retaining ring (98), retainer (97), shim (96), washer (95), and bearing (99) from arm (100).
40.
Remove inner race (101) from arm (100).
Applicable to: ALL
412-A-62-20-00-00A-530A-B
ECCN EAR99
31 MAY 2023 Page 00050-3
BHT-412-CRO
41.
Remove plug (85, Detail K), lock (84), nut (83), and washer (82).
42.
Remove blade bolt (81).
43.
Unlock expandable blade bolt (86) and remove.
44.
Remove cotter pin (80, Detail J), nut (55), bolt (61), and washers (56 and 57) and remove clevis assembly (62)
from lug on lower cone seat (12). Discard cotter pin.
45.
Cut and remove lockwire from bolts (53 and 74). Remove two nuts (77), washers (54), two bolts (53), two bolts (74),
and washers (75). Separate cam (76) and droop restraint system from lower damper bridge (52). Proceed to
Step 59. for disassembly of droop restraint system.
46.
Mount spindle assembly (18, Detail C) in a suitable holding fixture.
47.
Cut and remove lockwire from bolt (13). Remove bolt (13) and washer (14). Separate pitch horn (16) with pins
(15) from spindle assembly (18).
48.
Remove two bolts (28 and 30, Detail H) and two washers (29 and 31).
MARK LOCATION OF DAMPERS TO ENSURE INSTALLATION IN SAME LOCATION.
49.
Remove upper and lower damper bridges (27 and 52), with damper set halves (25 and 37) and shims (26).
50.
On damper sets 412-010-145-101 and -103, remove nuts (51C, Detail G), washers (51D), bushings (51E), and bolts
(51F), to separate damper halves (51A and 51G) from damper bearing (51H).
51.
Remove two bolts (36, Detail H) and steel washers (35). Separate spindle assembly (18) from yoke end.
VERIFY INSERT IS SEATED IN PIVOT BEARING (32) BEFORE BEARING REMOVAL. POSSIBLE
SCORING OF SPINDLE ASSEMBLY (18) COULD OCCUR.
52.
Remove two bolts (34) and steel washers (33). Separate pivot bearing (32) from spindle assembly (18).
53.
Remove two cotter pins (24, Detail D), nuts (23), steel washers (22), and bolts (20). Remove fitting (19) from
yoke. Discard cotter pins.
NOTE
On main rotor hubs 412-010-100-181, -193, -195, and -209, if upper and lower cone seats and splined
plate assembly are too tight for removal by hand, parts may be heated (not to exceed 180°F (82°C)) with
heat lamps, for ease of disassembly.
54.
Cut and remove lockwire from bolts (3). Remove eight nuts (7, Detail B), washers (8), and bolts (3). Remove
upper cone seat (4).
55.
Lift upper yoke assembly (10) from splined plate (5).
56.
Remove splined plate (5) and eight drive pins (2) from lower yoke assembly (11).
57.
Lift lower yoke assembly (11) from lower cone seat (12) and remove lower cone seat from hub buildup assembly
adapter (3, Figure 1).
Applicable: Main rotor hubs 412-010-100-139 (Post BHT-412-SI-21), -145, -151, -159, -171, -175, -181, -193, -195, and -209:
58.
Cut and remove lockwire from nuts (60,Figure 2, Detail J).Remove bolts (59) and nuts (60) from lug of lower cone
seat (12).
59.
Disassemble droop restraint system as follows:
59.1.
Remove nut (73), washers (70), and bolt (71) and remove weight (72) from between arms (65).
59.2.
Cut and remove lockwire from bolts (69). Remove bolts (69) and washers (68) securing arms (65) to both sides of
clevis (64).
412-A-62-20-00-00A-530A-B
Applicable to: ALL
Page 00050-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
59.3.
Remove cotter pin (80), nut (78), washers (66), and bolt (67) and remove arms (65). Discard cotter pin. Separate
cam (76) from clevis (64) and remove bushing (79) from cam.
59.4.
Cut and remove lockwire from nut (63). Loosen nut (63) and remove clevis (64) from clevis assembly (62). Remove
nut from clevis.
59.5.
Remove races (58) from clevis assembly (62).
Applicable to: ALL
412-A-62-20-00-00A-530A-B
ECCN EAR99
31 MAY 2023 Page 00050-5
BHT-412-CRO
ICN-412-A-622000-B-97499-00001-A-001-01
Figure 1. Main Rotor Hub Buildup Assembly - Tool Application (T101263-101) (Sheet 1 of 1)
412-A-62-20-00-00A-530A-B
Applicable to: ALL
Page 00050-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00002-A-001-01
Figure 2. Main Rotor Hub Assembly (Sheet 1 of 9)
Applicable to: ALL
412-A-62-20-00-00A-530A-B
ECCN EAR99
31 MAY 2023 Page 00050-7
BHT-412-CRO
ICN-412-A-622000-B-97499-00003-A-001-01
Figure 2. Main Rotor Hub Assembly (Sheet 2 of 9)
412-A-62-20-00-00A-530A-B
Applicable to: ALL
Page 00050-8 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00004-A-001-01
Figure 2. Main Rotor Hub Assembly (Sheet 3 of 9)
Applicable to: ALL
412-A-62-20-00-00A-530A-B
ECCN EAR99
31 MAY 2023 Page 00050-9
BHT-412-CRO
ICN-412-A-622000-B-97499-00005-A-001-01
Figure 2. Main Rotor Hub Assembly (Sheet 4 of 9)
412-A-62-20-00-00A-530A-B
Applicable to: ALL
Page 00050-10 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00006-A-001-01
Figure 2. Main Rotor Hub Assembly (Sheet 5 of 9)
Applicable to: ALL
412-A-62-20-00-00A-530A-B
ECCN EAR99
31 MAY 2023 Page 00050-11
BHT-412-CRO
ICN-412-A-622000-B-97499-00007-A-001-01
Figure 2. Main Rotor Hub Assembly (Sheet 6 of 9)
412-A-62-20-00-00A-530A-B
Applicable to: ALL
Page 00050-12 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00008-A-001-01
Figure 2. Main Rotor Hub Assembly (Sheet 7 of 9)
Applicable to: ALL
412-A-62-20-00-00A-530A-B
ECCN EAR99
31 MAY 2023 Page 00050-13
BHT-412-CRO
ICN-412-A-622000-B-97499-00009-A-001-01
Figure 2. Main Rotor Hub Assembly (Sheet 8 of 9)
412-A-62-20-00-00A-530A-B
Applicable to: ALL
Page 00050-14 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00010-A-001-01
Figure 2. Main Rotor Hub Assembly (Sheet 9 of 9)
Applicable to: ALL
412-A-62-20-00-00A-530A-B
ECCN EAR99
31 MAY 2023 Page 00050-15
BHT-412-CRO
ICN-412-A-622000-B-97499-00011-A-001-01
Figure 3. Expandable Blade Bolt - Disassembly (Sheet 1 of 2)
412-A-62-20-00-00A-530A-B
Applicable to: ALL
Page 00050-16 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00012-A-001-01
Figure 3. Expandable Blade Bolt - Disassembly (Sheet 2 of 2)
Applicable to: ALL
412-A-62-20-00-00A-530A-B
ECCN EAR99
31 MAY 2023 Page 00050-17
BHT-412-CRO
Intentionally blank page
412-A-62-20-00-00A-530A-B
Applicable to: ALL
Page 00050-18 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Hub - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Corrosion preventive oil
Polyurethane thinner
Drycleaning solvent
MEK
Cleaning compound
Abrasive cloth or paper
Barrier material
Barrier tape
Paint remover
Paint remover
C-126
C-235
C-304
C-309
C-318
C-423
C-427
C-456
C-435
C-436
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
Remarks
Procedure
DO NOT CLEAN ELASTOMERIC BEARINGS WITH drycleaning solvent (C-304).
1.
Clean pivot bearing (32, Figure 1), damper bearing (17), and damper set half (25 and 37) with a mixture of cleaning
compound (C-318) and distilled or deionized water. Use 10 to 15% by volume of cleaning compound in mixture.
2.
Clean all other main rotor hub parts with drycleaning solvent (C-304).
3.
Allow parts to drip dry or use low pressure filtered air.
4.
Remove buffers (21, 43, 44, and 45) from yoke by scraping with a sharp piece of plastic.
5.
Remove aged sealant, color code markings, and adhesive by scraping with a sharp piece of plastic. Finish by
lightly sanding with abrasive cloth or paper (C-423).
DO NOT ALLOW PAINT REMOVER TO CONTACT ELASTOMER ELEMENT OF DAMPER BEARINGS,
PIVOT BEARINGS, DAMPER SETS OR ANY EPOXY RESIN COATED AREAS OF COMPONENTS.
DO NOT USE CHLORINATED HYDROCARBON paint remover (C-435) ON TITANIUM YOKE.
6.
Strip acrylic lacquer using chlorinated hydrocarbon paint remover (C-435) from parts that require magnetic particle
inspection, with the exception of titanium yokes (10 and 11). Strip all organic finish from parts that require fluorescent
penetrant inspection. Refer to Step 7. for procedures to strip titanium yoke. Refer to BHT-ALL-SPM, Standard
Practices Manual for procedure to strip paint.
7.
Paint may be removed from the titanium yoke as follows:
7.1.
Plastic media blasting is the preferred method and is to be accomplished in accordance with the
BHT-ALL-SPM, Standard Practices Manual. To ensure all plastic media residue is removed, clean the yoke with a
clean rag soaked with MEK (C-309) or polyurethane thinner (C-235).
7.2.
If solvent stripping is used, paint remover (C-436) is to be utilized. Immediately following the stripping procedure,
clean the yoke with cleaning compound (C-318). Refer to the BHT-ALL-SPM, Standard Practices Manual for stripping
procedures.
8.
Remove solid film lubricant where required to facilitate inspection and repair. Refer to the BHT-ALL-SPM, Standard
Practices Manual for application of solid film lubricant.
9.
When parts are not to be processed immediately after cleaning, apply corrosion preventive oil (C-126) to all parts to
protect against corrosion. Wrap parts in barrier material (C-427) and secure with barrier tape (C-456).
Applicable to: ALL
412-A-62-20-00-00A-258A-B
ECCN EAR99
31 MAY 2023 Page 00051-1
BHT-412-CRO
ICN-412-A-622000-B-97499-00002-A-001-01
Figure 1. Main Rotor Hub Assembly (Sheet 1 of 9)
412-A-62-20-00-00A-258A-B
Applicable to: ALL
Page 00051-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00003-A-001-01
Figure 1. Main Rotor Hub Assembly (Sheet 2 of 9)
Applicable to: ALL
412-A-62-20-00-00A-258A-B
ECCN EAR99
31 MAY 2023 Page 00051-3
BHT-412-CRO
ICN-412-A-622000-B-97499-00004-A-001-01
Figure 1. Main Rotor Hub Assembly (Sheet 3 of 9)
412-A-62-20-00-00A-258A-B
Applicable to: ALL
Page 00051-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00005-A-001-01
Figure 1. Main Rotor Hub Assembly (Sheet 4 of 9)
Applicable to: ALL
412-A-62-20-00-00A-258A-B
ECCN EAR99
31 MAY 2023 Page 00051-5
BHT-412-CRO
ICN-412-A-622000-B-97499-00006-A-001-01
Figure 1. Main Rotor Hub Assembly (Sheet 5 of 9)
412-A-62-20-00-00A-258A-B
Applicable to: ALL
Page 00051-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00007-A-001-01
Figure 1. Main Rotor Hub Assembly (Sheet 6 of 9)
Applicable to: ALL
412-A-62-20-00-00A-258A-B
ECCN EAR99
31 MAY 2023 Page 00051-7
BHT-412-CRO
ICN-412-A-622000-B-97499-00008-A-001-01
Figure 1. Main Rotor Hub Assembly (Sheet 7 of 9)
412-A-62-20-00-00A-258A-B
Applicable to: ALL
Page 00051-8 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00009-A-001-01
Figure 1. Main Rotor Hub Assembly (Sheet 8 of 9)
Applicable to: ALL
412-A-62-20-00-00A-258A-B
ECCN EAR99
31 MAY 2023 Page 00051-9
BHT-412-CRO
ICN-412-A-622000-B-97499-00010-A-001-01
Figure 1. Main Rotor Hub Assembly (Sheet 9 of 9)
412-A-62-20-00-00A-258A-B
Applicable to: ALL
Page 00051-10 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Hub - Inspection
Procedure
1.
NOTE
If records and/or physical appearance of the main rotor hub indicate that the hub has been subjected
to an accident or incident outside the realm of normal usage, perform the conditional inspection
412-A-62-20-00-00A-284A-B / 00053. Refer to the BHT-412-MM, Chapter 5 for the definition of accidents
or incidents that require a conditional inspection be conducted. If the main rotor hub does not require a
conditional inspection, proceed with the normal inspection 412-A-62-20-00-00A-280B-B / 00054.
Applicable to: ALL
412-A-62-20-00-00A-280A-B
ECCN EAR99
31 MAY 2023 Page 00052-1
BHT-412-CRO
Intentionally blank page
412-A-62-20-00-00A-280A-B
Applicable to: ALL
Page 00052-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Hub - Conditional Inspection
Procedure
1.
Inspect the hub assembly visually for obvious damage. If any of the following discrepancies are present, the hub is
non-airworthy and nonrepairable:
1.1.
Any part of mast remaining in the hub.
1.2.
Pitch horn pulled from spindle.
1.3.
Yoke flexure bent beyond limits Figure 1.
1.4.
Spindle grips bent or bolt holes out of round. Refer to Figure 2 for procedure to perform inspection.
2.
Perform the normal inspection 412-A-62-20-00-00A-280B-B / 00054.
Applicable to: ALL
412-A-62-20-00-00A-284A-B
ECCN EAR99
31 MAY 2023 Page 00053-1
BHT-412-CRO
ICN-412-A-622000-B-97499-00013-A-001-01
Figure 1. Main Rotor Yoke Assembly - Damage Repair Limits (Sheet 1 of 2)
412-A-62-20-00-00A-284A-B
Applicable to: ALL
Page 00053-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00014-A-001-01
Figure 1. Main Rotor Yoke Assembly - Damage Repair Limits (Sheet 2 of 2)
Applicable to: ALL
412-A-62-20-00-00A-284A-B
ECCN EAR99
31 MAY 2023 Page 00053-3
BHT-412-CRO
ICN-412-A-622000-B-97499-00015-A-001-01
Figure 2. Main Rotor Hub Spindle Assembly - Damage Repair Limits (Sheet 1 of 2)
412-A-62-20-00-00A-284A-B
Applicable to: ALL
Page 00053-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00016-A-001-01
Figure 2. Main Rotor Hub Spindle Assembly - Damage Repair Limits (Sheet 2 of 2)
Applicable to: ALL
412-A-62-20-00-00A-284A-B
ECCN EAR99
31 MAY 2023 Page 00053-5
BHT-412-CRO
Intentionally blank page
412-A-62-20-00-00A-284A-B
Applicable to: ALL
Page 00053-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Hub - Normal Inspection
Procedure
1.
Examine the upper cone seat (4, Figure 1) per Figure 2 and 412-A-62-20-00-00A-353A-B / 00055.
2.
Examine the upper and lower cones per Figure 3.
3.
Examine the splined plate (5, Figure 1) per Figure 4 and 412-A-62-20-00-00A-353A-B / 00055.
4.
Examine the dowel pins (9A, Figure 1) per Figure 4.
5.
Examine the lower cone seat (9, Figure 1) per Figure 5 and 412-A-62-20-00-00A-353A-B / 00055.
6.
Examine the expandable blade bolt (1, Figure 6) per Figure 7.
7.
Examine the blade bolt (81, Figure 1) per Figure 8 and 412-A-62-20-00-00A-353A-B / 00055.
8.
Examine the pitch horn (16, Figure 1) per Figure 9 and 412-A-62-20-00-00A-353A-B / 00055. Repair the small
scratches on the external surfaces of the pitch horn lugs that attach to the pitch link per 412-A-62-20-00-00A-685A-B /
00056.
9.
Examine the spindle assembly (18, Figure 1) per Figure 10 and 412-A-62-20-00-00A-353A-B / 00055.
10.
Examine the upper and lower yoke assemblies (1 and 6, Figure 1) per Figure 11 and 412-A-62-20-00-00A-353A-B /
00055.
11.
Examine the drive pin (2, Figure 1) per Figure 12 and 412-A-62-20-00-00A-353A-B / 00055.
12.
Examine the fitting (19, Figure 1) per Figure 13 and 412-A-62-20-00-00A-353A-B / 00055.
13.
Examine the upper and lower damper bridges (27 and 38, Figure 1) per Figure 14 and 412-A-62-20-00-00A-353A-B /
00055.
NOTE
When you examine the main rotor hub elastomeric components, use the glossary of inspection
terminology as follows:
Sheeting: A layer of the elastomer that protrudes from the component.
Crumbling: Small particles of the elastomer that isolates from the component.
Extruding: The string-like elastomer that is produced by the component.
Delamination: Use a strong light to examine the bond line failure.
14.
Examine the pivot bearing (32) per Figure 15.
IT IS NOT POSSIBLE TO REBOND OR REPLACE THE DAMPER BEARING ON THE SPINDLE
ASSEMBLY. IF DAMPER BEARING FAILS INSPECTION, SEND THE SPINDLE ASSEMBLY AND
DAMPER BEARING TO BELL HELICOPTER, TEXTRON, ATTENTION: CPR, FOR EVALUATION
AND REPAIR.
15.
Examine the damper bearing (17) per Figure 16.
NOTE
Damper sets are aligned by the serial number. Keep integrity during the inspection, overhaul, and
replacement process.
16.
Examine the damper set halves (25 and 37) per Figure 17.
NOTE
Shimming controls the tolerances in the stack-up and adds a preload to the damper set.
17.
Examine the shim (26, Figure 1) as follows:
17.1.
Examine the shim (26) for the nicks, scoring, or delamination. If a defect is found, the shim (26) can be bonded to
keep correct shim (26) thickness.
Applicable to: ALL
412-A-62-20-00-00A-280B-B
ECCN EAR99
14 NOV 2023 Page 00054-1
BHT-412-CRO
17.2.
Examine the shim (26) thickness as follows:
17.2.1.
Assemble the damper bridges (27 and 38, Detail E) or (27 and 52, Detail G), without the damper set and spindles,
to the yokes with the two inboard bolts (30), washers (31 and 39), and nuts (40). Torque the nuts (40) to 70
foot-pounds (94.9 Nm).
17.2.2.
Measure the distance between the internal surfaces of the bridges at two locations. Average the sum of the
measurements and record the number as dimension A (Figure 18). Find dimension A for the remaining bridge sets.
17.2.3.
Put the spindle assembly (18, Figure 1, Detail C) on the work bench and install the damper sets (25 and 37) on the
spindle bearing boss (Figure 19). For non bolt on dampers, use a 6.0 inches (152.4 mm) C-clamp to hold the
dampers to the bearings. Tighten the C-clamp to prevent movement. Do not compress the dampers. Measure the
width of two dampers in two locations. Average the sum of the measurements and record as dimension B. Find
dimension B for the remaining damper sets.
17.2.4.
Add dimension A to the damper preload. Subtract dimension B from the sum. Divide the difference by two to get the
correct shim thickness for each shim on the damper set.
EXAMPLE: (DIM. A + 0.085 - DIM. B)/2 = Shim Thickness
Dimension A - 4.715 inches (119.8 mm)
Dimension B - 4.768 inches (121.1 mm)
Damper preload 0.085 inches (2.2 mm)
Given
Shim Thickness 0.016 inches (.4 mm)
NOTE
For very low shim values (0.003 inches (.1 mm)), it is permitted to double the value and shim only one
damper half. For values less than or equal to zero, no more shimming is required. Shim tolerance is plus
or minus 0.002 inches (.1 mm) for each bridge/damper half.
NOTE
There is a possibility that the 0.085 inches (2.2 mm) preIoad value may not be obtainable with dampers
that have been in service for extended periods of time. In this case, installation of one full (one only)
shim per side will provide satisfactory results. Although shim thickness required per side (to obtain 0.085
inches (2.2 mm) preload), exceeds the maximum thickness allowable. The resulting preload obtained will
prove satisfactory.
18.
Examine the pitch horn retaining pins (15, Figure 1) for mechanical or corrosion damage. If you visually find a defect,
replace the pitch horn retaining pins (15).
19.
Examine the feathering stop (49) for mechanical or corrosion damage. If you visually find a defect, replace the
feathering stop (49).
20.
Examine all bolts and assembly hardware for mechanical or corrosion damage. If you visually find a defect, replace
the defective bolts or assembly hardware.
Applicable: Main rotor hubs 412-010-100-139 (Post BHT-412-SI-21), -145, -151, -159, -171, -175, -181, -193, -195, and -209:
21.
Do the steps that follow:
21.1.
Examine the lower cone seat (12) per Figure 5 and 412-A-62-20-00-00A-353A-B / 00055.
21.2.
Examine the upper and lower yoke assembly (10 and 11) per Figure 20 and 412-A-62-20-00-00A-353A-B / 00055.
21.3.
Examine the upper and lower damper bridge (27 and 38) per Figure 14 and 412-A-62-20-00-00A-353A-B / 00055.
21.4.
Examine the droop restraint system components (53 through 80) per Figure 21.
22.
Examine the detail parts of the arm and bearing assembly for damage per Figure 22 and 412-A-62-20-00-00A-353A-B
/ 00055.
23.
Examine the bearings for wear and roughness of rotation.
412-A-62-20-00-00A-280B-B
Applicable to: ALL
Page 00054-2 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00002-A-001-01
Figure 1. Main Rotor Hub Assembly (Sheet 1 of 9)
Applicable to: ALL
412-A-62-20-00-00A-280B-B
ECCN EAR99
14 NOV 2023 Page 00054-3
BHT-412-CRO
ICN-412-A-622000-B-97499-00003-A-001-01
Figure 1. Main Rotor Hub Assembly (Sheet 2 of 9)
412-A-62-20-00-00A-280B-B
Applicable to: ALL
Page 00054-4 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00004-A-001-01
Figure 1. Main Rotor Hub Assembly (Sheet 3 of 9)
Applicable to: ALL
412-A-62-20-00-00A-280B-B
ECCN EAR99
14 NOV 2023 Page 00054-5
BHT-412-CRO
ICN-412-A-622000-B-97499-00005-A-001-01
Figure 1. Main Rotor Hub Assembly (Sheet 4 of 9)
412-A-62-20-00-00A-280B-B
Applicable to: ALL
Page 00054-6 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00006-A-001-01
Figure 1. Main Rotor Hub Assembly (Sheet 5 of 9)
Applicable to: ALL
412-A-62-20-00-00A-280B-B
ECCN EAR99
14 NOV 2023 Page 00054-7
BHT-412-CRO
ICN-412-A-622000-B-97499-00007-A-001-01
Figure 1. Main Rotor Hub Assembly (Sheet 6 of 9)
412-A-62-20-00-00A-280B-B
Applicable to: ALL
Page 00054-8 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00008-A-001-01
Figure 1. Main Rotor Hub Assembly (Sheet 7 of 9)
Applicable to: ALL
412-A-62-20-00-00A-280B-B
ECCN EAR99
14 NOV 2023 Page 00054-9
BHT-412-CRO
ICN-412-A-622000-B-97499-00009-A-001-01
Figure 1. Main Rotor Hub Assembly (Sheet 8 of 9)
412-A-62-20-00-00A-280B-B
Applicable to: ALL
Page 00054-10 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00010-A-001-01
Figure 1. Main Rotor Hub Assembly (Sheet 9 of 9)
Applicable to: ALL
412-A-62-20-00-00A-280B-B
ECCN EAR99
14 NOV 2023 Page 00054-11
BHT-412-CRO
ICN-412-A-622000-B-97499-00017-A-001-01
Figure 2. Main Rotor Hub Upper Cone Seat - Damage Repair Limits (Sheet 1 of 1)
412-A-62-20-00-00A-280B-B
Applicable to: ALL
Page 00054-12 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00018-A-001-01
Figure 3. Main Rotor Hub Upper and Lower Cones - Damage Repair Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-62-20-00-00A-280B-B
ECCN EAR99
14 NOV 2023 Page 00054-13
BHT-412-CRO
ICN-412-A-622000-B-97499-00019-A-001-01
Figure 4. Main Rotor Hub Splined Plate Assembly - Damage Repair Limits (Sheet 1 of 2)
412-A-62-20-00-00A-280B-B
Applicable to: ALL
Page 00054-14 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00020-A-001-01
Figure 4. Main Rotor Hub Splined Plate Assembly - Damage Repair Limits (Sheet 2 of 2)
Applicable to: ALL
412-A-62-20-00-00A-280B-B
ECCN EAR99
14 NOV 2023 Page 00054-15
BHT-412-CRO
ICN-412-A-622000-B-97499-00021-A-001-01
Figure 5. Main Rotor Hub Lower Cone Seat (Pre/Post 412-SI-21) - Damage Repair Limits (Sheet 1 of 2)
412-A-62-20-00-00A-280B-B
Applicable to: ALL
Page 00054-16 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00022-A-001-01
Figure 5. Main Rotor Hub Lower Cone Seat (Pre/Post 412-SI-21) - Damage Repair Limits (Sheet 2 of 2)
Applicable to: ALL
412-A-62-20-00-00A-280B-B
ECCN EAR99
14 NOV 2023 Page 00054-17
BHT-412-CRO
ICN-412-A-622000-B-97499-00011-A-001-01
Figure 6. Expandable Blade Bolt - Disassembly (Sheet 1 of 2)
412-A-62-20-00-00A-280B-B
Applicable to: ALL
Page 00054-18 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00012-A-001-01
Figure 6. Expandable Blade Bolt - Disassembly (Sheet 2 of 2)
Applicable to: ALL
412-A-62-20-00-00A-280B-B
ECCN EAR99
14 NOV 2023 Page 00054-19
BHT-412-CRO
ICN-412-A-622000-B-97499-00024-A-001-01
Figure 7. Expandable Blade Bolt - Damage Repair Limits (Sheet 1 of 1)
412-A-62-20-00-00A-280B-B
Applicable to: ALL
Page 00054-20 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00023-A-001-01
Figure 8. Main Rotor Blade Bolt Assembly - Damage Repair Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-62-20-00-00A-280B-B
ECCN EAR99
14 NOV 2023 Page 00054-21
BHT-412-CRO
ICN-412-A-622000-B-97499-00025-A-001-01
Figure 9. Main Rotor Hub Pitch Horn Assembly - Damage Repair Limits (Sheet 1 of 1)
412-A-62-20-00-00A-280B-B
Applicable to: ALL
Page 00054-22 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00015-A-001-01
Figure 10. Main Rotor Hub Spindle Assembly - Damage Repair Limits (Sheet 1 of 2)
Applicable to: ALL
412-A-62-20-00-00A-280B-B
ECCN EAR99
14 NOV 2023 Page 00054-23
BHT-412-CRO
ICN-412-A-622000-B-97499-00016-A-001-01
Figure 10. Main Rotor Hub Spindle Assembly - Damage Repair Limits (Sheet 2 of 2)
412-A-62-20-00-00A-280B-B
Applicable to: ALL
Page 00054-24 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00013-A-001-01
Figure 11. Main Rotor Yoke Assembly - Damage Repair Limits (Sheet 1 of 2)
Applicable to: ALL
412-A-62-20-00-00A-280B-B
ECCN EAR99
14 NOV 2023 Page 00054-25
BHT-412-CRO
ICN-412-A-622000-B-97499-00014-A-001-01
Figure 11. Main Rotor Yoke Assembly - Damage Repair Limits (Sheet 2 of 2)
412-A-62-20-00-00A-280B-B
Applicable to: ALL
Page 00054-26 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00026-A-001-01
Figure 12. Main Rotor Hub Drive Pin - Damage Repair Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-62-20-00-00A-280B-B
ECCN EAR99
14 NOV 2023 Page 00054-27
BHT-412-CRO
ICN-412-A-622000-B-97499-00027-A-001-01
Figure 13. Main Rotor Hub Fitting - Damage Repair Limits (Sheet 1 of 1)
412-A-62-20-00-00A-280B-B
Applicable to: ALL
Page 00054-28 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00028-A-001-01
Figure 14. Main Rotor Hub Damper Bridge - Damage Repair Limits (Sheet 1 of 2)
Applicable to: ALL
412-A-62-20-00-00A-280B-B
ECCN EAR99
14 NOV 2023 Page 00054-29
BHT-412-CRO
ICN-412-A-622000-B-97499-00029-A-001-01
Figure 14. Main Rotor Hub Damper Bridge - Damage Repair Limits (Sheet 2 of 2)
412-A-62-20-00-00A-280B-B
Applicable to: ALL
Page 00054-30 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00030-A-001-01
Figure 15. Main Rotor Hub Pivot Bearing - Damage Repair Limits (Sheet 1 of 2)
Applicable to: ALL
412-A-62-20-00-00A-280B-B
ECCN EAR99
14 NOV 2023 Page 00054-31
BHT-412-CRO
ICN-412-A-622000-B-97499-00031-A-001-01
Figure 15. Main Rotor Hub Pivot Bearing - Damage Repair Limits (Sheet 2 of 2)
412-A-62-20-00-00A-280B-B
Applicable to: ALL
Page 00054-32 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00032-A-001-01
Figure 16. Main Rotor Hub Damper Bearing - Damage Repair Limits (Sheet 1 of 2)
Applicable to: ALL
412-A-62-20-00-00A-280B-B
ECCN EAR99
14 NOV 2023 Page 00054-33
BHT-412-CRO
ICN-412-A-622000-B-97499-02878-A-001-01
Figure 16. Main Rotor Hub Damper Bearing - Damage Repair Limits (Sheet 2 of 2)
412-A-62-20-00-00A-280B-B
Applicable to: ALL
Page 00054-34 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00034-A-001-01
Figure 17. Main Rotor Hub Damper Set - Damage Repair Limits (Sheet 1 of 2)
Applicable to: ALL
412-A-62-20-00-00A-280B-B
ECCN EAR99
14 NOV 2023 Page 00054-35
BHT-412-CRO
ICN-412-A-622000-B-97499-00035-A-001-01
Figure 17. Main Rotor Hub Damper Set - Damage Repair Limits (Sheet 2 of 2)
412-A-62-20-00-00A-280B-B
Applicable to: ALL
Page 00054-36 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00036-A-001-01
Figure 18. Yoke and Bridge Assembly (Sheet 1 of 1)
Applicable to: ALL
412-A-62-20-00-00A-280B-B
ECCN EAR99
14 NOV 2023 Page 00054-37
BHT-412-CRO
ICN-412-A-622000-B-97499-00037-A-001-01
Figure 19. Yoke and Splined Assembly With Dampers (Sheet 1 of 1)
412-A-62-20-00-00A-280B-B
Applicable to: ALL
Page 00054-38 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00038-A-001-01
Figure 20. Main Rotor Yoke Assembly (Post BHT-412-SI-21) - Damage Repair Limits (Sheet 1 of 2)
Applicable to: ALL
412-A-62-20-00-00A-280B-B
ECCN EAR99
14 NOV 2023 Page 00054-39
BHT-412-CRO
ICN-412-A-622000-B-97499-00039-A-001-01
Figure 20. Main Rotor Yoke Assembly (Post BHT-412-SI-21) - Damage Repair Limits (Sheet 2 of 2)
412-A-62-20-00-00A-280B-B
Applicable to: ALL
Page 00054-40 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00040-A-001-01
Figure 21. Main Rotor Hub Droop Restraint Components - Damage Repair Limits (Sheet 1 of 5)
Applicable to: ALL
412-A-62-20-00-00A-280B-B
ECCN EAR99
14 NOV 2023 Page 00054-41
BHT-412-CRO
ICN-412-A-622000-B-97499-00041-A-001-01
Figure 21. Main Rotor Hub Droop Restraint Components - Damage Repair Limits (Sheet 2 of 5)
412-A-62-20-00-00A-280B-B
Applicable to: ALL
Page 00054-42 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00042-A-001-01
Figure 21. Main Rotor Hub Droop Restraint Components - Damage Repair Limits (Sheet 3 of 5)
Applicable to: ALL
412-A-62-20-00-00A-280B-B
ECCN EAR99
14 NOV 2023 Page 00054-43
BHT-412-CRO
ICN-412-A-622000-B-97499-00043-A-001-01
Figure 21. Main Rotor Hub Droop Restraint Components - Damage Repair Limits (Sheet 4 of 5)
412-A-62-20-00-00A-280B-B
Applicable to: ALL
Page 00054-44 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00044-A-001-01
Figure 21. Main Rotor Hub Droop Restraint Components - Damage Repair Limits (Sheet 5 of 5)
Applicable to: ALL
412-A-62-20-00-00A-280B-B
ECCN EAR99
14 NOV 2023 Page 00054-45
BHT-412-CRO
ICN-412-A-622000-B-97499-00045-A-001-01
Figure 22. Arm and Bearing Assembly - Damage Repair Limits (Sheet 1 of 1)
412-A-62-20-00-00A-280B-B
Applicable to: ALL
Page 00054-46 14 NOV 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Hub - Non-destructive Inspection
Procedure
1.
Do a Magnetic Particle Inspection (MPI) for the applicable parts shown in Table 1 in accordance with the instructions
provided in the BHT-ALL-SPM, Chapter 6, Standard Practices Manual.
2.
Do a Fluorescent Penetrant Inspection (FPI) for the applicable parts shown in Table 1 in accordance with the
instructions provided in the BHT-ALL-SPM, Chapter 6, Standard Practices Manual.
3.
Discard all the parts that fail the Non-Destructive Inspection (NDI) criteria.
4.
Use a gauss meter to make sure magnetization of the parts is less than 3 gauss anywhere on the part. Otherwise,
demagnetize the part per the instructions contained in the BHT-ALL-SPM, Chapter 6, Standard Practices Manual.
Table 1. Main Rotor Hub - Non-destructive Inspection
PART NUMBER
MAGNETIC
PARTICLE
INSPECTION
FLUORESCENT
PENETRANT
INSPECTION
FIGURE NUMBER
NOMENCLATURE
Figure 1 and Figure 2
Yoke
412-010-101
Figure 3
Fitting
412-010-111
X
Figure 4
Blade Bolts
412-010-124
X
Figure 5
Pitch Horn
412-010-149-101
X
Figure 5
Pitch Horn
412-010-149-105
X
Figure 5
Pitch Horn
412-010-149-111
Figure 6
Spindle
412-010-156
X
Figure 7
Drive Pin
412-010-166
X
Figure 8
Splined Plate
412-010-167
X
Figure 9
Lower Cone Seat
412-010-168
X
Figure 10
Lower Damper Bridge
412-010-170
Figure 8
Splined Plate
412-010-177
X
Figure 9
Lower Cone Seat
412-010-178
X
Figure 10
Upper Damper Bridge
412-010-183
X
Figure 10
Upper Damper Bridge
412-010-185
X
Figure 11
Upper Cone Seat
412-010-186
Figure 12
Arm and Bearing
Assembly
412-010-216
Figure 9
Lower Cone Seat
412-018-056
Figure 10
Lower Damper Bridge
412-018-068
X
X
X
X
X
X
X
Applicable to: ALL
412-A-62-20-00-00A-353A-B
ECCN EAR99
31 MAY 2023 Page 00055-1
BHT-412-CRO
ICN-412-A-622000-B-97499-00013-A-001-01
Figure 1. Main Rotor Yoke Assembly - Damage Repair Limits (Sheet 1 of 2)
412-A-62-20-00-00A-353A-B
Applicable to: ALL
Page 00055-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00014-A-001-01
Figure 1. Main Rotor Yoke Assembly - Damage Repair Limits (Sheet 2 of 2)
Applicable to: ALL
412-A-62-20-00-00A-353A-B
ECCN EAR99
31 MAY 2023 Page 00055-3
BHT-412-CRO
ICN-412-A-622000-B-97499-00038-A-001-01
Figure 2. Main Rotor Yoke Assembly (Post BHT-412-SI-21) — Damage Repair Limits (Sheet 1 of 2)
412-A-62-20-00-00A-353A-B
Applicable to: ALL
Page 00055-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00039-A-001-01
Figure 2. Main Rotor Yoke Assembly (Post BHT-412-SI-21) — Damage Repair Limits (Sheet 2 of 2)
Applicable to: ALL
412-A-62-20-00-00A-353A-B
ECCN EAR99
31 MAY 2023 Page 00055-5
BHT-412-CRO
ICN-412-A-622000-B-97499-00027-A-001-01
Figure 3. Main Rotor Hub Fitting - Damage Repair Limits (Sheet 1 of 1)
412-A-62-20-00-00A-353A-B
Applicable to: ALL
Page 00055-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00023-A-001-01
Figure 4. Main Rotor Blade Bolt Assembly - Damage Repair Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-62-20-00-00A-353A-B
ECCN EAR99
31 MAY 2023 Page 00055-7
BHT-412-CRO
ICN-412-A-622000-B-97499-00025-A-001-01
Figure 5. Main Rotor Hub Pitch Horn Assembly - Damage Repair Limits (Sheet 1 of 1)
412-A-62-20-00-00A-353A-B
Applicable to: ALL
Page 00055-8 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00015-A-001-01
Figure 6. Main Rotor Hub Spindle Assembly - Damage Repair Limits (Sheet 1 of 2)
Applicable to: ALL
412-A-62-20-00-00A-353A-B
ECCN EAR99
31 MAY 2023 Page 00055-9
BHT-412-CRO
ICN-412-A-622000-B-97499-00016-A-001-01
Figure 6. Main Rotor Hub Spindle Assembly - Damage Repair Limits (Sheet 2 of 2)
412-A-62-20-00-00A-353A-B
Applicable to: ALL
Page 00055-10 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00026-A-001-01
Figure 7. Main Rotor Hub Drive Pin - Damage Repair Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-62-20-00-00A-353A-B
ECCN EAR99
31 MAY 2023 Page 00055-11
BHT-412-CRO
ICN-412-A-622000-B-97499-00019-A-001-01
Figure 8. Main Rotor Hub Splined Plate Assembly - Damage Repair Limits (Sheet 1 of 2)
412-A-62-20-00-00A-353A-B
Applicable to: ALL
Page 00055-12 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00020-A-001-01
Figure 8. Main Rotor Hub Splined Plate Assembly - Damage Repair Limits (Sheet 2 of 2)
Applicable to: ALL
412-A-62-20-00-00A-353A-B
ECCN EAR99
31 MAY 2023 Page 00055-13
BHT-412-CRO
ICN-412-A-622000-B-97499-00021-A-001-01
Figure 9. Main Rotor Hub Lower Cone Seat (Pre/Post 412-SI-21) - Damage Repair Limits (Sheet 1 of 2)
412-A-62-20-00-00A-353A-B
Applicable to: ALL
Page 00055-14 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00022-A-001-01
Figure 9. Main Rotor Hub Lower Cone Seat (Pre/Post 412-SI-21) - Damage Repair Limits (Sheet 2 of 2)
Applicable to: ALL
412-A-62-20-00-00A-353A-B
ECCN EAR99
31 MAY 2023 Page 00055-15
BHT-412-CRO
ICN-412-A-622000-B-97499-00028-A-001-01
Figure 10. Main Rotor Hub Damper Bridge - Damage Repair Limits (Sheet 1 of 2)
412-A-62-20-00-00A-353A-B
Applicable to: ALL
Page 00055-16 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00029-A-001-01
Figure 10. Main Rotor Hub Damper Bridge - Damage Repair Limits (Sheet 2 of 2)
Applicable to: ALL
412-A-62-20-00-00A-353A-B
ECCN EAR99
31 MAY 2023 Page 00055-17
BHT-412-CRO
ICN-412-A-622000-B-97499-00017-A-001-01
Figure 11. Main Rotor Hub Upper Cone Seat - Damage Repair Limits (Sheet 1 of 1)
412-A-62-20-00-00A-353A-B
Applicable to: ALL
Page 00055-18 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00045-A-001-01
Figure 12. Arm and Bearing Assembly - Damage Repair Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-62-20-00-00A-353A-B
ECCN EAR99
31 MAY 2023 Page 00055-19
BHT-412-CRO
Intentionally blank page
412-A-62-20-00-00A-353A-B
Applicable to: ALL
Page 00055-20 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Hub - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Solid film lubricant
Chemical film material
Cadmium plating solution
Epoxy polyamide primer
Drycleaning solvent
Adhesive
Adhesive
Cleaner
Abrasive cloth or paper
Clean cloth
C-021
C-100
C-108
C-204
C-304
C-317
C-363
C-395
C-423
C-516
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
Remarks
Procedure
1.
Replace any part that shows evidence of failure, exceeds repairable limitations, or has reached its scheduled
retirement life.
2.
Polish out corrosion and mechanical damage on the main rotor hub components that is within limits
(412-A-62-20-00-00A-280B-B / 00054) as follows:
2.1.
Use 400 grit abrasive cloth or paper (C-423). Final polish to a scratch-free surface with fine grade abrasive cloth or
paper (C-423). Make sure all corrosion is removed.
2.2.
Apply cadmium plating solution (C-108) to the repaired areas on the steel parts where plating was removed. Refer
to Figure 1 for processing requirements and the BHT-ALL-SPM, Standard Practices Manual for cadmium plating
solution (C-108) procedures.
2.3.
Apply chemical film material (C-100) to bare areas on the aluminum parts. Refer to Figure 1 for processing
requirements and the BHT-ALL-SPM, Standard Practices Manual for chemical film treatment.
3.
Replace the bushings (1, 2, and 3, Figure 3) on the upper and lower yoke (10 and 11, Figure 2, Detail B) as follows:
3.1.
Heat the yokes (10 and 11) (not to exceed 400°F (204°C)) by immersion in hot oil or by placing parts in an oven for
a maximum of 2 hours.
3.2.
Cool the bushings (1, 2, or 3, Figure 3) using liquid nitrogen, refrigerator, cold box, or a mixture of dry ice and
denatured ethyl alcohol.
3.3.
Assembly shall proceed immediately after parts have been removed from heating and cooling.
4.
Bond the fretting buffers (21, 43, 44, and 45, Figure 2) on the upper and lower yoke assemblies (10 and 11) as
follows: (The yokes can have exposed areas around damper bridges primed and painted.)
NOTE
Remove corrosion protective oil from the yoke if necessary, with drycleaning solvent (C-304). Dry with
filtered, compressed air.
4.1.
Lightly sand areas of the yoke and the side of the buffer to be bonded with 320 grit abrasive cloth or paper (C-423)
and wipe clean with a clean cloth (C-516) moistened with drycleaning solvent (C-304). Dry with a clean, dry cloth.
NOTE
Titanium cleaner (C-395) is specifically designed to provide a strong chemical bond of adhesive to
titanium.
4.2.
Apply a brushed layer of cleaner (C-395) to areas of the yoke to be bonded. Allow to remain on the surface for 15
minutes. Rinse off with water and wipe dry with a clean cloth.
Applicable to: ALL
412-A-62-20-00-00A-685A-B
ECCN EAR99
31 MAY 2023 Page 00056-1
BHT-412-CRO
4.3.
Apply adhesive (C-363) to the buffer pad and area of the yoke to be bonded. Position the buffer on the yoke and
clamp lightly using suitable plates and C-clamps. Waxing of plates will allow easy removal after adhesive cures.
4.4.
Allow adhesive to cure for 24 hours at room temperature or for 2 hours at 155 to 165°F (69 to 74°C). Heat cure
is recommended to provide maximum bond strength.
5.
Refinish the main rotor hub components as shown in Figure 1. Refer to the BHT-ALL-SPM, Standard Practices
Manual for painting procedures.
6.
Apply solid film lubricant (C-021)to the mating surface of expandable blade bolt (86, Figure 2, Detail K). Refer to the
BHT-ALL-SPM, Standard Practices Manual for solid film lubricant application.
NOTE
Repairable damage of the expandable blade bolt is limited to blending/polishing with abrasive cloth or
paper 240-grit followed by 320 and 400-grit abrasive cloth or abrasive cloth or paper (C-423). Apply solid
film lubricant (C-021) to repaired areas and areas of burnished or missing dry film lube.
7.
Repair the pitch horn lugs as follows:
7.1.
For pitch horn lugs with scratches less than a depth of 0.002 inch (0.05 mm), do as follows:
NOTE
Maximum depth of repair is 0.002 inch (0.05 mm) (depth applies after repair is accomplished). This repair
may only be accomplished one time per surface.
7.1.1.
Scratches of less than 0.002 inch (0.05 mm) on the external surfaces of the pitch horn lugs (Figure 4, Note 4) that
attach to pitch links may be repaired using crocus cloth and/or scotch brite.
7.1.2.
After repair, brush cadmium plate on the repaired surface, then prime and paint.
7.2.
Pitch horn lugs with scratches exceeding a depth of 0.002 inch (0.05 mm) shall be returned to Bell for possible repair.
8.
Replace a dowel pin (9A) in the spilned plate (5) as follows:
DO NOT EXCEED THE MAXIMUM ALLOWABLE TEMPERATURE WHEN YOU HEAT A PART OR
DAMAGE TO THE PART MAY OCCUR.
8.1.
Apply heat to a maximum of 265°F (129°C) to the splined plate (5) adjacent to the dowel pin (9A).
8.2.
Press the dowel pin (9A) out.
8.3.
Clean the pin bore.
8.4.
Inspect the bore for damage. maximum bore dimension is not to exceed 0.3125 inch (7.938 mm).
8.5.
Apply heat to a maximum of 265°F (129°C) to the splined plate (5).
8.6.
Apply unreduced epoxy polyamide primer (C-204) to the mating diameter of the dowel pin (9A) and the splined plate
(5). The dowel pin can be cooled in a freezer or dry with ice to facilitate the installation.
8.7.
Press the dowel pin (9A) in the spilned plate (5). The dowel pin should not protude more than 0.400 inch (10.16 mm).
9.
Replace the seals and bearings of the clevis assembly (62) as follows:
NOTE
Purge grease out of clevis to ease disassembly.
Do not remove the two grease fittings from clevis body.
9.1.
Use a suitable pressing plug and press the seal and bearing out of the clevis assembly (62). The procedure is
the same on both sides.
9.2.
Inspect the clevis body damage limits as per Figure 7.
9.3.
Repair the clevis body as per Figure 1
412-A-62-20-00-00A-685A-B
Applicable to: ALL
Page 00056-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
9.4.
Use a suitable pressing plug and press new bearing into clevis body from the outer surface (Figure 6). The bearing
should be flush to 0.020 inch (0.51 mm) below outer surface face. The procedure is the same for both sides.
NOTE
The seal lip should be oriented towards the bearing.
9.5.
Use a suitable pressing plug and press new seal into clevis body from the inside surface. The seal should be flush to
0.020 inch (0.51 mm) below inner surface face. The procedure is the same for both sides.
9.6.
Fill the area between seal and bearing with applicable grease (412-MM, Chapter 12) through the fittings on each
side of the clevis.
10.
Replace the cork wood stopper (120-179-11A) in the main rotor blade bolt assembly (412-010-124-109) Figure 5
as follows:
10.1.
Lightly abraid the epoxy/zinc coating on faying surface of the bolt inside diameter using a 400 grit abrasive cloth or
paper. Do not completely remove the epoxy/zinc coating from the faying surface.
NOTE
During sanding, exercise care to prevent removal of the cadmium plating from unpainted inside diameter
surfaces.
10.2.
Apply a light coat of adhesive (C-317) to all surfaces of cork wood stopper.
10.3.
Install the cork wood stopper 0.06 to 0.12 inch (1.5 to 3.0 mm) below the top surface of bolt head.
10.4.
Fill over the top of cork wood stopper with adhesive (C-317) flush within ± 0.020 inch (± 0.51 mm) of top surface
of bolt head.
10.5.
Allow adhesive (C-317) to cure for 24 hours at room temperature.
Applicable to: ALL
412-A-62-20-00-00A-685A-B
ECCN EAR99
31 MAY 2023 Page 00056-3
BHT-412-CRO
ICN-412-A-622000-B-97499-00046-A-001-01
Figure 1. Main Rotor Hub Process (Sheet 1 of 8)
412-A-62-20-00-00A-685A-B
Applicable to: ALL
Page 00056-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00047-A-001-01
Figure 1. Main Rotor Hub Process (Sheet 2 of 8)
Applicable to: ALL
412-A-62-20-00-00A-685A-B
ECCN EAR99
31 MAY 2023 Page 00056-5
BHT-412-CRO
ICN-412-A-622000-B-97499-00048-A-001-01
Figure 1. Main Rotor Hub Process (Sheet 3 of 8)
412-A-62-20-00-00A-685A-B
Applicable to: ALL
Page 00056-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00049-A-001-01
Figure 1. Main Rotor Hub Process (Sheet 4 of 8)
Applicable to: ALL
412-A-62-20-00-00A-685A-B
ECCN EAR99
31 MAY 2023 Page 00056-7
BHT-412-CRO
ICN-412-A-622000-B-97499-00050-A-001-01
Figure 1. Main Rotor Hub Process (Sheet 5 of 8)
412-A-62-20-00-00A-685A-B
Applicable to: ALL
Page 00056-8 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00051-A-001-01
Figure 1. Main Rotor Hub Process (Sheet 6 of 8)
Applicable to: ALL
412-A-62-20-00-00A-685A-B
ECCN EAR99
31 MAY 2023 Page 00056-9
BHT-412-CRO
ICN-412-A-622000-B-97499-00052-A-001-01
Figure 1. Main Rotor Hub Process (Sheet 7 of 8)
412-A-62-20-00-00A-685A-B
Applicable to: ALL
Page 00056-10 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00053-A-001-01
Figure 1. Main Rotor Hub Process (Sheet 8 of 8)
Applicable to: ALL
412-A-62-20-00-00A-685A-B
ECCN EAR99
31 MAY 2023 Page 00056-11
BHT-412-CRO
ICN-412-A-622000-B-97499-00002-A-001-01
Figure 2. Main Rotor Hub Assembly (Sheet 1 of 9)
412-A-62-20-00-00A-685A-B
Applicable to: ALL
Page 00056-12 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00003-A-001-01
Figure 2. Main Rotor Hub Assembly (Sheet 2 of 9)
Applicable to: ALL
412-A-62-20-00-00A-685A-B
ECCN EAR99
31 MAY 2023 Page 00056-13
BHT-412-CRO
ICN-412-A-622000-B-97499-00004-A-001-01
Figure 2. Main Rotor Hub Assembly (Sheet 3 of 9)
412-A-62-20-00-00A-685A-B
Applicable to: ALL
Page 00056-14 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00005-A-001-01
Figure 2. Main Rotor Hub Assembly (Sheet 4 of 9)
Applicable to: ALL
412-A-62-20-00-00A-685A-B
ECCN EAR99
31 MAY 2023 Page 00056-15
BHT-412-CRO
ICN-412-A-622000-B-97499-00006-A-001-01
Figure 2. Main Rotor Hub Assembly (Sheet 5 of 9)
412-A-62-20-00-00A-685A-B
Applicable to: ALL
Page 00056-16 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00007-A-001-01
Figure 2. Main Rotor Hub Assembly (Sheet 6 of 9)
Applicable to: ALL
412-A-62-20-00-00A-685A-B
ECCN EAR99
31 MAY 2023 Page 00056-17
BHT-412-CRO
ICN-412-A-622000-B-97499-00008-A-001-01
Figure 2. Main Rotor Hub Assembly (Sheet 7 of 9)
412-A-62-20-00-00A-685A-B
Applicable to: ALL
Page 00056-18 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00009-A-001-01
Figure 2. Main Rotor Hub Assembly (Sheet 8 of 9)
Applicable to: ALL
412-A-62-20-00-00A-685A-B
ECCN EAR99
31 MAY 2023 Page 00056-19
BHT-412-CRO
ICN-412-A-622000-B-97499-00010-A-001-01
Figure 2. Main Rotor Hub Assembly (Sheet 9 of 9)
412-A-62-20-00-00A-685A-B
Applicable to: ALL
Page 00056-20 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00054-A-001-01
Figure 3. Yoke Bushings (Sheet 1 of 2)
Applicable to: ALL
412-A-62-20-00-00A-685A-B
ECCN EAR99
31 MAY 2023 Page 00056-21
BHT-412-CRO
ICN-412-A-622000-B-97499-00055-A-001-01
Figure 3. Yoke Bushings (Sheet 2 of 2)
412-A-62-20-00-00A-685A-B
Applicable to: ALL
Page 00056-22 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00025-A-001-01
Figure 4. Main Rotor Hub Pitch Horn Assembly - Damage Repair Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-62-20-00-00A-685A-B
ECCN EAR99
31 MAY 2023 Page 00056-23
BHT-412-CRO
ICN-412-A-622000-B-97499-00023-A-001-01
Figure 5. Main Rotor Blade Bolt Assembly - Damage Repair Limits (Sheet 1 of 1)
412-A-62-20-00-00A-685A-B
Applicable to: ALL
Page 00056-24 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-01032-A-001-01
Figure 6. Clevis Assembly — Repair (Sheet 1 of 1)
Applicable to: ALL
412-A-62-20-00-00A-685A-B
ECCN EAR99
31 MAY 2023 Page 00056-25
BHT-412-CRO
ICN-412-A-622000-B-97499-00040-A-001-01
Figure 7. Main Rotor Hub Droop Restraint Components - Damage Repair Limits (Sheet 1 of 5)
412-A-62-20-00-00A-685A-B
Applicable to: ALL
Page 00056-26 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00041-A-001-01
Figure 7. Main Rotor Hub Droop Restraint Components - Damage Repair Limits (Sheet 2 of 5)
Applicable to: ALL
412-A-62-20-00-00A-685A-B
ECCN EAR99
31 MAY 2023 Page 00056-27
BHT-412-CRO
ICN-412-A-622000-B-97499-00042-A-001-01
Figure 7. Main Rotor Hub Droop Restraint Components - Damage Repair Limits (Sheet 3 of 5)
412-A-62-20-00-00A-685A-B
Applicable to: ALL
Page 00056-28 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00043-A-001-01
Figure 7. Main Rotor Hub Droop Restraint Components - Damage Repair Limits (Sheet 4 of 5)
Applicable to: ALL
412-A-62-20-00-00A-685A-B
ECCN EAR99
31 MAY 2023 Page 00056-29
BHT-412-CRO
ICN-412-A-622000-B-97499-00044-A-001-01
Figure 7. Main Rotor Hub Droop Restraint Components - Damage Repair Limits (Sheet 5 of 5)
412-A-62-20-00-00A-685A-B
Applicable to: ALL
Page 00056-30 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Hub - Assembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Locating Pin Assembly
Buildup Bench Assembly
412-210-001-101
T101263-101
1
1
Remarks
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Corrosion preventive compound
Corrosion preventive compound
Zinc chromate primer
Epoxy polyamide primer
Sealant
MEK
Adhesive
Sealant
Adhesion promoter
Lockwire
Abrasive pad
Abrasive cloth or paper
Lockwire
Fabric
Grease
Adhesive
C-101
C-104
C-201
C-204
C-308
C-309
C-317
C-320
C-327
C-405
C-407
C-423
C-447
C-505
C-561
C-562
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
Remarks
Procedure
NOTE
The following overhaul instructions apply to 412-010-100-ALL except where noted in the text.
1.
STEPS
HUB DASH NUMBERS
1 – 10
All hubs
14 – 16
-121
17 – 22
-139, Post BHT-412-SI-21, -145, -151, -159, -171, -175
23 – 34
-181 (1) and -193 (1)
35
All hubs
36
-115, -121, -139, -145, -151, -159, -171
37 – 38
-175, -181 (1) , -193 (1) , -195, -201, -209, -217
39 – 53
All hubs
54 – 58
-139, -145, -151, -159, -171, -175, -181 (1) , -193 (1) ,
-195, -201, -209, -217
59 – 65
-175, -181 (1) , -193 (1)
66
All hubs
NOTE:
1
Helicopters S/N 36020 and subsequent to include S/N 46400 through 46499 and helicopters modified by
412-570-001-103.
Applicable to: ALL
412-A-62-20-00-00A-710A-B
ECCN EAR99
31 MAY 2023 Page 00057-1
BHT-412-CRO
Position the lower cone seat (9, Figure 1, Detail A) on the hub buildup assembly (T101263-101) (Figure 2). Coat the
mating surface with corrosion preventive compound (C-104).
2.
Position the lower yoke assembly (11, Figure 1, Detail A) on the lower cone seat (9). Align the holes.
3.
Coat the mating surfaces with corrosion preventive compound (C-104) and install the splined plate (5) on the lower
yoke with the longer flange down and the lower dowel pin (9A) seated in the yoke.
4.
Position the upper yoke assembly (10) on the splined plate (5) 90° to the lower yoke assembly (11) with the splined
plate upper dowel pin (9A) seated in the upper yoke.
5.
Coat the mating surfaces of eight drive pins (2) with corrosion preventive compound (C-104), and install through the
upper yoke assembly (10), splined plate (5), and lower yoke (11). Tap pins lightly with leather mallet to fully seat.
6.
Apply corrosion preventive compound (C-104) to mating surface of upper cone seat (4) align holes and install
on upper yoke (10).
7.
Apply corrosion preventive compound (C-104) to mating surface of eight bolts (3) and install through assembled
components.
8.
For helicopters Pre TB 412-92-104 and Pre BHT-412-SI-21, install washers (8) and nuts (7). Torque nuts 60 to 70
foot-pounds (82 to 94 Nm) and secure bolts (3) in pairs with lockwire (C-447).
9.
Install fitting (19, Detail D) on yoke as follows:
NOTE
Buffers (21) may be sanded lightly with abrasive cloth or paper (C-423) at edges to facilitate installation
of fitting (19).
9.1.
Coat mating surfaces of fitting (19) with corrosion preventive compound (C-101) and position on yoke.
9.2.
Coat mating surfaces of bolts (20) with corrosion preventive compound (C-101) and install through fitting and yoke.
Install steel washers (22) and nuts (23). Secure nuts with new cotter pins (24).
9.3.
Remaining fitting (19) installations are identical.
10.
For helicopters Post TB 412-03-190 or S/N 36120 and subsequent, install fitting (19, Detail D) on yoke as follows:
NOTE
Buffers (21) may be sanded lightly with abrasive cloth or paper (C-423) at edges to facilitate installation
of fitting (19).
10.1.
Coat mating surfaces of fitting (19) and yoke buffer (21) with a 0.010 to 0.020 inch (0.25 to 0.51 mm) thick coat of
adhesive (C-317) or grease (C-561) and position fitting (19) on yoke.
10.2.
Coat mating surfaces of bolts (114) with corrosion preventive compound (C-101). Do not apply on threads.
10.3.
Attach fitting (19) to yoke with bolts (114), washers (115), washers (116) and nuts (117) through fitting and yoke.
Torque nuts 100 to 140 inch-pounds (11 to 16 Nm). Secure nuts with new cotter pins (118).
10.4.
Coat bolt (114) heads, washers (115), washers (116) and nuts (117) with corrosion preventive compound (C-101).
10.5.
Remove all excess adhesive (C-317) or grease (C-561) squeeze out.
10.6.
Let adhesive (C-317) or grease (C-561) cure for a period of 24 hours at a temperature of 70 to 95°F (21 to 35°C).
10.7.
Remaining fitting (19) installations are identical.
NOTE
If main rotor hub assembly is 412-010-100-195 or -209 and ASB 412-98-92 has been accomplished,
reidentify the data plate and Historical Service Record to 412-010-100-217 and add suffix “FM” after part
dash number to indicate “Field Modified”. Data plate MS27253-1 can be added to assembly, if required.
The serial number of a field modified part number will not be altered or changed.
10.8.
Make an entry in the Helicopter Historical Records (HR) to show that the main rotor hub has been modified as
per TB 412-03-190.
Applicable: Main rotor hub 412-010-100-121:
412-A-62-20-00-00A-710A-B
Applicable to: ALL
Page 00057-2 31 MAY 2023
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BHT-412-CRO
11.
Prepare spindle assembly (18) for installation on yoke assembly as follows:
11.1.
Coat mating surface of pivot bearing (32, Detail H) with epoxy polyamide primer (C-204).
11.2.
Align dowel pins with holes in spindle assembly (18) and press into place while primer is wet. Tap with leather mallet,
if necessary, to fully seat. Apply sealant (C-320) to threads of bolts (34) and install with steel washers (33). Torque
bolts (34) 50 to 70 inch-pounds (6 to 8 Nm). Use same procedures to install remaining pivot bearings.
11.3.
Coat mating surfaces of pitch horn (16) and spindle assembly (18) with zinc chromate primer (C-201).
11.4.
Mount spindle assembly (18, detail C) in a suitable holding fixture.
11.5.
Position pitch horn (16) with pins (15) on spindle assembly (18). Install pins (15), washer (14), and bolt (13). Torque
bolt 425 to 450 foot-pounds (576 to 610 Nm). Secure bolt with lockwire (C-447).
11.6.
Apply a bead of adhesive sealant (C-308) around washer (14), and opposite side of pitch horn (16) and around
spindle (18) shaft.
11.7.
Remove spindle assembly (18) from holding fixture.
11.8.
Remaining spindle assembly pitch horn installs are identical.
12.
Install spindle assembly on yoke assembly as follows:
12.1.
Apply wet epoxy polyamide primer (C-204) to mating surface of fitting (19). Mount spindle assembly to yoke with
dowel pins on pivot bearing (32) seated in holes of fitting (19). Tap spindle with leather mallet to fully seat.
12.2.
Coat mating surfaces of bolts (36) with corrosion preventive compound (C-101) and install with steel washers (35).
Torque bolts (36) 50 to 70 inch-pounds (6 to 8 Nm).
12.3.
Remaining spindle assembly installations are identical.
NOTE
Damper sets are matched by serial number. Ensure serial number integrity is maintained.
13.
Install damper set halves (25 and 37) and damper bridge (27 and 38 or 52) as follows:
13.1.
Assemble damper set halves (25 and 37) and damper bridge (27 and 38). (Refer to Step 45..)
13.2.
Assemble damper set/bridge assembly (27 and 38) and damper bearing (17, Detail E). (Refer Step 37..)
13.3.
Coat mating surface of bolts (30) with corrosion preventive compound (C-101) and install with washers (31) under
head of bolts.
13.4.
Install washers (39) and nuts (40).
13.5.
Coat mating surfaces of bolts (28) withcorrosion preventive compound (C-101) and install with washers (29) under
head of bolts.
13.6.
Install washers (42) and nuts (41).
13.7.
Torque nuts (40) 70 foot-pounds (95 Nm) and nuts (41) 200 inch-pounds (23 Nm).
13.8.
Remaining damper set (27 and 38) installations are identical.
Applicable: Main rotor hub part number 412-010-100-139, Post BHT-412-SI-21, 412-010-100-145, -151, -159, -171 and -175:
14.
Position lower cone seat (12, Detail B) on hub buildup assembly (T101263-101), Figure 2. Coat mating surface with
corrosion preventive compound (C-101)
15.
Position lower yoke assembly (11, Figure 1) on lower cone seat (12). Align holes.
16.
Coat mating surfaces with corrosion preventive compound (C-101) and install splined plate (5) on lower yoke with
longer flange down and lower dowel pin (9A) seated in yoke.
17.
Position upper yoke (10) on splined plate (5) 90° to lower yoke (11) with splined plate upper dowel pin (9A) seated in
upper yoke.
18.
Coat mating surfaces of eight drive pins (2) with corrosion preventive compound (C-101) and install through upper
yoke (10), splined plate (5), and lower yoke (11). Tap pins lightly with leather mallet to fully seat.
Applicable to: ALL
412-A-62-20-00-00A-710A-B
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31 MAY 2023 Page 00057-3
BHT-412-CRO
19.
Apply corrosion preventive compound (C-101) to mating surface of upper cone seat (4) align holes and install
on upper yoke (10).
NOTE
Step 20. through Step 23. are for preparing hub parts to achieve thermal fit between components.
Applicable: Main rotor hubs 412-010-100-181 and subsequent:
20.
Install two locating pins (2, Figure 3) to the lower cone seat. Tighten and hold in place using washers (5) and nuts (6).
21.
Install bolts (59, Figure 1, Detail J) and nuts (60).
22.
Chill drive pins (2, Detail B), lower cone seat (12), splined plate (5) and upper cone seat (4) in dry ice for
approximately 30 minutes.
WHEN HEATING YOKE ASSEMBLIES, ENSURE YOKE BUFFERS (43, 44 AND 45 DETAIL H) DO
NOT EXCEED 180°F (82°C).
23.
Heat upper yoke (10, Detail B) and lower yoke (11) with heat lamps for approximately 30 minutes. Do the following:
NOTE
Step 24. through Step 31. involve interference fit parts and should be accomplished before parts return
to ambient temperature.
24.
Position lower cone seat (12) on (T101263-101) hub buildup assembly (Figure 2). Coat mating surface with corrosion
preventive compound (C-104).
25.
Coat upper yoke and lower yoke (10 and 11, Figure 1, Detail B) mating surfaces with corrosion preventive compound
(C-104).
26.
Position lower yoke assembly (11) on lower cone seat (12) using locating pin assembly (412-210-001-101) as
guides (Figure 3).
27.
Install splined plate (5, Figure 1) on lower yoke assembly (11) with longer flange down and lower dowel pin (9A)
seated in yoke. Splined plate (5) master tooth should align with red blade.
28.
Position upper yoke assembly (10) 90° to lower yoke assembly (11) using locating pin assembly (412-210-001-101)
as guides (Figure 3) with splined plate (5, Figure 1) upper dowel pin (9A) seated in upper yoke (10).
29.
Coat mating surface of eight drive pins (2) with corrosion preventive compound (C-104). Install six drive pins (2)
through upper yoke (10), splined plate (5) and lower yoke (11). Tap pins (2) lightly with leather mallet to fully seat.
30.
Remove two located pin assemblies (412-210-001-101). Install two drive pins (2, Figure 1).
31.
Apply corrosion preventive compound (C-101) to mating surface of upper cone seat (4) align holes and install
on upper yoke (10).
32.
Apply corrosion preventive compound (C-101) to mating surface of eight bolts (3) and install through assembled
components.
33.
Install washers (8) and nuts (7). Torque nut 70 to 80 foot-pounds (95 to 108 Nm) and secure bolt (3) heads in
pairs with lockwire (C-447).
34.
Install fitting (19, Detail D) on yoke as follows:
NOTE
Buffers (21) may be sanded lightly at edges with abrasive cloth or paper (C-423) to facilitate installation
of fitting (19).
34.1.
Coat mating surfaces of fitting (19) with corrosion preventive compound (C-101) and position on yoke.
34.2.
Coat mating surfaces of bolts (20) with corrosion preventive compound (C-101) and install through fitting (19) and
yoke. Install steel washer (22) and nuts (23). Secure nuts with new cotter pin (24).
34.3.
Install remaining fittings using identical procedure.
412-A-62-20-00-00A-710A-B
Applicable to: ALL
Page 00057-4 31 MAY 2023
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BHT-412-CRO
35.
Install pivot bearing (32, Detail H) as follows:
35.1.
Coat mating surface of pivot bearing with epoxy polyamide primer (C-204).
35.2.
Align dowel pins on pivot bearing with holes in spindle assembly (18) and press into place while primer is wet. Tap
with leather mallet to fully seat if necessary.
35.3.
Apply sealant (C-320) to threads of bolts (34, Detail E) and install with steel washers (33). Torque bolts 50 to 70
inch- pounds (6 to 8 Nm).
35.4.
Install remaining pivot bearings using identical procedure.
36.
Install the spindle assembly on the yoke assembly as follows:
36.1.
Apply corrosion preventive compound (C-101) to the mating surface of the fitting (19). Mount the spindle assembly
(18) to the yoke with the dowel pins on the pivot bearing (32) seated in the holes in the fitting. Tap the spindle
with a leather mallet to fully seat.
36.2.
Coat the mating surfaces of the bolts (36) with corrosion preventive compound (C-101) and install with the steel
washers (35). Torque the bolts 50 to 70 inch-pounds (6 to 8 Nm).
36.3.
Install the remaining spindle assemblies using identical procedures.
NOTE
Damper sets are matched by serial number. Make sure serial number integrity is maintained.
NOTE
If any individual lead-lag damper requires replacement, then the complete yoke damper set (four parts)
must be replaced.
37.
Install the damper set halves (25 and 37) and upper and lower damper bridges (27 and 52, Detail H), as follows:
37.1.
Assemble the damper set halves (25 and 37) and upper and lower damper bridges (27 and 38, Detail E).
37.2.
Assemble the damper set/bridge assembly and damper bearing (17).
NOTE
To ensure proper grip length on the bolts (51F), washers AN-960-516L may be substituted for washers
AN-960-516.
38.
Install damper sets halves (51A and 51G) 412-310-146-101 and -103 as follows:
38.1.
Apply corrosion preventive compound (C-104) on the faying surfaces of the bolts (51F, Detail G).
NOTE
Install the bushings (51E) on the bolt head side (inboard). The bushing flange must be installed outside
the clevis on -101 and inside the clevis on -103, as shown on Figure 1, Detail I.
38.2.
Install the damper set halves (51A and 51G) on the damper bearing (51H) on spindle assembly (51B) and secure with
the nuts (51C), washers (51D), bushings (51E), and bolts (51F). Torque the nuts (51C) 100 to 140 inch-pounds (11
to 16 Nm).
NOTE
The following procedures are for 412-010-100, Post TB 412-90-92, BHT-412-CR&O.
39.
Add the shims (26) to the damper set halves (25 and 37) and the upper and lower damper bridges (27 and 38, Detail
E or 27 and 52, Detail H) to obtain dimensional sizes determined in (412-A-62-20-00-00A-280B-B / 00054) and
color code to identify the location.
40.
Final clean the parts as follows:
40.1.
Sand the contact surfaces (Figure 4) between the damper set halves (25 and 37, Figure 1) and damper bearing (17)
in a circular motion with abrasive pad (C-407).
40.2.
Clean the sanded surfaces of all parts with MEK (C-309).
Applicable to: ALL
412-A-62-20-00-00A-710A-B
ECCN EAR99
31 MAY 2023 Page 00057-5
BHT-412-CRO
DO NOT APPLY WAX OR CONTAMINATION OF THE MATING SURFACES OF SPINDLE BEARING
AND DAMPER SET HALVES, BRIDGE, SHIM CAN OCCUR.
41.
Apply adhesion promoter (C-327) to the mating surfaces of the damper bearing (17) and damper set halves (25 and
37). Allow to dry for 15 to 20 minutes at room temperature.
AVOID USING EXCESSIVE AMOUNTS OF ADHESIVE TO PREVENT SQUEEZE-OUT INTO THE
ELASTOMERIC AREA OF DAMPER.
42.
Apply an even coating of adhesive (C-317) approximately 0.010 to 0.020 inch (0.25 to 0.51 mm) thick to the mating
surface of the damper bearing (17) and damper set halves (25 and 37).
43.
Position the trimmed fabric (C-505) on the mating surface of the damper set halves with enough excess material to
extend beyond the outer edges of the mating surface and in the damper bearing recess.
44.
Apply a thin layer of adhesive (C-317) to the faying surfaces of fabric (C-505). Apply adhesive to the piloted bore of
the damper bridge.
45.
Install the required shim (26) in the damper bridges (27 and 52, Detail H) and install the damper set halves (25 and
37) firmly in place in the bridges. Refer to Figure 6 for adhesive.
46.
Assemble the bridge, shim, and damper assembly on the yoke and spindle bearing. Install the bolts (28 and 30,
Figure 1), washers (29 and 31), washers (39 and 42), and nuts (40 and 41). Torque the nuts (40) 70 foot-pounds (95
Nm) and nuts (41) 200 inch-pounds (23 Nm).
47.
Allow adhesive to cure 24 hours at 65 to 85°F (18 to 30°C) to achieve handling strength. Full cure is achieved in 5 to
7 days at 65 to 85°F (18 to 30°C). An alternate cure is by heating for 2 hours at 155 to 165°F (69 to 74°C). Heat cure
is recommended to produce maximum bond strength.
48.
Replace any detail part of the arm and bearing that shows evidence of excessive wear and/or damage.
49.
Coat the mating surfaces of the bolts (30) with corrosion preventive compound (C-101) and install through the damper
bridges with the washers (31) under the head of the bolts.
50.
Install the washers (39) and nuts (40).
51.
Coat the mating surfaces of the bolts (28) with corrosion preventive compound (C-101) and install through the damper
bridges with the washer (29) under the head of the bolts.
52.
Install the washers (42) and nuts (41).
53.
Torque the nuts (40) 70 foot-pounds (95 Nm) and nuts (41) 200 inch-pounds (23 Nm).
54.
Install the remaining damper assemblies using the identical procedure.
55.
Install the pitch horn (16, Detail C) on the spindle assembly (18) as follows:
55.1.
Coat the mating surfaces of the pitch horn (16) and spindle assembly (18) with unreduced zinc chromate primer
(C-201).
55.2.
Position the pitch horn (16) on spindle the assembly (18) as shown. Use the blade bolt lock pin on the spindle to
determine the orientation of the spindle.
55.3.
Insert eight pins (15) into the end of the pitch horn (16).
55.4.
Install the washer (14) and bolt (13). Install the assembly into a suitable holding fixture. Torque the bolt 425 to 450
foot-pounds (577 to 610 Nm) and secure the bolt to the hole in pitch horn with lockwire (C-447). Remove assembly
from fixture.
55.5.
Apply a bead of sealant (C-308) around washer (14), and opposite side of pitch horn (16) around spindle (18) shaft.
55.6.
Install remaining pitch horns using identical procedure.
412-A-62-20-00-00A-710A-B
Applicable to: ALL
Page 00057-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
56.
Assemble droop restraint system as follows:
56.1.
Install nut (63, Detail J) on clevis (64) and screw clevis (64) into clevis assembly (62). Do not lock nut (63) at this time.
56.2.
Install bushing (79) in window of cam (76) and position cam in fork of clevis (64).
56.3.
Position arms (65) on each side of clevis (64) with holes aligned through arms (65) and secure with bolt (67),
washers (66), and nut (78).
56.4.
Align second hole in arms (65) with holes in clevis (64), and install bolts (69) with washers (68).
56.5.
Position weight (72) between arms (65) and install bolt (71) with washers (70) and nut (73).
56.6.
Torque nut (73) 50 to 70 inch-pounds (6 to 8 Nm), and nut (78) 37 to 42 foot-pounds (50 to 57 Nm), and bolts (69) 25
to 35 inch-pounds (3 to 4 Nm).
56.7.
Secure the nut (78) with new cotter pin (80) and the bolts (69) with lockwire (C-405).
56.8.
Assemble remaining droop restraints using identical procedure.
57.
Install droop restraint system to rotor hub as follows:
57.1.
Position cam (76) to lower damper bridge (52) and install two bolts (74) with washers (75).
57.2.
Install two bolts (53) with washers (54) and nuts (77).
57.3.
Torque the bolts (74) 100 to 140 inch-pounds (11 to 16 Nm) and the nuts (77) 25 to 28 foot-pounds (34 to 38 Nm).
57.4.
Install the nut (60) on the bolt (59) and install the bolt in the lug on the lower cone seat (12). Torque the nut 25
to 35 inch-pounds (3 to 4 Nm).
57.5.
Adjust the clevis assembly (62) on the threaded portion of the clevis (64) to facilitate the alignment of the bolt hole
in the clevis assembly with the hole in the lug of the lower cone seat (12). Install the bolt (61) with the washers
(56), thrust washers (57), and nut (55). Torque the nut (55) 60 to 75 foot-pounds (81 to 102 Nm) and the nut (63)
375 to 400 inch-pounds (42 and 45 Nm).
57.6.
Secure the bolts (53, 60, 69, and 74) and the nut (63) with lockwire (C-405). Secure the nuts (55 and 78) with
the new cotter pins (80).
57.7.
Install the remaining droop restraints using the identical procedures.
58.
Rig the droop restraints in accordance with the BHT-412-MM.
59.
Install the blade bolts (81, Detail K) with the washers (82), nuts (83), locks (84), and plugs (85). Do not torque
or lockwire at this time.
60.
If previously disassembled, assemble the expandable blade bolt (1, Figure 7) as follows:
60.1.
Apply a thin continuous layer of grease (C-561) to the core pin (5) and the segments (3) both internally and externally
on all surfaces.
60.2.
Hold the end of the bolt segment removal/ installation workaid and the bolt handle (2).
60.3.
Rotate the expandable bolt assembly to allow segments (3) to slide freely from the removal/ installation workaid back
onto the core pin (5). Make sure the segments seat correctly against each other.
60.4.
Remove the expandable bolt segment removal/installation workaid and install the nut (4) on the core pin (5). The
minimum tare torque for the nut must be 14 inch-pounds (1.58 Nm). If not, replace the nut.
61.
Install and adjust the expandable blade bolt (1, Figure 7) (BHT-412-MM, Chapter 62).
NOTE
The shim (94, Figure 1) is only installed on the pendulum arms 412-010-217-101.
Applicable: Main rotor hubs 412-010-100-151, -159, -171, -175, -181, -193.:
62.
Assemble the shim (94, Detail L) and weight (93) to the arm (100) with the two bolts (90), four washers (89), washers
(88), and two nuts (87). Install the bolt (91) with the two washers (92). Torque the bolt (90) 75 to 95 inch-pounds (9 to
11 Nm) and the bolt (91) 25 to 28 foot-pounds (34 to 38 Nm). Secure the bolts (90 and 91) with lockwire (C-405).
Applicable to: ALL
412-A-62-20-00-00A-710A-B
ECCN EAR99
31 MAY 2023 Page 00057-7
BHT-412-CRO
NOTE
Pay particular attention to hardware stack-up. Shims (96) and washers (95) look the same in appearance.
Make sure you install them at the correct location.
NOTE
The assembly procedures are identical for either side of the arm.
63.
Assemble the bearings (99), washers (95), shims (96), and retainers (97) to each side of the inner race (101).
64.
Install the inner race (101), and the assembled detail parts in the arm (100), and secure each side with the retaining
rings (98).
65.
Check for a 0.005 inch (0.13 mm) (Figure 9) maximum clearance (two places) between the retaining ring (98,
Figure 1) and the retainer (97).
66.
If the clearance is not within limits, reshim in accordance with Figure 9.
NOTE
Make sure the head of the bolt (103, Figure 1) is oriented in the direction of rotation of the main rotor.
NOTE
If the nut (105) touches the shank of the bolt (103) after application of the torque, it is permitted to add
one washer (109) NAS1149E0863P between the nut and the washer (104).
67.
After obtaining proper clearance, install the arm (100, Detail L) in the bracket (107) and attach with the bolt (103),
washers (102 and 104 (109 is optional)), and nut (105). Torque the nut 24 to 34 foot-pounds (33 to 46 Nm). Secure
the nut with a new cotter pin (106).
68.
Install the arm and bearing assembly (112, Detail M) as follows:
68.1.
Place the arm and bearing assembly (112) on the hub assembly. Line up the bolt holes.
68.2.
Install the bolts (110), washers (111), and nuts (113). Torque the nuts 29 to 33 foot-pounds (39 to 44 Nm).
68.3.
Install the remaining arm and bearing assemblies using the identical procedures.
69.
Install the color markings (Figure 8)
412-A-62-20-00-00A-710A-B
Applicable to: ALL
Page 00057-8 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00002-A-001-01
Figure 1. Main Rotor Hub Assembly (Sheet 1 of 9)
Applicable to: ALL
412-A-62-20-00-00A-710A-B
ECCN EAR99
31 MAY 2023 Page 00057-9
BHT-412-CRO
ICN-412-A-622000-B-97499-00003-A-001-01
Figure 1. Main Rotor Hub Assembly (Sheet 2 of 9)
412-A-62-20-00-00A-710A-B
Applicable to: ALL
Page 00057-10 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00004-A-001-01
Figure 1. Main Rotor Hub Assembly (Sheet 3 of 9)
Applicable to: ALL
412-A-62-20-00-00A-710A-B
ECCN EAR99
31 MAY 2023 Page 00057-11
BHT-412-CRO
ICN-412-A-622000-B-97499-00005-A-001-01
Figure 1. Main Rotor Hub Assembly (Sheet 4 of 9)
412-A-62-20-00-00A-710A-B
Applicable to: ALL
Page 00057-12 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00006-A-001-01
Figure 1. Main Rotor Hub Assembly (Sheet 5 of 9)
Applicable to: ALL
412-A-62-20-00-00A-710A-B
ECCN EAR99
31 MAY 2023 Page 00057-13
BHT-412-CRO
ICN-412-A-622000-B-97499-00007-A-001-01
Figure 1. Main Rotor Hub Assembly (Sheet 6 of 9)
412-A-62-20-00-00A-710A-B
Applicable to: ALL
Page 00057-14 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00008-A-001-01
Figure 1. Main Rotor Hub Assembly (Sheet 7 of 9)
Applicable to: ALL
412-A-62-20-00-00A-710A-B
ECCN EAR99
31 MAY 2023 Page 00057-15
BHT-412-CRO
ICN-412-A-622000-B-97499-00009-A-001-01
Figure 1. Main Rotor Hub Assembly (Sheet 8 of 9)
412-A-62-20-00-00A-710A-B
Applicable to: ALL
Page 00057-16 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00010-A-001-01
Figure 1. Main Rotor Hub Assembly (Sheet 9 of 9)
Applicable to: ALL
412-A-62-20-00-00A-710A-B
ECCN EAR99
31 MAY 2023 Page 00057-17
BHT-412-CRO
ICN-412-A-622000-B-97499-00001-A-001-01
Figure 2. Main Rotor Hub Buildup Assembly - Tool Application (T101263-101) (Sheet 1 of 1)
412-A-62-20-00-00A-710A-B
Applicable to: ALL
Page 00057-18 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00057-A-001-01
Figure 3. Locating Pin Assembly (412-210-001-101) (Sheet 1 of 1)
Applicable to: ALL
412-A-62-20-00-00A-710A-B
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31 MAY 2023 Page 00057-19
BHT-412-CRO
ICN-412-A-622000-B-97499-00058-A-001-01
Figure 4. Surface Preparation - Damper Set/Damper Bearing (Sheet 1 of 1)
412-A-62-20-00-00A-710A-B
Applicable to: ALL
Page 00057-20 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00059-A-001-01
Figure 5. Fabric Application to Dampers (Sheet 1 of 1)
Applicable to: ALL
412-A-62-20-00-00A-710A-B
ECCN EAR99
31 MAY 2023 Page 00057-21
BHT-412-CRO
ICN-412-A-622000-B-97499-00056-A-001-01
Figure 6. Damper Bridge and Bearing Adhesive Application (Sheet 1 of 1)
412-A-62-20-00-00A-710A-B
Applicable to: ALL
Page 00057-22 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00011-A-001-01
Figure 7. Expandable Blade Bolt - Disassembly (Sheet 1 of 2)
Applicable to: ALL
412-A-62-20-00-00A-710A-B
ECCN EAR99
31 MAY 2023 Page 00057-23
BHT-412-CRO
ICN-412-A-622000-B-97499-00012-A-001-01
Figure 7. Expandable Blade Bolt - Disassembly (Sheet 2 of 2)
412-A-62-20-00-00A-710A-B
Applicable to: ALL
Page 00057-24 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00061-A-001-01
Figure 8. Main Rotor Hub Color Markings (Typical) (Sheet 1 of 1)
Applicable to: ALL
412-A-62-20-00-00A-710A-B
ECCN EAR99
31 MAY 2023 Page 00057-25
BHT-412-CRO
ICN-412-A-622000-B-97499-00060-A-001-01
Figure 9. Arm and Bearing Assembly Shimming Requirements (Sheet 1 of 1)
412-A-62-20-00-00A-710A-B
Applicable to: ALL
Page 00057-26 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Blade - Cleaning
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Tapping Hammer (Steel)
T75449-2
1
Remarks
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Drycleaning solvent
Aliphatic naphtha
Cleaning compound
Clean cloth
C-304
C-305
C-318
C-516
AR
AR
AR
AR
Remarks
Procedure
1.
Wipe the main rotor blade with a clean cloth (C-516) moistened with aliphatic naphtha (C-305) or drycleaning
solvent (C-304).
2.
Wash blades with a mild solution of cleaning compound (C-318) and water. Rinse blades with clean water and
wipe dry with clean cloths.
Applicable to: ALL
412-A-62-10-00-00A-258A-B
ECCN EAR99
31 MAY 2023 Page 00058-1
BHT-412-CRO
Intentionally blank page
412-A-62-10-00-00A-258A-B
Applicable to: ALL
Page 00058-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Blade - Conditional Inspection
Procedure
1.
NOTE
If records or physical appearance of main rotor blade indicate that the blade has been subjected to an
accident, incident, or usage outside the realm of normal usage, perform conditional inspection. Refer to
BHT-412-MM, Chapter 5 for definition of accidents or incidents which require that conditional inspection
be conducted and detailed inspection procedures for each condition. If main rotor blade does not require
conditional inspection, proceed with normal inspection (412-A-62-10-00-00A-280B-B / 00060).
Applicable to: ALL
412-A-62-10-00-00A-284A-B
ECCN EAR99
31 MAY 2023 Page 00059-1
BHT-412-CRO
Intentionally blank page
412-A-62-10-00-00A-284A-B
Applicable to: ALL
Page 00059-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Blade - Normal Inspection
Procedure
THE INSPECTION CRITERIA DEFINING ACCEPTABLE OR REJECTABLE DEFECTS IN THIS
MANUAL ARE INTENDED TO BE USED AS A GENERAL GUIDE. IT IS VIRTUALLY IMPOSSIBLE
TO DESCRIBE ALL DEFECTS THAT COULD OCCUR ON A ROTOR BLADE. EXCEPT IN
CASES WHERE BLADES FALL INTO OBVIOUS SCRAP CATEGORY, BHT PRODUCT SUPPORT
DEPARTMENT SHOULD BE CONSULTED PRIOR TO SCRAPPING BLADE. IN SOME CASES,
LIMITS SPECIFIED CAN BE EXCEEDED IN CERTAIN AREAS AND POSSIBLE REPAIRS CAN BE
DEVISED BY MUTUAL AGREEMENT OF BELL HELICOPTER TEXTRON AND USER.
1.
Inspect leading edge abrasion strip (3, Figure 1) and splice covers (4 and 10) as follows:
1.1.
Return main rotor blade to Bell for replacement of leading edge strip under the following conditions:
1.1.1.
Leading edge deformation due to abrasion
1.1.2.
Edge voids deeper than 0.50 inch (12.7 mm).
1.1.3.
Holes, cracks or tears.
1.2.
Nicks, scratches, or sharp dents not exceeding 0.012 inch (0.30 mm) are acceptable if polished smooth. Non-sharp
dents not exceeding 0.015 inch (0.38 mm) are acceptable.
2.
Inspect blade bolt retention bushings (1) for corrosion, pitting, elongation, and size.
2.1.
Inside diameter not to exceed 1.2525 inches (31.814 mm).
2.2.
Corrosion or pitting of either bushing in excess of replacement dimension 1.2525 inches (31.814 mm) after polishing,
is cause for removal. Polishing in small local areas exceeding replacement diameter shall not exceed 20% of
the inside diameter surface area.
3.
Inspect the fretting pads (9) for cracks and adhesive voids. If cracks are found or edge voids are in excess of 0.25 inch
(6.4 mm), notify Product Support Engineering. Reference 412-A-62-10-00-00A-685A-B / 00061 for repair procedures.
4.
Inspect sealant applied in balance pocket area, on root end weight cover (18, View D) and it’s attaching hardware
(19, 20 and 21) for gaps, cracks, voids, deterioration, erosion and signs of water ingression. If sealant is
damaged and/or there is presence of rust stains, indicating water ingress and corrosion of weights, refer to
412-A-62-10-00-00A-685A-B / 00061, step 17 for limitation and authorized repair.
5.
Inspect the inboard, center, and outboard trim tabs (6, 7, and 8) for damage, debonding, cracking, or corrosion.
6.
Inspect the main rotor blade bonded assembly (2) as follows:
6.1.
Inspect for cracks. If cracks are found, notify Product Support Engineering.
6.2.
Nicks, scratches, gouges, or dents on the fiberglass surfaces are acceptable without repair provided they do not break
the fibers or cause delamination. If fibers are broken or delaminations develop, refer to 412-A-62-10-00-00A-685A-B /
00061.
6.3.
Scratches, gouges, or nicks that penetrate one or more layers of skin, but do not damage the core, may be repaired
(412-A-62-10-00-00A-685A-B / 00061).
6.4.
Holes in the skin outboard of station 90.0 may be repaired (412-A-62-10-00-00A-685A-B / 00061).
6.5.
Nicks or notches in the extreme trailing edge of the blade that are less than 0.120 inch (3.05 mm) in depth, are
acceptable if polished out over a distance of at least 2.0 inches (51 mm) each side of the nick or notch.
6.6.
Nicks or scratches in the erosion shield (11, Detail A) are acceptable provided they do not penetrate. Excessive
damage will require erosion shield replacement at Bell. Repairable damage to erosion shield may be repaired per
erosion shield repair procedures in 412-A-62-10-00-00A-685A-B / 00061.
Applicable to: ALL
412-A-62-10-00-00A-280B-B
ECCN EAR99
31 MAY 2023 Page 00060-1
BHT-412-CRO
NOTE
A void is defined as any unbonded area. Many subdefinitions of voids are often used, such as lack
of adhesive, gas pocket, misfit, etc. This manual makes no distinction among these subdefinitions,
but groups them under the general term, void. Inspect for voids using a small steel tapping hammer
(T75449-2), or equivalent, on all surfaces.
7.
Inspect for voids under the abrasion strips (3) as follows:
NOTE
Blades 412-015-200 may have either two or three abrasion strips. Blades 412-015-300 have two abrasion
strips.
7.1.
Single voids shall not exceed 25.0 square inches (16,129 mm2) in area and shall not exceed a chordwise width of
1.50 inches (38.1 mm). Voids within 1.0 inch (25 mm) of each other shall be considered a single void.
7.2.
On blades with three abrasion strips, the total area of voids shall not exceed 40.0 square inches (25806 mm2) on
the inboard strip, 35.0 square inches (22581 mm2) on the center strip, and 40.0 square inches (25806 mm2) on
the outboard strip.
7.3.
On blades with two abrasion strips, the total area of voids shall not exceed 60.0 square inches (38710 mm2) on the
inboard strip and 25.0 square inches (16129 mm2) on the outboard strip.
7.4.
Edge voids are not allowed if connected to internal voids larger than 10.0 square inches (6452 mm2). Edge voids not
greater than 0.25 inch (6.4 mm) depth and not closer than 0.50 inch (12.7 mm) to an allowable internal void must be
repaired per 412-A-62-10-00-00A-685A-B / 00061. Edge voids beyond these limits are not allowed.
7.5.
It is permissible at the butt end of the inboard abrasion strip to have a void up to 2.0 inches (51 mm) wide around the
leading edge and up to 12.0 inches (305 mm) long spanwise. The limits of Step 7.4. apply except at the extreme butt
end of the strip where the void may be present at the edge but must be sealed with a non-silicon flexible sealant.
NOTE
Acceptable voids shall not be within 0.38 inch (9.7 mm) of edge of skin.
7.6.
Voids in toe of inboard abrasion strip less than 9.0 inches (229 mm) long spanwise or is cracked as in Figure 1 Sheet
4 may be repaired per abrasion strip repair procedures 412-A-62-10-00-00A-685A-B / 00061.
8.
Inspect for voids under skin of blade bonded assembly (2) as follows:
8.1.
Voids between skins and trailing edge strip (13, Section B-B) in excess of 1/4 of the chordwise width of mating
surfaces and 20.0 inches (508 mm) in length are not acceptable.’Total area of voids per side shall not exceed
5.0 square inches (3226 mm2).
8.2.
Single voids between upper or lower skin (12 or 14, Section B-B) and core (14) exceeding 5.0 square inches (3226
mm2) in area and 1.0 inch (25 mm) chordwise width are not acceptable. Total area of voids exceeding 10.0 square
inches (6452 mm2) per side is not acceptable. Delaminations between skin plies are not acceptable.
8.3.
Voids between upper or lower skin (12 or 14) and spar (16) exceeding 1/4 of the chordwise width of mating surfaces
and 15.0 inches (381 mm) in length are not acceptable. Total area of voids exceeding 20.0 square inches (12903
mm2) is not acceptable.
9.
Inspect paint condition. Refer to 412-A-62-10-00-00A-685A-B / 00061 for refinish procedures.
10.
Inspect main rotor blade bonded assembly (2, Figure 1) tooling key areas as follows:
NOTE
The main rotor blade bonded assembly (2) has three cut-outs on the upper surface directly aft of the
abrasion strip (3) approximately 3.5 inches (89 mm) aft of the blade leading edge. These three cut-outs
hold tooling keys used during blade manufacturing. The rectangular tooling keys are removed or
machined flush after assembly is bonded. The cavities are filled with fiberglass and aerodynamic filler
to obtain a smooth surface.
10.1.
Inspect the filler material in the tooling key areas for cracks or voids at the following locations:
10.1.1.
Between Station 107.7 and 112.31, cavity width 0.79 inch (20.1 mm).
10.1.2.
Between Station 147.7 and 152.31, cavity width 0.49 inch (12.4 mm).
412-A-62-10-00-00A-280B-B
Applicable to: ALL
Page 00060-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
10.1.3.
Between Station 188.7 and 193.31, cavity width 0.46 inch (11.7 mm).
NOTE
All three tooling key cavities are 4.61 inches (117.1 mm) long and 0.028 inch (0.71 mm) deep.
10.2.
If you find cracks or voids, repair as per (412-A-62-10-00-00A-685A-B / 00061).
Applicable to: ALL
412-A-62-10-00-00A-280B-B
ECCN EAR99
31 MAY 2023 Page 00060-3
BHT-412-CRO
ICN-412-A-621000-B-97499-00001-A-001-01
Figure 1. Main Rotor Blade (Sheet 1 of 5)
412-A-62-10-00-00A-280B-B
Applicable to: ALL
Page 00060-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-621000-B-97499-00002-A-001-01
Figure 1. Main Rotor Blade (Sheet 2 of 5)
Applicable to: ALL
412-A-62-10-00-00A-280B-B
ECCN EAR99
31 MAY 2023 Page 00060-5
BHT-412-CRO
ICN-412-A-621000-B-97499-01083-A-001-01
Figure 1. Main Rotor Blade (Sheet 3 of 5)
412-A-62-10-00-00A-280B-B
Applicable to: ALL
Page 00060-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-621000-B-97499-01084-A-001-01
Figure 1. Main Rotor Blade (Sheet 4 of 5)
Applicable to: ALL
412-A-62-10-00-00A-280B-B
ECCN EAR99
31 MAY 2023 Page 00060-7
BHT-412-CRO
ICN-412-A-621000-B-97499-01085-A-001-01
Figure 1. Main Rotor Blade (Sheet 5 of 5)
412-A-62-10-00-00A-280B-B
Applicable to: ALL
Page 00060-8 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Blade - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Chemical film material
Epoxy polyamide primer
Primer
Polyurethane coating
Aliphatic naphtha
Sealant
Adhesive
Cleaning compound
Fairing compound
Denatured alcohol
Ethyl alcohol
Cleaner
Adhesive
Abrasive cloth or paper
Abrasive pad
Steel wool
Abrasive cloth or paper
Masking tape
Cheesecloth
Clean cloth
C-100
C-204
C-234
C-245
C-305
C-308
C-317
C-318
C-323
C-326
C-339
C-344
C-363
C-406
C-407
C-411
C-423
C-426
C-486
C-516
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
Remarks
Procedure
1.
Polish out all acceptable nicks and scratches on abrasion strip (3, Figure 1), using 180 grit or finer abrasive cloth or
paper (C-423). Polish to a surface finish of 32 Roughness, Height, Rating (RHR) or better, removing only enough
material to remove the nicks or scratches. steel wool (C-411) may be used on the abrasion strips to polish out
defect. Acceptable dents need not be filled or faired.
2.
Remove corrosion from blade bolt retention bushings (1) with fine grade abrasive cloth or paper (C-423). After
corrosion removal, hole diameter must not exceed limits of 412-A-62-10-00-00A-280B-B / 00060.
3.
Polish out all acceptable nicks and scratches on fiberglass surfaces and erosion shield (10) with 200 grit abrasive
cloth or paper (C-423). Lightly abrade painted surfaces immediately surrounding polished areas.
4.
Polish out nicks, scratches, and notches in trailing edge strip (12) which do not extend forward more than 0.20 inch (5.1
mm) with 200 grit or finer abrasive cloth or paper (C-423). Fair repair out a minimum of 2.0 inches (51 mm) each side.
5.
Repair all acceptable edge voids by injecting or flowing adhesive (C-363). Ensure entire void is filled and smooth
to surrounding surface. Allow adhesive to cure for 24 hours at room temperature or 2 hours at 155 to 165°F (69
to 74°C). Apply heat locally and do not exceed maximum temperature. Heat cure is recommended to produce
maximum bond strength.
Applicable to: ALL
412-A-62-10-00-00A-685A-B
ECCN EAR99
31 MAY 2023 Page 00061-1
BHT-412-CRO
NOTE
Use the following criteria to select appropriate repair procedures for damage to main rotor blade fiberglass
skins and core.
If fiberglass fibers are broken, but core is not damaged, or core damage is limited to less than 1.0 square
inch (645 mm2), repair in accordance with 412-A-62-10-00-00A-280B-B / 00060, step 6.
Damage passing though both skins with core damage less than 1.0 square inch (645 mm2) may be
repaired by applying a skin patch to both top and bottom sides in accordance with Step 6..
Damage to the core in excess of 1.0 square inch (645 mm2) but which can be enclosed within a 3.0 inches
(76 mm) diameter circle may be repaired in accordance with Step 7.. Damage of this type which passes
completely through the blade shall be repaired by installing core patches from both top and bottom sides
of blade. Install larger diameter patch first (Figure 2).
Contact Product Support Engineering for repair of damage in excess of that previously stated.
6.
Apply a patch to the damaged skins with no core damage or core damage limited to 1.0 square inch (645 mm2)
as follows:
NOTE
Patches shall cover damage by 1.0 inch (25 mm) minimum in all directions and be circular in shape.
Damage is limited to 3.0 inches (76 mm) and patch is limited to 5.0 inches (127 mm) in diameter.
6.1.
Remove finish from blade approximately 3.0 inches (76 mm) around damage by sanding with 180 grit or finer
abrasive cloth or paper (C-423).
6.2.
Hand sand with 200 grit abrasive cloth or paper (C-423) approximately 3.0 inches (76 mm) in diameter, larger and
centered around damage, to remove high areas and primer from skim.
NOTE
Outer surface of patch material is marked with part number and arrow for direction of installation.
6.3.
Select proper skin patch material (Figure 3). Trim to a diameter 2.0 inches (51 mm) larger than damaged area.
Remove peel ply and thoroughly abrade inner surface of patch with 180 grit abrasive cloth or paper (C-423).
6.4.
Wipe sanded area on skin and skin patch material with a clean cloth (C-516) moistened with ethyl alcohol (C-339).
Repeat with successive clean cloths and alcohol until the cloth remains clean after wiping. Wipe dry with a final
clean cloth (C-516).
6.5.
Apply adhesive (C-317), 3 parts A to 1 part B to patch surface and mating surface of blade. Spread adhesive
thoroughly using spatula, tongue depressor, or other appropriate workaid to achieve complete wetting of surfaces.
Use sufficient adhesive to fill low areas.
6.6.
Apply patch, centered over damaged area, with arrow on outer surface pointed in outboard direction. Tape patch in
position with two strips of masking tape (C-426).
6.7.
Allow adhesive to cure for 24 hours at room temperature, or for 2 hours at 155 to 165°F (69 to 74°C). Apply heat locally
only, and do not exceed maximum temperature. Heat cure is recommended to produce maximum bond strength.
6.8.
Smooth fillet of adhesive around patch with 180 grit abrasive cloth or paper (C-423).
6.9.
Refinish after all repairs have been completed. Refer to Step 10..
7.
Apply a patch to the damaged skins with excessive core damage as follows:
NOTE
Patch shall cover damage by 1.0 inch (25 mm) minimum in all directions and be circular in shape. Damage
is limited to 3.0 inches (76 mm) and patch is limited to 5.0 inches (127 mm). If double skin core patch
is required, install larger diameter and depth core patch first. See Figure 2 for typical double skid/core
patch.
7.1.
Remove finish from blade approximately 3.0 inches (76 mm) around damage. Use clean cloth (C-516) moistened
with ethyl alcohol (C-339).
7.2.
Use a circle template and mark a circle around the damage. Hand sand, with 200 grit abrasive cloth or paper (C-423)
approximately 2.0 inches (51 mm) around outside of circle to remove primer.
7.3.
Cut through skin around circle using hole saw or router cutter. Peel damaged skin from core.
412-A-62-10-00-00A-685A-B
Applicable to: ALL
Page 00061-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
NOTE
Select core patch from Figure 3. Core patch should be thick enough to eliminate all damage or extend
more than half way through the blade so that remaining damage can be repaired from opposite side
of blade. Core patches are provided with a thin layer of fiberglass bonded to one side, which will be
bonded to the end cells at the bottom of the cutout area. Core patches may be stacked to provide different
thicknesses. Check core thickness at trailing edge side of hole to determine maximum thickness of core
patch to install.
7.4.
Insert end mill in a router. Set depth of cutter to match thickness of core patch selected.
7.5.
Rout out core within skin cutout following contour of blade to ensure that cutout is uniform depth. Remove sanding
and routing dust from blade.
7.6.
Cut a circular core patch from selected core patch material that will fit hole loosely (approximately 1/16 (0.0625) inch
(1.588 mm) gap all around). Abrade fiberglass surface of core patch with 180 grit abrasive cloth or paper (C-423).
NOTE
Outer surface of skin patch material is marked with part number and arrow for direction of installation.
7.7.
Obtain skin patch material (299-015-008-101) and trim to a diameter 2.0 inches (51 mm) larger than hole. Remove
peel-ply and thoroughly abrade inner surface of patch with 180 grit abrasive cloth or paper (C-423).
7.8.
Wipe sanded area of core patch and skin patch material with a clean cloth (C-516) moistened with ethyl alcohol
(C-339). Repeat with successive clean cloths and alcohol until the cloth remains clean after wiping. Wipe dry
with final clean cloth.
7.9.
Apply adhesive (C-317) to the fiberglass side of the core patch and around circumference of patch and hole. Insert
core patch into hole.
7.10.
Apply adhesive (C-317) to skin patch surface and mating surface of blade skin. Do not apply adhesive to cell ends of
core patch. Spread adhesive around to ensure complete wetting of contact surfaces.
7.11.
Apply skin patch, centered over hole with outer surface arrow pointed outboard. Tape patch in position with two
pieces of masking tape (C-426).
7.12.
Allow adhesive to cure for 24 hours at room temperature or for 2 hours at 155 to 165°F (69 to 74°C). Apply heat locally
only and do not exceed maximum temperature. Heat cure is recommended to produce maximum bond strength.
7.13.
Smooth fillet of adhesive around patch with 180 grit abrasive cloth or paper (C-423).
7.14.
Refinish after all repairs have been completed. Refer to Step 15..
8.
Repair fretting pads as follows:
8.1.
All edge voids shall be filled with adhesive (C-363).
USE EXTREME CARE NOT TO DAMAGE COMPOSITE SPAR DURING DRILLING OPERATION.
8.2.
Voids less than 2.5 square inches (1613 mm2), drill a 0.07 inch (1.8 mm) diameter hole at each end of void and
inject void with adhesive (C-363).
8.3.
Apply clamp pressure to fretting pad and cure adhesive for 24 hours at 70 to 80°F (21 to 27°C) or for one hour at
140 to 160°F (60 to 71°C).
9.
Replace inboard trim tab (8, Figure 1), center trim tab (16), or outboard trim tab (6) as follows:
NOTE
Trim tab replacement will be required if cracked, debonded, bent, or dented to an extent it cannot be
straightened.
9.1.
Mask off 1.0 inch (25 mm) around perimeter of trim tab to be replaced.
9.2.
Remove paint in masked off area with 150 grit abrasive cloth or paper (C-423) or finer. Sand in spanwise direction.
Do not sand through outer ply of glass fabric.
Applicable to: ALL
412-A-62-10-00-00A-685A-B
ECCN EAR99
31 MAY 2023 Page 00061-3
BHT-412-CRO
USE EXTREME CARE WHEN PEELING OFF TAB TO PREVENT TEARING OR SEPARATING PLIES
OF FIBERGLASS SKIN.
9.3.
Remove old trim tab by cutting tab off approximately 1/8 (0.125) inch (3.18 mm) beyond blade trailing edge. Peel
tab spanwise, starting at a corner, one side at a time.
9.4.
Sand off all loose adhesive with 180 grit abrasive cloth or paper (C-423) and wipe with clean cloth. All old adhesive
need not be removed unless contaminated.
9.5.
Obtain proper part number trim tab for position being replaced. Remove peel-ply from trim tab mating surfaces and
lightly abrade with 120 to 180 grit abrasive cloth or paper (C-423). Dry wipe sanded surfaces with clean cloth
and inspect for uniform abrading.
9.6.
Wipe sanded surface of blade and trim tab with a clean cloth dampened with ethyl alcohol (C-339). Repeat with
successive clean cloths and denatured alcohol until cloth remains clean after wiping. Wipe dry with a final clean cloth.
9.7.
Mix adhesive (C-317) per adhesive manufacturers instructions. Apply adhesive to inside mating surfaces of trim tab
and mating surfaces of blade. Spread adhesive around to assure complete wetting of contact surfaces.
9.8.
Position trim tab as far forward on blade as it will travel. Move tab slightly back and forth to expel air pockets.
Wipe off excessive adhesive and fair fillet around tab.
9.9.
Apply contact to 5 psi (34.48 kPa) pressure to tab using wooden blocks and clamps or any other suitable means.
9.10.
Cure adhesive for 24 hours at room temperature or two hours at 155 to 165°F (69 to 74°C). Apply heat locally only
and do not exceed maximum temperature. Heat cure is recommended to produce maximum bond strength.
9.11.
Refinish after all repairs are completed. Refer to Step 12..
10.
Repair erosion shield (11, Figure 1)as follows:
USE EXTREME CARE NOT TO DAMAGE SKIN DURING DRILLING OPERATION.
10.1.
Voids between erosion shield and skin drill a 0.07 inch (1.8 mm) diameter hole at each end of void and inject void with
adhesive (C-363).
10.2.
Apply pressure to erosion shield and cure adhesive for 24 hours at 70 to 80°F (21 to 27°C) or for one hour at 140
to 160°F (60 to 71°C)..
10.3.
Refinish after all repairs are completed. Refer to Step 15..
11.
Repair closure and fairing as follows:
NOTE
The voids between closures, fairings and blade may be injected with adhesive (C-363) or adhesive
(C-317).
11.1.
Sand closure or fairing to remove paint 1.0 inch (25 mm) past damaged area with 150 grit sandpaper.
11.2.
Wipe area completely clean using a cloth dampened with denatured alcohol (C-326). Wipe dry with a clean cloth.
11.3.
Install a three ply wet layup of No. 120 glass cloth and adhesive (C-363) to cover defective area plus 0.75 inch
(19.1 mm) all around.
11.4.
Refinish after all repairs are completed. Refer to Step 15..
12.
Replacement of estane erosion shield as follows:
USE EXTREME CARE NOT TO DAMAGE COMPOSITE SPAR WHILE REMOVING SHIELD.
412-A-62-10-00-00A-685A-B
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12.1.
Remove old estane erosion shield by peeling strips off of blade. If strip tears, stretches or will not peel, use scraper.
EXCESSIVE SANDING WILL DAMAGE SPAR.
12.2.
Sand off all adhesive with 180 grit abrasive cloth or paper (C-423).
12.3.
Wipe area completely clean using a cloth dampened with denatured alcohol (C-326). Wipe dry with a clean dry cloth.
12.4.
Sand estane erosion shield with 80 grit abrasive cloth or paper (C-423).
12.5.
Wipe area completely clean using a cloth dampened with denatured alcohol (C-326). Wipe dry with a clean dry cloth.
12.6.
Apply adhesive (C-363) to mating surfaces of erosion shield and spar.
12.7.
Position erosion shield on blade and tape in place. Apply 10 psi (68.9 kPa) pressure to erosion shield bonding.
12.8.
Apply 10 psi (68.9 kPa) pressure to erosion shield and cure adhesive for 24 hours at 70 to 80°F (21 to 27°C)..
12.9.
Refinish after all repairs are completed. Refer to Step 15..
13.
Repair abrasion strip (3, Figure 1).
13.1.
Repair of voids in toe of inboard abrasion strip less than 4.25 inches (107.9 mm) per Figure 1.
13.1.1.
Lift toe of abrasion strip and clean with denatured alcohol (C-326). Sand mating surface with 180 grit abrasive
cloth or paper (C-423) blow off all sanding residue and wipe the area with a clean cloth dampened with denatured
alcohol (C-326).
13.1.2.
Apply adhesive (C-317) to mating surfaces and apply pressure to bonding area with a vacuum bag or clamps.
13.1.3.
Cure adhesive for 24 hours at 70 to 80°F (21 to 27°C) or for one hour at 140 to 160°F (60 to 71°C).
13.1.4.
Smooth fillet of adhesive around abrasion strip with 180 grit abrasive cloth or paper (C-423) and refinish locally
as required .
13.1.5.
Refinish after all repairs are completed. Refer to Step 15..
13.2.
Repair of voids in toe of inboard abrasion strip larger than 4.25 inches (107.9 mm) per Figure 1.
13.2.1.
Remove splice cover (4), being careful not to damage blade and repair void using procedures listed above for
repairing a void.
13.2.2.
Clean off all old adhesive, paint and other contaminates from abrasion strips at splice in area to receive cover. Use
100 grit or finer abrasive cloth or paper (C-423), sanding in a spanwise direction.
13.2.3.
Wipe area completely clean using a cloth dampened with denatured alcohol (C-326). Wipe dry with a clean cloth.
13.2.4.
Obtain a new splice cover assembly. Remove peel ply from inside cover and lightly sand cured adhesive. Wipe with a
clean cloth to remove residue.
13.2.5.
Apply adhesive (C-317) to inside of cover and blade surface. Rub adhesive around on blade and cover to assure
complete 'wetting' of contact surface.
13.2.6.
Position inboard splice cover (4) on blade with outboard most part of the splice cover at blade station 182.21.
Move splice cover back and forth slightly to expel any air pockets. Wipe off excessive adhesive. Fair in edges
to cover with adhesive (C-317).
13.2.7.
Hold cover in place with heavy rubber bands, bungee cords, or vacuum.
13.2.8.
Cure the adhesive for 24 hours at 70 to 80°F (21 to 27°C) or for one hour at 140 to 160°F (60 to 71°C).
13.2.9.
Smooth a fillet of adhesive around the splice cover with 180 grit abrasive cloth or paper (C-423) and refinish locally,
as required.
13.2.10.
Refinish after all the repairs are completed. Refer to Step 15..
13.3.
Repair a crack in the toe of the inboard abrasion strip that is less than 6.0 inches (152 mm), as follows (Figure 1):
Applicable to: ALL
412-A-62-10-00-00A-685A-B
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31 MAY 2023 Page 00061-5
BHT-412-CRO
EXTREME CARE MUST BE USED TO ENSURE COMPOSITE SPAR IS NOT DAMAGED DURING
TRIMMING OPERATIONS.
13.3.1.
To remove crack in the abrasion strip, trim to a smooth radius.
13.3.2.
Clean the spar area with 180 grit abrasive cloth or paper (C-423). Remove all sanding residue and wipe with a
clean cloth, moistened with denatured alcohol (C-326).
13.3.3.
Fill the area of the missing abrasion strip with 120 and 181 glass cloth adhesive (C-317) to the contour of the blade.
13.3.4.
Cure the adhesive for 24 hours at 70 to 80°F (21 to 27°C) or for one hour at 140 to 160°F (60 to 71°C).
13.3.5.
Sand to smooth the area with abrasive cloth or paper (C-423) and refinish locally, as required.
13.3.6.
Refinish after all the repairs are completed. Refer to Step 15..
14.
Replace the abrasion strip splice cover (10, Figure 1), as follows:
USE CARE NOT TO DAMAGE THE ABRASION STRIP OR THE BLADE WHEN REMOVING THE
SPLICE COVER.
14.1.
Remove the worn or damaged splice cover by prying loose. Use care to prevent damage to the abrasion strip or blade.
14.2.
Remove all old adhesive, paint, and other contaminants from the abrasion strips at the splice. Use 100 grit or finer
abrasive cloth or paper (C-423). Sand in spanwise direction.
14.3.
Wipe the sanded area with a clean cloth (C-516) moistened with ethyl alcohol (C-339). Dry with a clean dry cloth.
14.4.
Remove the peel-ply from the inside new splice cover. Lightly abrade the cured adhesive with 120 to 180 grit abrasive
cloth or paper (C-423). Wipe with a clean cloth to remove residue.
14.5.
Wipe the sanded surface of the abrasion strip and splice cover with a clean cloth, moistened with ethyl alcohol
(C-339). Repeat with successive clean cloths and alcohol until the cloth remains clean after wiping. Wipe dry
with a final clean cloth.
14.6.
Mix adhesive (C-317) per manufacturers instructions. Apply adhesive to the inside mating surface of the splice cover
and to the mating surface of the abrasion strip splice. Agitate adhesive on both surfaces thoroughly to ensure
complete wetting.
14.7.
Position the outboard splice cover (10) at blade station 276.00 (Detail A) to match the contour. Move cover back and
forth slightly to expel air pockets. Wipe off excessive adhesive. Fair in edges to cover with adhesive (C-317).
14.8.
Secure the splice cover in place with heavy rubber bands or bungee cords.
14.9.
Allow adhesive to cure for 24 hours at room temperature or for 2 hours at 155 to 165°F (69 to 74°C). Apply heat locally
only and do not exceed maximum temperature. Heat cure is recommended to produce maximum bond strength.
14.10.
Refinish after all repairs are completed. Refer to Step 15..
15.
Touch-up refinish repaired areas as follows:
NOTE
Main rotor blade must have all acceptable defects repaired before continuing.
15.1.
Wash refinished areas by scrubbing with abrasive pad (C-407) and cleaning compound (C-318). Achieve water break
free surface, which will be evident by continuous unbroken film of water on surface after thoroughly rinsing.
NOTE
From completion of following step through final paint, repaired or refinished surfaces of blades should not
be handled with bare hands.
15.2.
Treat stainless steel surfaces (abrasion strip and splice cover) with cleaner (C-344). Apply with a brush or swab.
Allow solution to remain on the surface 1 to 3 minutes. Rinse thoroughly and allow to air dry.
412-A-62-10-00-00A-685A-B
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15.3.
Treat aluminum and titanium surfaces with chemical film material (C-100). Refer to the BHT-ALL-SPM, Standard
Practices Manual for application procedures.
15.4.
Mask off the serial number plates and the leading edge and bushing holes.
15.5.
Wipe the surface with a tack rag.
NOTE
Do not paint abrasion strip.
15.6.
Apply one spray coat of epoxy polyamide epoxy polyamide primer (C-204) or primer (C-234) to repaired areas. Allow
1 hour minimum to 8 hours maximum drying time before the application of topcoats. The dry film thickness of
one coat shall be 0.4 to 1.0 mils.
15.7.
Apply one spray coat of urethane compatible epoxy polyamide epoxy polyamide primer (C-204) or primer (C-234)
to repaired areas. Allow 1 hour minimum to 8 hours maximum drying time before the application of topcoats. The
dry film thickness of one coat shall be 0.4 to 1.0 mils.
Applicable: SN: 33001-Subsequent:
15.8.
Apply two coats of polyurethane coating (C-245) color as desired. Allow a minimum of 1 hour to a maximum of 8
hours air dry between successive coats. Sand between coats as required for aerodynamic smoothness. The dry film
thickness of one coat of urethane shall be 0.8 to 1.2 mils.
Applicable: SN: 46400-46499:
15.9.
Apply two coats of polyurethane coating (C-245) lusterless black color 37038. Allow a minimum of 1 hour to
a maximum of 8 hours air dry between successive coats. Sand between coats as required for aerodynamic
smoothness. The dry film thickness of one coat of urethane shall be 0.8 to 1.2 mils.
15.10.
Paint the blade on the upper and lower surfaces to match the existing scheme with two coats of polyurethane coating
(C-245) orange-yellow color No. 13538.
16.
Repair cracks and voids in the filler material of main rotor blade bonded assembly (2) tooling key areas as follows:
NOTE
Refer to 412-A-62-10-00-00A-280B-B / 00060 for location of tooling key areas.
16.1.
Apply masking tape (C-426) 0.50 inch (12.7 mm) outside of the perimeter of the tooling key cavity.
SAND MAIN ROTOR BLADE SKIN IN A SPANWISE DIRECTION ONLY.
16.2.
Remove the paint and primer by sanding with 180-grit or smoother abrasive cloth or paper (C-406) in a spanwise
direction only.
16.3.
Remove any loose filler material from the tooling key cavity by sanding with 180-grit or smoother abrasive cloth
or paper (C-406) .
16.4.
Clean the sanded area with a cheesecloth (C-486) dampened with ethyl alcohol (C-339) and wipe dry with a clean
cloth.
16.5.
Remove the masking tape from the perimeter of the tooling key cavity.
16.6.
Apply fairing compound (C-323) to the tooling key cavity area. Smooth out compound and let cure for 24 hours at
room temperature.
SAND MAIN ROTOR BLADE SKIN IN A SPANWISE DIRECTION ONLY.
16.7.
Once the fairing compound (C-323) has cured, sand excess compound material smooth with a 250-grit or smoother
abrasive cloth or paper (C-406) in a spanwise direction only.
16.8.
Refinish after all repairs are completed. Refer to Step 15..
Applicable to: ALL
412-A-62-10-00-00A-685A-B
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31 MAY 2023 Page 00061-7
BHT-412-CRO
17.
Replace sealant if there are gaps, cracks, voids, deterioration or erosion in balance pocket area at root end weight
cover (18,Figure 1, View D) and/or its attaching hardware but no signs of water ingress, as follows:
17.1.
Use plastic scrapper and remove all old sealant on and around cover (18) and/or hardware.
17.2.
Use clean cloth (C-516) moist with aliphatic naphtha (C-305) and wipe area inside balance pocket clean.
17.3.
Apply sealant (C-308) all around cover (18) outer edge and/or all around hardware (screws (21), nut (19) and
washer (20)). Make sure there are no gaps, voids or openings between sealant and parts, to prevent ingress of
water or moisture.
18.
If you find signs of water ingression in balance pocket, disassemble and repair/replace parts as follows:
18.1.
Use plastic scrapper and remove all sealant on and around cover (18) and hardware (screws (21), nut (19) and
washer (20)).
18.2.
Remove screws (21), nut (19) and washer (20) from cover (18) and stud (17).
USE CARE NOT TO DAMAGE STUD WHEN REMOVING COVER. THE COVER IS ALSO SEALED
INSIDE BALANCE POCKET.
18.3.
Insert curved heavy gage metal rod or two jacking screws into cover (18) screw holes (holes from screws (21)) and
carefully pry/pull out cover (18) off stud (17) and out from balance pocket.
NOTE
Record quantity and order of parts removed, to assist at reinstallation.
18.4.
Remove nut (22), nut (23), washer (24), weight(s) (25), washer(s) (26), washer(s) (27), retainer (28), weight(s) (29),
weight(s) (30) and weight (31) from stud (17) and out of balance pocket.
18.5.
Clean and check screws (21), nut (19), washer (20), nut (22), nut (23), washer (24), weight(s) (25), washer(s) (26) and
washer(s) (27) for thread damage, wear, corrosion and deformation. If part(s) is/ are damaged beyond acceptable
limits, refer to BHT-412-IPB-1 for part replacement part number(s).
18.6.
Check retainer (28), weight(s) (29), weight(s) (30) and weight (31) for damage as per limits that follow:
NOTE
If part is damaged beyond limits and part number is no longer legible, refer to Figure 1, View F, to get part
details that will assist in identifying part.
18.6.1.
The weight/retainer (28, 29, 30, 31, View E) retention hole is permitted to have 0.250 inch (6.35 mm) diameter
maximum wear.
18.6.1.1. Clean corrosion off weight/retainer with Scotch-Brite pad to specified limits.
18.6.1.2. Apply coat of epoxy polyamide primer (C-204) to weight/retainer surfaces and allow to air dry before installation.
18.6.1.3. If part is damaged beyond limits, refer to BHT-412-IPB-1 for part replacement part number and replace damaged
part with new part.
18.6.2.
The weight/retainer (28, 29, 30, 31, View E) retention outer hole area is permitted to have 0.750 inch (19.05 mm)
diameter maximum superficial corrosion only.
18.6.2.1. Clean corrosion off weight/retainer with Scotch-Brite pad to specified limits.
18.6.2.2. Apply coat of epoxy polyamide epoxy polyamide primer (C-204) to weight/retainer surfaces and allow to air dry
before installation.
18.6.2.3. If part is damaged beyond limits, refer to BHT-412-IPB-1 for part replacement part number and replace damaged
part with new part.
18.6.3.
The weight/retainer (28, 29, 30, 31, View E) face surface is permitted to have 0.020 inch (0.51 mm) corrosion damage.
18.6.3.1. Clean corrosion off weight/retainer with Scotch-Brite pad to specified limits.
412-A-62-10-00-00A-685A-B
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BHT-412-CRO
18.6.3.2. Apply coat of epoxy polyamideepoxy polyamide primer (C-204) to weight/retainer surfaces and allow to air dry
before installation.
18.6.3.3. If part is damaged beyond limits, refer to BHT-412-IPB-1 for part replacement part number and replace damaged
part with new part.
18.7.
Check stud (17) for corrosion damage. Only superficial corrosion that can be removed with Scotch-Brite pad is
permitted. If damage is beyond limits, contact Product Support Engineering (PSE) .
18.8.
Clean balance pocket area from all debris and old sealant with clean cloth (C-516) moist with aliphatic naphtha
(C-305).
MAKE SURE PARTS ARE INSTALLED IN CORRECT ORIENTATION, WHEN REINSTALLING BACK
INTO BALANCE POCKET.
BLADES ARE FACTORY BALANCED, ONLY INSTALL PARTS THAT WERE REMOVED. YOU CAN
REPLACE PARTS THAT DID NOT MEET DAMAGE LIMITS WITH NEW SAME PART NUMBER PARTS,
BUT YOU CANNOT ADD NEW PARTS.
NOTE
Reinstall parts in same order and same quantity as removed in Step 18.4., above.
18.9.
Install weight (31), weight(s) (30), weight(s) (29), retainer (28), washer(s) (27), washer(s) (26), weight(s) (25) onto
stud (17) inside balance pocket and attach with washer (24) and nut (23). Torque nut (23) 20 to 40 inch-pounds
(2.26 to 4.51 Nm).
NOTE
Nut (22) acts as a positioning backstop for cover (18).
18.10.
Install nut (22) onto stud (17) part way down and temporarily install cover (18) until it reaches nut (22). The final
cover (18) position is set when cover face is flush with balance pocket face surface. Remove cover (18) and adjust
nut (22) until necessary dimension is obtained. Mark position of nut (22) inside balance pocket just over nut (22)
surface and on stud (17).
18.11.
Apply bead of sealant (C-308) to area just above nut (22) marked position, all around wall surface inside of balance
pocket.
18.12.
Install cover (18) onto stud (17) and into cavity of balance pocket so that it sits on nut (22) and cover face is flush with
pocket face surface and secure with washer (20) and nut (19). Torque nut (19) 10 to 20 inch-pounds (1.13 to 2.25 Nm).
NOTE
Screws (21) do not attach cover (18) to balance pocket structure. These screw holes are just used for
jackscrews to aid with removal of cover (18).
18.13.
Apply a bead of sealant (C-308) under head of screws (21) and install screws (21) into cover (18). Torque screws
(21) 5 to 10 inch-pounds (0.56 to 1.12 Nm).
18.14.
Apply sealant (C-308) all around cover (18) outer edge, screws (21), nut (19) and washer (20), inside of balance
pocket. Make sure there are no gaps, voids or openings between sealant and parts, to prevent ingress of water
or moisture.
Applicable to: ALL
412-A-62-10-00-00A-685A-B
ECCN EAR99
31 MAY 2023 Page 00061-9
BHT-412-CRO
ICN-412-A-621000-B-97499-00001-A-001-01
Figure 1. Main Rotor Blade (Sheet 1 of 5)
412-A-62-10-00-00A-685A-B
Applicable to: ALL
Page 00061-10 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-621000-B-97499-00002-A-001-01
Figure 1. Main Rotor Blade (Sheet 2 of 5)
Applicable to: ALL
412-A-62-10-00-00A-685A-B
ECCN EAR99
31 MAY 2023 Page 00061-11
BHT-412-CRO
ICN-412-A-621000-B-97499-01083-A-001-01
Figure 1. Main Rotor Blade (Sheet 3 of 5)
412-A-62-10-00-00A-685A-B
Applicable to: ALL
Page 00061-12 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-621000-B-97499-01084-A-001-01
Figure 1. Main Rotor Blade (Sheet 4 of 5)
Applicable to: ALL
412-A-62-10-00-00A-685A-B
ECCN EAR99
31 MAY 2023 Page 00061-13
BHT-412-CRO
ICN-412-A-621000-B-97499-01085-A-001-01
Figure 1. Main Rotor Blade (Sheet 5 of 5)
412-A-62-10-00-00A-685A-B
Applicable to: ALL
Page 00061-14 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-621000-B-97499-00004-A-001-01
Figure 2. Main Rotor Blade Skin and Core Repair (Sheet 1 of 1)
Applicable to: ALL
412-A-62-10-00-00A-685A-B
ECCN EAR99
31 MAY 2023 Page 00061-15
BHT-412-CRO
ICN-412-A-621000-B-97499-00003-A-001-01
Figure 3. Main Rotor Blade Repair Materials (Sheet 1 of 1)
412-A-62-10-00-00A-685A-B
Applicable to: ALL
Page 00061-16 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Blade - Insert (MS124695) Replacement
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Screw
Drill
Tap
10-32 UNF-3A
No. 13/64
10-32
1
1
1
Remarks
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Adhesive
Denatured alcohol
Adhesive
Glass fabric
C-317
C-326
C-363
C-560
AR
AR
AR
AR
Remarks
Procedure
NOTE
A maximum of three inserts per pocket can be repaired.
1.
Remove the damaged inserts (2, Figure 1).
2.
Flush the insert hole with denatured alcohol (C-326). Turn the blade over to allow the excess to run out of the hole.
3.
Allow to dry for 30 minutes.
4.
Repair the hole of the insert (2) as follows:
4.1.
Cut the glass fabric (C-560) approximately 0.06 inch (1.5 mm) long.
4.2.
Fill the hole with a mixture of glass fabric (C-560) and adhesive (C-363).
4.3.
Allow adhesive to cure for 24 hours at 70 to 80°F (21 to 27°C) or for one hour at 140 to 160°F (60 to 71°C).
4.4.
Drill the holes of the aft pocket to a maximum depth of 0.360 inch (9.14 mm) and for the forward pocket to a maximum
depth of 0.320 inch (8.13 mm) with a drill (No. 13/64).
4.5.
Thread the insert holes for a tap (10-32) insert.
4.6.
Countersink 100° X 0.280 to 0.290 inch (100° X 7.11 to 7.37 mm) diameter. Locate the hole position with the
appropriate pocket cover.
4.7.
Remove the chips from the hole.
4.8.
Install the insert (MS124695) with adhesive (C-317). Remove excess adhesive.
4.9.
Install a waxed screw (10-32 UNF-3A) into the insert. Do not torque.
4.10.
Allow adhesive to cure for 24 hours at 70 to 80°F (21 to 27°C) or for one hour at 140 to 160°F (60 to 71°C).
4.11.
Remove the waxed screw installed.
4.12.
Reinstall the pocket cover per the BHT-412-MM, Chapter 18.
Applicable to: ALL
412-A-62-10-00-00A-921A-B
ECCN EAR99
31 MAY 2023 Page 00062-1
BHT-412-CRO
ICN-412-A-621000-B-97499-00005-A-001-01
Figure 1. Main Rotor Blade - Insert (MS124695) Replacement (Sheet 1 of 2)
412-A-62-10-00-00A-921A-B
Applicable to: ALL
Page 00062-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-621000-B-97499-00006-A-001-01
Figure 1. Main Rotor Blade - Insert (MS124695) Replacement (Sheet 2 of 2)
Applicable to: ALL
412-A-62-10-00-00A-921A-B
ECCN EAR99
31 MAY 2023 Page 00062-3
BHT-412-CRO
Intentionally blank page
412-A-62-10-00-00A-921A-B
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Page 00062-4 31 MAY 2023
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BHT-412-CRO
Main Rotor Blade - Erosion Shield Replacement
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Isopropyl alcohol
Abrasive pad
Abrasive cloth or paper
Clean cloth
Adhesive promoter
C-285
C-407
C-423
C-516
C-558
AR
AR
AR
AR
AR
Remarks
Procedure
DO NOT USE A STEEL SCRAPER OR SHARP KNIFE TO REMOVE THE OLD EROSION STRIP.
DAMAGE TO THE UNDERSIDE FIBERGLASS SURFACE MAY OCCUR.
1.
Remove the old erosion shield (32, Figure 1). A plastic scraper or equivalent may be used as required.
2.
Remove the remaining adhesive from the main rotor blade with 180 grit abrasive cloth or paper (C-423). Remove
sanding residue with a clean cloth (C-516) moistened with isopropyl alcohol (C-285). Repeat cleaning operation with
a clean cloth (C-516) and isopropyl alcohol (C-285) until the cloth remains clean.
3.
On the main rotor blade, remove gloss from the paint finish with a 220 grit abrasive cloth or paper (C-423) or abrasive
pad (C-407). Clean the area with a clean cloth (C-516) moistened with isopropyl alcohol (C-285). Wipe dry with a
clean cloth. Allow to dry.
4.
Apply a thin coat of adhesive promoter (C-558) on reworked area with a brush. Let the promoter dry for 10 minutes.
5.
Apply erosion shield (32) equally on the upper and lower surface of the main rotor blade.
6.
Particular attention is required to prevent trapping air under the erosion shield (32). Air bubbles may be punctured in
the aft portion with a pin or hypodermic needle. Press out with a squeegee or thumb toward the puncture.
7.
Allow the erosion shield (32) to cure for 24 hours. If air bubbles are present, repeat Step 6..
8.
Make an entry in the helicopter Historical Records (HR) to show that the remaining rotor blade has been modified as
per TB 412-02-182.
Applicable to: ALL
412-A-62-10-00-05A-921A-B
ECCN EAR99
31 MAY 2023 Page 00063-1
BHT-412-CRO
ICN-412-A-621000-B-97499-00001-A-001-01
Figure 1. Main Rotor Blade (Sheet 1 of 5)
412-A-62-10-00-05A-921A-B
Applicable to: ALL
Page 00063-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-621000-B-97499-00002-A-001-01
Figure 1. Main Rotor Blade (Sheet 2 of 5)
Applicable to: ALL
412-A-62-10-00-05A-921A-B
ECCN EAR99
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BHT-412-CRO
ICN-412-A-621000-B-97499-01083-A-001-01
Figure 1. Main Rotor Blade (Sheet 3 of 5)
412-A-62-10-00-05A-921A-B
Applicable to: ALL
Page 00063-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-621000-B-97499-01084-A-001-01
Figure 1. Main Rotor Blade (Sheet 4 of 5)
Applicable to: ALL
412-A-62-10-00-05A-921A-B
ECCN EAR99
31 MAY 2023 Page 00063-5
BHT-412-CRO
ICN-412-A-621000-B-97499-01085-A-001-01
Figure 1. Main Rotor Blade (Sheet 5 of 5)
412-A-62-10-00-05A-921A-B
Applicable to: ALL
Page 00063-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Hub and Sleeve Assembly (412-010-401-105, -107, -109, -111, -113, -115, and -117)
- Disassembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Staking Tool
Bar
Bearing Ram
Ram Adapter
Support
Wrench
RST2128
T101424
T101262-119
T101382
T101369
T101392
1
1
1
1
1
1
Remarks
Procedure
1.
Refer to the mandatory airworthiness limitations schedule in the BHT-412-MM, Chapter 4 for airworthiness life on
rotating controls components. Identify the components that have accumulated hours for retirement.
2.
For the main rotor hub and sleeve 412-010-401-105 and -107, do as follows:
2.1.
Cut and remove the lockwire from the bolt (2, Figure 1).
2.2.
Remove the cotter pin (8, Detail A), bolts (2 and 3), washers (1, 4, and 6), and nut (7) and separate the link assembly
(10) and anti-torque bushing (5) from the rephasing lever (9). Discard the cotter pin.
2.3.
Remove the remaining link assemblies using the same procedures.
3.
For the main rotor hub and sleeve 412-010-401-109, -111, -113, -115, and -117, do as follows:
3.1.
Remove the cotter pin (8, Detail A), bolt (3), washers (4 and 6), and nut (7) and separate the link assembly (10),
bracket (5B), and bushings (5A and 5C) from the rephasing lever (9). Discard the cotter pin.
3.2.
Use the same procedure to remove the remaining link assembly.
4.
Remove the cotter pins (13 and 21), bolts (11 and 17, Detail B), washers (12, 15, 16, 18, 19 for -105 only, 23, 24,
and 28), nuts (14 and 22) and separate the drive link (27) with the spacers (20 and 25) from the rephasing lever
(9). Discard the cotter pins (13 and 21).
5.
Remove the cotter pin (40), bolt (37, Detail C), washers (36 and 38), nut (39), shaft (33) and separate the rephasing
lever from the hub (49). Discard the cotter pins. Repeat the procedure to remove the remaining rephasing levers.
NOTE
The drive plate set (57, Detail D) was removed during removal of hub and sleeve assembly.
6.
If not previously done when the hub and sleeve assembly was removed (BHT-412-MM, Chapter 62), do a spline wear
check as follows:
6.1.
Install the collective pitch drive plate set (57, Detail D) on a known serviceable mast (BHT-412-MM, Chapter 62).
6.2.
Refer to the inspection of the hub and sleeve assembly (BHT-412-MM, Chapter 62) and do a spline wear check of
the drive plate set (57).
7.
Remove the bolts (42, Figure 1, Detail D), washers (43 and 50), nuts (51), and remove the flange (58), plate set
(57), and shim (56).
8.
Tap the hub assembly (49) lightly with a soft mallet and slide downward off of the sleeve (48).
9.
Remove the lower hub seal (47) from the hub (49). Discard the seal.
10.
Remove the shoulder ring (52) and upper seal (53). Discard the seal.
11.
Remove the bearings (31 and 34) and spacer (32) from the hub (49) using the bearing ram (T101262-119) (Figure 2).
Repeat the procedures for the removal of the remaining bearings and spacers.
Applicable to: ALL
412-A-62-20-00-02A-530A-B
ECCN EAR99
14 NOV 2023 Page 00064-1
BHT-412-CRO
12.
Remove the pin (55) from the nut (54).
NOTE
The nut (54) is designed with left-hand threads.
13.
Install the wrench (T101392) on the nut (54). Insert the bar (T101424) through the holes in the lower end of the sleeve
(48). Hold the bar and remove the nut (54) (Figure 3).
THE SERIAL NUMBERS OF THE BEARING COMPONENTS MUST BE THE SAME. BEARING
COMPONENTS ARE A MATCHED SET. INSTALLATION OF A COMPONENT FROM ANOTHER SET
WILL RESULT IN INCORRECT OPERATION.
14.
Use a support (T101369) and ram adapter (T101382) (Figure 4) to remove the bearing sets (44 and 46, Figure 1,
Detail D) with the spacer set (45) from the sleeve (48) .
412-A-62-20-00-02A-530A-B
Applicable to: ALL
Page 00064-2 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00062-A-002-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 1 of 5)
Applicable to: ALL
412-A-62-20-00-02A-530A-B
ECCN EAR99
14 NOV 2023 Page 00064-3
BHT-412-CRO
ICN-412-A-622000-B-97499-00063-A-001-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 2 of 5)
412-A-62-20-00-02A-530A-B
Applicable to: ALL
Page 00064-4 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00064-A-001-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 3 of 5)
Applicable to: ALL
412-A-62-20-00-02A-530A-B
ECCN EAR99
14 NOV 2023 Page 00064-5
BHT-412-CRO
ICN-412-A-622000-B-97499-00065-A-001-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 4 of 5)
412-A-62-20-00-02A-530A-B
Applicable to: ALL
Page 00064-6 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00066-A-001-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 5 of 5)
Applicable to: ALL
412-A-62-20-00-02A-530A-B
ECCN EAR99
14 NOV 2023 Page 00064-7
BHT-412-CRO
ICN-412-A-622000-B-97499-00067-A-001-01
Figure 2. Bearing Ram (T101262-119) - Tool Application (Sheet 1 of 2)
412-A-62-20-00-02A-530A-B
Applicable to: ALL
Page 00064-8 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00068-A-001-01
Figure 2. Bearing Ram (T101262-119) - Tool Application (Sheet 2 of 2)
Applicable to: ALL
412-A-62-20-00-02A-530A-B
ECCN EAR99
14 NOV 2023 Page 00064-9
BHT-412-CRO
ICN-412-A-622000-B-97499-00069-A-001-01
Figure 3. Tool Application - Wrench (T101392) and Bar (T101424) (Sheet 1 of 1)
412-A-62-20-00-02A-530A-B
Applicable to: ALL
Page 00064-10 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00070-A-001-01
Figure 4. Tool Application - Support (T101369) and Ram Adapter (T101382) (Sheet 1 of 1)
Applicable to: ALL
412-A-62-20-00-02A-530A-B
ECCN EAR99
14 NOV 2023 Page 00064-11
BHT-412-CRO
Intentionally blank page
412-A-62-20-00-02A-530A-B
Applicable to: ALL
Page 00064-12 14 NOV 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Hub and Sleeve Assembly (412-010-401-105, -107, -109, -111, -113, -115, and -117) Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Corrosion preventive oil
Drycleaning solvent
MEK
Barrier material
Barrier tape
C-126
C-304
C-309
C-427
C-456
AR
AR
AR
AR
AR
Remarks
Procedure
1.
Clean all parts fully with drycleaning solvent (C-304). Dry with filtered compressed air.
2.
Clean old adhesive residue from the hub (49, Figure 1, Detail D) with a soft cloth moistened with MEK (C-309).
3.
Remove acrylic lacquer finish from the parts that the magnetic particle inspection is necessary. Remove all organic
finish from the parts that the fluorescent penetrant inspection is necessary. Refer to the BHT-ALL-SPM, Standard
Practices Manual for the procedure to remove paint.
4.
When parts are not to be processed immediately after cleaning, apply corrosion preventive oil (C-126) to all parts to
prevent against corrosion. Put the parts in barrier material (C-427) and attach with barrier tape (C-456).
Applicable to: ALL
412-A-62-20-00-02A-258A-B
ECCN EAR99
14 NOV 2023 Page 00065-1
BHT-412-CRO
ICN-412-A-622000-B-97499-00062-A-002-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 1 of 5)
412-A-62-20-00-02A-258A-B
Applicable to: ALL
Page 00065-2 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00063-A-001-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 2 of 5)
Applicable to: ALL
412-A-62-20-00-02A-258A-B
ECCN EAR99
14 NOV 2023 Page 00065-3
BHT-412-CRO
ICN-412-A-622000-B-97499-00064-A-001-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 3 of 5)
412-A-62-20-00-02A-258A-B
Applicable to: ALL
Page 00065-4 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00065-A-001-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 4 of 5)
Applicable to: ALL
412-A-62-20-00-02A-258A-B
ECCN EAR99
14 NOV 2023 Page 00065-5
BHT-412-CRO
ICN-412-A-622000-B-97499-00066-A-001-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 5 of 5)
412-A-62-20-00-02A-258A-B
Applicable to: ALL
Page 00065-6 14 NOV 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Hub and Sleeve Assembly (412-010-401-105, -107, -109, -111, -113, -115, and -117) Inspection
Procedure
1.
NOTE
If records or physical appearance indicate that the hub and sleeve assembly has been subjected
to an accident or incident, perform a conditional inspection, 412-A-62-20-00-02A-284A-B / 00067.
If the assembly does not require a conditional inspection, accomplish a normal inspection,
412-A-62-20-00-02A-280B-B / 00068. Refer to the BHT-412-MM, Chapter 5 for the definition of accidents
or incidents that require that a conditional inspection be conducted.
Applicable to: ALL
412-A-62-20-00-02A-280A-B
ECCN EAR99
31 MAY 2023 Page 00066-1
BHT-412-CRO
Intentionally blank page
412-A-62-20-00-02A-280A-B
Applicable to: ALL
Page 00066-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Hub and Sleeve Assembly (412-010-401-105, -107, -109, -111, -113, -115, and -117) Conditional Inspection
Procedure
1.
Carefully inspect the assembled component visually for any apparent damage or abnormal appearance. Obvious
defects, which are cause to scrap the entire assembly, are as follows:
1.1.
Severe bind in any of the pivot joints.
1.2.
Severe bind between the hub and sleeve.
2.
Any detail part within the hub and sleeve assembly that has sustained surface damage is subject to surface damage
inspection, as outlined in 412-A-62-20-00-02A-280B-B / 00068. If surface damage exceeds the limits, scrap only
the damaged part.
3.
An unworn bolt must fit freely through the bushings in the drive link. Any binding is cause to scrap the drive link.
4.
With a straight edge, check the cylindrical portion of the collective sleeve for deformation. Warpage in excess of
0.001 inch (0.03 mm) per 1.0 inch (25 mm) is cause to scrap the sleeve.
5.
With a straight edge, check all machined flat surfaces surrounding the lugs, holes, and bushings in the entire
assembly for deformation. Deviations from flat in excess of 0.002 inch (0.05 mm) per 1.0 inch (25 mm) is cause
to scrap only the damaged part.
6.
Accomplish the normal inspection (412-A-62-20-00-02A-280B-B / 00068).
Applicable to: ALL
412-A-62-20-00-02A-284A-B
ECCN EAR99
31 MAY 2023 Page 00067-1
BHT-412-CRO
Intentionally blank page
412-A-62-20-00-02A-284A-B
Applicable to: ALL
Page 00067-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Hub and Sleeve Assembly (412-010-401-105, -107, -109, -111, -113, -115, and -117)
- Normal Inspection
Procedure
1.
Examine the bearing set (44 and 46, Figure 1, Detail D) and spacer set (45) as follows:
1.1.
Examine the bearings for roughness and brinelling. Any brinelling visible under a 5X magnifying glass or of sufficient
depth to cause roughness when the bearing is rotated, is cause for rejection of the bearing.
1.2.
Examine for galled or flaked area on the balls and raceways under a strong light. Examine for broken or fractured
remains.
1.3.
Examine the spacer set (45) for damage and corrosion.
2.
Examine the bearings (29 and 30, Detail B, 31 and 34, Detail C) for smooth operation. Examine the rollers for
looseness due to wear, flaked or flat spots, pitting, or scoring. Examine the seals for damage.
3.
Examine the spacers (20 and 25, Detail B) and washers (18, 19, 24 and 28). If other than a smooth, unscored
surface is found, replace parts as required.
4.
Examine the spacer (32, Detail C), shaft (33), and washers (35 and 41) for cracks, corrosion, and wear.
5.
Examine the flange (58, Detail D), shoulder ring (52), and pin (55) for damage or deformation.
6.
Examine the nut (54) visually for damage or deformation as per 412-A-62-20-00-02A-353A-B / 00069.
Applicable: Main rotor hub and sleeve 412-010-401-105 and -107:
7.
Examine the anti-torque bushing (5, Detail A) for damage, deformation, or worn serrations.
Applicable: Main rotor hub and sleeve 412-010-401-109, -111, -113, -115, and -117:
8.
Examine the bushings (5A and 5C) for damage, wear, or deformation. Examine the bracket (5B, Detail A) per Figure 8.
9.
Examine the hub assembly (49, Figure 1, Detail D) per Figure 2 and 412-A-62-20-00-02A-353A-B / 00069.
10.
Examine the collective sleeve (48, Figure 1, Detail D) per Figure 3 and 412-A-62-20-00-02A-353A-B / 00069.
11.
Examine the drive link assembly (27, Figure 1, Detail B) per Figure 4 and 412-A-62-20-00-02A-353A-B / 00069.
12.
Examine the swashplate link assembly (10, Figure 1, Detail A) per Figure 5 and 412-A-62-20-00-02A-353A-B /
00069. Visually examine for internal corrosion of tube.
13.
Examine the rephasing lever assembly (9, Figure 1, Detail A) per Figure 6 and 412-A-62-20-00-02A-353A-B / 00069.
14.
Examine the bushings (41A, 41B, 41C, Figure 1, Detail C) for wear, damage, or deformation.
15.
Examine the collective drive plate set (57, Figure 1, Detail D) per Figure 7 and 412-A-62-20-00-02A-353A-B / 00069.
Applicable to: ALL
412-A-62-20-00-02A-280B-B
ECCN EAR99
14 NOV 2023 Page 00068-1
BHT-412-CRO
ICN-412-A-622000-B-97499-00062-A-002-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 1 of 5)
412-A-62-20-00-02A-280B-B
Applicable to: ALL
Page 00068-2 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00063-A-001-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 2 of 5)
Applicable to: ALL
412-A-62-20-00-02A-280B-B
ECCN EAR99
14 NOV 2023 Page 00068-3
BHT-412-CRO
ICN-412-A-622000-B-97499-00064-A-001-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 3 of 5)
412-A-62-20-00-02A-280B-B
Applicable to: ALL
Page 00068-4 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00065-A-001-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 4 of 5)
Applicable to: ALL
412-A-62-20-00-02A-280B-B
ECCN EAR99
14 NOV 2023 Page 00068-5
BHT-412-CRO
ICN-412-A-622000-B-97499-00066-A-001-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 5 of 5)
412-A-62-20-00-02A-280B-B
Applicable to: ALL
Page 00068-6 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00071-A-001-01
Figure 2. Collective Sleeve Hub Assembly - Damage Repair Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-62-20-00-02A-280B-B
ECCN EAR99
14 NOV 2023 Page 00068-7
BHT-412-CRO
ICN-412-A-622000-B-97499-00072-A-001-01
Figure 3. Collective Sleeve - Damage Repair Limits (Sheet 1 of 2)
412-A-62-20-00-02A-280B-B
Applicable to: ALL
Page 00068-8 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00073-A-001-01
Figure 3. Collective Sleeve - Damage Repair Limits (Sheet 2 of 2)
Applicable to: ALL
412-A-62-20-00-02A-280B-B
ECCN EAR99
14 NOV 2023 Page 00068-9
BHT-412-CRO
ICN-412-A-622000-B-97499-00074-A-001-01
Figure 4. Drive Link Assembly - Damage Repair Limits (Sheet 1 of 1)
412-A-62-20-00-02A-280B-B
Applicable to: ALL
Page 00068-10 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00075-A-001-01
Figure 5. Swashplate Link Assembly - Damage Repair Limits (Sheet 1 of 2)
Applicable to: ALL
412-A-62-20-00-02A-280B-B
ECCN EAR99
14 NOV 2023 Page 00068-11
BHT-412-CRO
ICN-412-A-622000-B-97499-00076-A-001-01
Figure 5. Swashplate Link Assembly - Damage Repair Limits (Sheet 2 of 2)
412-A-62-20-00-02A-280B-B
Applicable to: ALL
Page 00068-12 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00077-A-001-01
Figure 6. Rephasing Lever Assembly - Damage Repair Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-62-20-00-02A-280B-B
ECCN EAR99
14 NOV 2023 Page 00068-13
BHT-412-CRO
ICN-412-A-622000-B-97499-00079-A-001-01
Figure 7. Collective Drive Plate Set - Damage Repair Limits (Sheet 1 of 1)
412-A-62-20-00-02A-280B-B
Applicable to: ALL
Page 00068-14 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00078-A-001-01
Figure 8. Bracket - Damage Repair Limit (Sheet 1 of 1)
Applicable to: ALL
412-A-62-20-00-02A-280B-B
ECCN EAR99
14 NOV 2023 Page 00068-15
BHT-412-CRO
Intentionally blank page
412-A-62-20-00-02A-280B-B
Applicable to: ALL
Page 00068-16 14 NOV 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Hub and Sleeve Assembly (412-010-401-105, -107, -109, -111, -113, -115, and -117) Non-destructive Inspection
Procedure
1.
Do a Magnetic Particle Inspection (MPI) for the applicable parts shown in Table 1. Refer to BHT-ALL-SPM, Chapter
6, Standard Practices Manual for the MPI instructions.
2.
Do a Fluorescent Penetrant Inspection (FPI) for the applicable parts shown in Table 1. Refer to BHT-ALL-SPM,
Chapter 6, Standard Practices Manual for the FPI instructions.
3.
Discard all the parts, if the Non-Destructive Inspection (NDI) is unsatisfactory.
4.
Use a gauss meter to make sure magnetization of the parts is less than 3 gauss anywhere on the part. Otherwise,
demagnetize the part per the instructions contained in the BHT-ALL-SPM, Chapter 6, Standard Practices Manual.
Table 1. Main Rotor Hub and Sleeve Assembly- Non-Destructive Inspection
MAGNETIC PARTICLE
INSPECTION
FLUORESCENT
PENETRANT
INSPECTION
FIGURE NUMBER
NOMENCLATURE
PART NUMBER
Figure 1
Sleeve Nut
204-010-420
X
Figure 3
Collective Sleeve
204-011-408
X
Figure 3
Collective Sleeve
212-011-412
X
Figure 6
Rephasing Lever
412-010-403
X
Figure 4
Drive Link
412-010-405
X
Figure 5
Swashplate Link
Assembly
412-010-406
X
Figure 7
Collective Drive Plate
Set
412-010-429
X
Figure 2
Hub Assembly
412-010-445
X
Applicable to: ALL
412-A-62-20-00-02A-353A-B
ECCN EAR99
28 OCT 2024 Page 00069-1
BHT-412-CRO
ICN-412-A-622000-B-97499-00062-A-002-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 1 of 5)
412-A-62-20-00-02A-353A-B
Applicable to: ALL
Page 00069-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00063-A-001-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 2 of 5)
Applicable to: ALL
412-A-62-20-00-02A-353A-B
ECCN EAR99
28 OCT 2024 Page 00069-3
BHT-412-CRO
ICN-412-A-622000-B-97499-00064-A-001-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 3 of 5)
412-A-62-20-00-02A-353A-B
Applicable to: ALL
Page 00069-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00065-A-001-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 4 of 5)
Applicable to: ALL
412-A-62-20-00-02A-353A-B
ECCN EAR99
28 OCT 2024 Page 00069-5
BHT-412-CRO
ICN-412-A-622000-B-97499-00066-A-001-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 5 of 5)
412-A-62-20-00-02A-353A-B
Applicable to: ALL
Page 00069-6 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00071-A-001-01
Figure 2. Collective Sleeve Hub Assembly - Damage Repair Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-62-20-00-02A-353A-B
ECCN EAR99
28 OCT 2024 Page 00069-7
BHT-412-CRO
ICN-412-A-622000-B-97499-00072-A-001-01
Figure 3. Collective Sleeve - Damage Repair Limits (Sheet 1 of 2)
412-A-62-20-00-02A-353A-B
Applicable to: ALL
Page 00069-8 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00073-A-001-01
Figure 3. Collective Sleeve - Damage Repair Limits (Sheet 2 of 2)
Applicable to: ALL
412-A-62-20-00-02A-353A-B
ECCN EAR99
28 OCT 2024 Page 00069-9
BHT-412-CRO
ICN-412-A-622000-B-97499-00074-A-001-01
Figure 4. Drive Link Assembly - Damage Repair Limits (Sheet 1 of 1)
412-A-62-20-00-02A-353A-B
Applicable to: ALL
Page 00069-10 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00075-A-001-01
Figure 5. Swashplate Link Assembly - Damage Repair Limits (Sheet 1 of 2)
Applicable to: ALL
412-A-62-20-00-02A-353A-B
ECCN EAR99
28 OCT 2024 Page 00069-11
BHT-412-CRO
ICN-412-A-622000-B-97499-00076-A-001-01
Figure 5. Swashplate Link Assembly - Damage Repair Limits (Sheet 2 of 2)
412-A-62-20-00-02A-353A-B
Applicable to: ALL
Page 00069-12 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00077-A-001-01
Figure 6. Rephasing Lever Assembly - Damage Repair Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-62-20-00-02A-353A-B
ECCN EAR99
28 OCT 2024 Page 00069-13
BHT-412-CRO
ICN-412-A-622000-B-97499-00079-A-001-01
Figure 7. Collective Drive Plate Set - Damage Repair Limits (Sheet 1 of 1)
412-A-62-20-00-02A-353A-B
Applicable to: ALL
Page 00069-14 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Main Rotor Hub and Sleeve Assembly (412-010-401-105, -107, -109, -111, -113, -115, and -117) Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Chemical film material
Cadmium plating solution
Epoxy polyamide primer
Polyurethane thinner
Acetone
Abrasive cloth or paper
Crocus cloth
C-100
C-108
C-204
C-235
C-316
C-423
C-500
AR
AR
AR
AR
AR
AR
AR
Remarks
Procedure
1.
Replace the seals (47 and 53, Figure 1, Detail D).
2.
Replace the parts if the damage is more than the limits shown in Figure 2 through Figure 8.
3.
Replace the parts if the magnetic particle or penetrant inspection is unsatisfactory.
4.
Replace the parts which have non-repairable thread damage.
NOTE
It is recommended to replace the bearings (29, 30, 31, and 34) during the overhaul.
5.
Replace the unserviceable bearings (29, 30, 31 and 34, Figure 1, Detail B and Detail C). Bearing sets (44 and 46,
Detail D) must be replaced as a serialized set.
6.
Repair permitted corrosion and mechanical damage. Polish steel parts only to a depth sufficient to remove corrosion
and aluminum parts twice the depth of the deepest pit, not more than the limits of Figure 2 through Figure 8. Use fine
to medium grade abrasive cloth or paper (C-423) and final polish to a scratch-free surface with crocus cloth (C-500).
7.
Polish out score marks on the inside diameter of the bushings on the hub assembly (49, Figure 1, Detail D), drive
link (27, Detail B), and rephasing lever (9, Detail A) if subsequent repair does not exceed the limits shown in
Figure 2, Figure 4 and Figure 6.
8.
Replace unserviceable bushings (41A, 41B, 41C, 41D and 41E, Figure 1, Detail C) in the rephasing lever (9) as
follows:
NOTE
Refer to the BHT-ALL-SPM, Standard Practices Manual for bushing thermal fit procedures.
8.1.
Locally heat rephasing lever (9). Do not heat more than 200ºF (93ºC).
8.2.
Sufficiently support rephasing lever (9) and press out unserviceable bushing.
8.3.
Examine bore of rephasing lever (9) for damage. Refer to Figure 6.
8.4.
Locally heat rephasing lever (9). Do not heat more than 200ºF (93ºC).
8.5.
While supporting rephasing lever (9), install serviceable bushing with wet epoxy polyamide primer (C-204).
8.6.
Remove unwanted primer with acetone (C-316) or MIL-T-81772 TYII polyurethane thinner (C-235).
8.7.
Ream new bushings in-line with adjacent bushings or holes.
8.7.1.
Line ream bushings (41A) 0.6250 to 0.6260 inch (15.88 to 15.90 mm).
8.7.2.
Line ream bushings (41B, 41C and 41D) 0.3745 to 0.3755 inch (9.51 to 9.54 mm).
8.7.3.
Line ream bushings (41E) 0.4995 to 0.5005 inch (12.69 to 12.71 mm).
Applicable to: ALL
412-A-62-20-00-02A-685B-B
ECCN EAR99
14 NOV 2023 Page 00070-1
BHT-412-CRO
9.
Replace defective rod end bearings on the swashplate link assembly 412-010-406-111 or 412-010-406-113 or
412-010-406-115 or 412-010-406-117 (Figure 9).
10.
Replace the defective rod end bearings on the swashplate link assembly 412-010-406-113 (Figure 10).
11.
Apply cadmium plating solution (C-108) to the repaired areas on the steel parts where plating was removed. Refer
to Figure 11 for processing requirements and the BHT-ALL-SPM, Standard Practices Manual for cadmium plating
procedures.
12.
Apply chemical film material (C-100) to the repaired areas on aluminum parts. Refer to Figure 11 for processing
requirements. Refer to the BHT-ALL-SPM, Standard Practices Manual for procedure.
13.
Refinish the main rotor controls hub and sleeve components as shown in Figure 11. Refer to the
BHT-ALL-SPM, Standard Practices Manual for painting procedures.
412-A-62-20-00-02A-685B-B
Applicable to: ALL
Page 00070-2 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00062-A-002-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 1 of 5)
Applicable to: ALL
412-A-62-20-00-02A-685B-B
ECCN EAR99
14 NOV 2023 Page 00070-3
BHT-412-CRO
ICN-412-A-622000-B-97499-00063-A-001-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 2 of 5)
412-A-62-20-00-02A-685B-B
Applicable to: ALL
Page 00070-4 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00064-A-001-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 3 of 5)
Applicable to: ALL
412-A-62-20-00-02A-685B-B
ECCN EAR99
14 NOV 2023 Page 00070-5
BHT-412-CRO
ICN-412-A-622000-B-97499-00065-A-001-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 4 of 5)
412-A-62-20-00-02A-685B-B
Applicable to: ALL
Page 00070-6 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00066-A-001-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 5 of 5)
Applicable to: ALL
412-A-62-20-00-02A-685B-B
ECCN EAR99
14 NOV 2023 Page 00070-7
BHT-412-CRO
ICN-412-A-622000-B-97499-00071-A-001-01
Figure 2. Collective Sleeve Hub Assembly - Damage Repair Limits (Sheet 1 of 1)
412-A-62-20-00-02A-685B-B
Applicable to: ALL
Page 00070-8 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00072-A-001-01
Figure 3. Collective Sleeve - Damage Repair Limits (Sheet 1 of 2)
Applicable to: ALL
412-A-62-20-00-02A-685B-B
ECCN EAR99
14 NOV 2023 Page 00070-9
BHT-412-CRO
ICN-412-A-622000-B-97499-00073-A-001-01
Figure 3. Collective Sleeve - Damage Repair Limits (Sheet 2 of 2)
412-A-62-20-00-02A-685B-B
Applicable to: ALL
Page 00070-10 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00074-A-001-01
Figure 4. Drive Link Assembly - Damage Repair Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-62-20-00-02A-685B-B
ECCN EAR99
14 NOV 2023 Page 00070-11
BHT-412-CRO
ICN-412-A-622000-B-97499-00075-A-001-01
Figure 5. Swashplate Link Assembly - Damage Repair Limits (Sheet 1 of 2)
412-A-62-20-00-02A-685B-B
Applicable to: ALL
Page 00070-12 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00076-A-001-01
Figure 5. Swashplate Link Assembly - Damage Repair Limits (Sheet 2 of 2)
Applicable to: ALL
412-A-62-20-00-02A-685B-B
ECCN EAR99
14 NOV 2023 Page 00070-13
BHT-412-CRO
ICN-412-A-622000-B-97499-00077-A-001-01
Figure 6. Rephasing Lever Assembly - Damage Repair Limits (Sheet 1 of 1)
412-A-62-20-00-02A-685B-B
Applicable to: ALL
Page 00070-14 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00078-A-001-01
Figure 7. Bracket - Damage Repair Limit (Sheet 1 of 1)
Applicable to: ALL
412-A-62-20-00-02A-685B-B
ECCN EAR99
14 NOV 2023 Page 00070-15
BHT-412-CRO
ICN-412-A-622000-B-97499-00079-A-001-01
Figure 8. Collective Drive Plate Set - Damage Repair Limits (Sheet 1 of 1)
412-A-62-20-00-02A-685B-B
Applicable to: ALL
Page 00070-16 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00080-A-002-01
Figure 9. Swashplate Link Assembly (412-010-406-111, -115 and -117) (Sheet 1 of 2)
Applicable to: ALL
412-A-62-20-00-02A-685B-B
ECCN EAR99
14 NOV 2023 Page 00070-17
BHT-412-CRO
ICN-412-A-622000-B-97499-01028-A-001-01
Figure 9. Swashplate Link Assembly (412-010-406-111, -115 and -117) (Sheet 2 of 2)
412-A-62-20-00-02A-685B-B
Applicable to: ALL
Page 00070-18 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00081-A-001-01
Figure 10. Swashplate Link Assembly (412-010-406-113) (Sheet 1 of 2)
Applicable to: ALL
412-A-62-20-00-02A-685B-B
ECCN EAR99
14 NOV 2023 Page 00070-19
BHT-412-CRO
ICN-412-A-622000-B-97499-00082-A-001-01
Figure 10. Swashplate Link Assembly (412-010-406-113) (Sheet 2 of 2)
412-A-62-20-00-02A-685B-B
Applicable to: ALL
Page 00070-20 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00083-A-001-01
Figure 11. Main Rotor Hub and Sleeve Processing Requirements (Sheet 1 of 3)
Applicable to: ALL
412-A-62-20-00-02A-685B-B
ECCN EAR99
14 NOV 2023 Page 00070-21
BHT-412-CRO
ICN-412-A-622000-B-97499-00084-A-001-01
Figure 11. Main Rotor Hub and Sleeve Processing Requirements (Sheet 2 of 3)
412-A-62-20-00-02A-685B-B
Applicable to: ALL
Page 00070-22 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00085-A-001-01
Figure 11. Main Rotor Hub and Sleeve Processing Requirements (Sheet 3 of 3)
Applicable to: ALL
412-A-62-20-00-02A-685B-B
ECCN EAR99
14 NOV 2023 Page 00070-23
BHT-412-CRO
Intentionally blank page
412-A-62-20-00-02A-685B-B
Applicable to: ALL
Page 00070-24 14 NOV 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Hub and Sleeve Assembly (412-010-401-105, -107, -109, -111, -113, -115, and -117) Assembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Bearing Ram
Ram Adapter
Wrench
Bar
T101262-119
T101382
T101392
T101424
1
1
1
1
Remarks
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Grease
Corrosion preventive compound
Corrosion preventive compound
Drycleaning solvent
MEK
Adhesive
Lockwire
Abrasive cloth or paper
C-001
C-101
C-104
C-304
C-309
C-325
C-405
C-423
AR
AR
AR
AR
AR
AR
AR
AR
Remarks
Procedure
NOTE
If protective oil has been applied to the hub and sleeve components during storage, clean all parts fully
with drycleaning solvent (C-304) and dry with filtered compressed air before you assemble.
NOTE
Apply corrosion preventive compound (C-104) to all the bolts and mating surfaces before you assemble.
1.
Install the lower seal (47, Figure 1, Detail D) in the hub assembly (49) as follows:
1.1.
Lightly abrade the seal mating surface in the hub assembly (49) with 400 grit abrasive cloth or paper (C-423).
Remove the remaining sand with a soft cloth moistened with MEK (C-309).
1.2.
Apply a thin layer of adhesive (C-325) to the mating surfaces of the seal (47) and hub (49). Dry the adhesive for 10
minutes to get an aggressive tacky stage.
1.3.
Use a ram adapter (T101382) to push the seal (47) into the hub (49) with the lip of the seal pointing down. Remove
unwanted adhesive with a soft cloth moistened with MEK (C-309).
1.4.
Dry the adhesive for 4 hours.
1.5.
Slide the hub (49) down over the sleeve (48) past the bearing mating surface.
NOTE
Make sure the serial number identity on the bearing set. Bearings must be installed as a matched set.
2.
Install the bearings (44 and 46) with the spacer set (45) on the sleeve (48) as follows:
2.1.
Hand pack the bearings (44 and 46) with grease (C-001). Clean unwanted grease from the mating surfaces.
2.2.
Apply corrosion preventive compound (C-104) to the mating surfaces of the bearing sets (44 and 46) and sleeve (48).
2.3.
Push the bearing sets (44 and 46) with the spacer set (45) on the sleeve (48) (Figure 3).
Applicable to: ALL
412-A-62-20-00-02A-710A-B
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14 NOV 2023 Page 00071-1
BHT-412-CRO
3.
Use a wrench (T101392) and bar (T101424) (Figure 2) to install the nut (54, Figure 1, Detail D) on the sleeve (48).
Torque the nut (54) 150 to 200 foot-pounds (203 to 271 Nm). Install the pin (55, Figure 1, Detail D) in the nut (54)
and attach with lockwire (C-405).
4.
Move the hub (49) up the sleeve (48) on the bearing set. Tap lightly with a soft mallet to make sure that the
installation is correct.
5.
Install the shoulder ring (52) in the upper end of the hub (49).
6.
Apply a thin layer of adhesive (C-325) to the mating surface of the seal (53). Dry the adhesive for 10 minutes to get
an aggressive tacky stage. Install the seal (53) with the lip of the seal pointing up, between the shoulder ring (52)
and nut (54). Dry the adhesive for 4 hours.
NOTE
Make sure that the plate set (57) master spline is in correct position, as shown in Figure 1, Detail D, View
F.
7.
Temporarily install the plate set (57) and flange (58) on the hub (49) with the bolts (42), washers (43 and 50), and nuts
(51). Measure the clearance between the plate set and hub with the feeler gauge. Prepare the shim (56) to give
0.003 to 0.005 inch (0.08 to 0.13 mm) pinch on the bearing (44). Remove the temporarily installed parts.
8.
Install the measured shim (56), plate set (57), and flange (58) with the bolts (42), washers (43 and 50), and nuts (51).
Torque the nuts 50 to 70 inch-pounds (5.65 to 7.91 Nm).
9.
Hand pack the bearings (31 and 34, Detail C) with grease (C-001) and install with the spacer (32) in the hub (49)
using the bearing ram (T101262-119). Refer to Figure 4, View B and View C. Repeat the procedure for the remaining
hub bearing installations.
10.
Install the shaft (33, Figure 1, Detail C) through the bearings (31 and 34) and spacer (32).
11.
Center the shaft (33) in the hub and install the washers (35 and 41).
12.
Put the rephasing lever (9) on the hub boss with the short horn of the rephasing lever (9) toward the direction of
rotation (counterclockwise) and align with the shaft (33). Install the bolt (37) with the washers (36 and 38) and nut
(39). Torque the nut 24 to 34 foot-pounds (32 to 46 Nm) and install the new cotter pin (40). Repeat the procedure for
the remaining rephasing lever (9) installations.
13.
Install the bearings (26, 29 and 30, Detail B) in the drive link (27) per Figure 4, View E and View F.
14.
Insert the spacers (20 and 25, Figure 1, Detail B) through the upper drive link bearings (29 and 30). Center the spacers
and install the washers (18, 19 for -105 only, 24, and 28) over the end of the spacers. Align the drive link (27) in the
rephasing lever (9) and install the bolts (11 and 17) with the washers (12 and 16) and the washers (15 and 23) with the
nuts (14 and 22). Torque the nuts 165 to 200 inch-pounds (18.6 to 22.6 Nm). Install the new cotter pins (13 and 21).
NOTE
Main rotor hub and sleeve 412-010-401-105:
Make sure the swashplate link assembly 412-010-406-113 (with lower rod end bearing set at 90° to upper)
is installed directly across from the drive link (27).
Applicable: Main rotor hub and sleeve 412-010-401-105 and -107:
15.
Install the anti-torque bushing (5, Figure 1, Detail A) with the bolt (2) and washer (1) loosely installed. Put the
swashplate link (10) in the rephasing lever (9) short clevis with the serrated side of the rod end bearing facing the
bushing (5). Make sure that the serrations on the swashplate link (10) rod end bearing and bushing (5) are properly
engaged. Install the bolt (3) with the washer (4) and the nut (7) with the washer (6). Torque the nut 165 to 200
inch-pounds (18.6 to 22.6 Nm). Install the new cotter pin (8).
Applicable: Main rotor hub and sleeve 412-010-401-105 and -107:
16.
Torque the bolt (2) 30 to 40 inch-pounds (3.39 to 4.52 Nm) and secure with lockwire (C-405).
17.
Repeat Step 15. and Step 16. to install the remaining swashplate link assemblies.
Applicable: Main rotor hub and sleeve 412-010-401-109, -111, -113, -115, and -117:
18.
Put the swashplate link assembly (10) in the rephasing lever (9) short clevis. Put the bracket (5B) with the bushing
(5A and 5C) on the rephasing lever. Make sure that the stud on the rod end seats in the bracket (10) hole and install
412-A-62-20-00-02A-710A-B
Applicable to: ALL
Page 00071-2 14 NOV 2023
ECCN EAR99
BHT-412-CRO
the bolt (3), washers (4 and 6), and nut (7). Torque the nut 165 to 200 inch-pounds (18.6 to 22.6 Nm). Install the new
cotter pin (8). Use the same procedure to install the remaining swashplate link assembly.
19.
Purge lubricate all the grease fittings (10 places) after you assemble with grease (C-001) until the grease vents
past the seals. Clean unwanted grease.
20.
Apply a layer of corrosion preventive compound (C-101) to all the bolt heads, washers, nut, and exposed joints.
Applicable to: ALL
412-A-62-20-00-02A-710A-B
ECCN EAR99
14 NOV 2023 Page 00071-3
BHT-412-CRO
ICN-412-A-622000-B-97499-00062-A-002-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 1 of 5)
412-A-62-20-00-02A-710A-B
Applicable to: ALL
Page 00071-4 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00063-A-001-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 2 of 5)
Applicable to: ALL
412-A-62-20-00-02A-710A-B
ECCN EAR99
14 NOV 2023 Page 00071-5
BHT-412-CRO
ICN-412-A-622000-B-97499-00064-A-001-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 3 of 5)
412-A-62-20-00-02A-710A-B
Applicable to: ALL
Page 00071-6 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00065-A-001-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 4 of 5)
Applicable to: ALL
412-A-62-20-00-02A-710A-B
ECCN EAR99
14 NOV 2023 Page 00071-7
BHT-412-CRO
ICN-412-A-622000-B-97499-00066-A-001-01
Figure 1. Main Rotor Hub and Sleeve Assembly (Sheet 5 of 5)
412-A-62-20-00-02A-710A-B
Applicable to: ALL
Page 00071-8 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00069-A-001-01
Figure 2. Tool Application - Wrench (T101392) and Bar (T101424) (Sheet 1 of 1)
Applicable to: ALL
412-A-62-20-00-02A-710A-B
ECCN EAR99
14 NOV 2023 Page 00071-9
BHT-412-CRO
ICN-412-A-622000-B-97499-00070-A-001-01
Figure 3. Tool Application - Support (T101369) and Ram Adapter (T101382) (Sheet 1 of 1)
412-A-62-20-00-02A-710A-B
Applicable to: ALL
Page 00071-10 14 NOV 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-622000-B-97499-00067-A-001-01
Figure 4. Bearing Ram (T101262-119) - Tool Application (Sheet 1 of 2)
Applicable to: ALL
412-A-62-20-00-02A-710A-B
ECCN EAR99
14 NOV 2023 Page 00071-11
BHT-412-CRO
ICN-412-A-622000-B-97499-00068-A-001-01
Figure 4. Bearing Ram (T101262-119) - Tool Application (Sheet 2 of 2)
412-A-62-20-00-02A-710A-B
Applicable to: ALL
Page 00071-12 14 NOV 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Controls Pitch Link - Disassembly
Procedure
NOTE
Do not attempt to remove the inserts (3 and 6, Figure 1) from the tube assembly (9). If replacement of
the insert is required, return the tube to Bell Helicopter Textron (BHT).
1.
Loosen the nut (2) and remove the rod end bearing (1) from the tube (9). Remove the nut from the bearing.
2.
Loosen the nut (7) and remove the rod end bearing (8) from the tube assembly (9). Remove the nut from the rod
end bearing.
Applicable to: ALL
412-A-62-30-00-00A-530A-B
ECCN EAR99
31 MAY 2023 Page 00072-1
BHT-412-CRO
ICN-412-A-623000-B-97499-00001-A-001-01
Figure 1. Main Rotor Controls Pitch Link (Sheet 1 of 1)
412-A-62-30-00-00A-530A-B
Applicable to: ALL
Page 00072-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Controls Pitch Link - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Corrosion preventive oil
Drycleaning solvent
Barrier material
Barrier tape
C-126
C-304
C-427
C-456
AR
AR
AR
AR
Remarks
Procedure
DO NOT IMMERSE ROD END BEARINGS (1 AND 8, Figure 1) IN DRYCLEANING SOLVENT.
1.
Wipe the rod end bearings clean with a cloth moistened with drycleaning solvent (C-304). The pitch link tube
assembly (9) may be cleaned by wiping or spraying.
2.
Dry parts with filtered compressed air.
3.
Remove finish from the tube assembly (9). Refer to the BHT-ALL-SPM, Standard Practices Manual for paint remover
types and usage.
4.
When the tube is not to be processed immediately after cleaning, apply corrosion preventive oil (C-126). Wrap the
tube in barrier material (C-427) and secure with barrier tape (C-456).
Applicable to: ALL
412-A-62-30-00-00A-258A-B
ECCN EAR99
31 MAY 2023 Page 00073-1
BHT-412-CRO
ICN-412-A-623000-B-97499-00001-A-001-01
Figure 1. Main Rotor Controls Pitch Link (Sheet 1 of 1)
412-A-62-30-00-00A-258A-B
Applicable to: ALL
Page 00073-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Controls Pitch Link - Inspection
Procedure
1.
Examine the main rotor controls pitch links in accordance with Figure 2 and 412-A-62-30-00-00A-353A-B / 00075.
2.
Do a check of the bond for each insert (3 and 6, Figure 1) of the tube assembly (9) as follows:
EXERCISE CAUTION WHEN SUPPORTING THE PITCH LINK TUBE TO ENSURE THAT YOU DO NOT
SCRATCH OR DISTORT THE TUBE. FAILURE TO DO SO MAY DAMAGE THE PART.
2.1.
Support the pitch link assembly (10) in the V-blocks placed near each end of the tube assembly (9).
2.2.
Apply 400 inch-pounds (45.2 Nm) of torque simultaneously to both inserts (3 and 6) in a loosening direction.
2.3.
If the insert (3 or 6) is loose, replace the tube assembly (9).
2.4.
Check rotational eccentricity at any point on the tube assembly (9) with a dial indicator. Total indicator reading shall
not exceed 0.020 inch (0.51 mm).
3.
Do a check of the tube assembly (9) for water tightness as follows:
3.1.
Using a suitable container filled with 135 to 155°F (57 to 68°C) water, fully immerse the tube assembly (9) for 2
minutes.
3.2.
Any air bubbles detected from the tube assembly (9) as a result of the water immersion is cause for rejection of
the tube assembly.
3.3.
Provided no air bubbles are detected, the tube assembly (9) may be considered serviceable.
Applicable to: ALL
412-A-62-30-00-00A-280A-B
ECCN EAR99
31 MAY 2023 Page 00074-1
BHT-412-CRO
ICN-412-A-623000-B-97499-00001-A-001-01
Figure 1. Main Rotor Controls Pitch Link (Sheet 1 of 1)
412-A-62-30-00-00A-280A-B
Applicable to: ALL
Page 00074-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-00003-A-001-01
Figure 2. Main Rotor Controls Pitch Link - Damage Repair Limits (Sheet 1 of 2)
Applicable to: ALL
412-A-62-30-00-00A-280A-B
ECCN EAR99
31 MAY 2023 Page 00074-3
BHT-412-CRO
ICN-412-A-623000-B-97499-00004-A-001-01
Figure 2. Main Rotor Controls Pitch Link - Damage Repair Limits (Sheet 2 of 2)
412-A-62-30-00-00A-280A-B
Applicable to: ALL
Page 00074-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Controls Pitch Link - Non-destructive Inspection
Procedure
1.
Do a Fluorescent Penetrant Inspection (FPI) for the applicable parts shown in Table 1 in accordance with the
instructions provided in the BHT-ALL-SPM, Chapter 6, Standard Practices Manual.
2.
Discard all the parts that fail the Non-Destructive Inspection (NDI) criteria.
Table 1. Main Rotor Controls Pitch Link - Non-Destructive Inspection
FIGURE NUMBER
NOMENCLATURE
PART NUMBER
Figure 1
Pitch Link
412-010-425
FLUORESCENT PENETRANT
INSPECTION
X
Applicable to: ALL
412-A-62-30-00-00A-353A-B
ECCN EAR99
31 MAY 2023 Page 00075-1
BHT-412-CRO
ICN-412-A-623000-B-97499-00003-A-001-01
Figure 1. Main Rotor Controls Pitch Link - Damage Repair Limits (Sheet 1 of 2)
412-A-62-30-00-00A-353A-B
Applicable to: ALL
Page 00075-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-00004-A-001-01
Figure 1. Main Rotor Controls Pitch Link - Damage Repair Limits (Sheet 2 of 2)
Applicable to: ALL
412-A-62-30-00-00A-353A-B
ECCN EAR99
31 MAY 2023 Page 00075-3
BHT-412-CRO
Intentionally blank page
412-A-62-30-00-00A-353A-B
Applicable to: ALL
Page 00075-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Controls Pitch Link - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Chemical film material
Epoxy polyamide primer
Polyurethane coating
Adhesive
Abrasive cloth or paper
C-100
C-204
C-245
C-313
C-423
AR
AR
AR
AR
AR
Remarks
Procedure
1.
Replace defective rod end bearings (1 and 8, Figure 2) if damaged or worn beyond limits (Figure 1 and
412-A-62-30-00-00A-258A-B / 00073).
2.
Replace missing or illegible name plates (4, Figure 2) or decal (5). Use adhesive (C-313) (BHT-ALL-SPM, Standard
Practices Manual).
3.
Polish out mechanical and corrosion damage that is within limits shown in Figure 1. Use fine to medium grade
abrasive cloth or paper (C-423).
4.
Touch up areas where chemical film has been removed from the tube assembly (9, Figure 2). Use chemical film
material (C-100) for aluminum alloy. Refer to the BHT-ALL-SPM, Standard Practices Manual for the procedure to
apply chemical film.
5.
Refinish the tube assembly (9), except the threaded inserts, nameplate, and decal as follows:
5.1.
Apply one coat of epoxy polyamide primer (C-204) (BHT-ALL-SPM, Standard Practices Manual).
5.2.
Apply a mist coat of epoxy polyamide primer (C-204) and two coats of polyurethane coating (C-245), color light
gull gray (BHT-ALL-SPM, Standard Practices Manual).
Applicable to: ALL
412-A-62-30-00-00A-685A-B
ECCN EAR99
31 MAY 2023 Page 00076-1
BHT-412-CRO
ICN-412-A-623000-B-97499-00003-A-001-01
Figure 1. Main Rotor Controls Pitch Link - Damage Repair Limits (Sheet 1 of 2)
412-A-62-30-00-00A-685A-B
Applicable to: ALL
Page 00076-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-00004-A-001-01
Figure 1. Main Rotor Controls Pitch Link - Damage Repair Limits (Sheet 2 of 2)
Applicable to: ALL
412-A-62-30-00-00A-685A-B
ECCN EAR99
31 MAY 2023 Page 00076-3
BHT-412-CRO
ICN-412-A-623000-B-97499-00001-A-001-01
Figure 2. Main Rotor Controls Pitch Link (Sheet 1 of 1)
412-A-62-30-00-00A-685A-B
Applicable to: ALL
Page 00076-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Controls Pitch Link - Assembly
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Corrosion preventive compound
C-104
AR
Remarks
Procedure
1.
Coat the threads of the rod end bearings (1 and 8, Figure 1) and inserts (3 and 6) with corrosion preventive
compound (C-104).
2.
Install the nuts (2 and 7) on the rod end bearings (1 and 8).
3.
Install the rod end bearings in the tube assembly (9).
4.
Adjust the pitch link assembly to the dimensions shown in Figure 2.
5.
Tighten the nuts (2 and 7, Figure 1) sufficiently to prevent rod end movement. Torque and lockwire will be
accomplished at installation.
Applicable to: ALL
412-A-62-30-00-00A-710A-B
ECCN EAR99
31 MAY 2023 Page 00077-1
BHT-412-CRO
ICN-412-A-623000-B-97499-00001-A-001-01
Figure 1. Main Rotor Controls Pitch Link (Sheet 1 of 1)
412-A-62-30-00-00A-710A-B
Applicable to: ALL
Page 00077-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-00002-A-001-01
Figure 2. Main Rotor Controls Pitch Link Initial Dimensions (Sheet 1 of 1)
Applicable to: ALL
412-A-62-30-00-00A-710A-B
ECCN EAR99
31 MAY 2023 Page 00077-3
BHT-412-CRO
Intentionally blank page
412-A-62-30-00-00A-710A-B
Applicable to: ALL
Page 00077-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Controls Swashplate and Support - Disassembly
Procedure
REFER TO CONDITIONAL INSPECTION, 412-A-62-30-00-05A-284A-B / 00081, PRIOR TO
DISASSEMBLY.
BOLTS (25 AND 32, Figure 1) MIGHT BE DIFFICULT TO REMOVE DUE TO RETAINING COMPOUND
AND MUST BE PRESSED OUT. SUPPORT THE LUGS OF INNER RING (26) AND SUPPORT (37) TO
PREVENT DAMAGE DURING BOLT REMOVAL.
HEAT MAY BE APPLIED TO SOFTEN THE RETAINING COMPOUND BUT DOES NOT EXCEED 150°F
(66°C).
NOTE
Refer to the mandatory Airworthiness Limitations Schedule in the BHT-412-MM for airworthiness life
on rotating controls components. Identify the components that have accumulated hours for retirement.
If the swashplate and support are being disassembled for replacement of parts instead of overhaul,
disassemble only to the extent necessary to replace parts.
1.
Remove the bolts (25, Figure 1) and separate the inner ring assembly (26) from the gimbal ring assembly (27).
Secure the bushings (48) to the inner ring, when working with the inner ring 204-011-402-125.
2.
Remove the bolts (32) and separate the gimbal ring assembly (27) from the support assembly (37).
3.
For gimbal ring (27) P/N 204-010-404-001, do as follows:
3.1.
Cut and remove the lockwire.
3.2.
Remove the screws (31) and separate the shim (28) and liner (29) with the bearing (30) from the gimbal ring
assembly (27). Press the bearing from the liner and discard the bearing. Repeat the procedure for the three
remaining bearing and liner assemblies.
4.
For gimbal ring (51) 212-010-416-101, do as follows:
4.1.
Cut and remove the lockwire.
4.2.
Remove the bolts (50) and separate the shim (52) and liner (58) with the bearing (59) from the gimbal ring assembly
(51). Press the bearing from the liner and discard the bearing. Repeat the procedure for the three remaining bearing
and liner assemblies.
5.
Remove nuts (1) and the washers (2), and lift off the cover (3).
6.
For the swashplate and support assemblies using the outer cap 540-011-434-111, shim 412-010-404-101, and outer
ring 412-010-407-117 combination, or helicopters Post ASB-412-08-131, disassemble as follows:
6.1.
Remove the two nuts (7) and the washers (8) from the outer cap (11).
6.2.
Remove the nuts (19), 14 bolts (9), and steel washers (10 and 18).
6.3.
Remove the outer cap (11), inner cap (5), and two sets of shims (6 and 12).
6.4.
Remove the seal (4) from the outer cap (11).
THE SERIAL NUMBER OF THE BEARING COMPONENTS MUST BE THE SAME. BEARING
COMPONENTS ARE A MATCHED SET. INSTALLATION OF A COMPONENT FROM ANOTHER SET
WILL RESULT IN INCORRECT OPERATION.
Applicable to: ALL
412-A-62-30-00-05A-530A-B
ECCN EAR99
31 MAY 2023 Page 00078-1
BHT-412-CRO
7.
Remove the bearing set (13) and seal (20) from the outer ring.
EXCESSIVE SPREADING OF THE TRUNNION CLAMP AREA OF THE INNER RING COULD CAUSE
A CRACK RESULTING IN LOSS OF ROTOR CONTROL. AFTER REMOVING BOLTS AND PLATES,
INSERT TANGS OF WORKAID INTO SLOT AND TIGHTEN SCREW UNTIL TRUNNION (44) CAN
BARELY BE PULLED OUT. IMMEDIATELY RELEASE SCREW TENSION AND REMOVE WORKAID.
8.
Remove three nuts (38), aluminum washers (39 and 40), and bolts (41) and remove plates (42 and 45) from inner
ring assembly (26). Secure spacer (43) to inner ring.
9.
Remove two trunnions (44, Figure 1) using workaid (Figure 2).
412-A-62-30-00-05A-530A-B
Applicable to: ALL
Page 00078-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-00005-A-001-01
Figure 1. Main Rotor Controls Swashplate and Support Assembly (Sheet 1 of 3)
Applicable to: ALL
412-A-62-30-00-05A-530A-B
ECCN EAR99
31 MAY 2023 Page 00078-3
BHT-412-CRO
ICN-412-A-623000-B-97499-00006-A-001-01
Figure 1. Main Rotor Controls Swashplate and Support Assembly (Sheet 2 of 3)
412-A-62-30-00-05A-530A-B
Applicable to: ALL
Page 00078-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-00007-A-001-01
Figure 1. Main Rotor Controls Swashplate and Support Assembly (Sheet 3 of 3)
Applicable to: ALL
412-A-62-30-00-05A-530A-B
ECCN EAR99
31 MAY 2023 Page 00078-5
BHT-412-CRO
ICN-412-A-623000-B-97499-00008-A-001-01
Figure 2. Workaid - Trunnion Removal and Installation (Sheet 1 of 1)
412-A-62-30-00-05A-530A-B
Applicable to: ALL
Page 00078-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Controls Swashplate and Support - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Corrosion preventive compound
Corrosion preventive oil
Drycleaning solvent
Barrier material
Barrier tape
Paint remover
C-105
C-126
C-304
C-427
C-456
C-435
AR
AR
AR
AR
AR
AR
Remarks
Procedure
NOTE
Do not immerse shielded or sealed bearings in drycleaning solvent. Wipe clean with a drycleaning solvent
dampened cloth.
1.
Clean parts with drycleaning solvent (C-304). Dry with filtered, compressed air.
2.
Remove fingerprints or similar contamination from bearing surfaces, steel liners, and sleeves with corrosion
preventive compound (C-105) and do a final rinse with drycleaning solvent (C-304).
3.
Clean bearing liners on inner and outer rings by blasting with glass beads after inspection.
NOTE
Parts requiring magnetic particle inspection shall be stripped of acrylic lacquer finish. Parts requiring
fluorescent penetrant inspection shall be stripped of all finishes.
4.
Remove the finish from parts with paint remover (C-435) where required to facilitate inspection and repair
(BHT-ALL-SPM, Standard Practices Manual).
5.
When parts are not to be processed immediately after cleaning, apply corrosion preventive oil (C-126) to all parts.
Wrap parts in barrier material (C-427) and secure with barrier tape (C-456).
Applicable to: ALL
412-A-62-30-00-05A-258A-B
ECCN EAR99
31 MAY 2023 Page 00079-1
BHT-412-CRO
Intentionally blank page
412-A-62-30-00-05A-258A-B
Applicable to: ALL
Page 00079-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Controls Swashplate and Support - Inspection
Procedure
1.
NOTE
If records of physical appearance of the swashplate and support indicate that the assembly has
been subjected to an accident or incident outside the realm of normal usage, perform the conditional
inspection, 412-A-62-30-00-05A-284A-B / 00081. If the swash plate and support does not require a
conditional inspection, accomplish the normal inspection, 412-A-62-30-00-05A-280B-B / 00082. Refer
to the BHT-412-MM, Chapter 5 for definition of accidents that require a conditional inspection to be
conducted.
Applicable to: ALL
412-A-62-30-00-05A-280A-B
ECCN EAR99
31 MAY 2023 Page 00080-1
BHT-412-CRO
Intentionally blank page
412-A-62-30-00-05A-280A-B
Applicable to: ALL
Page 00080-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Controls Swashplate and Support - Conditional Inspection
Procedure
1.
Visually inspect the assembled component for any apparent damage or abnormal appearance. Obvious defects,
which are cause to scrap the entire assembly, are as follows:
1.1.
Binding in any of the pivot joints.
1.2.
Binding of outer ring on inner ring.
2.
Any detail part that has sustained surface damage shall be subject to surface damage inspection as outlined in
412-A-62-30-00-05A-280B-B / 00082. Surface damage that exceeds limits will require scrapping only the damaged
parts.
Applicable: ASB-412-93-71: Post:
3.
Inspect the swashplate support assembly (37, Figure 1), as follows:
3.1.
With the aid of a straight edge, check flat areas of the gimbal support lugs for deformation. Deviations from flat in
excess of 0.002 inch per 1.0 inch (0.05 mm per 25 mm) are cause to scrap the support.
3.2.
The base surface of the support shall be flat, within 0.001 inch per 1.0 inch (0.03 mm per 25 mm).
3.3.
The bolt 20-057-8-920 and bushing 412-010-020 must fit freely in the collective lever support (37). Any binding is
cause for scrapping the support.
4.
Inspect the inner ring assembly (26) as follows:
Applicable: TB 412-92-113: Pre:
4.1.
The bolt (25, Detail B, Figure 1) and bushing (48) must fit freely in the inner ring assembly and bushing. Any binding
is cause for scrapping the inner ring assembly.
4.2.
With the aid of a straight edge, check flat areas of the gimbal support lugs for deformation. Deviations from flat in
excess of 0.002 inch per 1.0 inch (0.05 mm per 25 mm) are cause to scrap the inner ring assembly .
4.3.
The top surface must be flat within 0.002 inch per 1.0 inch (0.05 mm per 25 mm).
5.
Inspect the outer ring assembly (15) as follows:
5.1.
The bearing liner ID shall be round within 0.002 inch (0.05 mm).
5.2.
Check several segments around the top for flatness with the straight edge. Not more than two holes should be
outboard of the straight edge when performing a check. The ring shall be flat within 0.001 inch per 1.0 inch (0.03
mm per 25 mm) over the length measured.
6.
Do the normal inspection, 412-A-62-30-00-05A-280B-B / 00082.
Applicable to: ALL
412-A-62-30-00-05A-284A-B
ECCN EAR99
31 MAY 2023 Page 00081-1
BHT-412-CRO
ICN-412-A-623000-B-97499-00005-A-001-01
Figure 1. Main Rotor Controls Swashplate and Support Assembly (Sheet 1 of 3)
412-A-62-30-00-05A-284A-B
Applicable to: ALL
Page 00081-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-00006-A-001-01
Figure 1. Main Rotor Controls Swashplate and Support Assembly (Sheet 2 of 3)
Applicable to: ALL
412-A-62-30-00-05A-284A-B
ECCN EAR99
31 MAY 2023 Page 00081-3
BHT-412-CRO
ICN-412-A-623000-B-97499-00007-A-001-01
Figure 1. Main Rotor Controls Swashplate and Support Assembly (Sheet 3 of 3)
412-A-62-30-00-05A-284A-B
Applicable to: ALL
Page 00081-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Controls Swashplate and Support - Normal Inspection
Procedure
RAPID OR CONTINUED ROTATION WILL SCORE RACES OF UNLUBRICATED BEARING.
1.
Inspect the bearing (13, Figure 1) for dents, deformation, cracks, corrosion, signs of overheating, and looseness
due to wear. Check by feel for indications of internal damage. (Brinelling, spalling, and cracked or broken balls)
by placing cleaned thrust bearing flat on a clean surface and applying even pressure with palms and heels of
hands while turning bearing slowly.
2.
Inspect the trunnions (44, Figure 1) as follows:
NOTE
The trunnion bearings are different from other bearings, which normally can be feel-checked for roughness
and ease of rotation. The trunnion bearings are preloaded into the cylinder portion of the trunnion with a
0.0005 inch (0.013 mm) tight to 0.005 inch (0.13 mm) loose tolerance. The feeling of roughness is due
to the preloaded and angular faces of the inner and outer races.
2.1.
Rotate the trunnion bearing and apply slight outboard pressure to determine the trunnion bearing position where
maximum axial looseness can be felt.
2.2.
Measure axial play with the dial indicator. Maximum acceptable axial play is 0.020 inch (0.51 mm).
3.
Inspect the cover (3, Figure 1), inner cap (5), and outer cap (11) for damage or deformation. Pay particular attention
to seal mating surfaces on the inner cap (5) and outer cap (11).
4.
Inspect the plates (42 and 45) and spacer (43) for damage or deformation.
5.
Inspect the swashplate support (37, Figure 1) in accordance with Figure 2 and 412-A-62-30-00-05A-353A-B / 00083.
6.
Inspect the gimbal ring (27, Figure 1) in accordance with Figure 3 and 412-A-62-30-00-05A-353A-B / 00083.
7.
Inspect the inner ring (26, Figure 1) in accordance with Figure 4 and 412-A-62-30-00-05A-353A-B / 00083.
8.
Inspect the outer ring (15, Figure 1) in accordance with Figure 5 and 412-A-62-30-00-05A-353A-B / 00083.
9.
Inspect liner (29, Figure 1) and bearing (30) in accordance with Figure 6.
Applicable to: ALL
412-A-62-30-00-05A-280B-B
ECCN EAR99
31 MAY 2023 Page 00082-1
BHT-412-CRO
ICN-412-A-623000-B-97499-00005-A-001-01
Figure 1. Main Rotor Controls Swashplate and Support Assembly (Sheet 1 of 3)
412-A-62-30-00-05A-280B-B
Applicable to: ALL
Page 00082-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-00006-A-001-01
Figure 1. Main Rotor Controls Swashplate and Support Assembly (Sheet 2 of 3)
Applicable to: ALL
412-A-62-30-00-05A-280B-B
ECCN EAR99
31 MAY 2023 Page 00082-3
BHT-412-CRO
ICN-412-A-623000-B-97499-00007-A-001-01
Figure 1. Main Rotor Controls Swashplate and Support Assembly (Sheet 3 of 3)
412-A-62-30-00-05A-280B-B
Applicable to: ALL
Page 00082-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-00010-A-001-01
Figure 2. Main Rotor Control Swashplate Support - Damage Repair Limits (Sheet 1 of 2)
Applicable to: ALL
412-A-62-30-00-05A-280B-B
ECCN EAR99
31 MAY 2023 Page 00082-5
BHT-412-CRO
ICN-412-A-623000-B-97499-00011-A-001-01
Figure 2. Main Rotor Control Swashplate Support - Damage Repair Limits (Sheet 2 of 2)
412-A-62-30-00-05A-280B-B
Applicable to: ALL
Page 00082-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-00012-A-001-01
Figure 3. Main Rotor Control Gimbal Ring - Damage Repair Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-62-30-00-05A-280B-B
ECCN EAR99
31 MAY 2023 Page 00082-7
BHT-412-CRO
ICN-412-A-623000-B-97499-00013-A-001-01
Figure 4. Main Rotor Controls Swashplate Inner Ring - Damage Repair Limits (Sheet 1 of 2)
412-A-62-30-00-05A-280B-B
Applicable to: ALL
Page 00082-8 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-00014-A-001-01
Figure 4. Main Rotor Controls Swashplate Inner Ring - Damage Repair Limits (Sheet 2 of 2)
Applicable to: ALL
412-A-62-30-00-05A-280B-B
ECCN EAR99
31 MAY 2023 Page 00082-9
BHT-412-CRO
ICN-412-A-623000-B-97499-00015-A-001-01
Figure 5. Main Rotor Controls Swashplate Outer Ring - Damage Repair Limits (Sheet 1 of 1)
412-A-62-30-00-05A-280B-B
Applicable to: ALL
Page 00082-10 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-00016-A-001-01
Figure 6. Main Rotor Controls Bearing and Liner - Damage Repair Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-62-30-00-05A-280B-B
ECCN EAR99
31 MAY 2023 Page 00082-11
BHT-412-CRO
Intentionally blank page
412-A-62-30-00-05A-280B-B
Applicable to: ALL
Page 00082-12 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Controls Swashplate and Support - Non-destructive Inspection
Procedure
1.
Do a Magnetic Particle Inspection (MPI) for the applicable parts shown in Table 1 in accordance with the instructions
provided in the BHT-ALL-SPM, Chapter 6, Standard Practices Manual.
2.
Do a Fluorescent Penetrant Inspection (FPI) for the applicable parts shown in Table 1 in accordance with the
instructions provided in the BHT-ALL-SPM, Chapter 6, Standard Practices Manual.
3.
Discard all the parts that fail the Non-Destructive Inspection (NDI) criteria.
4.
Use a gauss meter to make sure magnetization of the parts is less than 3 gauss anywhere on the part. Otherwise,
demagnetize the part per the instructions contained in the BHT-ALL-SPM, Chapter 6, Standard Practices Manual.
Table 1. Main Rotor Controls Swashplate and Support - Non-Destructive Inspection
MAGNETIC PARTICLE
INSPECTION
FLUORESCENT
PENETRANT
INSPECTION
FIGURE NUMBER
NOMENCLATURE
PART NUMBER
Figure 2
Gimbal Ring
204-010-404
Figure 3
Inner Ring
204-011-402
X
Figure 4
Outer Ring
412-010-407
X
Figure 1
Swashplate Support
Assembly
412-010-443
X
Figure 1
Swashplate Support
Assembly
412-010-453
X
X
Applicable to: ALL
412-A-62-30-00-05A-353A-B
ECCN EAR99
31 MAY 2023 Page 00083-1
BHT-412-CRO
ICN-412-A-623000-B-97499-00010-A-001-01
Figure 1. Main Rotor Control Swashplate Support - Damage Repair Limits (Sheet 1 of 2)
412-A-62-30-00-05A-353A-B
Applicable to: ALL
Page 00083-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-00011-A-001-01
Figure 1. Main Rotor Control Swashplate Support - Damage Repair Limits (Sheet 2 of 2)
Applicable to: ALL
412-A-62-30-00-05A-353A-B
ECCN EAR99
31 MAY 2023 Page 00083-3
BHT-412-CRO
ICN-412-A-623000-B-97499-00012-A-001-01
Figure 2. Main Rotor Control Gimbal Ring - Damage Repair Limits (Sheet 1 of 1)
412-A-62-30-00-05A-353A-B
Applicable to: ALL
Page 00083-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-00013-A-001-01
Figure 3. Main Rotor Controls Swashplate Inner Ring - Damage Repair Limits (Sheet 1 of 2)
Applicable to: ALL
412-A-62-30-00-05A-353A-B
ECCN EAR99
31 MAY 2023 Page 00083-5
BHT-412-CRO
ICN-412-A-623000-B-97499-00014-A-001-01
Figure 3. Main Rotor Controls Swashplate Inner Ring - Damage Repair Limits (Sheet 2 of 2)
412-A-62-30-00-05A-353A-B
Applicable to: ALL
Page 00083-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-00015-A-001-01
Figure 4. Main Rotor Controls Swashplate Outer Ring - Damage Repair Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-62-30-00-05A-353A-B
ECCN EAR99
31 MAY 2023 Page 00083-7
BHT-412-CRO
Intentionally blank page
412-A-62-30-00-05A-353A-B
Applicable to: ALL
Page 00083-8 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Controls Swashplate and Support - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Chemical film material
Cadmium plating solution
Epoxy polyamide primer
Polyurethane coating
Abrasive cloth or paper
C-100
C-108
C-204
C-245
C-423
AR
AR
AR
AR
AR
Remarks
Procedure
1.
Polish out corrosion and mechanical damage. Polish steel parts only to a depth sufficient to remove corrosion and
aluminum parts twice the depth of the deepest pit. If damage exceeds the limits of Figure 1 through Figure 5, Figure 8
and Figure 9 the affected part is not airworthy or repairable. Use abrasive cloth or paper (C-423) to polish out damage.
NOTE
The replacement of fixed bushings in the inner ring assembly 204-011-402-125 or -131, support assembly
412-010-443-109, and 412-010-453-105, and outer ring assembly 412-010-407-117 (26, 37, and 15,
Figure 7) is not authorized. Return these parts to Bell Helicopters Textron for bushing replacement.
2.
Polish out score marks on the inside diameter of the bushings on the inner ring assembly (26), support assembly (37),
and outer ring (15) if subsequent repair does not exceed the limits shown in Figure 1, Figure 3, and Figure 4.
3.
Replace loose or defective studs on the inner ring assembly (26, Figure 7). Refer to the BHT-ALL-SPM, Standard
Practices Manual for the procedure.
4.
Apply cadmium plating solution (C-108) to repaired areas on the steel parts where plating was removed. Refer to the
BHT-ALL-SPM, Standard Practices Manual for the procedure.
5.
Touch up areas on the swashplate support assembly (37) and the swashplate outer and inner ring assemblies
(15 and 26) where chemical film material has been removed. Refer to the notes in Figure 6. Refer to the
BHT-ALL-SPM, Standard Practices Manual for instructions to apply chemical film material (C-100) to the aluminum
alloy parts.
6.
Prime and paint the swashplate support assembly (37, Figure 7) and the swashplate outer ring assembly (15) with
one coat of epoxy polyamide primer (C-204) and two coats of polyurethane coating (C-245) (color code 36440 per
FED-STD-595). Refer to the notes in Figure 6.
7.
Paint the swashplate inner ring assembly (26) with two coats of polyurethane coating (C-245) (clear lacquer).
Refer to the notes in Figure 6.
Applicable to: ALL
412-A-62-30-00-05A-685A-B
ECCN EAR99
31 MAY 2023 Page 00084-1
BHT-412-CRO
ICN-412-A-623000-B-97499-00010-A-001-01
Figure 1. Main Rotor Control Swashplate Support - Damage Repair Limits (Sheet 1 of 2)
412-A-62-30-00-05A-685A-B
Applicable to: ALL
Page 00084-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-00011-A-001-01
Figure 1. Main Rotor Control Swashplate Support - Damage Repair Limits (Sheet 2 of 2)
Applicable to: ALL
412-A-62-30-00-05A-685A-B
ECCN EAR99
31 MAY 2023 Page 00084-3
BHT-412-CRO
ICN-412-A-623000-B-97499-00012-A-001-01
Figure 2. Main Rotor Control Gimbal Ring - Damage Repair Limits (Sheet 1 of 1)
412-A-62-30-00-05A-685A-B
Applicable to: ALL
Page 00084-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-00013-A-001-01
Figure 3. Main Rotor Controls Swashplate Inner Ring - Damage Repair Limits (Sheet 1 of 2)
Applicable to: ALL
412-A-62-30-00-05A-685A-B
ECCN EAR99
31 MAY 2023 Page 00084-5
BHT-412-CRO
ICN-412-A-623000-B-97499-00014-A-001-01
Figure 3. Main Rotor Controls Swashplate Inner Ring - Damage Repair Limits (Sheet 2 of 2)
412-A-62-30-00-05A-685A-B
Applicable to: ALL
Page 00084-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-00015-A-001-01
Figure 4. Main Rotor Controls Swashplate Outer Ring - Damage Repair Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-62-30-00-05A-685A-B
ECCN EAR99
31 MAY 2023 Page 00084-7
BHT-412-CRO
ICN-412-A-623000-B-97499-00016-A-001-01
Figure 5. Main Rotor Controls Bearing and Liner - Damage Repair Limits (Sheet 1 of 1)
412-A-62-30-00-05A-685A-B
Applicable to: ALL
Page 00084-8 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-00018-A-001-01
Figure 6. Main Rotor Controls Swashplate and Support Processing Requirements (Sheet 1 of 1)
Applicable to: ALL
412-A-62-30-00-05A-685A-B
ECCN EAR99
31 MAY 2023 Page 00084-9
BHT-412-CRO
ICN-412-A-623000-B-97499-00005-A-001-01
Figure 7. Main Rotor Controls Swashplate and Support Assembly (Sheet 1 of 3)
412-A-62-30-00-05A-685A-B
Applicable to: ALL
Page 00084-10 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-00006-A-001-01
Figure 7. Main Rotor Controls Swashplate and Support Assembly (Sheet 2 of 3)
Applicable to: ALL
412-A-62-30-00-05A-685A-B
ECCN EAR99
31 MAY 2023 Page 00084-11
BHT-412-CRO
ICN-412-A-623000-B-97499-00007-A-001-01
Figure 7. Main Rotor Controls Swashplate and Support Assembly (Sheet 3 of 3)
412-A-62-30-00-05A-685A-B
Applicable to: ALL
Page 00084-12 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-01115-A-001-01
Figure 8. Pivot Pin (412-010-422) - Damage Repair Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-62-30-00-05A-685A-B
ECCN EAR99
31 MAY 2023 Page 00084-13
BHT-412-CRO
ICN-412-A-623000-B-97499-01116-A-001-01
Figure 9. Pivot Pin (412-010-465) - Damage Repair Limits (Sheet 1 of 1)
412-A-62-30-00-05A-685A-B
Applicable to: ALL
Page 00084-14 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Controls Swashplate and Support - Assembly
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Grease
Corrosion preventive compound
Sealant
Drycleaning solvent
Sealant
Sealant
Adhesive
Denatured alcohol
Sealant
Sealant
Lockwire
Sealant
C-001
C-101
C-251
C-304
C-308
C-320
C-325
C-326
C-352
C-356
C-405
C-299
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
Remarks
Procedure
DO NOT DAMAGED SEALS DURING THE INSTALLATION. USE THE CORRECT SIZE PRESSING
PLUG.
NOTE
If corrosion protective oil has been applied to parts for long term storage, wash all parts with drycleaning
solvent (C-304) and dry with filtered compressed air. Do not immerse the bearings in solvent.
NOTE
Do not immerse shielded or sealed bearings in solvent. Wipe clean with solvent moistened cloth.
1.
ASB-412-08-131: Post: Install the seals (4 or 20, Figure 2) for the outer cap (11) and outer ring assembly (15) or
helicopters Post ASB 412-08-131, as follows:
NOTE
As shown in Figure 3, use sealant (C-251) or sealant (C-308) as an alternative for sealant (C-356) to
provide additional seal retaining strength. It is also permissible to apply a bead of sealant (C-251) or
sealant (C-308) to the upper seal (1) outer circumference and outer cap (2) inner diameter.
1.1.
Apply sealant (C-356) on the outside diameter of the upper seal (4, Figure 2, Detail D). Press the seal, with the seal
lip pointing down into the outer cap (11), until fully seated. Allow squeeze out to form a continuous bead around the
seal case. Remove any excess sealant.
NOTE
As shown in Figure 3, use sealant (C-251) or sealant (C-308) as an alternative to sealant (C-356) to give
more seal retaining strength.
1.2.
Apply sealant (C-356) on the outside diameter of the lower seal (20, Figure 2, Detail D). Press the seal in the outer
ring assembly (15) with the seal lip pointing down, into the lower side of the outer ring assembly, until fully seated.
Allow squeeze out to form a continuous bead around the seal case. Remove any excess sealant.
2.
Install the two trunnions (44) on the inner ring assembly (26) as follows:
Applicable to: ALL
412-A-62-30-00-05A-710A-B
ECCN EAR99
31 MAY 2023 Page 00085-1
BHT-412-CRO
EXCESSIVE SPREADING OF THE TRUNNION CLAMP AREA OF THE INNER RING COULD CAUSE
A CRACK RESULTING IN LOSS OF ROTOR CONTROL. INSERT TANGS OF WORKAID (Figure 4)
INTO SLOT AND TIGHTEN SCREW UNTIL TRUNNION CAN BARELY BE INSTALLED. IMMEDIATELY
RELEASE SCREW TENSION AND REMOVE WORKAID.
NOTE
A workaid is recommended to allow installation of trunnions with less possibility of damage to the inner
ring (Figure 4).
NOTE
Torque values are in addition to tare torques.
2.1.
Apply a light coat of corrosion preventive compound (C-101) to the barrel of the trunnion (44, Figure 2, Detail A)
and insert into the inner ring assembly (26).
2.2.
Install the spacer (43) and the plates (42 and 45) with three bolts (41), aluminum washers (39 and 40), and nuts (38).
Torque the nuts 50 to 70 inch-pounds (6 to 8 Nm) .
2.3.
Repeat the procedures for the remaining trunnion installation.
MAKE SURE THAT NO SEALANT GOES INTO THE BEARING OR DAMAGE TO THE BEARING CAN
OCCUR.
3.
For gimbal ring assembly (27) P/N 204-010-404-001, install the four new bearings (30) into the liners (29) as follows:
3.1.
Clean all faying surfaces with denatured alcohol (C-326).
3.2.
Apply a small quantity of sealant (C-352) or sealant (C-356) to the outside diameter of the bearing (30) and the
inside diameter of the liner (29).
3.3.
While sealant is still wet, install the bearing (30) in the liner (29). Clean excess sealant.
3.4.
Install the bearing liner assemblies on the gimbal ring assembly (27) and determine the shims required to center the
bearings between the bushings of mounting points as follows:
3.4.1.
Place two bearing and liner assemblies in opposite sides of the gimbal ring assembly (27) without the shims or
retaining screws.
3.4.2.
Mount the gimbal ring assembly (27) on the support assembly (37) with the bolts (32) inserted through the support
bushings and gimbal bearings. Tap the gimbal ring assembly to one side of the support assembly. Use a feeler gauge
at the opposite side to measure the clearance between the gimbal ring and bearing liner flange.
3.4.3.
Prepare two shims (28), each shim one-half as thick as the measured total clearance within 0.001 inch (0.03 mm).
3.4.4.
Match-mark the gimbal ring assembly (27) and support assembly (37) at one place. Remove the gimbal ring assembly.
3.4.5.
Remove both bearing and liner assemblies.
MAKE SURE THAT NO SEALANT GOES INTO THE BEARING OR DAMAGE TO THE BEARING CAN
OCCUR.
3.5.
Clean all the faying surfaces with denatured alcohol (C-326).
3.6.
Apply a small quantity of sealant (C-352) or sealant (C-356) to the faying surfaces of the bearing and liner assembly,
shims (28), gimbal ring assembly (27), and screws (31).
3.7.
While the sealant is still wet, position the bearing and liner assembly and the shim (28) on the gimbal ring assembly
(27) and install four screws (31). Tighten the screws.
412-A-62-30-00-05A-710A-B
Applicable to: ALL
Page 00085-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
3.8.
Safety the screws (31) together in pairs with lockwire (C-405).
3.9.
In the same manner shown in Step 3.4. through Step 3.7., fit and install the remaining two bearing and liner assemblies
in the gimbal ring assembly (27), to center the bearings in the mounting points of the inner ring assembly (26).
MAKE SURE THAT NO SEALANT GOES INTO THE BEARING OR DAMAGE TO THE BEARING CAN
OCCUR.
4.
For gimbal ring assembly (51) 212-010-416-101, install the four bearings (59) and liners (58) as follows:
4.1.
Clean all faying surfaces with denatured alcohol (C-326).
4.2.
Apply a small quantity of sealant (C-352) to the outside diameter of the bearing (59) and the inside diameter of
the liner (58).
4.3.
While sealant is still wet, install the bearing (59) in the liner (58). Clean excess sealant.
4.4.
Install the bearing liner assemblies on the gimbal ring assembly (51) and determine the shims required to center the
bearings between the bushings of mounting points as follows:
4.4.1.
Place two bearing and liner assemblies in opposite sides of the gimbal ring assembly (51) without the shims or
retaining screws.
4.4.2.
Mount the gimbal ring assembly (51) on the support assembly (37) with the bolts (32) inserted through the support
bushings and gimbal bearings. Tap the gimbal ring assembly to one side of the support assembly. Use a feeler gauge
at the opposite side to measure the clearance between the gimbal ring and bearing liner flange.
4.4.3.
Prepare two shims (52), each shim one-half as thick as the measured total clearance within 0.001 inch (0.03 mm).
4.4.4.
Match-mark the gimbal ring assembly (51) and support assembly (37) at one place. Remove the gimbal ring assembly.
4.4.5.
Remove both bearing and liner assemblies.
MAKE SURE THAT NO SEALANT GOES INTO THE BEARING OR DAMAGE TO THE BEARING CAN
OCCUR.
4.5.
Clean all the faying surfaces with denatured alcohol (C-326).
4.6.
Apply a small quantity of sealant (C-352) to the faying surfaces of the bearing and liner assembly, shims (28),
and gimbal ring assembly (51).
4.7.
Apply a small quantity of sealant (C-299) to the shank of the bolts (50).
4.8.
While the sealant is still wet, position the bearing and liner assembly and the shim (28) on the gimbal ring assembly
(51) with the four bolts (50). Tighten the bolts.
4.9.
Safety the bolts (50) together in pairs with lockwire (C-405).
4.10.
In the same manner shown in Step 4.4.1. through Step 4.8., fit and install the remaining two bearing and liner
assemblies in the gimbal ring assembly (51), to center the bearings in the mounting points of the inner ring assembly
(26).
Applicable: ASB-412-93-71: Post:
5.
Assemble the gimbal ring assembly (27 or 51), as applicable, to the support assembly (37) as follows:
5.1.
Apply sealant (C-320) to the shanks of the bolts (32), I.D. of the bearing (30) and bushings (56 and 57).
5.2.
Position the gimbal ring assembly (27 or 51), as applicable, to the mounting points of the support assembly (37),
observing match-marks. Install the bolts (32) with the washers (33) with the chamfer next to the bolt heads from
inboard through the support and bearing. Install the washers (34) and nuts (36). Torque the nuts 90 to 120
inch-pounds (10 to 14 Nm) and safety with the cotter pins (35).
Applicable: TB 412-92-113: Pre:
Applicable to: ALL
412-A-62-30-00-05A-710A-B
ECCN EAR99
31 MAY 2023 Page 00085-3
BHT-412-CRO
6.
Install the inner ring assembly (26) 204-011-402-125 on the gimbal ring assembly (27 or 51), as applicable, and
support assembly (37) as follows:
6.1.
Position the inner ring assembly (26) over the support assembly (37) with the control horns located as illustrated
and the gimbal ring assembly (27 or 51), as applicable, bearings aligned in the mounting points of the inner ring
assembly. Make sure that the control horn without trunnion is located nearest to the collective lever mounting
bosses of the support assembly.
6.2.
Apply sealant (C-320) to the shank of the bolts (25), I.D of the bearings (30 or 59) and bushings (48 and 49).
6.3.
Install two bushings (48) in the inner ring assembly (26). Install the bolts (25) with washers (24), chamfer next to
heads, from inboard through the bearing (30) and inner ring assembly.
6.4.
Install the washers (23) and nuts (22). Torque the nuts 90 to 120 inch-pounds (10 to 14 Nm) and install the cotter
pins (21).
Applicable: TB 412-92-113: Post:
7.
Install the inner ring assembly (26) 204-011-402-131 on the gimbal ring assembly (27 or 51), as applicable, and
support assembly (37) as follows:
7.1.
Apply sealant (C-320) to the shank of the bolts (25), I.D. of the bearings (30) and bushings (53, 54 and 55).
7.2.
Position the inner ring assembly (26) over the support assembly (37) with the control horns located as illustrated
and the gimbal ring assembly (27 or 51), as applicable, bearings aligned in the mounting points of the inner ring.
Make sure that the control horn without trunnion is located nearest to the collective lever mounting bosses of the
support assembly (37).
7.3.
Install the bolts (25) with washers (24), chamfer next to heads, from inboard through the bearing (30 or 59) and
inner ring assembly (26).
7.4.
Install the washers (23) and nuts (22). Torque the nuts 90 to 120 inch-pounds (10 to 14 Nm) and install the cotter
pins (21).
NOTE
After 30 minutes curing time, tilt the swashplate all directions to ensure there is no binding caused by
retaining compound entering gimbal bearings. Cure the sealant 1 to 2 hours at 75°F (24°C) (297.15°k)
before service use.
8.
Hand pack the bearing set (13) with grease (C-001).
9.
Apply light coatings of corrosion preventive compound (C-101) on the inside and outside diameters of the bearing set
(13) and on the mating surfaces of the outer ring (15) and liner on the inner ring (26).
10.
Temporarily install the bearing on the inner ring assembly. Determine the height of the bearing set (13) inner race
above the top surface of the inner ring (26) as outlined in Step 12.. Peel the four section shim (6) 0.009 to 0.012 inch
(0.23 to 0.30 mm) thinner than the measured dimension. Remove the bearing.
11.
Align the etched arrows on the bearing (13) as shown and install between the inner ring assembly (26) and outer ring
assembly (15). Tap evenly with a soft mallet until seated. Use care to prevent damage to the seal (20) in the outer ring.
12.
Determine the height of the bearing set outer race above the top surface of the outer ring assembly (15), either by
using a depth gauge or by placing the outer cap (11) on the bearing and measuring the gap with a feeler gauge.
Peel the new laminated shim (12) 0.009 to 0.012 inch (0.229 to 0.304 mm) thinner than the measured dimension
to provide clamp-up on the bearing race.
13.
Place the shim (6) sections on the inner ring assembly studs. Fill the gaps between the shim sections with corrosion
preventive compound (C-101). Put the inner cap (5) in position on the studs.
14.
Assemble the outer cap (11), shim (12), and outer ring assembly (15) as follows:
14.1.
Align the shim (12) over the holes and two bolts (14) in the outer ring assembly (15). Install the outer cap (11) with
the 14 bolts (9) pointing down, steel washers (10 and 18), and nuts (19).
14.2.
Install two nuts (7) and washers (8) on the bolts (14) pointing up.
14.3.
Torque the nuts (7 and 19) to 165 to 175 inch-pounds (19 to 20 Nm)
.
412-A-62-30-00-05A-710A-B
Applicable to: ALL
Page 00085-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
NOTE
The recommended grip length for bolts and threaded fasteners found in the BHT-ALL-SPM, Standard
Practices Manual is not applicable for this particular installation.
14.4.
Refer to Figure 1 to determine if the retaining bolts are in safety. The minimum protusion requirement is that the
entirety of the bolt chamfer be visible below the end of the retaining nuts.
14.5.
If the bolts are found not in safety. Replace the lower washers, one at a time, with thinner washers NAS1149F0532P.
15.
Install the cover (3) with the washers (2) and nuts (1). Torque the nuts 50 to 70 inch-pounds (6 to 8 Nm).
16.
Lubricate the trunnion assemblies (44) through the fittings with grease (C-001) until the grease vents past the
seals. Wipe off excess grease.
17.
Lubricate the swashplate through the fittings in the outer ring (15) with grease (C-001) until the grease vents past the
seals. Wipe off excess grease.
18.
Check the swashplate for freedom of movement in all directions.
19.
After assembly, coat all the bolt heads, washers, nuts, and exposed joints with corrosion preventive compound
(C-101).
Applicable to: ALL
412-A-62-30-00-05A-710A-B
ECCN EAR99
31 MAY 2023 Page 00085-5
BHT-412-CRO
ICN-412-A-623000-B-97499-00019-A-001-01
Figure 1. Swashplate Assembly - Bolts Grip Length (Sheet 1 of 1)
412-A-62-30-00-05A-710A-B
Applicable to: ALL
Page 00085-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-00005-A-001-01
Figure 2. Main Rotor Controls Swashplate and Support Assembly (Sheet 1 of 3)
Applicable to: ALL
412-A-62-30-00-05A-710A-B
ECCN EAR99
31 MAY 2023 Page 00085-7
BHT-412-CRO
ICN-412-A-623000-B-97499-00006-A-001-01
Figure 2. Main Rotor Controls Swashplate and Support Assembly (Sheet 2 of 3)
412-A-62-30-00-05A-710A-B
Applicable to: ALL
Page 00085-8 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-00007-A-001-01
Figure 2. Main Rotor Controls Swashplate and Support Assembly (Sheet 3 of 3)
Applicable to: ALL
412-A-62-30-00-05A-710A-B
ECCN EAR99
31 MAY 2023 Page 00085-9
BHT-412-CRO
ICN-412-A-623000-B-97499-00017-A-001-01
Figure 3. Alternate Method For Swashplate Seals Installation (Sheet 1 of 1)
412-A-62-30-00-05A-710A-B
Applicable to: ALL
Page 00085-10 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-00008-A-001-01
Figure 4. Workaid - Trunnion Removal and Installation (Sheet 1 of 1)
Applicable to: ALL
412-A-62-30-00-05A-710A-B
ECCN EAR99
31 MAY 2023 Page 00085-11
BHT-412-CRO
Intentionally blank page
412-A-62-30-00-05A-710A-B
Applicable to: ALL
Page 00085-12 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Controls Collective Lever (412-010-408-101) - Disassembly
Procedure
1.
Remove two bolts (2, Figure 1) and remove the trunnion assembly (4) from the collective lever assembly (1).
2.
Do not remove the bushings (7 and 8) unless the bushings are worn or damaged beyond limits. Refer to Figure 2 for
damage limits. Refer to 412-A-62-30-00-03A-685A-B / 00090 for repair procedures.
Applicable to: ALL
412-A-62-30-00-03A-530A-B
ECCN EAR99
31 MAY 2023 Page 00086-1
BHT-412-CRO
ICN-412-A-623000-B-97499-00020-A-001-01
Figure 1. Main Rotor Controls Collective Lever Assembly (Sheet 1 of 1)
412-A-62-30-00-03A-530A-B
Applicable to: ALL
Page 00086-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-00021-A-001-01
Figure 2. Main Rotor Controls Collective Lever Assembly - Damage Repair Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-62-30-00-03A-530A-B
ECCN EAR99
31 MAY 2023 Page 00086-3
BHT-412-CRO
Intentionally blank page
412-A-62-30-00-03A-530A-B
Applicable to: ALL
Page 00086-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Controls Collective Lever (412-010-408-101) - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Corrosion preventive oil
Drycleaning solvent
Barrier material
Barrier tape
C-126
C-304
C-427
C-456
AR
AR
AR
AR
Remarks
Procedure
DO NOT IMMERSE TRUNNION ASSEMBLY IN SOLVENT.
1.
Clean the collective lever assembly (1, Figure 1) with drycleaning solvent (C-304). Use a clean cloth dampened in
drycleaning solvent (C-304) to clean trunnion assembly (4).
2.
Dry parts with filtered, compressed air.
3.
Remove the finish from the collective lever (BHT-ALL-SPM, Standard Practices Manual).
4.
When the parts are not to be processed immediately after cleaning, apply corrosion preventive oil (C-126). Wrap
the parts in barrier material (C-427) and secure with barrier tape (C-456).
Applicable to: ALL
412-A-62-30-00-03A-258A-B
ECCN EAR99
31 MAY 2023 Page 00087-1
BHT-412-CRO
ICN-412-A-623000-B-97499-00020-A-001-01
Figure 1. Main Rotor Controls Collective Lever Assembly (412-010-408) (Sheet 1 of 1)
412-A-62-30-00-03A-258A-B
Applicable to: ALL
Page 00087-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Controls Collective Lever (412-010-408-101) - Inspection
Procedure
1.
Inspect the trunnion assembly (4, Figure 1) as follows:
NOTE
Trunnion bearings are different from other bearings that normally can be feel-checked for roughness and
ease of rotation. Trunnion bearings are preloaded into the cylinder portion of the trunnion with a 0.0005
inch (0.013 mm) tight to 0.005 inch (0.13 mm) loose tolerance. The feeling of roughness is due to the
preloaded and angular faces of the inner and outer races.
1.1.
Rotate the trunnion bearing and apply slight outward pressure to determine the trunnion bearing position where
maximum axial looseness can be felt.
1.2.
Measure axial play with the dial indicator. Maximum acceptable axial play is 0.019 inch (0.48 mm).
2.
Inspect the collective lever assembly (1, Figure 1) in accordance with Figure 2, ASB 412-11-148, and
412-A-62-30-00-03A-353A-B / 00089.
Applicable to: ALL
412-A-62-30-00-03A-280A-B
ECCN EAR99
31 MAY 2023 Page 00088-1
BHT-412-CRO
ICN-412-A-623000-B-97499-00020-A-001-01
Figure 1. Main Rotor Controls Collective Lever Assembly (412-010-408) (Sheet 1 of 1)
412-A-62-30-00-03A-280A-B
Applicable to: ALL
Page 00088-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-00021-A-001-01
Figure 2. Main Rotor Controls Collective Lever Assembly (412-010-408)- Damage Repair Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-62-30-00-03A-280A-B
ECCN EAR99
31 MAY 2023 Page 00088-3
BHT-412-CRO
Intentionally blank page
412-A-62-30-00-03A-280A-B
Applicable to: ALL
Page 00088-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Controls Collective Lever (412-010-408-101) - Non-destructive Inspection
Procedure
1.
Do a Fluorescent Penetrant Inspection (FPI) for the applicable parts shown in Table 1 in accordance with the
instructions provided in the BHT-ALL-SPM, Chapter 6, Standard Practices Manual.
2.
Discard all the parts that fail the Non-Destructive Inspection (NDI) criteria.
Table 1. Collective Lever - Non-Destructive Inspection
FIGURE NUMBER
NOMENCLATURE
PART NUMBER
Figure 1
Collective Lever
412-010-408
FLUORESCENT PENETRANT
INSPECTION
X
Applicable to: ALL
412-A-62-30-00-03A-353A-B
ECCN EAR99
31 MAY 2023 Page 00089-1
BHT-412-CRO
ICN-412-A-623000-B-97499-00021-A-001-01
Figure 1. Main Rotor Controls Collective Lever Assembly - Damage Repair Limits (Sheet 1 of 1)
412-A-62-30-00-03A-353A-B
Applicable to: ALL
Page 00089-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Controls Collective Lever (412-010-408-101) - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Epoxy polyamide primer
MEK
Abrasive cloth or paper
C-204
C-309
C-423
AR
AR
AR
Remarks
Procedure
1.
Replace the collective lever assembly (1, Figure 2) or trunnion assembly (4) if damaged or worn beyond limits
(Figure 1 and 412-A-62-30-00-03A-280A-B / 00088).
2.
Replace damaged or worn bushings (7 and 8, Figure 2) if required, as follows:
DO NOT EXCEED 200°F (93°C) ON COLLECTIVE LEVER WHILE REMOVING BUSHINGS.
2.1.
Heat the collective lever (1) and press out the bushings (7 and 8).
2.2.
Clean the collective lever bores with MEK (C-309) and inspect for scoring and cracks (Figure 1). Polish out acceptable
damage using fine to medium grade abrasive cloth or paper (C-423).
2.3.
Coat the mating surface of the bushings (7 and 8) and collective lever bores with epoxy polyamide primer (C-204).
DO NOT EXCEED 200°F (93°C) ON COLLECTIVE LEVER WHILE REMOVING BUSHINGS.
2.4.
Heat the collective lever (1) and install the bushings (7 and 8).
2.5.
Line ream the bushings (8) 0.875 to 0.876 inch (22.23 to 22.25 mm) parallel to the centerline of the bushings (7)
within 0.003 inch (0.08 mm).
3.
Polish out mechanical and corrosion damage that is within limits noted in Figure 1 on the collective lever assembly (1)
with fine to medium grade abrasive cloth or paper (C-423).
4.
Touch up areas where chemical film has been damaged, as shown in Figure 3.
5.
Touch up areas where cadmium plate has been damaged, as shown in Figure 3.
6.
Prime and paint the collective lever, as shown in Figure 3.
Applicable to: ALL
412-A-62-30-00-03A-685A-B
ECCN EAR99
31 MAY 2023 Page 00090-1
BHT-412-CRO
ICN-412-A-623000-B-97499-00021-A-001-01
Figure 1. Main Rotor Controls Collective Lever Assembly (412-010-408) - Damage Repair Limits (Sheet 1 of 1)
412-A-62-30-00-03A-685A-B
Applicable to: ALL
Page 00090-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-00020-A-001-01
Figure 2. Main Rotor Controls Collective Lever Assembly (412-010-408) (Sheet 1 of 1)
Applicable to: ALL
412-A-62-30-00-03A-685A-B
ECCN EAR99
31 MAY 2023 Page 00090-3
BHT-412-CRO
ICN-412-A-623000-B-97499-00022-A-001-01
Figure 3. Main Rotor Controls Collective Lever (412-010-408) Processing Requirements (Sheet 1 of 1)
412-A-62-30-00-03A-685A-B
Applicable to: ALL
Page 00090-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Controls Collective Lever (412-010-408-101) - Assembly
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Grease
Epoxy polyamide primer
C-001
C-204
AR
AR
Remarks
Procedure
1.
Coat the mating surface of the trunnion assembly (4, Figure 1) with epoxy polyamide primer (C-204) and position the
trunnion assembly in the collective lever assembly (1) as shown.
2.
Install the bolts (2), aluminum washers (3 and 5), and nuts (6). Torque nuts 50 to 70 inch-pounds (6 to 8 Nm).
APPLICATIONS WHERE GREASE (C-007) WAS USED HAS BEEN UPDATED TO USE GREASE
(C-001), HOWEVER THESE TWO GREASES CANNOT BE INTERMIXED. MAKE SURE ALL THE
OLD GREASE (C-007) HAS BEEN PURGED BEFORE YOU USE THE NEW GREASE (C-001).
3.
Purge lubricate the trunnion assembly (4) grease fitting with bearing grease (C-001). Wipe off excess grease.
Applicable to: ALL
412-A-62-30-00-03A-710A-B
ECCN EAR99
31 MAY 2023 Page 00091-1
BHT-412-CRO
ICN-412-A-623000-B-97499-00020-A-001-01
Figure 1. Main Rotor Controls Collective Lever Assembly (412-010-408) (Sheet 1 of 1)
412-A-62-30-00-03A-710A-B
Applicable to: ALL
Page 00091-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Controls Collective Lever (412-010-464-101) - Disassembly
Procedure
1.
Remove two bolts (2, Figure 1) and remove the trunnion assembly (4) from the collective lever assembly (1).
2.
Do not remove the bushings (7 and 8) unless the bushings are worn or damaged beyond limits. Refer to Figure 2 for
damage limits. Refer to 412-A-62-30-00-03B-685A-B / 00096 for repair procedures.
Applicable to: ALL
412-A-62-30-00-03B-530A-B
ECCN EAR99
31 MAY 2023 Page 00092-1
BHT-412-CRO
ICN-412-A-623000-B-97499-01117-A-001-01
Figure 1. Main Rotor Controls Collective Lever Assembly (412-010-464) (Sheet 1 of 1)
412-A-62-30-00-03B-530A-B
Applicable to: ALL
Page 00092-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-01118-A-001-01
Figure 2. Main Rotor Controls Collective Lever Assembly (412-010-464) — Damage Repair Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-62-30-00-03B-530A-B
ECCN EAR99
31 MAY 2023 Page 00092-3
BHT-412-CRO
Intentionally blank page
412-A-62-30-00-03B-530A-B
Applicable to: ALL
Page 00092-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Controls Collective Lever (412-010-464-101) - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Corrosion preventive oil
Drycleaning solvent
Barrier material
Barrier tape
C-126
C-304
C-427
C-456
AR
AR
AR
AR
Remarks
Procedure
DO NOT IMMERSE TRUNNION ASSEMBLY IN SOLVENT.
1.
Clean the collective lever assembly (1, Figure 1) with drycleaning solvent (C-304). Use a clean cloth dampened in
drycleaning solvent (C-304) to clean trunnion assembly (4).
2.
Dry parts with filtered, compressed air.
3.
Remove the finish from the collective lever (BHT-ALL-SPM, Standard Practices Manual).
4.
When the parts are not to be processed immediately after cleaning, apply corrosion preventive oil (C-126). Wrap
the parts inbarrier material (C-427) and secure with barrier tape (C-456).
Applicable to: ALL
412-A-62-30-00-03B-258A-B
ECCN EAR99
31 MAY 2023 Page 00093-1
BHT-412-CRO
ICN-412-A-623000-B-97499-01117-A-001-01
Figure 1. Main Rotor Controls Collective Lever Assembly (412-010-464) (Sheet 1 of 1)
412-A-62-30-00-03B-258A-B
Applicable to: ALL
Page 00093-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Controls Collective Lever (412-010-464-101) - Inspections
Procedure
1.
Inspect the trunnion assembly (4, Figure 1) as follows:
NOTE
Trunnion bearings are different from other bearings that normally can be feel-checked for roughness and
ease of rotation. Trunnion bearings are preloaded into the cylinder portion of the trunnion with a 0.0005
inch (0.013 mm) tight to 0.005 inch (0.13 mm) loose tolerance. The feeling of roughness is due to the
preloaded and angular faces of the inner and outer races.
1.1.
Rotate the trunnion bearing and apply slight outward pressure to determine the trunnion bearing position where
maximum axial looseness can be felt.
1.2.
Measure axial play with the dial indicator. Maximum acceptable axial play is 0.019 inch (0.48 mm).
2.
Inspect the collective lever assembly (1, Figure 1) in accordance with Figure 2, Alert Service Bulletin (ASB)
412-11-148, and 412-A-62-30-00-03B-353A-B / 00095.
Applicable to: ALL
412-A-62-30-00-03B-280A-B
ECCN EAR99
31 MAY 2023 Page 00094-1
BHT-412-CRO
ICN-412-A-623000-B-97499-01117-A-001-01
Figure 1. Main Rotor Controls Collective Lever Assembly (412-010-464) (Sheet 1 of 1)
412-A-62-30-00-03B-280A-B
Applicable to: ALL
Page 00094-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-01118-A-001-01
Figure 2. Main Rotor Controls Collective Lever Assembly (412-010-464) — Damage Repair Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-62-30-00-03B-280A-B
ECCN EAR99
31 MAY 2023 Page 00094-3
BHT-412-CRO
Intentionally blank page
412-A-62-30-00-03B-280A-B
Applicable to: ALL
Page 00094-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Controls Collective Lever (412-010-464-101) - Non-destructive Inspection
Procedure
1.
Do a Fluorescent Penetrant Inspection (FPI) for the applicable parts shown in Table 1 in accordance with the
instructions provided in the BHT-ALL-SPM, Chapter 6, Standard Practices Manual.
2.
Discard all the parts that fail the Non-Destructive Inspection (NDI) criteria.
Table 1. Collective Lever - Non-Destructive Inspection
FIGURE NUMBER
NOMENCLATURE
PART NUMBER
Figure 1
Collective Lever
412-010-464
FLUORESCENT PENETRANT
INSPECTION
X
Applicable to: ALL
412-A-62-30-00-03B-353A-B
ECCN EAR99
31 MAY 2023 Page 00095-1
BHT-412-CRO
ICN-412-A-623000-B-97499-01118-A-001-01
Figure 1. Main Rotor Controls Collective Lever Assembly (412-010-464) — Damage Repair Limits (Sheet 1 of 1)
412-A-62-30-00-03B-353A-B
Applicable to: ALL
Page 00095-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Controls Collective Lever (412-010-464-101) - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Epoxy polyamide primer
MEK
Abrasive cloth or paper
C-204
C-309
C-423
AR
AR
AR
Remarks
Procedure
1.
Replace the collective lever assembly (1, Figure 1) or trunnion assembly (4) if damaged or worn beyond limits (See
Figure 2 and 412-A-62-30-00-03B-280A-B / 00094).
2.
Replace damaged or worn bushings (7 and 8, Figure 1) if required, as follows:
DO NOT EXCEED 200°F (93°C) ON COLLECTIVE LEVER WHILE INSTALLING BUSHINGS.
2.1.
Heat the collective lever (1) and press out the bushings (7 and 8).
2.2.
Clean the collective lever bores with MEK (C-309) and inspect for scoring and cracks (See Figure 2). Polish out
acceptable damage using fine to medium grade abrasive cloth or paper (C-423).
2.3.
Coat the mating surface of the bushings (7 and 8, Figure 1) and collective lever bores with epoxy polyamide primer
(C-204).
DO NOT EXCEED 200°F (93°C) ON COLLECTIVE LEVER WHILE REMOVING BUSHINGS.
2.4.
Heat the collective lever (1) and install the bushings (7 and 8).
2.5.
Line ream the bushings (8) 0.875 to 0.876 inch (22.23 to 22.25 mm) parallel to the centerline of the bushings (7)
within 0.003 inch (0.08 mm).
3.
Polish out mechanical and corrosion damage that is within limits noted in Figure 2 on the collective lever assembly
(1, Figure 1) with fine to medium grade abrasive cloth or paper (C-423).
4.
Do the touch up of chemical film or anodize as applicable, as shown in Figure 3.
5.
Touch up areas where cadmium plate has been damaged, as shown in Figure 3.
6.
Prime and paint the collective lever, as shown in Figure 3.
Applicable to: ALL
412-A-62-30-00-03B-685A-B
ECCN EAR99
31 MAY 2023 Page 00096-1
BHT-412-CRO
ICN-412-A-623000-B-97499-01117-A-001-01
Figure 1. Main Rotor Controls Collective Lever Assembly (412-010-464) (Sheet 1 of 1)
412-A-62-30-00-03B-685A-B
Applicable to: ALL
Page 00096-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-623000-B-97499-01118-A-001-01
Figure 2. Main Rotor Controls Collective Lever Assembly (412-010-464) — Damage Repair Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-62-30-00-03B-685A-B
ECCN EAR99
31 MAY 2023 Page 00096-3
BHT-412-CRO
ICN-412-A-623000-B-97499-01119-A-001-01
Figure 3. Main Rotor Controls Collective Lever (412-010-464) Processing Requirements (Sheet 1 of 1)
412-A-62-30-00-03B-685A-B
Applicable to: ALL
Page 00096-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Rotor Controls Collective Lever (412-010-464-101) - Assembly
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Grease
Epoxy polyamide primer
C-001
C-204
AR
AR
Remarks
Procedure
1.
Coat the mating surface of the trunnion assembly (4, Figure 1) with epoxy polyamide primer (C-204) and position the
trunnion assembly in the collective lever assembly (1) as shown.
2.
Install the bolts (2), aluminum washers (3 and 5), and nuts (6). Torque nuts 50 to 70 inch-pounds (6 to 8 Nm).
APPLICATIONS WHERE GREASE (C-007) WAS USED HAS BEEN UPDATED TO USE GREASE
(C-001), HOWEVER THESE TWO GREASES CANNOT BE INTERMIXED. MAKE SURE ALL THE
OLD GREASE (C-007) HAS BEEN PURGED BEFORE YOU USE THE NEW GREASE (C-001).
3.
Purge lubricate the trunnion assembly (4) grease fitting with bearing grease (C-001). Wipe off excess grease.
Applicable to: ALL
412-A-62-30-00-03B-710A-B
ECCN EAR99
31 MAY 2023 Page 00097-1
BHT-412-CRO
ICN-412-A-623000-B-97499-01117-A-001-01
Figure 1. Main Rotor Controls Collective Lever Assembly (412-010-464) (Sheet 1 of 1)
412-A-62-30-00-03B-710A-B
Applicable to: ALL
Page 00097-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
CHAPTER 63
MAIN ROTOR DRIVE
COMPONENT REPAIR AND OVERHAUL MANUAL
Applicable to: ALL
412-A-63-00-00-00A-009A-A
ECCN EAR99
28 OCT 2024 Page 00098-1
BHT-412-CRO
Intentionally blank page
412-A-63-00-00-00A-009A-A
Applicable to: ALL
Page 00098-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
List of Effective Data Modules
The listed documents are included in issue 003, dated 2024-10-28, of this publication.
C = Changed data module, N = New data module
Document title
Data module code / Seq number
Issue date
Applicable
to
Main Driveshaft (212-040-005-103) - Disassembly DMC-412-A-63-10-00-00A-530A-B /
00099
C 2024-10-28
ALL
Main Driveshaft (212-040-005-103) - Cleaning
DMC-412-A-63-10-00-00A-258A-B /
00100
C 2024-10-28
ALL
Main Driveshaft (212-040-005-103) - Inspection
DMC-412-A-63-10-00-00A-280A-B /
00101
C 2024-10-28
ALL
Main Driveshaft (212-040-005-103) - Conditional
Inspection
DMC-412-A-63-10-00-00A-284A-B /
00102
C 2024-10-28
ALL
Main Driveshaft (212-040-005-103) - Normal
Inspection
DMC-412-A-63-10-00-00A-280B-B /
00103
C 2024-10-28
ALL
Main Driveshaft (212-040-005-103) - Repair
DMC-412-A-63-10-00-00A-685A-B /
00104
C 2024-10-28
ALL
Main Driveshaft (212-040-005-103) - Lubrication
DMC-412-A-63-10-00-00A-240A-B /
00105
C 2024-10-28
ALL
Main Driveshaft (212-040-005-103) - Assembly
DMC-412-A-63-10-00-00A-710A-B /
00106
C 2024-10-28
ALL
Main Driveshaft (412-040-005-101 and -103) Disassembly
DMC-412-A-63-10-00-02A-530A-B /
00107
C 2024-10-28
SN: 3602036999 or
3700237999 or
SN: 3800138999 or
3910139999 or
SN: 4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
Main Driveshaft (412-040-005-101 and -103) Cleaning
DMC-412-A-63-10-00-02A-258A-B /
00108
C 2024-10-28
SN: 3602036999 or
3700237999 or
SN: 3800138999 or
3910139999 or
SN: 4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
Applicable to: ALL
ECCN EAR99
412-A-63-00-00-00A-00SA-A
28 OCT 2024 Page 1
BHT-412-CRO
Document title
Data module code / Seq number
Issue date
Applicable
to
Main Driveshaft (412-040-005-101 and -103) Inspection
DMC-412-A-63-10-00-02A-280A-B /
00109
C 2024-10-28
SN: 3602036999 or
3700237999 or
SN: 3800138999 or
3910139999 or
SN: 4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
Main Driveshaft (412-040-005-101 and -103) Conditional Inspection
DMC-412-A-63-10-00-02A-284A-B /
00110
C 2024-10-28
SN: 3602036999 or
3700237999 or
SN: 3800138999 or
3910139999 or
SN: 4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
Main Driveshaft (412-040-005-101 and -103) Normal Inspection
DMC-412-A-63-10-00-02A-280B-B /
00111
C 2024-10-28
SN: 3602036999 or
3700237999 or
SN: 3800138999 or
3910139999 or
SN: 4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
412-A-63-00-00-00A-00SA-A
Page 2 28 OCT 2024
Applicable to: ALL
ECCN EAR99
BHT-412-CRO
Document title
Data module code / Seq number
Issue date
Applicable
to
Main Driveshaft (412-040-005-101 and -103) Repair
DMC-412-A-63-10-00-02A-685A-B /
00112
C 2024-10-28
SN: 3602036999 or
3700237999 or
SN: 3800138999 or
3910139999 or
SN: 4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
Main Driveshaft (412-040-005-101 and -103) Lubrication
DMC-412-A-63-10-00-02A-240A-B /
00113
C 2024-10-28
SN: 3602036999 or
3700237999 or
SN: 3800138999 or
3910139999 or
SN: 4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
Main Driveshaft (412-040-005-101 and -103) Assembly
DMC-412-A-63-10-00-02A-710A-B /
00114
C 2024-10-28
SN: 3602036999 or
3700237999 or
SN: 3800138999 or
3910139999 or
SN: 4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
Mast Assembly - Configuration
DMC-412-A-63-10-00-00A-398A-B /
00115
2023-05-31
ALL
Transmission Main Rotor Mast Assemblies
(412-040-366-103/-105 and -125) - Disassembly
DMC-412-A-63-10-00-04A-530A-B /
00116
2023-05-31
ALL
Transmission Main Rotor Mast Assemblies
(412-040-366-103/-105 and -125) - Cleaning
DMC-412-A-63-10-00-04A-258A-B /
00117
2023-05-31
ALL
Transmission Main Rotor Mast Assemblies
(412-040-366-103/-105 and -125) - Inspection
DMC-412-A-63-10-00-04A-280A-B /
00118
2023-05-31
ALL
Transmission Main Rotor Mast Assemblies
(412-040-366-103/-105 and -125) - Repair
DMC-412-A-63-10-00-04A-685A-B /
00119
2023-05-31
ALL
Applicable to: ALL
ECCN EAR99
412-A-63-00-00-00A-00SA-A
28 OCT 2024 Page 3
BHT-412-CRO
Document title
Data module code / Seq number
Issue date
Applicable
to
Transmission Main Rotor Mast Assemblies
(412-040-366-103/-105 and -125) - Assembly
DMC-412-A-63-10-00-04A-710A-B /
00120
2023-05-31
ALL
Transmission Main Rotor Mast Assemblies
(412-040-366-109 and Subsequent) Disassembly
DMC-412-A-63-10-00-05A-530A-B /
00121
C 2024-10-28
SN: 3602036999 or
3700237999 or
4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
Transmission Main Rotor Mast Assemblies
(412-040-366-109 and Subsequent) - Cleaning
DMC-412-A-63-10-00-05A-258A-B /
00122
C 2024-10-28
SN: 3602036999 or
3700237999 or
4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
Transmission Main Rotor Mast Assemblies
(412-040-366-109 and Subsequent) - Inspection
DMC-412-A-63-10-00-05A-280A-B /
00123
C 2024-10-28
SN: 3602036999 or
3700237999 or
4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
Transmission Main Rotor Mast Assemblies
(412-040-366-109 and Subsequent) - Repair
DMC-412-A-63-10-00-05A-685A-B /
00124
2023-05-31
SN: 3602036999 or
3700237999 or
4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
412-A-63-00-00-00A-00SA-A
Page 4 28 OCT 2024
Applicable to: ALL
ECCN EAR99
BHT-412-CRO
Document title
Data module code / Seq number
Issue date
Applicable
to
Transmission Main Rotor Mast Assemblies
(412-040-366-109 and Subsequent) - Assembly
DMC-412-A-63-10-00-05A-710A-B /
00125
C 2024-10-28
SN: 3602036999 or
3700237999 or
4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
Transmission (412-040-002, 412-040-004,
412-040-007 and 412-040-802) - General
DMC-412-A-63-10-00-06A-042A-B /
00126
2023-11-14
ALL
Transmission - Disassembly
DMC-412-A-63-10-00-06A-530A-B /
00127
C 2024-10-28
ALL
Transmission - Cleaning
DMC-412-A-63-10-00-06A-258A-B /
00128
2023-05-31
ALL
Transmission - Inspection
DMC-412-A-63-10-00-06A-280A-B /
00129
2023-05-31
ALL
Transmission - Conditional Inspection
DMC-412-A-63-10-00-06A-284A-B /
00130
2023-05-31
ALL
Transmission - Normal Inspection
DMC-412-A-63-10-00-06A-280B-B /
00131
2023-05-31
ALL
Transmission - Repair
DMC-412-A-63-10-00-06A-685A-B /
00132
2023-05-31
ALL
Transmission - Assembly
DMC-412-A-63-10-00-06A-710A-B /
00133
C 2024-10-28
ALL
Transmission - Run-in and Test
DMC-412-A-63-10-00-06A-320A-B /
00134
2023-05-31
ALL
Transmission - Sealing and Painting
DMC-412-A-63-10-00-06A-257A-B /
00135
2023-05-31
ALL
Transmission Case - General
DMC-412-A-63-10-00-00A-028A-B /
00136
2023-05-31
ALL
Transmission Top Case (212-040-059-101) Disassembly
DMC-412-A-63-10-00-08A-530A-B /
00137
2023-05-31
ALL
Transmission Top Case (212-040-059-101) Cleaning
DMC-412-A-63-10-00-08A-258A-B /
00138
2023-05-31
ALL
Transmission Top Case (212-040-059-101) Inspection
DMC-412-A-63-10-00-08A-280A-B /
00139
2023-05-31
ALL
Transmission Top Case (212-040-059-101) Repair
DMC-412-A-63-10-00-08A-685A-B /
00140
2023-05-31
ALL
Transmission Top Case (212-040-059-101) Assembly
DMC-412-A-63-10-00-08A-710A-B /
00141
2023-05-31
ALL
Transmission Main Bevel Gear Case
(212-040-053-009) - Disassembly
DMC-412-A-63-10-00-09A-530A-B /
00142
2023-05-31
ALL
Transmission Main Bevel Gear Case
(212-040-053-009) - Cleaning
DMC-412-A-63-10-00-09A-258A-B /
00143
2023-05-31
ALL
Transmission Main Bevel Gear Case
(212-040-053-009) - Inspection
DMC-412-A-63-10-00-09A-280A-B /
00144
2023-05-31
ALL
Transmission Main Bevel Gear Case
(212-040-053-009) - Repair
DMC-412-A-63-10-00-09A-685A-B /
00145
2023-05-31
ALL
Applicable to: ALL
ECCN EAR99
412-A-63-00-00-00A-00SA-A
28 OCT 2024 Page 5
BHT-412-CRO
Document title
Data module code / Seq number
Issue date
Applicable
to
Transmission Main Bevel Gear Case
(212-040-053-009) - Assembly
DMC-412-A-63-10-00-09A-710A-B /
00146
2023-05-31
ALL
Transmission Main Support Case
(212-040-054-013, -101, -105, -109 and
-117) - Disassembly
DMC-412-A-63-10-00-10A-530A-B /
00147
C 2024-10-28
ALL
Transmission Main Support Case
(212-040-054-013, -101, -105, -109 and
-117) - Cleaning
DMC-412-A-63-10-00-10A-258A-B /
00148
C 2024-10-28
ALL
Transmission Main Support Case
(212-040-054-013, -101, -105, -109 and
-117) - Inspection
DMC-412-A-63-10-00-10A-280A-B /
00149
C 2024-10-28
ALL
Transmission Main Support Case
(212-040-054-013, -101, -105, -109 and
-117) - Repair
DMC-412-A-63-10-00-10A-685A-B /
00150
C 2024-10-28
ALL
Transmission Main Support Case
(212-040-054-013, -101, -105, -109 and
-117) - Assembly
DMC-412-A-63-10-00-10A-710A-B /
00151
C 2024-10-28
ALL
Planetary Ring Gear, Upper Planetary, and Lower DMC-412-A-63-10-00-02A-028A-B /
Planetary Assemblies - Description
00152
2023-05-31
ALL
Planetary Ring Gear (205-040-231-009) Disassembly
DMC-412-A-63-10-00-11A-530A-B /
00153
2023-05-31
ALL
Planetary Ring Gear (205-040-231-009) Cleaning
DMC-412-A-63-10-00-11A-258A-B /
00154
2023-05-31
ALL
Planetary Ring Gear (205-040-231-009) Inspection
DMC-412-A-63-10-00-11A-280A-B /
00155
2023-05-31
ALL
Planetary Ring Gear (205-040-231-009) - Repair
DMC-412-A-63-10-00-11A-685A-B /
00156
2023-05-31
ALL
Planetary Ring Gear (205-040-231-009) Assembly
DMC-412-A-63-10-00-11A-710A-B /
00157
2023-05-31
ALL
Upper Planetary Assembly (204-040-360-005,
-103, -105 And 412-040-360-101) - Disassembly
DMC-412-A-63-10-00-12A-530A-B /
00158
C 2024-10-28
ALL
Upper Planetary Assembly (204-040-360-005,
-103, -105 and 412-040-360-101) - Cleaning
DMC-412-A-63-10-00-12A-258A-B /
00159
C 2024-10-28
ALL
Upper Planetary Assembly (204-040-360-005,
-103, -105 And 412-040-360-101) - Inspection
DMC-412-A-63-10-00-12A-280A-B /
00160
C 2024-10-28
ALL
Upper Planetary Assembly (204-040-360-005,
-103, -105 And 412-040-360-101) - Repair
DMC-412-A-63-10-00-12A-685A-B /
00161
C 2024-10-28
ALL
Upper Planetary Assembly (204-040-360-005,
-103, -105 And 412-040-360-101) - Assembly
DMC-412-A-63-10-00-12A-710A-B /
00162
C 2024-10-28
ALL
Lower Planetary Assembly - Disassembly
DMC-412-A-63-10-00-13A-530A-B /
00163
2023-05-31
ALL
Lower Planetary Assembly - Cleaning
DMC-412-A-63-10-00-13A-258A-B /
00164
2023-05-31
ALL
Lower Planetary Assembly - Inspection
DMC-412-A-63-10-00-13A-280A-B /
00165
2023-05-31
ALL
Lower Planetary Assembly - Repair
DMC-412-A-63-10-00-13A-685A-B /
00166
2023-05-31
ALL
Lower Planetary Assembly - Assembly
DMC-412-A-63-10-00-13A-710A-B /
00167
C 2024-10-28
ALL
Main Input Gear Quill (204-040-362-103) Disassembly
DMC-412-A-63-10-00-14A-530A-B /
00168
C 2024-10-28
ALL
412-A-63-00-00-00A-00SA-A
Page 6 28 OCT 2024
Applicable to: ALL
ECCN EAR99
BHT-412-CRO
Document title
Data module code / Seq number
Main Input Gear Quill (204-040-362-103) Cleaning
DMC-412-A-63-10-00-14A-258A-B /
00169
C 2024-10-28
ALL
Main Input Gear Quill (204-040-362-103) Inspection
DMC-412-A-63-10-00-14A-280A-B /
00170
C 2024-10-28
ALL
Main Input Gear Quill (204-040-362-103) - Repair DMC-412-A-63-10-00-14A-685A-B /
00171
C 2024-10-28
ALL
Main Input Gear Quill (204-040-362-103) Assembly
DMC-412-A-63-10-00-14A-710A-B /
00172
C 2024-10-28
ALL
Main Input Gear Quill (412-040-362-101, -103
and -105) - Disassembly
DMC-412-A-63-10-00-15A-530A-B /
00173
C 2024-10-28
SN: 3602036999 or
3700237999 or
SN: 3800138999 or
3910139999 or
SN: 4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
Main Input Gear Quill (412-040-362-101, -103
and -105) - Cleaning
DMC-412-A-63-10-00-15A-258A-B /
00174
C 2024-10-28
SN: 3602036999 or
3700237999 or
3800138999 or
3910139999 or
SN: 4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
Main Input Gear Quill (412-040-362-101, -103
and -105) - Inspection
DMC-412-A-63-10-00-15A-280A-B /
00175
C 2024-10-28
SN: 3602036999 or
3700237999 or
SN: 3800138999 or
3910139999 or
SN: 4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
Applicable to: ALL
ECCN EAR99
Issue date
Applicable
to
412-A-63-00-00-00A-00SA-A
28 OCT 2024 Page 7
BHT-412-CRO
Document title
Data module code / Seq number
Issue date
Applicable
to
Main Input Gear Quill (412-040-362-101, -103
and -105) - Repair
DMC-412-A-63-10-00-15A-685A-B /
00176
C 2024-10-28
SN: 3602036999 or
3700237999 or
3800138999 or
3910139999 or
SN: 4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
Main Input Gear Quill (412-040-362-101, -103
and -105) - Assembly
DMC-412-A-63-10-00-15A-710A-B /
00177
C 2024-10-28
SN: 3602036999 or
3700237999 or
SN: 3800138999 or
3910139999 or
SN: 4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
Main Input Quill (212-040-263-107) - Disassembly DMC-412-A-63-10-00-16A-530A-B /
00178
C 2024-10-28
ALL
Main Input Quill (212-040-263-107) - Cleaning
DMC-412-A-63-10-00-16A-258A-B /
00179
C 2024-10-28
ALL
Main Input Quill (212-040-263-107) - Inspection
DMC-412-A-63-10-00-16A-280A-B /
00180
C 2024-10-28
ALL
Main Input Quill (212-040-263-107) - Repair
DMC-412-A-63-10-00-16A-685A-B /
00181
C 2024-10-28
ALL
Main Input Quill (212-040-263-107) - Assembly
DMC-412-A-63-10-00-16A-710A-B /
00182
C 2024-10-28
ALL
Main Input Quill (212-040-263-101) - Disassembly DMC-412-A-63-10-00-17A-530A-B /
00183
C 2024-10-28
ALL
Main Input Quill (212-040-263-101) - Cleaning
DMC-412-A-63-10-00-17A-258A-B /
00184
2023-05-31
ALL
Main Input Quill (212-040-263-101) - Inspection
DMC-412-A-63-10-00-17A-280A-B /
00185
C 2024-10-28
ALL
Main Input Quill (212-040-263-101) - Repair
DMC-412-A-63-10-00-17A-685A-B /
00186
C 2024-10-28
ALL
Main Input Quill (212-040-263-101) - Assembly
DMC-412-A-63-10-00-17A-710A-B /
00187
C 2024-10-28
ALL
412-A-63-00-00-00A-00SA-A
Page 8 28 OCT 2024
Applicable to: ALL
ECCN EAR99
BHT-412-CRO
Document title
Issue date
Applicable
to
Main Input Quill (412-040-263-ALL) - Disassembly DMC-412-A-63-10-00-18A-530A-B /
00188
C 2024-10-28
SN: 3602036999 or
3700237999 or
SN: 3800138999 or
3910139999 or
SN: 4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
Main Input Quill (412-040-263-ALL) - Cleaning
DMC-412-A-63-10-00-18A-258A-B /
00189
C 2024-10-28
SN: 3602036999 or
3700237999 or
SN: 3800138999 or
3910139999 or
SN: 4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
Main Input Quill (412-040-263-ALL) - Inspection
DMC-412-A-63-10-00-18A-280A-B /
00190
C 2024-10-28
SN: 3602036999 or
3700237999 or
SN: 3800138999 or
3910139999 or
SN: 4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
Applicable to: ALL
ECCN EAR99
Data module code / Seq number
412-A-63-00-00-00A-00SA-A
28 OCT 2024 Page 9
BHT-412-CRO
Document title
Data module code / Seq number
Issue date
Applicable
to
Main Input Quill (412-040-263-ALL) - Repair
DMC-412-A-63-10-00-18A-685A-B /
00191
C 2024-10-28
SN: 3602036999 or
3700237999 or
SN: 3800138999 or
3910139999 or
SN: 4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
Main Input Quill (412-040-263-ALL) - Assembly
DMC-412-A-63-10-00-18A-710A-B /
00192
C 2024-10-28
SN: 3602036999 or
3700237999 or
SN: 3800138999 or
3910139999 or
SN: 4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
Generator (or SYS 2 Hydraulic Pump) Drive Quill DMC-412-A-63-10-00-19A-530A-B /
(204-040-379-003 and -101) - Disassembly
00193
2023-05-31
ALL
Generator (or SYS 2 Hydraulic Pump) Drive Quill DMC-412-A-63-10-00-19A-258A-B /
(204-040-379-003 and -101) - Cleaning
00194
2023-05-31
ALL
Generator (or SYS 2 Hydraulic Pump) Drive Quill DMC-412-A-63-10-00-19A-280A-B /
(204-040-379-003 and -101) - Inspection
00195
2023-05-31
ALL
Generator (or SYS 2 Hydraulic Pump) Drive Quill DMC-412-A-63-10-00-19A-685A-B /
(204-040-379-003 and -101) - Repair
00196
2023-05-31
ALL
Generator (or SYS 2 Hydraulic Pump) Drive Quill DMC-412-A-63-10-00-19A-710A-B /
(204-040-379-003 and -101) - Assembly
00197
2023-05-31
ALL
Offset Accessory Drive Quill (212-040-208-003
and -101) - Disassembly
DMC-412-A-63-10-00-20A-530A-B /
00198
2023-05-31
ALL
Offset Accessory Drive Quill (212-040-208-003
and -101) - Cleaning
DMC-412-A-63-10-00-20A-258A-B /
00199
2023-05-31
ALL
Offset Accessory Drive Quill (212-040-208-003
and -101) - Inspection
DMC-412-A-63-10-00-20A-280A-B /
00200
2023-05-31
ALL
Offset Accessory Drive Quill (212-040-208-003
and -101) - Repair
DMC-412-A-63-10-00-20A-685A-B /
00201
2023-05-31
ALL
Offset Accessory Drive Quill (212-040-208-003
and -101) - Assembly
DMC-412-A-63-10-00-20A-710A-B /
00202
2023-05-31
ALL
Accessory and Tail Rotor Drive and Sump
Assembly (212-040-365-105, -109, and -111) Disassembly
DMC-412-A-63-10-00-21A-530A-B /
00203
2023-05-31
ALL
412-A-63-00-00-00A-00SA-A
Page 10 28 OCT 2024
Applicable to: ALL
ECCN EAR99
BHT-412-CRO
Document title
Data module code / Seq number
Issue date
Applicable
to
Accessory and Tail Rotor Drive and Sump
Assembly (212-040-365-105, -109, and -111) Cleaning - Cleaning
DMC-412-A-63-10-00-21A-258A-B /
00204
2023-05-31
ALL
Accessory and Tail Rotor Drive and Sump
Assembly (212-040-365-105, -109, and -111) Conditional Inspection
DMC-412-A-63-10-00-21A-284A-B /
00205
2023-05-31
ALL
Accessory and Tail Rotor Drive and Sump
Assembly (212-040-365-105, -109, and -111) Normal Inspection
DMC-412-A-63-10-00-21A-280A-B /
00206
2023-05-31
ALL
Accessory and Tail Rotor Drive and Sump
Assembly (212-040-365-105, -109, and -111) Repair
DMC-412-A-63-10-00-21A-685A-B /
00207
2023-05-31
ALL
Accessory and Tail Rotor Drive and Sump
Assembly (212-040-365-105, -109, and -111) Assembly
DMC-412-A-63-10-00-21A-710A-B /
00208
2023-05-31
ALL
Rotary Oil Pump - Disassembly
DMC-412-A-63-10-00-22A-530A-B /
00209
2023-05-31
ALL
Rotary Oil Pump - Cleaning
DMC-412-A-63-10-00-22A-258A-B /
00210
2023-05-31
ALL
Rotary Oil Pump - Inspection
DMC-412-A-63-10-00-22A-280A-B /
00211
2023-05-31
ALL
Rotary Oil Pump - Repair
DMC-412-A-63-10-00-22A-685A-B /
00212
2023-05-31
ALL
Rotary Oil Pump - Assembly
DMC-412-A-63-10-00-22A-710A-B /
00213
2023-05-31
ALL
Oil Filter (Internal) (02W101633) - Disassembly
DMC-412-A-63-10-00-23A-530A-B /
00214
2023-05-31
ALL
Oil Filter (Internal) (02W101633) - Cleaning
DMC-412-A-63-10-00-23A-258A-B /
00215
2023-05-31
ALL
Oil Filter (Internal) (02W101633) - Inspection
DMC-412-A-63-10-00-23A-280A-B /
00216
2023-05-31
ALL
Oil Filter (Internal) (02W101633) - Repair
DMC-412-A-63-10-00-23A-685A-B /
00217
2023-05-31
ALL
Oil Filter (Internal) (02W101633) - Assembly
DMC-412-A-63-10-00-23A-710A-B /
00218
2023-05-31
ALL
Full Flow Debris Monitor (212-040-122-101 and
-103) - Disassembly
DMC-412-A-63-10-00-24A-530A-B /
00219
C 2024-10-28
ALL
Full Flow Debris Monitor (212-040-122-101 and
-103) - Cleaning
DMC-412-A-63-10-00-24A-258A-B /
00220
2023-11-14
ALL
Full Flow Debris Monitor (212-040-122-101 and
-103) - Inspection
DMC-412-A-63-10-00-24A-280A-B /
00221
2023-11-14
ALL
Full Flow Debris Monitor (212-040-122-101 and
-103) - Repair
DMC-412-A-63-10-00-24A-685A-B /
00222
2023-11-14
ALL
Full Flow Debris Monitor (212-040-122-101 and
-103) - Assembly
DMC-412-A-63-10-00-24A-710A-B /
00223
C 2024-10-28
ALL
Accessory and Tail Rotor Drive Quill
(212-040-365-023 and -115) - Disassembly
DMC-412-A-63-10-00-25A-530A-B /
00224
2023-05-31
ALL
Accessory and Tail Rotor Drive Quill
(212-040-365-023 and -115) - Cleaning
DMC-412-A-63-10-00-25A-258A-B /
00225
2023-05-31
ALL
Accessory and Tail Rotor Drive Quill
(212-040-365-023 and -115) - Inspection
DMC-412-A-63-10-00-25A-280A-B /
00226
C 2024-10-28
ALL
Applicable to: ALL
ECCN EAR99
412-A-63-00-00-00A-00SA-A
28 OCT 2024 Page 11
BHT-412-CRO
Document title
Data module code / Seq number
Issue date
Applicable
to
Accessory and Tail Rotor Drive Quill
(212-040-365-023 and -115) - Repair
DMC-412-A-63-10-00-25A-685A-B /
00227
2023-05-31
ALL
Accessory and Tail Rotor Drive Quill
(212-040-365-023 and -115) - Assembly
DMC-412-A-63-10-00-25A-710A-B /
00228
2023-05-31
ALL
Tail Rotor Drive Quill (212-040-365-025) Disassembly
DMC-412-A-63-10-00-26A-530A-B /
00229
C 2024-10-28
ALL
Tail Rotor Drive Quill (212-040-365-025) Cleaning
DMC-412-A-63-10-00-26A-258A-B /
00230
C 2024-10-28
ALL
Tail Rotor Drive Quill (212-040-365-025) Inspection
DMC-412-A-63-10-00-26A-280A-B /
00231
C 2024-10-28
ALL
Tail Rotor Drive Quill (212-040-365-025) - Repair
DMC-412-A-63-10-00-26A-685A-B /
00232
C 2024-10-28
ALL
Tail Rotor Drive Quill (212-040-365-025) Assembly
DMC-412-A-63-10-00-26A-710A-B /
00233
C 2024-10-28
ALL
Tail Rotor Drive Quill (212-040-365-113 AND
-135) - Disassembly
DMC-412-A-63-10-00-27A-530A-B /
00234
C 2024-10-28
SN: 3602036999 or
3700237999 or
3800138999 or
3910139999 or
SN: 4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
Tail Rotor Drive Quill (212-040-365-113 AND
-135) - Cleaning
DMC-412-A-63-10-00-27A-258A-B /
00235
C 2024-10-28
SN: 3602036999 or
3700237999 or
3800138999 or
3910139999 or
SN: 4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
412-A-63-00-00-00A-00SA-A
Page 12 28 OCT 2024
Applicable to: ALL
ECCN EAR99
BHT-412-CRO
Document title
Data module code / Seq number
Issue date
Applicable
to
Tail Rotor Drive Quill (212-040-365-113 AND
-135) - Inspection
DMC-412-A-63-10-00-27A-280A-B /
00236
C 2024-10-28
SN: 3602036999 or
3700237999 or
3800138999 or
3910139999 or
SN: 4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
Tail Rotor Drive Quill (212-040-3645-113 AND
-135) - Repair
DMC-412-A-63-10-00-27A-685A-B /
00237
C 2024-10-28
SN: 3602036999 or
3700237999 or
3800138999 or
3910139999 or
SN: 4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
Tail Rotor Drive Quill (212-040-365-113 AND
-135) - Assembly
DMC-412-A-63-10-00-27A-710A-B /
00238
C 2024-10-28
SN: 3602036999 or
3700237999 or
3800138999 or
3910139999 or
SN: 4640046499 or
412-570001-103:
Installed
or BHT412-SI-74:
Installed
Single Boost (or System 1) Hydraulic Drive Quill
(212-040-365-103) - Disassembly
DMC-412-A-63-10-00-28A-530A-B /
00239
2023-05-31
ALL
Single Boost (or System 1) Hydraulic Drive Quill
(212-040-365-103) - Cleaning
DMC-412-A-63-10-00-28A-258A-B /
00240
2023-05-31
ALL
Single Boost (or System 1) Hydraulic Drive Quill
(212-040-365-103) - Inspection
DMC-412-A-63-10-00-28A-280A-B /
00241
C 2024-10-28
ALL
Single Boost (or System 1) Hydraulic Drive Quill
(212-040-365-103) - Repair
DMC-412-A-63-10-00-28A-685A-B /
00242
2023-05-31
ALL
Single Boost (or System 1) Hydraulic Drive Quill
(212-040-365-103) - Assembly
DMC-412-A-63-10-00-28A-710A-B /
00243
2023-05-31
ALL
Applicable to: ALL
ECCN EAR99
412-A-63-00-00-00A-00SA-A
28 OCT 2024 Page 13
BHT-412-CRO
Document title
Data module code / Seq number
Issue date
Applicable
to
Rotor Brake Drive Quill (412-040-123-101 and
-103) - Disassembly
DMC-412-A-63-10-00-29A-530A-B /
00244
2023-05-31
ALL
Rotor Brake Drive Quill (412-040-123-101 and
-103) - Cleaning
DMC-412-A-63-10-00-29A-258A-B /
00245
2023-05-31
ALL
Rotor Brake Drive Quill (412-040-123-101 and
-103) - Inspection
DMC-412-A-63-10-00-29A-280A-B /
00246
C 2024-10-28
ALL
Rotor Brake Drive Quill (412-040-123-101 and
-103) - Repair
DMC-412-A-63-10-00-29A-685A-B /
00247
2023-05-31
ALL
Rotor Brake Drive Quill (412-040-123-101 and
-103) - Assembly
DMC-412-A-63-10-00-29A-710A-B /
00248
2023-05-31
ALL
Transmission Mount Friction Damper - General
DMC-412-A-63-10-00-05A-028A-B /
00249
2023-05-31
ALL
Transmission Mount Friction Damper - Inspection DMC-412-A-63-10-00-30A-280A-B /
00250
2023-05-31
ALL
Transmission Mount Friction Damper - Repair
DMC-412-A-63-10-00-30A-685A-B /
00251
2023-05-31
ALL
Transmission Mount Friction Damper - Test
DMC-412-A-63-10-00-30A-322A-B /
00252
2023-05-31
ALL
Transmission Lift Link - Inspection
DMC-412-A-63-10-00-32A-280A-B /
00253
2023-05-31
ALL
Transmission Lift Link - Repair
DMC-412-A-63-10-00-32A-685A-B /
00254
2023-05-31
ALL
Transmission Lift Link Fitting - Maintenance
DMC-412-A-63-10-00-32A-711A-B /
00255
2023-05-31
ALL
Pylon Isolation Mount Bolt - Inspection
DMC-412-A-63-10-00-33A-280A-B /
00256
2023-05-31
ALL
Pylon Isolation Mount Bolt - Repair
DMC-412-A-63-10-00-33A-685A-B /
00257
2023-05-31
ALL
412-A-63-00-00-00A-00SA-A
Page 14 28 OCT 2024
Applicable to: ALL
ECCN EAR99
BHT-412-CRO
Main Driveshaft (212-040-005-103) - Disassembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Extension Bar, 3/4 Drive
Wrench
Wrench Set
L-122
T101306
T101588
1
1
1
Remarks
Procedure
NOTE
SN: 36020-36999 or 37002-37999 or SN: 38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed:
Refer to 412-A-63-10-00-02A-530A-B / 00107.
NOTE
If the main driveshaft is being disassembled for replacement of parts, instead of overhaul, disassemble
only to the extent necessary to replace the parts.
1.
Place the driveshaft in a suitable support.
2.
Remove the retaining ring (1, Figure 1), retainer plate (2), packing (3), and centering spring (4). Discard the packing.
3.
Remove the locking spring (5) from the nut (6).
4.
Insert the wrench (T101306) in the nut (3, Figure 2).
5.
Install the wrench set (T101588) on the outer coupling (8) and install the two washers (6) and the nuts (7).
6.
Insert the extension bar, 3/4 drive (L-122) through the plate of the wrench set (T101588) and engage the wrench
(T101306). Hold the wrench set (T101588) and loosen the nut (3).
7.
Remove the tools.
8.
Remove the nut (6, Figure 1) and the spring retainer (7).
NOTE
The recording of coupling serial numbers to facilitate reassembly is no longer required. It is a
recommended maintenance practice to match the serial numbers of the couplings in order to reassemble
couplings into original position.
9.
Remove the inner coupling (8) and the outer coupling (9), as an assembly, and separate the couplings.
10.
Remove the eight bolts (13), thin aluminum washers (12), boot assembly (11), and packing (10). Discard the packing.
11.
Remove the outer coupling (17) and associated parts in the same manner outlined in Step 1. through Step 10..
Applicable to: ALL
412-A-63-10-00-00A-530A-B
ECCN EAR99
28 OCT 2024 Page 00099-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00001-A-001-01
Figure 1. Main Driveshaft Assembly (212-040-005-103) (Sheet 1 of 1)
412-A-63-10-00-00A-530A-B
Applicable to: ALL
Page 00099-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00002-A-001-01
Figure 2. Wrench (T101306), Wrench Set (T101588), and Extension Bar (L-122) - Tool Application (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-00A-530A-B
ECCN EAR99
28 OCT 2024 Page 00099-3
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-00A-530A-B
Applicable to: ALL
Page 00099-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Main Driveshaft (212-040-005-103) - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Drycleaning solvent
Clean cloth
C-304
C-516
AR
AR
Remarks
Procedure
DO NOT USE drycleaning solvent (C-304) INSIDE ASSEMBLED COUPLING. IF ALL TRACES
OF DRYCLEANING SOLVENT ARE NOT REMOVED FROM PARTS, THE SOLVENT RESIDUE
MAY PREVENT LUBRICANT FROM ADHERING TO PARTS. CONTAMINATION OF BOOTS WITH
DRYCLEANING SOLVENT WILL REQUIRE THE BOOTS TO BE REPLACED.
NOTE
SN: 36020-36999 or 37002-37999 or SN: 38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed:
Refer to 412-A-63-10-00-02A-258A-B / 00108.
1.
Clean the driveshaft parts, except the boots, with drycleaning solvent (C-304).
2.
Dry the parts with dry filtered compressed air.
3.
Clean the boot assemblies (11, Figure 1) with a clean cloth (C-516).
4.
Remove all traces of drycleaning solvent residue from the inner and outer couplings (8 and 9) with a clean cloth
(C-516).
Applicable to: ALL
412-A-63-10-00-00A-258A-B
ECCN EAR99
28 OCT 2024 Page 00100-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00001-A-001-01
Figure 1. Main Driveshaft Assembly (212-040-005-103) (Sheet 1 of 1)
412-A-63-10-00-00A-258A-B
Applicable to: ALL
Page 00100-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Main Driveshaft (212-040-005-103) - Inspection
Procedure
1.
NOTE
SN: 36020-36999 or 37002-37999 or SN: 38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed:
Refer to 412-A-63-10-00-02A-280A-B / 00109.
NOTE
If records or physical appearance of the main driveshaft indicate that the assembly has been subjected
to an accident or incident outside the realm of normal usage, perform a conditional inspection
(412-A-63-10-00-00A-284A-B / 00102). If the driveshaft does not require a conditional inspection,
proceed with the normal inspection (412-A-63-10-00-00A-280B-B / 00103).
Applicable to: ALL
412-A-63-10-00-00A-280A-B
ECCN EAR99
28 OCT 2024 Page 00101-1
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-00A-280A-B
Applicable to: ALL
Page 00101-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Main Driveshaft (212-040-005-103) - Conditional Inspection
Procedure
NOTE
SN: 36020-36999 or 37002-37999 or SN: 38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed:
Refer to 412-A-63-10-00-02A-284A-B / 00110.
1.
Visually inspect the driveshaft for external damage.
2.
Visually inspect the inner and outer couplings for chipped, dented, or cracked teeth or for galling caused by excessive
misalignment. Superficial damage on the coupling teeth is permitted if not detected with a 0.020-inch (0.51-mm)
spherical radius inspection probe. Galling damage and/or evidence of overheating is cause to replace both the
inner and outer couplings on that end of driveshaft.
3.
With the inner and outer couplings (8 and 9, Figure 1) removed from both ends of the shaft, mount the shaft on
centers and check shaft runout. Runout shall not exceed 0.020 inch (0.51 mm) Total Indicated Runout (TIR) at the
mid-point of the shaft or 0.010 inch (0.25 mm) TIR when checked at 7.0 inches (178 mm) from either end.
NOTE
Any evidence of yielding exceeding the limits of Step 3., renders the entire main driveshaft unserviceable
and nonrepairable.
4.
If no evidence of conditions of Step 1. through Step 3. is found, accomplish the normal inspection
(412-A-63-10-00-00A-280B-B / 00103).
Applicable to: ALL
412-A-63-10-00-00A-284A-B
ECCN EAR99
28 OCT 2024 Page 00102-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00001-A-001-01
Figure 1. Main Driveshaft Assembly (212-040-005-103) (Sheet 1 of 1)
412-A-63-10-00-00A-284A-B
Applicable to: ALL
Page 00102-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Main Driveshaft (212-040-005-103) - Normal Inspection
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
India stone
C-464
AR
Remarks
Procedure
NOTE
SN: 36020-36999 or 37002-37999 or SN: 38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed:
Refer to 412-A-63-10-00-02A-280B-B / 00111.
1.
Inspect the driveshaft (16, Figure 1) in accordance with Figure 2.
2.
Inspect the outer couplings (9 and 17, Figure 1) in accordance with Figure 3.
3.
Inspect the inner coupling (8, Figure 1) and the similar coupling at the opposite end of the driveshaft in accordance
with Figure 4.
4.
Inspect the nut (6, Figure 1) and the similar nut at the opposite end of the driveshaft in accordance with Figure 2.
NOTE
It is recommended that the boot assembly (11, Figure 1) be replaced each 1200 hours of operation.
5.
Inspect the boot assembly (11) and the similar boot assembly at the opposite end of the driveshaft for cracks, tears,
wrinkles, and bands of heavy wear against the shroud. No defects are permitted.
6.
Inspect the packing groove on the retainer plate (2) and the surface in the outer couplings (9 and 17) contacted by the
packing for nicks or burrs. Remove any such defects with a fine india stone (C-464). Carefully remove any foreign
material. If nicks deep enough to permit passage of grease are found, replace the defective part. Inspect the area
that contacts the retaining ring (1) for excessive wear.
7.
Inspect the locking spring (5) and the similar spring at the opposite end of the driveshaft for deformation. Any
damage that can be detected visually is not permitted.
8.
Inspect the centering spring (4) and the similar spring at the opposite end of the driveshaft for deformation. Any
damage that can be detected visually is not permitted.
9.
Inspect the retaining ring (1) and the similar retaining ring at the opposite end of the driveshaft for deformation. Any
damage that can be detected visually is not permitted.
10.
Inspect the spring retainer (7) for corrosion damage. Pits to a maximum depth of 0.010 inch (0.25 mm) are permitted.
Chemically remove corrosion products. Do not polish out.
NOTE
The following procedure is to be accomplished in conjunction with the 2500-hour or 3000-hour overhaul
and conditional inspection. This procedure is not required if the driveshaft is disassembled for lubrication
only.
11.
Inspect the retainer plate (2), centering spring (4), and spring retainer (7) with the fluorescent penetrant method
(BHT-ALL-SPM, Standard Practices Manual).
12.
Inspect the following parts by magnetic particle inspection. Demagnetize the parts after the magnetic particle
inspection. Refer to Table 2 and the BHT-ALL-SPM, Standard Practices Manual for the procedure.
Figure 1INDEX NO.
NOMENCLATURE
CODE
6
Nut
M
8
Inner Coupling
M
9
Outer Coupling
M
16
Driveshaft
M
Applicable to: ALL
412-A-63-10-00-00A-280B-B
ECCN EAR99
28 OCT 2024 Page 00103-1
BHT-412-CRO
Table 2. Magnetic Particle Inspection
PART NUMBER
NOMENCLATURE
ITEM AND FIGURE
SET UP AND MAGNETIZATION CURRENT REQUIREMENTS
MAIN DRIVESHAFT ASSEMBLY (212-040-005-103)
204-040-184-001
Nut
6, Figure 1
SET UP:
Place part over a 1.5-inch diameter central conductor.
Current for primary diameters, magnetize at 1990 amps.
Omit coil shot.
212-040-687-001
Inner Coupling
8, Figure 1
SET UP:
Place part over a 2-inch diameter central conductor.
Current for primary diameters, magnetize at 2820 amps.
Optional current for secondary diameters, magnetize at 1420 amps.
Omit coil shot.
212-040-688-003
Outer Coupling
9, Figure 1
SET UP:
Place part over a 2-inch diameter central conductor.
Current for primary diameters, magnetize at 2590 amps.
Large I.D. of part: Magnetize at three approximately equally spaced radial locations on central conductor.
SET UP: 5 TURN COIL SHOT:
Disc-shaped portion of part: Place part in bottom of coil.
Magnetize at 3000 amps.
Rotate part 1/4 turn and repeat.
212-040-686-001
Driveshaft
16, Figure 1
SET UP:
Place part over a 2-inch diameter central conductor.
Current for primary diameters, magnetize at 2000 amps.
SET UP: 5 TURN COIL SHOT:
With part supported on the conducting rod between the contact plates, magnetize at 2400 amps.
NOTES:
1. Magnetization currents provided are applicable to magnetic particle inspection apparatus using Direct Current (DC) . If an
Alternating Current (AC) apparatus is used, adjust the current as follows: AC= 0.667 x DC.
2. Ferrous parts requiring magnetic particle inspection that are not addressed in the attached material, are to be inspected in
accordance with the general procedures outlined in ASTM E1444 standard practices (BHT-ALL-SPM, Chapter 6, Standard
Practices Manual).
3. Part numbers listed apply to all successive dash numbers for that component unless otherwise specified.
412-A-63-10-00-00A-280B-B
Applicable to: ALL
Page 00103-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00001-A-001-01
Figure 1. Main Driveshaft Assembly (212-040-005-103) (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-00A-280B-B
ECCN EAR99
28 OCT 2024 Page 00103-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00003-A-001-01
Figure 2. Main Driveshaft (212-040-686-001) and Nut (204-040-184-001) - Damage Limits (Sheet 1 of 2)
412-A-63-10-00-00A-280B-B
Applicable to: ALL
Page 00103-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00004-A-001-01
Figure 2. Main Driveshaft (212-040-686-001) and Nut (204-040-184-001) - Damage Limits (Sheet 2 of 2)
Applicable to: ALL
412-A-63-10-00-00A-280B-B
ECCN EAR99
28 OCT 2024 Page 00103-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00005-A-001-01
Figure 3. Main Driveshaft Outer Coupling (212-040-005-103) - Damage Limits (Sheet 1 of 4)
412-A-63-10-00-00A-280B-B
Applicable to: ALL
Page 00103-6 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00006-A-001-01
Figure 3. Main Driveshaft Outer Coupling (212-040-005-103) - Damage Limits (Sheet 2 of 4)
Applicable to: ALL
412-A-63-10-00-00A-280B-B
ECCN EAR99
28 OCT 2024 Page 00103-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00007-A-001-01
Figure 3. Main Driveshaft Outer Coupling (212-040-005-103) - Damage Limits (Sheet 3 of 4)
412-A-63-10-00-00A-280B-B
Applicable to: ALL
Page 00103-8 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00008-A-001-01
Figure 3. Main Driveshaft Outer Coupling (212-040-005-103) - Damage Limits (Sheet 4 of 4)
Applicable to: ALL
412-A-63-10-00-00A-280B-B
ECCN EAR99
28 OCT 2024 Page 00103-9
BHT-412-CRO
ICN-412-A-631000-B-97499-00009-A-001-01
Figure 4. Main Driveshaft Inner Coupling (212-040-005-103) - Damage Limits (Sheet 1 of 3)
412-A-63-10-00-00A-280B-B
Applicable to: ALL
Page 00103-10 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00010-A-001-01
Figure 4. Main Driveshaft Inner Coupling (212-040-005-103) - Damage Limits (Sheet 2 of 3)
Applicable to: ALL
412-A-63-10-00-00A-280B-B
ECCN EAR99
28 OCT 2024 Page 00103-11
BHT-412-CRO
ICN-412-A-631000-B-97499-00011-A-001-01
Figure 4. Main Driveshaft Inner Coupling (212-040-005-103) - Damage Limits (Sheet 3 of 3)
412-A-63-10-00-00A-280B-B
Applicable to: ALL
Page 00103-12 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Main Driveshaft (212-040-005-103) - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Cadmium plating solution
Epoxy/zinc coating
Drycleaning solvent
MEK
Cleaning compound
Abrasive cloth or paper
Abrasive pad
Masking tape
India stone
Clean cloth
C-108
C-208
C-304
C-309
C-318
C-406
C-407
C-426
C-464
C-516
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
Remarks
Procedure
NOTE
SN: 36020-36999 or 37002-37999 or SN: 38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed:
Refer to 412-A-63-10-00-02A-685A-B / 00112.
1.
Replace all the parts that fail the magnetic particle inspection.
2.
Replace all the parts that have damaged threads.
3.
Replace the inner and outer couplings (8 and 9, Figure 1) if evidence of overheating is found.
NOTE
It is recommended that the boot assembly (11) be replaced each 1200 hours of operation.
4.
Replace the boot assembly (11) if cracked, torn, wrinkled, or excessive wear with the shroud is noted.
5.
Dress off burrs on the retainer plate (2) with abrasive cloth or paper (C-406) to ensure proper packing seat.
6.
Replace the retaining ring (1), spring retainer (7), centering spring (4), and locking spring (5) if damaged, deformed, or
corrosion pitting is beyond the permitted limits.
7.
Replace the parts the exceed the wear limits of Figure 2, Figure 3, and Figure 4.
8.
With abrasive cloth or paper (C-406), polish out mechanical and corrosion damage on the driveshaft (16, Figure 1)
that is within the limits shown in Figure 2. Blend the repaired area to a minimum radius of 0.50 inch (12.7 mm). The
finished repair must be 32 RHR or better (BHT-ALL-SPM, Standard Practices Manual).
DO NOT ALLOW CADMIUM PLATING SOLUTION TO CONTACT ANY SPLINE TOOTH SURFACE.
DO NOT APPLY ANY SUPPLEMENTARY CHROMATE TREATMENT.
9.
Touch up repair areas with cadmium plating solution (C-108). Use only the brush cadmium plating procedure
defined in the BHT-ALL-SPM, Standard Practices Manual.
10.
Polish out very small nicks and dents on the driveshaft spline teeth with a fine india stone (C-464).
11.
Replace missing or illegible nameplates (14 or 15, Figure 1). Refer to the BHT-ALL-SPM, Standard Practices
Manual for nameplate bonding instructions.
11.1.
Stamp the required information on a new nameplate. Bond the nameplate to the driveshaft.
Applicable to: ALL
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11.2.
Bond the unmarked name plate, face down, to the driveshaft, 180° apart from the marked nameplate for balance
purposes.
12.
Polish out very small nicks and dents on the spline teeth of the outer couplings with a fine india stone (C-464).
13.
Polish out very small nicks and dents on the spline teeth of the inner couplings with a fine india stone (C-464).
14.
Paint the inside of the driveshaft (Figure 5, View A) only if the existing finish has been damaged. Comply with
the following:
14.1.
Clean the inside of the driveshaft with drycleaning solvent (C-304).
14.2.
Allow solvent to dry.
14.3.
Prepare epoxy/zinc coating (C-208) as follows:
NOTE
The epoxy/zinc coating material is supplied in a three-component kit.
14.3.1.
Measure an adequate volume of base material to paint the number of driveshafts that can be painted in 8 hours or less.
14.3.2.
Add an equal volume of the accelerator/ thinner and mix thoroughly.
14.3.3.
Weigh the mixed material.
14.3.4.
Calculate the required amount of zinc powder to produce 20 to 25% (weight) of the mixed material. For instance,
each 100 grams of base/ thinner mixture requires 20 to 25 grams of zinc powder.
14.3.5.
Weigh out the required amount of zinc powder and add to the base/thinner mixture with constant stirring to achieve
a uniform mixture.
14.3.6.
Allow the mixed material to set for a minimum of 1 hour at room temperature prior to use. Discard the mixed material
if not used within 8 hours after mixing.
14.4.
Mask off areas of the driveshaft outside Area A with masking tape (C-426) (Figure 5).
14.5.
Apply one coat of epoxy/zinc coating (C-208) to Area A (Figure 5). Seal or plug one end of the driveshaft. Flow
epoxy/zinc mixture into the hollow driveshaft while you turn the driveshaft. Make sure to fully coat the entire inside
surface. Drain excess coating material from the driveshaft.
NOTE
The material drained from the driveshaft into a clean container may be used on other parts if the 8-hour
pot life is not exceeded.
14.6.
Keep the driveshaft vertical for 1 hour after coating to prevent coating from puddling on one side.
14.7.
The coating will reach final cure in 72 hours at ambient temperature.
14.8.
The coating may be heat cured as follows:
14.8.1.
Dry at ambient conditions for 2 hours.
14.8.2.
Cure at 150 to 160°F (66 to 71°C) for a minimum of 1 hour.
14.9.
Remove the masking tape.
14.10.
Touch up small areas that may have been inadvertently missed during initial application.
14.11.
The coating, after drying, must be free of pits, mud cracking, craters, blisters, and other surface irregularities. The
metallic filler must be evenly dispersed to present a relatively uniform gray appearance. Some dark streaks in
coatings applied by the fill and drain process caused by heavier zinc concentration are permitted.
15.
Replace the visual over temperature indicator (TEMP-PLATES) on the coupling (Figure 3) if mutilated or discolored,
as follows:
15.1.
Remove damaged TEMP-PLATES with MEK (C-309) and a clean cloth (C-516). Wipe dry with a clean cloth (C-516)
before MEK evaporates.
412-A-63-10-00-00A-685A-B
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BONDING SURFACE AND TEMP-PLATES MUST BE FREE OF ALL CONTAMINATION. ANY
CONTAMINATION COULD ALLOW THE TEMP-PLATES TO COME OFF OR INDICATE FALSE
TEMPERATURES.
15.2.
Prepare the coupling surface for bonding by scrubbing the area with a clean cloth (C-516) moistened with MEK
(C-309). Wipe dry before MEK evaporates. The surface should be at least 0.050 inch (1.27 mm) larger than the
TEMP-PLATE.
15.3.
Accomplish a water break free test on the prepared bonding surface by applying distilled or demineralized water from
a suitable dispenser (squeeze bottle). The water must flow into a continuous film without gathering into distinct water
droplets within 25 seconds after application. Wipe dry with a clean cloth (C-516). If the coupling bonding surface
does not meet the water break free test and you have ensured the cleaning materials are not contaminated, clean
the coupling bonding surfaces as follows:
NOTE
Follow the manufacturer’s recommendations for proper water mixtures.
15.3.1.
Scrub the coupling bonding surface with a clean cloth (C-516) and cleaning compound (C-318). Follow the cleaning
with a thorough water rinse.
15.3.2.
Thoroughly dry the coupling surface and repeat the water break free test as stated in Step 15.3..
16.
Install the TEMP-PLATES as follows:
IN ORDER TO PREVENT CONTAMINATION OF TEMP-PLATE ADHESIVE BACK, MAKE SURE HANDS
ARE THOROUGHLY CLEANED BEFORE WORKING WITH TEMP-PLATES. DO NOT PRESS OR RUB
THE TEMP-PLATE WITH BARE FINGERS DURING INSTALLATION ON COUPLING AS THIS WILL
CONTAMINATE SURFACE.
16.1.
Remove the protective backing from the TEMP-PLATE and carefully position onto the prepared surface.
16.2.
With a clean cloth (C-516), work the TEMP-PLATES into the contour of the coupling. Make sure the TEMP-PLATES
are in full contact with the coupling surface.
NOTE
Apply epoxy coating to the TEMP-PLATES immediately following the installation of the TEMP-PLATES
on each coupling.
17.
Install epoxy coating over the TEMP-PLATES as follows:
THE USE OF ANY EPOXY ADHESIVE OTHER THAN SPECIFIED IS NOT AUTHORIZED.
17.1.
Mix epoxy coating per manufacturer recommendations.
17.2.
With a soft bristled brush (artist brush), vigorously mix the epoxy. A few drops of recommended thinner may be added
during mixing to reduce the viscosity to a level that permits uniform brush application of the mixture and will not run
when applied to a vertical surface. The final viscosity of the mixture should be similar to a heavy bodied paint.
TOO THIN OF AN EPOXY COATING MAY SEEP INTO TEMP-PLATE CAUSING INDICATOR DOTS TO
TURN BLACK, IN WHICH EVENT, TEMP-PLATE MUST BE REPLACED.
17.3.
Uniformly apply epoxy coating over the TEMP-PLATE to a thickness of approximately 0.002 to 0.004 inch (0.05 to
0.10 mm). The coating should totally cover the surface of TEMP-PLATE and extend approximately 0.250 inch (6.35
mm) beyond the edges of the TEMP-PLATE.
18.
Cure the epoxy coating as follows:
Applicable to: ALL
412-A-63-10-00-00A-685A-B
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BHT-412-CRO
DO NOT EXPOSE EPOXY COATING TO OIL, GREASE, CLEANING SOLVENTS, OR OTHER
CHEMICALS DURING CURE.
18.1.
Allow the epoxy coating to cure at room temperature (60 to 100°F (16 to 38°C)) for a minimum of 6 hours prior to
helicopter operation. For best results, allow to cure overnight.
18.2.
The epoxy coating total curing time can be accelerated by allowing the epoxy coating to cure at room temperature for
1 hour, then place the coupling in a temperature controlled oven for 1 to 2 hours at a temperature of 150 to 180°F (66
to 82°C). An alternate source of heat can be used if the temperature does not exceed 180°F (82°C).
NOTE
Following the cure, the TEMP-PLATE should conform to the contour of the coupling and be free of lifted
edges. Indicating dots on the TEMP-PLATE must remain the original white or light gray with no or partial
black discoloration. Some lifting at the extreme ends of TEMP-PLATES installed on grooved couplings
is permitted (Figure 3, View A). Lifting is permitted only at the bottom, as shown, and should not exceed
0.030 inch (0.76 mm).
18.3.
After curing time, accomplish an adhesion test by pressing a 1.0-inch (25-mm) wide strip of high adhesion tape over
each TEMP-PLATE and beyond the edge of the epoxy overcoat. Grasp one end of the tape and remove the tape in
one abrupt motion. Lifting or peeling of the epoxy coating or TEMP-PLATE is not permitted and requires replacement
of the TEMP-PLATE. Repeat Step 15. through Step 18..
19.
Treat repaired cadmium plated surfaces with cadmium plating solution (C-108). Refer to the BHT-ALL-SPM, Standard
Practices Manual for procedures.
412-A-63-10-00-00A-685A-B
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Page 00104-4 28 OCT 2024
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ICN-412-A-631000-B-97499-00001-A-001-01
Figure 1. Main Driveshaft Assembly (212-040-005-103) (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-00A-685A-B
ECCN EAR99
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ICN-412-A-631000-B-97499-00003-A-001-01
Figure 2. Main Driveshaft (212-040-686-001) and Nut (204-040-184-001) - Damage Limits (Sheet 1 of 2)
412-A-63-10-00-00A-685A-B
Applicable to: ALL
Page 00104-6 28 OCT 2024
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ICN-412-A-631000-B-97499-00004-A-001-01
Figure 2. Main Driveshaft (212-040-686-001) and Nut (204-040-184-001) - Damage Limits (Sheet 2 of 2)
Applicable to: ALL
412-A-63-10-00-00A-685A-B
ECCN EAR99
28 OCT 2024 Page 00104-7
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ICN-412-A-631000-B-97499-00005-A-001-01
Figure 3. Main Driveshaft Outer Coupling (212-040-005-103) - Damage Limits (Sheet 1 of 4)
412-A-63-10-00-00A-685A-B
Applicable to: ALL
Page 00104-8 28 OCT 2024
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ICN-412-A-631000-B-97499-00006-A-001-01
Figure 3. Main Driveshaft Outer Coupling (212-040-005-103) - Damage Limits (Sheet 2 of 4)
Applicable to: ALL
412-A-63-10-00-00A-685A-B
ECCN EAR99
28 OCT 2024 Page 00104-9
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ICN-412-A-631000-B-97499-00007-A-001-01
Figure 3. Main Driveshaft Outer Coupling (212-040-005-103) - Damage Limits (Sheet 3 of 4)
412-A-63-10-00-00A-685A-B
Applicable to: ALL
Page 00104-10 28 OCT 2024
ECCN EAR99
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ICN-412-A-631000-B-97499-00008-A-001-01
Figure 3. Main Driveshaft Outer Coupling (212-040-005-103) - Damage Limits (Sheet 4 of 4)
Applicable to: ALL
412-A-63-10-00-00A-685A-B
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28 OCT 2024 Page 00104-11
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ICN-412-A-631000-B-97499-00009-A-001-01
Figure 4. Main Driveshaft Inner Coupling (212-040-005-103) - Damage Limits (Sheet 1 of 3)
412-A-63-10-00-00A-685A-B
Applicable to: ALL
Page 00104-12 28 OCT 2024
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ICN-412-A-631000-B-97499-00010-A-001-01
Figure 4. Main Driveshaft Inner Coupling (212-040-005-103) - Damage Limits (Sheet 2 of 3)
Applicable to: ALL
412-A-63-10-00-00A-685A-B
ECCN EAR99
28 OCT 2024 Page 00104-13
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ICN-412-A-631000-B-97499-00011-A-001-01
Figure 4. Main Driveshaft Inner Coupling (212-040-005-103) - Damage Limits (Sheet 3 of 3)
412-A-63-10-00-00A-685A-B
Applicable to: ALL
Page 00104-14 28 OCT 2024
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ICN-412-A-631000-B-97499-00050-A-001-01
Figure 5. Main Driveshaft (212-040-005-103) - Paint Area (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-00A-685A-B
ECCN EAR99
28 OCT 2024 Page 00104-15
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-00A-685A-B
Applicable to: ALL
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Main Driveshaft (212-040-005-103) - Lubrication
Procedure
NOTE
SN: 36020-36999 or 37002-37999 or SN: 38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed:
Refer to 412-A-63-10-00-02A-240A-B / 00113.
1.
The inspection of driveshaft couplings and the internal inspection of the driveshaft for corrosion is required
when the driveshaft is lubricated at the interval designated in the BHT-412-MM, Chapter 5. Refer to
412-A-63-10-00-00A-530A-B / 00099, 412-A-63-10-00-00A-258A-B / 00100, 412-A-63-10-00-00A-280A-B / 00101,
412-A-63-10-00-00A-240A-B / 00105, and 412-A-63-10-00-00A-710A-B / 00106 for instructions to disassemble,
clean, inspect, lubricate, and assemble the driveshaft.
Applicable to: ALL
412-A-63-10-00-00A-240A-B
ECCN EAR99
28 OCT 2024 Page 00105-1
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Intentionally blank page
412-A-63-10-00-00A-240A-B
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Page 00105-2 28 OCT 2024
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BHT-412-CRO
Main Driveshaft (212-040-005-103) - Assembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Extension Bar, 3/4 Drive
Splined Wrench
Wrench Set
L-122
T101306
T101588
1
1
1
Remarks
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Lubricant
Lockwire
C-015
C-405
AR
AR
Remarks
Procedure
NOTE
SN: 36020-36999 or 37002-37999 or SN: 38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed:
Refer to 412-A-63-10-00-02A-710A-B / 00114.
1.
Lubricate a new packing (10, Figure 1) with lubricant (C-015) and install in the groove in the boot assembly (11).
NOTE
The recording of coupling serial numbers to facilitate reassembly is no longer required. It is a desirable
maintenance practice to match the serial numbers of the couplings in order to reassemble couplings into
original position.
2.
Select the outer coupling (9) and inner coupling (8) that are to be assembled.
3.
Position the outer coupling (9) on the boot assembly (11). Install the eight bolts (13) and the washers (12). Torque the
bolts 50 to 70 inch-pounds (5.65 to 7.91 Nm). Secure the bolt heads together with lockwire (C-405). Position the
coupling with the boot assembly down on the work bench.
4.
Squeeze 1/2 tube of lubricant (C-015) into the boot assembly (11) and the outer coupling (9). Hand pack the lubricant
evenly over the coupling and behind the dam in the boot, as shown in View A.
5.
Put the inner coupling (8) into the outer coupling (9). Make sure that the inner coupling is installed into the lip of
the boot assembly (11).
6.
Lightly coat the spring retainer (7), locking spring (5), centering spring (4), nut (6), and the threads and splines of
the driveshaft (16) with lubricant (C-015).
7.
Place the driveshaft (16) in a suitable support. Install the inner and outer couplings (8 and 9) on the driveshaft.
8.
Position the spring retainer (7) in the driveshaft (16). Install the nut (6) finger tight.
9.
Position the splined wrench (T101306) (2, Figure 2) in the nut (3).
10.
Position the wrench set (T101588) (5) on the outer coupling (8).
THE TEETH OF INNER COUPLING (4) SHALL FULLY ENGAGE SPLINES OF OUTER COUPLING (8)
BEFORE NUT (3) IS TORQUED.
11.
Insert the extension bar, 3/4 drive (L-122) through the wrench set (T101588) (5) and engage the splined wrench
(T101306) (2). Torque the nut (3) 100 to 200 foot-pounds (136 to 271 Nm).
12.
Remove the tools.
Applicable to: ALL
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28 OCT 2024 Page 00106-1
BHT-412-CRO
13.
Install the locking spring (5, Figure 1). Make sure that the tang of the locking spring is fully engaged in the hole in
the nut (6) and the slot in the driveshaft (16). Check the boot assembly (11) for wrinkles. If wrinkles are found,
loosen and retorque the nut.
14.
Squeeze one tube of lubricant (C-015) into the outer coupling (9). Spread the lubricant evenly over the splines of the
outer coupling. Install the centering spring (4) on the spring retainer (7).
15.
Lightly coat the new packing (3) with lubricant (C-015).
16.
Install the packing (3) on the retainer plate (2) and install into the outer coupling (9).
NOTE
After the installation of the new packing (3), check that no rubber slivers are present indicating the packing
was damaged during installation.
17.
Install the retaining ring (1) in the groove of the outer coupling (9). Inspect the ring for proper seating in the groove.
18.
Install the outer coupling (17) and associated parts in the same manner outlined in Step 1. through Step 17..
19.
Inspect the boot assembly (11) for damage that may have occurred during assembly. Wrinkles are caused by
misindexing coupling teeth. Tears are usually caused during torquing of the nut (6).
412-A-63-10-00-00A-710A-B
Applicable to: ALL
Page 00106-2 28 OCT 2024
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ICN-412-A-631000-B-97499-00001-A-001-01
Figure 1. Main Driveshaft Assembly (212-040-005-103) (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-00A-710A-B
ECCN EAR99
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ICN-412-A-631000-B-97499-00002-A-001-01
Figure 2. Wrench (T101306), Wrench Set (T101588), and Extension Bar (L-122) - Tool Application (Sheet 1 of 1)
412-A-63-10-00-00A-710A-B
Applicable to: ALL
Page 00106-4 28 OCT 2024
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Main Driveshaft (412-040-005-101 and -103) - Disassembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Remarks
Extension Bar, 3/4 Drive
L-122
1
The extension bar (L-122) is part of the wrench
set (T103063).
Wrench
Wrench Set
T101306
T103063
1
1
Procedure
NOTE
If the engine-to-transmission driveshaft is being disassembled for replacement of parts, instead of
overhaul, disassemble only to the extent necessary to replace the parts.
To maximize the service life of the driveshaft couplings and to aid in the diagnoses of driveshaft problems,
it is recommended the couplings be reinstalled with their original mates at their original ends (transmission
end or engine end) of the driveshaft. To maximize coupling gear and propagation of any driveshaft
coupling tooth damage, it is also recommended the inner and outer couplings be installed such that the
teeth of one coupling are in contact with the same teeth of the mating coupling. To meet these objectives,
suitable non-permanent markings should be applied to the driveshaft couplings during the disassembly
process.
1.
Place the driveshaft in a suitable support.
2.
Remove the retaining ring (1, Figure 1), packing (3), retainer plate (2), and centering spring (4). Discard the packing.
3.
Remove the locking spring (5) from the nut (6).
4.
Position the wrench (T101306) (2, Figure 2) in the nut (3).
5.
Position the wrench set (T103063) (5) on the outer coupling (8) and install two steel washers (6) and the nuts (7).
6.
Insert the extension bar, 3/4 drive (L-122) through the plate of the wrench set (T103063) and engage the wrench
(T101306) (2). Hold the wrench set (T103063) and loosen the nut (3).
7.
Remove the tools.
8.
Remove the nut (6, Figure 1) and the spring retainer (7).
9.
Remove the inner coupling (8) and the outer coupling (9) as an assembly, and separate the couplings.
10.
Remove the six bolts (14), washers (13), nuts (12), boot assembly (11), and packing (10). Discard the packing.
11.
Remove the outer coupling (17) and associated parts in the same manner outlined in Step 1. through Step 10..
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
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28 OCT 2024 Page 00107-1
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ICN-412-A-631000-B-97499-00040-A-001-01
Figure 1. Main Driveshaft Assembly (412-040-005-101 and -103) (Sheet 1 of 1)
412-A-63-10-00-02A-530A-B
Page 00107-2 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00051-A-001-01
Figure 2. Wrench (T101306) - Tool Application (Sheet 1 of 1)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
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Page 00107-4 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Main Driveshaft (412-040-005-101 and -103) - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Drycleaning solvent
Clean cloth
C-304
C-516
AR
AR
Remarks
Procedure
DO NOT USE drycleaning solvent (C-304) INSIDE ASSEMBLED COUPLING. IF ALL TRACES OF
SOLVENT ARE NOT REMOVED FROM PARTS, THE DRYCLEANING SOLVENT RESIDUE MAY
PREVENT LUBRICANT FROM ADHERING TO PARTS.
1.
Clean the driveshaft parts except the boots with drycleaning solvent (C-304).
2.
Dry the parts with dry, filtered compressed air.
3.
Clean the boot assembly (11, Figure 1) with a clean cloth (C-516).
4.
Remove all traces of solvent residue from the inner and outer couplings (8 and 9) with a clean cloth (C-516).
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
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28 OCT 2024 Page 00108-1
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ICN-412-A-631000-B-97499-00040-A-001-01
Figure 1. Main Driveshaft Assembly (412-040-005-101 and -103) (Sheet 1 of 1)
412-A-63-10-00-02A-258A-B
Page 00108-2 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Main Driveshaft (412-040-005-101 and -103) - Inspection
Procedure
1.
NOTE
If records or the physical appearance of the main driveshaft indicate that the assembly has been
subjected to an accident or incident outside the realm of normal usage, perform the conditional inspection
(412-A-63-10-00-02A-284A-B / 00110). If the driveshaft does not require a conditional inspection,
proceed with the normal inspection (412-A-63-10-00-02A-280B-B / 00111).
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
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412-A-63-10-00-02A-280A-B
Page 00109-2 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Main Driveshaft (412-040-005-101 and -103) - Conditional Inspection
Procedure
1.
Visually inspect the driveshaft for external damage.
2.
Visually inspect the inner and outer couplings for chipped, dented, or cracked teeth and for scoring of the teeth
caused by excessive misalignment. Refer to Figure 1 and Figure 2 for the coupling damage limits.
NOTE
Any evidence of yielding, or exceeding the following limits, renders the entire main driveshaft
unserviceable and nonrepairable.
3.
With the inner and outer couplings (8 and 9, Figure 3) removed from both ends of the shaft, mount the shaft on the
centers and check shaft runout. Runout shall not exceed 0.020 inch (0.51 mm) Total Indicated Runout (TIR) at the
mid-point of the shaft or 0.010 inch (0.25 mm) TIR when checked at 7.0 inches (178 mm) from either end.
4.
If no evidence of the conditions of Step 1. through Step 3. is found, accomplish the normal inspection
(412-A-63-10-00-02A-280B-B / 00111).
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-02A-284A-B
28 OCT 2024 Page 00110-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00052-A-001-01
Figure 1. Main Driveshaft Outer Coupling (214-040-659-005) - Damage Limits (Sheet 1 of 4)
412-A-63-10-00-02A-284A-B
Page 00110-2 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00053-A-001-01
Figure 1. Main Driveshaft Outer Coupling (214-040-659-005) - Damage Limits (Sheet 2 of 4)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-02A-284A-B
28 OCT 2024 Page 00110-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00054-A-001-01
Figure 1. Main Driveshaft Outer Coupling (214-040-659-005) - Damage Limits (Sheet 3 of 4)
412-A-63-10-00-02A-284A-B
Page 00110-4 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00055-A-001-01
Figure 1. Main Driveshaft Outer Coupling (214-040-659-005) - Damage Limits (Sheet 4 of 4)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-02A-284A-B
28 OCT 2024 Page 00110-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00056-A-001-01
Figure 2. Main Driveshaft Inner Coupling (214-040-657-003) - Damage Limits (Sheet 1 of 4)
412-A-63-10-00-02A-284A-B
Page 00110-6 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00057-A-001-01
Figure 2. Main Driveshaft Inner Coupling (214-040-657-003) - Damage Limits (Sheet 2 of 4)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-02A-284A-B
28 OCT 2024 Page 00110-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00058-A-001-01
Figure 2. Main Driveshaft Inner Coupling (214-040-657-003) - Damage Limits (Sheet 3 of 4)
412-A-63-10-00-02A-284A-B
Page 00110-8 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00059-A-001-01
Figure 2. Main Driveshaft Inner Coupling (214-040-657-003) - Damage Limits (Sheet 4 of 4)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-02A-284A-B
28 OCT 2024 Page 00110-9
BHT-412-CRO
ICN-412-A-631000-B-97499-00040-A-001-01
Figure 3. Main Driveshaft Assembly (412-040-005-101 and -103) (Sheet 1 of 1)
412-A-63-10-00-02A-284A-B
Page 00110-10 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Main Driveshaft (412-040-005-101 and -103) - Normal Inspection
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
India stone
C-464
AR
Remarks
Procedure
NOTE
Overtemperature indicator dots on the temperature indicator TEMP-PLATES are of a white or light gray
color and turn black when exposed to an overtemperature condition. Chemical contamination can also
cause indicating dots to turn black.
1.
Inspect the outer couplings (9 and 17, Figure 1) TEMP-PLATES for evidence of overtemperature indication. If
overtemperature indication is noted, perform the coupling overtemperature inspection as follows:
1.1.
Inspect the outer coupling cadmium plating for discoloration (circumferential). If a tan or light brown band or blistering
is found, replace the outer and inner coupling.
1.2.
Inspect the gear teeth of the outer coupling and inner couplings for discoloration (brown or blue) in normal bright
contact patterns. If discoloration is found, replace the outer and inner couplings.
1.3.
Inspect the outer coupling and inner coupling under a 5X to 10X magnifying glass for teeth exhibiting signs of metal
smearing or tearing in contact patterns. If smearing or tearing is found, replace the outer and inner couplings
(Figure 2).
1.4.
Inspect the grease from the outer and inner couplings. If the grease is very viscous (thick) and has a strong pungent
odor, replace the outer and inner couplings.
NOTE
If the TEMP-PLATES are to be replaced, replace the TEMP-PLATES after completing the entire inspection
procedure and the couplings have been determined serviceable.
2.
Inspect the outer couplings TEMP-PLATES (Figure 2) for deterioration, debonding, or discoloration. Replace the
TEMP-PLATES in accordance with the procedures in 412-A-63-10-00-02A-685A-B / 00112.
3.
Inspect the driveshaft (16, Figure 1) for damage limits in accordance with Figure 3.
4.
Inspect the outer couplings (9 and 17, Figure 1) for damage limits in accordance with Figure 2.
5.
Inspect the inner coupling (8, Figure 1) and the similar coupling at the opposite end of the driveshaft for damage
limits in accordance with Figure 4.
6.
Inspect the nut (6, Figure 1) and the similar nut at the opposite end of the driveshaft for damage limits in accordance
with Figure 3.
7.
Inspect the boot assembly (11, Figure 1) and the similar boot at the opposite end of the driveshaft as follows:
7.1.
Inspect the boot assembly (11) and the similar boot at the opposite end of the driveshaft for cracks in the metallic
components and cracks, tears, wrinkles, and evidence of chemical damage in the elastomeric portion of the boot.
Defects of this type are not permitted.
7.2.
Visually inspect the outer surface of the elastomeric portion of the boot for areas (bands) of wear caused by contact
with the conical boot retainer in the presence of abrasive material. Damage of this type having the appearance of
depth or thinning of the boot is not permitted.
7.3.
Support the outer ring of the boot on the blocks and slowly displace the inner ring axially, by hand, to upper and
lower limits of travel. Replace the boot if the elastomeric portion does not roll smoothly or exhibits permanent flats,
wrinkles, or any other major deformities as it flexes.
8.
Inspect the retainer plate (2) as follows:
8.1.
Inspect the packing groove in the retainer plate (2) and the surface in the outer couplings (9 and 17) contacted
by the packing for nick or burrs.
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-02A-280B-B
28 OCT 2024 Page 00111-1
BHT-412-CRO
8.2.
Remove any nicks or burrs with an india stone (C-464). Carefully remove any foreign material.
8.3.
If nicks deep enough to permit passage of grease are found, replace the defective part.
8.4.
Inspect the area that contacts the retaining ring (1) for excessive wear.
9.
Inspect the locking spring (5) and the similar spring at the opposite end of the driveshaft for deformation. Any
damage that can be detected visually, is not permitted.
10.
Inspect the centering spring (4) and the similar spring at the opposite end of the driveshaft for deformation. Any
damage that can be detected visually, is not permitted.
11.
Inspect the retaining ring (1) and the similar retaining ring at the opposite end of the driveshaft for deformation. Any
damage that can be detected visually, is not permitted.
12.
Inspect the spring retainer (7) for corrosion damage. Pits to a maximum depth of 0.010 inch (0.25 mm) are permitted.
Remove corrosion products with a wire brush.
NOTE
The following procedure is to be done in conjunction with an overhaul and conditional inspection. This
procedure is not required if disassembly is for relubrication only.
13.
Inspect the retainer plate (2), centering spring (4), and spring retainer (7) with the fluorescent penetrant method
(BHT-ALL-SPM, Standard Practices Manual).
14.
Inspect the following parts by magnetic particle inspection. Demagnetize the parts after the magnetic particle
inspection. Refer to Table 2 and the BHT-ALL-SPM, Standard Practices Manual for the procedure.
Figure 1INDEX NUMBER
NOMENCLATURE
6
Nut
8
Inner Coupling
9
Outer Coupling
16
Driveshaft
Table 2. Magnetic Particle Inspection
PART NUMBER
NOMENCLATURE
ITEM AND FIGURE
SET UP AND MAGNETIZATION CURRENT REQUIREMENTS
HP/EP MAIN DRIVESHAFT ASSEMBLY (412-040-005-101 AND -103)
204-040-184-001
Nut
6, Figure 1
SET UP:
Place part over a 1.5-inch diameter central conductor.
Current for primary diameters, magnetize at 1990 amps.
214-040-657-003
Inner Coupling
8, Figure 1
SET UP:
Place part over a 2-inch diameter central conductor.
Current for primary diameters, magnetize at 3480 amps.
Optional current for secondary diameters, magnetize at 1440 amps.
SET UP: 5 TURN COIL SHOT:
Disc-shaped portion of part: Place part in bottom of coil.
Magnetize at 3000 amps.
Rotate part 1/4 turn and repeat.
412-A-63-10-00-02A-280B-B
Page 00111-2 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Table 2. Magnetic Particle Inspection (continued)
212-040-686-001
Driveshaft
16, Figure 1
SET UP:
Place part over a 2-inch diameter central conductor.
Current for primary diameters, magnetize at 2000 amps.
SET UP: 5 TURN COIL SHOT:
With part supported on the conducting rod between the contact plates, magnetize the part by placing the coil in positions shown
in the attached diagram with magnetizing force of 2400 amps.
214-010-659-005
Outer Coupling
9, Figure 1
SET UP:
Place part over a 2-inch diameter central conductor.
Current for primary diameters, magnetize at 1760 amps.
Large I.D. of part: Magnetize at three approximately equally spaced radial locations on central conductor.
SET UP: 5 TURN COIL SHOT:
Disc-shaped portion of part: Place part in bottom of coil.
Magnetize at 3000 amps.
Rotate part 1/4 turn and repeat.
NOTES:
1. Magnetization currents provided are applicable to magnetic particle inspection apparatus using Direct Current (DC) . If an
Alternating Current (AC) apparatus is used, adjust the current as follows: AC= 0.667 x DC.
2. Ferrous parts requiring magnetic particle inspection that are not addressed in the attached material, are to be inspected in
accordance with the general procedures outlined in ASTM E1444 standard practices (BHT-ALL-SPM, Chapter 6, Standard
Practices Manual).
3. Part numbers listed apply to all successive dash numbers for that component unless otherwise specified.
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-02A-280B-B
28 OCT 2024 Page 00111-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00040-A-001-01
Figure 1. Main Driveshaft Assembly (412-040-005-101 and -103) (Sheet 1 of 1)
412-A-63-10-00-02A-280B-B
Page 00111-4 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00052-A-001-01
Figure 2. Main Driveshaft Outer Coupling (214-040-659-005) - Damage Limits (Sheet 1 of 4)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-02A-280B-B
28 OCT 2024 Page 00111-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00053-A-001-01
Figure 2. Main Driveshaft Outer Coupling (214-040-659-005) - Damage Limits (Sheet 2 of 4)
412-A-63-10-00-02A-280B-B
Page 00111-6 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00054-A-001-01
Figure 2. Main Driveshaft Outer Coupling (214-040-659-005) - Damage Limits (Sheet 3 of 4)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-02A-280B-B
28 OCT 2024 Page 00111-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00055-A-001-01
Figure 2. Main Driveshaft Outer Coupling (214-040-659-005) - Damage Limits (Sheet 4 of 4)
412-A-63-10-00-02A-280B-B
Page 00111-8 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00060-A-001-01
Figure 3. Main Driveshaft and Nut (412-040-005-101) - Damage Limits (Sheet 1 of 2)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-02A-280B-B
28 OCT 2024 Page 00111-9
BHT-412-CRO
ICN-412-A-631000-B-97499-00004-A-001-01
Figure 3. Main Driveshaft and Nut (412-040-005-101) - Damage Limits (Sheet 2 of 2)
412-A-63-10-00-02A-280B-B
Page 00111-10 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00056-A-001-01
Figure 4. Main Driveshaft Inner Coupling (214-040-657-003) - Damage Limits (Sheet 1 of 4)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-02A-280B-B
28 OCT 2024 Page 00111-11
BHT-412-CRO
ICN-412-A-631000-B-97499-00057-A-001-01
Figure 4. Main Driveshaft Inner Coupling (214-040-657-003) - Damage Limits (Sheet 2 of 4)
412-A-63-10-00-02A-280B-B
Page 00111-12 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00058-A-001-01
Figure 4. Main Driveshaft Inner Coupling (214-040-657-003) - Damage Limits (Sheet 3 of 4)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-02A-280B-B
28 OCT 2024 Page 00111-13
BHT-412-CRO
ICN-412-A-631000-B-97499-00059-A-001-01
Figure 4. Main Driveshaft Inner Coupling (214-040-657-003) - Damage Limits (Sheet 4 of 4)
412-A-63-10-00-02A-280B-B
Page 00111-14 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Main Driveshaft (412-040-005-101 and -103) - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Cadmium plating solution
Epoxy/zinc coating
Epoxy adhesive
Drycleaning solvent
MEK
Cleaning compound
Abrasive cloth or paper
Masking tape
India stone
Clean cloth
C-108
C-208
C-298
C-304
C-309
C-318
C-406
C-426
C-464
C-516
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
Remarks
Procedure
1.
With abrasive cloth or paper (C-406), polish out mechanical and corrosion damage on the driveshaft (16, Figure 1)
that is within the limits shown in Figure 2. Blend the repaired area to a minimum radius of 0.50 inch (12.7 mm). The
finished repair must be 32 RHR or better (BHT-ALL-SPM, Standard Practices Manual).
2.
Touch up the repair areas with cadmium plating solution (C-108). Use only the brush cadmium plate procedure
defined in the BHT-ALL-SPM, Standard Practices Manual.
3.
Polish the nicks and dents in the spline teeth of the driveshaft splines, only to remove any raised material, with a
fine india stone (C-464).
4.
Replace missing or illegible nameplates (15, Figure 1) as follows:
4.1.
Remove the illegible nameplate.
4.2.
Stamp the required information on a new nameplate and bond the plate on the driveshaft as per instructions in the
BHT-ALL-SPM, Standard Practices Manual.
4.3.
Bond an unmarked nameplate, face down to the driveshaft, 180° apart from the marked nameplate for balance
purposes (BHT-ALL-SPM, Standard Practices Manual).
5.
Polish out small nicks and dents, not exceeding 0.030 inch (0.76 mm) across the largest dimension, at the corners at
the ends of the inner and outer gear teeth with a fine india stone (C-464). Do not attempt to polish out the damage on
the face of the coupling gear teeth.
6.
Polish nicks and dents in the teeth of the internal spline of the inner couplings with a fine india stone (C-464), only
to remove any raised material.
7.
Paint the inside of the driveshaft in Area A (Figure 3) only if the existing finish has been damaged. Comply with
the following:
7.1.
Clean the inside of the driveshaft with drycleaning solvent (C-304).
7.2.
Allow the solvent to dry.
7.3.
Prepare the epoxy/zinc coating (C-208) as follows:
NOTE
The epoxy/zinc coating material is supplied in a three-component kit.
7.3.1.
Measure an adequate volume of base material to paint the number of driveshafts that can be painted in 8 hours or less.
7.3.2.
Add an equal volume of the accelerator/ thinner and mix thoroughly.
7.3.3.
Weigh the mixed material.
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-02A-685A-B
28 OCT 2024 Page 00112-1
BHT-412-CRO
7.3.4.
Calculate the required amount of zinc powder to produce 20 to 25% (weight) of the mixed material. For instance,
each 100 grams of base/ thinner mixture requires 20 to 25 grams of zinc powder.
7.3.5.
Weigh out the required amount of zinc powder and add to the base/thinner mixture with constant stirring to achieve
a uniform mixture.
7.3.6.
Allow the mixed material to set for a minimum of 1 hour at room temperature prior to use. Discard the mixed material
if not used within 8 hours after mixing.
7.4.
Mask off the areas of the driveshaft outside Area A (Figure 3) with masking tape (C-426).
7.5.
Apply one coat of epoxy/zinc coating (C-208) to Area A . Seal or plug one end of the driveshaft. Flow the epoxy/zinc
mixture into the hollow driveshaft and slosh as needed to coat the entire surface. Drain excess coating material
from the driveshaft.
NOTE
The material drained from the driveshaft into a clean container may be used on other parts if the 8-hour
pot life is not exceeded.
7.6.
Keep the driveshaft vertical for 1 hour after coating to prevent the coating from puddling on one side.
7.7.
The coating will reach final cure in 72 hours at ambient temperature.
7.8.
The coating may be heat cured as follows:
7.8.1.
Dry at ambient conditions for 2 hours.
7.8.2.
Cure at 150 to 160°F (66 to 71°C) for a minimum of 1 hour.
7.9.
Remove the masking tape.
7.10.
Touch up the small areas that may have been inadvertently missed during the initial application.
7.11.
The coating, after drying, must be free of pits, mud cracking, craters, blisters, and other surface irregularities. The
metallic filler must be evenly dispersed to present a relatively uniform gray appearance. Some dark streaks in
coatings applied by the fill and drain process caused by heavier zinc concentration are permitted.
8.
Replace the visual over temperature indicator TEMP-PLATES on the coupling (Figure 4) if mutilated or discolored,
as follows:
8.1.
Remove the damaged TEMP-PLATES with MEK (C-309) and a clean cloth (C-516). Wipe dry with a clean cloth
(C-516) before MEK evaporates.
THE BONDING SURFACE AND THE TEMP-PLATES MUST BE FREE OF ALL CONTAMINATION.
ANY CONTAMINATION COULD ALLOW THE TEMP-PLATES TO COME OFF OR INDICATE FALSE
TEMPERATURES.
8.2.
Prepare the coupling surface for bonding by scrubbing the area with a clean cloth (C-516) moistened with MEK
(C-309). Wipe dry before MEK evaporates. The surface should be at least 0.050 inch (1.27 mm) larger than the
TEMP-PLATE.
8.3.
Accomplish a water break free test on the prepared bonding surface by applying distilled or demineralized water from
a suitable dispenser (squeeze bottle). The water must flow into a continuous film without gathering into distinct water
droplets within 25 seconds after application. Wipe dry with a clean cloth (C-516). If the coupling bonding surface
does not meet the water break free test and you have ensured the cleaning materials are not contaminated, clean
the coupling bonding surface as follows:
NOTE
Follow the manufacturer's recommendations for proper water mixtures.
8.3.1.
Scrub the coupling bonding surface with a clean cloth (C-516) and cleaning compound (C-318). Follow the cleaning
with a thorough water rinse.
8.3.2.
Thoroughly dry the coupling surface and repeat the water break free test as stated in Step 8.3..
412-A-63-10-00-02A-685A-B
Page 00112-2 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
9.
Install the TEMP-PLATES as follows:
IN ORDER TO PREVENT CONTAMINATION OF THE TEMP-PLATE ADHESIVE BACK, MAKE
SURE THAT WORK AREA AND HANDS ARE THOROUGHLY CLEANED BEFORE WORKING WITH
TEMP-PLATES. DO NOT PRESS OR RUB THE TEMP-PLATE WITH BARE FINGERS DURING
INSTALLATION ON COUPLING AS THIS WILL CONTAMINATE SURFACE.
9.1.
Remove the protective backing from the TEMP-PLATE and carefully position onto the prepared surface.
9.2.
With a clean cloth (C-516), work the TEMP-PLATES into the contour of the coupling. Make sure the TEMP-PLATE
is in full contact with the coupling surface.
NOTE
Apply epoxy adhesive (C-298) to the TEMP-PLATES immediately following the installation of the
TEMP-PLATES on each coupling.
10.
Install epoxy adhesive (C-298) over the TEMP-PLATE as follows:
THE USE OF ANY EPOXY ADHESIVE OTHER THAN SPECIFIED IS NOT AUTHORIZED.
10.1.
Mix epoxy adhesive (C-298) per manufacturer recommendations.
10.2.
With a soft bristled brush (artist brush), vigorously mix the epoxy. A few drops of recommended thinner may be added
during mixing to reduce the viscosity to a level that permits uniform brush application of the mixture and will not run
when applied to a vertical surface. The final viscosity of mixture should be similar to a heavy bodied paint.
TOO THIN OF AN EPOXY COATING MAY SEEP INTO THE TEMP-PLATE CAUSING THE INDICATOR
DOTS TO TURN BLACK, IN WHICH EVENT, THE TEMP-PLATE MUST BE REPLACED.
10.3.
Uniformly apply the epoxy coating over the TEMP-PLATE to the thickness of approximately 0.002 to 0.004 inch (0.05
to 0.10 mm). The coating should totally cover the surface of the TEMP-PLATE and extend approximately 0.250
inch (6.35 mm) beyond the edges of the TEMP-PLATE.
11.
Cure the epoxy coating as follows:
DO NOT EXPOSE THE EPOXY COATING TO OIL, GREASE, CLEANING SOLVENTS, OR OTHER
CHEMICALS DURING CURE.
11.1.
Allow the epoxy coating to cure at room temperature (60 to 100°F (16 to 38°C)) for a minimum of 6 hours prior to
helicopter operation. For best results, allow epoxy to cure overnight.
11.2.
The epoxy coating total curing time can be accelerated by allowing the epoxy coating to cure at room temperature for
1 hour, then place the coupling in a temperature controlled oven for 1 to 2 hours at a temperature of 150 to 180°F (66
to 82°C). An alternate source of heat can be used if temperature does not exceed 180°F (82°C).
NOTE
Following the cure, the TEMP-PLATE should conform to the contour of the coupling and be free of lifted
edges. Indicating dots on the TEMP-PLATES must remain the original white or light gray with no or partial
black discoloration.
Some lifting at the extreme ends of the TEMP-PLATES installed on grooved couplings is permitted
(Figure 4, View A). Lifting is permitted only at the bottom, as shown, and should not exceed 0.030 inch
(0.76 mm).
11.3.
After curing, accomplish an adhesion test by pressing a 1.0-inch (25-mm) wide strip of high adhesion tape over each
TEMP-PLATE and beyond the edge of the epoxy overcoat. Grasp one end of the tape and remove the tape in one
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-02A-685A-B
28 OCT 2024 Page 00112-3
BHT-412-CRO
abrupt motion. Lifting or peeling of the epoxy coating or TEMP-PLATE is not permitted and requires replacement of
the TEMP-PLATE. Repeat Step 8. through Step 11..
12.
Treat the repaired cadmium surfaces with cadmium plating solution (C-108). Refer to the BHT-ALL-SPM, Standard
Practices Manual for procedures.
412-A-63-10-00-02A-685A-B
Page 00112-4 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00040-A-001-01
Figure 1. Main Driveshaft Assembly (412-040-005-101 and -103) (Sheet 1 of 1)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-02A-685A-B
28 OCT 2024 Page 00112-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00060-A-001-01
Figure 2. Main Driveshaft and Nut (412-040-005-101) - Damage Limits (Sheet 1 of 2)
412-A-63-10-00-02A-685A-B
Page 00112-6 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00004-A-001-01
Figure 2. Main Driveshaft and Nut (412-040-005-101) - Damage Limits (Sheet 2 of 2)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-02A-685A-B
28 OCT 2024 Page 00112-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00061-A-001-01
Figure 3. Main Driveshaft (412-040-005-101 and -103) - Painted Area (Sheet 1 of 1)
412-A-63-10-00-02A-685A-B
Page 00112-8 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00052-A-001-01
Figure 4. Main Driveshaft Outer Coupling (214-040-659-005) - Damage Limits (Sheet 1 of 4)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-02A-685A-B
28 OCT 2024 Page 00112-9
BHT-412-CRO
ICN-412-A-631000-B-97499-00053-A-001-01
Figure 4. Main Driveshaft Outer Coupling (214-040-659-005) - Damage Limits (Sheet 2 of 4)
412-A-63-10-00-02A-685A-B
Page 00112-10 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00054-A-001-01
Figure 4. Main Driveshaft Outer Coupling (214-040-659-005) - Damage Limits (Sheet 3 of 4)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-02A-685A-B
28 OCT 2024 Page 00112-11
BHT-412-CRO
ICN-412-A-631000-B-97499-00055-A-001-01
Figure 4. Main Driveshaft Outer Coupling (214-040-659-005) - Damage Limits (Sheet 4 of 4)
412-A-63-10-00-02A-685A-B
Page 00112-12 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Main Driveshaft (412-040-005-101 and -103) - Lubrication
Procedure
1.
The inspection of the driveshaft couplings and the internal inspection of the driveshaft for corrosion is
required when the driveshaft is lubricated at the interval designated in the BHT-412-MM, Chapter 5. Refer to
412-A-63-10-00-02A-530A-B / 00107, 412-A-63-10-00-02A-258A-B / 00108 and 412-A-63-10-00-02A-280A-B
/ 00109, 412-A-63-10-00-02A-240A-B / 00113, and 412-A-63-10-00-02A-710A-B / 00114 for instructions to
disassemble, clean, inspect, lubricate, and assemble the driveshaft.
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-02A-240A-B
28 OCT 2024 Page 00113-1
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-02A-240A-B
Page 00113-2 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Main Driveshaft (412-040-005-101 and -103) - Assembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Extension Bar, 3/4 Drive
Wrench
Wrench Set
L-122
T101306
T103063
1
1
1
Remarks
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Lubricant
C-015
AR
Remarks
Procedure
1.
Lubricate a new packing (10, Figure 1) with lubricant (C-015) and install in the groove in the boot assembly (11).
NOTE
The recording of the coupling serial numbers to facilitate reassembly is no longer required. It is a desirable
maintenance practice to match the serial numbers of the couplings in order to reassemble the couplings
into the original position.
2.
Select the outer coupling (9) and the inner coupling (8) that are to be assembled.
NOTE
Add running torque of bolt (14) to the actual torque.
3.
Position the outer coupling (9) on the boot assembly (11). Install the six bolts (14), washers (13), and nuts (12).
Torque the bolts 70 to 90 inch-pounds (7.91 to 10.17 Nm). Position the coupling with the boot assembly down
on the work bench.
NOTE
In the Step 4., completely coat the inner and outer coupling teeth with lubricant (C-015).
4.
Lubricate the inner coupling (8) with lubricant (C-015). Hand pack the lubricant (C-015) evenly over the full length
of the gear teeth of the outer coupling (9).
5.
Position the inner coupling (8) into the outer coupling (9). Make sure the inner coupling is installed into the lip of
the boot assembly (11).
6.
Lightly coat the spring retainer (7), locking spring (5), centering spring (4), nut (6), and threads and splines of
the driveshaft (16) with lubricant (C-015).
7.
Place the driveshaft (16) in a suitable support. Install the inner and outer couplings (8 and 9) on the driveshaft.
8.
Position the spring retainer (7) in the driveshaft (16). Install the nut (6) finger tight.
9.
Position the wrench (T101306) (2, Figure 2) in the nut (3).
10.
Position the wrench set (T103063) (5) on the outer coupling (8).
THE TEETH OF INNER COUPLING (4) SHALL FULLY ENGAGE SPLINES OF OUTER COUPLING (8)
BEFORE NUT (3) IS TORQUED.
11.
Insert the extension bar, 3/4 drive (L-122) (1) through the plate of the wrench set (T103063) (5) and engage the
wrench (T101306) (2). Torque the nut (3) 150 to 200 foot-pounds (204 to 271 Nm).
12.
Remove the tools used in Step 9., Step 10., and Step 11..
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-02A-710A-B
28 OCT 2024 Page 00114-1
BHT-412-CRO
13.
Install the locking spring (5, Figure 1). Make sure that the tang of the locking spring is fully engaged in the hole in
the nut (6) and the slot in the driveshaft (16). Check the boot assembly (11) for wrinkles. If wrinkles are found,
loosen and retorque the nut.
14.
Hand pack the lubricant (C-015) over the full length of the gear teeth to a depth of 0.15 to 0.25 inch (3.8 to 6.4
mm) over the outer coupling (9) spline teeth (View A).
15.
Lightly coat the new packing (3) with lubricant (C-015).
16.
Install the packing (3) on the retainer plate (2).
17.
Put the centering spring (4) in position on the retainer plate (2) and install them on the outer coupling (9).
AFTER INSTALLATION OF NEW PACKING (3), CHECK THAT NO RUBBER SLIVERS ARE PRESENT
INDICATING PACKING WAS DAMAGED DURING INSTALLATION.
18.
Install the retaining ring (1) in the groove of the outer coupling (9). Inspect the ring for proper seating in the groove.
19.
Install the outer coupling (17) and associated parts in the same manner as outlined in Step 1. through Step 17.. Make
sure the mounting holes in the flange of the outer coupling (9) are aligned with the ones on the outer coupling (17)
within 2.0°.
20.
Inspect the boot assembly (11) for damage that may have occurred during the assembly. Wrinkles are caused by
misindexing the coupling teeth. Tears are usually caused during torquing of the nut (6).
21.
If not previously accomplished, apply the TEMP-PLATES to the driveshaft outer couplings in accordance with the
procedures in 412-A-63-10-00-02A-685A-B / 00112.
22.
The driveshaft assembly shall be tagged with the date of lubrication if the main driveshaft assembly is to be returned
to stock and an entry made in the component historical record.
412-A-63-10-00-02A-710A-B
Page 00114-2 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00040-A-001-01
Figure 1. Main Driveshaft Assembly (412-040-005-101 and -103) (Sheet 1 of 1)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-02A-710A-B
28 OCT 2024 Page 00114-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00051-A-001-01
Figure 2. Wrench (T101306) - Tool Application (Sheet 1 of 1)
412-A-63-10-00-02A-710A-B
Page 00114-4 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Mast Assembly - Configuration
Procedure
1.
The Model 412 helicopters are delivered with the mast assembly configurations shown in Table 1.
1.1.
Use the information in Table 2 and Table 3, as applicable, to verify the configuration or to upgrade the mast assembly.
The components listed below an assembly dash number are included in that specified configuration.
1.2.
Any noted mast assembly can be upgraded to a newer configuration. When an assembly is upgraded, all applicable
Alert Service Bulletins (ASB) and Technical Bulletins (TB) must be incorporated (Table 2 and Table 3), as applicable.
1.3.
Identify the upgraded mast assembly with the correct configuration dash number that you defined in Step 1. as follows:
1.3.1.
Use a vibrating tool to mark the data plate of the mast assembly. The depth of the vibroetch must not exceed
0.005 inch (0.13 mm).
Example: 412-040-366-113 -121FM
NOTE
Table 2 and Table 3, as applicable, lists all the mast assembly configurations. For the mast assembly to
be correctly configured, all the parts listed in a selected column must be assembled together.
A partial upgrade does not qualify for a data plate or Historical Service Record (HSR) identification change.
1.4.
Use the information in Table 4 and Table 5, as applicable, to verify the configuration of the the mast pole assembly.
The components listed below an assembly dash number are included in that specified configuration.
1.5.
Following an upgrade of the mast assembly, make an entry in the HSR of the mast assembly to show:
- The new part number (P/N)
- The new component inspection interval, as applicable
- The new retirement life of the mast assembly parts, as applicable
- That the configuration of the mast assembly was upgraded
Table 1. Mast Assembly Versus Helicopter Serial Number
MAST ASSEMBLY PART NUMBER
HELICOPTER SERIAL NUMBER
412-040-366-103
S/N 33001 through 33036
S/N 33037 through 33213
412-040-366-105
S/N 34001 through 34024
S/N 36001 through 36019
S/N 36020 through 36029
412-040-366-109
S/N 36031 and 36032
S/N 36034 through 36039
S/N 36030 and 36033
412-040-366-111
S/N 36040 through 36096
S/N 34025 through 34036
412-040-366-113
S/N 36097 through 36494
412-040-366-115
S/N 46400 through 46458
412-040-366-117 (4)
S/N 46459 through 46499
412-040-366-119
Spare (before S/N 36020)
412-040-366-121
S/N 36495 through 36670
412-040-366-123
Spare (S/N 46400 through 46499)
412-040-366-125 (1)
Spare (before S/N 36020)
412-040-366-127 (2) (4)
Spare (S/N 46400 through 46499)
Applicable to: ALL
412-A-63-10-00-00A-398A-B
ECCN EAR99
31 MAY 2023 Page 00115-1
BHT-412-CRO
Table 1. Mast Assembly Versus Helicopter Serial Number (continued)
MAST ASSEMBLY PART NUMBER
HELICOPTER SERIAL NUMBER
S/N 36671 through 36999
412-040-366-129 (3)
S/N 37002 through 37999
NOTES:
1
Latest spares configuration for helicopters not equipped with the mast torque indicating system.
2
Latest spares configuration.
3
Latest production configuration for helicopters equipped with the mast torque indicating system.
4
Used with the Slope Landing Retrofit Kit (BHT-412-SI-62).
Table 2. Mast Assembly - Configuration
NOMENCLATURE
PART NUMBER
NOTES
MAST ASSEMBLY 412-040-366
-103 (1) (2)
-105 (1) (3)
-109 (4) (5)
-111 (4) (6)
-113 (4) (7) (21) (24)
-115 (25)
-117 (26) (27)
Mast Pole Assembly
412-040-101-105
(8)
X
412-040-101-109
(8)
X
412-040-101-121
(8)
X
412-040-101-125
(8)
X
412-040-101-129
(8)
412-A-63-10-00-00A-398A-B
Applicable to: ALL
Page 00115-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Table 2. Mast Assembly - Configuration (continued)
X
412-040-101-133
(8)
X
412-040-101-135
(8)
X
Lock Ring
412-040-108-101
X
X
X
X
X
X
X
Sleeve
29810-8056
(9) (28)
X
X
X
X
X
X
536841
(10)
X
Seal
29940-2023B
(11)
X
X
X
X
X
29990-2082
(11) (12)
X
Applicable to: ALL
412-A-63-10-00-00A-398A-B
ECCN EAR99
31 MAY 2023 Page 00115-3
BHT-412-CRO
Table 2. Mast Assembly - Configuration (continued)
412-340-001-101
(11)
X
Nut
412-040-104-101
(13)
X
X
X
X
X
412-040-104-103
(13)
X
X
Plate Assembly
412-040-103-101
X
X
X
X
X
X
X
Bearing
214-040-125-003
(14)
X
X
X
X
X
214-040-125-101
(29)
X
X
Liner
412-040-102-101
(15)
X
X
X
X
X
X
X
412-A-63-10-00-00A-398A-B
Applicable to: ALL
Page 00115-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Table 2. Mast Assembly - Configuration (continued)
Oil Slinger
412-040-105-101
X
X
X
X
X
X
X
Race
204-040-270-005
(16)
X
204-040-270-101
(17)
X
X
X
X
X
X
Nut
204-040-309-001
(18)
X
204-040-309-101
(19)
X
X
X
X
412-040-524-101
(20)
X
X
Rivet
CR4523-4-04
X
X
Ring
Applicable to: ALL
412-A-63-10-00-00A-398A-B
ECCN EAR99
31 MAY 2023 Page 00115-5
BHT-412-CRO
Table 2. Mast Assembly - Configuration (continued)
M27426-3162C
X
X
X
Lock Ring
412-040-516-101
X
X
X
Nut
412-040-515-101
X
X
X
Ring
M27426-3174C
X
X
X
Plug
412-040-514-101
X
X
X
Rotor
412-040-519-101
(22)
X
X
X
412-040-525-101
(23)
X
X
NOTES:
1
Used on helicopters with no mast torque indicating system.
412-A-63-10-00-00A-398A-B
Applicable to: ALL
Page 00115-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Table 2. Mast Assembly - Configuration (continued)
2
Replaced by 412-040-366-105.
3
Replaced by 412-040-366-119.
4
Used on helicopters with mast torque indicating system.
5
Used with monopole sensor 412-375-004-105. Can be upgraded to -111 configuration for use with monopole sensor
412-375-004-109. Refer to TB 412-01-179.
6
Replaced by 412-040-366-113.
7
Replaced by 412-040-366-121.
8
For configuration details refer to Table 4.
9
Used with seals 29940-2023B or 29990-2082.
10
Used with seals 412-340-001-101 or 412-340-012-101.
11
Replaced by seal 412-340-012-101.
12
Seal 29990-2082 has no production effectivity. Sold in spares only.
13
Nut 412-040-104-101 replaced by nut 412-040-104-103. The torque applied on the -103 nut is lower than the torque
applied on the -101 nut. Refer to the BHT-412-MM.
14
Replaced by 214-040-125-101.
15
Replaced by liner 412-040-102-103 and packing 412-340-011-101 as a unit. Refer to TB 412-08-218 or TB 412CF-08-90.
16
Race 204-040-270-005 has a width of 0.750 inch (19.05 mm).
17
Race 204-040-270-101 has a width of 1.500 inches (38.1 mm).
18
Nut 204-040-309-001 has standard right hand threads.
19
Nut 204-040-309-101 has left hand threads.
20
Nut 412-040-524-101 has left hand threads. Used with riveted type rotor.
21
Can be converted to 412-040-366-117FM for use with the 412-704-012 Slope Landing Retrofit Kit (BHT-412-SI-62).
22
This rotor is bonded to the mast.
23
This rotor is riveted to the mast.
24
Can be upgraded to -129 provided that TB 412-14-231 is done.
25
Replaced by 412-040-366-117.
26
Replaced by 412-040-366-123.
27
Can be upgraded to -127 provided that TB 412CF-14-103 is done.
28
Used with seal 29990-2082. Applicable to helicopters S/N 46400 through 46499.
29
Replaced by 412-340-125-101.
Table 3. Mast Assembly - Configuration
NOMENCLATURE
PART NUMBER
NOTES
MAST ASSEMBLY 412-040-366
-119 (1) (13) (14)
-121 (3) (15) (16)
-123 (2) (17)
-125 (1)
-127
-129 (3)
Mast Pole Assembly
412-040-101-127
(4)
X
Applicable to: ALL
412-A-63-10-00-00A-398A-B
ECCN EAR99
31 MAY 2023 Page 00115-7
BHT-412-CRO
Table 3. Mast Assembly - Configuration (continued)
X
412-040-101-129
(4)
X
X
412-040-101-133
(4)
412-040-101-135
(4)
X
X
Lock Ring
412-040-108-101
X
X
X
X
X
X
Sleeve
536841
(5)
X
X
X
X
X
X
Seal
412-340-001-101
(6)
X
X
X
412-340-012-101
X
X
X
Nut
412-040-104-103
(7)
X
X
X
412-A-63-10-00-00A-398A-B
Applicable to: ALL
Page 00115-8 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Table 3. Mast Assembly - Configuration (continued)
X
X
X
Plate Assembly
412-040-103-101
X
X
X
X
X
X
Packing
412-340-011-101
(8)
X
X
X
X
X
X
Bearing
214-040-125-101
(18)
X
X
X
X
X
X
Liner
412-040-102-103
(8)
X
X
X
X
X
X
Oil Slinger
412-040-105-101
X
X
X
X
X
X
Race
204-040-270-101
(9)
X
X
X
X
X
X
Nut
204-040-309-101
(10)
X
X
Applicable to: ALL
412-A-63-10-00-00A-398A-B
ECCN EAR99
31 MAY 2023 Page 00115-9
BHT-412-CRO
Table 3. Mast Assembly - Configuration (continued)
412-040-524-101
(11)
X
X
X
X
Rivet
CR4523-4-04
X
X
X
X
Rotor
412-040-525-101
(12)
X
X
X
X
NOTES:
1
Used on helicopters with no mast torque indicating system.
2
Replaced by 412-040-366-127.
3
Used on helicopters with mast torque indicating system.
4
For configuration details refer to Table 4.
5
Used with seals 412-340-001-101 or 412-340-012-101.
6
Replaced by 412-340-012-101.
7
Nut 412-040-104-101 replaced by nut 412-040-104-103. The torque applied on the -103 nut is lower than the torque
applied on the -101 nut. Refer to BHT-412-MM.
8
Packing 412-340-011-101 is used with liner 412-040-102-103. Refer to TB 412-08-218 or TB 412-CF-08-90.
9
Race 204-040-270-101 has a width of 1.500 inches (38.1 mm).
10
Nut 204-040-309-101 has left hand threads.
11
Nut 412-040-524-101 has left hand threads. Used with riveted type rotor.
12
This rotor is riveted to the mast.
13
Replaced by 412-040-366-125.
14
Can be upgraded to -125 provided that TB 412-14-231 is done.
15
Replaced by 412-040-366-129.
16
Can be upgraded to -129 provided that TB 412-14-231 is done.
17
Can be upgraded to -127 provided that TB 412CF-14-103 is done.
18
Replaced by 412-340-125-101.
412-A-63-10-00-00A-398A-B
Applicable to: ALL
Page 00115-10 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Table 4. Mast Pole Assembly - Configuration
MAST POLE ASSEMBLY 412-040-101
NOMENCLATURE
PART NUMBER
Mast
412-040-101-107
NOTES
-105 (1) (2)
-109 (1) (3) -113 (1) (4)
-117 (1)
(4) (5)
X
X
412-040-101-119
X
412-040-101-123
100-024-1
X
X
X
X
100-099-1
X
100-141-1
412-040-113-101
X
X
412-040-101-115
Plug
-125 (6) (9)
(7) (8)
X
412-040-101-111
Plate
-121 (6)
X
(1) (10)
X
X
X
X
NOTES:
1
Used on helicopters with no mast torque indicating system.
2
Replaced by 412-040-101-113.
3
Replaced by 412-040-101-117.
4
Spares configuration.
5
Replaced by 412-040-101-127.
6
Used on helicopters with mast torque indicating system.
7
Used with monopole sensor 412-375-004-105. Refer to TB 412-01-179.
8
Can be replaced by 412-040-101-125, if TB 412-01-179 is done.
9
Used with monopole sensor 412-375-004-109. Refer to TB 412-01-179.
10
Plug 412-010-113-101 has major outside diameter of 2.88 inches (73.2 mm) and the 412-010-113-103 has a major
outside diameter of 2.93 inches (74.4 mm).
Table 5. Mast Pole Assembly - Configuration
NOMENCLATURE
PART NUMBER
NOTES
MAST POLE ASSEMBLY 412-040-101
-127 (1)
-129 (2) (5) (3)
-133
-135
Mast
412-040-101-123
X
X
412-040-101-131
(3)
X
X
Sleeve
412-040-110-101
X
Applicable to: ALL
412-A-63-10-00-00A-398A-B
ECCN EAR99
31 MAY 2023 Page 00115-11
BHT-412-CRO
Table 5. Mast Pole Assembly - Configuration (continued)
X
Plate
100-140-1
X
100-141-1
X
X
X
Plug
412-040-113-103
(1) (4)
X
NOTES:
1
Used on helicopters with no mast torque indicating system.
2
Used on helicopters with mast torque indicating system.
3
Lower section has rivet holes for installation of riveted rotor 412-040-525-101.
4
Plug 412-010-113-101 has major outside diameter of 2.88 inches (73.2 mm) and the 412-010-113-103 has a major
outside diameter of 2.93 inches (74.4 mm).
5
Can be converted to 412-040-101-135FM. Use with Slope Landing Retrofit Kit (BHT-412-SI-62).
412-A-63-10-00-00A-398A-B
Applicable to: ALL
Page 00115-12 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Transmission Main Rotor Mast Assemblies (412-040-366-103/-105 and -125) - Disassembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Mast Nut
Clevis Assembly
Washer
Power Wrench Kit
Anchor Plate
Wrench
204-010-481-001
204-011-178-001
AN960-1016
T100965
T100968
T101456 or
412-240-027-101
Plate Assembly
T101901
Bearing Installation and Removal Tool T101937
T101939
Rod Connector
Bolt Assembly
T101941
T103163
Tie Rod Spacer
Tie Bolt
T103164
T103165
Splined Adapter
T103166
Screw and Plate Set
Thrust Plate
T103167
T103178
Socket Wrench
T103192
Sleeve Protector
T103260-121
Rod Set
Qty
Remarks
1
1
2
1
1
1
1
1
2
2
2
2
1
1
1
1
1
2
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Masking tape
C-426
AR
Remarks
Procedure
NOTE
SN: 36020-36999 or 37002-37999 or 46400-46499 412-570-001-103: Installed:
Refer to 412-A-63-10-00-05A-530A-B / 00121.
1.
Refer to the Airworthiness Limitations Schedule in the applicable Maintenance Manual for airworthiness life on the
mast assembly components. Identify the components that have accumulated hours for retirement.
DO NOT TOUCH PORTION OF MAST THAT IS NORMALLY INSIDE TRANSMISSION WITH BARE
HANDS.
WHEN LIFTING MAST WITH HOIST, USE mast nut (204-010-481-001) AND clevis assembly
(204-011-178-001). DO NOT USE CAP ASSEMBLY THAT IS USED TO SECURE MAIN ROTOR HUB
TO MAST WHEN MAST AND HUB ARE INSTALLED IN HELICOPTER.
NOTE
If the main rotor mast is being disassembled for replacement of parts and not for overhaul, disassemble
only to the extent required to replace the parts.
2.
If not previously done, remove the main rotor mast assembly (BHT-412-MM-6, Chapter 63).
Applicable to: ALL
412-A-63-10-00-04A-530A-B
ECCN EAR99
31 MAY 2023 Page 00116-1
BHT-412-CRO
3.
Hoist the mast assembly (1, Figure 1) into position over a work bench equipped with padded V-blocks. Place the
mast in the V-blocks in a horizontal position (Figure 2).
4.
Place a layer of protective paper on the mast and secure with masking tape (C-426) to avoid scratching the mast
during the disassembly procedures.
Applicable: TB 412-14-231: Post:
5.
Remove the sealant from the top of the lock ring (4, Figure 1) with a plastic scraper.
6.
Cut and remove lockwire from the screws (3).
7.
Remove four screws (3). Cut sealant around the lock ring (4) with a plastic scraper. Remove the lock ring.
8.
Remove four screws (24). Remove the mast bearing retaining plate (11) and the shim (12). If the same parts are to
be reinstalled on the mast assembly (1), index the shim for reinstallation.
9.
Cut the sealant around the seal (6) with a plastic scraper. Remove the seal from the mast bearing retaining plate
(11) and discard the seal.
10.
Remove the mast bearing retention nut (2, Figure 2) as follows:
10.1.
Position the sleeve protector (T103192) (7) on the mast bearing retention nut (2).
10.2.
Position the socket wrench (T103178) (6) on the mast bearing retention nut (2).
10.3.
Put the power wrench kit (T100965) (5) on the socket wrench (T103178) (6).
10.4.
Position the anchor plate (T100968) (4) on the power wrench kit (T100965) (5).
10.5.
Position the splined adapter (T103165) (3) on the main rotor mast (1). Make sure that the splined adapter fully
engages the splines of the mast and the splines of the anchor plate (T100968) (4).
10.6.
Tighten the two thumb screws (11).
10.7.
Position the steel bar (12) as illustrated.
10.8.
Remove two cotter pins from the bearing race retention nut (8). Discard the cotter pins.
NOTE
Determine whether the bearing race retention nut (8) has right-hand or left-hand threads. Refer to
Figure 1, Detail B, for a description of the type of threads used on the two masts.
10.9.
Position the wrench (T101456 or 412-240-027-101) (9, Figure 2) on the bearing race retention nut (8).
10.10.
Position the torque wrench (10) on the wrench (T101456 or 412-240-027-101) (9) and loosen the bearing race
retention nut (8). Remove the torque wrench and the wrench. Remove the nut and the bearing race.
10.11.
Position the torque wrench (13) on the power wrench kit (T100965) (5). Operate the power wrench to turn the socket
wrench (T103178) (6) and loosen the mast bearing retention nut (2).
10.12.
Remove all the tools installed in Step 10.1. through Step 10.11..
11.
Remove the bearing (26) from the mast as follows:
NOTE
Refer to Figure 2, Detail C and Detail D, to install tools on the mast for bearing removal.
11.1.
Position the bearing installation and removal tool (T101937) (24) on the main rotor mast (1).
11.2.
Position the plate assembly (T101901) (22) on the main rotor mast (1).
11.3.
Install two bolt assembly (T101941) (23).
11.4.
Assemble the rod set (T103260-121) (21), tie bolt (T103164) (19), rod connector (T101939) (20), tie rod spacer
(T103163) (17), washer (AN960-1016) (16), and nut (5/8-11 UNC) (15). Make sure that equal thread engagement of
the two rods is obtained in the rod connector. Assemble the opposite rods and connector in the same manner.
412-A-63-10-00-04A-530A-B
Applicable to: ALL
Page 00116-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
11.5.
Place the thrust plate (T103167) (18) on the end of the mast. Position both tie bolt (T103164) (19) in the slots of
the screw and plate set (T103166) (14) and tighten the nuts (5/8-11 UNC) (15). Tighten the large screw in the
center of the plate set to pull the bearing (26) from the mast. When the bearing is clear of the journal on the mast,
remove the tools installed in Step 11.1. through Step 11.4.. Remove the oil slinger (25), bearing, and liner (27) from
the main rotor mast (1).
12.
Use a hollow, cylindrical sleeve to support the outer race of the bearing (26). Position a similar sleeve on the liner (27)
and press the liner off the bearing.
13.
Remove the cork plug (29, Figure 1).Discard the cork plug.
Applicable to: ALL
412-A-63-10-00-04A-530A-B
ECCN EAR99
31 MAY 2023 Page 00116-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00041-A-001-01
Figure 1. Transmission Rotor Mast Assembly (412-040-366-103/-105 and -125) (Sheet 1 of 4)
412-A-63-10-00-04A-530A-B
Applicable to: ALL
Page 00116-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00042-A-001-01
Figure 1. Transmission Rotor Mast Assembly (412-040-366-103/-105 and -125) (Sheet 2 of 4)
Applicable to: ALL
412-A-63-10-00-04A-530A-B
ECCN EAR99
31 MAY 2023 Page 00116-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00043-A-001-01
Figure 1. Transmission Rotor Mast Assembly (412-040-366-103/-105 and -125) (Sheet 3 of 4)
412-A-63-10-00-04A-530A-B
Applicable to: ALL
Page 00116-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00044-A-001-01
Figure 1. Transmission Rotor Mast Assembly (412-040-366-103/-105 and -125) (Sheet 4 of 4)
Applicable to: ALL
412-A-63-10-00-04A-530A-B
ECCN EAR99
31 MAY 2023 Page 00116-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00062-A-001-01
Figure 2. Transmission Main Rotor Mast Assembly/Disassembly Tool (412-040-366-103/-105 and -125) - Tool
Application (Sheet 1 of 3)
412-A-63-10-00-04A-530A-B
Applicable to: ALL
Page 00116-8 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00063-A-001-01
Figure 2. Transmission Main Rotor Mast Assembly/Disassembly Tool (412-040-366-103/-105 and -125) - Tool
Application (Sheet 2 of 3)
Applicable to: ALL
412-A-63-10-00-04A-530A-B
ECCN EAR99
31 MAY 2023 Page 00116-9
BHT-412-CRO
ICN-412-A-631000-B-97499-00064-A-001-01
Figure 2. Transmission Main Rotor Mast Assembly/Disassembly Tool (412-040-366-103/-105 and -125) - Tool
Application (Sheet 3 of 3)
412-A-63-10-00-04A-530A-B
Applicable to: ALL
Page 00116-10 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Transmission Main Rotor Mast Assemblies (412-040-366-103/-105 and -125) - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Drycleaning solvent
MEK
Clean cloth
C-304
C-309
C-516
AR
AR
AR
Remarks
Procedure
NOTE
SN: 36020-36999 or 37002-37999 or 46400-46499 412-570-001-103: Installed:
Refer to 412-A-63-10-00-05A-258A-B / 00122.
1.
Remove old sealant from the mast bearing retainer plate (11, Figure 1) with a plastic scraper and a clean cloth
(C-516) moistened with MEK (C-309).
2.
Clean all the mast assembly components with drycleaning solvent (C-304). If jet No. 8 (19) is clogged, determine the
source of the material that is clogging the jet.
3.
Dry the parts with low pressure, filtered compressed air. Do not allow the bearings to spin while drying.
Applicable to: ALL
412-A-63-10-00-04A-258A-B
ECCN EAR99
31 MAY 2023 Page 00117-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00041-A-001-01
Figure 1. Transmission Rotor Mast Assembly (412-040-366-103/-105 and -125) (Sheet 1 of 4)
412-A-63-10-00-04A-258A-B
Applicable to: ALL
Page 00117-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00042-A-001-01
Figure 1. Transmission Rotor Mast Assembly (412-040-366-103/-105 and -125) (Sheet 2 of 4)
Applicable to: ALL
412-A-63-10-00-04A-258A-B
ECCN EAR99
31 MAY 2023 Page 00117-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00043-A-001-01
Figure 1. Transmission Rotor Mast Assembly (412-040-366-103/-105 and -125) (Sheet 3 of 4)
412-A-63-10-00-04A-258A-B
Applicable to: ALL
Page 00117-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00044-A-001-01
Figure 1. Transmission Rotor Mast Assembly (412-040-366-103/-105 and -125) (Sheet 4 of 4)
Applicable to: ALL
412-A-63-10-00-04A-258A-B
ECCN EAR99
31 MAY 2023 Page 00117-5
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-04A-258A-B
Applicable to: ALL
Page 00117-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Transmission Main Rotor Mast Assemblies (412-040-366-103/-105 and -125) - Inspection
Procedure
NOTE
SN: 36020-36999 or 37002-37999 or 46400-46499 412-570-001-103: Installed:
Refer to 412-A-63-10-00-05A-280A-B / 00123.
1.
Inspect the main rotor mast in accordance with Figure 1.
2.
Inspect the following parts by magnetic particle inspection. Demagnetize the parts after the magnetic particle
inspection. Refer to Table 2 and the BHT-ALL-SPM, Standard Practices Manual for the procedure.
Figure 2INDEX NUMBER
NOMENCLATURE
1
Mast Assembly
4
Lock Ring
7
Mast Bearing Retention Nut
23
Bearing Liner
25
Oil Slinger
27
Nut
Table 2. Magnetic Particle Inspection
PART NUMBER
NOMENCLATURE
ITEM AND FIGURE
SET UP AND MAGNETIZATION CURRENT REQUIREMENTS
MAST ASSEMBLY (412-040-366-103)
412-040-101-105
Mast Assembly
1, Figure 2
SET UP:
Place part over a 2-inch diameter central conductor.
Current for primary diameters, magnetize at 2600 amps.
Optional current for secondary diameters, magnetize at 1720 amps.
SET UP: 5 TURN COIL SHOT:
Hold part in bottom of coil with long axis parallel to coil axis.
Magnetize at 2340 amps.
Magnetize at 15-inch intervals along mast.
412-040-102-101
Bearing Liner
23, Figure 2
Refer to 412 HP/EP magnetic particle.
412-040-104-101
Mast Bearing Retention Nut
7, Figure 2
Refer to 412 HP/EP magnetic particle.
412-040-105-101
Oil Slinger
25, Figure 2
SET UP:
Place part over a 2-inch diameter central conductor.
Current for primary diameters, magnetize at 2730 amps.
SET UP: 5 TURN COIL SHOT:
Disc-shaped portion of part: Place part in bottom of coil.
Applicable to: ALL
412-A-63-10-00-04A-280A-B
ECCN EAR99
31 MAY 2023 Page 00118-1
BHT-412-CRO
Table 2. Magnetic Particle Inspection (continued)
Magnetize at 3000 amps.
Rotate part 1/4 turn and repeat.
204-040-309-001
Nut
27, Figure 2
SET UP:
Place part over a 2-inch diameter central conductor.
Current for primary diameters, magnetize at 1290 amps.
Omit coil shot.
NOTES:
1. Magnetization currents provided are applicable to magnetic particle inspection apparatus using Direct Current (DC) . If an
Alternating Current (AC) apparatus is used, adjust the current as follows: AC= 0.667 x DC.
2. Ferrous parts requiring magnetic particle inspection that are not addressed in the attached material, are to be inspected in
accordance with the general procedures outlined in ASTM E1444 standard practices (BHT-ALL-SPM, Chapter 6, Standard
Practices Manual).
3. Part numbers listed apply to all successive dash numbers for that component unless otherwise specified.
3.
Inspect the mast bearing retaining plate (11, Figure 2) by the fluorescent penetrant method (BHT-ALL-SPM, Standard
Practices Manual).
412-A-63-10-00-04A-280A-B
Applicable to: ALL
Page 00118-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00066-A-001-01
Figure 1. Transmission Main Rotor Mast Assembly (412-040-366-103/-105 and -125) - Damage Limits (Sheet 1 of 5)
Applicable to: ALL
412-A-63-10-00-04A-280A-B
ECCN EAR99
31 MAY 2023 Page 00118-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00067-A-001-01
Figure 1. Transmission Main Rotor Mast Assembly (412-040-366-103/-105 and -125) - Damage Limits (Sheet 2 of 5)
412-A-63-10-00-04A-280A-B
Applicable to: ALL
Page 00118-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00068-A-001-01
Figure 1. Transmission Main Rotor Mast Assembly (412-040-366-103/-105 and -125) - Damage Limits (Sheet 3 of 5)
Applicable to: ALL
412-A-63-10-00-04A-280A-B
ECCN EAR99
31 MAY 2023 Page 00118-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00069-A-001-01
Figure 1. Transmission Main Rotor Mast Assembly (412-040-366-103/-105 and -125) - Damage Limits (Sheet 4 of 5)
412-A-63-10-00-04A-280A-B
Applicable to: ALL
Page 00118-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00070-A-001-01
Figure 1. Transmission Main Rotor Mast Assembly (412-040-366-103/-105 and -125) - Damage Limits (Sheet 5 of 5)
Applicable to: ALL
412-A-63-10-00-04A-280A-B
ECCN EAR99
31 MAY 2023 Page 00118-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00041-A-001-01
Figure 2. Transmission Rotor Mast Assembly (412-040-366-103/-105 and -125) (Sheet 1 of 4)
412-A-63-10-00-04A-280A-B
Applicable to: ALL
Page 00118-8 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00042-A-001-01
Figure 2. Transmission Rotor Mast Assembly (412-040-366-103/-105 and -125) (Sheet 2 of 4)
Applicable to: ALL
412-A-63-10-00-04A-280A-B
ECCN EAR99
31 MAY 2023 Page 00118-9
BHT-412-CRO
ICN-412-A-631000-B-97499-00043-A-001-01
Figure 2. Transmission Rotor Mast Assembly (412-040-366-103/-105 and -125) (Sheet 3 of 4)
412-A-63-10-00-04A-280A-B
Applicable to: ALL
Page 00118-10 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00044-A-001-01
Figure 2. Transmission Rotor Mast Assembly (412-040-366-103/-105 and -125) (Sheet 4 of 4)
Applicable to: ALL
412-A-63-10-00-04A-280A-B
ECCN EAR99
31 MAY 2023 Page 00118-11
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-04A-280A-B
Applicable to: ALL
Page 00118-12 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Transmission Main Rotor Mast Assemblies (412-040-366-103/-105 and -125) - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Cadmium plating solution
Abrasive cloth or paper
India stone
C-108
C-406
C-464
AR
AR
AR
Remarks
Procedure
NOTE
SN: 36020-36999 or 37002-37999 or 46400-46499 412-570-001-103: Installed:
Refer to 412-A-63-10-00-05A-685A-B / 00124.
1.
Inspect the mast for the word REWORKED on flange E as illustrated in Figure 1. If the word REWORKED is on the
flange and there is corrosion or mechanical damage on the mast that requires polishing out, reject the mast. Rework
on the mast is permitted one time only. This restriction is not applicable to the mast bearing retaining plate and liner or
to superficial corrosion in Area A and Area F that can be removed with steel wool.
2.
Dress out small burrs, nicks, and scratches on spline O, Figure 1, with a fine india stone (C-464).
3.
Polish out mechanical and corrosion damage on the mast in the areas other than area A and Area F. Also polish
out damage on the bearing retaining plate with fine to medium abrasive cloth or paper (C-406) or a fine india stone
(C-464). If damage after a complete cleanup exceeds the limits of Figure 1, the mast is not repairable. Final polish
the repair area to a surface roughness of 32 RMS or better.
NOTE
If corrosion must be polished out on the mast inside diameter, comply with Note 4 in Figure 1.
NOTE
Cleanup limited to external surface corrosion, which can be removed with steel wool, does not require
the mast to be marked REWORKED.
4.
If damage was polished out on areas of the mast other than Area A, Area F, or the mast bearing retaining plate, mark
the word REWORKED on flange E with a vibrating stylus.
5.
Touch up the rework areas where cadmium plating was removed as follows:
5.1.
If field repair is being accomplished, do not apply cadmium plating solution (C-108) on the inside diameter of the mast
beyond the 6-0 inches (152-mm) limit noted at step 4 in Figure 1.
5.2.
Use only the cadmium plating procedures noted in the BHT-ALL-SPM, Standard Practices Manual.
5.3.
Apply cadmium plating solution (C-108) only in the areas indicated in Figure 2 (BHT-ALL-SPM, Standard Practices
Manual).
6.
Replace missing or illegible nameplates (BHT-ALL-SPM, Standard Practices Manual).
Applicable to: ALL
412-A-63-10-00-04A-685A-B
ECCN EAR99
31 MAY 2023 Page 00119-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00066-A-001-01
Figure 1. Transmission Main Rotor Mast Assembly (412-040-366-103/-105 and -125) - Damage Limits (Sheet 1 of 5)
412-A-63-10-00-04A-685A-B
Applicable to: ALL
Page 00119-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00067-A-001-01
Figure 1. Transmission Main Rotor Mast Assembly (412-040-366-103/-105 and -125) - Damage Limits (Sheet 2 of 5)
Applicable to: ALL
412-A-63-10-00-04A-685A-B
ECCN EAR99
31 MAY 2023 Page 00119-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00068-A-001-01
Figure 1. Transmission Main Rotor Mast Assembly (412-040-366-103/-105 and -125) - Damage Limits (Sheet 3 of 5)
412-A-63-10-00-04A-685A-B
Applicable to: ALL
Page 00119-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00069-A-001-01
Figure 1. Transmission Main Rotor Mast Assembly (412-040-366-103/-105 and -125) - Damage Limits (Sheet 4 of 5)
Applicable to: ALL
412-A-63-10-00-04A-685A-B
ECCN EAR99
31 MAY 2023 Page 00119-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00070-A-001-01
Figure 1. Transmission Main Rotor Mast Assembly (412-040-366-103/-105 and -125) - Damage Limits (Sheet 5 of 5)
412-A-63-10-00-04A-685A-B
Applicable to: ALL
Page 00119-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00071-A-001-01
Figure 2. Main Rotor Mast (412-040-366-103/-105 and -125) - Cadmium Plating Areas (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-04A-685A-B
ECCN EAR99
31 MAY 2023 Page 00119-7
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-04A-685A-B
Applicable to: ALL
Page 00119-8 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Transmission Main Rotor Mast Assemblies (412-040-366-103/-105 and -125) - Assembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Wrench
T101456 or
412-240-027-101
1
Remarks
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Grease
Grease
Epoxy polyamide primer
Shellac varnish
Polyurethane coating
Epoxy primer coating
C-001
C-172
C-204
C-211
C-245
C-246
AR
AR
AR
AR
AR
AR
Sealant
MEK
Adhesive
Denatured alcohol
Sealant
Masking tape
Anti-seize thread compound
Clean cloth
Lockwire
C-251
C-309
C-317
C-326
C-328
C-426
C-452
C-516
C-405
AR
AR
AR
AR
AR
AR
AR
AR
AR
Remarks
Epoxy Polyamide Primer (C-204) can be used as
an alternate.
Procedure
DO NOT TOUCH PORTION OF MAST THAT IS NORMALLY INSIDE TRANSMISSION WITH BARE
HANDS.
WHEN LIFTING MAST WITH HOIST, USE MAST NUT 204-010-481-001 AND CLEVIS ASSEMBLY
204-011-178-001. DO NOT USE CAP ASSEMBLY THAT IS USED TO SECURE MAIN ROTOR HUB
TO MAST.
NOTE
SN: 36020-36999 or 37002-37999 or 46400-46499 412-570-001-103: Installed:
Refer to 412-A-63-10-00-05A-710A-B / 00125.
1.
Place a layer of protective paper on the mast assembly and secure with masking tape (C-426) to avoid scratching
the mast during the assembly procedures.
2.
Before you install the bearing (14, Figure 1) and the mast bearing retention nut (7), apply a coat of epoxy primer
coating (C-246) to the annular groove only. Do not apply primer to the bearing journal or to the threaded area.
3.
Apply grease (C-172) to the mast bearing journal and to the first three threads of the threaded area. Fill the annular
groove with grease.
4.
Install the new cork plug (29) inside the mast assembly (1) with shellac varnish (C-211) (Detail A).
5.
Install the bearing (14) on the mast assembly as follows:
Applicable to: ALL
412-A-63-10-00-04A-710A-B
ECCN EAR99
31 MAY 2023 Page 00120-1
BHT-412-CRO
5.1.
Position the bearing (14) with the V-marks (13) on the bearing inner races aligned and the apex pointing toward the
top of the mast. Align the V-marks (15) on bearing outer races with the apex pointing toward the bottom of the mast.
5.2.
Position a hollow cylindrical metal sleeve of the correct size to contact the bearing outer race on the bearings (14)
and press the bearing into the bearing liner (23). Rotate the bearing inner race to check for freedom of operation
during seating procedure.
5.3.
Place the previously prepared shim (12) in the bearing liner (23) on the outer race of the upper bearing (14). Install the
mast bearing retaining plate (11) on the mast with care to avoid damaging the seal on the mast splines. Secure the
bearing liner to the retaining plate with four screws (24). Measure and record the gap between the bearings and the
plate. The shim should be equal to, or 0.001 to 0.003 inch (0.03 to 0.08 mm) thicker than, the recorded dimension. If
the shim thickness is not within the limits, prepare a shim of the correct dimensions.
5.4.
Remove four screws (24) and separate the bearing liner (23) from the mast bearing retaining plate (11).
NOTE
Refer to Figure 2, Detail D for a sectional view of the bearings, oil slinger, and liner installed on the mast.
5.5.
Position the bearing installation and removal tool (24, Figure 2) on the main rotor mast (1).
5.6.
Position the oil slinger (25), bearings (26), and liner (27) on the main rotor mast (1).
5.7.
Position the plate assembly (T101901) (22) on the main rotor mast (1) and install the two bolt assemblies (T101941)
(23).
5.8.
Put the thrust plate (T103167) (18), screw and plate set (T103166) (14), two rod sets (T103260-121) (21), two
tie rod spacers (T103163) (17), two washers (AN960-1016) (16), and two nuts (5/8-11 UNC) (15) on the main
rotor mast (1). Tighten the nuts.
5.9.
Carefully tighten the large screw in the screw and plate set (T103166) (14) to pull the bearing (26) into position on the
main rotor mast (1). When the bearing is fully seated against the shoulder on the mast, remove the tools installed
in Step 5.5. through Step 5.8..
6.
Make sure that after the bearing (14, Figure 1) installation, the annular groove is filled with grease (C-172). Make
sure that the first three threads of the threaded area have grease. Remove any excess grease from the lower
side area of the bearing.
NOTE
Depending on the helicopter configuration, a mast bearing retention nut (7) 412-040-104-101 or -103
may be applicable for installation. The primary difference between the mast bearing retention nuts (2)
412-040-104-101 and -103 is that the threads of the retention nut -103 are coated with solid film lubricant.
Prior to installation of a retention nut -103, make sure the threads have a coating of solid film lubricant.
If the solid film lubricant coating is damaged or missing, refer to the BHT-ALL-SPM, Standard Practices
Manual for application procedures. The application of solid film lubricant is directly related to the nut -103
torque value specified in the following assembly instructions.
7.
Install the mast bearing retention nut (7) as follows:
NOTE
Refer to Figure 2, Detail B, for a view of the installed bearing retention nut removal/installation tools and
Figure 1, Detail A for the sealing and grease application.
7.1.
Make sure that the mast bearing retention nut (2, Figure 2) has a wear sleeve bonded to the nut prior to installation.
Thread the nut onto the main rotor mast (1) with the splined end of the nut next to the bearing.
7.2.
If the wear sleeve is damaged, install a new wear sleeve on the mast bearing retention nut (2) as follows:
7.2.1.
Protect the bearing from contamination and carefully remove the wear sleeve.
7.2.2.
Remove the adhesive from the mast bearing retention nut (2) and clean with a clean cloth (C-516) moistened
with MEK (C-309).
7.2.3.
Apply adhesive (C-317) to the outside diameter of the mast bearing retention nut (2) and install a new wear sleeve.
7.2.4.
Clean off excess adhesive as required.
7.3.
Position the sleeve protector (T103192) (7) on the mast bearing retention nut (2).
412-A-63-10-00-04A-710A-B
Applicable to: ALL
Page 00120-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
7.4.
Position the socket wrench (T103178) (6) on the mast bearing retention nut (2).
7.5.
Position the power wrench kit (T100965) (5) on the main rotor mast (1) with the lugs and thumb screws (11) toward
the top of the mast.
7.6.
Position the anchor plate (T100968) (4) on the main rotor mast (1). Engage the anchor plate on the lugs of the power
wrench kit (T100965) (5). Tighten the two thumb screws (11).
7.7.
Position the splined adapter (T103165) (3) to engage the splines on the main rotor mast (1) with the splines on the
anchor plate. Make sure that the splines are fully engaged.
7.8.
For the mast bearing retention nut (2) 412-040-104-101, inspect the data plate on the power wrench kit (T100965) (5)
or refer to Figure 1 and determine what torque should be applied with the torque wrench (13, Figure 2).
7.9.
For the mast bearing retention nut (2) 412-040-104-103, inspect the data plate on the power wrench kit (T100965) (5)
or refer to Figure 1 and determine what torque should be applied with the torque wrench (13, Figure 2).
7.10.
Position the steel bar (12) in the anchor plate (T100968) (4).
7.11.
Position the torque wrench (13) on the power wrench kit (T100965) (5).
7.12.
For the mast bearing retention nut (2) 412-040-104-101, make sure that the splines on the tools, mast, and nut
are fully engaged and torque the nut to the lowest torque value
with the torque wrench (13). Rotate the outer
race of the bearing to check for freedom of operation.
7.13.
For the mast bearing retention nut (2) 412-040-104-103, make sure that the splines on the tools, mast, and nut
are fully engaged and torque the nut to the lowest torque value
with the torque wrench (13). Rotate the outer
race of the bearing to check for freedom of operation.
7.14.
Remove the tools installed in the preceding steps.
8.
Position the lock ring (4, Figure 1) on the mast bearing retention nut (7) and check whether the holes for the screws
(3) are aligned. If the holes are not aligned, rotate the lock ring to different splines on the mast. If the holes for
all four screws are still not accessible, reinstall the tools and tighten the retention nut. Repeat as required until
the four screws (3) can be installed, but do not exceed the torque limits noted in Step 7.8. and Step 7.9.. Do not
install the lock ring at this time.
9.
After the holes are aligned for the four screws (3), install the tools as outlined in Step 7.3. through Step 7.11.. These
tools are used to hold the mast during the installation of the bearing race (26) and nut (27).
10.
Install the bearing race (26) and nut (27) as follows:
10.1.
Examine the mast and determine which of the two bearing race and bearing race retention nut configurations are
required. Also, determine whether the threads are right-hand or left-hand (Figure 1, Detail B).
10.2.
Position the bearing race (26) on the mast assembly (1).
10.3.
Apply anti-seize thread compound (C-452) to the threads of the mast assembly (1) and nut (27). Thread the nut
on the mast.
10.4.
Position the wrench (T101456 or 412-240-027-101) (9, Figure 2) and torque the wrench (10) on the nut (27,Figure 1).
. Torque the nut to the low side of the torque . Remove the wrenches and determine whether the two new cotter
pins (28) can be installed. If necessary, apply more torque to the nut, but do not exceed the high side limit.
10.5.
Install the two new cotter pins (28) and bend as described in Figure 1.
10.6.
Remove the tools that were installed in Step 9..
11.
Apply sealant (C-328) to the mast bearing retaining plate (11) and the new seal (6) as follows:
11.1.
Install the new seal (6) in the mast bearing retaining plate (11), as shown in Detail A.
11.2.
Refer to Figure 1 for the definition of the area where the sealant is to be applied.
11.3.
Clean the surfaces where the sealant is to be applied with a clean cloth (C-516) moistened with MEK (C-309). Wipe
dry with a clean cloth (C-516) before the solvent evaporates.
Applicable to: ALL
412-A-63-10-00-04A-710A-B
ECCN EAR99
31 MAY 2023 Page 00120-3
BHT-412-CRO
11.4.
Mix the sealant (C-328) in accordance with the manufacturer’s instructions on the container, or mix 100 parts by
weight of base material to 12 parts by weight of accelerator. Mix thoroughly. The pot life of mixed sealant is 2
hours. Tack free time after applications is 12 to 24 hours.
11.5.
Locate four 0.125 inch (3.18 mm) drain holes in the mast bearing retaining plate (11). Do not allow the sealant to
obstruct these four holes. Apply sealant (C-328) to the area indicated in Figure 1.
12.
Fill the area between the two lips of the new seal (6) with grease (C-001) (Detail A).
13.
Place the previously prepared shim (12) in the bearing liner (23) on the outer race of the upper bearing.
14.
Clean the faying surfaces of bearing liner (23) and mast bearing retaining plate (11) with denatured alcohol (C-326).
IF THE MAST ASSEMBLY IS NOT TO BE INSTALLED IN A TRANSMISSION WITHIN 30 MINUTES OF
SEALANT APPLICATION, CLAMP THE LINER TO THE PLATE ASSEMBLY AND RETIGHTEN THE
4 SCREWS (MS24693-S271). THIS OPERATION MUST BE COMPLETED WITHIN 30 MINUTES OF
SEALANT APPLICATION. THE MAST ASSEMBLY MAY THEN BE STORED UNTIL IT IS REQUIRED.
14.1.
Apply a thin coating of sealant (C-328) to the lower surface of mast bearing retaining plate (11) flange.
14.2.
Attach bearing liner (23) to mast bearing retaining plate (11) with four screws (24), ensuring proper seating of seal (6)
and shims (12). Lightly coat area between seal lips with grease (C-001) (Mobile 28).
14.3.
Immediately prior to installing mast into transmission, clean the faying surfaces of bearing liner (23) flange and top of
case assembly (212-040-059-101) with denatured alcohol (C-326) and apply a thin coating of sealant (C-328) to
the case assembly.
15.
Position jet No. 8 (19) in the mast bearing retaining plate (11) with the new packing (18) and install the screw
(21). Install the cap (20).
16.
Clean the lock ring (4) and apply a light coat of sealant (C-251) to the nut side and a bead of sealant on the thread
adjacent to the nut face.
17.
Position the lock ring (4) on the mast assembly (1) and install four screws (3). Secure the four screws with lockwire
(C-405).
18.
Fill the four holes of the lock ring (4) with sealant (C-251) and apply sealant to cover the exposed threads and
the lock ring screws up to the edge of the lock ring.
19.
After the lock ring (4) installation, apply one coat of epoxy primer coating (C-246) and one coat of polyurethane
coating (C-245) from the outboard edge of the lock ring up to the mast assembly (1) (Detail A).
20.
Apply a bead of sealant (C-251) to cover the exposed threads up to the edge of the lock ring (4). Apply sealant to
create a slope to ensure the water dissipates (Figure 1).
412-A-63-10-00-04A-710A-B
Applicable to: ALL
Page 00120-4 31 MAY 2023
ECCN EAR99
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ICN-412-A-631000-B-97499-00041-A-001-01
Figure 1. Transmission Rotor Mast Assembly (412-040-366-103/-105 and -125) (Sheet 1 of 4)
Applicable to: ALL
412-A-63-10-00-04A-710A-B
ECCN EAR99
31 MAY 2023 Page 00120-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00042-A-001-01
Figure 1. Transmission Rotor Mast Assembly (412-040-366-103/-105 and -125) (Sheet 2 of 4)
412-A-63-10-00-04A-710A-B
Applicable to: ALL
Page 00120-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00043-A-001-01
Figure 1. Transmission Rotor Mast Assembly (412-040-366-103/-105 and -125) (Sheet 3 of 4)
Applicable to: ALL
412-A-63-10-00-04A-710A-B
ECCN EAR99
31 MAY 2023 Page 00120-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00044-A-001-01
Figure 1. Transmission Rotor Mast Assembly (412-040-366-103/-105 and -125) (Sheet 4 of 4)
412-A-63-10-00-04A-710A-B
Applicable to: ALL
Page 00120-8 31 MAY 2023
ECCN EAR99
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ICN-412-A-631000-B-97499-00062-A-001-01
Figure 2. Transmission Main Rotor Mast Assembly/Disassembly Tool (412-040-366-103/-105 and -125) - Tool
Application (Sheet 1 of 3)
Applicable to: ALL
412-A-63-10-00-04A-710A-B
ECCN EAR99
31 MAY 2023 Page 00120-9
BHT-412-CRO
ICN-412-A-631000-B-97499-00063-A-001-01
Figure 2. Transmission Main Rotor Mast Assembly/Disassembly Tool (412-040-366-103/-105 and -125) - Tool
Application (Sheet 2 of 3)
412-A-63-10-00-04A-710A-B
Applicable to: ALL
Page 00120-10 31 MAY 2023
ECCN EAR99
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ICN-412-A-631000-B-97499-00064-A-001-01
Figure 2. Transmission Main Rotor Mast Assembly/Disassembly Tool (412-040-366-103/-105 and -125) - Tool
Application (Sheet 3 of 3)
Applicable to: ALL
412-A-63-10-00-04A-710A-B
ECCN EAR99
31 MAY 2023 Page 00120-11
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-04A-710A-B
Applicable to: ALL
Page 00120-12 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Transmission Main Rotor Mast Assemblies (412-040-366-109 and Subsequent) - Disassembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Mast Nut
Clevis Assembly
Wrench Assembly
Socket
Puller Set
Thrust Plate
Washer
Power Wrench Kit
Anchor Plate
Wrench
204-010-481-001
204-011-178-001
412-240-003-101
412-240-004-101
412-240-005-101
412-240-026-101
AN960-1016
T100965
T100968
T101456 or
412-240-027-101
Plate Assembly
T101901
Bearing Installation and Removal Tool T101937
T101939
Rod Connector
Bolt Assembly
T101941
T103163
Tie Rod Spacer
Tie Bolt
T103164
T103165
Splined Adapter
T103166
Screw and Plate Set
T103178
Socket Wrench
T103192
Sleeve Protector
T103260-121
Rod Set
Qty
Remarks
1
1
1
1
1
1
2
1
1
1
1
1
2
2
2
2
1
1
1
1
2
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Masking tape
C-426
AR
Remarks
Procedure
DO NOT TOUCH PORTION OF MAST THAT IS NORMALLY INSIDE TRANSMISSION WITH BARE
HANDS.
WHEN LIFTING MAST WITH HOIST, USE mast nut (204-010-481-001) AND clevis assembly
(204-011-178-001). DO NOT USE CAP ASSEMBLY THAT IS USED TO SECURE MAIN ROTOR HUB
TO MAST WHEN MAST AND HUB ARE INSTALLED IN HELICOPTER.
NOTE
Mast assembly 412-040-366-109 shall be returned to Bell for rework. Mast assemblies 412-040-366-111
and -115 may be returned to Bell for rework.
NOTE
If the main rotor mast is being disassembled for replacement of parts and not for overhaul, disassemble
only to the extent required to replace the parts.
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-530A-B
28 OCT 2024 Page 00121-1
BHT-412-CRO
NOTE
Refer to Mandatory Airworthiness Limitations Schedule in the BHT-412-MM, Chapter 4 for airworthiness
life on mast assembly components. Identify the components that have accumulated hours for retirement.
1.
Hoist the mast assembly (4, Figure 1) into position over a work bench equipped with padded V-blocks. Place the
mast in the V-blocks in a horizontal position (Figure 2).
2.
Place a layer of protective paper on the mast and secure with masking tape (C-426) to avoid scratching the mast
during disassembly procedures.
USE CARE WHEN REMOVING TORQUEMETER TUBE ASSEMBLY FROM MAST TO PREVENT
DAMAGE TO CADMIUM PLATING OF MAST INSIDE DIAMETER.
3.
Remove the torquemeter tube as follows:
3.1.
Remove the Iockwire and three bolts (1, Figure 1) from the plug (2) and the torquemeter tube assembly (3).Discard
the lockwire.
3.2.
Using three jackscrews, remove the plug (2) from the torquemeter tube assembly (3).
3.3.
Remove the retaining ring (37) and the lock ring (36) from the rotor (32) and the nut (35).
3.4.
Attach the wrench assembly (412-240-003-101) (1, Figure 3).
3.5.
Install the socket (412-240-004-101) (3) through the wrench assembly (412-240-003-101) (1) and remove the nut
(35, Figure 1) from the rotor (32).
NOTE
The bolt used in the torque tube plug removal is a 0.500 X 13 UNC 2.4 inches (61 mm) long.
3.6.
With a 0.500 X 13 UNC-2B die, extend the threads up the shank of the bolt (3, Figure 4) to within 0.50 inch (12.7
mm) of the bolt head.
3.7.
Install the puller set (412-240-005-101) (6) on the lower end of the mast assembly. Thread the bolt (3) into the nut (4).
Tighten the bolt on the shoe (5) to remove the plug (1) from the rotor (32, Figure 1). Remove the retaining ring (33).
3.8.
Cool the lower end of the mast with dry ice to loosen the adhesive holding the rotor (32) in the mast assembly
(4). Pull the rotor from the mast with a suitable puller.
3.9.
Carefully remove the rotor assembly from the mast assembly (4).
4.
Remove the sealant from the top of the lock ring (7) with a plastic scraper.
5.
Remove the four screws (6). Cut the sealant around the lock ring (7) with a plastic scraper. Remove the lock ring.
6.
Remove the four screws (24). Remove the mast bearing retaining plate (14), packing (47), as applicable, and the
shim (15). If same parts are to be reinstalled on the mast assembly (4), index the shim for reinstallation.
7.
Cut the sealant around the seal (8) with a plastic scraper. Remove the seal from mast bearing retaining plate (14).
Discard the seal.
8.
Remove the mast bearing retention nut (2, Figure 2) as follows:
8.1.
Put the sleeve protector (T103192) (7) on the mast bearing retention nut (2).
8.2.
Put the socket wrench (T103178) (6) on the mast bearing retention nut (2).
8.3.
Put the power wrench kit (T100965) (5) on the socket wrench (T103178) (6).
8.4.
Put the anchor plate (T100968) (4) on the power wrench kit (T100965) (5).
8.5.
Put the splined adapter (T103165) (3) on the main rotor mast (1). Make sure that the splined adapter fully engages
the splines of the mast and the splines of the anchor plate (T100968) (4).
8.6.
Tighten the two thumb screws (11).
412-A-63-10-00-05A-530A-B
Page 00121-2 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
8.7.
Position the steel bar (12) as illustrated.
8.8.
Remove the two cotter pins from the bearing race retention nut (8).Discard the cotter pins.
NOTE
Refer to Figure 1, Detail B for a description of the type of threads used on the mast 412-040-101-121.
8.9.
Put the wrench (T101456 or 412-240-027-101) (9, Figure 2) on the bearing race retention nut (8).
8.10.
Put the torque wrench (10) on the wrench (T101456 or 412-240-027-101) (9). Loosen the bearing race retention nut
(8). Remove the torque wrench and the wrench. Remove the bearing race retention nut.
8.11.
Put the torque wrench (13) on the power wrench kit (T100965) (5). Operate the power wrench to turn the socket
wrench (T103178) (6) and loosen the mast bearing retention nut (2).
8.12.
Remove all the tools installed in the preceding Step 8.1. through Step 8.11..
9.
Remove the bearing (26) from the mast as follows:
NOTE
Refer to Figure 2, Detail C and Detail D to install the tools on the mast for the bearing removal.
9.1.
Put the bearing installation and removal tool (T101937) (24) on the main rotor mast (1).
9.2.
Put the plate assembly (T101901) (22) on the main rotor mast (1).
9.3.
Install two bolt assembly (T101941) (23).
9.4.
Assemble the rod set (T103260-121) (21), tie bolt (T103164) (19), rod connector (T101939) (20), tie rod spacer
(T103163) (17), washer (AN360-1016) (16), and nut (5/8-11 UNC) (15). Make sure that equal thread engagement of
the two rods is obtained in the rod connector. Assemble the opposite rods and connector in the same manner.
9.5.
Put the thrust plate (412-240-026-101) (18) on the end of the mast. Put both tie bolt (T103164) (19) in the slots of the
screw and plate set (T103166) (14) and tighten the nuts (5/8-11 UNC) (15). Tighten the large screw in the center of
the plate set to pull the bearing (26) from the mast. When the bearing is clear of the journal on the mast, remove
the tools installed in Step 9.1. through Step 9.4.. Remove the oil slinger (25), bearing (26), and liner (27) from
the main rotor mast (1).
10.
Use a hollow, cylindrical sleeve to support the outer race of the bearing (26). Put a similar sleeve on liner (27) and
press the liner off the bearing.
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-530A-B
28 OCT 2024 Page 00121-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00012-A-003-01
Figure 1. Transmission Main Rotor Mast Assembly (Sheet 1 of 6)
412-A-63-10-00-05A-530A-B
Page 00121-4 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00013-A-001-01
Figure 1. Transmission Main Rotor Mast Assembly (Sheet 2 of 6)
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-530A-B
28 OCT 2024 Page 00121-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00014-A-001-01
Figure 1. Transmission Main Rotor Mast Assembly (Sheet 3 of 6)
412-A-63-10-00-05A-530A-B
Page 00121-6 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00015-A-001-01
Figure 1. Transmission Main Rotor Mast Assembly (Sheet 4 of 6)
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-530A-B
28 OCT 2024 Page 00121-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00016-A-001-01
Figure 1. Transmission Main Rotor Mast Assembly (Sheet 5 of 6)
412-A-63-10-00-05A-530A-B
Page 00121-8 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00017-A-001-01
Figure 1. Transmission Main Rotor Mast Assembly (Sheet 6 of 6)
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-530A-B
28 OCT 2024 Page 00121-9
BHT-412-CRO
ICN-412-A-631000-B-97499-00072-A-001-01
Figure 2. Main Rotor Mast Assembly/Disassembly Tools - Tool Application (Sheet 1 of 3)
412-A-63-10-00-05A-530A-B
Page 00121-10 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00073-A-001-01
Figure 2. Main Rotor Mast Assembly/Disassembly Tools - Tool Application (Sheet 2 of 3)
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-530A-B
28 OCT 2024 Page 00121-11
BHT-412-CRO
ICN-412-A-631000-B-97499-00074-A-001-01
Figure 2. Main Rotor Mast Assembly/Disassembly Tools - Tool Application (Sheet 3 of 3)
412-A-63-10-00-05A-530A-B
Page 00121-12 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00076-A-001-01
Figure 3. Torque Tube Nut Removal - Tool Application (Sheet 1 of 1)
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-530A-B
28 OCT 2024 Page 00121-13
BHT-412-CRO
ICN-412-A-631000-B-97499-00077-A-001-01
Figure 4. Torque Tube Plug Removal - Tool Application (Sheet 1 of 1)
412-A-63-10-00-05A-530A-B
Page 00121-14 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Transmission Main Rotor Mast Assemblies (412-040-366-109 and Subsequent) - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Drycleaning solvent
MEK
Clean cloth
C-304
C-309
C-516
AR
AR
AR
Remarks
Procedure
NOTE
Mast assembly 412-040-366-109 shall be returned to Bell for rework. Mast assemblies 412-040-366-111
and -115 may be returned to Bell for rework.
1.
Remove the old sealant from the mast bearing retaining plate (14, Figure 1) with a plastic scraper and a clean
cloth (C-516) moistened with MEK (C-309).
2.
Clean all the mast assembly components with drycleaning solvent (C-304). If jet No. 8 (28) is clogged, determine the
source of the material that is clogging the jet.
3.
Dry the parts with low pressure, filtered compressed air. Do not allow the bearings to spin while drying.
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-258A-B
28 OCT 2024 Page 00122-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00012-A-003-01
Figure 1. Transmission Main Rotor Mast Assembly (Sheet 1 of 6)
412-A-63-10-00-05A-258A-B
Page 00122-2 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00013-A-001-01
Figure 1. Transmission Main Rotor Mast Assembly (Sheet 2 of 6)
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-258A-B
28 OCT 2024 Page 00122-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00014-A-001-01
Figure 1. Transmission Main Rotor Mast Assembly (Sheet 3 of 6)
412-A-63-10-00-05A-258A-B
Page 00122-4 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00015-A-001-01
Figure 1. Transmission Main Rotor Mast Assembly (Sheet 4 of 6)
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-258A-B
28 OCT 2024 Page 00122-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00016-A-001-01
Figure 1. Transmission Main Rotor Mast Assembly (Sheet 5 of 6)
412-A-63-10-00-05A-258A-B
Page 00122-6 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00017-A-001-01
Figure 1. Transmission Main Rotor Mast Assembly (Sheet 6 of 6)
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-258A-B
28 OCT 2024 Page 00122-7
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-05A-258A-B
Page 00122-8 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Transmission Main Rotor Mast Assemblies (412-040-366-109 and Subsequent) - Inspection
Procedure
NOTE
Mast assembly 412-040-366-109 shall be returned to Bell for rework. Mast assemblies 412-040-366-111
and -115 may be returned to Bell for rework.
1.
Inspect the main rotor mast in accordance with Figure 1.
IT IS MANDATORY TO REPLACE THE FOLLOWING PARTS.
2.
Figure 2INDEX NUMBER
NOMENCLATURE
6
Screw
8
Seal
15
Shim
22
Cotter Pin
24
Screw
27
Packing
30
Screw
33
Retaining Ring
37
Retaining Ring
Inspect and repair the plug (2, Figure 2), torquemeter tube assembly (3), rotor (32), plug (34), and nut (35). Refer to
Figure 3 through Figure 7.
3.
Inspect the following parts by magnetic particle inspection. Demagnetize the parts after the magnetic particle
inspection. Refer to Table 2 and the BHT-ALL-SPM, Standard Practices Manual for the procedure.
Figure 2INDEX NUMBER
NOMENCLATURE
3
Torquemeter Tube Assembly
4
Mast Assembly
7
Lock Ring
10
Mast Bearing Retention Nut
19
Bearing Liner
20
Oil Slinger
21
Bearing Race
23
Nut
32
Rotor
34
Plug
35
Nut
Table 2. Magnetic Particle Inspection
PART NUMBER
NOMENCLATURE
ITEM AND FIGURE
SET UP AND MAGNETIZATION CURRENT REQUIREMENTS
MAST ASSEMBLY (412-040-366-109, -111, AND -113)
412-040-105-101
Oil Slinger
20, Figure 2
SET UP:
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
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28 OCT 2024 Page 00123-1
BHT-412-CRO
Table 2. Magnetic Particle Inspection (continued)
Place part over a 2-inch diameter central conductor.
Current for primary diameters, magnetize at 2730 amps.
SET UP: 5 TURN COIL SHOT:
Disc-shaped portion of part: Place part in bottom of coil.
Magnetize at 3000 amps.
Rotate part 1/4 turn and repeat.
204-040-309-101
Nut
23, Figure 2
SET UP:
Place part over a 2-inch diameter central conductor.
Current for primary diameters, magnetize at 1290 amps.
Omit coil shot.
412-040-524-101
Nut
23, Figure 2
SET UP:
Place part over a 2-inch diameter central conductor.
Current for primary diameters, magnetize at 1360 amps.
Omit coil shot.
412-040-525-101
Rotor
32, Figure 2
SET UP:
Place part over a 1.5-inch diameter central conductor.
Current for primary diameters, magnetize at 1840 amps.
Optional current for secondary diameters, magnetize at 1150 amps.
Omit coil shot.
NOTES:
1. Magnetization currents provided are applicable to magnetic particle inspection apparatus using Direct Current (DC) . If an
Alternating Current (AC) apparatus is used, adjust the current as follows: AC= 0.667 x DC.
2. Ferrous parts requiring magnetic particle inspection that are not addressed in the attached material, are to be inspected in
accordance with the general procedures outlined in ASTM E1444 standard practices (BHT-ALL-SPM, Chapter 6, Standard
Practices Manual).
3. Part numbers listed apply to all successive dash numbers for that component unless otherwise specified.
4.
Fluorescent penetrant inspect the mast bearing retaining plate (14, Figure 2) in accordance with the
BHT-ALL-SPM, Standard Practices Manual. Linear and non-linear indications shall be interpreted. Linear indications
determined to be cracks and nonlinear indications determined to be corrosion pitting or pitting caused by chemical
processing that exceed the repair limits given in Figure 1 shall be cause for rejection.
412-A-63-10-00-05A-280A-B
Page 00123-2 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00078-A-001-01
Figure 1. Transmission Main Rotor Mast (412-040-366-109/-111/-113/-115/-117/-121/-127/-129) - Damage Limits (Sheet 1 of 6)
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-280A-B
28 OCT 2024 Page 00123-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00079-A-001-01
Figure 1. Transmission Main Rotor Mast (412-040-366-109/-111/-113/-115/-117/-121/-127/-129) - Damage Limits (Sheet 2 of 6)
412-A-63-10-00-05A-280A-B
Page 00123-4 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00080-A-001-01
Figure 1. Transmission Main Rotor Mast (412-040-366-109/-111/-113/-115/-117/-121/-127/-129) - Damage Limits (Sheet 3 of 6)
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-280A-B
28 OCT 2024 Page 00123-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00081-A-001-01
Figure 1. Transmission Main Rotor Mast (412-040-366-109/-111/-113/-115/-117/-121/-127/-129) - Damage Limits (Sheet 4 of 6)
412-A-63-10-00-05A-280A-B
Page 00123-6 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00082-A-001-01
Figure 1. Transmission Main Rotor Mast (412-040-366-109/-111/-113/-115/-117/-121/-127/-129) - Damage Limits (Sheet 5 of 6)
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-280A-B
28 OCT 2024 Page 00123-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00083-A-001-01
Figure 1. Transmission Main Rotor Mast (412-040-366-109/-111/-113/-115/-117/-121/-127/-129) - Damage Limits (Sheet 6 of 6)
412-A-63-10-00-05A-280A-B
Page 00123-8 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00012-A-003-01
Figure 2. Transmission Main Rotor Mast Assembly (Sheet 1 of 6)
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-280A-B
28 OCT 2024 Page 00123-9
BHT-412-CRO
ICN-412-A-631000-B-97499-00013-A-001-01
Figure 2. Transmission Main Rotor Mast Assembly (Sheet 2 of 6)
412-A-63-10-00-05A-280A-B
Page 00123-10 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00014-A-001-01
Figure 2. Transmission Main Rotor Mast Assembly (Sheet 3 of 6)
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-280A-B
28 OCT 2024 Page 00123-11
BHT-412-CRO
ICN-412-A-631000-B-97499-00015-A-001-01
Figure 2. Transmission Main Rotor Mast Assembly (Sheet 4 of 6)
412-A-63-10-00-05A-280A-B
Page 00123-12 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00016-A-001-01
Figure 2. Transmission Main Rotor Mast Assembly (Sheet 5 of 6)
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-280A-B
28 OCT 2024 Page 00123-13
BHT-412-CRO
ICN-412-A-631000-B-97499-00017-A-001-01
Figure 2. Transmission Main Rotor Mast Assembly (Sheet 6 of 6)
412-A-63-10-00-05A-280A-B
Page 00123-14 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00085-A-001-01
Figure 3. Plug (412-040-512-101) - Wear and Damage Limits (Sheet 1 of 1)
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-280A-B
28 OCT 2024 Page 00123-15
BHT-412-CRO
ICN-412-A-631000-B-97499-00244-A-001-01
Figure 4. Tube Assembly (412-040-510-103) - Wear and Damage Limits (Sheet 1 of 2)
412-A-63-10-00-05A-280A-B
Page 00123-16 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00245-A-001-01
Figure 4. Tube Assembly (412-040-510-103) - Wear and Damage Limits (Sheet 2 of 2)
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-280A-B
28 OCT 2024 Page 00123-17
BHT-412-CRO
ICN-412-A-631000-B-97499-00246-A-001-01
Figure 5. Plug (412-040-514-101) - Wear and Damage Limits (Sheet 1 of 1)
412-A-63-10-00-05A-280A-B
Page 00123-18 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00247-A-001-01
Figure 6. Nut (412-040-515-101) (S/N 36020 through 36096) - Wear and Damage Limits (Sheet 1 of 1)
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-280A-B
28 OCT 2024 Page 00123-19
BHT-412-CRO
ICN-412-A-631000-B-97499-00086-A-001-01
Figure 7. Rotor (412-040-519-101) (S/N 36020 through 36096) - Wear and Damage Limits (Sheet 1 of 2)
412-A-63-10-00-05A-280A-B
Page 00123-20 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00087-A-001-01
Figure 7. Rotor (412-040-519-101) (S/N 36020 through 36096) - Wear and Damage Limits (Sheet 2 of 2)
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-280A-B
28 OCT 2024 Page 00123-21
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-05A-280A-B
Page 00123-22 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Transmission Main Rotor Mast Assemblies (412-040-366-109 and Subsequent) - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Cadmium plating solution
Abrasive cloth or paper
Steel wool
India stone
C-108
C-406
C-411
C-464
AR
AR
AR
AR
Remarks
Procedure
NOTE
Mast assembly 412-040-366-109 shall be returned to Bell for rework. Mast assemblies 412-040-366-111
and -115 may be returned to Bell for rework.
1.
Inspect the mast for the word REWORKED on the flange E illustrated in Figure 1. If the word REWORKED is on the
flange and there is corrosion or mechanical damage on the mast that requires polishing out, reject the mast. Rework
on the mast is permitted one time only. This restriction is not applicable to the mast bearing retaining plate, liner, rotor,
plug, and nut or to superficial corrosion in areas A, F, T, and U that can be removed with steel wool (C-411).
2.
Dress out small burrs, nicks, and scratches on the splines O (Figure 1) with a fine india stone (C-464).
3.
Polish out mechanical and corrosion damage on the mast in areas other than areas A, F, T, and U. Also, polish out
damage on the bearing retaining plate. Use fine to medium abrasive cloth or paper (C-406) or a fine india stone
(C-464). If damage after a complete cleanup exceeds the limits of Figure 1, the mast is not repairable. Final polish
repair the area to a surface roughness of 32 RMS or better.
NOTE
If corrosion must be polished out on the mast inside diameter, comply with Note 4 in Figure 1.
4.
Polish out superficial corrosion damage in areas A, F, T, and U (Figure 1) with steel wool (C-411) or with a wire
brush only. Removal of superficial corrosion from areas A, F, T, and/or area U does not require marking the word
REWORKED on flange E.
5.
If damage was polished out on areas of the mast other than areas A, F, T, and U, or the mast bearing retaining plate,
mark the word REWORKED on flange E with vibrating stylus.
6.
Touch up rework areas where cadmium plating was removed as follows:
6.1.
If field repair is being accomplished, do not apply brush cadmium plating on the inside diameter of the mast beyond
the 6.0-inches (152-mm) limits noted at step 4 in Figure 1.
6.2.
Use only the brush cadmium plating procedures noted in the BHT-ALL-SPM, Standard Practices Manual.
6.3.
Apply cadmium plating solution (C-108) only in the areas indicated in Figure 2 (BHT-ALL-SPM, Standard Practices
Manual).
7.
Replace missing or illegible nameplate (BHT-ALL-SPM, Standard Practices Manual).
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-685A-B
31 MAY 2023 Page 00124-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00078-A-001-01
Figure 1. Transmission Main Rotor Mast (412-040-366-109/-111/-113/-115/-117/-121/-127/-129) - Damage Limits (Sheet 1 of 6)
412-A-63-10-00-05A-685A-B
Page 00124-2 31 MAY 2023
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00079-A-001-01
Figure 1. Transmission Main Rotor Mast (412-040-366-109/-111/-113/-115/-117/-121/-127/-129) - Damage Limits (Sheet 2 of 6)
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-685A-B
31 MAY 2023 Page 00124-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00080-A-001-01
Figure 1. Transmission Main Rotor Mast (412-040-366-109/-111/-113/-115/-117/-121/-127/-129) - Damage Limits (Sheet 3 of 6)
412-A-63-10-00-05A-685A-B
Page 00124-4 31 MAY 2023
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00081-A-001-01
Figure 1. Transmission Main Rotor Mast (412-040-366-109/-111/-113/-115/-117/-121/-127/-129) - Damage Limits (Sheet 4 of 6)
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-685A-B
31 MAY 2023 Page 00124-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00082-A-001-01
Figure 1. Transmission Main Rotor Mast (412-040-366-109/-111/-113/-115/-117/-121/-127/-129) - Damage Limits (Sheet 5 of 6)
412-A-63-10-00-05A-685A-B
Page 00124-6 31 MAY 2023
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00083-A-001-01
Figure 1. Transmission Main Rotor Mast (412-040-366-109/-111/-113/-115/-117/-121/-127/-129) - Damage Limits (Sheet 6 of 6)
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-685A-B
31 MAY 2023 Page 00124-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00088-A-001-01
Figure 2. Transmission Main Rotor Mast - Cadmium Plating Areas (Sheet 1 of 1)
412-A-63-10-00-05A-685A-B
Page 00124-8 31 MAY 2023
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Transmission Main Rotor Mast Assemblies (412-040-366-109 and Subsequent) - Assembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Wrench Assembly
412-240-003-101
412-240-004-101
Socket
Thrust Plate
412-240-026-101
Wrench Assembly
412-240-031-101
Power Wrench Kit
T100965
Anchor Plate
T100968
Plate Assembly
T101901
Bearing Installation and Removal Tool T101937
Bolt Assembly
T101941
T103163
Tie Rod Spacer
T103165
Splined Adapter
T103166
Screw and Plate Set
T103178
Socket Wrench
T103192
Sleeve Protector
T103260-121
Rod Set
Qty
Remarks
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Grease
Assembly fluid
Grease
Epoxy polyamide primer
Polyurethane coating
Epoxy primer coating
C-001
C-024
C-172
C-204
C-245
C-246
AR
AR
AR
AR
AR
AR
Sealant
Aliphatic naphtha
Sealant
MEK
Adhesive
Denatured alcohol
Sealant
Lockwire
Masking tape
Anti-seize thread compound
Clean cloth
C-251
C-305
C-308
C-309
C-317
C-326
C-328
C-405
C-426
C-452
C-516
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
AR
Remarks
As an alternate, use epoxy polyamide primer
(C-204)
Procedure
DO NOT TOUCH PORTION OF MAST THAT IS NORMALLY INSIDE TRANSMISSION WITH BARE
HANDS.
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-710A-B
28 OCT 2024 Page 00125-1
BHT-412-CRO
WHEN LIFTING MAST WITH HOIST, USE MAST NUT 204-010-481-001 AND CLEVIS ASSEMBLY
204-011-178-001. DO NOT USE CAP ASSEMBLY THAT IS USED TO SECURE MAIN ROTOR HUB
TO MAST.
NOTE
Mast assembly 412-040-366-109 shall be returned to Bell for rework. Mast assemblies 412-040-366-111
and -115 may be returned to Bell for rework.
1.
Put a layer of protective paper on the mast and attach with masking tape (C-426) to prevent scratching the mast
during the assembly procedures.
2.
Before you install the bearing (17, Figure 1 ) and the mast bearing retention nut (10), apply a coat of epoxy primer
coating (C-246) to the annular groove only. Do not apply primer to the bearing journal or to the threaded area. Let dry.
3.
Apply grease (C-172) to the mast bearing journal and to the first three threads of the threaded area. Fill the annular
groove with grease.
4.
Install the bearing on the mast as follows:
4.1.
Put the bearing (17) with the V-marks (16) on the bearing inner races aligned and the apex pointing toward the top of
the mast. Align the V-marks (18) on the bearing outer races with the apex pointing toward the bottom of the mast.
4.2.
Put a hollow cylindrical metal sleeve of the correct dimension to touch the bearing outer race on the bearings (17)
and push the bearing into the bearing liner (19). Turn the bearing inner race to check for freedom of operation
during the seating procedure.
4.3.
Put a shim (15) of sufficient thickness to make a clearance between the flange of the bearing liner (19) and the
flange of the mast bearing retainer plate (14).
4.4.
Install the mast bearing retainer plate (14) on the mast assembly (4) with care to prevent damage on the seal on the
mast splines. Attach the bearing liner with four new screws (24).
4.5.
Measure and record the clearance between the bearing liner (19) and the retainer plate (14). To get the correct shim
(15) thickness, subtract the previously recorded dimension from the shim installed in Step 4.3. and add 0.001 to
0.003 inch (0.03 to 0.08 mm) to the total shim (15) thickness. This will result in a 0.001 to 0.003 inch (0.03 to 0.08
mm) pinch on the bearing (17).
4.6.
Remove four screws (24) and disconnect the bearing liner (19) from the mast bearing retaining plate (14).
NOTE
Refer to Figure 2, section E-E, for the sectional view of the bearings, oil slinger, and liner installed on the
mast.
4.7.
Put the bearing installation and removal tool (T101937) (24, Figure 2) on the main rotor mast (1).
4.8.
Put the oil slinger (25), bearings (26), and liner (27) on the main rotor mast (1).
4.9.
Put the plate assembly (T101901) (22) on the mast and install two bolt assembly (T101941) (23).
4.10.
Put the thrust plate (412-240-026-101) (18), screw and plate set (T103166) (14), two rod set (T103260-121) (21),
two tie rod spacer (T103163) (17), two washers (AN960-1016) (16), and two nuts (5/8-11 UNC) (15) on the mast.
Tighten the nuts.
4.11.
Carefully tighten the large screw in the screw and plate set (T103166) (14) to pull the bearing into its position on the
mast. When the bearing is fully installed against the shoulder on the mast, remove the tools installed in Step 4.7.
through Step 4.10..
5.
Make sure that after the bearing (17, Figure 1) installation, the annular groove is filled with grease (C-172). Make
sure that the first three threads of the threaded area have grease. Remove unwanted grease from the lower side
area of the bearing.
412-A-63-10-00-05A-710A-B
Page 00125-2 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
NOTE
Depending on the helicopter configuration, a mast bearing retention nut (2,Figure 2) 412-040-104-101 or
-103 may be applicable for installation. The primary difference between the mast bearing retention nuts
412-040-104-101 and -103 is that the threads of the -103 retention nut are coated with solid film lubricant.
Before the installation of a retention nut -103, make sure the threads have a coating of solid film lubricant.
If the solid film lubricant coating is damaged or missing, refer to the BHT-ALL-SPM, Standard Practices
Manual for application procedures. The application of solid film lubricant is directly related to the nut -103
torque value specified in the following assembly instructions.
6.
Install the mast bearing retention nut (2) as follows:
NOTE
Refer to Figure 2, Detail B for the view of the installed bearing retention nut removal/installation tools.
6.1.
Make sure that the mast bearing retention nut (2) has a wear sleeve bonded to the nut before installation. Thread the
nut onto the mast with the splined end of the nut adjacent to the bearing.
6.2.
If the wear sleeve is damaged, install a new wear sleeve on the mast bearing retention nut (2) as follows:
6.2.1.
Prevent the bearing from contamination and carefully remove the wear sleeve.
6.2.2.
Remove the adhesive from the mast bearing retention nut (2) and clean with a clean cloth (C-516) moistened
with MEK (C-309).
6.2.3.
Apply adhesive (C-317) to the outside diameter of the mast bearing retention nut (2) and install a new wear sleeve.
6.2.4.
Clean off excess adhesive, as required.
6.3.
Put the sleeve protector (T103192) (7) on the mast bearing retention nut (2).
6.4.
Put the socket wrench (T103178) (6) on the mast bearing retention nut (2).
6.5.
Put the power wrench kit (T100965) (5) on the mast with the lugs and thumb screws (11) toward the top of the mast.
6.6.
Put the anchor plate (T100968) (4) on the mast. Engage the anchor plate on the lugs of the power wrench kit
(T100965) (5). Tighten the two thumb screws (11).
6.7.
Put the splined adapter (T103165) (3) to engage the splines on the mast with the splines on the anchor plate
(T100968) (4).Make sure that the splines are fully engaged.
6.8.
For the mast bearing retention nut (2) 412-040-104-101, examine the data plate on the power wrench kit (T100965)
(5) and find what torque should be applied with the torque wrench (13) to the nut .
6.9.
For the mast bearing retention nut (2) 412-040-104-103, examine the data plate on the power wrench kit (T100965)
(5) and find what torque should be applied with the torque wrench (13) to the nut .
6.10.
Put the steel bar (12) in the anchor plate (T100968) (4).
6.11.
Put the torque wrench (13) on the power wrench kit (T100965) (5).
6.12.
For the mast bearing retention nut (2) 412-040-104-101, make sure that the splines on the tools, mast, and nut are
fully engaged and torque the nut to the lowest torque value
with the torque wrench (13). Turn the outer race
of the bearing to examine the freedom of operation.
6.13.
For the mast bearing retention nut (2) 412-040-104-103, make sure that the splines on the tools, mast, and nut are
fully engaged and torque the nut to the lowest torque value
with the torque wrench (13). Turn the outer race
of the bearing to examine the freedom of operation.
6.14.
Remove the tools installed in the preceding steps.
7.
Put the lock ring (7, Figure 1) on the mast bearing retention nut (10) and check whether the holes for the screws (6)
are aligned. If the holes are not aligned, rotate the lock ring to different splines on the mast. If the holes for all four
screws are still not accessible, reinstall the tools and tighten the mast bearing retention nut (2, Figure 2). Repeat, as
required, until the four screws (6, Figure 1) can be installed, but do not exceed the torque limits noted in Step 6.8.
and Step 6.9.. Do not install the lock ring at this time.
8.
After the holes are aligned for the four screws (6), install the tools as outlined in Step 6.3. through Step 6.11.. These
tools will be used to hold the mast during the installation of the bearing race (21) and the nut (23 or 39).
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-710A-B
28 OCT 2024 Page 00125-3
BHT-412-CRO
9.
Install the bearing race (21) and the nut (23 or 39) as follows:
NOTE
The bearing race retention nut has left-hand threads.
9.1.
Put the bearing race (21) on the mast assembly (4).
9.2.
Apply anti-seize thread compound (C-452) to the threads of the mast and nut (23 or 39). Thread the nut on the mast.
9.3.
Put the wrench (T101456 or 412-240-027-101) (9, Figure 2) and torque the torque wrench (10) on the nut. Torque the
nut to the lowest torque value . Remove the wrenches and determine whether the two cotter pins (22, Figure 1), or
two rivets (40) can be installed. If necessary, apply more torque to the nut, but do not exceed the high side limit.
9.4.
For the mast assemlies 412-040-366-111 and -115, install the two new cotter pins (22) and bend as described in
Figure 1 (Detail B, Note 3).
9.5.
Remove the tools that were installed in Step 8..
NOTE
The mast assembly 412-040-366-109 must be returned to Bell for calibration of the torquemeter tube
assembly whenever the mast assembly has had the torquemeter tube or mast lower rotor disassembled
or repositioned.
10.
For the mast assemblies 412-040-366-111 and -115, install the rotor (32) as follows:
10.1.
Apply adhesive (C-317) to the faying surfaces of the rotor (32) and mast assembly (4).
10.2.
Install the rotor (32) in the mast assembly (4). Wipe off unwanted adhesive and install the retaining ring (33).
10.3.
Install the plug (34) and the nut (35).
10.4.
Attach the wrench assembly (412-240-003-101) to the rotor (32). Install the socket (412-240-004-101) through the
wrench assembly. Torque the nut (35) within one hour of application of adhesive (C-317) for installation of rotor.
10.5.
Line up the tabs on the lock ring (36) with the notches in the nut (35) and install the lock ring.
10.6.
Install the new retaining ring (37).
10.7.
If the mast torque tube is to be installed at this time, refer to the BHT-412-MM-6 for installation and alignment
instructions.
11.
For the mast assemblies 412-040-366-113, -117, -121, -123, -127, and -129, install the rotor (4, Figure 3) as follows:
11.1.
Install the rotor (4) on the mast assembly (1) with any two diametrically opposed tabs centered on the spotfaced
mast pilot holes within 0.030 inch (76 mm).
11.2.
With the rotor (4) tightly installed against the shoulder, line drill the mast and rotor tabs at the two spotfaced pilot
holes, except hole for rivet to be 0.129 to 0.130 inch (3.28 to 3.30 mm) diameter.
11.3.
Edge break holes after reaming to remove burrs, maximum edge break 0.003 inch (0.08 mm).
11.4.
Install the two rivets (3) with the manufactured head outboard in one of the two diametrically opposed mast holes
positioned in the slots of the fully torqued nut (2).
11.5.
After rivet installation, use wrench assembly (412-240-003-101) and apply a test torque of 100 inch-pounds (11.30
Nm) in the clockwise and counterclockwise directions to the rotor (4). No relative movement between the mast
and rotor is allowed.
11.6.
If the mast torque tube is to be installed at this time, refer to the BHT-412-MM-6 for installation and alignment
instructions.
12.
Apply sealant (C-328) to the mast bearing retaining plate (14, Figure 1) and the seal (8) as follows:
12.1.
Install the new seal (8) in the mast bearing retaining plate (14), as shown in Detail A.
12.2.
Refer to Figure 1 for the definition of the area where the sealant is to be applied.
12.3.
Clean the surfaces where the sealant is to be applied with a clean cloth (C-516) moistened with MEK (C-309). Wipe
dry with a clean cloth (C-516) before the solvent evaporates.
412-A-63-10-00-05A-710A-B
Page 00125-4 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
12.4.
Mix sealant (C-328) in accordance with the manufacturer’s instructions on the container, or mix 100 parts by weight of
base material to 12 parts by weight of accelerator. Mix fully. The pot life of mixed sealant is 2 hours. Tack-free time
after application is 12 to 24 hours.
12.5.
Locate four 0.125 inch (3.18 mm) drain holes in the mast bearing retaining plate (14). Make sure that the sealant
does not cause a blockage to these four holes. Apply sealant (C-328) to the area indicated in Figure 1.
NOTE
Do not fill grease in the space between the seal lips.
13.
Lightly lubricate the new seal (8) lips and mating sleeve outside diameter with grease (C-001).
14.
Clean the mating surfaces of the bearing liner (19) and the mast bearing retaining plate (14) with aliphatic naphtha
(C-305) or denatured alcohol (C-326).
15.
Apply a thin layer of sealant (C-328) to the lower surface of the mast bearing retaining plate (14) flange, as shown in
Figure 1 Detail A.
16.
Put the shim (15) in position on top of the bearing (17).
NOTE
The Step 17. is applicable to helicopters S/N 36495 through 36999, S/N 37002 through 37999, and mast
assemblies Post TB 412-08-218.
Applicable: SN: 36495-36999 or 37002-37999 or TB 412-08-218: Post:
17.
Install the packing (47). A light coat of assembly fluid (C-024) may be used to crrectly position the packing. Make
sure the assembly fluid application contacts only the packing, bearing liner (19) surfaces, and mast bearing retaining
plate (14).
18.
Put the mast bearing retaining plate (14) in position on the bearing liner (19).
19.
Attach the bearing liner (19) to the mast bearing retaining plate (14) with four screws (24). Make sure that the seating
of the seal (8), packing (47), as applicable, and shims (15) is correct.
IF MAST ASSEMBLY IS NOT TO BE FULLY INSTALLED IN A TRANSMISSION WITHIN 30 MINUTES
OF SEALANT APPLICATION, Step 20. MUST BE DONE.
20.
Install the bolts (41), washers (42, 43, and 44), and nuts (45) to clamp the bearing liner (19) to the mast bearing
retaining plate (14), as shown in Figure 1, Detail A. Torque the nuts 100 to 140 inch-pounds (11.3 to 15.8 Nm).
Tighten the screws (24), again.
NOTE
Store the mast assembly (4) until it is required. If the mast assembly is being installed in the transmission,
then Step 21. must be completed within 30 minutes of sealant (C-308) application.
21.
Immediately before installing the main rotor mast assembly (4) into the transmission assembly (BHT-412-MM-6),
clean the mating surfaces of the bearing liner (19) flange and the top of the transmission case assembly (46) with
aliphatic naphtha (C-305) or denatured alcohol (C-326). Apply a thin coating of sealant (C-308) to the transmission
case assembly (46, Detail F).
22.
Put the jet No. 8 (28) in the mast bearing retaining plate (14) with the new packing (27) and install the screw (30).
Install the cap (29).
23.
Clean the lock ring (7) and apply a light coat of sealant (C-251) to the nut side and a bead of sealant on the thread
adjacent to the nut face.
24.
Put the lock ring (7) on the mast and install the four new screws (6). Safety the four screws (6) with lockwire (C-405).
25.
Fill the four holes of the lock ring (7) with sealant (C-251).
26.
Apply a bead of sealant (C-251) to cover the exposed threads and the lock ring screws (6) up to the edge of the
lock ring (7). Apply sealant (C-251) to make a slope and make sure that the water goes away from the lock ring (7),
as shown in Figure 1, Detail A.
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-710A-B
28 OCT 2024 Page 00125-5
BHT-412-CRO
27.
Apply one layer of epoxy primer coating (C-246) and one layer of polyurethane coating (C-245) from the outboard
edge of the lock ring (7) up to the mast assembly (4) (Detail A).
412-A-63-10-00-05A-710A-B
Page 00125-6 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00012-A-003-01
Figure 1. Transmission Main Rotor Mast Assembly (Sheet 1 of 6)
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-710A-B
28 OCT 2024 Page 00125-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00013-A-001-01
Figure 1. Transmission Main Rotor Mast Assembly (Sheet 2 of 6)
412-A-63-10-00-05A-710A-B
Page 00125-8 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00014-A-001-01
Figure 1. Transmission Main Rotor Mast Assembly (Sheet 3 of 6)
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-710A-B
28 OCT 2024 Page 00125-9
BHT-412-CRO
ICN-412-A-631000-B-97499-00015-A-001-01
Figure 1. Transmission Main Rotor Mast Assembly (Sheet 4 of 6)
412-A-63-10-00-05A-710A-B
Page 00125-10 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00016-A-001-01
Figure 1. Transmission Main Rotor Mast Assembly (Sheet 5 of 6)
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-710A-B
28 OCT 2024 Page 00125-11
BHT-412-CRO
ICN-412-A-631000-B-97499-00017-A-001-01
Figure 1. Transmission Main Rotor Mast Assembly (Sheet 6 of 6)
412-A-63-10-00-05A-710A-B
Page 00125-12 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00072-A-001-01
Figure 2. Transmission Main Rotor Mast Assembly/Disassembly Tool - Tool Application (Sheet 1 of 3)
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-710A-B
28 OCT 2024 Page 00125-13
BHT-412-CRO
ICN-412-A-631000-B-97499-00073-A-001-01
Figure 2. Transmission Main Rotor Mast Assembly/Disassembly Tool - Tool Application (Sheet 2 of 3)
412-A-63-10-00-05A-710A-B
Page 00125-14 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00074-A-001-01
Figure 2. Transmission Main Rotor Mast Assembly/Disassembly Tool - Tool Application (Sheet 3 of 3)
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-05A-710A-B
28 OCT 2024 Page 00125-15
BHT-412-CRO
ICN-412-A-631000-B-97499-00089-A-001-01
Figure 3. Mast Assembly (412-040-366-113, -117, -121, -123, -127, and , -129) - Rotor Installation (Sheet 1 of 1)
412-A-63-10-00-05A-710A-B
Page 00125-16 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999
or 46400-46499 or 412-570-001-103: Installed or
BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Transmission (412-040-002, 412-040-004, 412-040-007 and 412-040-802) - General
Before you disassemble, examine the transmission and the transmission records for the sign of accident or
incident outside the realm of correct usage. If there is a sign of the accident or incident, follow the instructions
in 412-A-63-10-00-06A-280A-B / 00129.
Refer to the Mandatory Airworthiness Schedule in the applicable Maintenance Manual and identify if the transmission
components have been assigned mandatory maximum hours life before retirement from service. If any transmission
components have been assigned maximum hours life, identify these components for retirement.
Applicable to: ALL
412-A-63-10-00-06A-042A-B
ECCN EAR99
14 NOV 2023 Page 00126-1
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-06A-042A-B
Applicable to: ALL
Page 00126-2 14 NOV 2023
ECCN EAR99
BHT-412-CRO
Transmission - Disassembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Backlash Tool Set
Mount Assembly
Adapter
Maintenance Stand
Maintenance Transportation Stand
Adapter
Jackscrew Set
Screw Set
Jackscrew Set
Cover and Lift Plate Assembly
412-240-006-101
SWE 13832-21
SWE 13852-40
SWE 13855B
SWE 13875
SWE 13875-60
T100929
T101308
T101338
T103211-101
1
1
1
1
1
1
1
1
1
1
Remarks
Procedure
1.
If a conditional inspection is required, accomplish the conditional inspections, such as check for binding of internal
parts, prior to disassembly (412-A-63-10-00-06A-280A-B / 00129 and 412-A-63-10-00-06A-284A-B / 00130).
NOTE
If the transmission is being disassembled for replacement of parts, instead of overhaul, disassemble only
to the extent necessary to replace the parts.
2.
If not previously accomplished, remove the main rotor mast (BHT-412-MM).
3.
Install the cover and lift plate assembly (T103211-101) on the transmission.
NOTE
The transmission assembly/overhaul stand (Figure 1) is the preferred stand to support the transmission
during maintenance procedures, which include removal/installation of tail rotor drive and sump assembly;
however, it is possible to use the transmission maintenance/ transportation stand Figure 2.
4.
Assemble the stand that will be used to support the transmission (Figure 1 and Figure 2).
5.
If the transportation stand illustrated in Figure 2 is to be used, remove the accessory and tail rotor drive and sump
assembly prior to removal of the top case. Refer to Step 67. for the removal procedure.
6.
Hoist the transmission into position and secure the transmission in the stand assembled in Step 4..
DO NOT USE ANY METALLIC DRIFTS FOR DISASSEMBLY OR ASSEMBLY OF COMPONENTS,
SUCH AS BEARINGS, RACEWAYS, SLEEVES, ETC.
7.
Remove the transmission electrical cable as follows (Figure 3):
7.1.
Disconnect the electrical terminal and nipple (14) from the upper mast electrical chip detector (15).
7.2.
Remove the electrical terminal and nipple (19) from the planetary electrical chip detector (18).
7.3.
Remove the electrical connector (17) from the rotor tachometer generator (16).
7.4.
Remove the electrical terminal and nipple (13) from the oil thermostatic switch (12).
7.5.
Remove the electrical connector (5) from the oil pressure switch (4).
7.6.
Remove the electrical connector (3) from the oil pressure transmitter (2).
7.7.
Remove the electrical connector (7) from the oil temperature transmitter (8).
Applicable to: ALL
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ECCN EAR99
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BHT-412-CRO
7.8.
Remove the electrical terminal and nipple (11) from the sump electrical chip detector (10).
NOTE
Transmissions with oil filters have three ground wires. Transmissions with full flow debris monitors have
four ground wires.
7.9.
Remove the four wires for the rotor brake (20) from the rotor brake, if installed.
7.10.
Remove the ground wires (23).
NOTE
For transmissions with a full flow debris monitor installed, perform Step 7.11..
7.11.
Remove the electrical terminal and nipple (11B) from the full flow debris monitor (11A).
7.12.
Remove the clamps (21) from the transmission electrical cable assembly (22).
7.13.
Remove the transmission electrical cable assembly (22) from the transmission (1).
8.
Remove the neck and scupper assembly (1, Figure 4) as follows:
8.1.
Remove the screws (16), washers (13), nuts (12), and clamps (15). Discard the clamps.
8.2.
Loosen the nuts (10) and remove the hose assembly (11).
8.3.
Loosen the nut (21) and remove the elbow and packing (19). Discard the packing.
8.4.
Remove the screw (18), washer (28), and nut (29) from the clamp (14) and bracket (8). Discard the clamp.
8.5.
Loosen the nut (20) and remove the tube (17) from the union. Remove the union and packing (25). Discard
the packing.
8.6.
Loosen the nuts (6) and remove the tube (7).
8.7.
Loosen the nut (4) and remove the elbow (5), nut, and packing (3). Discard the packing.
8.8.
Remove the four nuts (22) and washers (23 and 24).
8.9.
Remove the neck and scupper assembly (1) from the neck and scupper support bracket (2).
NOTE
Remove the neck and scupper support bracket (2) with the ring gear in Step 54. of this procedures.
9.
Remove the filler oil cap adapter (9) as follows:
9.1.
Remove the tube (7) from the filler oil cap adapter (9) and the elbow (5).
NOTE
In order to lock the filler oil cap adapter (9) from the inside, fabricate a workaid that will simulate a filler
cap assembly,
9.2.
Remove the filler oil cap adapter (9).
9.3.
Gain access to the filler adapter (30) on the main support case.
9.4.
Apply heat to the filler adapter (30). Heat should not exceed 200°F (93°C).
9.5.
Unscrew the filler adapter (30) from the main support case with the work aid or equivalent.
10.
Remove the plug (1, Figure 5) and the packing (2). Discard the packing.
11.
Loosen the nuts (22) and remove the tube (4).
12.
Loosen the nut (6).
13.
Remove the elbow and packing (5) and the nut (6). Discard the packing.
14.
Remove the banjo bolt (20) and the elbow and two packings (19). Discard the packings.
412-A-63-10-00-06A-530A-B
Applicable to: ALL
Page 00127-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
15.
Remove the oil pressure transmitter (5, Figure 6) and the packing (2). Discard the packing.
16.
Remove the oil pressure switch (7) and the packing (6). Discard the packing.
17.
Remove the union (4) and the packing (3). Discard the packing.
18.
Loosen the nuts (21, Figure 5) and remove the tube (7).
19.
Loosen the nut (9).
20.
Remove the elbow (8), packing (10), and nut (9). Discard the packing.
21.
Loosen the nuts (23) and remove the tube (18).
22.
Loosen the nut (16).
23.
Remove the elbow (17) and the packing (15). Discard the packing.
24.
Remove the screw (6, Figure 7), gasket (4) and the thin steel washer (5). Remove the screw (7) and the oil jet No. 6
(8). Remove and discard the packings (1, 2, and 3) and the gasket.
25.
Remove the screw (15), gasket (13), and thin steel washer (14). Remove the bolt (16), thin steel washer (17), bracket
(18), and the oil jet No. 3 (12). Remove and discard the packings (9, 10, and 11) and the gasket.
26.
Remove the screw (24), gasket (22), and thin steel washer (23). Remove the screw (25) and the oil jet No. 2 (21).
Remove and discard the packings (19 and 20) and the gasket.
27.
Remove the screw (27), thin steel washer (28), and gasket (29). Remove the screw (26) and the oil jet No. 1 (30).
Remove and discard the packings (31 and 32) and the gasket.
28.
Remove the screw (33), thin steel washer (34), and gasket (35). Remove the screw (39) and the oil jet No. 5 (36).
Remove and discard the packings (37 and 38) and the gasket.
29.
Loosen the nut (51).
30.
Remove the elbow (52), nut (51), and packing (50). Discard the packing.
31.
Remove the screw (49).
32.
Remove the auxiliary oil jet (48) and the packing (47). Discard the packing.
33.
Loosen the nut (45).
34.
Remove the elbow (46), nut (45), and packing (44). Discard the packing.
35.
Remove the screw (43).
36.
Remove the auxiliary oil jet (42) and the packing (41). Discard the packing.
37.
Remove the pressure regulating valve (10, Figure 6) and the packing (9). Discard the packing.
38.
Remove the thermostatic switch (12) and the packing (11). Discard the packing.
39.
Remove the thermobulb (9, Figure 8) and the packing (8). Discard the packing.
40.
Remove the screw (20) and the steel washer (19). Remove the screw (15), seal (16), and the oil jet No. 7 (13).
Discard the seal.
41.
Remove and discard the packings (17 and 18).
42.
Remove the bolt (10), washer (11), and bracket (12).
43.
Remove the oil temperature manifold (14).
44.
Remove the gasket (5), and packings (6 and 7). Discard the gasket and the packings.
45.
Remove the oil transfer tube (3) and the packings (2 and 4). Discard the packings.
46.
Remove the union (27) and the packing (28). Discard the packing.
Applicable to: ALL
412-A-63-10-00-06A-530A-B
ECCN EAR99
28 OCT 2024 Page 00127-3
BHT-412-CRO
47.
Remove the nut (26), aluminum washer (24), and steel washer (25).
48.
Remove the oil pressure manifold (23) and the spacer (22) from the transmission (1).
49.
Remove the top case (20, Figure 9) as follows:
49.1.
Remove the upper mast electrical chip detector (1).
49.2.
Remove and discard the packing (2).
49.3.
Cut the sealant at the mating flange of the top case (20) and the ring gear (11) with a plastic scraper.
49.4.
Remove the bolt (3), washers (4 and 7), nut (8), and bracket (5).
49.5.
Remove the 15 bolts (21), washers (10, 15, and 16), and nuts (9).
49.6.
Remove the three screws (19) and the aluminum washers (18).
49.7.
Install three jackscrew set (T100929) in the holes where the screws (19) were removed. Equally turn the jackscrews
clockwise to pull the top case (20) from the ring gear (11).
49.8.
Remove the top case (20) and remove the jackscrews from the case.
49.9.
Remove the oil transfer tube (13) and the packings (12 and 14). Discard the packings.
49.10.
Remove and discard the packing (17).
NOTE
Perform a backlash check, if desired.
50.
Remove the rotor brake drive quill (13, Figure 10) as follows:
WHEN JACKSCREWS ARE USED TO REMOVE QUILLS, MAKE SURE THAT ALL SEALANT IS
REMOVED FROM THREADED HOLES PRIOR TO INSTALLATION OF JACKSCREWS.
50.1.
If installed, remove the brake assembly (3A) and the disc (3) (BHT-412-MM-6, Chapter 63).
50.2.
Remove the bolts (14) and the washers (15 and 16).
50.3.
With the screw set (T101308), remove the rotor brake drive quill (13) from the transmission (1).
50.4.
Remove and discard the packing (17).
51.
Remove the hydraulic pump drive quill (4) as follows:
51.1.
If installed, remove the nuts (11), washers (10), cover (9), and gasket (8). Discard the gasket.
51.2.
Cut the sealant around the hydraulic pump drive quill (4) with a plastic scraper and remove sealant from the
jackscrew holes.
51.3.
Remove the bolts (7) and the washers (5 and 6).
51.4.
Install three screw set (T101308) in the threaded holes in the hydraulic pump drive quill (4). Equally turn the
jackscrews clockwise to pull the quill from the transmission (1).
51.5.
Remove and discard the packing (12).
52.
Remove the main input quill (6, Figure 11) as follows:
52.1.
Loosen the nut (24) and remove the tube (seal drain) (21).
52.2.
Remove the union (22) and the packing (23). Discard the packing.
52.3.
Remove the plug (15) and the packing (16). Discard the packing.
52.4.
Remove the nut (11), aluminum washer (9), and clip (10).
412-A-63-10-00-06A-530A-B
Applicable to: ALL
Page 00127-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
52.5.
Remove the six nuts (12) and the washers (13 and 14).
52.6.
Cut the sealant around the edge of the quill where it contacts the transmission case with a plastic scraper.
52.7.
Remove the three screws (8) and the washers (7).
52.8.
Install three screw set (T101308) in the holes where the screws (8) were removed.
52.9.
Equally turn the jackscrews clockwise and carefully pull the quill from the transmission case.
52.10.
Remove the three jackscrews and immediately install the three screws (8) and the washers (7) to secure the cap to
the quill sleeve. Tighten the screws.
52.11.
Remove the oil transfer tube (19).
52.12.
Remove and discard the packings (18 and 20).
52.13.
Remove and discard the packings (4 and 5).
53.
Remove the upper planetary (2, Figure 12) as follows:
53.1.
Remove the upper planetary (2), mast driving adapter (3), extension (4), upper bearing (5), and liner (outer) (6) out
of the ring gear (15) as a unit.
53.2.
Remove the retaining ring (1) and separate the mast driving adapter (3), upper bearing (5), and liner (outer) (6).
53.3.
Remove the upper sun gear (7) and the oil deflector (9) as a unit.
53.4.
Remove the retaining ring (8) and the oil deflector (9) from the upper sun gear (7).
NOTE
The lower planetary (10) and the remaining components will be removed after the ring gear is removed.
54.
Remove the ring gear (5, Figure 13) and the three jet housings as follows:
54.1.
Remove the bolts (1), washers (2, 3, 23, and 24), and nuts (22).
54.2.
Remove the neck and scupper support bracket (4).
54.3.
Remove the bolt (6), washers (18, 19, 44), nut (17), and bracket (7).
54.4.
Remove the bolts (8), washers (9, 14, and 15), and nuts (16).
54.5.
Cut the sealant between the ring gear (5) and the main case assembly (13) with a plastic scraper.
54.6.
Remove the ring gear (5) from main case assembly (13). If necessary, tap on the ring gear lightly with a plastic or a
rawhide mallet to separate it from main case. Remove the ring gear and packing (10). Discard the packing.
54.7.
Remove and discard the cotter pins (25).
54.8.
Remove the bolts (28), washers (27, 27A, 29, 30, and 31), and nuts (26).
54.9.
Remove the oil jet housing (32) and the gasket (33). Discard the gasket.
54.10.
Remove and discard the cotter pins (35).
54.11.
Remove the bolts (43), washers (37, 37A, 40, 41, and 42), and nuts (36).
54.12.
Remove the oil jet housing (39) and the gasket (38). Discard the gasket.
54.13.
Remove the oil jet housing (34) in same manner outlined for the oil jet housing (39).
55.
Remove the lower planetary (10, Figure 12) from the transmission.
56.
Remove the liners (11 and 13) and the lower bearing (12). Separate the liners and the bearing.
57.
Remove the lower sun gear (14) from the main input gear quill (16).
58.
Remove the main input gear quill (1, Figure 14) as follows:
Applicable to: ALL
412-A-63-10-00-06A-530A-B
ECCN EAR99
28 OCT 2024 Page 00127-5
BHT-412-CRO
58.1.
Make sure that the oil temperature manifold (14, Figure 8) is removed.
58.2.
Remove the planetary electric chip detector (20, Figure 14) and the packing (21). Discard the packing.
58.3.
Cut the sealant between the main input gear quill (1) and the main case (3) with a plastic scraper.
NOTE
For the transmission 412-040-004 use the screw set (T101308).
58.4.
Install the jackscrew set (T100929) or the screw set (T101308) in three threaded holes in the main input gear quill (1)
and tighten evenly to separate the gear quill from the case (3).
58.5.
Remove the main input gear quill (1) and the packing (2) from the main case (3). Discard the packing.
59.
Remove the main case (3) as follows:
59.1.
Remove the nut (22), bracket (24), and washer (23).
59.2.
Remove the twelve nuts (4) and the washers (5 and 6).
59.3.
Remove the eight nuts (28), and the washers (26 and 27).
59.4.
Cut the sealant between the main case (3) and the support case (18) with a plastic scraper.
59.5.
Install the screw set (T101308) and tighten evenly to separate the main case (3) from the support case (18).
59.6.
Remove the main case (3) and the packing (25). Discard the packing.
60.
Inspect the four dowel pins (19) for evidence of shearing. If more than one dowel pin is sheared and torsional
overload is indicated the entire transmission is non-airworthy and nonrepairable.
61.
Remove the cotter pins (12), six nuts (13), and washer (14). Discard the cotter pins.
62.
Remove the offset accessory drive quill (15) with the jackscrew set (T101338).
63.
If not previously accomplished, remove the tail rotor drive quill adapter (2, Figure 15).
64.
Remove the retaining ring (11, Figure 14), mast guide ring (10), and lower mast bearing (9).
65.
Remove the bolt (17) and the washer (16).
66.
Push the plug (7) upward out of the support case (18).
67.
Remove the accessory and tail rotor drive and sump assembly (7, Figure 15) as follows:
67.1.
If the transmission is supported on the transportation stand illustrated in Figure 2, hoist the transmission clear of the
stand and proceed to Step 67.3..
67.2.
If the transmission is supported on the transmission stand illustrated in Figure 1, rotate the transmission 90° to the
horizontal position.
67.3.
Remove the nut (8, Figure 15), thin steel washer (9), and bracket (10).
67.4.
Remove the twelve nuts (6) and the washers (4 and 5).
67.5.
Remove the accessory and tail rotor drive and sump assembly (7) from the support case (1). Use a plastic or a
rawhide mallet to tap the sump assembly and separate it from the support case.
67.6.
Remove the gasket (3). Discard the gasket.
67.7.
Remove the four cotter pins (11), nuts (12), and steel washers (13). Discard the cotter pins. Remove the lift link
fitting (14).
67.8.
If the transmission is to be supported on the transportation stand illustrated in Figure 2, install the transmission
in the stand.
67.9.
If the transmission is supported on the transmission stand illustrated in Figure 1, rotate the transmission 90° to
the vertical position.
412-A-63-10-00-06A-530A-B
Applicable to: ALL
Page 00127-6 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00090-A-001-01
Figure 1. Transmission Assembly Stand - Application (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-06A-530A-B
ECCN EAR99
28 OCT 2024 Page 00127-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00091-A-001-01
Figure 2. Transmission Maintenance Transportation Stand - Application (Sheet 1 of 1)
412-A-63-10-00-06A-530A-B
Applicable to: ALL
Page 00127-8 28 OCT 2024
ECCN EAR99
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ICN-412-A-631000-B-97499-00092-A-001-01
Figure 3. Transmission Electrical Cable - Installation (Sheet 1 of 2)
Applicable to: ALL
412-A-63-10-00-06A-530A-B
ECCN EAR99
28 OCT 2024 Page 00127-9
BHT-412-CRO
ICN-412-A-631000-B-97499-00093-A-001-01
Figure 3. Transmission Electrical Cable - Installation (Sheet 2 of 2)
412-A-63-10-00-06A-530A-B
Applicable to: ALL
Page 00127-10 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00094-A-001-01
Figure 4. Neck, Scupper, and External Oil Hoses - Installation (Sheet 1 of 2)
Applicable to: ALL
412-A-63-10-00-06A-530A-B
ECCN EAR99
28 OCT 2024 Page 00127-11
BHT-412-CRO
ICN-412-A-631000-B-97499-00095-A-001-01
Figure 4. Neck, Scupper, and External Oil Hoses - Installation (Sheet 2 of 2)
412-A-63-10-00-06A-530A-B
Applicable to: ALL
Page 00127-12 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00096-A-001-01
Figure 5. Breather and Planetary Oil Jet Tubes - Installation (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-06A-530A-B
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28 OCT 2024 Page 00127-13
BHT-412-CRO
ICN-412-A-631000-B-97499-00097-A-001-01
Figure 6. Oil Pressure and Temperature Regulating and Indicating Components - Installation (Sheet 1 of 1)
412-A-63-10-00-06A-530A-B
Applicable to: ALL
Page 00127-14 28 OCT 2024
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ICN-412-A-631000-B-97499-00098-A-001-01
Figure 7. Oil Jets No. 1, No. 2, No. 3, No. 5, and Planetary Jet - Installation (Sheet 1 of 2)
Applicable to: ALL
412-A-63-10-00-06A-530A-B
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28 OCT 2024 Page 00127-15
BHT-412-CRO
ICN-412-A-631000-B-97499-00099-A-001-01
Figure 7. Oil Jets No. 1, No. 2, No. 3, No. 5, and Planetary Jet - Installation (Sheet 2 of 2)
412-A-63-10-00-06A-530A-B
Applicable to: ALL
Page 00127-16 28 OCT 2024
ECCN EAR99
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ICN-412-A-631000-B-97499-00100-A-001-01
Figure 8. Oil Temperature and Oil Pressure Manifolds - Installation (Sheet 1 of 2)
Applicable to: ALL
412-A-63-10-00-06A-530A-B
ECCN EAR99
28 OCT 2024 Page 00127-17
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ICN-412-A-631000-B-97499-00101-A-001-01
Figure 8. Oil Temperature and Oil Pressure Manifolds - Installation (Sheet 2 of 2)
412-A-63-10-00-06A-530A-B
Applicable to: ALL
Page 00127-18 28 OCT 2024
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ICN-412-A-631000-B-97499-00102-A-001-01
Figure 9. Top Case - Installation (Sheet 1 of 2)
Applicable to: ALL
412-A-63-10-00-06A-530A-B
ECCN EAR99
28 OCT 2024 Page 00127-19
BHT-412-CRO
ICN-412-A-631000-B-97499-01030-A-001-01
Figure 9. Top Case - Installation (Sheet 2 of 2)
412-A-63-10-00-06A-530A-B
Applicable to: ALL
Page 00127-20 28 OCT 2024
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ICN-412-A-631000-B-97499-00103-A-001-01
Figure 10. SYS 2 Hydraulic Pump and Rotor Brake Drive Quill - Installation (Sheet 1 of 1)
Applicable to: ALL
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ICN-412-A-631000-B-97499-00104-A-001-01
Figure 11. Main Input Quill - Installation (Typical) (Sheet 1 of 2)
412-A-63-10-00-06A-530A-B
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Page 00127-22 28 OCT 2024
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BHT-412-CRO
ICN-412-A-631000-B-97499-00105-A-001-01
Figure 11. Main Input Quill - Installation (Typical) (Sheet 2 of 2)
Applicable to: ALL
412-A-63-10-00-06A-530A-B
ECCN EAR99
28 OCT 2024 Page 00127-23
BHT-412-CRO
ICN-412-A-631000-B-97499-00035-A-001-01
Figure 12. Upper and Lower Planetary - Installation (Sheet 1 of 2)
412-A-63-10-00-06A-530A-B
Applicable to: ALL
Page 00127-24 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00036-A-001-01
Figure 12. Upper and Lower Planetary - Installation (Sheet 2 of 2)
Applicable to: ALL
412-A-63-10-00-06A-530A-B
ECCN EAR99
28 OCT 2024 Page 00127-25
BHT-412-CRO
ICN-412-A-631000-B-97499-00037-A-001-01
Figure 13. Ring Gear and Jet Housing - Installation (Sheet 1 of 2)
412-A-63-10-00-06A-530A-B
Applicable to: ALL
Page 00127-26 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00038-A-001-01
Figure 13. Ring Gear and Jet Housing - Installation (Sheet 2 of 2)
Applicable to: ALL
412-A-63-10-00-06A-530A-B
ECCN EAR99
28 OCT 2024 Page 00127-27
BHT-412-CRO
ICN-412-A-631000-B-97499-00106-A-002-01
Figure 14. Main Input Gear Quill and Main Case - Installation (Sheet 1 of 1)
412-A-63-10-00-06A-530A-B
Applicable to: ALL
Page 00127-28 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00039-A-001-01
Figure 15. Accessory and Tail Rotor Drive and Sump - Installation (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-06A-530A-B
ECCN EAR99
28 OCT 2024 Page 00127-29
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-06A-530A-B
Applicable to: ALL
Page 00127-30 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Transmission - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Corrosion preventive compound
Drycleaning solvent
Solvent
Paint remover
Clean cloth
C-105
C-304
C-334
C-436
C-516
AR
AR
AR
AR
AR
Remarks
Procedure
1.
Prior to cleaning, inspect the cases and sleeves for corrosion damage to threaded holes and for corrosion damage to
studs. If corrosion damage is present, refer to the inspection paragraph for the affected component to determine
whether the damage is within permitted limits.
2.
Clean the parts of the disassembled transmission with drycleaning solvent (C-304) Use a non-metallic, soft bristle
brush to dislodge deposits.
3.
Dry the parts with a clean cloth (C-516) or filtered compressed air. Do not allow bearings to spin when drying
with compressed air.
DO NOT HANDLE UNOILED BEARINGS WITH BARE HANDS.
NOTE
The parts treated per the following step may be left covered in indoor storage for approximately 150 hours
without being affected by corrosion.
4.
Coat the bearings with corrosion preventive compound (C-105) immediately after cleaning. Refer to Step 10. for the
procedure.
5.
Remove the sealant from the cases and the sleeves with a plastic scraper.
6.
Clean all the parts except the bearings by vapor degreasing with solvent (C-334).
7.
Remove the paint from all the painted parts except the manifolds (1 and 8, Figure 1) and oil jet housing (32, Figure 2)
with paint remover (C-436).
8.
Rinse the parts with water and dry with filtered compressed air.
9.
Apply a coat of lubricating oil of the type used in the transmission to all the transmission parts except the bearings.
Refer to the following step for bearing treatment.
NOTE
Parts treated per the following step may be left covered in indoor storage for approximately 150 hours
without being affected by corrosion.
10.
Immediately after cleaning bearings with drycleaning solvent (C-304), gently agitate the bearings in corrosion
preventive compound (C-105) and allow to drain dry. Apply a coat of lubricating oil of the type used in the
transmission to the bearings.
Applicable to: ALL
412-A-63-10-00-06A-258A-B
ECCN EAR99
31 MAY 2023 Page 00128-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00097-A-001-01
Figure 1. Oil Pressure and Temperature Regulating and Indicating Components - Installation (Sheet 1 of 1)
412-A-63-10-00-06A-258A-B
Applicable to: ALL
Page 00128-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00037-A-001-01
Figure 2. Ring Gear and Jet Housing - Installation (Sheet 1 of 2)
Applicable to: ALL
412-A-63-10-00-06A-258A-B
ECCN EAR99
31 MAY 2023 Page 00128-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00038-A-001-01
Figure 2. Ring Gear and Jet Housing - Installation (Sheet 2 of 2)
412-A-63-10-00-06A-258A-B
Applicable to: ALL
Page 00128-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Transmission - Inspection
Procedure
1.
Inspect the transmission and the transmission records to determine whether the transmission has been subjected to
an accident or incident outside the realm of normal usage, which would require a conditional inspection. Refer to the
BHT-412-MM, for the definition of accidents or incidents, which require that a conditional inspection be conducted.
2.
If a conditional inspection is required, conduct the inspection in accordance with 412-A-63-10-00-06A-284A-B / 00130.
If a conditional inspection is not required, proceed with the normal inspection (412-A-63-10-00-06A-280B-B / 00131).
Applicable to: ALL
412-A-63-10-00-06A-280A-B
ECCN EAR99
31 MAY 2023 Page 00129-1
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-06A-280A-B
Applicable to: ALL
Page 00129-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Transmission - Conditional Inspection
Procedure
NOTE
If a conditional inspection is required due to engine clutch misengagement, refer to the BHT-412-MM,
for instructions to conduct the inspection. If a conditional inspection is required for a reason other than
engine clutch misengagement, comply with the instructions in this paragraph.
1.
Inspect the external surfaces of the transmission for cracks, distortion, dents, and other damage. Pay particular
attention to the main support case for cracks and/or distortion. A cracked, broken, or yielded arm on the main support
case may result from a hard landing and does not necessarily indicate excessive torsional loads. If there is no
evidence that the main rotor drivetrain has been overloaded torsionally, a cracked, broken or yielded arm on the main
support case is not cause to declare the entire transmission unserviceable and nonrepairable. Refer to Step 3. for
instructions to determine whether the transmission has been overloaded torsionally.
2.
Rotate the main input quill manually and check for binding of the internal transmission parts. If any binding is evident,
determine the cause when the transmission is disassembled.
3.
Disassemble the transmission (412-A-63-10-00-06A-530A-B / 00127).
4.
Determine whether the main rotor drivetrain has been overloaded torsionally by accomplishing the following
inspections:
4.1.
Inspect the dowel pins in the main support case at the mating surface of the main case for shearing. If more than one
dowel pin is sheared, torsional overload is indicated and the entire transmission is non-airworthy and nonrepairable.
5.
Inspect all gears and pinions visually and by magnetic particle method (BHT-ALL-SPM, Standard Practices Manual).
If any cracked or broken gears in the main rotor drivetrain are found, torsional overload is indicated and the entire
transmission is non-airworthy and nonrepairable. If any cracked or broken gears in the tail rotor drivetrain are
found, accomplish the following:
5.1.
Inspect the support case for yielding in accordance with Figure 1.
5.2.
Inspect the accessory and tail rotor drive and sump case for damage to the bore of the tail rotor drive quill and the bore
of the accessory and tail rotor drive quill. Refer to 412-A-63-10-00-21A-530A-B / 00203 for the bore diameter limits.
5.3.
Replace the following parts:
NOMENCLATURE
PART NUMBER
Accessory and Drive Quill Pinion
212-040-150
Tail Rotor Quill Gear
212-040-151
Offset Accessory and Tail Rotor Drive Quill Gear
212-040-201
Offset Accessory and Tail Rotor Drive Quill Pinion
212-040-202
Applicable to: ALL
412-A-63-10-00-06A-284A-B
ECCN EAR99
31 MAY 2023 Page 00130-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00133-A-001-01
Figure 1. Main Support Case (212-040-054-109) and Lift Link Fitting - Damage Limits (Sheet 1 of 5)
412-A-63-10-00-06A-284A-B
Applicable to: ALL
Page 00130-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00134-A-001-01
Figure 1. Main Support Case (212-040-054-109) and Lift Link Fitting - Damage Limits (Sheet 2 of 5)
Applicable to: ALL
412-A-63-10-00-06A-284A-B
ECCN EAR99
31 MAY 2023 Page 00130-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00135-A-001-01
Figure 1. Main Support Case (212-040-054-109) and Lift Link Fitting - Damage Limits (Sheet 3 of 5)
412-A-63-10-00-06A-284A-B
Applicable to: ALL
Page 00130-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00136-A-001-01
Figure 1. Main Support Case (212-040-054-109) and Lift Link Fitting - Damage Limits (Sheet 4 of 5)
Applicable to: ALL
412-A-63-10-00-06A-284A-B
ECCN EAR99
31 MAY 2023 Page 00130-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00137-A-001-01
Figure 1. Main Support Case (212-040-054-109) and Lift Link Fitting - Damage Limits (Sheet 5 of 5)
412-A-63-10-00-06A-284A-B
Applicable to: ALL
Page 00130-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Transmission - Normal Inspection
Procedure
NOTE
Limits charts are provided to show the required fit between mating parts. It is not intended that all
dimensions listed on the limits charts be checked as a prescribed overhaul procedure; however, parts
that show evidence of wear or physical damage must be checked dimensionally.
1.
Visually inspect the parts shown in Figure 1. If any parts show evidence of wear or physical damage when inspected
during the subsequent steps, measure the dimensions to determine whether the part is permitted. Damage limits are
shown in Figure 1.
2.
Inspect the mast driving adapter (3, Figure 2) for corrosion damage and wear and damaged spline teeth.
3.
Inspect the planetary support upper and lower bearings (5 and 12) for roughness, spalling, scoring, pitting, brinelling,
corrosion damage, cracked or broken retainers, and for wear. Damage that can be detected visually or by feel is
not permitted.
4.
Inspect the lower mast bearing (9, Figure 3) and the input quill support bearing (2, Figure 4) as follows:
4.1.
Inspect for spalling, scoring, pitting, brinelling, flaking, corrosion damage on rolling elements or races, and cracked
or broken retainers. Those damages are not permitted. Superficial corrosion is permitted. Corrosion damage
in excess of superficial is not permitted.
4.2.
Inspect the bearing rollers for nicks, cuts and scratches. Nicks, cuts and scratches on the bearing rollers are permitted
provided they are too small to be felt with a 0.020-inch (0.51-mm) spherical radius inspection probe and provided the
total affected area does not exceed 10% of the contact area at any point.
4.3.
Inspect the bearing rollers and races for circumferential scratches. Minor circumferential scratches are permitted on
the rollers and races provided they cannot be felt with a 0.020-inch (0.51-mm) spherical radius inspection probe and
provided the affected area does not exceed 10% of the contact area at any point.
4.4.
Inspect the bearing rollers for wear pattern. Refer to Figure 5 for examples of acceptable and unacceptable wear
patterns.
5.
Inspect the liners (6, 11, and 13, Figure 2) for wear and distortion. Wear and/or damage in excess of superficial is
not permitted.
6.
Inspect the manifolds (1 and 8, Figure 6), and oil jet housings (32, 34, and 39, Figure 7) for corrosion, mechanical
damage, and damaged threads.
7.
Inspect all oil jets for bends, mechanical damage, and corrosion. Pay particular attention to the area of the slots.
Inspect the jets for cracks by magnetic particle method (BHT-ALL-SPM, Standard Practices Manual). No cracks are
permitted. When inspecting the jets by magnetic particle method, a single indication of a straight line crack across the
inner end of the oil jet may be a false indication termed a smudge line, which is typical of the method of manufacture.
8.
Inspect the hose assemblies (11 and 27, Figure 8) and related fittings for damaged threads, distortion, and
deterioration.
9.
Inspect the tubes (7 and 17) and related fittings for damaged threads, distortion, and cracks.
10.
Inspect the neck and scupper assembly (1) and the neck and scupper support bracket (2) for cracks and distortion.
11.
Inspect the following tubes and related fittings for damaged threads, distortion, and cracks:
NOMENCLATURE
FIGURE
Tube
(4, Figure 9)
Tube
(7, Figure 9)
Tube
(18, Figure 9)
Oil transfer tube
(3, Figure 10)
Oil transfer tube
(13, Figure 11)
Oil transfer tube
(19, Figure 4)
Applicable to: ALL
412-A-63-10-00-06A-280B-B
ECCN EAR99
31 MAY 2023 Page 00131-1
BHT-412-CRO
12.
Inspect the pressure regulating valve assembly (10, Figure 6), thermostatic switch (12), oil pressure switch (7), oil
pressure transmitter (5), and thermobulb (9, Figure 10) for damaged threads and mechanical damage.
13.
Visually inspect all the parts for damage and excessive wear. Inspect the gears and the splines for chipped, broken,
or worn teeth. Check the bearings for smooth operation and for indications of failure or excessive wear. If metal
particles were found in the transmission at disassembly or if there is evidence of metal particles going through the
gear meshes, carefully examine the gear teeth and the bearings for dents and cuts. Inspect the cases and the sleeves
for corrosion damage, excessive wear, and loose or damaged bearing liners.
14.
Inspect the upper sun gear (7, Figure 2) and the lower sun gear (14) for chipped, dented, pitted, spalled, or scuffed
gear teeth. Refer to Figure 12 for examples of acceptable and unacceptable gear wear patterns.
15.
Inspect the following parts by magnetic particle inspection. Demagnetize the parts after the magnetic particle
inspection. Refer to Table 2 and the BHT-ALL-SPM, Standard Practices Manual for the procedure.
FIGURE AND INDEX NUMBER
NOMENCLATURE
3, Figure 2
Mast driving adapter
4, Figure 2
Extension
6, Figure 2
Liner (outer)
7, Figure 2
Upper sun gear
11, Figure 2
Liner (outer)
13, Figure 2
Liner (inner)
14, Figure 2
Lower sun gear
5, Figure 7
Ring gear
2, Figure 13
Tail rotor drive quill adapter
Table 2. Magnetic Particle Inspection
PART NUMBER
NOMENCLATURE
ITEM AND FIGURE
SET UP AND MAGNETIZATION CURRENT REQUIREMENTS
TRANSMISSION ASSEMBLY (412-040-002-105, -107, AND -111)
412-040-107-101
Mast Driving Adapter
3, Figure 2
SET UP:
Place part over a 2-inch diameter central conductor.
Current for primary diameters, magnetize at 2360 amps.
Large I.D. of part: Magnetize at three approximately equally spaced radial locations on central conductor.
SET UP: 5 TURN COIL SHOT:
Disc-shaped portion of part: Place part in bottom of coil.
Magnetize at 3000 amps.
Rotate part 1/4 turn and repeat.
412-040-109-101
Extension
4, Figure 2
SET UP:
Place part over a 2-inch diameter central conductor.
Current for primary diameters, magnetize at 2110 amps.
Omit coil shot.
204-040-337-001
Outer Liner
6, Figure 2
412-A-63-10-00-06A-280B-B
Applicable to: ALL
Page 00131-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Table 2. Magnetic Particle Inspection (continued)
SET UP:
Place part over a 2-inch diameter central conductor.
Current for primary diameters, magnetize at 1560 amps.
Large I.D. of part: Magnetize at three approximately equally spaced radial locations on central conductor.
Omit coil shot.
204-040-338-001
Outer Liner
11, Figure 2
SET UP:
Place part over a 2-inch diameter central conductor.
Current for primary diameters, magnetize at 2370 amps.
Optional current for secondary diameters, magnetize at 1380 amps.
Large I.D. of part: Magnetize at three approximately equally spaced radial locations on central conductor.
SET UP: 5 TURN COIL SHOT:
Disc-shaped part: Lay part flat in bottom of coil.
Magnetize at 3000 amps.
Rotate part 1/4 turn and repeat.
205-040-230-003
Upper Sun Gear
7, Figure 2
SET UP:
Place part over a 2-inch diameter central conductor.
Current for primary diameters, magnetize at 1930 amps.
Large I.D. of part: Magnetize at three approximately equally spaced radial locations on central conductor.
SET UP: 5 TURN COIL SHOT:
Disc-shaped part: Place part in bottom of coil.
Magnetize at 3000 amps.
Rotate part 1/4 turn and repeat.
205-040-229-003
Lower Sun Gear
14, Figure 2
SET UP:
Place part over a 2-inch diameter central conductor.
Current for primary diameters, magnetize at 2990 amps.
SET UP: 5 TURN COIL SHOT:
Disc-shaped part: Place part in bottom of coil.
Magnetize at 3000 amps.
Rotate part 1/4 turn and repeat.
205-040-231-009
Ring Gear
15, Figure 7
SET UP:
Applicable to: ALL
412-A-63-10-00-06A-280B-B
ECCN EAR99
31 MAY 2023 Page 00131-3
BHT-412-CRO
Table 2. Magnetic Particle Inspection (continued)
Place part over a 2-inch diameter central conductor.
Current for primary diameters, magnetize at 3580 amps.
Optional current for secondary diameters, magnetize at 2000 amps.
Large I.D. of part: Magnetize at seven approximately equally spaced radial locations on central conductor.
Omit coil shot.
212-040-206-101
Tail Rotor Drive Quill Adapter
2, Figure 13
Refer to 212 HP magnetic particle inspection.
NOTES:
1. Magnetization currents provided are applicable to magnetic particle inspection apparatus using Direct Current (DC) . If an
Alternating Current (AC) apparatus is used, adjust the current as follows: AC= 0.667 x DC.
2. Ferrous parts requiring magnetic particle inspection that are not addressed in the attached material, are to be inspected in
accordance with the general procedures outlined in ASTM E1444 standard practices (BHT-ALL-SPM, Chapter 6, Standard
Practices Manual).
3. Part numbers listed apply to all successive dash numbers for that component unless otherwise specified.
NOTE
Limits charts are provided to show the required fit between the mating parts. It is not intended that all
dimensions listed on the limits charts be checked as a prescribed overhaul procedure; however, parts
that show evidence of wear or physical damage must be checked dimensionally.
16.
Inspect the parts dimensionally as required (Figure 1).
17.
Refer to 412-A-63-10-00-08A-280A-B / 00139, 412-A-63-10-00-09A-280A-B / 00144, and 412-A-63-10-00-10A-280A-B
/ 00149 for the inspection of the top, main, and support cases.
18.
Refer to 412-A-63-10-00-11A-280A-B / 00155 for the inspection of the planetary ring gear, upper planetary, and
lower planetary assemblies.
19.
Refer to 412-A-63-10-00-21A-284A-B / 00205 for the inspection of the accessory and tail rotor drive and sump
assembly.
20.
Refer to 412-A-63-10-00-14A-280A-B / 00170 and 412-A-63-10-00-15A-280A-B / 00175 for the inspection of the
main input gear quill.
21.
Refer to 412-A-63-10-00-16A-280A-B / 00180, 412-A-63-10-00-17A-280A-B / 00185, and 412-A-63-10-00-18A-280A-B
/ 00190 for the inspection of the main input quill.
22.
Refer to 412-A-63-10-00-19A-280A-B / 00195 for the inspection of the generator (or system 2 hydraulic pump)
drive quill.
23.
Refer to 412-A-63-10-00-20A-280A-B / 00200 for the inspection of the offset accessory drive quill.
24.
Refer to 412-A-63-10-00-29A-280A-B / 00246 for the inspection of the rotor brake drive quill.
412-A-63-10-00-06A-280B-B
Applicable to: ALL
Page 00131-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00112-A-001-01
Figure 1. Transmission Gears, Bearings, and Liners - Damage Limits (Sheet 1 of 2)
Applicable to: ALL
412-A-63-10-00-06A-280B-B
ECCN EAR99
31 MAY 2023 Page 00131-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00113-A-001-01
Figure 1. Transmission Gears, Bearings, and Liners - Damage Limits (Sheet 2 of 2)
412-A-63-10-00-06A-280B-B
Applicable to: ALL
Page 00131-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00035-A-001-01
Figure 2. Upper and Lower Planetary - Installation (Sheet 1 of 2)
Applicable to: ALL
412-A-63-10-00-06A-280B-B
ECCN EAR99
31 MAY 2023 Page 00131-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00036-A-001-01
Figure 2. Upper and Lower Planetary - Installation (Sheet 2 of 2)
412-A-63-10-00-06A-280B-B
Applicable to: ALL
Page 00131-8 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00106-A-001-01
Figure 3. Main Input Gear Quill and Main Case - Installation (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-06A-280B-B
ECCN EAR99
31 MAY 2023 Page 00131-9
BHT-412-CRO
ICN-412-A-631000-B-97499-00104-A-001-01
Figure 4. Main Input Quill - Installation (Typical) (Sheet 1 of 2)
412-A-63-10-00-06A-280B-B
Applicable to: ALL
Page 00131-10 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00105-A-001-01
Figure 4. Main Input Quill - Installation (Typical) (Sheet 2 of 2)
Applicable to: ALL
412-A-63-10-00-06A-280B-B
ECCN EAR99
31 MAY 2023 Page 00131-11
BHT-412-CRO
ICN-412-A-631000-B-97499-00114-A-001-01
Figure 5. Roller Bearing - Wear Patterns (Sheet 1 of 1)
412-A-63-10-00-06A-280B-B
Applicable to: ALL
Page 00131-12 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00097-A-001-01
Figure 6. Oil Pressure and Temperature Regulating and Indicating Components - Installation (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-06A-280B-B
ECCN EAR99
31 MAY 2023 Page 00131-13
BHT-412-CRO
ICN-412-A-631000-B-97499-00037-A-001-01
Figure 7. Ring Gear and Jet Housing - Installation (Sheet 1 of 2)
412-A-63-10-00-06A-280B-B
Applicable to: ALL
Page 00131-14 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00038-A-001-01
Figure 7. Ring Gear and Jet Housing - Installation (Sheet 2 of 2)
Applicable to: ALL
412-A-63-10-00-06A-280B-B
ECCN EAR99
31 MAY 2023 Page 00131-15
BHT-412-CRO
ICN-412-A-631000-B-97499-00094-A-001-01
Figure 8. Neck, Scupper, and External Oil Hoses - Installation (Sheet 1 of 2)
412-A-63-10-00-06A-280B-B
Applicable to: ALL
Page 00131-16 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00095-A-001-01
Figure 8. Neck, Scupper, and External Oil Hoses - Installation (Sheet 2 of 2)
Applicable to: ALL
412-A-63-10-00-06A-280B-B
ECCN EAR99
31 MAY 2023 Page 00131-17
BHT-412-CRO
ICN-412-A-631000-B-97499-00096-A-001-01
Figure 9. Breather and Planetary Oil Jet Tubes - Installation (Sheet 1 of 1)
412-A-63-10-00-06A-280B-B
Applicable to: ALL
Page 00131-18 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00100-A-001-01
Figure 10. Oil Temperature and Oil Pressure Manifolds - Installation (Sheet 1 of 2)
Applicable to: ALL
412-A-63-10-00-06A-280B-B
ECCN EAR99
31 MAY 2023 Page 00131-19
BHT-412-CRO
ICN-412-A-631000-B-97499-00101-A-001-01
Figure 10. Oil Temperature and Oil Pressure Manifolds - Installation (Sheet 2 of 2)
412-A-63-10-00-06A-280B-B
Applicable to: ALL
Page 00131-20 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00102-A-001-01
Figure 11. Top Case - Installation (Sheet 1 of 2)
Applicable to: ALL
412-A-63-10-00-06A-280B-B
ECCN EAR99
31 MAY 2023 Page 00131-21
BHT-412-CRO
ICN-412-A-631000-B-97499-01030-A-001-01
Figure 11. Top Case - Installation (Sheet 2 of 2)
412-A-63-10-00-06A-280B-B
Applicable to: ALL
Page 00131-22 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00115-A-001-01
Figure 12. Transmission Sun Gear - Wear Patterns (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-06A-280B-B
ECCN EAR99
31 MAY 2023 Page 00131-23
BHT-412-CRO
ICN-412-A-631000-B-97499-00039-A-001-01
Figure 13. Accessory and Tail Rotor Drive and Sump - Installation (Sheet 1 of 1)
412-A-63-10-00-06A-280B-B
Applicable to: ALL
Page 00131-24 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Transmission - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Chromic acid treatment
Epoxy polyamide primer
India stone
C-103
C-204
C-464
AR
AR
AR
Remarks
Procedure
DUPLEX BEARINGS ARE MARKED WITH SERIAL NUMBERS AND MUST BE REPLACED IN
MATCHED PAIRS.
NOTE
All the parts reworked or repaired shall be inspected prior to use or assembly.
1.
Replace all seals, gaskets, preformed packings, cork plugs and cotter pins on reassembly.
2.
Replace parts that are cracked, broken, warped, distorted, or have malformed threads.
3.
Replace all the parts that exceed allowable tolerances given in applicable limits charts.
4.
Replace corroded, nicked, pitted, scratched, or dented parts that cannot be repaired in accordance with the repair
procedures set forth in this manual.
ROLLER BEARING INNER AND OUTER RACE MUST BE A MATCHED SET WITH THE SAME SERIAL
NUMBER ON BOTH RACES.
5.
Assemble the roller bearing inner and outer races with matched or the same serial numbers.
6.
The serial number on the ground shim plate must conform to the serial number on the sleeve or the case.
BEARING SPACERS MUST BE A MATCHED SET WITH THE SAME SERIAL NUMBER ON BOTH
SPACERS.
7.
The bearing spacers are finished ground together as a matched set and serialized for replacement.
8.
Repair the oil temperature manifold (14, Figure 1) as follows:
NOTE
Repair of the manifold is limited to the removal of the damaged helicoil and the installation of a modified
Rosan insert.
8.1.
Remove the damaged helicoil used for the oil jet No. 7 (13) retention screw.
8.2.
Drill out the hole where the helicoil was removed with a letter size F twist drill to 0.335 inch (8.51 mm) maximum depth.
8.3.
Tap the 5/16-18 UNC-3B threads to 0.280 inch (7.11 mm) full thread depth.
8.4.
Treat the tapped hole with chromic acid treatment (C-103) treatment (BHT-ALL-SPM, Standard Practices Manual).
NOTE
The top four threads of the Rosan insert are expanded to provide interference fit.
Applicable to: ALL
412-A-63-10-00-06A-685A-B
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31 MAY 2023 Page 00132-1
BHT-412-CRO
8.5.
Make an insert from a Rosan insert (H2R-205SC-7). Machine the overall length to 0.250 inch (6.35 mm) by removing
materials from end where the external threads are cut back. Treat the insert with chromic acid treatment (C-103)
(BHT-ALL-SPM, Standard Practices Manual).
8.6.
Apply epoxy polyamide primer (C-204) to the external threads of the insert modified in Step 8.5.. Install the insert in
the manifold while the primer is wet with a hex wrench. Install the insert 0.030 inch (0.76 mm) below the surface of
the manifold.
9.
Replace all bearings that show evidence of spalling, scoring, pitting, brinelling, flaking, or corrosion damage on the
roller elements or races, or that have cracked or broken retainers, or that do not roll smoothly.
10.
Replace roller bearings that show evidence of spalling, scoring, pitting, brinelling, or large corrosion pitting damage on
the rolling elements or races, or that have cracked or broken retainers. Minor nicks, cuts, or scratches are permitted
on rollers provided they are too small to be felt with a probe having an end radius of 0.030 inch (0.76 mm), and
provided the total affected area does not exceed 10% of the contact area at any point. Minor circumferential scoring is
permitted on rollers and races provided it cannot be felt with a probe having end radius of 0.030 inch (0.76 mm) and
provided the affected area does not exceed 10% of the contact area at any point (Figure 2).
11.
Replace bevel gears that are spalled or scuffed or that have improper wear patterns. Replace spur gears that are
spalled or that are scuffed beyond the limits shown in Figure 3. If metal particles are found in the transmission during
disassembly, or if there is evidence of metal particles going through gear meshes, the gear teeth should be carefully
examined for indentions and cuts. Repair minor nicks, scratches, and burrs on the splines and gear teeth by dressing
with a fine india stone (C-464) in accordance with the inspection requirements.
12.
Touch up the transmission parts where corrosion protective chemical film has been removed. Refer to the
BHT-ALL-SPM, Standard Practices Manual for the procedure to accomplish the corrosion protective treatment
for localized areas.
13.
Refer to 412-A-63-10-00-08A-685A-B / 00140, 412-A-63-10-00-09A-685A-B / 00145, and 412-A-63-10-00-10A-685A-B
/ 00150 for the repair of the top case, main bevel gear case, and main support case.
14.
Refer to 412-A-63-10-00-11A-685A-B / 00156, 412-A-63-10-00-12A-685A-B / 00161, and 412-A-63-10-00-13A-685A-B
/ 00166 for repair of planetary ring gear, upper planetary assembly, and lower planetary assembly.
15.
Refer to 412-A-63-10-00-21A-685A-B / 00207 for the repair of the accessory and tail rotor drive and sump assembly.
16.
Refer to 412-A-63-10-00-14A-685A-B / 00171 and 412-A-63-10-00-15A-685A-B / 00176 for the repair of the main
input gear quill.
17.
Refer to 412-A-63-10-00-16A-685A-B / 00181, 412-A-63-10-00-17A-685A-B / 00186, and 412-A-63-10-00-18A-685A-B
/ 00191 for the repair of the main input quill.
18.
Refer to 412-A-63-10-00-19A-685A-B / 00196 for the repair of the generator (or system 2 hydraulic pump) drive quill.
19.
Refer to 412-A-63-10-00-20A-685A-B / 00201 for the repair of the offset accessory drive quill.
20.
Refer to 412-A-63-10-00-22A-685A-B / 00212 for the repair of the rotary oil pump.
21.
Refer to 412-A-63-10-00-25A-685A-B / 00227 for the repair of the accessory tail rotor drive quill.
22.
Refer to 412-A-63-10-00-26A-685A-B / 00232 and 412-A-63-10-00-27A-685A-B / 00237 for the repair of the
tail rotor drive quill.
23.
Refer to 412-A-63-10-00-28A-685A-B / 00242 for the repair of the hydraulic drive quill.
24.
Refer to 412-A-63-10-00-29A-685A-B / 00247 for the repair of the rotor brake drive quill.
412-A-63-10-00-06A-685A-B
Applicable to: ALL
Page 00132-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00100-A-001-01
Figure 1. Oil Temperature and Oil Pressure Manifolds - Installation (Sheet 1 of 2)
Applicable to: ALL
412-A-63-10-00-06A-685A-B
ECCN EAR99
31 MAY 2023 Page 00132-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00101-A-001-01
Figure 1. Oil Temperature and Oil Pressure Manifolds - Installation (Sheet 2 of 2)
412-A-63-10-00-06A-685A-B
Applicable to: ALL
Page 00132-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00114-A-001-01
Figure 2. Roller Bearing - Wear Patterns (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-06A-685A-B
ECCN EAR99
31 MAY 2023 Page 00132-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00115-A-001-01
Figure 3. Transmission Sun Gear - Wear Patterns (Sheet 1 of 1)
412-A-63-10-00-06A-685A-B
Applicable to: ALL
Page 00132-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Transmission - Assembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Backlash Tool
Backlash Tool
Backlash Tool
Pusher Set
Jacking Screw Set
Cover and Lift Plate Assembly
212-040-001-3GIF-1
212-040-001-19GIF-1
205-040-300-1GIF-1
T101586
T102064
T103211-101
1
1
1
1
1
1
Remarks
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Corrosion preventive compound
Corrosion preventive compound
Zinc chromate primer
Drycleaning solvent
Sealant
MEK
Sealant
Lockwire
C-105
C-128
C-201
C-304
C-308
C-309
C-328
C-405
AR
AR
AR
AR
AR
AR
AR
AR
Remarks
Procedure
DO NOT HANDLE UNOILED BEARINGS WITH BARE HANDS.
NOTE
Use new preformed packings, gaskets, seals, and cotter pins when assembling transmission.
NOTE
Immediately prior to installing the parts, coat the packings and mating surfaces with the same oil used in
the transmission.
1.
If not previously accomplished, assemble the stand (Figure 1 or Figure 2) that will be used to support the transmission
during the assembly procedures. The stand illustrated in Figure 1 is the preferred stand to use for the transmission
assembly.
2.
Make sure that the shims of the proper dimensions have been installed. Refer to 412-A-63-10-00-09A-710A-B /
00146, 412-A-63-10-00-14A-710A-B / 00172, 412-A-63-10-00-15A-710A-B / 00177, 412-A-63-10-00-16A-710A-B /
00182, 412-A-63-10-00-17A-710A-B / 00187, 412-A-63-10-00-18A-710A-B / 00192, 412-A-63-10-00-19A-710A-B /
00197, and 412-A-63-10-00-21A-710A-B / 00208 for information on the required shim thickness.
3.
Clean all the parts with drycleaning solvent (C-304) and drain. Make sure that all the parts that were coated with
corrosion preventive compound (C-105) (fingerprint remover) are thoroughly cleaned. Coat the parts with the same
oil used in the transmission after cleaning.
4.
Install the support case (18, Figure 3) in the stand (Figure 1 or Figure 2).
5.
Remove any particles of magnesium from the case that might become detached, and clean the case thoroughly.
6.
If the adjustable stand illustrated in Figure 1 is being used, invert the case in the stand.
7.
Lubricate a new packing (8, Figure 3) with the same oil used in the transmission.
Applicable to: ALL
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BHT-412-CRO
8.
Put the new packing (8) on the plug (7) and install the plug in the support case (18) with the hole aligned for the
bolt (17).
9.
Install the bolt (17) and the washer (16). Make sure that the bolt head contacts the support case (18) before the
threaded end bottoms on the plug (7). Tighten the bolt.
10.
Secure the plug (7) to the support case (18) with lockwire (C-405).
11.
Return the support case (18) to the upright position.
12.
Install the lower mast bearing (9) in the liner of the support case (18).
13.
Install the mast guide ring (10) on the lower mast bearing (9) and secure with the retaining ring (11).
14.
Heat the support case (18) at the port for offset accessory drive quill (15) with a heat lamp. Coat the mating surfaces
of the accessory drive sleeve and the case with the same oil used in the transmission.
DO NOT TAP ON THE GEAR OR DAMAGE TO THE GEAR WILL OCCUR.
15.
Install the offset accessory drive quill (15). If necessary tap on the quill to seat it in the case but do not tap on the gear.
16.
Install the six steel washers (14) and the nuts (13). Torque the nuts 50 to 70 inch-pounds (5.65 to 7.91 Nm) and
secure with the new cotter pins (12).
17.
Lubricate a new packing (25) with the same oil used in the transmission.
18.
Install the new packing (25) on the main case (3).
19.
Heat the support case (18) with a heat lamp.
20.
Install the main case (3) on the support case (18) then tap the main case down into position and make sure that
the packing (25) is properly seated and not damaged.
21.
Install the washers (23), bracket (24), and nut (22) on the stud, as shown in Figure 3. Torque the nut 230 to 250
inch-pounds (25.99 to 28.25 Nm).
22.
Install the washers (6), thin steel washers (5), and nuts (4) on all the upper studs. Torque the nuts 230 to 250
inch-pounds (25.99 to 28.25 Nm).
23.
Install the washers (26), thin steel washers (27), and nuts (28) on the lower studs. Torque the nuts 230 to 250
inch-pounds (25.99 to 28.25 Nm).
24.
Heat the upper portion of the main case (3) with a heat lamp.
25.
Lubricate a new packing (2) and the mating surface of the main input gear quill (1) with the same oil used in the
transmission.
26.
Install the new packing (2) on the main input gear quill (1).
27.
Align the FWD arrow on the main input gear quill (1) with the forward side of the main case (3). Carefully install the
gear quill in the main case. Make sure that the gearshaft engages the roller bearing and the spline in the offset
accessory drive quill (15). Rotate the gearshaft of the quill slightly to engage the splines.
NOTE
As a alternate, you can use the backlash tool set 412-240-006-101.
28.
For transmission 412-040-002, put the backlash tool 204-040-001-17 PAT 1, on the main input gear quill (1). Install
four bolts to secure the tool to the quill and the main case (3). Tighten the clamp on the backlash tool to prevent the
shaft from turning in quill.
29.
Install the main input quill (6, Figure 4) as follows:
29.1.
Make sure the bearing (2) is installed.
29.2.
Remove the set screws (17) from the studs on the transmission case.
412-A-63-10-00-06A-710A-B
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Page 00133-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
29.3.
Remove the three nuts (11, Figure 5) from the pusher set (T101586) stud (12). Install the three studs (12) in holes
where set screws were removed. Refer to Figure 5 for view of installed studs.
29.4.
Pass through the rotor brake quill port and install the workaid plug (2) to hold the rollers of the bearing (3) against the
outer race of the bearing. Refer to Figure 5 for a sectional view of the installed workaid.
29.5.
Heat the case in the area of the quill port with a heat lamp or a 250 watt light bulb. The heating time will vary, but heat
the case until the area near the quill port is hot to touch.
29.6.
Lubricate new packings (18 and 20, Figure 4) with the same oil used in the transmission.
29.7.
Install the new packings (18 and 20) on the oil transfer tube (19). Put the tube in the transmission case..
29.8.
Lubricate new packings (4 and 5) with the same oil used in the transmission.
MAKE SURE TO LEAVE THE CENTER GROOVE OPEN FOR OIL CIRCULATION OR DAMAGE TO
TRANSMISSION MAY OCCUR.
29.9.
Install the new packing (5) in the groove nearest the flange of the main input quill (6) and install the new packing (4) in
the groove nearest the pinion. Leave the center groove open for oil circulation.
MAKE SURE THE OIL TRANSFER TUBE IS INSTALLED OR DAMAGE TO TRANSMISSION MAY
OCCUR.
29.10.
Put the input quill pinion (6, Figure 5) on the pusher set (T101586) stud (12) with the union for the drain tube at
the bottom.
29.11.
Carefully slide the quill into the transmission case. Align the input quill pinion (6) teeth with the input gear quill (5)
teeth. Align the front of the input quill pinion with the bearing rollers (3).
WORKAID PLUG MUST BE REMOVED BEFORE FULLY SEATING THE QUILL. OTHERWISE, THE
PLUG COULD BE FORCED AGAINST THE OIL JET NO. 6 AND CAUSE DAMAGE.
29.12.
Install the three nuts (11) and tighten evenly to keep the quill aligned. When the quill is started into the bearing,
remove the workaid plug (2), through the rotor brake quill port, to prevent pushing workaid into oil jet No. 6, if installed.
29.13.
Continue tightening the nuts (11) to fully seat the quill. When the quill is fully seated, loosen the nuts and remove the
pusher set (T101586) studs (12).
29.14.
Install the set screws (17, Figure 4) on the studs at 3, 7 and 11 o'clock positions.
29.15.
Install the aluminum washer (9), clip (10), and nut (11) on lower right stud (5 o'clock position). Install the six aluminum
washers (14), six thin steel washers (13), and six nuts (12) on the remaining studs. Torque the nuts (11 and 12) 160
to 190 inch-pounds (18 to 21 Nm).
29.16.
Rotate the curvic adapter on the outboard end of the main input quill (6) by hand. Check for a small amount of
backlash. A small amount of backlash must be evident.
29.17.
Lubricate a new packing (16) with the same oil used in the transmission and install on the plug (15).
29.18.
Install the plug (15) in the main input quill (6). Tighten the plug and secure with lockwire (C-405).
29.19.
Install the three aluminum washers (7) and the screws (8). Tighten the screws and secure to the quill with lockwire
(C-405).
29.20.
Put the same oil used in the transmission on the threads of the union (22) and the new packing (23). Install the new
packing on the union and install the union on the main input quill (6).
29.21.
Install the tube (seal drain) (21) on the union (22).
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28 OCT 2024 Page 00133-3
BHT-412-CRO
29.22.
Put the opposite end of the tube (seal drain) (21) to drain into the scupper adjacent to the internal oil filter on the
transmission sump.
29.23.
Tighten the nut (24).
29.24.
Install the clamp on the tube (seal drain) (21). Secure the clamp to the bracket (10, Figure 6).
30.
Install the hydraulic pump drive quill (4, Figure 7) as follows:
THE SPIRAL BEVEL PINION IN THE HYDRAULIC PUMP DRIVE QUILL ASSEMBLY 204-040-379-003
HAS SIX HOLES IN THE WEB AND SHALL BE INSTALLED IN TRANSMISSIONS 412-040-002. THE
SPIRAL BEVEL PINION IN THE HYDRAULIC PUMP DRIVE QUILL ASSEMBLY 204-040-379-101 HAS
FOUR HOLES IN THE WEB AND SHALL BE INSTALLED IN TRANSMISSIONS 412-040-004. SEVERE
DAMAGE TO THE TRANSMISSION WILL RESULT IF THIS CAUTION IS NOT FOLLOWED.
EXERCISE CAUTION TO PREVENT DAMAGE TO HYDRAULIC PUMP DRIVE QUILL PINION AND
SPIRAL BEVEL GEAR TEETH. ROTATE QUILL PINION SLIGHTLY AS THE QUILL IS BEING
INSTALLED TO PERMIT MESHING OF GEARS.
30.1.
Heat the transmission main case in the area of the quill port with a heat lamp until the case is too hot to touch.
30.2.
Lubricate a new packing (12) with the same oil used in the transmission and install on the hydraulic pump drive quill (4).
MAKE SURE THE OIL HOLE IN THE QUILL SLEEVE IS UP OR DAMAGE TO THE QUILL MAY OCCUR.
30.3.
Carefully insert the hydraulic pump drive quill (4) into the transmission case with the oil hole in the quill sleeve up.
Exercise caution to prevent damage to the quill teeth. Rotate the quill pinion slightly to permit gear meshing. Align the
holes and install the six washers (5), steel washers (6), and bolts (7). Torque the bolts 160 to 190 inch-pounds (18
to 21 Nm).
30.4.
Install the cover (9) and the new gasket (8) with the six steel washers (10) and the nuts (11). Tighten the nuts.
31.
If previously removed, install the rotor brake drive quill (13, Figure 7) as follows:
THE SPIRAL BEVEL PINION IN THE ROTOR BRAKE QUILL ASSEMBLY 412-040-123-101 HAS SIX
HOLES IN THE WEB AND SHALL BE INSTALLED IN TRANSMISSIONS 412-040-002. THE SPIRAL
BEVEL PINION IN THE ROTOR BRAKE QUILL ASSEMBLY 412-040-123-103 HAS FOUR HOLES IN
THE WEB AND SHALL BE INSTALLED IN TRANSMISSIONS 412-040-004. SEVERE DAMAGE TO
THE TRANSMISSION WILL RESULT IF THIS CAUTION IS NOT FOLLOWED.
EXERCISE CAUTION TO PREVENT DAMAGE TO ROTOR BRAKE PINION AND SPIRAL BEVEL
GEAR TEETH. ROTATE QUILL PINION SLIGHTLY AS THE QUILL IS BEING INSTALLED TO PERMIT
MESHING OF GEARS.
31.1.
Clean oil, sealant, and other residue from the mounting surface and the rotor brake bore.
31.2.
Heat the main case in the area of the rotor brake bore with a heat lamp until the case is too hot to touch.
31.3.
Verify that the correct rotor brake drive quill is being installed in the transmission per the previous caution.
31.4.
Lubricate a new packing (17) with the same oil used in the transmission and install on the rotor brake drive quill (13).
31.5.
Apply corrosion preventive compound (C-128) to the rotor brake drive quill (13) and the transmission case as follows:
412-A-63-10-00-06A-710A-B
Applicable to: ALL
Page 00133-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
31.5.1.
Mix the corrosion preventive compound (C-128) with MEK (C-309) to obtain a brushable consistency.
31.5.2.
Apply a thin even coat of corrosion preventive compound (C-128) to the rotor brake drive quill (13) from the edge of
the packing groove, nearest the quill flange, to the outer edge of the flange.
31.5.3.
Apply a thin even coat of corrosion preventive compound (C-128) to the transmission case from the edge of the bore
that mates with the rotor brake drive quill (13) to the outer edge of the case shim.
DURING ROTOR BRAKE QUILL INSTALLATION DO NOT STRIKE END OF PINION SHAFT OR
FLANGED ADAPTER. IF NECESSARY, DRIVE QUILL INTO PLACE BY LIGHTLY TAPPING AROUND
THE QUILL SLEEVE FLANGE NEAR THE OUTER EDGES WITH A RUBBER MALLET.
MAKE SURE THE OIL HOLE IN THE QUILL SLEEVE IS UP OR DAMAGE TO THE QUILL MAY OCCUR.
31.6.
Carefully insert the rotor brake drive quill (13) into the transmission case with the oil hole in the quill sleeve up.
Exercise caution to prevent damage to the quill teeth. Rotate the quill pinion slightly to permit gear meshing. Align
the holes and install the six bolts (14) with the washers (15 and 16). Torque the bolts 160 to 190 inch-pounds (18
to 21 Nm).
31.7.
Check the backlash as follows:
31.7.1.
Install a dial indicator on the transmission (1).
31.7.2.
Install the backlash tool (205-040-300-1GIF-1) on the rotor brake disc. With the drive quill stationary, measure the
backlash of the rotor brake disc with the tool.
31.7.3.
If the tool is not available, measure the backlash tangentially at a distance of 1.421 inches (36.09 mm) out from
center of the rotor brake disc.
31.7.4.
The backlash limit for the rotor brake quill assembly 412-040-123-101 is 0.012 to 0.020 inch (0.30 to 0.51 mm).
31.7.5.
The backlash limit for the rotor brake quill assembly 412-040-123-103 is 0.010 to 0.020 inch (0.25 to 0.51 mm).
31.8.
Install the rotor brake disc (3) and brake assembly (3A) (BHT-412-MM).
NOTE
The following procedure applies if the rotor brake is not installed.
32.
Install the cover (not illustrated) on the rotor brake drive quill port as follows:
32.1.
Lubricate a new packing with the same oil used in the transmission and install the packing on the cover.
32.2.
Put the cover on the transmission main case.
32.3.
Install the six bolts with aluminum washers next to the cover and the steel washers next to the bolt heads. Torque the
bolts 160 to 190 inch-pounds (18 to 21 Nm).
33.
For transmission 412-040-002, check the backlash on the main input quill (6, Figure 4) as follows:
DO NOT ALTER SHIM PLATE ON MAIN CASE OR QUILL SLEEVE TO OBTAIN BACKLASH.
IF BACKLASH IS NOT WITHIN LIMITS, PARTS ARE IMPROPERLY ASSEMBLED OR ARE
DIMENSIONALLY INCORRECT.
33.1.
Remove the retaining ring (1, Figure 8), grease retainer (2), and lock spring (4).
33.2.
Install the backlash tool (212-040-001-19GIF-1) on the main input quill (5).
33.3.
If not previously accomplished, make the workaid for the dial indicator support (Figure 9).
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33.4.
Install the dial indicator support (Figure 9) on one of the main input quill studs. Install the dial indicator on the support
and put a dial indicator to contact the marked spot on the backlash tool.
33.5.
Take the backlash reading at three places 120° apart around the gear. Record the backlash values. The backlash
limit for the main input quill is 0.012 to 0.019 inch (0.31 to 0.48 mm) for the transmission 412-040-002.
NOTE
If the backlash tools previously listed are not available, other tools that can measure backlash at a
distance (radius) of 2.070 inches (52.58 mm) from the input quill gear center may be substituted.
Permitted backlash values are the same as stated in Step 33.5..
33.6.
Remove the backlash tools from the main input quill, but leave the tools installed in the main input gear quill.
33.7.
Install the lock spring (4, Figure 8). Make sure that the tang on the lock spring is fully seated in the groove.
33.8.
Lubricate and install the new packing (3) on the grease retainer (2).
33.9.
Install the grease retainer (2) and the retaining ring (1).
34.
For the transmission 412-040-004, check the backlash on the main input quill (6, Figure 4) as follows:
NOTE
Make sure that the ring gear (5, Figure 10) is installed prior to installation of the backlash tool set
412-240-006-101.
34.1.
Install the plate assembly 412-240-006-103 on the main input adapter, as shown in Figure 4.
34.2.
If not previously accomplished, make the workaid for the dial indicator support per Figure 9.
34.3.
Install the dial indicator support (Figure 9) on one of the main input quill studs. Install the dial indicator on the support
and put a dial indicator to contact the marked spot on the backlash tool.
DO NOT ALTER SHIM PLATE ON MAIN CASE OR QUILL SLEEVE TO OBTAIN BACKLASH.
IF BACKLASH IS NOT WITHIN LIMITS, PARTS ARE IMPROPERLY ASSEMBLED OR ARE
DIMENSIONALLY INCORRECT
34.4.
Take the backlash reading at three places 120° apart around the gear. Record the backlash values. The backlash
limit for the main input quill is 0.010 to 0.018 inch (0.25 to 0.46 mm) for the transmission 412-040-004.
34.5.
Remove the backlash tool plate assembly from the main quill adapter, but leave the tools installed on the ring
gear and the main input gear quill.
35.
Check the backlash on the hydraulic pump drive quill (4, Figure 7) as follows:
DO NOT ALTER SHIM PLATE ON MAIN CASE OR QUILL SLEEVE TO OBTAIN BACKLASH.
IF BACKLASH IS NOT WITHIN LIMITS, PARTS ARE IMPROPERLY ASSEMBLED OR ARE
DIMENSIONALLY INCORRECT.
35.1.
Install the backlash tool (212-040-001-3GIF-1), Detail 4 on the hydraulic pump drive quill (4).
35.2.
If not previously accomplished, make the workaid for the dial indicator support (Figure 9).
35.3.
Install the dial indicator support (Figure 9) on one of the hydraulic pump drive quill studs. Install the dial indicator on
the support and put a dial indicator to contact the dowel pin in the backlash tool.
35.4.
Take the backlash reading at three places 120° apart around the gear. Record the backlash values. The backlash
limit for the hydraulic pump drive quill is 0.010 to 0.018 inch (0.25 to 0.46 mm) for the transmissions 412-040-002.
A permitted backlash value for the hydraulic pump drive quill is 0.010 to 0.020 inch (0.25 to 0.51 mm) for the
transmissions 412-040-004.
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NOTE
If the backlash tools previously listed are not available, other tools that can measure backlash at a distance
(radius) of 1.774 inches (45.06 mm) from the hydraulic pump drive gear center may be substituted.
Permitted backlash values are the same as stated in Step 35.4..
35.5.
Remove the backlash tools from the hydraulic pump drive quill.
35.6.
Remove the backlash tools from the main input gear quill that were installed in Step 29..
36.
Verify the existence of backlash on the rotor brake drive quill if installed. A measurement is not required.
37.
Install the oil temperature manifold (14, Figure 11) and the oil jets as follows:
37.1.
Lubricate new packings (6 and 7) with the same oil used in the transmission and install the packings and the new
gasket (5) on the oil temperature manifold (14).
37.2.
Put the oil temperature manifold (14) on the main case and install the bracket (12) with the bolt (10) and the thin
steel washer (11). Torque the bolt 50 to 70 inch-pounds (5.65 to 7.91 Nm).
37.3.
Lubricate new packings (17 and 18) with the same oil used in the transmission and install the packings on the
oil jet No. 7 (13).
37.4.
Put the oil jet No. 7 (13) in the oil temperature manifold (14).
37.5.
Install the screw (20) and the steel washer (19). Tighten the screw.
37.6.
Install the new seal (16) and the screw (15). Tighten the screw.
37.7.
Secure the screw (15) to the screw (20) with lockwire (C-405).
37.8.
Lubricate new packings (9, 10, 11, Figure 12) with the same oil used in the transmission and install the packings
on the oil jet No. 3 (12).
37.9.
Put the oil jet No. 3 (12) in the manifold.
37.10.
Install the bracket (18) with the bolt (16) and the thin steel washer (17). Torque the bolt 50 to 70 inch-pounds
(5.65 to 7.91 Nm).
37.11.
Install the screw (15), new gasket (13), and thin steel washer (14). Tighten the screw.
37.12.
Secure the screw (15) to the bolt (16) with lockwire (C-405).
37.13.
Lubricate a new packing (11, Figure 13) with the same oil used in the transmission and install packing on the
thermostatic switch (12).
37.14.
Install the thermostatic switch (12) in the oil temperature manifold (8). Tighten the switch.
37.15.
Lubricate a new packing (9) with the same oil used in the transmission and install the packing on the pressure
regulating valve (10).
37.16.
Install the pressure regulating valve (10) in the oil temperature manifold (8). Torque the pressure regulating valve
150 to 180 inch-pounds (16.9 to 20.3 Nm).
37.17.
Secure the pressure regulating valve (10) to the thermostatic switch (12) with lockwire (C-405).
37.18.
Lubricate a new packing (8, Figure 11) with the same oil used in the transmission and install the packing on
the thermobulb (9).
37.19.
Install the thermobulb (9) in the oil temperature manifold (14). Torque the thermobulb 15 to 20 inch-pounds (1.69
to 2.25 Nm).
37.20.
Secure the thermobulb (9) to the pressure regulating valve (10, Figure 13) with lockwire (C-405).
NOTE
Refer to Figure 14, Detail A for a sectional view of the installed planetary gears, sun gears, and adapting
parts when accomplishing Step 38. through Step 42..
38.
Put the lower sun gear (14, Figure 14) on the main input gear quill shaft (16) with the longer inner shoulder down.
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39.
Assemble the lower bearing (12), outer liner (11), and inner liner (13) with the thrust (non-counterbored) side of the
outer race of the bearing against the shoulder in the outer liner until fully seated. Install the assembled parts on the
main input gear quill shaft (16) above the lower sun gear (14). Make sure that the bearing liner and sun gear are
positioned, as shown in the sectional view, Detail A.
40.
Install the lower planetary (10) with the pinions engaged with the lower sun gear (14). When the lower planetary is
properly installed, the splined section of the lower planetary will be seated on the flange of the outer liner (11). Only for
the lower planetary 204-040-784 with the spider 412-040-785 installed, the three equally spaced slots must engage
the three tangs of the liner and must be lined up with the three chamfered teeth on the lower side of the spider.
41.
Put the oil deflector (9) on the upper sun gear (7), as shown in the sectional view, Detail A. Install the retaining ring
(8). Make sure that the retaining ring is fully seated in the retaining ring groove.
42.
Put the assembled upper sun gear (7) and the oil deflector (9) into the lower planetary (10). Engage the notches in
the lower side of the sun gear with the tangs on the outer liner (11).
43.
Install the oil jet housing on the ring gear (5, Figure 10) as follows:
43.1.
Put the ring gear (5) on the work bench with the wider gear teeth up.
DO NOT ALLOW SEALANT COATED GASKETS TO COME IN CONTACT WITH TRANSMISSION OIL
FOR AT LEAST 24 HOURS AFTER SEALANT HAS BEEN APPLIED.
NOTE
Put the jets through the jet housings and the ring gear to ensure correct alignment during installation of
each jet housing.
43.2.
Locate the tooling hole on the lower flange of the ring gear (5). A second tooling hole may be located in the upper
flange.
43.3.
Clean the mating surfaces of the oil jet housing (32) and the ring gear (5) with MEK (C-309). Apply a thin coating of
sealant (C-308), 0.010 to 0.020 inch (0.25 to 0.51 mm) thick, to both sides of the new gasket (33). Apply sealant
(C-308) to the inside edges of the gasket holes with a cotton swab to ensure complete coverage.
43.4.
Put the new gasket (33) and the oil jet housing (32) on the ring gear (5) on the first set of holes counterclockwise from
the tooling hole(s), as shown inFigure 10.
43.5.
Install the bolts (28), with the thin steel washer (29) under the bolt heads, with the head outboard. Install the aluminum
washer (30) and the thin aluminum washer (31), as required, next to the oil jet housing (32) and one washer (27A)
and one thin steel washer (27) under the nuts (26). Torque the nuts 50 to 70 inch-pounds (5.65 to 7.91 Nm) and
secure with the new cotter pins (25).
NOTE
The procedures for the oil jet housing (34 and 39) are the same, therefore only the procedure for the oil
jet housing (39) is given.
43.6.
Put the new gasket (38) and the oil jet housing (39) on the ring gear (5) with the hole for the oil jet screw toward the oil
jet housing (32), as shown in Figure 10.
43.7.
Install the bolts (43) with the thin steel washer (42) under the bolt heads, with the heads outboard. Install the steel
washer (41) and the thin aluminum washers (40), as required, next to the oil jet housing (39). Install the washers
(37A) and the thin steel washers (37) under the nuts (36). Torque the nuts 50 to 70 inch-pounds (5.65 to 7.91 Nm)
and secure with the new cotter pins (35).
44.
Install the ring gear (5) as follows:
44.1.
Lubricate new packings (2 and 4, Figure 11) with the same oil used in the transmission and install the packings on
the oil transfer tube (3).
44.2.
Install the oil transfer tube (3) in the oil temperature manifold (14).
44.3.
Lubricate a new packing (10, Figure 10) with the same oil used in the transmission and install the packing on the
main input gear quill (11).
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NOTE
If a run-in test stand is available per BHT 77-003, it is permitted to omit sealant on the mating surface
until such time the qualification inspection is complete and ready for assembly.
44.4.
Apply a thin coat of sealant (C-328) to the mating flange of the ring gear and the main input gear quill.
44.5.
Put the ring gear (5) on the main input gear quill (11) with the oil jet housing (32) aligned with the tube installed
inStep 44.1. and carefully mesh the spline teeth. Insert the tube into the housing. Tap the ring gear with a rawhide or
a plastic mallet until fully seated.
44.6.
Put the neck and scupper support bracket (4) on the lower flange of the ring gear on the right side of the transmission.
The forward hole in the bracket must be positioned at the first hole in the ring gear (5) flange aft of the oil jet housing
(39). Install the four bolts (1), to secure the bracket to the transmission with the thin steel washer (2) under the bolt
head, the washer (3) next to the bracket, the washer (24) next to the main case and the thin steel washer (23)
with the nut (22). Do not torque the nut at this time.
44.7.
Put the bracket (7) on the lower flange of the ring gear (5) at the first hole aft of the planetary electrical chip detector
(20). Install the bolt (6), washers (19 and 18), and nut (17). Do not torque the nut at this time.
44.8.
Install the four additional brackets (7) and the bolts at the alternate holes on the left side of the ring gear in the
same manner as outlined in the preceding step. The five brackets will support the electrical wiring from above and
slightly right of the center of the main input quill, around the left side of the ring gear, to the planetary electrical
chip detector (20).
44.9.
Install the 11 bolts (8), washers (9, 14, and 15), and nuts (16) in the remaining holes in the ring gear (5) lower flange.
Torque the nuts (16, 17, and 22) 230 to 250 inch-pounds (25.99 to 28.25 Nm).
45.
Assemble the upper bearing (5, Figure 14), outer liner (6), mast driving adapter (3), and extension (4), if applicable,
with the thrust (non-counterbored) side of the bearing outer race against the shoulder in the outer liner. Insert these
parts from the lower side of the upper planetary (2) and install the retaining ring (1). Make sure that the retaining
ring is fully seated.
NOTE
To help the installation, use two jacking screw set (T102064) installed at opposite sides on the upper
planetary (2).
46.
Install the upper planetary (2) in the ring gear (15) with pinion teeth engaged in the ring gear and the upper sun gear
(7). Engage projections on the outer liner (6) with the notches in the outer liner (11). The upper bearing (5) and
the lower bearing (12) should now be back-to-back.
47.
Spray the inside of the transmission with the same oil used in the transmission.
48.
Install the top case (20, Figure 15) as follows:
48.1.
Lubricate new packings (12 and 14) with the same oil used in the transmission and install on the oil transfer tube (13).
Insert the tube into the oil jet housing installed on the ring gear (11) in Step 43..
48.2.
Lubricate a new packing (17) with the same oil used in the transmission and install on the top case (20).
48.3.
Put the top case (20) on the ring gear (11) and simultaneously insert the oil transfer tube (13) into the port on the top
case. Tap the top case lightly with a rawhide or plastic mallet to seat the top case on the ring gear.
48.4.
Install the bolt (3), thin steel washer (4), and bracket (5) at the first hole aft of the port for the upper mast electrical
chip detector (1). Install the steel washer (7) and the nut (8). Do not torque the nut at this time.
48.5.
Install the 15 bolts (21), washers (16, 15, and 10), and nuts (9). Torque the nuts (8 and 9) 230 to 250 inch-pounds (26
to 28 Nm).
48.6.
Measure the distance from the top of the mast driving adapter (3, Figure 16) to the top of the top case as illustrated. If
the dimension is less than 2.226 inches (56.54 mm), the transmission is not assembled properly. Inspect the outer
liners (6 and 11, Figure 14) to ensure that the projections on the outer liner (6) are engaged with the notches in
the outer liner (11).
48.7.
Install the cover and lift plate assembly (T103211-101) on the top case (20, Figure 15).
48.8.
Install the three screws (19) and the aluminum washers (18). Secure the screws to the adjacent holes in the top
case with lockwire (C-405).
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48.9.
Install the upper mast electrical chip detector (1) and the new packing (2). Torque the chip detector 30 to 108
inch-pounds (3.4 to 12.2 Nm). Secure the chip detector at the hole in the top case adjacent to the port for the
mast withlockwire (C-405).
49.
Install the accessory and tail rotor drive and sump assembly (7, Figure 6) as follows:
49.1.
If the transmission is supported on the transportation stand, as illustrated in Figure 2, hoist the transmission clear of
the stand and proceed to Step 49.3..
49.2.
If the transmission is supported on the transmission stand, as illustrated in Figure 1, rotate the transmission 90°
to the horizontal position.
49.3.
Put the tail rotor drive quill adapter (2, Figure 6) in the accessory drive quill in the support case (1).
49.4.
Put the new gasket (3) on the support case (1).
49.5.
Put the accessory and tail rotor drive and sump assembly (7) on the support case (1) with the tail rotor drive quill
on the aft side of the case. Secure the sump with aluminum washers (4) next to the sump, thin steel washers (5),
and nuts (6) on each of the 13 studs with one exception; omit the aluminum washer and install the bracket (10),
thin steel washer (9), and nut (8), on the stud directly above the magnetic chip detector in the sump. Torque the
nuts (6 and 8) 50 to 70 inch-pounds (5.65 to 7.91 Nm).
49.6.
Put the lift link fitting (14) on the support case (1) as illustrated. Install the four steel washers (13), nuts (12). Torque
the nuts 37 to 42 foot-pounds (50.16 to 56.94 Nm) for the transmission 412-040-002. Torque the nuts 40 to 58
foot-pounds (54.23 to 78.64 Nm) for the transmissions 412-040-004. Secure the nuts with new cotter pins (11).
49.7.
If the transmission is to be supported on the transportation stand illustrated in Figure 2, install the transmission in
the stand. If the transmission is supported in the transmission stand illustrated in Figure 1, rotate the transmission
90° to the vertical position.
50.
Install the plug (1, Figure 17) and the new packing (2). Torque the plug 80 to 120 inch-pounds (9.04 to 13.56 Nm).
Secure the plug to the hole in the top case adjacent to the port for the mast with lockwire (C-405).
51.
Put the spacer (22, Figure 11) and the oil pressure manifold (23) on the transmission. Install the aluminum washer
(24), steel washer (25), and nut (26) in two places. Torque the nuts 50 to 70 inch-pounds (5.65 to 7.91 Nm).
52.
Apply the same oil used in the transmission to the threads of the union (27) and the new packing (28). Install the
union and the packing in the oil pressure manifold (23). Tighten the union.
53.
Apply the same oil used in the transmission to the threads of the elbow and new packing (5, Figure 17). Install the
elbow and packing (5) and the nut (6) in the oil pressure manifold (23, Figure 11), but do not torque the nut at this time.
54.
Apply the same oil used in the transmission to the threads of the banjo bolt (20, Figure 17) and the two new packings
on the elbow and two packings (19). Put the elbow on the transmission with one packing next to the transmission and
one packing on top of the elbow. Install the banjo bolt, but do not torque at this time.
55.
Apply the same oil used in the transmission to the threads of the elbow and the new packing on the elbow and
packing (5). Install the tube (4). Tighten the nut (6) and the banjo bolt (20). Torque banjo bolt 40 to 65 inch-pounds
(4.5 to 7.3 Nm).
56.
Lubricate new packings (31 and 32, Figure 12) with the same oil used in the transmission and install the packings on
the oil jet No. 1 (30). Put the jet in the transmission (40). Install the screw (26). Install the screw (27), thin steel
washer (28), and new gasket (29). Secure the screws (26 and 27) together withlockwire (C-405).
57.
Lubricate new packings (19 and 20) with the same oil used in the transmission and install the new packings on the oil
jet No. 2 (21). Put the jet in the transmission. Install the screw (25). Install the screw (24), thin steel washer (23), and
new gasket (22). Secure the screws (24 and 25) together with lockwire (C-405).
58.
Lubricate new packings (1, 2, and 3) with the same oil used in the transmission and install the packings on the oil jet
No. 6 (8). Put the jet in the transmission. Install the screw (7). Install the screw (6), new gasket (4), and thin steel
washer (5). Secure the screws together with lockwire (C-405).
59.
Put the auxiliary oil jet (48) and the new packing (47) in the jet housing on the ring gear. Install the screw (49). Coat
the threads of the elbow (52) and the new packing (50) with the same oil used in the transmission. Install the nut (51),
packing (50), and elbow (52) in the auxiliary oil jet. Do not tighten the nut at this time.
60.
Coat the threads of the elbow (17 and 8, Figure 17) and the threads on the nuts at both ends of the tubes (18 and
7) with the same oil used in the transmission. Install the elbows, new packing (15 and 10), nuts (16 and 9) in the
jet housing (14). Do not tighten the nuts at this time.
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61.
Install the tube (18) on the elbow (17). Install the opposite end of the tube on the elbow (52, Figure 12). Tighten
the nuts on both elbows.
62.
Install the auxiliary oil jet (42) and the tube (7, Figure 17) in the same manner as outlined in Step 60., Step 61.,
and Step 62..
63.
Secure the screw (43, Figure 12) to the elbow (46) with lockwire (C-405).
64.
Secure the screw (49) to the elbow (52) with lockwire (C-405).
65.
Lubricate new packing (3, Figure 13) with the same oil used in the transmission and install the packings on the
union (4).
66.
Install the union (4) on the oil pressure manifold (1). Tighten the union.
67.
Install the oil pressure switch (7) and the new packing (6) on the union (4). Torque the oil pressure switch 50 to 65
inch-pounds (5.65 to 7.34 Nm).
68.
Secure the oil pressure switch (7) to the oil pressure manifold (1) with lockwire (C-405).
69.
Install the oil pressure transmitter (5) and the new packing (2). Torque the oil pressure transmitter 50 to 65
inch-pounds (5.65 to 7.34 Nm).
70.
Secure the oil pressure transmitter (5) to the oil pressure manifold (1) with lockwire (C-405).
71.
Lubricate new packings (37 and 38, Figure 12) with the same oil used in the transmission and install the packings on
the oil jet No. 5 (36). Put the jet in the transmission and install the screw (39). Install the screw (33) with the thin steel
washer (34) and the new gasket (35). Secure the screws (33 and 39) together with lockwire (C-405).
72.
Lubricate the new packing (21, Figure 3) with the same oil used in the transmission and install the planetary electrical
chip detector (20) and the packing. Torque the chip detector 30 to 108 inch-pounds (3.4 to 12.2 Nm). Secure the chip
detector to the adjacent hole in the case with lockwire (C-405).
73.
Lubricate a new packing with the same oil used in the transmission and install the union and packing (25, Figure 18)
on the neck and scupper assembly (1). Tighten the union.
74.
Put the neck and scupper assembly (1) in position on the neck and scupper support bracket (2) with the union and
packing (25) facing aft.
75.
Install the neck and scupper assembly (1) on the neck and scupper support bracket (2) with four washers (24)
between the scupper and the bracket. Install the washers (23) and the nuts (22) on the scupper at four places,
securing the scupper to the bracket. Torque the nuts 50 to 70 inch-pounds (5.65 to 7.91 Nm).
76.
Coat the threads of the elbow and new packing (19) with the same oil used in the transmission. Install the elbow and
packing and the nut (21).
77.
Install the hose assembly (11) on the elbow and packing (19) and tighten the nuts (10 and 21).
78.
Install the new clamps (15) with the screws (16), washers (13), and nuts (12). Tighten the nuts.
79.
Put the tube (17) on the transmission and attach the nut (20) to the union and new packing (25). Put the opposite end
of the tube to drain into the scupper adjacent to the internal oil filter on the transmission sump. Tighten the nut.
80.
Install the screw (18), washer (28), and nut (29) to secure the new clamp (14) to the bracket (8). Tighten the nut.
81.
If applicable, remove the cap from the neck and scupper assembly (1).
82.
Install the filler oil cap adapter (9) as follows:
82.1.
If a new filler adapter (30) is installed on the transmission support case, remove and discard the existing safety chain.
82.2.
Apply wet zinc chromate primer (C-201) to the threads of the filler adapter (30).
82.3.
Install the filler adapter (30) into the transmission support case (Figure 18). Hand tighten the adapter.
NOTE
In order to lock the filler oil cap adapter (9) from the inside, fabricate a workaid that will simulate a filler
cap assembly.
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82.4.
Install the filler oil cap adapter (9) on the filler adapter (30). Tighten the filler oil cap adapter.
83.
Apply the same oil used in the transmission to the threads of the elbow (5), new packing (3), and tube (7).
84.
Install the elbow (5), nut (4), and new packing (3) on the neck and scupper assembly (1). Tighten the nut.
85.
Install the tube (7) on the elbow (5) and the extension cap (9). Tighten the nuts (6).
86.
If previously removed, install the cap on the neck and scupper assembly (1). Tighten the cap.
87.
Clamp the lower end of the tube (17) to the bracket (10, Figure 6).
88.
Install the transmission electrical cable assembly (22, Figure 19) as follows:
88.1.
Put the transmission electrical cable assembly (22) on the transmission (1).
88.2.
Stow the electrical connector (24P3) (24).
88.3.
Connect the electrical terminal and nipple (14) to the upper mast electrical chip detector (15). Do not overtorque
the terminal stud nut on the electrical chip detector.
88.4.
Connect the electrical terminal and nipple (19) to the planetary electrical chip detector (18). Do not overtorque
the terminal stud nut on the electrical chip detector.
88.5.
Connect the electrical connector (17) to the rotor tachometer generator (16).
88.6.
Connect the electrical terminal and nipple (13) to the oil thermostatic switch (12). Do not exceed 6 inch-pounds
(0.68 Nm) torque on the terminal stud nut.
88.7.
Connect the electrical connector (5) to the oil pressure switch (4).
88.8.
Connect the electrical connector (3) to the oil pressure transmitter (2).
88.9.
Connect the electrical connector (7) to the oil temperature transmitter (8).
88.10.
Connect the electrical terminal and nipple (11) to the sump electrical chip detector (10). Make drip loop in wire,
as shown in Figure 19.
88.11.
Connect the four wirings for rotor brake (20) to the rotor brake, as shown in Detail B. If the rotor brake is not installed,
stow the wiring for the rotor brake.
88.12.
Connect the three or four ground wires (23), as applicable, to the bracket (31) with the screw (30), aluminum washers
(27, 28, and 29), lockwasher (26), and nut (25). Tighten the nut.
NOTE
If the transmission with a full flow debris monitor is installed, perform Step 88.13..
88.13.
Connect the electrical terminal and nipple (11B) to the full flow debris monitor (11A).
88.14.
Secure the clamps (21) to the brackets (7, Figure 10) and all other similar brackets on the transmission.
89.
Cap or plug all open hoses and ports to prevent the entry of foreign materials.
90.
Run-in and test the transmission (412-A-63-10-00-06A-320A-B / 00134).
91.
Apply sealant and paint the transmission (412-A-63-10-00-06A-257A-B / 00135).
412-A-63-10-00-06A-710A-B
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ICN-412-A-631000-B-97499-00090-A-001-01
Figure 1. Transmission Assembly Stand - Application (Sheet 1 of 1)
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ICN-412-A-631000-B-97499-00091-A-001-01
Figure 2. Transmission Maintenance Transportation Stand - Application (Sheet 1 of 1)
412-A-63-10-00-06A-710A-B
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ICN-412-A-631000-B-97499-00106-A-002-01
Figure 3. Main Input Gear Quill and Main Case - Installation (Sheet 1 of 1)
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28 OCT 2024 Page 00133-15
BHT-412-CRO
ICN-412-A-631000-B-97499-00104-A-001-01
Figure 4. Main Input Quill - Installation (Typical) (Sheet 1 of 2)
412-A-63-10-00-06A-710A-B
Applicable to: ALL
Page 00133-16 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00105-A-001-01
Figure 4. Main Input Quill - Installation (Typical) (Sheet 2 of 2)
Applicable to: ALL
412-A-63-10-00-06A-710A-B
ECCN EAR99
28 OCT 2024 Page 00133-17
BHT-412-CRO
ICN-412-A-631000-B-97499-00116-A-001-01
Figure 5. Pusher Set (T101586) - Application (Sheet 1 of 1)
412-A-63-10-00-06A-710A-B
Applicable to: ALL
Page 00133-18 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00039-A-001-01
Figure 6. Accessory and Tail Rotor Drive and Sump - Installation (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-06A-710A-B
ECCN EAR99
28 OCT 2024 Page 00133-19
BHT-412-CRO
ICN-412-A-631000-B-97499-00103-A-001-01
Figure 7. SYS 2 Hydraulic Pump and Rotor Brake Drive Quill - Installation (Sheet 1 of 1)
412-A-63-10-00-06A-710A-B
Applicable to: ALL
Page 00133-20 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00117-A-001-01
Figure 8. Main Input Quill Grease Retainer - Installation (Typical) (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-06A-710A-B
ECCN EAR99
28 OCT 2024 Page 00133-21
BHT-412-CRO
ICN-412-A-631000-B-97499-00118-A-001-01
Figure 9. Dial Indicator Support Workaid (Sheet 1 of 1)
412-A-63-10-00-06A-710A-B
Applicable to: ALL
Page 00133-22 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00037-A-001-01
Figure 10. Ring Gear and Jet Housing - Installation (Sheet 1 of 2)
Applicable to: ALL
412-A-63-10-00-06A-710A-B
ECCN EAR99
28 OCT 2024 Page 00133-23
BHT-412-CRO
ICN-412-A-631000-B-97499-00038-A-001-01
Figure 10. Ring Gear and Jet Housing - Installation (Sheet 2 of 2)
412-A-63-10-00-06A-710A-B
Applicable to: ALL
Page 00133-24 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00100-A-001-01
Figure 11. Oil Temperature and Oil Pressure Manifolds - Installation (Sheet 1 of 2)
Applicable to: ALL
412-A-63-10-00-06A-710A-B
ECCN EAR99
28 OCT 2024 Page 00133-25
BHT-412-CRO
ICN-412-A-631000-B-97499-00101-A-001-01
Figure 11. Oil Temperature and Oil Pressure Manifolds - Installation (Sheet 2 of 2)
412-A-63-10-00-06A-710A-B
Applicable to: ALL
Page 00133-26 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00098-A-001-01
Figure 12. Oil Jets No. 1, No. 2, No. 3, No. 5, and Planetary Jet - Installation (Sheet 1 of 2)
Applicable to: ALL
412-A-63-10-00-06A-710A-B
ECCN EAR99
28 OCT 2024 Page 00133-27
BHT-412-CRO
ICN-412-A-631000-B-97499-00099-A-001-01
Figure 12. Oil Jets No. 1, No. 2, No. 3, No. 5, and Planetary Jet - Installation (Sheet 2 of 2)
412-A-63-10-00-06A-710A-B
Applicable to: ALL
Page 00133-28 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00097-A-001-01
Figure 13. Oil Pressure and Temperature Regulating and Indicating Components - Installation (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-06A-710A-B
ECCN EAR99
28 OCT 2024 Page 00133-29
BHT-412-CRO
ICN-412-A-631000-B-97499-00035-A-001-01
Figure 14. Upper and Lower Planetary - Installation (Sheet 1 of 2)
412-A-63-10-00-06A-710A-B
Applicable to: ALL
Page 00133-30 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00036-A-001-01
Figure 14. Upper and Lower Planetary - Installation (Sheet 2 of 2)
Applicable to: ALL
412-A-63-10-00-06A-710A-B
ECCN EAR99
28 OCT 2024 Page 00133-31
BHT-412-CRO
ICN-412-A-631000-B-97499-00102-A-001-01
Figure 15. Top Case - Installation (Sheet 1 of 2)
412-A-63-10-00-06A-710A-B
Applicable to: ALL
Page 00133-32 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-01030-A-001-01
Figure 15. Top Case - Installation (Sheet 2 of 2)
Applicable to: ALL
412-A-63-10-00-06A-710A-B
ECCN EAR99
28 OCT 2024 Page 00133-33
BHT-412-CRO
ICN-412-A-631000-B-97499-00119-A-001-01
Figure 16. Mast Driving Adapter To Transmission Top Case - Dimension Requirements (Sheet 1 of 1)
412-A-63-10-00-06A-710A-B
Applicable to: ALL
Page 00133-34 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00096-A-001-01
Figure 17. Breather and Planetary Oil Jet Tubes - Installation (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-06A-710A-B
ECCN EAR99
28 OCT 2024 Page 00133-35
BHT-412-CRO
ICN-412-A-631000-B-97499-00094-A-001-01
Figure 18. Neck, Scupper, and External Oil Hoses - Installation (Sheet 1 of 2)
412-A-63-10-00-06A-710A-B
Applicable to: ALL
Page 00133-36 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00095-A-001-01
Figure 18. Neck, Scupper, and External Oil Hoses - Installation (Sheet 2 of 2)
Applicable to: ALL
412-A-63-10-00-06A-710A-B
ECCN EAR99
28 OCT 2024 Page 00133-37
BHT-412-CRO
ICN-412-A-631000-B-97499-00092-A-001-01
Figure 19. Transmission Electrical Cable - Installation (Sheet 1 of 2)
412-A-63-10-00-06A-710A-B
Applicable to: ALL
Page 00133-38 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00093-A-001-01
Figure 19. Transmission Electrical Cable - Installation (Sheet 2 of 2)
Applicable to: ALL
412-A-63-10-00-06A-710A-B
ECCN EAR99
28 OCT 2024 Page 00133-39
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-06A-710A-B
Applicable to: ALL
Page 00133-40 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Transmission - Run-in and Test
Procedure
1.
If a run-in stand is available, run-in and test the transmission in accordance with the BHT-PUB 77-003, Run-In
and Test Manual.
2.
If a run-in stand is not available, use an alternate Run-In and Test Procedure outlined in the BHT-412-MM-6. This is
the minimum acceptable test for an overhauled transmission.
Applicable to: ALL
412-A-63-10-00-06A-320A-B
ECCN EAR99
31 MAY 2023 Page 00134-1
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-06A-320A-B
Applicable to: ALL
Page 00134-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Transmission - Sealing and Painting
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Chromic acid treatment
Epoxy polyamide primer
Polyurethane coating
Aliphatic naphtha
Cheesecloth
C-103
C-204
C-245
C-305
C-486
AR
AR
AR
AR
AR
Remarks
Procedure
NOTE
Make sure that the transmission is assembled and has been run-in and tested prior to sealing and painting
(412-A-63-10-00-06A-320A-B / 00134).
1.
Apply sealing compound and sealant prior to painting the transmission.
2.
Install the protective covers at the following locations:
2.1.
Tachometer generator mounting flange.
2.2.
Hydraulic pump mounting flange adjacent to the tachometer generator.
2.3.
Hydraulic pump mounting flange on the main case.
2.4.
Rotor brake quill on the main case.
2.5.
Port in the main case on the right side opposite the rotor brake quill.
3.
Remove the external lines and hoses to facilitate painting. Cap or plug all openings.
4.
Touch up areas on the magnesium cases where chemical film has been removed with chromic acid treatment (C-103)
(BHT-ALL-SPM, Chapter 3, Standard Practices Manual).
5.
Mask the transmission for primer and paint.
6.
Clean the areas of the transmission that are to be painted with clean cheesecloth (C-486) moistened with aliphatic
naphtha (C-305). Wipe dry with a clean cheesecloth before naphtha evaporates.
7.
Apply one coat of epoxy polyamide primer (C-204) to 5 to 8 mil thickness (BHT-ALL-SPM, Chapter 4, Standard
Practices Manual).
8.
Apply a coat of polyurethane coating (C-245) not less than 30 minutes and not more than 4 hours after the epoxy
primer is applied (color No. 36440 per FED-STD-595) (BHT-ALL-SPM, Chapter 4, Standard Practices Manual).
9.
Install the SERVICE TRANSMISSION decal on the main support case below and to the left of the oil filler cap to
indicate the type of oil to be used.
10.
Identify the transmission by the part number on the top case. Use stamp ink or stencil.
11.
Install the hoses and the lines removed in Step 3..
Applicable to: ALL
412-A-63-10-00-06A-257A-B
ECCN EAR99
31 MAY 2023 Page 00135-1
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-06A-257A-B
Applicable to: ALL
Page 00135-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Transmission Case - General
This section contains instructions to overhaul the top case, main bevel gear case, and main support case.
Applicable to: ALL
412-A-63-10-00-00A-028A-B
ECCN EAR99
31 MAY 2023 Page 00136-1
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-00A-028A-B
Applicable to: ALL
Page 00136-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Transmission Top Case (212-040-059-101) - Disassembly
Procedure
1.
Remove the cotter pins (5, Figure 1), nuts (4), washers (3), and collector (2) from top case (1). Discard the cotter pins.
Applicable to: ALL
412-A-63-10-00-08A-530A-B
ECCN EAR99
31 MAY 2023 Page 00137-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00120-A-001-01
Figure 1. Transmission Top Case (Sheet 1 of 1)
412-A-63-10-00-08A-530A-B
Applicable to: ALL
Page 00137-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Transmission Top Case (212-040-059-101) - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Chromic acid treatment
Drycleaning solvent
Solvent
Paint remover
Clean cloth
C-103
C-304
C-334
C-436
C-516
AR
AR
AR
AR
AR
Remarks
Procedure
1.
Clean all the parts with drycleaning solvent (C-304). Use soft bristle brush to dislodge stubborn deposits. All parts
may be cleaned with solvent (C-334) by vapor degreasing if desired.
2.
Dry the parts with a clean cloth (C-516) or dry filtered compressed air.
3.
Remove the sealant with a plastic scraper.
4.
Remove the paint with paint remover (C-436). Rinse with water and dry with filtered compressed air.
5.
If the top case is corroded, remove the corrosion by chromic acid treatment (C-103) pickle process for cleaning
magnesium parts (BHT-ALL-SPM, Standard Practices Manual).
Applicable to: ALL
412-A-63-10-00-08A-258A-B
ECCN EAR99
31 MAY 2023 Page 00138-1
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-08A-258A-B
Applicable to: ALL
Page 00138-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Transmission Top Case (212-040-059-101) - Inspection
Procedure
1.
Inspect the top case (1, Figure 1) for yielding and the stud threads for damage and looseness.
2.
Inspect the top case (1) for corrosion and damage in accordance with Figure 2.
3.
Inspect the top case (1, Figure 1) by fluorescent penetrant method (BHT-ALL-SPM, Standard Practices Manual).
Applicable to: ALL
412-A-63-10-00-08A-280A-B
ECCN EAR99
31 MAY 2023 Page 00139-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00120-A-001-01
Figure 1. Transmission Top Case (Sheet 1 of 1)
412-A-63-10-00-08A-280A-B
Applicable to: ALL
Page 00139-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00121-A-001-01
Figure 2. Transmission Top Case - Damage Limits and Repair (Sheet 1 of 7)
Applicable to: ALL
412-A-63-10-00-08A-280A-B
ECCN EAR99
31 MAY 2023 Page 00139-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00122-A-001-01
Figure 2. Transmission Top Case - Damage Limits and Repair (Sheet 2 of 7)
412-A-63-10-00-08A-280A-B
Applicable to: ALL
Page 00139-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00123-A-001-01
Figure 2. Transmission Top Case - Damage Limits and Repair (Sheet 3 of 7)
Applicable to: ALL
412-A-63-10-00-08A-280A-B
ECCN EAR99
31 MAY 2023 Page 00139-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00124-A-001-01
Figure 2. Transmission Top Case - Damage Limits and Repair (Sheet 4 of 7)
412-A-63-10-00-08A-280A-B
Applicable to: ALL
Page 00139-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00126-A-001-01
Figure 2. Transmission Top Case - Damage Limits and Repair (Sheet 5 of 7)
Applicable to: ALL
412-A-63-10-00-08A-280A-B
ECCN EAR99
31 MAY 2023 Page 00139-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00127-A-001-01
Figure 2. Transmission Top Case - Damage Limits and Repair (Sheet 6 of 7)
412-A-63-10-00-08A-280A-B
Applicable to: ALL
Page 00139-8 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00128-A-001-01
Figure 2. Transmission Top Case - Damage Limits and Repair (Sheet 7 of 7)
Applicable to: ALL
412-A-63-10-00-08A-280A-B
ECCN EAR99
31 MAY 2023 Page 00139-9
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-08A-280A-B
Applicable to: ALL
Page 00139-10 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Transmission Top Case (212-040-059-101) - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Chemical film material
Sealant
C-100
C-308
AR
AR
Remarks
Procedure
1.
Replace loose or damaged threaded inserts with new threaded inserts (BHT-ALL-SPM, Standard Practices Manual).
2.
If the top case is corroded in the area adjacent to the studs or if the studs are corroded, rework as follows:
NOTE
When corrosion has not penetrated past the first thread, rework as outlined in Step 2.1. through Step 2.4..
2.1.
Measure and record the height of the stud.
2.2.
Remove the stud from the corrosion damaged area.
2.3.
If the corrosion has affected more than one complete thread, the case is non-airworthy and nonrepairable.
2.4.
If the corrosion has affected less than one complete thread, rework case as follows:
2.4.1.
In Area T (Figure 1, Section A-A), counter drill stud holes 0.327 to 0.334 inch (8.31 to 8.48 mm) in diameter and a
maximum depth of 0.110 inch (2.79 mm). Break all sharp edges, except in the threaded area.
2.4.2.
In Area L (Figure 1, Section J-J), counter drill stud holes 0.327 to 0.334 inch (8.31 to 8.48 mm) in diameter and a
maximum depth of 0.110 inch (2.794 mm). Break all sharp edges, except in the threaded area.
2.4.3.
After drilling, treat the surfaces with magnesium alloy chromic acid brush-on treatment (BHT-ALL-SPM, Standard
Practices Manual).
2.4.4.
Install a new stud in reworked hole. Use wet primer on mating parts. Torque the stud 100 to 130 inch-pounds (11
to 14 Nm).
2.4.5.
Fill the counterdrilled holes with sealant (C-308) flush with the top case.
3.
Touch up all areas on the case where chemical film has been removed with chemical film material (C-100) for the
aluminum brush-on treatment (BHT-ALL-SPM, Standard Practices Manual).
Applicable to: ALL
412-A-63-10-00-08A-685A-B
ECCN EAR99
31 MAY 2023 Page 00140-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00121-A-001-01
Figure 1. Transmission Top Case - Damage Limits and Repair (Sheet 1 of 7)
412-A-63-10-00-08A-685A-B
Applicable to: ALL
Page 00140-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00122-A-001-01
Figure 1. Transmission Top Case - Damage Limits and Repair (Sheet 2 of 7)
Applicable to: ALL
412-A-63-10-00-08A-685A-B
ECCN EAR99
31 MAY 2023 Page 00140-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00123-A-001-01
Figure 1. Transmission Top Case - Damage Limits and Repair (Sheet 3 of 7)
412-A-63-10-00-08A-685A-B
Applicable to: ALL
Page 00140-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00124-A-001-01
Figure 1. Transmission Top Case - Damage Limits and Repair (Sheet 4 of 7)
Applicable to: ALL
412-A-63-10-00-08A-685A-B
ECCN EAR99
31 MAY 2023 Page 00140-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00126-A-001-01
Figure 1. Transmission Top Case - Damage Limits and Repair (Sheet 5 of 7)
412-A-63-10-00-08A-685A-B
Applicable to: ALL
Page 00140-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00127-A-001-01
Figure 1. Transmission Top Case - Damage Limits and Repair (Sheet 6 of 7)
Applicable to: ALL
412-A-63-10-00-08A-685A-B
ECCN EAR99
31 MAY 2023 Page 00140-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00128-A-001-01
Figure 1. Transmission Top Case - Damage Limits and Repair (Sheet 7 of 7)
412-A-63-10-00-08A-685A-B
Applicable to: ALL
Page 00140-8 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Transmission Top Case (212-040-059-101) - Assembly
Procedure
1.
Install the collector (2, Figure 1) on the top case (1) with the washers (3) and the nuts (4).
2.
Torque the nuts (4) 12 to 15 inch-pounds (1.36 to 1.69 Nm). Safety the nuts with new cotter pins (5).
Applicable to: ALL
412-A-63-10-00-08A-710A-B
ECCN EAR99
31 MAY 2023 Page 00141-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00120-A-001-01
Figure 1. Transmission Top Case (Sheet 1 of 1)
412-A-63-10-00-08A-710A-B
Applicable to: ALL
Page 00141-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Transmission Main Bevel Gear Case (212-040-053-009) - Disassembly
Procedure
1.
If not previously accomplished, remove the retaining ring (4, Figure 1) and the input pinion bearing (3).
2.
If not previously accomplished, remove the retaining ring (19) and the input gear shaft bearing (20).
3.
Remove the screws (29) and the shim plate set (1). Mark the shim plate set for installation at the same location
on the same case.
4.
Remove the screws (5) and shim plate (7). Mark the shim plate for installation at the same location on the same case.
5.
Remove the screws (15) and shim plate (16). Mark the shim plate for installation at the same location on the same
case.
6.
Remove the screws (22) and shim plate (21). Mark the shim plate for installation at the same location on the same
case.
7.
Remove the screws (26) and shim plate (25). Mark the shim plate for installation at the same location on the same
case.
Applicable to: ALL
412-A-63-10-00-09A-530A-B
ECCN EAR99
31 MAY 2023 Page 00142-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00129-A-001-01
Figure 1. Transmission Main Case (Sheet 1 of 1)
412-A-63-10-00-09A-530A-B
Applicable to: ALL
Page 00142-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Transmission Main Bevel Gear Case (212-040-053-009) - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Chromic acid treatment
Drycleaning solvent
Paint remover
C-103
C-304
C-436
AR
AR
AR
Remarks
Procedure
1.
Prior to cleaning, Inspect the Area J (Figure 1) and all the studs in the case for corrosion. Refer to Figure 1 for
the inspection procedure.
2.
Clean the main bevel gear case with drycleaning solvent (C-304) and dry with filtered compressed air.
3.
Remove the sealant with a plastic scraper.
4.
Remove the paint with paint remover (C-436). Rinse with water and dry with filtered compressed air.
5.
If the main bevel gear case is corroded, remove corrosion by chromic acid treatment (C-103) pickle process for
cleaning magnesium parts (BHT-ALL-SPM, Standard Practices Manual).
Applicable to: ALL
412-A-63-10-00-09A-258A-B
ECCN EAR99
31 MAY 2023 Page 00143-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00130-A-001-01
Figure 1. Main Bevel Gear Case - Damage Limits (Sheet 1 of 3)
412-A-63-10-00-09A-258A-B
Applicable to: ALL
Page 00143-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00131-A-001-01
Figure 1. Main Bevel Gear Case - Damage Limits (Sheet 2 of 3)
Applicable to: ALL
412-A-63-10-00-09A-258A-B
ECCN EAR99
31 MAY 2023 Page 00143-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00132-A-001-01
Figure 1. Main Bevel Gear Case - Damage Limits (Sheet 3 of 3)
412-A-63-10-00-09A-258A-B
Applicable to: ALL
Page 00143-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Transmission Main Bevel Gear Case (212-040-053-009) - Inspection
Procedure
1.
Inspect the main bevel gear case by fluorescent penetrant method (BHT-ALL-SPM, Standard Practices Manual).
2.
Inspect the main bevel gear case in accordance with Figure 1.
Applicable to: ALL
412-A-63-10-00-09A-280A-B
ECCN EAR99
31 MAY 2023 Page 00144-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00130-A-001-01
Figure 1. Main Bevel Gear Case - Damage Limits (Sheet 1 of 3)
412-A-63-10-00-09A-280A-B
Applicable to: ALL
Page 00144-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00131-A-001-01
Figure 1. Main Bevel Gear Case - Damage Limits (Sheet 2 of 3)
Applicable to: ALL
412-A-63-10-00-09A-280A-B
ECCN EAR99
31 MAY 2023 Page 00144-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00132-A-001-01
Figure 1. Main Bevel Gear Case - Damage Limits (Sheet 3 of 3)
412-A-63-10-00-09A-280A-B
Applicable to: ALL
Page 00144-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Transmission Main Bevel Gear Case (212-040-053-009) - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Chemical film material
Sealant
Adhesive
Abrasive cloth or paper
C-100
C-308
C-363
C-406
AR
AR
AR
AR
Remarks
Procedure
1.
Replace loose or damaged threaded inserts (BHT-ALL-SPM, Standard Practices Manual).
2.
Replace loose or missing washer seats.
3.
If the main bevel gear case is corroded in the area adjacent to the studs, or if the studs are corroded, rework as follows:
3.1.
Measure and record the height of the stud.
3.2.
Remove the stud from the corrosion damaged area. If a stud is removed below the input quill bore, also remove
the filler from the top of the hole.
3.3.
If the corrosion has affected more than one complete thread, the case is non-airworthy and nonrepairable.
3.4.
If the corrosion has affected less than one complete thread, rework the case as follows:
3.4.1.
Counter drill the stud holes 0.452 to 0.459 inch (11.48 to 11.66 mm) in diameter and a maximum depth of 0.156 inch
(3.96 mm). Break all sharp edges, except in the threaded area.
3.4.2.
After drilling, treat surfaces with chemical film material (C-100) for aluminum brush-on treatment
(BHT-ALL-SPM, Standard Practices Manual).
3.4.3.
Install a new stud in reworked hole (BHT-ALL-SPM, Standard Practices Manual).
3.4.4.
If the stud below the input quill bore was replaced, fill the top of the stud hole flush with the input quill bore with
adhesive (C-363). Do not allow the adhesive to obstruct the bore for the input quill.
3.4.5.
Fill all counterdrilled holes with sealant (C-308) flush with top of case.
4.
If any cracks are present in the aluminum boss at the three bearing liner taper pins, shown in Area M (Figure 1, Detail
B), rework the case as follows:
4.1.
File out the crack(s) with a rotary file. The minimum fillet radius after rework is 0.125 inch (3.18 mm). The maximum
allowable depth of cleanup is 0.060 inch (1.52 mm), measured from the original cast surface shown in Area M.
4.2.
Inspect the reworked cases by fluorescent penetrant method (BHT-ALL-SPM, Standard Practices Manual). If all
indications of crack(s) cannot be polished out within the limits noted in Step 4.1., the case is non-airworthy and
nonrepairable.
4.3.
Treat the rework area for corrosion protection as outlined in Step 3. (BHT-ALL-SPM, Standard Practices Manual).
5.
Rework Area I to remove corrosion damage as follows:
5.1.
Polish out corrosion damage, at four locations between the ends of the shim plates. Radius rework the area within 1/2
(0.50)-inch (12.7-mm) radius. If the corrosion extends into the shim area or seal area and/ or exceeds the depth limit
noted in Figure 1, the case is non-airworthy and nonrepairable.
5.2.
Polish the rework area with 400 grit abrasive cloth or paper (C-406).
6.
Touch up all areas on the case where chemical film has been removed with chemical film material (C-100) for
aluminum brush-on treatment (BHT-ALL-SPM, Standard Practices Manual).
7.
Touch up cadmium plate on the shim plates (7, 16, 21, and 25, Figure 2) (BHT-ALL-SPM, Standard Practices Manual).
Applicable to: ALL
412-A-63-10-00-09A-685A-B
ECCN EAR99
31 MAY 2023 Page 00145-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00130-A-001-01
Figure 1. Main Bevel Gear Case - Damage Limits (Sheet 1 of 3)
412-A-63-10-00-09A-685A-B
Applicable to: ALL
Page 00145-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00131-A-001-01
Figure 1. Main Bevel Gear Case - Damage Limits (Sheet 2 of 3)
Applicable to: ALL
412-A-63-10-00-09A-685A-B
ECCN EAR99
31 MAY 2023 Page 00145-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00132-A-001-01
Figure 1. Main Bevel Gear Case - Damage Limits (Sheet 3 of 3)
412-A-63-10-00-09A-685A-B
Applicable to: ALL
Page 00145-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00129-A-001-01
Figure 2. Transmission Main Case (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-09A-685A-B
ECCN EAR99
31 MAY 2023 Page 00145-5
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-09A-685A-B
Applicable to: ALL
Page 00145-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Transmission Main Bevel Gear Case (212-040-053-009) - Assembly
Procedure
1.
Inspect the shim plates (7, 16, 21, and 25, Figure 1) to ensure cadmium plate is intact prior to installation.
2.
Inspect the shim plates (7, 16, 21, and 25) and the main case (24) in the area where the shim plate is to be installed
for an etched serial number. The same serial number must be on both parts. If the existing shim plates parts cannot
be identified by serial number, determine the required dimension of the shims as outlined in Step 2.1. through
Step 2.3.. If a new shim plate is required, comply with Step 2.4. and Step 2.5..
2.1.
Inspect the main case (24) for a reference dimension, which should be metal stamped or vibro-etched on the case
adjacent to the mounting surface. Record this dimension and where it is located on the case.
2.2.
If a shim plate of the correct part number is available, but without a serial number, measure the thickness and record.
2.3.
Add the shim plate thickness to the reference dimension found on the main case. The resulting value must fall within
the required dimension provided in Table 1.
2.4.
If the required shim plate is missing, subtract the value recorded in Step 2.1. from the required dimension value listed
in Table 1. The resulting value is the required thickness of the shim plate.
2.5.
Procure shim plate(s) of the correct dimension, as determined in the previous steps, from Bell, Atten: CPR Dept.
Include all the pertinent information relative to the shim location and the referenced dimensions used in calculating
the shim thickness.
3.
Visually inspect the main case (24) to ensure that the washer seats (2, 6, 18, and 23), inserts (8, 14, and 27),
and clinch nuts (12) are properly installed.
4.
Install the shim plate set (1) on the top flange of the main case (24) and secure with screws (29).
5.
Put the shim plate (7) on the main case and install three screws (5).
6.
Put the shim plate (16) on the main case and install three screws (15).
7.
Put the shim plate (21) on the main case and install three screws (22).
8.
Put the shim plate (25) on the main case and install three screws (26).
9.
Put the input gear shaft bearing (20) in the case and install retaining ring (19).
10.
Put the input pinion bearing (3) in the case and install retaining ring (4).
Table 1. Main Bevel Gear Case - Required Dimension
LOCATION
SHIM PLATE
REQUIRED DIMENSION
MINIMUM INCHES (MM)
MAXIMUM INCHES (MM)
Main Case, Top
212-040-053-101
212-040-053-017
6.1240 (155.5496)
6.1250 (155.5750)
Main Case, Top
212-040-053-009
212-040-053-017
6.1340 (155.8036)
6.1350 (155.8290)
Main Case, Rear Port
212-040-053-015
8.6420 (219.5068)
8.6425 (219.5195)
Main Case, Front Port
212-040-053-013
7.4715 (189.7761)
7.4720 (189.7888)
Main Case, Left Port
212-040-053-013
7.4715 (189.7761)
7.4720 (189.7888)
Main Case, Right Port
212-040-053-013
7.4715 (189.7761)
7.4720 (189.7888)
Applicable to: ALL
412-A-63-10-00-09A-710A-B
ECCN EAR99
31 MAY 2023 Page 00146-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00129-A-001-01
Figure 1. Transmission Main Case (Sheet 1 of 1)
412-A-63-10-00-09A-710A-B
Applicable to: ALL
Page 00146-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Transmission Main Support Case (212-040-054-013, -101, -105, -109 and -117) - Disassembly
Procedure
1.
Remove the cotter pins (4, Figure 1 or Figure 2 or Figure 3), nuts (3), steel washers (2), and the lift link fitting (5) from
the main support case (7). Discard the cotter pins (4).
2.
Remove the screws (8) and the washers (9 and 10) from the top and bottom of the main support case (7) lateral
mounts.
Applicable to: ALL
412-A-63-10-00-10A-530A-B
ECCN EAR99
28 OCT 2024 Page 00147-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00107-A-001-01
Figure 1. Main Support Case (212-040-054-013, -101, -105) and Lift Link Fitting — Damage Limits (Sheet 1 of 5)
412-A-63-10-00-10A-530A-B
Applicable to: ALL
Page 00147-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00108-A-001-01
Figure 1. Main Support Case (212-040-054-013, -101, -105) and Lift Link Fitting — Damage Limits (Sheet 2 of 5)
Applicable to: ALL
412-A-63-10-00-10A-530A-B
ECCN EAR99
28 OCT 2024 Page 00147-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00109-A-003-01
Figure 1. Main Support Case (212-040-054-013, -101, -105) and Lift Link Fitting — Damage Limits (Sheet 3 of 5)
412-A-63-10-00-10A-530A-B
Applicable to: ALL
Page 00147-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00110-A-001-01
Figure 1. Main Support Case (212-040-054-013, -101, -105) and Lift Link Fitting — Damage Limits (Sheet 4 of 5)
Applicable to: ALL
412-A-63-10-00-10A-530A-B
ECCN EAR99
28 OCT 2024 Page 00147-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00111-A-001-01
Figure 1. Main Support Case (212-040-054-013, -101, -105) and Lift Link Fitting — Damage Limits (Sheet 5 of 5)
412-A-63-10-00-10A-530A-B
Applicable to: ALL
Page 00147-6 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00133-A-001-01
Figure 2. Main Support Case (212-040-054-109) and Lift Link Fitting - Damage Limits (Sheet 1 of 5)
Applicable to: ALL
412-A-63-10-00-10A-530A-B
ECCN EAR99
28 OCT 2024 Page 00147-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00134-A-001-01
Figure 2. Main Support Case (212-040-054-109) and Lift Link Fitting - Damage Limits (Sheet 2 of 5)
412-A-63-10-00-10A-530A-B
Applicable to: ALL
Page 00147-8 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00135-A-002-01
Figure 2. Main Support Case (212-040-054-109) and Lift Link Fitting - Damage Limits (Sheet 3 of 5)
Applicable to: ALL
412-A-63-10-00-10A-530A-B
ECCN EAR99
28 OCT 2024 Page 00147-9
BHT-412-CRO
ICN-412-A-631000-B-97499-00136-A-001-01
Figure 2. Main Support Case (212-040-054-109) and Lift Link Fitting - Damage Limits (Sheet 4 of 5)
412-A-63-10-00-10A-530A-B
Applicable to: ALL
Page 00147-10 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00137-A-001-01
Figure 2. Main Support Case (212-040-054-109) and Lift Link Fitting - Damage Limits (Sheet 5 of 5)
Applicable to: ALL
412-A-63-10-00-10A-530A-B
ECCN EAR99
28 OCT 2024 Page 00147-11
BHT-412-CRO
ICN-412-A-631000-B-97499-00138-A-002-01
Figure 3. Main Support Case (212-040-054-117) and Lift Link Fitting - Damage Limits (Sheet 1 of 5)
412-A-63-10-00-10A-530A-B
Applicable to: ALL
Page 00147-12 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00139-A-001-01
Figure 3. Main Support Case (212-040-054-117) and Lift Link Fitting - Damage Limits (Sheet 2 of 5)
Applicable to: ALL
412-A-63-10-00-10A-530A-B
ECCN EAR99
28 OCT 2024 Page 00147-13
BHT-412-CRO
ICN-412-A-631000-B-97499-00140-A-002-01
Figure 3. Main Support Case (212-040-054-117) and Lift Link Fitting - Damage Limits (Sheet 3 of 5)
412-A-63-10-00-10A-530A-B
Applicable to: ALL
Page 00147-14 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00141-A-001-01
Figure 3. Main Support Case (212-040-054-117) and Lift Link Fitting - Damage Limits (Sheet 4 of 5)
Applicable to: ALL
412-A-63-10-00-10A-530A-B
ECCN EAR99
28 OCT 2024 Page 00147-15
BHT-412-CRO
ICN-412-A-631000-B-97499-00142-A-001-01
Figure 3. Main Support Case (212-040-054-117) and Lift Link Fitting - Damage Limits (Sheet 5 of 5)
412-A-63-10-00-10A-530A-B
Applicable to: ALL
Page 00147-16 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Transmission Main Support Case (212-040-054-013, -101, -105, -109 and -117) - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Chromic acid treatment
Drycleaning solvent
Paint remover
C-103
C-304
C-436
AR
AR
AR
Remarks
Procedure
1.
Before cleaning, examine all the studs in the main support case (7) for corrosion. Refer to Figure 1 or Figure 2
or Figure 3 for the inspection procedure.
2.
Clean the main support case (7) with drycleaning solvent (C-304) and dry with filtered compressed air.
3.
Remove the sealant with a plastic scraper.
4.
Remove the paint with paint remover (C-436). Flush with water and dry with filtered compressed air.
5.
If the main support case (7) is corroded, remove the corrosion with chromic acid treatment (C-103) pickle process for
cleaning magnesium parts (BHT-ALL-SPM, Standard Practices Manual).
Applicable to: ALL
412-A-63-10-00-10A-258A-B
ECCN EAR99
28 OCT 2024 Page 00148-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00107-A-001-01
Figure 1. Main Support Case (212-040-054-013, -101, -105) and Lift Link Fitting — Damage Limits (Sheet 1 of 5)
412-A-63-10-00-10A-258A-B
Applicable to: ALL
Page 00148-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00108-A-001-01
Figure 1. Main Support Case (212-040-054-013, -101, -105) and Lift Link Fitting — Damage Limits (Sheet 2 of 5)
Applicable to: ALL
412-A-63-10-00-10A-258A-B
ECCN EAR99
28 OCT 2024 Page 00148-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00109-A-003-01
Figure 1. Main Support Case (212-040-054-013, -101, -105) and Lift Link Fitting — Damage Limits (Sheet 3 of 5)
412-A-63-10-00-10A-258A-B
Applicable to: ALL
Page 00148-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00110-A-001-01
Figure 1. Main Support Case (212-040-054-013, -101, -105) and Lift Link Fitting — Damage Limits (Sheet 4 of 5)
Applicable to: ALL
412-A-63-10-00-10A-258A-B
ECCN EAR99
28 OCT 2024 Page 00148-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00111-A-001-01
Figure 1. Main Support Case (212-040-054-013, -101, -105) and Lift Link Fitting — Damage Limits (Sheet 5 of 5)
412-A-63-10-00-10A-258A-B
Applicable to: ALL
Page 00148-6 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00133-A-001-01
Figure 2. Main Support Case (212-040-054-109) and Lift Link Fitting - Damage Limits (Sheet 1 of 5)
Applicable to: ALL
412-A-63-10-00-10A-258A-B
ECCN EAR99
28 OCT 2024 Page 00148-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00134-A-001-01
Figure 2. Main Support Case (212-040-054-109) and Lift Link Fitting - Damage Limits (Sheet 2 of 5)
412-A-63-10-00-10A-258A-B
Applicable to: ALL
Page 00148-8 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00135-A-002-01
Figure 2. Main Support Case (212-040-054-109) and Lift Link Fitting - Damage Limits (Sheet 3 of 5)
Applicable to: ALL
412-A-63-10-00-10A-258A-B
ECCN EAR99
28 OCT 2024 Page 00148-9
BHT-412-CRO
ICN-412-A-631000-B-97499-00136-A-001-01
Figure 2. Main Support Case (212-040-054-109) and Lift Link Fitting - Damage Limits (Sheet 4 of 5)
412-A-63-10-00-10A-258A-B
Applicable to: ALL
Page 00148-10 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00137-A-001-01
Figure 2. Main Support Case (212-040-054-109) and Lift Link Fitting - Damage Limits (Sheet 5 of 5)
Applicable to: ALL
412-A-63-10-00-10A-258A-B
ECCN EAR99
28 OCT 2024 Page 00148-11
BHT-412-CRO
ICN-412-A-631000-B-97499-00138-A-002-01
Figure 3. Main Support Case (212-040-054-117) and Lift Link Fitting - Damage Limits (Sheet 1 of 5)
412-A-63-10-00-10A-258A-B
Applicable to: ALL
Page 00148-12 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00139-A-001-01
Figure 3. Main Support Case (212-040-054-117) and Lift Link Fitting - Damage Limits (Sheet 2 of 5)
Applicable to: ALL
412-A-63-10-00-10A-258A-B
ECCN EAR99
28 OCT 2024 Page 00148-13
BHT-412-CRO
ICN-412-A-631000-B-97499-00140-A-002-01
Figure 3. Main Support Case (212-040-054-117) and Lift Link Fitting - Damage Limits (Sheet 3 of 5)
412-A-63-10-00-10A-258A-B
Applicable to: ALL
Page 00148-14 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00141-A-001-01
Figure 3. Main Support Case (212-040-054-117) and Lift Link Fitting - Damage Limits (Sheet 4 of 5)
Applicable to: ALL
412-A-63-10-00-10A-258A-B
ECCN EAR99
28 OCT 2024 Page 00148-15
BHT-412-CRO
ICN-412-A-631000-B-97499-00142-A-001-01
Figure 3. Main Support Case (212-040-054-117) and Lift Link Fitting - Damage Limits (Sheet 5 of 5)
412-A-63-10-00-10A-258A-B
Applicable to: ALL
Page 00148-16 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Transmission Main Support Case (212-040-054-013, -101, -105, -109 and -117) - Inspection
Procedure
1.
Examine the main support case (7, Figure 1 or Figure 2 or Figure 3) with fluorescent penetrant method
(BHT-ALL-SPM, Standard Practices Manual).
2.
Examine the main support case (7) in accordance with Figure 1 or Figure 2 or Figure 3, as applicable.
3.
Examine the screws (8) for corrosion and thread damage. Replace the screw(s) (8) if you find corrosion or thread
damage.
4.
Examine the top and bottom washers (9 and 10) for corrosion and pitting. Replace the washer(s) (9 and 10) if the
corrosion or pitting is more than 10% of any surface or is deeper than .01 inches (.3 mm).
5.
Examine the installed case bushings (11) for corrosion and pitting. The corrosion or pitting inside the bushing bore
must not be more than 10% of the surface or .005 inches (.1 mm) depth. The corrosion or pitting on bushing flange
or chamfer must not be more than 10% of the surface or .01 inches (.3 mm) depth. If the limits are more than the
specified limits, contact Product Support Engineering (PSE) for possible repairs.
6.
Examine the main support case (7) lateral mounts, top and bottom machined surfaces under or adjacent to the
washers (9 and 10) for pitting and the screw (8) holes for thread damage. Maximum depth of pitting must not
be more than .03 inches (.8 mm). Affected area must not be more than 0.75 square inch (483.87 mm2) total
for each pad surface or 50% of any .50 inches (12.7 mm) diameter. Damage to the threaded holes (8-32 NC-2B
x 0.62 depth) must not exceed 1 thread depth maximum. Replace the main support case (7) if the damages are
more than the specified limits.
Applicable to: ALL
412-A-63-10-00-10A-280A-B
ECCN EAR99
28 OCT 2024 Page 00149-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00107-A-001-01
Figure 1. Main Support Case (212-040-054-013, -101, -105) and Lift Link Fitting — Damage Limits (Sheet 1 of 5)
412-A-63-10-00-10A-280A-B
Applicable to: ALL
Page 00149-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00108-A-001-01
Figure 1. Main Support Case (212-040-054-013, -101, -105) and Lift Link Fitting — Damage Limits (Sheet 2 of 5)
Applicable to: ALL
412-A-63-10-00-10A-280A-B
ECCN EAR99
28 OCT 2024 Page 00149-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00109-A-003-01
Figure 1. Main Support Case (212-040-054-013, -101, -105) and Lift Link Fitting — Damage Limits (Sheet 3 of 5)
412-A-63-10-00-10A-280A-B
Applicable to: ALL
Page 00149-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00110-A-001-01
Figure 1. Main Support Case (212-040-054-013, -101, -105) and Lift Link Fitting — Damage Limits (Sheet 4 of 5)
Applicable to: ALL
412-A-63-10-00-10A-280A-B
ECCN EAR99
28 OCT 2024 Page 00149-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00111-A-001-01
Figure 1. Main Support Case (212-040-054-013, -101, -105) and Lift Link Fitting — Damage Limits (Sheet 5 of 5)
412-A-63-10-00-10A-280A-B
Applicable to: ALL
Page 00149-6 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00133-A-001-01
Figure 2. Main Support Case (212-040-054-109) and Lift Link Fitting -Damage Limits (Sheet 1 of 5)
Applicable to: ALL
412-A-63-10-00-10A-280A-B
ECCN EAR99
28 OCT 2024 Page 00149-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00134-A-001-01
Figure 2. Main Support Case (212-040-054-109) and Lift Link Fitting -Damage Limits (Sheet 2 of 5)
412-A-63-10-00-10A-280A-B
Applicable to: ALL
Page 00149-8 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00135-A-002-01
Figure 2. Main Support Case (212-040-054-109) and Lift Link Fitting -Damage Limits (Sheet 3 of 5)
Applicable to: ALL
412-A-63-10-00-10A-280A-B
ECCN EAR99
28 OCT 2024 Page 00149-9
BHT-412-CRO
ICN-412-A-631000-B-97499-00136-A-001-01
Figure 2. Main Support Case (212-040-054-109) and Lift Link Fitting -Damage Limits (Sheet 4 of 5)
412-A-63-10-00-10A-280A-B
Applicable to: ALL
Page 00149-10 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00137-A-001-01
Figure 2. Main Support Case (212-040-054-109) and Lift Link Fitting -Damage Limits (Sheet 5 of 5)
Applicable to: ALL
412-A-63-10-00-10A-280A-B
ECCN EAR99
28 OCT 2024 Page 00149-11
BHT-412-CRO
ICN-412-A-631000-B-97499-00138-A-002-01
Figure 3. Main Support Case (212-040-054-117) and Lift Link Fitting -Damage Limits (Sheet 1 of 5)
412-A-63-10-00-10A-280A-B
Applicable to: ALL
Page 00149-12 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00139-A-001-01
Figure 3. Main Support Case (212-040-054-117) and Lift Link Fitting -Damage Limits (Sheet 2 of 5)
Applicable to: ALL
412-A-63-10-00-10A-280A-B
ECCN EAR99
28 OCT 2024 Page 00149-13
BHT-412-CRO
ICN-412-A-631000-B-97499-00140-A-002-01
Figure 3. Main Support Case (212-040-054-117) and Lift Link Fitting -Damage Limits (Sheet 3 of 5)
412-A-63-10-00-10A-280A-B
Applicable to: ALL
Page 00149-14 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00141-A-001-01
Figure 3. Main Support Case (212-040-054-117) and Lift Link Fitting -Damage Limits (Sheet 4 of 5)
Applicable to: ALL
412-A-63-10-00-10A-280A-B
ECCN EAR99
28 OCT 2024 Page 00149-15
BHT-412-CRO
ICN-412-A-631000-B-97499-00142-A-001-01
Figure 3. Main Support Case (212-040-054-117) and Lift Link Fitting -Damage Limits (Sheet 5 of 5)
412-A-63-10-00-10A-280A-B
Applicable to: ALL
Page 00149-16 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Transmission Main Support Case (212-040-054-013, -101, -105, -109 and -117) - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Chromic acid treatment
Epoxy polyamide primer
Sealant
Abrasive cloth or paper
Cadmium plating solution
C-103
C-204
C-308
C-406
C-108
AR
AR
AR
AR
AR
Remarks
Procedure
NOTE
If you return the part to Bell, refer to General Information Letter (IL) GEN-04-98 for applicable shipping
information and to get a Return Material Authorization (RMA) number.
1.
Replace a sheared dowel pin (1), if the damage is less than the limits shown in Figure 1 or Figure 2 or Figure 3, as
applicable. If the limits are more than the specified limits, send the part to Bell for analysis and possible repair.
2.
If the main support case (7) is corroded in the area adjacent to the studs, or if the studs are corroded, repair as follows:
2.1.
Measure and record the height of the stud.
2.2.
Remove the stud from the corrosion damaged area.
2.3.
If the corrosion has affected more than one complete thread, the main support case (7) is non-airworthy and
non-repairable.
2.4.
If the corrosion has affected less than one complete thread, repair the main support case (7) as follows:
2.4.1.
In Area F, counterdrill the stud holes 0.327 to 0.334 inches (8.3 to 8.5 mm) in diameter and a maximum depth of
0.125 inches (3.2 mm). Break all sharp edges, except in the threaded area.
2.4.2.
In Area G, counter-drill stud holes 0.452 to 0.459 inches (11.5 to 11.7 mm) in diameter and a maximum depth of
0.156 inches (4.0 mm). Break all sharp edges, except in the threaded area.
2.4.3.
After drilling, apply the surfaces with chromic acid treatment (C-103) (BHT-ALL-SPM, Standard Practices Manual).
2.4.4.
Install a new stud in the repaired hole (BHT-ALL-SPM, Standard Practices Manual).
2.4.5.
Fill all counterdrilled holes flush with the top of the main support case (7) with sealant (C-308).
3.
Polish out mechanical and corrosion damage on the main support case (7) and the lift link fitting (5) that is within the
limits noted in Figure 1 or Figure 2 or Figure 3. Polish the repaired area with 400 grit abrasive cloth or paper (C-406).
4.
Apply all areas on the main support case (7) where chemical film has been removed with chromic acid treatment
(C-103) (BHT-ALL-SPM, Standard Practices Manual).
5.
Examine all areas on the main support case (7) that were repaired in Step 2.1. through Step 2.4. with fluorescent
penetrant method. Refer to BHT-ALL-SPM, Standard Practices Manual for procedure.
6.
Repair the washers (9 and 10), if the corrosion or pitting is below the specified limits. Remove the corrosion or pitting
with a polishing pad or a fine sand paper. Touch up repaired areas with cadmium plating solution (C-108) per
BHT-ALL-SPM, Standard Practices Manual.
7.
Repair the bushing(s) (11), if the corrosion or pitting is below the specified limits. Remove the corrosion or pitting
with a polishing pad or a fine sand paper. Touch up repaired areas with cadmium plating solution (C-108) per
BHT-ALL-SPM, Standard Practices Manual. If the damages are more than the specified limits, contact Product
Support Engineering (PSE) for possible repair.
8.
Repair the main support case (7) lateral mounts if pitting or screw (8) holes damages are below the specified limits.
Blend out all the pitting in the machined corner radius (bottom flange surfaces (4 places)). Do not blend out the pitting
on the flange faces unless it is within 0.03 inches (.8 mm) of the flange edge. Remove all the loose corrosion debris
Applicable to: ALL
412-A-63-10-00-10A-685A-B
ECCN EAR99
28 OCT 2024 Page 00150-1
BHT-412-CRO
and apply the magnesium alloy surface treatment per BHT-ALL-SPM, Standard Practices Manual. After treatment, fill
in all the affected areas with epoxy polyamide primer (C-204).
412-A-63-10-00-10A-685A-B
Applicable to: ALL
Page 00150-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00107-A-001-01
Figure 1. Main Support Case (212-040-054-013, -101, -105) and Lift Link Fitting — Damage Limits (Sheet 1 of 5)
Applicable to: ALL
412-A-63-10-00-10A-685A-B
ECCN EAR99
28 OCT 2024 Page 00150-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00108-A-001-01
Figure 1. Main Support Case (212-040-054-013, -101, -105) and Lift Link Fitting — Damage Limits (Sheet 2 of 5)
412-A-63-10-00-10A-685A-B
Applicable to: ALL
Page 00150-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00109-A-003-01
Figure 1. Main Support Case (212-040-054-013, -101, -105) and Lift Link Fitting — Damage Limits (Sheet 3 of 5)
Applicable to: ALL
412-A-63-10-00-10A-685A-B
ECCN EAR99
28 OCT 2024 Page 00150-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00110-A-001-01
Figure 1. Main Support Case (212-040-054-013, -101, -105) and Lift Link Fitting — Damage Limits (Sheet 4 of 5)
412-A-63-10-00-10A-685A-B
Applicable to: ALL
Page 00150-6 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00111-A-001-01
Figure 1. Main Support Case (212-040-054-013, -101, -105) and Lift Link Fitting — Damage Limits (Sheet 5 of 5)
Applicable to: ALL
412-A-63-10-00-10A-685A-B
ECCN EAR99
28 OCT 2024 Page 00150-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00133-A-001-01
Figure 2. Main Support Case (212-040-054-109) and Lift Link Fitting -Damage Limits (Sheet 1 of 5)
412-A-63-10-00-10A-685A-B
Applicable to: ALL
Page 00150-8 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00134-A-001-01
Figure 2. Main Support Case (212-040-054-109) and Lift Link Fitting -Damage Limits (Sheet 2 of 5)
Applicable to: ALL
412-A-63-10-00-10A-685A-B
ECCN EAR99
28 OCT 2024 Page 00150-9
BHT-412-CRO
ICN-412-A-631000-B-97499-00135-A-002-01
Figure 2. Main Support Case (212-040-054-109) and Lift Link Fitting -Damage Limits (Sheet 3 of 5)
412-A-63-10-00-10A-685A-B
Applicable to: ALL
Page 00150-10 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00136-A-001-01
Figure 2. Main Support Case (212-040-054-109) and Lift Link Fitting -Damage Limits (Sheet 4 of 5)
Applicable to: ALL
412-A-63-10-00-10A-685A-B
ECCN EAR99
28 OCT 2024 Page 00150-11
BHT-412-CRO
ICN-412-A-631000-B-97499-00137-A-001-01
Figure 2. Main Support Case (212-040-054-109) and Lift Link Fitting -Damage Limits (Sheet 5 of 5)
412-A-63-10-00-10A-685A-B
Applicable to: ALL
Page 00150-12 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00138-A-002-01
Figure 3. Main Support Case (212-040-054-117) and Lift Link Fitting -Damage Limits (Sheet 1 of 5)
Applicable to: ALL
412-A-63-10-00-10A-685A-B
ECCN EAR99
28 OCT 2024 Page 00150-13
BHT-412-CRO
ICN-412-A-631000-B-97499-00139-A-001-01
Figure 3. Main Support Case (212-040-054-117) and Lift Link Fitting -Damage Limits (Sheet 2 of 5)
412-A-63-10-00-10A-685A-B
Applicable to: ALL
Page 00150-14 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00140-A-002-01
Figure 3. Main Support Case (212-040-054-117) and Lift Link Fitting -Damage Limits (Sheet 3 of 5)
Applicable to: ALL
412-A-63-10-00-10A-685A-B
ECCN EAR99
28 OCT 2024 Page 00150-15
BHT-412-CRO
ICN-412-A-631000-B-97499-00141-A-001-01
Figure 3. Main Support Case (212-040-054-117) and Lift Link Fitting -Damage Limits (Sheet 4 of 5)
412-A-63-10-00-10A-685A-B
Applicable to: ALL
Page 00150-16 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00142-A-001-01
Figure 3. Main Support Case (212-040-054-117) and Lift Link Fitting -Damage Limits (Sheet 5 of 5)
Applicable to: ALL
412-A-63-10-00-10A-685A-B
ECCN EAR99
28 OCT 2024 Page 00150-17
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-10A-685A-B
Applicable to: ALL
Page 00150-18 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Transmission Main Support Case (212-040-054-013, -101, -105, -109 and -117) - Assembly
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Zinc chromate primer
Sealant
C-201
C-308
AR
AR
Remarks
Procedure
1.
Install the lift link fitting (5, Figure 1 or Figure 2 or Figure 3) on the main support case (7) with the steel washers
(2) and the nuts (3).
2.
For studs that are size 7/16 0.4375 inches (11.1 mm) torque the nuts (3) 37 to 42 foot-pounds (50.2 to 56.9 Nm).
Safety the nuts (3) with new cotter pins (4).
3.
For studs that are size 1/2 0.50 inches (12.7 mm) torque the nuts (3) 40 to 58 foot-pounds (54.2 to 78.6 Nm).
Safety the nuts (3) with new cotter pins (4).
4.
Apply zinc chromate primer (C-201) and install the washers (9) and screws (8) on the top of the main support
lateral mounts (4 places).
5.
Apply zinc chromate primer (C-201) and install the washers (10) and screws (8) on the bottom of the main support
lateral mounts (4 places).
6.
Apply a bead sealant (C-308) sealant to outer diameter (OD) of washers (9 and 10) in the joint where it meets the
main support case (7) and to the area between bushing (11) flange and washer (9 or 10), where water entrapment
can occur. Make sure the sealant (C-308) does not extend above surface of washers (9 and 10) or interfere with
inner diameter (ID) of bushings.
Applicable to: ALL
412-A-63-10-00-10A-710A-B
ECCN EAR99
28 OCT 2024 Page 00151-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00107-A-001-01
Figure 1. Main Support Case (212-040-054-013, -101, -105) and Lift Link Fitting — Damage Limits (Sheet 1 of 5)
412-A-63-10-00-10A-710A-B
Applicable to: ALL
Page 00151-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00108-A-001-01
Figure 1. Main Support Case (212-040-054-013, -101, -105) and Lift Link Fitting — Damage Limits (Sheet 2 of 5)
Applicable to: ALL
412-A-63-10-00-10A-710A-B
ECCN EAR99
28 OCT 2024 Page 00151-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00109-A-003-01
Figure 1. Main Support Case (212-040-054-013, -101, -105) and Lift Link Fitting — Damage Limits (Sheet 3 of 5)
412-A-63-10-00-10A-710A-B
Applicable to: ALL
Page 00151-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00110-A-001-01
Figure 1. Main Support Case (212-040-054-013, -101, -105) and Lift Link Fitting — Damage Limits (Sheet 4 of 5)
Applicable to: ALL
412-A-63-10-00-10A-710A-B
ECCN EAR99
28 OCT 2024 Page 00151-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00111-A-001-01
Figure 1. Main Support Case (212-040-054-013, -101, -105) and Lift Link Fitting — Damage Limits (Sheet 5 of 5)
412-A-63-10-00-10A-710A-B
Applicable to: ALL
Page 00151-6 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00133-A-001-01
Figure 2. Main Support Case (212-040-054-109) and Lift Link Fitting - Damage Limits (Sheet 1 of 5)
Applicable to: ALL
412-A-63-10-00-10A-710A-B
ECCN EAR99
28 OCT 2024 Page 00151-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00134-A-001-01
Figure 2. Main Support Case (212-040-054-109) and Lift Link Fitting - Damage Limits (Sheet 2 of 5)
412-A-63-10-00-10A-710A-B
Applicable to: ALL
Page 00151-8 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00135-A-002-01
Figure 2. Main Support Case (212-040-054-109) and Lift Link Fitting - Damage Limits (Sheet 3 of 5)
Applicable to: ALL
412-A-63-10-00-10A-710A-B
ECCN EAR99
28 OCT 2024 Page 00151-9
BHT-412-CRO
ICN-412-A-631000-B-97499-00136-A-001-01
Figure 2. Main Support Case (212-040-054-109) and Lift Link Fitting - Damage Limits (Sheet 4 of 5)
412-A-63-10-00-10A-710A-B
Applicable to: ALL
Page 00151-10 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00137-A-001-01
Figure 2. Main Support Case (212-040-054-109) and Lift Link Fitting - Damage Limits (Sheet 5 of 5)
Applicable to: ALL
412-A-63-10-00-10A-710A-B
ECCN EAR99
28 OCT 2024 Page 00151-11
BHT-412-CRO
ICN-412-A-631000-B-97499-00138-A-002-01
Figure 3. Main Support Case (212-040-054-117) and Lift Link Fitting - Damage Limits (Sheet 1 of 5)
412-A-63-10-00-10A-710A-B
Applicable to: ALL
Page 00151-12 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00139-A-001-01
Figure 3. Main Support Case (212-040-054-117) and Lift Link Fitting - Damage Limits (Sheet 2 of 5)
Applicable to: ALL
412-A-63-10-00-10A-710A-B
ECCN EAR99
28 OCT 2024 Page 00151-13
BHT-412-CRO
ICN-412-A-631000-B-97499-00140-A-002-01
Figure 3. Main Support Case (212-040-054-117) and Lift Link Fitting - Damage Limits (Sheet 3 of 5)
412-A-63-10-00-10A-710A-B
Applicable to: ALL
Page 00151-14 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00141-A-001-01
Figure 3. Main Support Case (212-040-054-117) and Lift Link Fitting - Damage Limits (Sheet 4 of 5)
Applicable to: ALL
412-A-63-10-00-10A-710A-B
ECCN EAR99
28 OCT 2024 Page 00151-15
BHT-412-CRO
ICN-412-A-631000-B-97499-00142-A-001-01
Figure 3. Main Support Case (212-040-054-117) and Lift Link Fitting - Damage Limits (Sheet 5 of 5)
412-A-63-10-00-10A-710A-B
Applicable to: ALL
Page 00151-16 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Planetary Ring Gear, Upper Planetary, and Lower Planetary Assemblies - Description
This section contains instructions to overhaul the planetary ring gear, upper planetary, and lower planetary assemblies.
Applicable to: ALL
412-A-63-10-00-02A-028A-B
ECCN EAR99
31 MAY 2023 Page 00152-1
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-02A-028A-B
Applicable to: ALL
Page 00152-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Planetary Ring Gear (205-040-231-009) - Disassembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Backup Ring
204-240-009-001 or
204-040-009-1 PAT-2D
T101332
T101572
T101574
1
Guide Pin
Alignment Fixture
Shaft Guide
Remarks
1
1
1
Procedure
1.
If not previously accomplished, remove three jet housings from the planetary ring gear (412-A-63-10-00-06A-530A-B /
00127).
Applicable to: ALL
412-A-63-10-00-11A-530A-B
ECCN EAR99
31 MAY 2023 Page 00153-1
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-11A-530A-B
Applicable to: ALL
Page 00153-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Planetary Ring Gear (205-040-231-009) - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Drycleaning solvent
Paint remover
Clean cloth
C-304
C-436
C-516
AR
AR
AR
Remarks
Procedure
1.
Remove paint from the surface with paint remover (C-436).
2.
Clean the ring gear with drycleaning solvent (C-304) and a soft bristle brush.
3.
Dry the part with a clean cloth (C-516) or dry, filtered, compressed air.
4.
Remove the sealant with a plastic scraper.
Applicable to: ALL
412-A-63-10-00-11A-258A-B
ECCN EAR99
31 MAY 2023 Page 00154-1
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-11A-258A-B
Applicable to: ALL
Page 00154-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Planetary Ring Gear (205-040-231-009) - Inspection
Procedure
1.
Inspect the ring gear (Figure 1) by magnetic particle method. Demagnetize parts after the magnetic particle
inspection. Refer to Table 1 and the BHT-ALL-SPM, Standard Practices Manual for the inspection procedures.
2.
Inspect the ring gear teeth for wear patterns. Replace the gear if it exceeds wear and damage limits (Figure 1).
Table 1. Magnetic Particle Inspection
PART NUMBER
NOMENCLATURE
ITEM AND FIGURE
SET UP AND MAGNETIZATION CURRENT REQUIREMENTS
205-040-231-009
Ring Gear
Figure 1
SET UP:
Place part over a 2.0-inches (51-mm) diameter central conductor.
Current for primary diameters, magnetize at 3580 amps.
Optional current for secondary diameters, magnetize at 2000 amps.
Large I.D. of part: Magnetize at seven approximately equally spaced radial locations on central conductor.
Omit coil shot.
NOTES:
1. Magnetization currents provided are applicable to magnetic particle inspection apparatus using Direct Current (DC) . If an
Alternating Current (AC) apparatus is used, adjust the current as follows: AC= 0.667 x DC.
2. Ferrous parts requiring magnetic particle inspection that are not addressed in the attached material, are to be inspected in
accordance with the general procedures outlined in ASTM E1444 standard practices (BHT-ALL-SPM, Chapter 6, Standard
Practices Manual).
3. Part numbers listed apply to all successive dash numbers for that component unless otherwise specified.
Applicable to: ALL
412-A-63-10-00-11A-280A-B
ECCN EAR99
31 MAY 2023 Page 00155-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00143-A-001-01
Figure 1. Planetary Ring Gear - Damage and Wear Limits (Sheet 1 of 3)
412-A-63-10-00-11A-280A-B
Applicable to: ALL
Page 00155-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00144-A-001-01
Figure 1. Planetary Ring Gear - Damage and Wear Limits (Sheet 2 of 3)
Applicable to: ALL
412-A-63-10-00-11A-280A-B
ECCN EAR99
31 MAY 2023 Page 00155-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00145-A-001-01
Figure 1. Planetary Ring Gear - Damage and Wear Limits (Sheet 3 of 3)
412-A-63-10-00-11A-280A-B
Applicable to: ALL
Page 00155-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Planetary Ring Gear (205-040-231-009) - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
India stone
C-464
AR
Remarks
Procedure
1.
Polish out minor damage on the ring gear teeth that is within limits (412-A-63-10-00-11A-280A-B / 00155) with a
fine india stone (C-464).
Applicable to: ALL
412-A-63-10-00-11A-685A-B
ECCN EAR99
31 MAY 2023 Page 00156-1
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-11A-685A-B
Applicable to: ALL
Page 00156-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Planetary Ring Gear (205-040-231-009) - Assembly
Procedure
1.
Install the three jet housings on the ring gear (412-A-63-10-00-06A-710A-B / 00133).
Applicable to: ALL
412-A-63-10-00-11A-710A-B
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31 MAY 2023 Page 00157-1
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Intentionally blank page
412-A-63-10-00-11A-710A-B
Applicable to: ALL
Page 00157-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Upper Planetary Assembly (204-040-360-005, -103, -105 And 412-040-360-101) - Disassembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Guide Pin
Shaft Guide
T101332
T101574
1
1
Remarks
Procedure
1.
Cut and remove the lockwire.
2.
Remove the nut (3, Figure 1) with the socket wrench square adapter.
3.
Put the planetary on the backup ring (204-240-009-001 or 204-040-009-1 PAT-2D).
4.
Thread the shaft guide (T101574) into the pinion shaft (1).
USE CARE WHEN REMOVING PINION FROM SPIDER TO PREVENT DAMAGE.
5.
Press the pinion shaft (1) out of the spider assembly (2).
PLANETARY BEARING ROLLERS (6) FROM EACH PINION ARE A MATCHED SET AND MUST NOT
BE INTERMIXED.
6.
Put the guide pin (T101332) through the bearing inner race (5) where the pinion shaft (1) was removed.
7.
Tap pinion gear (8) out of the side opening of the spider assembly (2). Hold the thrust washers (4 and 9) in place to
prevent bearing rollers (6) from falling out of the bearing retainer (7).
8.
Separate the thrust washers (4 and 9), bearing rollers (6), bearing retainer (7), and bearing inner race (5) from the
pinion gear (8). Keep the bearing rollers together as a matched set.
9.
Remove the seven remaining pinion gears (8) in the same manner outlined in Step 2. through Step 9..
NOTE
The spider assembly (2) consists of a plate and web that are assembled prior to final machining at time
of manufacture.
10.
Do not disassemble the spider assembly (2).
Applicable to: ALL
412-A-63-10-00-12A-530A-B
ECCN EAR99
28 OCT 2024 Page 00158-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00018-A-001-01
Figure 1. Upper Planetary Assembly (Sheet 1 of 3)
412-A-63-10-00-12A-530A-B
Applicable to: ALL
Page 00158-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00019-A-001-01
Figure 1. Upper Planetary Assembly (Sheet 2 of 3)
Applicable to: ALL
412-A-63-10-00-12A-530A-B
ECCN EAR99
28 OCT 2024 Page 00158-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00020-A-002-01
Figure 1. Upper Planetary Assembly (Sheet 3 of 3)
412-A-63-10-00-12A-530A-B
Applicable to: ALL
Page 00158-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Upper Planetary Assembly (204-040-360-005, -103, -105 and 412-040-360-101) - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Corrosion preventive compound
Drycleaning solvent
Solvent
Clean cloth
C-105
C-304
C-334
C-516
AR
AR
AR
AR
Remarks
Procedure
1.
Clean all the parts with drycleaning solvent (C-304). Use a soft bristle brush to dislodge stubborn deposits. If desired,
all the parts other than bearings may be cleaned with solvent (C-334) by vapor degreasing.
DO NOT ALLOW BEARINGS TO SPIN WHILE DRYING.
2.
Dry the parts with a clean cloth (C-516) or dry filtered compressed air.
DO NOT HANDLE UNOILED BEARINGS WITH BARE HANDS.
NOTE
Parts treated per the following step may be left covered in indoor storage for approximately 150 hours
without being affected by corrosion.
3.
Immediately after cleaning parts with solvent, gently agitate parts in corrosion preventive compound (C-105) and
allow to drain dry.
Applicable to: ALL
412-A-63-10-00-12A-258A-B
ECCN EAR99
28 OCT 2024 Page 00159-1
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-12A-258A-B
Applicable to: ALL
Page 00159-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Upper Planetary Assembly (204-040-360-005, -103, -105 And 412-040-360-101) - Inspection
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
India stone
C-464
AR
Remarks
Procedure
NOTE
Limits charts are provided to show the required fit between mating parts. It is not intended that all
dimensions listed on limits charts be checked as a prescribed overhaul procedure; however, parts that
show evidence of wear or physical damage must be checked dimensionally.
1.
Inspect the parts shown in Figure 1. Inspect all threaded parts for damaged threads. If any parts show evidence
of wear or physical damage when inspected during subsequent steps, measure dimensions to determine whether
the part is within limits.
2.
Inspect the wear pattern in the teeth of all upper planetary pinions. Refer to Figure 2 for examples of acceptable
and unacceptable wear patterns.
3.
Inspect the teeth on pinion gears (8, Figure 3) and splines on spider assembly (2) for nicks and dents, chipped and/or
broken and worn teeth. Any anomalies felt with a 0.020-inch (0.51-mm) spherical radius probe are unacceptable.
Minor damage that can be polished out with a fine india stone (C-464) is permitted if polished out.
THE SPIDER ASSEMBLY (2) CONSISTS OF A PLATE AND WEB, WHICH ARE A MATCHED SET. DO
NOT SEPARATE DURING MAGNETIC INSPECTION.
4.
Inspect the following parts by magnetic particle inspection. Demagnetize parts after magnetic particle inspection.
Refer to Table 2 and the BHT-ALL-SPM, Standard Practices Manual for the procedure.
Figure 3INDEX NUMBER
NOMENCLATURE
1
Pinion Shaft
2
Spider Assembly
3
Nut
5
Bearing Inner Race
7
Bearing Retainer (214-040-110 and 412-040-133)
8
Pinion Gear
Table 2. Magnetic Particle Inspection
PART NUMBER
NOMENCLATURE
ITEM AND FIGURE
SET UP AND MAGNETIZATION CURRENT REQUIREMENTS
HP/EP UPPER PLANETARY ASSEMBLY (204-040-360-005, -103, -105 AND 412-040-360-101)
204-040-397-001
Spider Assembly
2, Figure 3
SET UP:
Place part over 2-inch diameter central conductor.
Current for primary diameters, magnetize at 6000 amps.
Optional current for secondary diameters, magnetize at 1680 amps.
Large I.D. of part, magnetize at six approximately equally spaced radial locations on central conductor.
Applicable to: ALL
412-A-63-10-00-12A-280A-B
ECCN EAR99
28 OCT 2024 Page 00160-1
BHT-412-CRO
Table 2. Magnetic Particle Inspection (continued)
SET UP: 5 TURN COIL SHOT:
Disc-shaped portion of part: place part in bottom of coil.
Magnetize to 3000 amps.
Rotate part 1/4 turn and repeat.
204-040-130-005
Pinion Shaft
1, Figure 3
SET UP:
Place part over a 0.7-inch diameter central conductor.
Current for primary diameters, magnetize at 1250 amps.
Optional current for secondary diameters, magnetize at 848 amps.
Omit coil shot.
204-040-131-001
Nut
3, Figure 3
SET UP:
Place part over a 0.5-inch diameter central conductor.
Current for primary diameters, magnetize at 1340 amps.
Optional current for secondary diameters, magnetize at 742 amps.
Omit coil shot.
204-040-132-001 or 412-340-132-101
Bearing Inner Race
5, Figure 3
SET UP:
Place part over a 1.0-inch diameter central conductor.
Current for primary diameters, magnetize at 2000 amps.
SET UP: 5 TURN COIL SHOT:
Place part in bottom of coil such that the long axis of the part is 90° to the direction of the current flow through the coil.
Magnetize at 3000 amps.
205-040-233-001 or 412-040-234-101
Pinion Gear
8, Figure 3
SET UP:
Place part over a 2-inch diameter central conductor.
Current for primary diameters, magnetize at 2170 amps.
Omit coil shot.
NOTES:
1. Magnetization currents provided are applicable to magnetic particle inspection apparatus using Direct Current (DC) . If an
Alternating Current (AC) apparatus is used, adjust the current as follows: AC= 0.667 x DC.
2. Ferrous parts requiring magnetic particle inspection that are not addressed in the attached material, are to be inspected in
accordance with the general procedures outlined in ASTM E1444 standard practices (BHT-ALL-SPM, Chapter 6, Standard
Practices Manual).
3. Part numbers listed apply to all successive dash numbers for that component unless otherwise specified.
5.
Inspect the bearing retainer (7) for chips, cracks, wear, or damage, as shown in Figure 4.
412-A-63-10-00-12A-280A-B
Applicable to: ALL
Page 00160-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
6.
Inspect the bearing retainers (7), all part numbers, for embedded bearing chips or other steel particles in the tang
on the retainers. Retainers with embedded chips and/or mechanical damage that can be detected visually are
not permitted.
7.
Inspect the spider assembly (2, Figure 3) for corrosion pitting. Pitting is permitted on the top surface in the area
shown in Figure 3, Section E-E, except for the area contacted by the flange of the pinion shafts (1), provided damage
is polished out and the maximum depth after polishing does not exceed 0.010 inch (0.25 mm) and no more than
20% of any 1.0 square inch (645.2 mm2) is affected.
8.
Inspect the bearing inner races (5) and bearing rollers (6) for spalling, scoring, pitting, brinelling, indentations, and
corrosion. Damage that can be detected visually and with a 0.020-inch (0.51-mm) spherical radius probe is not
permitted. Light scoring on the bearing inner races in the area contacted by the bearing retainers (7) is permitted.
Applicable to: ALL
412-A-63-10-00-12A-280A-B
ECCN EAR99
28 OCT 2024 Page 00160-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00146-A-002-01
Figure 1. Upper Planetary Assembly - Wear Limits (Sheet 1 of 1)
412-A-63-10-00-12A-280A-B
Applicable to: ALL
Page 00160-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00147-A-001-01
Figure 2. Upper Planetary Pinion - Wear Patterns (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-12A-280A-B
ECCN EAR99
28 OCT 2024 Page 00160-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00018-A-001-01
Figure 3. Upper Planetary Assembly (Sheet 1 of 3)
412-A-63-10-00-12A-280A-B
Applicable to: ALL
Page 00160-6 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00019-A-001-01
Figure 3. Upper Planetary Assembly (Sheet 2 of 3)
Applicable to: ALL
412-A-63-10-00-12A-280A-B
ECCN EAR99
28 OCT 2024 Page 00160-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00020-A-002-01
Figure 3. Upper Planetary Assembly (Sheet 3 of 3)
412-A-63-10-00-12A-280A-B
Applicable to: ALL
Page 00160-8 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00148-A-002-01
Figure 4. Bearing Retainer - Damage Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-12A-280A-B
ECCN EAR99
28 OCT 2024 Page 00160-9
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-12A-280A-B
Applicable to: ALL
Page 00160-10 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Upper Planetary Assembly (204-040-360-005, -103, -105 And 412-040-360-101) - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Corrosion preventive compound
Drycleaning solvent
Cleaner
Abrasive cloth or paper
India stone
Clean cloth
C-105
C-304
C-344
C-406
C-464
C-516
AR
AR
AR
AR
AR
AR
Remarks
Procedure
1.
Polish out minor damage in the tops or ends of the teeth of the pinion gears (8, Figure 1) and the splines of the spider
assembly (2) with a fine india stone (C-464). Polishing is not permitted on the face of the teeth.
2.
Polish out corrosion pitting damage on the spider assembly (2) that is within limits (412-A-63-10-00-12A-280A-B /
00160) with fine grit abrasive cloth or paper (C-406).
3.
Remove the superficial corrosion from the spider assembly (2) that was not cleaned in the Step 2. as follows:
3.1.
If the spider assembly (2) is not free of oil, grease, and other similar contaminates, clean the spider with drycleaning
solvent (C-304).
3.2.
Mix 1 part cleaner (C-344) with 3 parts water.
3.3.
Apply cleaner prepared in Step 3.2. to the corroded areas of the spider. Do not apply to non-corroded areas. Apply
the cleaner with a brush or swab. Avoid getting cleaner in the joints between the spider halves, in the pinion shaft
holes, or in threaded holes. Leave the cleaner in contact with metal for 1 to 3 minutes.
3.4.
Rinse the cleaner off the spider thoroughly with clean water.
3.5.
Repeat Step 3.3. and Step 3.4., if necessary, to remove corrosion.
3.6.
Dry the planetary spider in an oven at 150°F (66°C) maximum. If an oven is not available, use a clean cloth (C-516)
or filtered compressed air.
4.
Immediately after cleaning the spider, immerse the spider in corrosion preventive compound (C-105). Agitate the
spider to ensure complete coverage. Place the spider on a rack and allow to drip dry. Apply a coat of approved
lubricating oil used in the transmission.
Applicable to: ALL
412-A-63-10-00-12A-685A-B
ECCN EAR99
28 OCT 2024 Page 00161-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00018-A-001-01
Figure 1. Upper Planetary Assembly (Sheet 1 of 3)
412-A-63-10-00-12A-685A-B
Applicable to: ALL
Page 00161-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00019-A-001-01
Figure 1. Upper Planetary Assembly (Sheet 2 of 3)
Applicable to: ALL
412-A-63-10-00-12A-685A-B
ECCN EAR99
28 OCT 2024 Page 00161-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00020-A-002-01
Figure 1. Upper Planetary Assembly (Sheet 3 of 3)
412-A-63-10-00-12A-685A-B
Applicable to: ALL
Page 00161-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Upper Planetary Assembly (204-040-360-005, -103, -105 And 412-040-360-101) - Assembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Guide Pin
Shaft Guide
T101332
T101574
1
1
Remarks
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Lockwire
C-405
AR
Remarks
Procedure
MAKE SURE THAT BEARING ROLLERS (6) ARE A MATCHED SET. ALL THE ROLLERS IN A SET
MUST BE FROM SAME MANUFACTURER. CHECK MANUFACTURER'S IDENTIFICATION MARK ON
END OF EACH ROLLER. ALSO, INDIVIDUAL ROLLERS ARE NOT INTERCHANGEABLE. IF ONE OR
MORE ROLLERS OF A SET FAIL TO PASS INSPECTION, THE ENTIRE SET MUST BE REPLACED.
ROLLER SETS WITH DIFFERENT DASH NUMBERS MAY BE USED IN THE SAME PLANETARY
ASSEMBLY, BUT ALL THE ROLLERS IN A SET FOR ONE PLANETARY PINION MUST BE OF SAME
DASH NUMBER.
1.
Put the spider assembly (2, Figure 1) on the backup ring (204-040-009 PAT-2D).
2.
Install the shaft guide (T101574) in the pinion shaft (1).
NOTE
Chamfer of thrust washers (4 and 9) is to be installed away from the bearing rollers (6).
3.
Assemble the pinion gear (8), bearing retainer (7), bearing inner race (5), bearing rollers (6), and thrust washers (4
and 9) on the guide pin (T101332). Hold the parts together and put in the spider assembly (2).
4.
Align the pinion with the spider and press the pinion shaft (1) into position through the pinion gear (8). The guide pin
(T101332) will be pressed out the lower side of the spider. Make sure that the pinion shaft is seated. Remove the
shaft guide (T101574) from the pinion shaft.
5.
Install the nut (3), but do not torque at this time.
6.
Install the remaining seven pinion gears (8) in the same manner outlined in Step 2. through Step 5..
7.
Torque the nut (3) on all the pinions 60 to 80 foot-pounds (81 to 108 Nm).
8.
Rotate each pinion gear (8) manually and check for binding in the spider. If the pinions do not turn freely, check the
bearing retainer (7) for burrs. Check for foreign material in the bearing. No binding is permitted. If necessary,
disassemble the planetary to determine the cause of binding.
9.
Measure the distance between the ends of each bearing roller (6) and the thrust washers (4 and 9) with a feeler
gauge. The minimum permitted clearance is 0.001 inch (0.03 mm). The maximum permitted clearance is 0.0027
inch (0.069 mm).
10.
Secure the pinion shafts (1) with lockwire (C-405), as shown in View A.
11.
Secure the nuts (3) with lockwire (C-405), as shown in View B.
Applicable to: ALL
412-A-63-10-00-12A-710A-B
ECCN EAR99
28 OCT 2024 Page 00162-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00018-A-001-01
Figure 1. Upper Planetary Assembly (Sheet 1 of 3)
412-A-63-10-00-12A-710A-B
Applicable to: ALL
Page 00162-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00019-A-001-01
Figure 1. Upper Planetary Assembly (Sheet 2 of 3)
Applicable to: ALL
412-A-63-10-00-12A-710A-B
ECCN EAR99
28 OCT 2024 Page 00162-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00020-A-002-01
Figure 1. Upper Planetary Assembly (Sheet 3 of 3)
412-A-63-10-00-12A-710A-B
Applicable to: ALL
Page 00162-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Lower Planetary Assembly - Disassembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Guide Pin
Alignment Fixture
Holding Fixture
Shaft Guide
T101332
T101572
T101573
T101574
1
1
1
1
Remarks
Procedure
1.
Cut and remove lockwire.
2.
Install the holding fixture (T101573) in a vise. Put the lower planetary on the holding fixture, as shown in Figure 1.
3.
Remove the four nuts (10).
4.
Loosen the four nuts (9) but keep the nuts tight enough to hold the planetary rigid during removal of the shafts (17).
5.
Remove the planetary from the holding fixture.
6.
Put the planetary on the backup ring (204-240-009-001 or 204-040-009-1 PAT-2D).
7.
Thread the shaft guide (T101574) into the shaft (17).
8.
Press the shaft (17) out of the planetary. Hold the pinion gear (12) to prevent it from falling out of the planetary.
9.
Put the guide pin (T101332) into the inner race (15). Remove the shaft (17) from the shaft guide.
10.
Tap the pinion gear (12), with a rubber mallet, out of the side opening between the plates (2 and 8). Hold the thrust
washers (11 and 16) in place to prevent the rollers (14) from falling out.
BEARING ROLLERS ARE A MATCHED SET. MAKE SURE THEY ARE KEPT TOGETHER.
11.
Remove the thrust washers (11 and 16), rollers (14), retainer (13), and inner race (15) from the pinion gear (12).
Keep the rollers together as a matched set.
12.
Remove the three remaining pinion gears (12) in the same manner outlined in Step 7. through Step 11..
PLATES ARE A MATCHED SET AND NOT INTERCHANGEABLE. MAKE SURE THEY ARE KEPT
TOGETHER.
13.
Remove the four nuts (9) and the bolts (1). Separate the plates (2 and 8) and the spider (4). Keep the plates
together as a matched set.
14.
Tap all the spacers (3 and 7) out of the plates (2 and 8) with a rubber mallet.
15.
Remove the four retaining rings (6).
16.
Put the spider (4) in the base of the alignment fixture (T101572) , as shown in Figure 1
17.
Put the guide (T101572-5) and the punch (T101572-9) in position, as shown in Figure 1
18.
Press the bearing (5) out of the spider (4). Discard the bearing.
19.
Remove and discard the three remaining bearings (5) in the same manner outlined in Step 17. and Step 18..
20.
Remove the spider (4) from the alignment fixture (T101572).
Applicable to: ALL
412-A-63-10-00-13A-530A-B
ECCN EAR99
31 MAY 2023 Page 00163-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00022-A-001-01
Figure 1. Lower Planetary Assembly (Sheet 1 of 3)
412-A-63-10-00-13A-530A-B
Applicable to: ALL
Page 00163-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00023-A-001-01
Figure 1. Lower Planetary Assembly (Sheet 2 of 3)
Applicable to: ALL
412-A-63-10-00-13A-530A-B
ECCN EAR99
31 MAY 2023 Page 00163-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00024-A-001-01
Figure 1. Lower Planetary Assembly (Sheet 3 of 3)
412-A-63-10-00-13A-530A-B
Applicable to: ALL
Page 00163-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Lower Planetary Assembly - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Corrosion preventive compound
Drycleaning solvent
Solvent
Clean cloth
C-105
C-304
C-334
C-516
AR
AR
AR
AR
Remarks
Procedure
1.
Clean all the parts with drycleaning solvent (C-304). Use a soft bristle brush to dislodge stubborn deposits if desired.
All parts other than the bearings may be cleaned with solvent (C-334) by vapor degreasing.
DO NOT ALLOW BEARINGS TO SPIN WHILE DRYING.
2.
Dry the parts with a clean cloth (C-516) or dry filtered compressed air.
DO NOT HANDLE UNOILED BEARINGS WITH BARE HANDS.
NOTE
Parts treated per the following step may be left covered in indoor storage for approximately 150 hours
without being affected by corrosion.
3.
Immediately after cleaning parts with solvent, gently agitate the parts in corrosion preventive compound (C-105) and
allow to drain dry.
Applicable to: ALL
412-A-63-10-00-13A-258A-B
ECCN EAR99
31 MAY 2023 Page 00164-1
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-13A-258A-B
Applicable to: ALL
Page 00164-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Lower Planetary Assembly - Inspection
Procedure
NOTE
Limits charts are provided to show the necessary fit between mating parts. It is not intended that all
dimensions listed on the limits charts be checked as in prescribed overhaul procedure; however, parts
that show evidence of wear or physical damage must be checked dimensionally.
1.
Do the visual inspection of the parts shown in Figure 1. If any parts show evidence of wear or physical damage when
inspected during subsequent steps, measure the dimensions to determine whether the part is permitted.
2.
Do the inspection of the wear pattern in the teeth of all lower planetary pinions. Refer to Figure 2 for examples of
acceptable and unacceptable wear patterns.
3.
Do the inspection of the teeth on the pinion gears (12, Figure 3) and the splines on the spider (4) for nicks, dents,
chipped, and/or broken, and worn teeth. Any anomaly felt with a 0.020-inch (0.51-mm) spherical radius probe is
unacceptable.
4.
Do the inspection of the following parts by the magnetic particle inspection. Demagnetize the parts after the magnetic
particle inspection. Refer to Table 2 and the BHT-ALL-SPM, Standard Practices Manual for the procedure.
Figure 3INDEX NUMBER
NOMENCLATURE
1
Bolt
2
Plate
4
Spider
7
Spacer
8
Plate
9
Nut
10
Nut
12
Pinion Gear
13
Retainer
15
Inner Race
17
Shaft
Table 2. Magnetic Particle Inspection
PART NUMBER
NOMENCLATURE
ITEM AND FIGURE
SET UP AND MAGNETIZATION CURRENT REQUIREMENTS
HP/EP LOWER PLANETARY ASSEMBLY (204-040-784-109 AND -111)
204-040-786-001
Plate Set
2 and 8, Figure 3
SET UP:
Place part over a 2.0-inches (51-mm) diameter central conductor.
Current for primary diameters, magnetize at 4760 amps.
Large I.D. of part: Magnetize at six approximately equally spaced radial locations on central conductor.
SET: 5 TURN COIL SHOT:
Disc-shaped portion of part: Place part in bottom of coil.
Magnetize at 3000 amps.
Rotate part 1/4 turn and repeat.
412-040-785-101, -103
Spider
4, Figure 3
Applicable to: ALL
412-A-63-10-00-13A-280A-B
ECCN EAR99
31 MAY 2023 Page 00165-1
BHT-412-CRO
Table 2. Magnetic Particle Inspection (continued)
SET UP:
Place part over a 2.0-inch (51-mm) diameter central conductor at four inside locations between legs.
Current for body diameter, magnetize at 2200 amps.
SET UP:
Place part over a 2-inch (51-mm) diameter central conductor at each leg.
Current for each leg shot, magnetize at 4800 amps.
SET UP:
Place part over 0.7-inch (18-mm) diameter central conductor through each leg hole.
Current for each leg hole, magnetize at 1200 amps.
SET UP: 5 TURN COIL SHOT:
Place part flat in coil, legs up, with two legs on coil axis.
Magnetize at 3000 amps.
Rotate part 1/4 turn and repeat coil shot.
DEMAGNETIZATION AND POST INSPECTION CLEANING:
Carry out demagnetization and post inspection cleaning of spider as per BHT-ALL-SPM, Chapter 6..
204-040-130-005
Shaft
17, Figure 3
SET UP:
Place part over a 0.7-inch (18-mm) diameter central conductor.
Current for primary diameters, magnetize at 1250 amps.
Optional current for secondary diameters, magnetize at 848 amps.
Omit coil shot.
204-040-131-001
Nut
10, Figure 3
SET UP:
Place part over a 0.5-inch (13-mm) diameter central conductor.
Current for primary diameters, magnetize at 1340 amps.
Optional current for secondary diameters, magnetize at 742 amps.
Omit coil shot.
204-040-132-101
Inner Race
15, Figure 3
SET UP:
Place part over a 1.0-inch (25-mm) diameter central conductor.
Current for primary diameters, magnetize at 2000 amps.
SET UP: 5 TURN COIL SHOT:
Place part in bottom of coil such that the long axis of the part is 90° to the direction of the current flow through the coil.
Magnetize at 3000 amps.
205-040-233-105
412-A-63-10-00-13A-280A-B
Applicable to: ALL
Page 00165-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Table 2. Magnetic Particle Inspection (continued)
Pinion Gear
12, Figure 3
SET UP:
Place part over a 2.0-inches (51-mm) diameter central conductor.
Current for primary diameters, magnetize at 2170 amps.
Omit coil shot.
212-040-789-101
Spacer
3 and 7, Figure 3
SET UP:
Place part over a 0.5-inch (13-mm) diameter central conductor.
Current for primary diameters, magnetize at 1100 amps.
Omit coil shot.
212-040-782-101
Bolt
1, Figure 3
SET UP: 5 TURN COIL SHOT:
Hold part in bottom of coil with long axis parallel to coil axis.
Magnetize at 3000 amps.
212-040-783-101
Nut
9, Figure 3
SET UP:
Place part over a 0.5-inch (13-mm) diameter central conductor.
Current for primary diameters, magnetize at 1140 amps.
Omit coil shot.
LOWER PLANETARY ASSEMBLY (204-040-784-101 AND -107)
204-040-785-003
Spider
4, Figure 3
SET UP:
Place part over a 2.0-inches (51-mm) diameter central conductor at four inside locations between legs.
Current for body diameter, magnetize at 2200 amps.
SET UP:
Place part over a 2.0-inches (51-mm) diameter central conductor at each leg.
Current for each leg shot, magnetize at 4800 amps.
SET UP:
Place part over a 0.7-inch (18-mm) diameter central conductor through each leg hole.
Current for each leg hole, magnetize at 1200 amps.
SET UP: 5 TURN COIL SHOT:
Place part flat in coil, legs up, with two legs on coil axis.
Magnetize at 3000 amps.
Rotate part 1/4 turn and repeat coil shot.
DEMAGNETIZATION AND POST INSPECTION CLEANING:
Applicable to: ALL
412-A-63-10-00-13A-280A-B
ECCN EAR99
31 MAY 2023 Page 00165-3
BHT-412-CRO
Table 2. Magnetic Particle Inspection (continued)
Carry out demagnetization and post inspection cleaning of spider as per BHT-ALL-SPM, Chapter 6.
412-040-785-101
Spider
4, Figure 3
SET UP:
Place part over a 2.0-inches (51-mm) diameter central conductor at four inside locations between legs.
Current for body diameter, magnetize at 2200 amps.
SET UP:
Place part over a 2-inch (51-mm) diameter central conductor at each leg.
Current for each leg shot, magnetize at 4800 amps.
SET UP:
Place part over 0.7-inch (18-mm) diameter central conductor through each leg hole.
Current for each leg hole, magnetize at 1200 amps.
SET UP: 5 TURN COIL SHOT:
Place part flat in coil, legs up, with two legs on coil axis.
Magnetize at 3000 amps.
Rotate part 1/4 turn and repeat coil shot.
DEMAGNETIZATION AND POST INSPECTION CLEANING:
Carry out demagnetization and post inspection cleaning of spider as per BHT-ALL-SPM, Chapter 6.
212-040-789-101
Spider
3 and 7, Figure 3
204-040-786-001
Plate Set
2 and 8, Figure 3
204-040-130-005
Shaft
17, Figure 3
204-040-131-001
Nut
10, Figure 3
205-040-233-001
Pinion Gear
12, Figure 3
205-040-233-101
Pinion Gear
12, Figure 3
204-040-132-001
Inner Race
15,Figure 3
212-040-782-101
Bolt
1, Figure 3
SET UP: 5 TURN COIL SHOT:
Place part in bottom of coil with long axis parallel to coil axis.
Magnetize at 3000 amps.
212-040-783-101
Nut
9, Figure 3
SET UP:
412-A-63-10-00-13A-280A-B
Applicable to: ALL
Page 00165-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Table 2. Magnetic Particle Inspection (continued)
Place part over a 0.5-inch (13-mm) diameter central conductor.
Current for primary diameters, magnetize at 1140 amps.
Ignore coil shot.
NOTES:
1. Magnetization currents given are applicable to magnetic particle inspection devices that use Direct Current (DC) . If an
Alternating Current (AC) apparatus is used, adjust the current as follows: AC= 0.667 x DC.
2. Ferrous parts that need magnetic particle inspection that are not recorded in the attached material, are to be examined with
the general procedures given in ASTM E1444 standard practices (BHT-ALL-SPM, Chapter 6, Standard Practices Manual).
3. Part numbers listed apply to all successive dash numbers for that component unless otherwise specified.
5.
Do the inspection of the retainer (13) 204-040-133 by the fluorescent penetrant method. (BHT-ALL-SPM, Standard
Practices Manual).
6.
Do the inspection of the retainers (13), all part numbers, for embedded bearing chips or other steel particles in the tang
on the retainers. Retainers with embedded chips and/or mechanical damage that can be detected visually are not
permitted. Retainers that are chipped up to 0.020 inch (0.51 mm) in depth in the area shown in Figure 3 are permitted.
7.
Inspect the inner races (15) and rollers (14) for spalling, scoring, pitting, and brinelling, indentations, and corrosion.
Damage that can be detected visually, and with a 0.020-inch (0.51-mm) spherical radius probe, is not permitted. Light
scoring on the inner races in the area contacted by the retainers (13) is permitted.
Applicable to: ALL
412-A-63-10-00-13A-280A-B
ECCN EAR99
31 MAY 2023 Page 00165-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00149-A-001-01
Figure 1. Lower Planetary Assembly - Wear Limits (Sheet 1 of 1)
412-A-63-10-00-13A-280A-B
Applicable to: ALL
Page 00165-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00150-A-001-01
Figure 2. Lower Planetary Assembly - Wear Patterns (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-13A-280A-B
ECCN EAR99
31 MAY 2023 Page 00165-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00022-A-001-01
Figure 3. Lower Planetary Assembly (Sheet 1 of 3)
412-A-63-10-00-13A-280A-B
Applicable to: ALL
Page 00165-8 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00023-A-001-01
Figure 3. Lower Planetary Assembly (Sheet 2 of 3)
Applicable to: ALL
412-A-63-10-00-13A-280A-B
ECCN EAR99
31 MAY 2023 Page 00165-9
BHT-412-CRO
ICN-412-A-631000-B-97499-00024-A-001-01
Figure 3. Lower Planetary Assembly (Sheet 3 of 3)
412-A-63-10-00-13A-280A-B
Applicable to: ALL
Page 00165-10 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Lower Planetary Assembly - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
India stone
C-464
AR
Remarks
Procedure
1.
Polish out minor damage in the teeth of the pinion gear (12, Figure 1) and the splines of the spider (4) with a fine
india stone (C-464).
2.
If not previously accomplished, remove the four bearings (5) from the spider (4). Discard the old bearings. Polish
out any minor mechanical damage in the bore where the bearings were removed from the spider. If damage after
cleanup exceeds 0.020 inch (0.51 mm) in depth and/or damage extends over more than 20% of the area of the
bore, the spider is non-airworthy and nonrepairable.
3.
Remove superficial corrosion from the spider (4) by the same general procedure outlined in
412-A-63-10-00-12A-685A-B / 00161.
Applicable to: ALL
412-A-63-10-00-13A-685A-B
ECCN EAR99
31 MAY 2023 Page 00166-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00022-A-001-01
Figure 1. Lower Planetary Assembly (Sheet 1 of 3)
412-A-63-10-00-13A-685A-B
Applicable to: ALL
Page 00166-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00023-A-001-01
Figure 1. Lower Planetary Assembly (Sheet 2 of 3)
Applicable to: ALL
412-A-63-10-00-13A-685A-B
ECCN EAR99
31 MAY 2023 Page 00166-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00024-A-001-01
Figure 1. Lower Planetary Assembly (Sheet 3 of 3)
412-A-63-10-00-13A-685A-B
Applicable to: ALL
Page 00166-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Lower Planetary Assembly - Assembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Guide Pin
Alignment Fixture
Holding Fixture
Shaft Guide
T101332
T101572
T101573
T101574
1
1
1
1
Remarks
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Drycleaning solvent
Lockwire
Abrasive cloth or paper
C-304
C-405
C-406
AR
AR
AR
Remarks
Procedure
DO NOT HANDLE UNOILED PARTS WITH BARE HANDS.
1.
Inspect the new bearings (5, Figure 1) for sharp edges at the outer diameter of the chamfer. Polish sharp edges
lightly with fine abrasive cloth or paper (C-406). Make sure you don’t damage the bearings. Clean the bearings with
drycleaning solvent (C-304). Coat the bearings with the type of oil used in the transmission and allow to drain.
DO NOT EXCEED THE MAXIMUM ALLOWABLE TEMPERATURE WHEN YOU HEAT A PART OR
DAMAGE TO THE PART MAY OCCUR.
2.
Put the spider (4) in the base (T101572-3) of the alignment fixture (T101572), as shown in View C. Heat the spider to
200°F (93°C) maximum.
3.
Put the new bearing (5), drive (T101572-7), and guide (T101572-5) on the spider (4). Press the bearing into position.
Press the remaining three bearings into the spider.
4.
Install the four retaining rings (6).
5.
Press the four spacers (3) into alternate holes in the plate (2). Support the plate set in the area adjacent to the
hole during pressing operations.
6.
Locate the V-mark on the plates (2 and 8). These marks must be aligned when the planetary is assembled. Index the
four holes in the plate (8) to match the holes in the plate (2) where the spacers (3) were installed at the preceding step.
7.
Press the four spacers (7) into the plate (8) in the intended holes. Support the plate in the areas adjacent to the hole
during the pressing operations.
8.
Put the plate (8) with flange down as illustrated. Put the spider (4) on the plate (8). Put the plate (2) on the spider (4)
with flange up as illustrated. Align the V-marks.
9.
Apply the same oil as used in the transmission under the heads and on the threads of the four bolts (1).
10.
Install the four bolts (1) and the nuts (9). Tighten snugly, but do not torque at this time.
11.
Put the planetary parts assembled in the preceding steps on the backup ring (204-240-009-001 or 204-040-009-1
PAT-2D).
Applicable to: ALL
412-A-63-10-00-13A-710A-B
ECCN EAR99
28 OCT 2024 Page 00167-1
BHT-412-CRO
MAKE SURE THAT BEARING ROLLERS (14) ARE A MATCHED SET. ALL THE ROLLERS IN A SET
MUST BE FROM SAME MANUFACTURER. CHECK MANUFACTURER'S IDENTIFICATION MARK ON
END OF EACH ROLLER. ALSO, INDIVIDUAL ROLLERS ARE NOT INTERCHANGEABLE. IF ONE OR
MORE ROLLERS OF A SET FAILS TO PASS INSPECTION, THE ENTIRE SET MUST BE REPLACED.
ROLLER SETS WITH DIFFERENT DASH NUMBERS MAY BE USED IN THE SAME PLANETARY
ASSEMBLY, BUT ALL THE ROLLERS IN A SET FOR ONE PLANETARY PINION MUST BE OF SAME
DASH NUMBER.
12.
Assemble the pinion gear (12), retainer (13), inner race (15), rollers (14), and thrust washers (11 and 16) on the
planetary guide pin (T101332).
13.
Install the shaft guide (T101574) in the shaft (17).
14.
Put the pinion gear (12) and parts assembled in Step 12. in the planetary. Align the holes for the shaft (17). Make
sure the planetary is properly supported on the backup ring (204-240-009-001 or 204-040-009-1 PAT-2D). Press
the shaft into position. Catch the guide pin (T101332) as it is pushed out the bottom. Make sure that shaft is fully
seated on the plate (2).
15.
Remove the shaft guide (T101574) from the shaft (17).
16.
Install the three remaining pinion gears (12) in the same manner outlined in Step 12. through Step 15..
17.
Apply the same oil as used in the transmission on the threads of the four nuts (10). Install the nuts on the shafts
(17). Do not torque the nuts at this time.
18.
Remove the planetary from the backup ring (204-240-009-001 or 204-040-009-1 PAT-2D).
19.
Install the holding fixture (T101573) in a vise. Put the planetary on the holding fixture, as shown in View A.
20.
Torque the four nuts (9) 35 to 45 foot-pounds (47 to 61 Nm) in diametrical sequence.
21.
Torque the four nuts (10) 60 to 80 foot-pounds (81 to 108 Nm) in diametrical sequence.
22.
Rotate the four pinion gears (12) manually and check for binding. Binding that can be detected by feel is not permitted.
23.
Secure the nuts (9 and 10) in pairs with lockwire (C-405).
24.
Secure the bolts (1) and the shaft (17) in pairs with lockwire (C-405).
412-A-63-10-00-13A-710A-B
Applicable to: ALL
Page 00167-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00022-A-001-01
Figure 1. Lower Planetary Assembly (Sheet 1 of 3)
Applicable to: ALL
412-A-63-10-00-13A-710A-B
ECCN EAR99
28 OCT 2024 Page 00167-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00023-A-001-01
Figure 1. Lower Planetary Assembly (Sheet 2 of 3)
412-A-63-10-00-13A-710A-B
Applicable to: ALL
Page 00167-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00024-A-001-01
Figure 1. Lower Planetary Assembly (Sheet 3 of 3)
Applicable to: ALL
412-A-63-10-00-13A-710A-B
ECCN EAR99
28 OCT 2024 Page 00167-5
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-13A-710A-B
Applicable to: ALL
Page 00167-6 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Main Input Gear Quill (204-040-362-103) - Disassembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Power Wrench Kit
Anchor Plate
Socket
T100965
T100968
T101303
1
1
1
Remarks
Procedure
NOTE
SN: 36020-36999 or 37002-37999 or SN: 38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed:
Refer to 412-A-63-10-00-15A-530A-B / 00173.
1.
Remove the 24 bolts (1, Figure 1) and the washers (14).
2.
Carefully tap the gear support case (2) to remove it from the collector (13).
3.
Remove the shims (3 and 4) and mark the shims for installation at the same location.
4.
Remove the collector (13).
5.
Remove the screws (5) and the lock ring (6).
6.
Put the socket (T101303) on the nut (7).
7.
Install the anchor plate (T100968) and the power wrench kit (T100965) on the shaft (11) and loosen the nut (7).
8.
Remove the tools and the nut (7).
BEARINGS (8) MUST BE RIGIDLY SUPPORTED ON THE INNER RACE AROUND THE FULL
CIRCUMFERENCE SO THAT THE OUTER RACES ARE NOT LOADED DURING BEARING
REMOVAL. INADEQUATE SUPPORT WILL RESULT IN DAMAGED BEARINGS AND/OR SHAFT.
BEARINGS ARE A MATCHED SET AND MUST BE RETAINED OR REPLACED IN PAIRS.
9.
Support the duplex bearings (8) on the inner race and press the shaft out of the bearing. Keep the bearings together
as a matched set. Mark the bearings for assembly.
10.
Remove the bearing retainer plate (9).
11.
Remove the 32 bolts (10) from the flange of shaft (11).
12.
Carefully tap or press the spiral bevel gear (12) out of the shaft.
Applicable to: ALL
412-A-63-10-00-14A-530A-B
ECCN EAR99
28 OCT 2024 Page 00168-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00047-A-001-01
Figure 1. Main Input Gear Quill (204-040-362-103) (Sheet 1 of 1)
412-A-63-10-00-14A-530A-B
Applicable to: ALL
Page 00168-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Main Input Gear Quill (204-040-362-103) - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Corrosion preventive compound
Drycleaning solvent
Clean cloth
Solvent
C-105
C-304
C-516
C-334
AR
AR
AR
AR
Remarks
Procedure
NOTE
SN: 36020-36999 or 37002-37999 or SN: 38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed:
Refer to 412-A-63-10-00-15A-258A-B / 00174.
1.
Inspect the parts for corrosion damage to holes before cleaning. No structural damage to holes is permitted.
2.
Remove the sealant from the gear support case with a plastic scraper.
3.
Clean the quill parts with drycleaning solvent (C-304). Use a soft bristle brush to dislodge deposits. All parts except
bearings may be cleaned with solvent (C-334) by vapor degreasing.
DO NOT ALLOW BEARINGS TO SPIN WHILE DRYING.
4.
Dry the parts with a clean cloth (C-516) or dry filtered compressed air.
DO NOT HANDLE UNOILED BEARINGS WITH BARE HANDS.
NOTE
Parts treated per the following step may be left covered in indoor storage for approximately 150 hours
without being affected by corrosion.
5.
Coat the bearings with corrosion preventive compound (C-105) immediately after cleaning (BHT-ALL-SPM, Standard
Practices Manual).
Applicable to: ALL
412-A-63-10-00-14A-258A-B
ECCN EAR99
28 OCT 2024 Page 00169-1
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-14A-258A-B
Applicable to: ALL
Page 00169-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Main Input Gear Quill (204-040-362-103) - Inspection
Procedure
NOTE
SN: 36020-36999 or 37002-37999 or SN: 38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed:
Refer to 412-A-63-10-00-15A-280A-B / 00175.
NOTE
Wear limits are provided to show the required fit between mating parts. It is not intended that all
dimensions be checked as a prescribed overhaul procedure; however, parts that show evidence of wear
or physical damage must be checked dimensionally.
1.
Inspect all the parts visually for damage and excessive wear.
2.
Inspect the gear support case (2, Figure 1) for corrosion and for a loose bearing liner as follows:
2.1.
The maximum permitted depth of pitting in Area A (Figure 2) is 0.020 inch (0.51 mm), except as defined in Step 2.2..
No more than 40% of the area within any 1.0 square inch (645.2 mm2) or 20% of total area of any surface or diameter
may be pitted. Inspect Area B carefully prior to any corrosion removal for evidence of corrosion in the bolt holes and
between the bearing liner and case. Any evidence of corrosion in the bolt holes or between the liner and case is
cause for rejection of the part.
2.2.
The maximum permitted depth of pitting on the lower flange only, in area 1/32 (0.03125) inch (0.7938 mm) below
radius to the packing groove in Area A (Figure 2), is 0.030 inch (0.76 mm) and is limited to no more than 40% of
the area within any 1.0 square inch (645.2 mm2) or 20% of the total area. Isolated pits in Area A are permitted to a
maximum depth of 0.060 inch (1.52 mm), provided the total area pitted in excess of 0.030 inch (0.762 mm) does not
exceed 2% of the area within any 1.0 square inch (645.2 mm2) or 0.50% of the total area of any surface or diameter.
3.
Inspect the nut (7, Figure 1) for damaged threads.
4.
Inspect the duplex bearings (8) for spalling, scoring, flaking, corrosion, and roughness when rotated.
5.
Inspect the bearing retainer plate (9) for damaged threads.
6.
Inspect the shaft (11) for spalling, scoring, pitting, flaking, corrosion, and indentations on the bearing contact surfaces.
Inspect the splines for pitted, chipped, or excessively worn teeth. Inspect the threads for defects. The maximum
permitted depth of nicks, dents, and scratches on the spline teeth is 0.030 inch (0.76 mm) and is limited to no more
than 10% of the tooth within 20% of the tooth length. The tooth length is the one that contacts the mating surface.
7.
Inspect the spiral bevel gear (12) for spalled, scuffed, chipped, or dented teeth.
8.
Inspect the mating surfaces of the shaft (11) and the spiral bevel gear (12) for fretting damage. The maximum
permitted depth of fretting (pitting) is 0.0005 inch (0.013 mm). Pitting of measurable depth is permitted only in the
area on the gear or the shaft surface outside of the diameter of the bolt holes and is not permitted within 0.10
inch (2.5 mm) of the edge of a bolt hole.
9.
Inspect the spiral bevel gear (12) for pitting or corrosion damage as follows:
9.1.
Pitting of any magnitude resulting from surface fatigue during operation is not permitted. This may appear as only a
fine line of pin holes near the pitch diameter and be detectable only with a side light source and a probe point of
approximately 0.001 inch (0.03 mm) radius. A more severe example of this is shown in Figure 3, Detail B. Minor
pitting resulting from corrosion is permitted within following limits:
9.1.1.
No more than 0.001 inch (0.03 mm) deep, and no more than 0.040 inch (1.02 mm) wide, or 0.080 inch (2.03 mm) long.
9.1.2.
No more than 0.002 inch (0.05 mm) deep and no more than 0.040 inch (1.02 mm) wide or 0.100 inch (2.54 mm) long
and located on the outer (i.e., adjacent to the heel) half of the face of the tooth and above the pitch line, or located
outside of the wear pattern and outside of the root radius.
9.2.
Surface roughness detectable by drawing a probe along the tooth in a profile direction is cause for rejection if pitting
occurred on the mating member.
9.3.
Any grinding scratches around which pitting or other damage occurs are not permitted.
Applicable to: ALL
412-A-63-10-00-14A-280A-B
ECCN EAR99
28 OCT 2024 Page 00170-1
BHT-412-CRO
9.4.
Nicks, cuts, or dents caused by handling or by foreign material going through mesh during operation are permitted
provided they are no more than 0.003 inch (0.08 mm) deep and are not more than 0.020 inch (0.51 mm) across in any
direction, and cannot be felt with a 0.020-inch (0.51-mm) spherical radius probe.
NOTE
The following visual evaluation shall use supplemental lighting.
9.5.
Bottom of the holes shall be free of burrs, tears, gouges, or compacted chips. The disposition shall be determined by
visual comparison of the spiral bevel gear holes with Figure 4.
10.
Inspect the following parts by magnetic particle inspection (Code M) or fluorescent penetrant inspection (Code F), as
applicable. Demagnetize parts after magnetic particle inspection. Refer to Table 2 and the BHT-ALL-SPM, Standard
Practices Manual for the procedure.
Figure 1INDEX NUMBER
NOMENCLATURE
CODE
2
Gear Support Case
F
7
Nut
M
9
Bearing Retainer Plate
M
11
Shaft
M
12
Spiral Bevel Gear
M
Table 2. Magnetic Particle Inspection
PART NUMBER
NOMENCLATURE
ITEM AND FIGURE
SET UP AND MAGNETIZATION CURRENT REQUIREMENTS
MAIN INPUT GEAR QUILL (204-040-362-103)
204-040-324-005
Shaft
11, Figure 1
SET UP:
Place part over a 2-inch diameter central conductor.
Current for primary diameters, magnetize at 2500 amps.
Rotate part 180° and magnetize at 2500 amps.
SET UP: 5 TURN COIL SHOT:
Place part in bottom of coil such that the long axis of the part is 90° to the axis of the coil.
Magnetize at 2600 amps.
204-040-701-103
Spiral Bevel Gear
12, Figure 1
SET UP:
Place part over a 2-inch diameter central conductor.
Current for primary diameters, magnetize at 4140 amps.
Large I.D. of part: Magnetize at five approximately equally spaced radial locations on central conductor.
SET UP: 5 TURN COIL SHOT:
Disc-shaped portion of part: Place part in bottom of coil.
Magnetize at 3000 amps.
Rotate part 1/4 turn and repeat.
204-040-357-007
Bearing Retainer Plate
9, Figure 1
SET UP:
412-A-63-10-00-14A-280A-B
Applicable to: ALL
Page 00170-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Table 2. Magnetic Particle Inspection (continued)
Place part over a 2-inch diameter central conductor.
Current for primary diameters, magnetize at 2750 amps.
Large I.D. of part: Magnetize at three approximately equally spaced radial locations on central conductor.
SET UP: 5 TURN COIL SHOT:
Disc-shaped portion of part: Place part in bottom of coil.
Magnetize at 3000 amps.
Rotate part 1/4 turn and repeat.
NOTES:
1. Magnetization currents provided are applicable to magnetic particle inspection apparatus using Direct Current (DC) . If an
Alternating Current (AC) apparatus is used, adjust the current as follows: AC= 0.667 x DC.
2. Ferrous parts requiring magnetic particle inspection that are not addressed in the attached material, are to be inspected in
accordance with the general procedures outlined in ASTM E1444 standard practices (BHT-ALL-SPM, Chapter 6, Standard
Practices Manual).
3. Part numbers listed apply to all successive dash numbers for that component unless otherwise specified.
NOTE
Refer to Step 11. and Step 12. for special inspection procedures for the shaft (11).
11.
Inspect the shaft (11, Figure 1) by magnetic particle method. The shaft must be inspected by all of the following steps
using wet continuous method. The use of fluorescent coated particles with ultra violet light is mandatory. The length
of any indication shall be determined by the residual method of magnetization.
NOTE
If AC magnetic particle inspection equipment is used, use 60% of DC amps specified.
11.1.
Thoroughly degrease the gear.
11.2.
Magnetize the gear by placing the shaft between the contact heads of the inspection equipment. Pass approximately
2000 amps of DC current through the gear.
11.3.
Inspect the gear completely, inside and outside, for indications.
11.4.
Place the gear inside the coil such that the long axis of the gear is approximately 90° to the direction of the current
flow in the coil. Magnetize the gear with approximately 1000 amps of DC current.
11.5.
Inspect the shaft completely for indications.
11.6.
After completion of the inspection, demagnetize the shaft and check with a compass or equivalent to ensure
demagnetization.
12.
Evaluate the defects noted during the magnetic particle inspection of the shaft (11) as follows (Figure 5):
12.1.
Indications interpreted as cracks are cause for rejection regardless of size or location.
12.2.
Surface or subsurface indications or stringers, shunts, non-metallic inclusions, bursts, laps, or seams are permitted
provided they are within all the following limits:
12.2.1.
Indications of defects parallel (±15°) to the long axis of the shaft are permitted, provided the length of the indication
does not exceed 0.125 inch (3.18 mm) and provided other limitations herein are not exceeded. Not more than two
such indications allowed in any 2.0 square inches (1290.3 mm2) of surface area.
12.2.2.
Circumferential indications, or indications more than 15° off the long axis of the shaft are permitted in Area B
(Figure 5) provided the lengthof the indications does not exceed 0.25 inch (6.4 mm). Not more than two such
indications shall be allowed in any 1.0 square inch (645.2 mm2) of surface area. Indications on the bearing journal, in
Area B, are permitted if the length of the indication does not exceed 0.0625 inch (1.588 mm) in length and provided
the indication is 0.125 inch (3.18 mm) or more from the end of the bearing journal. Indications within 0.125 inch (3.18
mm) of the end of the bearing journal or that break over the end of the bearing journal are cause for rejection. No
more than four indications within the above limits, are allowed on each bearing journal.
Applicable to: ALL
412-A-63-10-00-14A-280A-B
ECCN EAR99
28 OCT 2024 Page 00170-3
BHT-412-CRO
12.2.3.
Circumferential indications, or indications that are more than 15° of the long axis of the shaft in Area A (Figure 5),
are cause for rejection.
12.2.4.
Indications more than 15° off the long axis, transverse or circumferential to the long axis, are permitted in the spline
areas provided they do not exceed 0.125 inch (3.18 mm) in length. Not more than one indication is allowed per tooth,
and not more than six to each spline area. All other indications in the spline area are cause for rejection.
12.2.5.
Indications in the threaded sections are cause for rejection regardless of size or location in Area A (Figure 5).
12.2.6.
Indications of subsurface discontinuities that break a transverse face shall not exceed 0.031 inch (0.79 mm) in
length or cross section.
12.2.7.
Indications or surface discontinuities that break over corners or run into fillets, splines, or threads, are cause
for rejection.
12.2.8.
Indications caused by a change in the section are permitted.
12.2.9.
Strong magnetic indications where considerable buildup is present, indicating that defect has considerable depth
and/or cross section, shall be cause for rejection regardless of location.
13.
Inspect the parts dimensionally and replace parts that do not fall within the inspection limits (Figure 6).
412-A-63-10-00-14A-280A-B
Applicable to: ALL
Page 00170-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00047-A-001-01
Figure 1. Main Input Gear Quill (204-040-362-103) (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-14A-280A-B
ECCN EAR99
28 OCT 2024 Page 00170-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00151-A-001-01
Figure 2. Main Input Gear Quill Case (204-040-386-001) - Damage Limits (Sheet 1 of 1)
412-A-63-10-00-14A-280A-B
Applicable to: ALL
Page 00170-6 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00152-A-001-01
Figure 3. Main Input Gear Quill (204-040-386-001) - Wear Patterns (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-14A-280A-B
ECCN EAR99
28 OCT 2024 Page 00170-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00153-A-001-01
Figure 4. Spiral Bevel Gear Mounting Holes (204-040-701) - Damage Limits (Sheet 1 of 1)
412-A-63-10-00-14A-280A-B
Applicable to: ALL
Page 00170-8 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00154-A-001-01
Figure 5. Main Input Gear Quill Shaft - Magnetic Inspection Areas (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-14A-280A-B
ECCN EAR99
28 OCT 2024 Page 00170-9
BHT-412-CRO
ICN-412-A-631000-B-97499-00155-A-001-01
Figure 6. Main Input Gear Quill - Wear Limits (Sheet 1 of 2)
412-A-63-10-00-14A-280A-B
Applicable to: ALL
Page 00170-10 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-01029-A-001-01
Figure 6. Main Input Gear Quill - Wear Limits (Sheet 2 of 2)
Applicable to: ALL
412-A-63-10-00-14A-280A-B
ECCN EAR99
28 OCT 2024 Page 00170-11
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-14A-280A-B
Applicable to: ALL
Page 00170-12 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Main Input Gear Quill (204-040-362-103) - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
India stone
C-464
AR
Remarks
Procedure
NOTE
SN: 36020-36999 or 37002-37999 or SN: 38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed:
Refer to 412-A-63-10-00-15A-685A-B / 00176.
1.
If small nicks, burrs, or scratches are visible, dress the splines and the gear with a fine india stone (C-464) (Figure 1).
2.
Repair minor damage to the bevel gears by lightly polishing with a fine india stone (C-464) to remove any material
that protrudes above the original ground surface.
3.
Replace the bevel gear support case that has corrosion damage that would affect its function or structural integrity.
Remove the corrosion in Area A (Figure 2) by acid bath (BHT-ALL-SPM, Standard Practices Manual).
4.
Blend the spline areas of the shaft (11, Figure 3) with a 0.060 inch (1.52 mm) minimum radius. After rework,
measure the spline wear, as shown in Figure 1. Also, polish the transferred material on the sun gear splines with a
fine india stone (C-464).
Applicable to: ALL
412-A-63-10-00-14A-685A-B
ECCN EAR99
28 OCT 2024 Page 00171-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00155-A-001-01
Figure 1. Main Input Gear Quill - Wear Limits (Sheet 1 of 2)
412-A-63-10-00-14A-685A-B
Applicable to: ALL
Page 00171-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-01029-A-001-01
Figure 1. Main Input Gear Quill - Wear Limits (Sheet 2 of 2)
Applicable to: ALL
412-A-63-10-00-14A-685A-B
ECCN EAR99
28 OCT 2024 Page 00171-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00151-A-001-01
Figure 2. Main Input Gear Quill Case (204-040-386-001) - Damage Limits (Sheet 1 of 1)
412-A-63-10-00-14A-685A-B
Applicable to: ALL
Page 00171-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00047-A-001-01
Figure 3. Main Input Gear Quill (204-040-362-103) (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-14A-685A-B
ECCN EAR99
28 OCT 2024 Page 00171-5
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-14A-685A-B
Applicable to: ALL
Page 00171-6 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Main Input Gear Quill (204-040-362-103) - Assembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Power Wrench Kit
Anchor Plate
Socket
T100965
T100968
T101303
1
1
1
Remarks
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Drycleaning solvent
Lockwire
C-304
C-405
AR
AR
Remarks
Procedure
NOTE
SN: 36020-36999 or 37002-37999 or SN: 38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed:
Refer to 412-A-63-10-00-15A-710A-B / 00177.
1.
Clean all the parts with drycleaning solvent (C-304) and drain.
NOTE
Refer to the BHT-412-MM for approved lubricants.
2.
Coat all the parts with the same oil used in the transmission and drain.
IT IS ESSENTIAL THAT UTMOST PRECISION BE USED WHEN ASSEMBLING THIS QUILL.
3.
Put the spiral bevel gear (12, Figure 1) on the shaft (11) with the holes aligned. Tap or press the gear on the flange.
4.
Install the bolts (10) into the shaft (11) and spiral bevel gear (12). Torque all the bolts evenly to 390 inch-pounds (44
Nm), then individually break the bolt torque, and retorque to 300 to 325 inch-pounds (34 to 37Nm).
5.
Secure the bolt heads in pairs with lockwire (C-405) around the heads, not over the tops.
6.
Check the duplex bearings (8) to confirm that the serial number is the same on both bearings. Hold the bearings
back-to-back, measure the width of the outer races and record as Dimension C (Figure 2).
7.
Determine the thickness of the shims (2 and 3, Figure 2) for the main input quill as follows:
NOTE
Determine the thickness of the shim (3) between the bearing and liner as outlined in Step 7.1. through
Step 7.3..
7.1.
Record the following dimensions.
Dim C
-
Measure width of bearing outer races (Step 6.).
Dim X
-
Etched on support case.
Dim Y
-
Etched on support case.
Dim R
-
Etched on shaft.
Dim S
-
0.0330 inch (0.838 mm) actual measured dimension.
Applicable to: ALL
412-A-63-10-00-14A-710A-B
ECCN EAR99
28 OCT 2024 Page 00172-1
BHT-412-CRO
7.2.
Dim T
-
Etched on bearing retainer plate.
Dim B
-
Given: 3.0610 to 3.0630 inch (77.749 to 77.800 mm)
Typical example:
I.
Dim B (average)
3.0620 inch (77.775 mm)
Dim Y
+1.4543 inch (36.939 mm)
Dimension: 4.5163 inch (114.714 mm)
II.
Dim R
1.3095 inch (33.261 mm)
Dim C
+1.7248 inch (+43.810 mm)
Dim X
+1.4520 inch (+36.881 mm)
Dimension: 4.4896 inch (114.036 mm)
III.
Dim I (above)
4.5163 inch (114.714 mm)
Dim II (above)
-4.4863 inch (-113.952 mm)
Required thickness for the shim
(3, Figure 2)
7.3.
Dimension: 0.0300 inch (0.762 mm)
Recheck computation of shim thickness.
NOTE
Determine thickness of the shim (2) between the case and bearing retainer as outlined in Step 7.4. through
Step 7.5..
7.4.
Typical example:
IV.
Shim determined at III
0.0300 inch (0.762 mm)
Dim C
+1.7248 inch (+43.810 mm)
Dimension: 1.7548 inch (44.572 mm)
V.
Dim T
0.2440 inch (6.198 mm)
Dim S
+0.0330 inch (+0.838 mm)
Dim Y
+1.4540 inches (+36.932 mm)
Pinch required, 0.001 to 0.005
inch (0.025 to 0.1270 mm)
+0.0030 inch (+0.076 mm)
Dimension: 1.7340 inch (44.044 mm)
VI.
Dim IV (above)
Dim V (above)
Required thickness for the shim
(2) 0.0208 inch(0.528 mm)
7.5.
1.7548 inches (44.572 mm)
-1.7340 inches (-44.044 mm)
Dimension: 0.0208 inch (0.528 mm) (use 0.021 shim)
Recheck computation of shim thickness.
MAKE SURE THAT BEARINGS ARE PROPERLY INSTALLED BACK-TO-BACK. MAKE SURE THAT
SHIMS (3 AND 4, Figure 1) ARE NOT DAMAGED DURING INSTALLATION OF BOLTS. MAKE SURE
THAT BOLTS (1 AND 10) ARE PROPERLY SECURED.
412-A-63-10-00-14A-710A-B
Applicable to: ALL
Page 00172-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
8.
Put the shim (3, Figure 1) in the liner of the gear support case (2).
9.
Put the duplex bearings (8) in the back-to-back position over the gear support case (2).
10.
Press the duplex bearings (8) into the gear support case (2).
11.
Put the shim (4) in position and install the collector (13) and the bearing retainer plate (9) with the bolts (1) and the
washers (14) under the bolt heads.
12.
Torque the bolts (1) evenly 20 to 25 inch-pounds (2.3 to 2.8 Nm) and secure in pairs with lockwire (C-405).
NOTE
The etched marks placed on the bearings by the bearing manufacturer mark the high point of the race
runout.
13.
Put the gear support case (2) on the shaft (11). Align vibro-etched 0 on ends of the inner races with index marks on
shaft.
NOTE
If the shaft (11) is being replaced, vibro-etch the index mark on the new shaft the same as on the old shaft.
14.
Press the duplex bearings (8) on the inner races to seat against the shoulder of the shaft (11).
15.
Install the nut (7).
16.
Put the socket (T101303) and the power wrench kit (T100965) over the nut (7).
17.
Install the anchor plate (T100968) on the shaft.
18.
Torque the nut (7) to the low side of 150 to 200 foot-pounds (203 to 271 Nm). This is 13.5 to 18 foot-pounds (18.3
to 24 Nm) on torque wrench when using the power wrench kit (T100965).
19.
Remove the tools as necessary to install the lock ring (6) on the nut (7). Adjust the torque, if necessary, by tightening
within the torque limits until the screw holes line up.
20.
Install the two screws (5) at opposite sides of the shaft and secure each to a hole in the edge of the lock ring
(6) with lockwire (C-405).
IT IS IMPERATIVE TO OBTAIN THE PROPER DIMENSION AS FAILURE TO DO SO WILL CAUSE
IMPROPER BACKLASH AND GEAR WEAR PATTERN.
21.
Check the assembly on the surface plate with a vernier height gauge and dial indicator. Measure Dimension B
(Figure 2) at several points approximately 90° apart. The measurements must be 3.0610 to 3.0630 inches (77.749
to 77.800 mm). If the dimension is not obtained, a damaged shim or a shim of incorrect thickness may be the
cause. Repeat Step 6. through Step 21..
22.
Check the bearings for free rotation.
Applicable to: ALL
412-A-63-10-00-14A-710A-B
ECCN EAR99
28 OCT 2024 Page 00172-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00047-A-001-01
Figure 1. Main Input Gear Quill (204-040-362-103) (Sheet 1 of 1)
412-A-63-10-00-14A-710A-B
Applicable to: ALL
Page 00172-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00156-A-001-01
Figure 2. Main Input Gear Quill (204-040-362-103) - Shimming (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-14A-710A-B
ECCN EAR99
28 OCT 2024 Page 00172-5
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-14A-710A-B
Applicable to: ALL
Page 00172-6 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Main Input Gear Quill (412-040-362-101, -103 and -105) - Disassembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Power Wrench Kit
Anchor Plate
Socket
Plate Set
T100965
T100968
T101303
T101921
1
1
1
1
Remarks
Procedure
1.
Remove the 24 bolts (4, Figure 1) and the washers (5).
2.
Carefully tap the gear support case (6) to remove it from the collector (9).
3.
Remove the shims (7) and mark the shims for installation at the same location.
4.
Remove the collector (9).
NOTE
Shims (10) are installed on top of the collector (9) on configuration 412-040-362-103 and -105, and under
the collector (9) on configuration 412-040-362-101.
5.
Remove the shims (10) and mark the shims for installation at the same location.
6.
Remove the screws (1) and the lock ring (2).
7.
Put the socket (T101303) on the nut (3).
8.
Install the anchor plate (T100968) and the power wrench kit (T100965) on the shaft of the gear assembly (12) and
loosen the nut (3).
9.
Remove the tools and the nut (3).
BEARINGS (8) MUST BE RIGIDLY SUPPORTED ON THE INNER RACE AROUND THE FULL
CIRCUMFERENCE TO PREVENT THE OUTER RACES ARE NOT LOADED DURING BEARING
REMOVAL. INADEQUATE SUPPORT WILL RESULT IN DAMAGED BEARINGS AND/OR SHAFT.
BEARINGS ARE A MATCHED SET AND MUST BE RETAINED OR REPLACED IN PAIRS.
10.
Support the duplex bearings (8) on the inner race with the plate set (T101921) and press the shaft out of the bearing.
Keep the bearings together as a matched set. Mark the bearings for assembly.
11.
Remove the bearing retainer plate (11).
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-15A-530A-B
28 OCT 2024 Page 00173-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00034-A-002-01
Figure 1. Main Input Gear Quill (412-040-362-101, -103 and -105) (Sheet 1 of 1)
412-A-63-10-00-15A-530A-B
Page 00173-2 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Main Input Gear Quill (412-040-362-101, -103 and -105) - Cleaning
Procedure
1.
Refer to 412-A-63-10-00-14A-258A-B / 00169 for the cleaning procedure of the main input gear quill.
Applicable to: SN: 36020-36999 or 37002-37999 or
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-15A-258A-B
28 OCT 2024 Page 00174-1
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Intentionally blank page
412-A-63-10-00-15A-258A-B
Page 00174-2 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Main Input Gear Quill (412-040-362-101, -103 and -105) - Inspection
Procedure
NOTE
Wear limits are provided to show the required fit between mating parts. It is not intended that all
dimensions be checked as a prescribed overhaul procedure; however, parts that show evidence of wear
or physical damage must be checked dimensionally.
1.
Inspect all the parts visually for damage and excessive wear.
2.
Inspect the gear support case (6, Figure 1) for corrosion and for a loose bearing liner (Figure 2).
3.
Inspect the nut (3, Figure 1) for damaged threads.
4.
Inspect the duplex bearings (8) for spalling, scoring, flaking, corrosion, and roughness when rotated.
5.
Inspect the bearing retainer plate (11) for damaged threads.
6.
Inspect the gear assembly (12), as shown in Figure 3.
7.
Inspect the following parts by magnetic particle inspection (Code M) or fluorescent penetrant inspection (Code F), as
applicable. Demagnetize parts after magnetic particle inspection. Refer to Table 2 and the BHT-ALL-SPM, Standard
Practices Manual for procedure.
Figure 1INDEX NUMBER
NOMENCLATURE
3
Nut
CODE
M
6
Gear Support Case
F
11
Bearing Retainer Plate
M
12
Gear Assembly
M
Table 2. Magnetic Particle Inspection
PART NUMBER
NOMENCLATURE
ITEM AND FIGURE
SET UP AND MAGNETIZATION CURRENT REQUIREMENTS
HP/EP MAIN INPUT GEAR QUILL (412-040-362-101)
204-040-357-007
Bearing Retainer Plate
11, Figure 1
SET UP:
Place part over a 2-inch diameter central conductor.
Current for primary diameters, magnetize at 2750 amps.
Large I.D. of part: Rotate on central conductor approximately three equally spaced radial locations.
SET UP: 5 TURN COIL SHOT:
Disc-shaped part: Place part flat in bottom of coil.
Magnetize at 3000 amps.
Rotate part 1/4 turn and repeat.
412-040-701-101/-107
Gear Assembly
12, Figure 1
SET UP:
Place part over a 2-inch diameter central conductor.
Current for primary diameters, magnetize at 2010 amps.
Inspect interior and exterior.
Magnetize a second time at 6000 amps.
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-15A-280A-B
28 OCT 2024 Page 00175-1
BHT-412-CRO
Table 2. Magnetic Particle Inspection (continued)
Inspect interior and exterior.
SET UP: 5 TURN COIL SHOT:
Hold part against inside bottom edge of coil with long axis of part parallel to coil axis.
Magnetize at 4500 amps.
Inspect interior and exterior surfaces.
NOTES:
1. Magnetization currents provided are applicable to magnetic particle inspection apparatus using Direct Current (DC) . If an
Alternating Current (AC) apparatus is used, adjust the current as follows: AC= 0.667 x DC.
2. Ferrous parts requiring magnetic particle inspection that are not addressed in the attached material, are to be inspected in
accordance with the general procedures outlined in ASTM E1444 standard practices (BHT-ALL-SPM, Chapter 6, Standard
Practices Manual).
3. Part numbers listed apply to all successive dash numbers for that component unless otherwise specified.
NOTE
Refer to Step 8. and Step 9. for special inspection procedures for the shaft (11).
8.
Inspect the gear (12, Figure 1) by magnetic particle method. The shaft must be inspected by all of the following steps
using the wet continuous method. The use of fluorescent coated particles with an ultraviolet light is mandatory. The
length of any indication shall be determined by the residual method of magnetization.
NOTE
If AC magnetic particle inspection equipment is used, use 60% of DC amps specified.
8.1.
Thoroughly degrease the gear.
8.2.
Magnetize the gear by placing the shaft between the contact heads of the inspection equipment. Pass approximately
2000 amps of DC current through the gear.
8.3.
Inspect the gear completely, inside and outside, for indications.
8.4.
Put the gear inside the coil such that the long axis of the gear is approximately 90° to the direction of current flow in
the coil. Magnetize the gear with approximately 1000 amps of DC current.
8.5.
Inspect the gear completely for indications.
8.6.
After completion of the inspection, demagnetize the gear and examine with a compass or equivalent to make sure
demagnetization.
9.
Evaluate the defects noted during the magnetic particle inspection of the gear (12) as follows (Figure 4):
9.1.
Indications interpreted as cracks are cause for rejection regardless of size or location.
9.2.
Surface or subsurface indications or stringers, shunts, non-metallic inclusions, bursts, laps or seams are permitted if
they are within all the following limits:
9.2.1.
Indications of defects parallel (±15°) to the long axis of the gear are permitted, if the length of the indication is
not more than 0.125 inches (3.18 mm) and if other limitations herein are not exceeded. Not more than two such
indications allowed in any 2.0 square inches (1290 mm2) of surface area.
9.2.2.
Circumferential indications, or indications more than 15° off the long axis of the gear are permitted in Area B (Figure 4)
if the length of the indications not more than 0.25 inches (6.4 mm). Not more than two such indications shall be
allowed in any 1.0 square inch (645.2 mm2) of surface area.
9.2.3.
Indications on the bearing journal, in Area B, are permitted if the length of the indication is not more than 0.0625 inches
(1.588 mm) and if the indication is 0.125 inches (3.18 mm) or more from the end of the bearing journal. Indications
within 0.125 inches (3.18 mm) of the end of the bearing journal or that break over the end of the bearing journal are
cause for rejection. No more than four indications within the above limits, are allowed on each bearing journal.
9.2.4.
Circumferential indications or indications that are more than 15° of the long axis of the gear in Area A (Figure 4)
are cause for rejection.
412-A-63-10-00-15A-280A-B
Page 00175-2 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
9.2.5.
Indications more than 15° off the long axis, transverse or circumferential to the long axis, are permitted in the spline
areas provided they do not exceed 0.125 inches (3.18 mm) in length. Not more than one indication is allowed per
tooth, and not more than six to each spline area. All other indications in the spline area are cause for rejection.
9.2.6.
Indications in the threaded sections are cause for rejection regardless of size or location in Area A (Figure 4).
9.2.7.
Indications of subsurface discontinuities that break a transverse face must not exceed 0.031 inches (0.79 mm) in
length or cross section.
9.2.8.
Indications or surface discontinuities that break over corners or run into the fillets, splines, or threads, are cause
for rejection.
9.2.9.
Indications caused by a change in section are permitted.
9.2.10.
Strong magnetic indications where considerable buildup is present, indicating that defect has considerable depth
and/or cross section must be cause for rejection regardless of location.
10.
Inspect the parts dimensionally and replace parts that do not fall within the inspection limits (Figure 5).
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-15A-280A-B
28 OCT 2024 Page 00175-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00034-A-002-01
Figure 1. Main Input Gear Quill (412-040-362-101, -103 and -105) (Sheet 1 of 1)
412-A-63-10-00-15A-280A-B
Page 00175-4 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00157-A-001-01
Figure 2. Main Input Gear Quill Case (412-040-385-101) - Damage Limits (Sheet 1 of 3)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-15A-280A-B
28 OCT 2024 Page 00175-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00158-A-001-01
Figure 2. Main Input Gear Quill Case (412-040-385-101) - Damage Limits (Sheet 2 of 3)
412-A-63-10-00-15A-280A-B
Page 00175-6 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00159-A-001-01
Figure 2. Main Input Gear Quill Case (412-040-385-101) - Damage Limits (Sheet 3 of 3)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-15A-280A-B
28 OCT 2024 Page 00175-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00160-A-001-01
Figure 3. Main Input Gear Quill (412-040-701-101/-107) - Damage Limits (Sheet 1 of 4)
412-A-63-10-00-15A-280A-B
Page 00175-8 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00161-A-001-01
Figure 3. Main Input Gear Quill (412-040-701-101/-107) - Damage Limits (Sheet 2 of 4)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-15A-280A-B
28 OCT 2024 Page 00175-9
BHT-412-CRO
ICN-412-A-631000-B-97499-00162-A-001-01
Figure 3. Main Input Gear Quill (412-040-701-101/-107) - Damage Limits (Sheet 3 of 4)
412-A-63-10-00-15A-280A-B
Page 00175-10 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00163-A-001-01
Figure 3. Main Input Gear Quill (412-040-701-101/-107) - Damage Limits (Sheet 4 of 4)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-15A-280A-B
28 OCT 2024 Page 00175-11
BHT-412-CRO
ICN-412-A-631000-B-97499-00165-A-001-01
Figure 4. Main Input Gear Quill - Magnetic Inspection Areas (Sheet 1 of 1)
412-A-63-10-00-15A-280A-B
Page 00175-12 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00166-A-002-01
Figure 5. Main Input Gear Quill - Wear Limits (Sheet 1 of 1)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-15A-280A-B
28 OCT 2024 Page 00175-13
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-15A-280A-B
Page 00175-14 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Main Input Gear Quill (412-040-362-101, -103 and -105) - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
India stone
C-464
AR
Remarks
Procedure
1.
If small nicks, burrs, or scratches are visible, dress the splines and the gear with a fine india stone (C-464) (Figure 1).
2.
Repair minor damage to bevel gears by lightly polishing with a fine india stone (C-464) to remove any material that
protrudes above the original ground surface.
Applicable to: SN: 36020-36999 or 37002-37999 or
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-15A-685A-B
28 OCT 2024 Page 00176-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00166-A-002-01
Figure 1. Main Input Gear Quill - Wear Limits (Sheet 1 of 1)
412-A-63-10-00-15A-685A-B
Page 00176-2 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Main Input Gear Quill (412-040-362-101, -103 and -105) - Assembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Power Wrench Kit
Anchor Plate
Socket
T100965
T100968
T101303
1
1
1
Remarks
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Drycleaning solvent
Lockwire
C-304
C-405
AR
AR
Remarks
Procedure
1.
Clean all the parts with drycleaning solvent (C-304) and drain.
NOTE
Refer to the BHT-412-MM for approved lubricants.
2.
Apply all the parts with the same oil used in transmission and drain.
IT IS ESSENTIAL THAT UTMOST PRECISION BE USED WHEN ASSEMBLING THIS QUILL.
3.
Examine the duplex bearings (8, Figure 1) to make sure that the serial number is the same on both bearings. Hold the
bearings back-to-back, measure the width of the outer races, and record as Dimension C (Figure 2).
THE SAME SHIMS (7 AND 10, Figure 1) THAT WERE REMOVED SHALL BE REINSTALLED IF NOT
DAMAGED.
IF SHIM(S) (7 AND/OR 10) ARE DAMAGED, NOTIFY BELL HELICOPTER TEXTRON, CPR
DEPARTMENT AND GIVE DIMENSION C, DIMENSION L, DIMENSION S, DIMENSION T, DIMENSION
X, AND DIMENSION Y (Figure 2 AND Step 4.). SHIM THICKNESS WILL BE CALCULATED AND
APPROPRIATE SHIM WILL BE SENT.
4.
Determine the thickness of shims (7 and 10, Figure 1 for the main input quill as follows:
4.1.
Record the following dimensions.
4.2.
Dim C
-
Measure width of bearing outer races.
Dim X
-
Etched on support case.
Dim Y
-
Etched on support case.
Dim L
-
Etched on shaft.
Dim S
-
Oil collector thickness.
Dim T
-
Etched on bearing retainer plate.
Dim A
-
1.752 inches (44.5 mm)Given: 1.751 to 1.753 inches (44.5 to 44.5 mm)
Determine the thickness of the shim (3) between the bearing and the liner as follows:
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-15A-710A-B
28 OCT 2024 Page 00177-1
BHT-412-CRO
I.
Dim A
1.752 inches (44.5 mm)
Dim Y
+ Dimension Y
= Dimension I
II.
Dim C
Dimension C
Dim X
+ Dimension X
= Dimension II
III.
Dim I (above)
Total dimension of A and Y
Dim II (above)
- Total dimension of C and X
Required thickness for shim (3, Figure 2)
4.3.
= Shim (3) thickness ±0.001 inches (.0 mm)
Determine the thickness of the shim (2) between the case and the bearing retainer as follows:
IV.
Actual shim at III
Total dimension of I and II
Dim C
+ Dimension C
Total dimension of C and III
V.
Dim T
Dimension T
Dim S
+ Dimension S
Dim Y
+ Dimension Y
Pinch required, 0.001 to 0.005 inches (.0
to .1 mm)
+0.0030 inches (.1 mm)
= Total dimension
VI.
Dim IV (above)
Dimension IV
Dim V (above)
- Dimension V
Required thickness for shim (2)
= Total dimension ±0.002 unit- generated text not found
Dim B Measure from lower surface of
gear shaft support case to upper surface
of bevel gear.
Dimension B
Dim L
- Dimension L
Dim B - L should
= 1.751 to 1.753 inches (44.5 to 44.5 mm)
MAKE SURE THAT BEARINGS ARE PROPERLY INSTALLED BACK-TO-BACK. MAKE SURE THAT
SHIMS (7 AND 10) ARE NOT DAMAGED DURING INSTALLATION OF BOLTS. MAKE SURE THAT
BOLTS (4) ARE CORRECTLY SECURED.
5.
Put the shim (7, Figure 1) in the liner of the gear support case (6).
6.
Put the duplex bearings (8) in the back-to-back position over the gear support case (6).
7.
Push the duplex bearings (8) into the gear support case (6).
NOTE
Shims (10) are installed on top of collector (9) on configuration 412-040-362-103 and -105, and under the
collector (9) on configuration 412-040-362-101.
412-A-63-10-00-15A-710A-B
Page 00177-2 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
8.
Put the shim (10) in position and install the collector (9) and the bearing retainer plate (11) with the bolts (4) and the
washers (5) under the bolt heads.
9.
Torque the bolts (4) equally 20 to 25 inch-pounds (2.3 to 2.8 Nm) and attach in pairs with lockwire (C-405).
NOTE
The etched marks placed on the bearings by the bearing manufacturer mark the high point of the race
runout.
10.
Put the gear support case (6) on the shaft of the gear assembly (12). Align the vibro-etched 0 on the ends of the inner
races with the index marks on the shaft.
NOTE
If the gear assembly (12) is being replaced, vibro-etch index mark on a new shaft the same as on the old
shaft.
11.
Push the duplex bearings (8) on the inner races to seat against the shoulder of the shaft on the gear assembly (12).
12.
Install the nut (3).
13.
Put the socket (T101303) and the power wrench kit (T100965) over the nut (3).
14.
Install the anchor plate (T100968) on the shaft.
15.
Torque the nut (3) to the low side of 150 to 200 foot-pounds (203.4 to 271.2 Nm). This is 13.5 to 18 foot-pounds (18.3
to 24.4 Nm)on the torque wrench when using the power wrench kit (T100965).
16.
Remove the tools as necessary to install the lockring (2) on the nut (3). Adjust torque, if necessary, by tightening
within the torque limits until the screw holes line up.
17.
Install the two screws (1) at opposite sides of the shaft and secure each to a hole in the edge of the lockring (2) with
lockwire (C-405).
IT IS IMPERATIVE TO OBTAIN THE PROPER DIMENSION AS FAILURE TO DO SO WILL CAUSE
IMPROPER BACKLASH AND GEAR WEAR PATTERN.
18.
Check the assembly on the surface plate with a vernier height gauge and dial indicator. Measure Dimension B
(Figure 2) at several points approximately 90° apart. Subtract Dimension L, etched on the side of the shaft from
Dimension B. This result is Dimension A and shall be 1.751 to 1.753 inches (44.5 to 44.5 mm). If the dimension is not
obtained, a damaged shim or a shim of incorrect thickness may be the cause. Refer to 412-A-63-10-00-15A-710A-B /
00177 for shim replacement if Dimension A tolerance is not achieved.
19.
Check the bearings for free rotation.
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-15A-710A-B
28 OCT 2024 Page 00177-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00034-A-002-01
Figure 1. Main Input Gear Quill (412-040-362-101, -103 and -105) (Sheet 1 of 1)
412-A-63-10-00-15A-710A-B
Page 00177-4 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00167-A-001-01
Figure 2. Main Input Gear Quill (412-040-362-101, 103 and 105) - Shimming (Sheet 1 of 1)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-15A-710A-B
28 OCT 2024 Page 00177-5
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-15A-710A-B
Page 00177-6 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Main Input Quill (212-040-263-107) - Disassembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Wrench Set
Plate Set
T101588
T101912
1
1
Remarks
Procedure
NOTE
SN: 36020-36999 or 37002-37999 or SN: 38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed:
Refer to 412-A-63-10-00-18A-530A-B / 00188.
1.
Remove the retaining ring (27, Figure 1) and the plate (26).
2.
Remove and discard the packing (25).
3.
Remove the lock spring (24).
4.
Install the wrench set (T101588) on the quill, as shown in Figure 2.
5.
Secure a 3/4 (0.750)-inch (19.05-mm) square bar vertically in a vise and put the quill on the bar with the pinion
engaged on the bar.
6.
Loosen the nut (23, Figure 1).
7.
Remove the wrench set (T101588) and the nut (23).
8.
Remove the curvic coupling adapter (22) from the pinion (1).
9.
Remove the six screws (11) and the six washers (10) from the cap assembly (9).
10.
Remove the cap assembly (9) from the sleeve (2). Discard the shim (4).
11.
Install the plate set (T101912) (1, Figure 3) on the pinion (1,Figure 1) between the gear and the sleeve (2) .
12.
Support the bearing inner race and press the pinion (1) out of the triplex bearings (5).
RETAIN BEARINGS AS A MATCHED SET.
13.
Support the sleeve (2) and press the triplex bearings (5) out of the sleeve by pressing on the outer race. Keep
the bearings together as a matched set.
14.
Remove the packing (3) from the sleeve (2). Discard the packing.
15.
Remove the cap (6) with the union (7) and packing (8) from the cap assembly (9). Discard the packing.
16.
Cut and remove the lockwire.
17.
Remove the plug (13) with the packing (14) from the cap assembly (9). Discard the packing.
18.
Remove the retaining ring (21).
19.
Remove the seal retainer (20) from the cap assembly (9).
20.
Remove the packings (18 and 19) from the seal retainer (20). Discard the packings.
Applicable to: ALL
412-A-63-10-00-16A-530A-B
ECCN EAR99
28 OCT 2024 Page 00178-1
BHT-412-CRO
MAGNETIC SEAL IS MADE UP OF TWO PARTS, THE MAGNETIC RING AND THE CARBON RING.
KEEP THEM TOGETHER AS A MATCHED SET.
DO NOT HANDLE THE PARTS WITH BARE HANDS.
21.
Remove the carbon ring (16) and the magnetic ring (17), as a unit, from the cap assembly (9).
22.
Remove and discard the packing (15).
412-A-63-10-00-16A-530A-B
Applicable to: ALL
Page 00178-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00048-A-001-01
Figure 1. Main Input Quill (212-040-263-107) (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-16A-530A-B
ECCN EAR99
28 OCT 2024 Page 00178-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00168-A-001-01
Figure 2. Wrench Set (T101588) - Application (Sheet 1 of 1)
412-A-63-10-00-16A-530A-B
Applicable to: ALL
Page 00178-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00169-A-001-01
Figure 3. Plate Set (T101912) - Application (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-16A-530A-B
ECCN EAR99
28 OCT 2024 Page 00178-5
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-16A-530A-B
Applicable to: ALL
Page 00178-6 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Main Input Quill (212-040-263-107) - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Corrosion preventive compound
Drycleaning solvent
Solvent
Clean cloth
C-105
C-304
C-334
C-516
AR
AR
AR
AR
Remarks
Procedure
NOTE
SN: 36020-36999 or 37002-37999 or SN: 38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed:
Refer to 412-A-63-10-00-18A-258A-B / 00189.
1.
Clean all the quill parts with drycleaning solvent (C-304). Use a soft bristle brush to dislodge deposits. All parts
except bearings may be cleaned with solvent (C-334) by vapor degreasing.
DO NOT ALLOW BEARINGS TO SPIN WHILE DRYING.
2.
Dry the parts with a clean cloth (C-516) or dry filtered compressed air.
DO NOT HANDLE UNOILED BEARINGS WITH BARE HANDS.
NOTE
Parts treated per the following step may be left covered in indoor storage for approximately 150 hours
without being affected by corrosion.
3.
Coat the bearings with corrosion preventive compound (C-105) immediately after cleaning (BHT-ALL-SPM, Standard
Practices Manual).
Applicable to: ALL
412-A-63-10-00-16A-258A-B
ECCN EAR99
28 OCT 2024 Page 00179-1
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-16A-258A-B
Applicable to: ALL
Page 00179-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Main Input Quill (212-040-263-107) - Inspection
Procedure
NOTE
SN: 36020-36999 or 37002-37999 or SN: 38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed:
Refer to 412-A-63-10-00-18A-280A-B / 00190.
NOTE
Wear limits are provided to show required fit between mating parts. It is not intended that all dimensions
be checked as a prescribed overhaul procedure, however, parts that show evidence of wear or physical
damage must be checked dimensionally.
1.
Inspect the pinion (1, Figure 1) in accordance with Figure 2.
2.
Inspect the sleeve (2, Figure 1) in accordance with Figure 3.
3.
Inspect the triplex bearing (5, Figure 1) for spalling, scoring, pitting, brinelling, corrosion damage, cracked or broken
retainers, and roughness when rotated. Any defect is cause for rejection.
4.
Inspect the cap assembly (9) in accordance with Figure 4.
5.
Inspect the seal retainer (20, Figure 1) in accordance with Figure 5.
6.
Inspect the curvic coupling adapter (22, Figure 1) in accordance with Figure 6.
7.
Inspect the retaining rings (21 and 27, Figure 1) and the Iock spring (24) for obvious defects and deformation.
8.
Inspect the nut (23) for thread damage and obvious defects.
9.
Inspect the plate (26) for corrosion damage and nicks or burrs in the seal groove, which could cause leakage.
THE SEAL INSPECTION PROCEDURE MUST BE ACCOMPLISHED UNDER CLEAN CONDITIONS.
WEAR WHITE COTTON GLOVES WHILE HANDLING SEAL. DO NOT SLIDE MAGNETIC SEAL
ON MAGNETIC RING. DO NOT ALLOW CARBON SEALING SURFACE OR SEALING RING
ON MAGNETIC RING TO CONTACT ANY OTHER OBJECT. DO NOT ALLOW ANY FOREIGN
PARTICLES TO CONTACT SEAL.
NOTE
The magnetic seal is made up of two parts, the magnetic ring (17) and the carbon ring (16), which is
bonded to the seal case.
10.
Inspect the magnetic seal as follows:
10.1.
Measure the gap between the magnetic ring and seal case with a clean, non-metallic feeler gauge (Figure 7, Figure 8,
and Figure 9, as applicable).
10.2.
Separate the magnetic ring (17, Figure 1) from the carbon ring (16) by carefully pulling directly away from each other.
10.3.
Inspect the magnetic ring (17) with a high intensity light for scratches, nicks, and cracks. A cracked ring is
nonrepairable and must be replaced.
10.4.
Inspect the back face and the inside diameter surface conditions of the magnetic ring (17) as follows:
10.4.1.
Porosity holes and voids under 0.020 inch (0.51 mm) in diameter are permitted if less than 0.020 inch (0.51 mm)
deep. Zones of porosity shall not extend more than 1/4 of the way across any surface and shall not extend to
within 0.070 inch (1.78 mm) of any edge.
10.4.2.
Edge chips on the inside diameter and the outside diameter of the back face are permitted if they are less than 0.0625
inch (1.588 mm) long and 0.020 inch (0.51 mm) wide.
10.4.3.
No cracks are permitted.
10.5.
Inspect the outside diameter surface of the magnetic ring (17) as follows:
Applicable to: ALL
412-A-63-10-00-16A-280A-B
ECCN EAR99
28 OCT 2024 Page 00180-1
BHT-412-CRO
10.5.1.
Zones of porosity shall not extend more than 1/4 of the way across any surface and shall not extend to within
0.070 inch (1.78 mm) of any edge.
10.5.2.
Porosity holes are permitted if less than 0.020 inch (0.51 mm) in diameter and less than 0.020 inch (0.51 mm) deep.
10.5.3.
Edge chips are permitted if less than 0.0312 inch (0.793 mm) long and 0.0156 inch (0.396 mm) wide.
10.5.4.
No cracks are permitted.
10.6.
Inspect the sealing face of the magnetic ring (17) as follows:
10.6.1.
The sealing ring is defined as the ring which coincides with the mating carbon sealing surface plus an additional 0.020
inch (0.51 mm) per side allowance. Chips, nicks, and scratches are not allowed on the sealing ring.
10.6.2.
The sealing ring shall be free of porosity holes and pits unless they are within the limits per Figure 7 and Figure 8, as
applicable. Pits and porosity holes must be clean and free of foreign matter. No two pits and/or porosity holes may
be aligned radially across the sealing ring.
10.6.3.
Porosity holes outside the sealing ring are permitted if less than 0.020 inch (0.51 mm) in diameter and less than
0.016 inch (0.41 mm) deep. Zones of porosity shall not extend more than 1/4 of the way across any surface and shall
not extend within 0.070 inch (1.78 mm) of any edge.
10.6.4.
Scratches outside the sealing ring are permitted.
10.6.5.
Chipping on the inside diameter and the outside diameter edges is permitted provided it is outside the sealing ring
and is less than 0.0625 inch (1.588 mm) long and 0.020 inch (0.51 mm) wide.
10.7.
Inspect the seal case and the carbon ring assembly under a high intensity light. Minor scratches and nicks are
permitted on the seal case. The sealing surface of the carbon must show no visible scratches or pits when viewed
under a high intensity light. Damage on the edges of the carbon sealing surface is allowable if no two damaged areas
are aligned with one another in the radial direction and if the number and size of the damaged areas are within the
carbon seal edge damage limits shown in Figure 7 and Figure 8, as applicable.
10.8.
Inspect the packing groove and remove any foreign particles. The groove shall not have any burrs that might
damage the packing.
DO NOT SLIDE SEAL MATING SURFACES AGAINST EACH OTHER AT ANY TIME. DO NOT TOUCH
EITHER SEALING SURFACE WITH ANY FOREIGN OBJECT.
10.9.
Assemble the seal by lining up the two seal halves to their final assembled position and carefully allow the two
halves to pull together into their assembled position.
11.
Inspect the following parts by magnetic particle inspection (Code M) or fluorescent penetrant inspection (Code F), as
applicable. Demagnetize parts after magnetic particle inspection. Refer to Table 2 and the BHT-ALL-SPM, Standard
Practices Manual for the procedure.
Figure 1INDEX NUMBER
NOMENCLATURE
CODE
1
Pinion
M
2
Sleeve
M
9
Cap Assembly
F
20
Seal retainer
F
22
Curvic Coupling Adapter
M
23
Nut
M
Table 2. Magnetic Particle Inspection
PART NUMBER
NOMENCLATURE
ITEM AND FIGURE
SET UP AND MAGNETIZATION CURRENT REQUIREMENTS
MAIN INPUT QUILL (212-040-263-101 AND -107)
204-040-184-001
Nut
412-A-63-10-00-16A-280A-B
Applicable to: ALL
Page 00180-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Table 2. Magnetic Particle Inspection (continued)
23, Figure 1
SET UP:
Place part over a 1.5-inch diameter central conductor.
Current for primary diameters, magnetize at 1990 amps.
Omit coil shot.
204-040-700-101
Pinion
1, Figure 1
SET UP:
Place part over a 0.7-inch diameter central conductor.
Current for primary diameters, magnetize at 4310 amps.
Optional current for secondary diameters, magnetize at 2270 amps.
CENTRAL CONDUCTOR MAY GET HOT.
Omit coil shot.
212-040-190-001
Curvic Coupling Adapter
22, Figure 1
SET UP:
Place part over a 2-inch diameter central conductor.
Current for primary diameters, magnetize at 4180 amps.
Optional current for secondary diameters, magnetize at 1270 amps.
SET UP: 5 TURN COIL SHOT:
Disc-shaped portion of part: Place part in bottom of coil.
Magnetize at 3000 amps.
Rotate part 1/4 turn and repeat.
214-040-097-003
Sleeve
2, Figure 1
SET UP:
Place part over a 2-inch diameter central conductor.
Current for primary diameters, magnetize at 3460 amps.
Optional current for secondary diameters, magnetize at 1960 amps.
Large I.D. of part: Magnetize at four approximately equally spaced radial locations on central conductor.
SET UP: 5 TURN COIL SHOT:
Disc-shaped portion of part: Place part in bottom of coil.
Magnetize at 3000 amps.
NOTES:
1. Magnetization currents provided are applicable to magnetic particle inspection apparatus using Direct Current (DC) . If an
Alternating Current (AC) apparatus is used, adjust the current as follows: AC= 0.667 x DC.
Applicable to: ALL
412-A-63-10-00-16A-280A-B
ECCN EAR99
28 OCT 2024 Page 00180-3
BHT-412-CRO
Table 2. Magnetic Particle Inspection (continued)
2. Ferrous parts requiring magnetic particle inspection that are not addressed in the attached material, are to be inspected in
accordance with the general procedures outlined in ASTM E1444 standard practices (BHT-ALL-SPM, Chapter 6, Standard
Practices Manual).
3. Part numbers listed apply to all successive dash numbers for that component unless otherwise specified.
412-A-63-10-00-16A-280A-B
Applicable to: ALL
Page 00180-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00048-A-001-01
Figure 1. Main Input Quill (212-040-263-107) (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-16A-280A-B
ECCN EAR99
28 OCT 2024 Page 00180-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00170-A-001-01
Figure 2. Main Input Drive Quill Pinion - Damage Limits (Sheet 1 of 1)
412-A-63-10-00-16A-280A-B
Applicable to: ALL
Page 00180-6 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00171-A-001-01
Figure 3. Main Input Drive Quill Sleeve - Damage Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-16A-280A-B
ECCN EAR99
28 OCT 2024 Page 00180-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00172-A-001-01
Figure 4. Main Input Quill Cap Assembly - Damage Limits (Sheet 1 of 1)
412-A-63-10-00-16A-280A-B
Applicable to: ALL
Page 00180-8 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00173-A-001-01
Figure 5. Main Input Quill Seal Retainer - Damage Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-16A-280A-B
ECCN EAR99
28 OCT 2024 Page 00180-9
BHT-412-CRO
ICN-412-A-631000-B-97499-00174-A-001-01
Figure 6. Main Input Quill Curvic Coupling Adapter - Damage Limits (Sheet 1 of 1)
412-A-63-10-00-16A-280A-B
Applicable to: ALL
Page 00180-10 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00175-A-001-01
Figure 7. Magnetic Seal - Damage Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-16A-280A-B
ECCN EAR99
28 OCT 2024 Page 00180-11
BHT-412-CRO
ICN-412-A-631000-B-97499-00176-A-001-01
Figure 8. Seal Case and Carbon Sealing Element (412-040-111-105) - Damage Limits (Sheet 1 of 3)
412-A-63-10-00-16A-280A-B
Applicable to: ALL
Page 00180-12 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00177-A-001-01
Figure 8. Seal Case and Carbon Sealing Element (412-040-111-105) - Damage Limits (Sheet 2 of 3)
Applicable to: ALL
412-A-63-10-00-16A-280A-B
ECCN EAR99
28 OCT 2024 Page 00180-13
BHT-412-CRO
ICN-412-A-631000-B-97499-00178-A-001-01
Figure 8. Seal Case and Carbon Sealing Element (412-040-111-105) - Damage Limits (Sheet 3 of 3)
412-A-63-10-00-16A-280A-B
Applicable to: ALL
Page 00180-14 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00179-A-001-01
Figure 9. Magnetic Seal (412-040-111-105) - Damage Limits (Sheet 1 of 2)
Applicable to: ALL
412-A-63-10-00-16A-280A-B
ECCN EAR99
28 OCT 2024 Page 00180-15
BHT-412-CRO
ICN-412-A-631000-B-97499-00180-A-001-01
Figure 9. Magnetic Seal (412-040-111-105) - Damage Limits (Sheet 2 of 2)
412-A-63-10-00-16A-280A-B
Applicable to: ALL
Page 00180-16 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Main Input Quill (212-040-263-107) - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Zinc chromate primer
Abrasive cloth or paper
Abrasive pad
India stone
C-201
C-406
C-407
C-464
AR
AR
AR
AR
Remarks
Procedure
NOTE
SN: 36020-36999 or 37002-37999 or SN: 38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed:
Refer to 412-A-63-10-00-18A-685A-B / 00191.
1.
Polish out minor dents and nicks on the sleeve (2, Figure 1) flange top surface with a fine india stone (C-464). Blend
the repaired area into the flat surface with a minimum radius of 0.12 inch (3.0 mm). The finished repair must be 32
Roughness Height Rating (RHR) or better. The maximum depth, after repair, must not exceed 0.030 inch (0.76 mm).
2.
Polish out minor dents, nicks, and scratches on the exterior surfaces of the cap assembly (9) with abrasive cloth
or paper (C-406). Replace a loose or deformed alignment pin(12). Coat the pin with zinc chromate primer (C-201)
immediately prior to installation.
3.
Polish out minor nicks, dents, and scratches on the curvic coupling adapter (22) with a fine india stone (C-464).
4.
Polish out minor nicks, dents, and scratches on the seal retainer (20) with abrasive cloth or paper (C-406).
5.
Polish out minor nicks, dents, and scratches on the plate (26) with abrasive cloth or paper (C-406).
NOTE
If you return the part to Bell Helicopter Textron (BHT) , refer to General Information Letter (IL) GEN-04-98
for applicable shipping information and to obtain a Return Material Authorization (RMA) number.
6.
Repair of the magnetic seal by the user is not permitted. If there is evidence of damage, return the part to the
manufacturer, one of its authorized service centers, or Bell for evaluation and possible repair.
7.
Repair the pinion (1) as follows:
7.1.
Repair minor nicks, burrs, or scratches on non-contact surfaces of the gears of the splines with a fine abrasive
pad (C-407).
7.2.
Repair nicks, dents, and scratches on the spline teeth by smoothing out with a fine abrasive pad (C-407). Do
not exceed the limits defined in Figure 2.
DO NOT STRIP GEAR TEETH OR SPLINES DURING COPPER STRIPPING OPERATION. MASK GEAR
TEETH AND SPLINES TO PREVENT ACCUMULATION OF COPPER DEPOSITS DURING COPPER
PLATING OPERATIONS.
7.3.
Strip and replace the copper plating as follows (BHT-ALL-SPM, Standard Practices Manual):
7.3.1.
Strip the copper plating on the triplex bearing journal (Figure 3).
7.3.2.
The outside diameter of the triplex bearing journal should be 3.1501 to 3.1503 inches (80.013 to 80.017 mm) before
the copper plating and 3.1511 to 3.1515 inches (80.038 to 80.048 mm) after the copper plating. The copper plating
shall be 0.0003 to 0.0007 inch (0.008 to 0.017 mm) thick after plating (Figure 3).
8.
Refinish parts (except pinion) after repair in accordance with Figure 4.
Applicable to: ALL
412-A-63-10-00-16A-685A-B
ECCN EAR99
28 OCT 2024 Page 00181-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00048-A-001-01
Figure 1. Main Input Quill (212-040-263-107) (Sheet 1 of 1)
412-A-63-10-00-16A-685A-B
Applicable to: ALL
Page 00181-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00170-A-001-01
Figure 2. Main Input Drive Quill Pinion - Damage Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-16A-685A-B
ECCN EAR99
28 OCT 2024 Page 00181-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00182-A-001-01
Figure 3. Main Input Quill Pinion - Copper Plating Area (Sheet 1 of 1)
412-A-63-10-00-16A-685A-B
Applicable to: ALL
Page 00181-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00183-A-001-01
Figure 4. Main Input Quill Processing Requirements (Sheet 1 of 2)
Applicable to: ALL
412-A-63-10-00-16A-685A-B
ECCN EAR99
28 OCT 2024 Page 00181-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00184-A-001-01
Figure 4. Main Input Quill Processing Requirements (Sheet 2 of 2)
412-A-63-10-00-16A-685A-B
Applicable to: ALL
Page 00181-6 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Main Input Quill (212-040-263-107) - Assembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Wrench Set
T101588
1
Remarks
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Assembly fluid
India stone
Lockwire
C-024
C-464
C-405
AR
AR
AR
Remarks
Procedure
NOTE
SN: 36020-36999 or 37002-37999 or SN: 38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed:
Refer to 412-A-63-10-00-18A-710A-B / 00192.
1.
Make sure that all the parts have been cleaned (412-A-63-10-00-16A-258A-B / 00179).
2.
Coat the triplex bearings (5, Figure 1), sleeve (2), and pinion (1) with approved transmission lubricating oil and
allow parts to drain.
3.
Assemble the triplex bearing (5) and the sleeve (2) as follows:
DO NOT PRESS ON THE BEARING INNER RACES DURING INSTALLATION OR DAMAGE TO THE
BEARING WILL OCCUR.
NOTE
A dull burr mark approximately 0.125 inch (3.18 mm) in diameter is placed on an end face of each bearing
inner race member by the bearing manufacturer to mark the high point of the race runout. Bearings shall
be installed with the inner races of the three member bearings positioned with the dull burr marks aligned.
Before installing the bearings, with a non-permanent marker, mark an axial line across the inner diameter
of each member bearing aligned with the dull burr mark. The marks shall be used to align the bearing
inner races when the pinion (1) is installed.
3.1.
Align the V-marks on the outer races of the triplex bearing (5). Support the sleeve (2) and press the bearings into the
sleeve with the apex of the V-mark pointing as shown in Figure 1.
NOTE
Make sure the bearing outer races are fully seated against the shoulder in the sleeve.
3.2.
With the sleeve (2) and the triplex bearing (5) resting on the inboard end of the sleeve, put the cap assembly (9) in
position with the cap lip resting on the face of the triplex bearing outer race. Apply 30 to 50 pounds (133.44 to 222.4
N) axial force uniformly to the end of the cap until fully seated against the outer race of the triplex bearing.
3.3.
With a feeler gauge, measure the gap between the cap assembly (9) and the sleeve (2) at a minimum of three
approximately equally spaced locations.
3.4.
Peel the shim (4) 0.001 to 0.004 inch (0.03 to 0.10 mm) less than the gap measured in Step 3.3.. This will provide a
0.001 to 0.004 inch (0.03 to 0.10 mm) pinch on the outer race of the triplex bearing.
3.5.
Remove the cap assembly (9) from the sleeve (2).
4.
Install the pinion (1) in the triplex bearing (5) as follows:
Applicable to: ALL
412-A-63-10-00-16A-710A-B
ECCN EAR99
28 OCT 2024 Page 00182-1
BHT-412-CRO
NOTE
Index marks are etched on the inner races of inboard and outboard members of the triplex bearing (5)
and on the pinion (1) to provide a means of detecting inner race slippage on the pinion. Quill assemblies
are inspected for bearing slippage following bench acceptance testing during original manufacture and
during 3100 hour special inspections of the helicopter.
4.1.
If the pinion (1) is being replaced and thereplacement part has index marks applied, proceed to Step 4.2.. If the
part has not been index marked, proceed as follows:
4.1.1.
With a vibrating stylus, etch a line across the pinion outer diameter, as shown in Figure 2.
4.1.2.
Remove all raised material at the edges of the etched line with a fine india stone (C-464).
4.2.
If the bearing (5) is being replaced and replacement the part has index markings, proceed directly to Step 4.3.. If the
part has no etch index marks on the faces of the end bearing inner races, proceed as follows:
4.2.1.
Mask the inboard member bearing and sleeve (2) with a suitable tape so that only the inboard face and bore of the
bearing are exposed (Figure 2).
DO NOT DAMAGE BEARING CAGE WHILE PERFORMING THE FOLLOWING Step 4.2.2.
Step 4.2.3..
AND
NOTE
The location of the etched line relative to the bearing dull burr marks is not important.
4.2.2.
With a vibrating stylus, etch a short radial line on the face of the bearing inner race, as shown in Figure 2.
4.2.3.
With a fine india stone (C-464), remove all raised material at the edges of the etched line flush with the surrounding
surface.
REMOVE ALL DEBRIS FROM MASKING MATERIAL AND SURROUNDING AREAS BEFORE
REMOVING MASKING MATERIAL. DEBRIS CAN DAMAGE BEARING.
4.2.4.
Remove all masking material from the triplex bearing (5, Figure 1) and the sleeve (2).
DO NOT EXCEED THE MAXIMUM ALLOWABLE TEMPERATURE WHEN YOU HEAT A PART OR
DAMAGE TO THE PART MAY OCCUR.
4.3.
Heat the sleeve (2) with the triplex bearing (5) uniformly to 230 to 250°F (110 to 121°C).
4.4.
Wipe the bore of the triplex bearing (5) and the mating journal of the pinion (1) free of oil.
4.5.
Put the sleeve (2) with the triplex bearing (5) in a suitable press so that the assembly is uniformly supported on the
inner race of the outboard bearing.
NOTE
The replacement pinion (1) or triplex bearing (5) may have etched index marks only at the inboard ends
at this point.
4.6.
Align the inner races of the three member bearings of the triplex bearing (5) so that the axial lines marked in Step 3.
are in alignment.
DO NOT MISALIGN BEARING BURR MARKS IN AN EFFORT TO IMPROVE ALIGNMENT OF
INBOARD AND OUTBOARD INDEX MARKS. EXACT ALIGNMENT OF INDEX MARKS IS NOT
NECESSARY. ANY MISALIGNMENT AFTER ASSEMBLY WILL BE RECORDED IN Step 4.11. AND
Step 4.12.
412-A-63-10-00-16A-710A-B
Applicable to: ALL
Page 00182-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
4.7.
Put the pinion (1) in position so that the index mark on the pinion shoulder is aligned with the index mark on the
face of the bearing inner race as closely as possible. For previously used pinions and bearings it is also necessary
to align the index mark on the pinion spline with the corresponding mark on the face of the outboard member
bearing as closely as possible.
4.8.
Press the pinion through the bearing until pinion shoulder is firmly seated against the inner race of the inboard bearing.
4.9.
Apply and hold 18 to 20 tons (160,136 to 177,928 N) of seating pressure on the pinion until the assembly has
cooled to room temperature.
4.10.
If an index mark exists on the outboard (splined) end of the pinion (1) or the outboard face of the bearing inner race,
proceed to Step 4.11.. If an index mark does not exist, proceed as follows:
4.10.1.
With suitable tape, mask the outboard member of the triplex bearing (5) and the sleeve (2) so that only the face of the
bearing inner race and the splined end of the pinion are exposed.
DO NOT DAMAGE BEARING CAGE WHILE PERFORMING FOLLOWING Step 4.10.2. THROUGH
Step 4.10.4..
4.10.2.
If the triplex bearing (5) is not marked but the pinion (1) has an etched mark, mark the face of the bearing inner race
with a short radial line aligned with the pinion mark, with a vibrating stylus. Mark a line, as shown in Figure 2,
for inboard end marking.
4.10.3.
If the triplex bearing (5, Figure 1) has an index mark but the pinion (1) is not marked, mark an approximately 0.19 inch
(4.8 mm) long axial line on the pinion diameter, outboard of the pinion journal. With a vibrating stylus, etch mark
adjacent to the bearing aligned with the index mark on the bearing.
4.10.4.
If both pinion (1) and triplex bearing (5) are not marked, etch index marks on both parts in accordance with the
previous Step 4.10.2. and Step 4.10.3..
REMOVE ALL DEBRIS FROM MASKING MATERIAL AND FROM SURROUNDING AREAS BEFORE
REMOVING MASKING MATERIAL. DEBRIS CAN DAMAGE BEARING.
4.11.
Measure and record in the quill maintenance record the amount and direction that the outboard bearing index mark
is offset from the index mark on the pinion shank. Make an evaluation while viewing the bearing from the splined
end of the pinion.
4.12.
Measure and record in the quill maintenance record the amount and direction that the inboard bearing index mark is
offset from the index mark on the pinion outer diameter at the bearing shoulder. Make an evaluation while viewing the
bearing from the gear head end of the pinion.
IF BEARINGS ARE REMOVED FROM PINION FOR ANY REASON AFTER INSTALLATION, STRIP
AND REAPPLY COPPER PLATE TO PINION (412-A-63-10-00-16A-685A-B / 00181).
5.
Lubricate the new packing (3) with approved transmission oil and install in the groove of the sleeve (2).
6.
Lubricate the new packings (18 and 19) and the mating grooves of the seal retainer (20) with assembly fluid (C-024).
7.
Install the packings (18 and 19) on the seal retainer (20).
8.
Align the slot of the seal retainer (20) with the alignment pin (12) in the cap assembly (9) and install the seal retainer
in the cap assembly.
9.
Install the retaining ring (21).
DO NOT TOUCH SEALING FACES OF CARBON RING (16) OR MAGNETIC RING (17) WITH BARE
FINGERS. HANDLE THE SEAL COMPONENTS WITH CLEAN COTTON GLOVES.
Applicable to: ALL
412-A-63-10-00-16A-710A-B
ECCN EAR99
28 OCT 2024 Page 00182-3
BHT-412-CRO
KEEP SEAL IN ORIGINAL PACKAGING UNTIL READY FOR INSTALLATION. WHEN SEAL
PACKAGE IS OPENED, SEPARATE SEAL BY PULLING MAGNETIC RING AND CARBON RING
STRAIGHT AWAY FROM EACH OTHER. SLIDING BETWEEN SEAL HALVES MAY DAMAGE
MATING SURFACES. DO NOT PLACE MAGNETIC RING OR CARBON RING IN AREA WHERE
METAL PARTICLES MAY BE ATTRACTED. INSTALL SEAL BY HAND PRESSING ONLY. PRIOR TO
INSTALLATION OF SEAL, LUBRICATE PACKINGS AND MATING DIAMETERS SPARINGLY WITH
assembly fluid (C-024). DO NOT ALLOW assembly fluid (C-024) TO CONTACT CARBON SEALING
SURFACE.
NOTE
The magnetic seal is made of two parts, the carbon ring (16) and the magnetic ring (17).
10.
Lubricate a new packing (15) and the mating groove of the carbon ring (16) with assembly fluid (C-024) and install
the packing in the carbon ring.
11.
Install the magnetic ring (17) into the seal retainer (20). Make sure the part number on the magnetic ring points to the
flange of the seal retainer and the ring points to the bearing.
12.
Put the curvic coupling adapter (22), flanged end down, on a clean surface and apply a light coating of assembly fluid
(C-024) to the outer diameter at the uppermost end.
13.
Install the cap assembly (9) with the magnetic ring (17), seal retainer (20), new packing (19), and retaining ring
(21) over the curvic coupling adapter (22).
14.
Carefully install the carbon ring (16) with the new packing (15) on the upper end of the curvic coupling adapter (22)
with the carbon seal facing down. Slide the seal down on the adapter so that the upper surface of the ring is 0.30 to
0.35 inch (7.6 to 8.9 mm) from the upper end of the adapter.
NOTE
Allow the previously assembled curvic coupling adapter (22) with the cap assembly (9) and the seal
components to remain on the work bench with the flanged end down through the assembly (Step 18.).
This will prevent the carbon ring (16) from sliding off the adapter during the assembly of the quill.
15.
Place a new shim (4) that was sized in Step 3.4. on the flange face of the cap assembly (9).
16.
Carefully lower the pinion (1) with the sleeve (2) and the triplex bearing (5) onto the curvic coupling adapter (22) while
engaging the pinion and adapter splines.
17.
Align the screw holes of the cap assembly (9) with the threaded holes in the flange of the sleeve (2) and install the
washers (10) and the screws (11). Do not tighten the screws at this time.
18.
Uniformly force the cap assembly (9) against the triplex bearing (5) outer race by hand and while holding in position,
use a feeler gauge to check for 0.001 to 0.004 inch (0.03 to 0.10 mm) clearance between the cap assembly and
the shims (4).
DO NOT ALLOW CURVIC COUPLING ADAPTER (22) TO SLIP OUTWARD ON PINION (1) WHEN
QUILL ASSEMBLY IS TURNED OVER. SLIPPAGE OF ADAPTER MAY SEPARATE MAGNETIC
RING (17) FROM CARBON RING (16). SHOULD ADAPTER SLIP OUTWARD, REMOVE ADAPTER,
SEAL, CAP SUBASSEMBLY FROM PINION, SLEEVE, BEARING SUBASSEMBLY AND PLACE
THE ADAPTER, SEAL, CAP SUBASSEMBLY ON WORK BENCH WITH ADAPTER FLANGED END
DOWN, THEN REPEAT Step 14. THROUGH Step 18..
NOTE
Should removal of the adapter, seal, or cap subassembly from the pinion be required, the carbon ring
(16) must be returned to the starting position of Step 14. before Step 15. through Step 18. are repeated.
19.
Hold the curvic coupling adapter (22) against the triplex bearing (5) in the sleeve (2) and turn the quill over so that the
inboard end of the pinion (1) is down. Provide a suitable support for the assembly to stabilize it in this position.
412-A-63-10-00-16A-710A-B
Applicable to: ALL
Page 00182-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
20.
Tighten the screws (11) and secure with lockwire (C-405) to anchor the holes in the cap assembly (9). Make sure
the screws do not protrude beyond the mounting face of the sleeve (2). If the screws protrude, a thin steel washer
may be added under the head of the screw.
21.
Install the nut (23) on the pinion (1) and hand tighten the nut.
22.
Install the wrench set (T101588) onto the curvic coupling adapter (22) with the splined extension outboard.
23.
Install the 3/4 (0.750)-inch (19.05-mm) drive, 12.0 inches (305 mm) extension bar (L-122) into the wrench set
(T101588).
24.
Make sure the square drive of the extension bar (L-122) engages with the square drive of the pinion (1).
QUILL ASSEMBLY MUST BE WELL PADDED AND SUITABLY SUPPORTED ON WORK BENCH
DURING FOLLOWING TORQUING OPERATIONS TO AVOID DAMAGE TO QUILL.
25.
Install the torque wrench with the 3/4 (0.750)-inch (19.05-mm) square drive into the 3/4 (0.750)-inch (19.05-mm)
square drive of the wrench set (T101588) and torque the nut (23) 350 to 400 foot-pounds (474 to 542 Nm).
26.
Remove the extension bar (L-122) and the wrench set (T101588).
27.
Install the lock spring (24). Make sure the lock spring is fully seated in the groove in the splines of the pinion (1).
28.
Lubricate the new packing (25) and the mating surface of the plate (26) with approved transmission oil.
29.
Install the packing (25) on the plate (26).
30.
Install the plate (26) and secure with the retaining ring (27).
31.
Lubricate a new packing (8) with approved transmission oil and install on the union (7).
32.
Install the union (7) in the cap assembly (9). Install the cap (6) on the union.
33.
Lubricate a new packing (14) with approved transmission oil and install the packing on the plug (13). Install the plug
in the cap assembly (9).
34.
Tighten the plug (13) and secure with lockwire (C-405) to the anchor hole of the cap assembly (9).
Applicable to: ALL
412-A-63-10-00-16A-710A-B
ECCN EAR99
28 OCT 2024 Page 00182-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00048-A-001-01
Figure 1. Main Input Quill (212-040-263-107) (Sheet 1 of 1)
412-A-63-10-00-16A-710A-B
Applicable to: ALL
Page 00182-6 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00185-A-001-01
Figure 2. Pinion and Triplex Bearing Etching (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-16A-710A-B
ECCN EAR99
28 OCT 2024 Page 00182-7
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-16A-710A-B
Applicable to: ALL
Page 00182-8 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Main Input Quill (212-040-263-101) - Disassembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Wrench Set
Plate Set
T101588
T101912
1
1
Remarks
Procedure
1.
Remove the retaining ring (25, Figure 1) and the plate (24).
2.
Remove and discard the packing (23).
3.
Remove the lock spring (22).
4.
Install the wrench set (T101588) on the quill. as shown in Figure 2.
5.
Secure a 3/4 (0.750)-inch (19.05-mm) square bar vertically in a vise and put the quill on the bar with the pinion
engaged on the bar.
6.
Loosen the nut (21, Figure 1).
NOTE
The wear sleeve (19) is bonded to the adapter (20). Do not attempt to remove the wear sleeve unless the
wear or damage limits are exceeded. Refer to 412-A-63-10-00-17A-280A-B / 00185 for inspection and
412-A-63-10-00-17A-685A-B / 00186 for repair.
7.
Remove the wrench set (T101588) and the nut (21).
8.
Remove the adapter (20) from the pinion (1).
9.
Remove the six screws (11) and six washers (10) from the cap assembly (9).
10.
Remove the cap assembly (9) from the sleeve (2). Discard the shim (4).
11.
Install the plate set (T101912) (1, Figure 3) on the pinion (1, Figure 1) between the gear and the sleeve (2).
12.
Support the bearing inner race and press the pinion (1) out of the triplex bearings (5).
RETAIN BEARINGS AS A MATCHED SET.
13.
Support the sleeve (2) and press the triplex bearings (5) out of the sleeve by pressing on the outer race. Keep
the bearings together as a matched set.
14.
Remove the packing (3) from the sleeve (2). Discard the packing.
15.
Remove the dust cap (6) with the union (7) and the packing (8) from the cap assembly (9). Discard the packing.
16.
Cut and remove the lockwire.
17.
Remove the plug (14) with the packing (15) from the cap assembly (9). Discard the packing.
18.
Remove the retaining ring (18) and the sleeve (17).
19.
Remove the packing (16) from the sleeve (17). Discard the packing.
20.
Remove the seal (12) from the cap assembly (9). Discard the seal.
21.
Remove the pin (13) when damaged.
Applicable to: ALL
412-A-63-10-00-17A-530A-B
ECCN EAR99
28 OCT 2024 Page 00183-1
BHT-412-CRO
ICN-412-A-631000-B-97499-02802-A-002-01
Figure 1. Main Input Quill Assembly (212-040-263-101) (Sheet 1 of 1)
412-A-63-10-00-17A-530A-B
Applicable to: ALL
Page 00183-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00168-A-001-01
Figure 2. Wrench Set (T101588) - Application (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-17A-530A-B
ECCN EAR99
28 OCT 2024 Page 00183-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00169-A-001-01
Figure 3. Plate Set (T101912) - Application (Sheet 1 of 1)
412-A-63-10-00-17A-530A-B
Applicable to: ALL
Page 00183-4 28 OCT 2024
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BHT-412-CRO
Main Input Quill (212-040-263-101) - Cleaning
Procedure
1.
Clean the main input quill components with the materials and the procedures provided in 412-A-63-10-00-16A-258A-B
/ 00179.
Applicable to: ALL
412-A-63-10-00-17A-258A-B
ECCN EAR99
31 MAY 2023 Page 00184-1
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-17A-258A-B
Applicable to: ALL
Page 00184-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Main Input Quill (212-040-263-101) - Inspection
Procedure
1.
Inspect the main input quill components with the procedures and the limits provided in the 412-A-63-10-00-16A-280A-B
/ 00180, except for the following:
1.1.
Inspect the wear sleeve (19, Figure 1) on the adapter (20) for roughness or seal grooving using a probe with a
point of approximately 0.020 inch (0.51 mm) radius.
1.2.
Inspect the sleeve (17) for obvious damage and excessive wear. Pay particular attention to the packing groove.
2.
Inspect the sleeve (17) by fluorescent penetrant method (BHT-ALL-SPM, Standard Practices Manual).
Applicable to: ALL
412-A-63-10-00-17A-280A-B
ECCN EAR99
28 OCT 2024 Page 00185-1
BHT-412-CRO
ICN-412-A-631000-B-97499-02802-A-002-01
Figure 1. Main Input Quill Assembly (212-040-263-101) (Sheet 1 of 1)
412-A-63-10-00-17A-280A-B
Applicable to: ALL
Page 00185-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Main Input Quill (212-040-263-101) - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Adhesive
Adhesion promoter
C-317
C-327
C-345
C-407
C-436
C-486
C-406
AR
AR
AR
AR
AR
AR
AR
Abrasive pad
Paint remover
Cheesecloth
Abrasive cloth or paper
Remarks
Procedure
1.
Repair the main input quill components with the materials and the procedures provided in 412-A-63-10-00-16A-280A-B
/ 00180, except the parts in the steps that follow:
2.
Replace the wear sleeve (19, Figure 1) if it is worn or rough as follows:
2.1.
Use an end mill or hand-held grinder to cut a groove almost through the old wear sleeve (19). Avoid cutting through
the wear sleeve and damaging the adapter (20). Strike the wear sleeve with a rubber mallet to break the uncut portion
and remove the sleeve from the adapter.
2.2.
Clean the adhesive from the adapter (20) with a plastic scraper and abrasive pad (C-407) or use paint remover
(C-436). Inspect the adapter for damage that may have occurred during the removal of the wear sleeve.
PRECAUTIONS MUST BE TAKEN DURING ACCOMPLISHMENT OF THE FOLLOWING STEPS TO
KEEP WEAR SLEEVE AND ADAPTER CLEAN. WEAR CLEAN WHITE GLOVES WHEN HANDLING
PARTS AND CHANGE GLOVES WHEN THEY BECOME SOILED. COVER WORK BENCH WITH
CLEAN KRAFT PAPER. AVOID CONTACT WITH ALL MOLD RELEASE AGENTS SUCH AS
SILICONE, WAX, OIL, GREASE, ETC. THE WORK AREA WHERE BONDING IS DONE MUST BE
MAINTAINED AT 65° TO 82°F (18° TO 28°C) WITH RELATIVE HUMIDITY BELOW 75%. IT MUST BE
DUST FREE TO THE EXTENT THAT BONDING OPERATIONS ARE NOT AFFECTED.
BONDING STEPS MUST BE ACCOMPLISHED WITHOUT DELAY BETWEEN STEPS. THE MAXIMUM
TIME INTERVAL BETWEEN SANDBLASTING AND THE NEXT STEP IS 4 HOURS.
2.3.
Mask the outer diameter of the new wear sleeve (19). Mask the adapter (20) all over except the surface that
mates with the wear sleeve and the adjacent 0.062-inch (1.57-mm) radius. Sandblast the unmasked surfaces of
these parts with 60 grit garnet at 5 to 10 PSI (34.5 to 69 kPa) and remove the residue. Wrap the parts in clean
Kraft paper after sandblasting.
THE SOLVENT IN PRIMER IS TOXIC. USE PRIMER IN WELL VENTILATED AREA.
2.4.
Stir the primer thoroughly in its container and apply (C-345) to the unmasked portion of the adapter (20) only; this
step is not applicable to the wear sleeve. Scrub primer into the surface of the outer race with abrasive cloth or paper
(C-406). Use additional primer as required to ensure that the adapter is clean.
2.5.
Allow the (C-345) to dry to a white powder. Remove the dry powder with a clean dry cheesecloth (C-486). Wear
clean white gloves while handling parts. If the next step is not to be accomplished immediately, wrap the adapter
(20) with clean Kraft paper.
Applicable to: ALL
412-A-63-10-00-17A-685A-B
ECCN EAR99
28 OCT 2024 Page 00186-1
BHT-412-CRO
THE adhesion promoter (C-327) USED IN FOLLOWING STEP IS HIGHLY VOLATILE. USE IT IN
WELL VENTILATED AREA. KEEP PROMOTER IN NON-ABSORPTIVE CONTAINER AND KEEP LID
TIGHTLY CLOSED WHEN NOT IN USE. EXPOSURE TO ATMOSPHERE WILL CAUSE GRADUAL
DECOMPOSITION, EXCEPT WHEN APPLIED TO PARTS AND ALLOWED TO DRY. SEDIMENT OR
BROWN RESIDUE IN BOTTOM OF CONTAINER INDICATES DECOMPOSITION OF PROMOTER TO
EXTENT THAT IT SHOULD BE DISCARDED. THE PH RANGE OF THE PROMOTER MUST BE 7 TO 8.
2.6.
Apply adhesion promoter (C-327) to the unmasked portion of the wear sleeve (19) and adapter (20) with a brush. Use
a pure (hog bristle) brush with an unpainted handle. Apply only enough adhesion promoter to wet the surfaces. Allow
the promoter to dry for a minimum of 30 minutes at room temperature or for 15 minutes at 150 to 160°F (66 to 71°C).
If the next step is not to be accomplished immediately, wrap the parts with clean Kraft paper.
2.7.
Mix the adhesive (C-317) (33 parts B to 100 parts A). The pot life of mixed adhesive is 30 to 50 minutes. Coat the
inside diameter of the wear sleeve (19) and the mating surface on the adapter with adhesive. Press the wear sleeve
on the adapter with the radiused outside diameter of the wear sleeve positioned at the outer edge of the adapter
(Figure 1, Detail B). Clean off excess adhesive, leaving chamfer between the wear sleeve and the adapter filled with
adhesive. Cure at room temperature for 24 hours. After bonding and prior to the assembly of the quill, make sure that
all traces of adhesive are cleaned from the area of the wear sleeve that contacts the seal (12).
3.
Replace the pin (13) if damaged (Figure 1, Detail A).
412-A-63-10-00-17A-685A-B
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Page 00186-2 28 OCT 2024
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ICN-412-A-631000-B-97499-02802-A-002-01
Figure 1. Main Input Quill Assembly (212-040-263-101) (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-17A-685A-B
ECCN EAR99
28 OCT 2024 Page 00186-3
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-17A-685A-B
Applicable to: ALL
Page 00186-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Main Input Quill (212-040-263-101) - Assembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Wrench Set
T101588
1
Remarks
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Dry film lubricant
Sealant
Lockwire
C-028
C-328
C-405
AR
AR
AR
Remarks
Procedure
1.
Make sure that all the parts have been cleaned (412-A-63-10-00-17A-258A-B / 00184).
DO NOT HANDLE UNOILED PARTS WITH BARE HANDS.
KEEP SEAL IN ORIGINAL PACKAGING UNTIL READY FOR INSTALLATION.
2.
Lubricate the packings and the parts (except the wear sleeve (19, Figure 1) and the seal (12) with the same oil
used in the transmission and allow to drain.
3.
Apply a film of sealant (C-328) to the outer surface of the new seal (12). Press the seal into the sleeve (17) with the
seal lip facing inboard, as shown in Figure 1. Remove the excess sealant.
4.
Install the new packing (16) on the sleeve (17). Align the slot in the sleeve with the pin (13). Install the sleeve in the
cap assembly (9) by hand pressing. Install the retaining ring (18).
5.
Assemble the triplex bearing (5) and the sleeve (2) as follows:
DO NOT PRESS ON THE BEARING INNER RACES DURING THE INSTALLATION OR DAMAGE TO
THE BEARING WILL OCCUR.
NOTE
A dull burr mark approximately 0.125 inch (3.18 mm) in diameter is placed on an end face of each bearing
inner race member by the bearing manufacturer to mark the high point of the race runout. Bearings shall
be installed with the inner races of the three member bearings positioned with the dull burr marks aligned.
Before installing bearings, with a non-permanent marker, mark an axial line across the inner diameter of
each member bearing aligned with the dull burr mark. The marks shall be used to align the bearing inner
races when the pinion (1) is installed.
5.1.
Align the V-marks on the outer races of the triplex bearing (5). Support the sleeve (2) and press the bearings into the
sleeve with the apex of the V-mark pointing as shown in Figure 1.
NOTE
Make sure the bearing outer races are fully seated against the shoulder in the sleeve.
5.2.
With the sleeve (2) and the triplex bearing (5) resting on the inboard end of the sleeve, put the cap assembly (9) in
position with the cap lip resting on the face of the triplex bearing outer race. Apply 30 to 50 pounds (133.44 to 222.4
N) axial force uniformly to the end of the cap until fully seated against the outer race of the triplex bearing.
Applicable to: ALL
412-A-63-10-00-17A-710A-B
ECCN EAR99
28 OCT 2024 Page 00187-1
BHT-412-CRO
5.3.
With a feeler gauge, measure the gap between the cap assembly (9) and the sleeve (2) at a minimum of three
approximately equally spaced locations.
5.4.
Peel the shim (4) 0.001 to 0.004 inch (0.03 to 0.10 mm) less than the gap measured in Step 5.3.. This will provide a
0.001 to 0.004 inch (0.03 to 0.10 mm) pinch on the outer race of the triplex bearing.
5.5.
Remove the cap assembly (9) from the sleeve (2).
6.
Align the inner races of the three bearings so that the non-permanent marker line shows that three dull burr marks
of the bearings are aligned. Put the pinion (1) in position so that the vibro-etched index marks on the pinion shaft
are aligned with the vibro-etched index marks on the bearing inner races.
NOTE
If the bearings or the pinion were replaced, it will be necessary to vibro-etch index marks (lines) on the
new part the same as on the part replaced, so that the bearings may be checked for spinning after the
test run. If the bearings are replaced, be sure that the dull burr marks on the inner races are aligned when
the index marks are vibro-etched on the races.
7.
Install the pinion (1) on the triplex bearing (5) in accordance with 412-A-63-10-00-16A-710A-B / 00182.
8.
Lubricate a new packing (3, Figure 1) with the same oil used in the transmission and install on the sleeve (2).
9.
Put the new shim (4) and the cap assembly (9) on the sleeve (2).
10.
Align the screw holes and install the washers (10) and the screws (11). Do not tighten the screws at this time.
11.
Make sure the screws (11) do not protrude beyond the mounting face of the sleeve (2). If the screws protrude, a thin
steel washer may be added under the head of the screw.
12.
With a feeler gauge, check for a 0.001 to 0.004 inch (0.03 to 0.10 mm) clearance between the cap assembly (9) and
the shim (4). Tighten the screws (11) and secure with lockwire (C-405) to the holes in the cap assembly (9).
13.
Apply dry film lubricant (C-028) to the outside diameter of the wear sleeve (19). Exercise caution to avoid coating
other parts.
14.
Install the nut (21) on the pinion (1) and hand tighten the nut.
15.
Install the wrench set (T101588) onto the adapter (20).
16.
Install the 3/4-inch (0.750)-inch (19.05-mm) square drive and 12.0 inches (305 mm) extension bar (L-122) into
the wrench set (T101588).
17.
Make sure the square drive of the extension bar (L-122) engages the pinion (1).
QUILL ASSEMBLY MUST BE WELL PADDED AND SUITABLY SUPPORTED ON WORK BENCH
DURING FOLLOWING TORQUING OPERATIONS TO AVOID DAMAGE TO QUILL.
18.
Install the torque wrench with the 3/4 (0.750)-inch (19.05-mm) square drive into the 3/4 (0.750)-inch (19.05-mm)
square drive of the wrench set (T101588) and torque 350 to 400 foot-pounds (475 to 542 Nm).
19.
Remove the extension bar (L-122) and the wrench set (T101588).
20.
Install the lock spring (22). Make sure the lock spring is fully seated in the groove in the splines of the pinion (1).
21.
Lubricate the new packing (23) and the mating surface with the same oil used in the transmission prior to assembly.
22.
Install a new packing (23) on the plate (24).
23.
Install the plate (24) and secure with the retaining ring (25).
24.
Lubricate a new packing (8) with the same oil used in the transmission and install on the union (7).
25.
Install the union (7) in the cap assembly (9). Install the cap (6) on the union.
26.
Lubricate a new packing (15) with the same oil used in the transmission and install the new packing on the plug
(14). Install the plug in the cap assembly (9).
412-A-63-10-00-17A-710A-B
Applicable to: ALL
Page 00187-2 28 OCT 2024
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BHT-412-CRO
27.
Tighten the plug (14) and secure with lockwire (C-405) to the anchor hole of the cap assembly (9).
Applicable to: ALL
412-A-63-10-00-17A-710A-B
ECCN EAR99
28 OCT 2024 Page 00187-3
BHT-412-CRO
ICN-412-A-631000-B-97499-02802-A-002-01
Figure 1. Main Input Quill Assembly (212-040-263-101) (Sheet 1 of 1)
412-A-63-10-00-17A-710A-B
Applicable to: ALL
Page 00187-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Main Input Quill (412-040-263-ALL) - Disassembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Bearing Removal Tool Set
Wrench Set
Holding Fixture
412-240-009-101
412-240-001-101
412-240-002-101
1
1
1
Remarks
Procedure
1.
Remove the retaining ring (26, Figure 1) and the cover plate (25).
2.
Remove and discard the packing (24).
3.
Remove the retaining ring (23) and the lockwasher (22).
4.
Install the holding fixture (412-240-002-101) on the quill, as shown in Figure 2.
5.
Secure a 3/4 (0.750)-inch (19.05-mm) square bar vertically in a vise and put the quill on the bar with the pinion
engaged on the bar.
6.
Loosen the nut (21, Figure 1) with the wrench set (412-240-001-101).
7.
Remove the holding fixture (412-240-002-101), wrench set (412-240-001-101), and nut (21).
8.
Remove the retaining ring (16) and remove the seal retainer (15).
9.
Remove the adapter (20) from the pinion (1).
10.
Remove the screws (18) and the washers (17).
11.
Remove the cap assembly (8) from the sleeve (3).
12.
Remove the shim (6), spacer (7), and packing (5). Discard the packing and mark the shim.
13.
Install the bearing removal tool set (412-240-009-101) (1, Figure 3) on the pinion (1, Figure 1) between the gear
and the sleeve (3).
14.
Support the bearing inner race and press the pinion (1, Figure 1) out of triplex bearings (4).
RETAIN BEARINGS AS A MATCHED SET.
15.
Support the sleeve (3) and press the triplex bearings (4) out of the sleeve by pressing on the outer race. Keep
the bearings together as a matched set.
16.
Remove the packing (2) from the pinion (1). Discard the packing.
17.
Cut and remove the lockwire.
18.
Remove the plug (10) with the packing (9) from the cap assembly (8). Discard the packing.
MAGNETIC SEAL IS MADE UP OF TWO PARTS, THE MAGNETIC RING AND THE CARBON RING.
KEEP THEM TOGETHER AS A MATCHED SET.
DO NOT HANDLE THE PARTS WITH BARE HANDS.
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
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28 OCT 2024 Page 00188-1
BHT-412-CRO
19.
Remove the magnetic seal (11) from the seal retainer (15).
20.
Remove and discard the packings (12, 13, and 14).
21.
Remove the union (27) and the packing (28) from the cap assembly (8). Discard the packing.
412-A-63-10-00-18A-530A-B
Page 00188-2 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00033-A-001-01
Figure 1. Main Input Quill Assembly (412-040-263-101 And -103) (Sheet 1 of 1)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-18A-530A-B
28 OCT 2024 Page 00188-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00187-A-001-01
Figure 2. Wrench Set (412-240-001-101) - Application (Sheet 1 of 1)
412-A-63-10-00-18A-530A-B
Page 00188-4 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00188-A-001-01
Figure 3. Bearing Removal Tool Set (412-240-009-101) - Application (Sheet 1 of 1)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-18A-530A-B
28 OCT 2024 Page 00188-5
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-18A-530A-B
Page 00188-6 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Main Input Quill (412-040-263-ALL) - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Corrosion preventive compound
Drycleaning solvent
Solvent
Clean cloth
C-105
C-304
C-334
C-516
AR
AR
AR
AR
Remarks
Procedure
1.
Clean all the quill parts with drycleaning solvent (C-304). Use a soft bristle brush to dislodge deposits. All parts
except bearings may be cleaned with solvent (C-334) by vapor degreasing.
DO NOT ALLOW BEARINGS TO SPIN WHILE DRYING.
2.
Dry the parts with a clean cloth (C-516) or dry, filtered compressed air.
DO NOT HANDLE UNOILED BEARINGS WITH BARE HANDS.
NOTE
Parts treated per the following step may be left covered in indoor storage for approximately 150 hours
without being affected by corrosion.
3.
Coat the bearings with corrosion preventive compound (C-105) immediately after cleaning (BHT-ALL-SPM, Standard
Practices Manual).
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-18A-258A-B
28 OCT 2024 Page 00189-1
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-18A-258A-B
Page 00189-2 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Main Input Quill (412-040-263-ALL) - Inspection
Procedure
NOTE
Wear limits are provided to show the required fit between mating parts. It is not intended that all
dimensions be checked as a prescribed overhaul procedure; however, parts that show evidence of wear
or physical damage must be checked dimensionally.
1.
Inspect the pinion (1, Figure 1) in accordance with Figure 2.
2.
Inspect the sleeve (3, Figure 1) in accordance with Figure 3.
3.
Inspect the triplex bearing (4, Figure 1) for spalling, scoring, pitting, brinelling, corrosion damage, cracked or broken
retainers, and roughness when rotated. Any defect is cause for rejection.
4.
Inspect the cap assembly (8) in accordance with Figure 4.
5.
Inspect the seal retainer (15, Figure 1) in accordance with Figure 5.
6.
Inspect the adapter (20, Figure 1) in accordance with Figure 6.
7.
Inspect the retaining rings (16 and 23, Figure 1) and Iockwasher (22) for obvious defects and deformation.
8.
Inspect the nut (21) for thread damage and obvious defects.
9.
Inspect the plate (25) for corrosion damage and nicks or burrs in the seal groove that could cause leakage.
THE SEAL INSPECTION PROCEDURE MUST BE ACCOMPLISHED UNDER CLEAN CONDITIONS.
WEAR WHITE COTTON GLOVES WHILE HANDLING SEAL. DO NOT SLIDE MAGNETIC SEAL
ON MAGNETIC RING. DO NOT ALLOW CARBON SEALING SURFACE OR SEALING RING
ON MAGNETIC RING TO CONTACT ANY OTHER OBJECT. DO NOT ALLOW ANY FOREIGN
PARTICLES TO CONTACT SEAL.
NOTE
The magnetic seal is made up of two parts, the magnetic ring and the carbon ring, which is bonded to the
seal case.
10.
Inspect the magnetic seal as follows:
10.1.
Measure the gap between the magnetic ring and the seal case with a clean, non-metallic feeler gauge (Figure 7,
Figure 8, and Figure 9, as applicable).
10.2.
Separate the magnetic ring from the carbon ring by carefully pulling directly away from each other.
10.3.
Inspect the magnetic ring with a high intensity light for scratches, nicks, and cracks. A cracked ring is nonrepairable
and must be replaced.
10.4.
Inspect the magnetic ring back face and l.D. surface conditions as follows:
10.4.1.
Porosity holes and voids under 0.020 inch (0.51 mm) in diameter are permitted if less than 0.020 inch (0.51 mm)
deep. Zones of porosity shall not extend more than 1/4 of the way across any surface and shall not extend to
within 0.070 inch (1.78 mm) of any edge.
10.4.2.
Edge chips on the inside diameter and the outside diameter of the back face are permitted if they are less than 0.0625
inch (1.588 mm) long and 0.020 inch (0.51 mm) wide.
10.4.3.
No cracks are permitted.
10.5.
Inspect the magnetic ring outside diameter surface as follows:
10.5.1.
Zones of porosity shall not extend more than 1/4 of the way across any surface and shall not extend to within
0.070 inch (1.78 mm) of any edge.
10.5.2.
Porosity holes are permitted if less than 0.020 inch (0.51 mm) in diameter and less than 0.020 inch (0.51 mm) deep.
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-18A-280A-B
28 OCT 2024 Page 00190-1
BHT-412-CRO
10.5.3.
Edge chips are permitted if less than 0.0312 inch (0.793 mm) long and 0.0156 inch (0.396 mm) wide.
10.5.4.
No cracks are permitted.
10.6.
Inspect the magnetic ring sealing face as follows:
10.6.1.
The sealing ring is defined as the ring that coincides with the mating carbon sealing surface plus an additional 0.020
inch (0.51 mm) per side allowance. Chips, nicks, and scratches are not allowed on the sealing ring.
10.6.2.
The sealing ring shall be free of porosity holes and pits unless they are within the limits per Figure 10 and Figure 8, as
applicable. Pits and porosity holes must be clean and free of foreign matter. No two pits and/or porosity holes may
be aligned radially across the sealing ring.
10.6.3.
Porosity holes outside the sealing ring are permitted if less than 0.020 inch (0.51 mm) in diameter and less than
0.016 inch (0.41 mm) deep. Zones of porosity shall not extend more than 1/4 of the way across any surface and shall
not extend within 0.070 inch (1.78 mm) of any edge.
10.6.4.
Scratches outside the sealing ring are permitted.
10.6.5.
Chipping on the inside diameter and the outside diameter edges is permitted provided it is outside the sealing ring
and is less than 0.0625 inch (1.588 mm) long and 0.020 inch (0.51 mm) wide.
10.7.
Inspect the seal case and carbon ring assembly under a high intensity light. Minor scratches and nicks are permitted
on the seal case. The sealing surface of the carbon must show no visible scratches or pits when viewed under a
high intensity light. Damage on the edges of the carbon sealing surface is allowable if no two damaged areas are
aligned with one another in the radial direction and if the number and size of the damaged areas are within the carbon
seal edge damage limits shown in Figure 7 and Figure 8, as applicable.
10.8.
Inspect the packing groove and remove any foreign particles. The groove shall not have any burrs that might
damage the packing.
DO NOT SLIDE SEAL MATING SURFACES AGAINST EACH OTHER AT ANY TIME. DO NOT TOUCH
EITHER SEALING SURFACE WITH ANY FOREIGN OBJECT.
10.9.
Reassemble the seal by lining up the two seal halves to their final assembled position and carefully allow the two
halves to pull together into their assembled position.
NOTE
Wear limits are provided to show required fit between mating parts. It is not intended that all dimensions
be checked as a prescribed overhaul procedure; however, parts that show evidence of wear or physical
damage must be checked dimensionally.
11.
Inspect the quill assembly parts dimensionally in accordance with Figure 10 and replace parts that do not conform
to the inspection limits.
12.
Inspect the following parts by magnetic particle inspection (Code M) or fluorescent penetrant inspection (Code F), as
applicable. Demagnetize parts after magnetic particle inspection. Refer to Table 2 and the BHT-ALL-SPM, Standard
Practices Manual for procedure.
Figure 1INDEX NUMBER
NOMENCLATURE
CODE
1
Pinion
M
3
Sleeve
M
8
Cap Assembly
F
15
Seal Retainer
F
20
Adapter
M
21
Nut
M
Table 2. Magnetic Particle Inspection
PART NUMBER
NOMENCLATURE
ITEM AND FIGURE
412-A-63-10-00-18A-280A-B
Page 00190-2 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Table 2. Magnetic Particle Inspection (continued)
SET UP AND MAGNETIZATION CURRENT REQUIREMENTS
412-040-700-101, -103 and -105
Pinion
1, Figure 1
SET UP:
Place part over a 1.0-inch (25-mm) diameter central conductor.
Current for primary diameters, magnetize at 4350 amps.
Optional current for secondary diameters, magnetize at 1130 amps.
Omit coil shot.
412-040-137-101
Sleeve
3, Figure 1
SET UP:
Place part over a 2.0-inches (51-mm) diameter central conductor.
Current for primary diameters, magnetize at 3520 amps.
Optional current for secondary diameters, magnetize at 1960 amps.
Large I.D. of part: Magnetize at four approximately equally spaced radial locations on central conductor.
SET UP: 5 TURN COIL SHOT:
Disc-shaped portion of part: Lay part flat in bottom of coil.
Magnetize at 3000 amps.
Rotate part 1/4 turn and repeat.
412-040-136-101
Adapter
20, Figure 1
SET UP:
Place part over a 2.0-inches (51-mm) diameter central conductor.
Current for primary diameters, magnetize at 4570 amps.
Optional current for secondary diameters, magnetize at 1610 amps.
SET UP: 5 TURN COIL SHOT:
Disc-shaped portion of part: Lay part flat in bottom of coil.
Magnetize at 3000 amps.
Rotate part 1/4 turn and repeat.
214-040-914-103
Nut
21, Figure 1
SET UP:
Place part over a 2.0-inches (51-mm) diameter central conductor.
Current for magnetize at 1690 amps.
Omit coil shot.
214-040-097-003
Sleeve
3, Figure 1
SET UP:
Place part over a 2.0-inches (51-mm) diameter central conductor.
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-18A-280A-B
28 OCT 2024 Page 00190-3
BHT-412-CRO
Table 2. Magnetic Particle Inspection (continued)
Current for primary diameters, magnetize at 3460 amps.
Optional current for secondary diameters, magnetize at 1960 amps.
Large I.D. of part: Magnetize at four approximately equally spaced radial locations on central conductor.
SET UP: 5 TURN COIL SHOT:
Disc-shaped portion of part: Place part in bottom of coil.
Magnetize at 3000 amps.
Rotate part 1/4 turn and repeat.
NOTES:
1. Magnetization currents provided are applicable to magnetic particle inspection apparatus using Direct Current (DC) . If an
Alternating Current (AC) apparatus is used, adjust the current as follows: AC= 0.667 x DC.
2. Ferrous parts requiring magnetic particle inspection that are not addressed in the attached material, are to be inspected in
accordance with the general procedures outlined in ASTM E1444 standard practices (BHT-ALL-SPM, Chapter 6, Standard
Practices Manual).
3. Part numbers listed apply to all successive dash numbers for that component unless otherwise specified.
412-A-63-10-00-18A-280A-B
Page 00190-4 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00033-A-001-01
Figure 1. Main Input Quill Assembly (412-040-263-101 and -103) (Sheet 1 of 1)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-18A-280A-B
28 OCT 2024 Page 00190-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00189-A-002-01
Figure 2. Main Input Quill Pinion - Damage Limits (Sheet 1 of 2)
412-A-63-10-00-18A-280A-B
Page 00190-6 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00190-A-001-01
Figure 2. Main Input Quill Pinion - Damage Limits (Sheet 2 of 2)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-18A-280A-B
28 OCT 2024 Page 00190-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00191-A-001-01
Figure 3. Main Input Quill Sleeve - Damage Limits (Sheet 1 of 1)
412-A-63-10-00-18A-280A-B
Page 00190-8 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00192-A-001-01
Figure 4. Main Input Quill Cap Assembly - Damage Limits (Sheet 1 of 1)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-18A-280A-B
28 OCT 2024 Page 00190-9
BHT-412-CRO
ICN-412-A-631000-B-97499-00193-A-001-01
Figure 5. Main Input Quill Seal Retainer - Damage Limits (Sheet 1 of 1)
412-A-63-10-00-18A-280A-B
Page 00190-10 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00194-A-001-01
Figure 6. Input Adapter (412-040-136-101 and -103) - Damage Limits (Sheet 1 of 1)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-18A-280A-B
28 OCT 2024 Page 00190-11
BHT-412-CRO
ICN-412-A-631000-B-97499-00175-A-001-01
Figure 7. Magnetic Seal - Damage Limits (Sheet 1 of 1)
412-A-63-10-00-18A-280A-B
Page 00190-12 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00176-A-001-01
Figure 8. Seal Case and Carbon Sealing Element (412-040-111-105 and -107) - Damage Limits (Sheet 1 of 3)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-18A-280A-B
28 OCT 2024 Page 00190-13
BHT-412-CRO
ICN-412-A-631000-B-97499-00177-A-001-01
Figure 8. Seal Case and Carbon Sealing Element (412-040-111-105 and -107) - Damage Limits (Sheet 2 of 3)
412-A-63-10-00-18A-280A-B
Page 00190-14 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00178-A-001-01
Figure 8. Seal Case and Carbon Sealing Element (412-040-111-105 and -107) - Damage Limits (Sheet 3 of 3)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-18A-280A-B
28 OCT 2024 Page 00190-15
BHT-412-CRO
ICN-412-A-631000-B-97499-00179-A-001-01
Figure 9. Magnetic Seal (412-040-111-105 and -107) - Damage Limits (Sheet 1 of 2)
412-A-63-10-00-18A-280A-B
Page 00190-16 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00180-A-001-01
Figure 9. Magnetic Seal (412-040-111-105 and -107) - Damage Limits (Sheet 2 of 2)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-18A-280A-B
28 OCT 2024 Page 00190-17
BHT-412-CRO
ICN-412-A-631000-B-97499-00195-A-001-01
Figure 10. Main Input Quill Assembly - Wear Limits (Sheet 1 of 2)
412-A-63-10-00-18A-280A-B
Page 00190-18 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00196-A-001-01
Figure 10. Main Input Quill Assembly - Wear Limits (Sheet 2 of 2)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-18A-280A-B
28 OCT 2024 Page 00190-19
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-18A-280A-B
Page 00190-20 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Main Input Quill (412-040-263-ALL) - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Zinc chromate primer
Abrasive cloth or paper
India stone
C-201
C-406
C-464
AR
AR
AR
Remarks
Procedure
1.
Polish out minor dents and nicks on the sleeve (3, Figure 1) flange top surface with a fine india stone (C-464). Blend
repaired area into the flat surface with a minimum radius of 0.12 inch (3.0 mm). The finished repair must be 32 RHR
or better. The maximum depth, after repair, must not exceed 0.030 inch (0.76 mm).
2.
Polish out minor dents, nicks, and scratches on the exterior surfaces of the cap assembly (8) with abrasive cloth or
paper (C-406). Replace a loose or deformed pin (19). Coat the pin with unreduced zinc chromate primer (C-201)
immediately prior to installation.
3.
Polish out minor nicks, dents, and scratches on the curvic adapter (20) with a fine india stone (C-464).
4.
Polish out minor nicks, dents, and scratches on seal retainer (15) with abrasive cloth or paper (C-406).
5.
Polish out minor nicks, dents, and scratches on plate (25) with abrasive cloth or paper (C-406).
NOTE
If you return the part to Bell Helicopter Textron (BHT) , refer to General Information Letter (IL) GEN-04-98
for applicable shipping information and to obtain a Return Material Authorization (RMA) number.
6.
Repair of the magnetic seal by the user is not permitted. If there is evidence of damage, return the part to the
manufacturer, one of its authorized service centers, or Bell for evaluation and possible repair.
7.
Repair pinion (1) as follows:
7.1.
Remove any raised material on noncontact surfaces with a fine india stone (C-464).
7.2.
Repair nicks, dents, and scratches on the spline teeth by smoothing out with a fine india stone (C-464). Do not
exceed limits defined in Figure 2.
DO NOT STRIP GEAR TEETH OR SPLINES DURING COPPER STRIPPING OPERATION. MASK GEAR
TEETH AND SPLINES TO PREVENT ACCUMULATIONS OF COPPER DEPOSITS DURING COPPER
PLATING OPERATIONS.
7.3.
Strip and replace the copper plating as follows (BHT-ALL-SPM, Standard Practices Manual):
7.3.1.
Strip the copper plating on the triplex bearing journal (Figure 3).
7.3.2.
The outside diameter of the triplex bearing journal should be 3.1501 to 3.1503 inches (80.013 to 80.017 mm) before
the copper plating and 3.1511 to 3.1515 inches (80.038 to 80.048 mm) after the copper plating. The copper plating
shall be 0.0003 to 0.0007 inch (0.008 to 0.017 mm) thick after plating (Figure 3).
8.
Refinish the parts (except the pinion) after repair in accordance with Figure 4.
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-18A-685A-B
28 OCT 2024 Page 00191-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00033-A-001-01
Figure 1. Main Input Quill Assembly (412-040-263-101, And -103) (Sheet 1 of 1)
412-A-63-10-00-18A-685A-B
Page 00191-2 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00189-A-002-01
Figure 2. Main Input Quill Pinion - Damage Limits (Sheet 1 of 2)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-18A-685A-B
28 OCT 2024 Page 00191-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00190-A-001-01
Figure 2. Main Input Quill Pinion - Damage Limits (Sheet 2 of 2)
412-A-63-10-00-18A-685A-B
Page 00191-4 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00197-A-001-01
Figure 3. Main Input Quill Pinion - Copper Plating Area (Sheet 1 of 1)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-18A-685A-B
28 OCT 2024 Page 00191-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00198-A-001-01
Figure 4. Main Input Quill Processing Requirements (Sheet 1 of 2)
412-A-63-10-00-18A-685A-B
Page 00191-6 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00199-A-001-01
Figure 4. Main Input Quill Processing Requirements (Sheet 2 of 2)
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-18A-685A-B
28 OCT 2024 Page 00191-7
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-18A-685A-B
Page 00191-8 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Main Input Quill (412-040-263-ALL) - Assembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Wrench Set
Holding Fixture
412-240-001-101
412-240-002-101
1
1
Remarks
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Grease
Lubricating oil
Assembly fluid
Corrosion preventive compound
Lockwire
Clean cloth
C-001
C-011
C-024
C-128
C-405
C-516
AR
AR
AR
AR
AR
AR
Remarks
Procedure
1.
Make sure that all the parts have been cleaned (412-A-63-10-00-18A-258A-B / 00189).
DO NOT HANDLE UNOILED PARTS WITH BARE HANDS.
2.
Coat the triplex bearing (4, Figure 1), sleeve (3), and pinion (1) with approved transmission oil and allow to drain.
Refer to the BHT-412-MM for approved lubricants.
3.
Align the V-marks on the outer races of the triplex bearing (4) and the sleeve (3) and press the bearings into the
sleeve with the apex of the V pointing as shown in Figure 1.
IF BEARINGS MUST BE REMOVED FROM PINION FOR ANY REASON AFTER INSTALLATION, THE
COPPER PLATING SHALL BE INSPECTED. IF THE PLATING IS SCRATCHED OR GOUGED, IT
MUST BE STRIPPED AND REPLACED BEFORE THE BEARING, OR ITS REPLACEMENT, CAN BE
INSTALLED (412-A-63-10-00-18A-685A-B / 00191).
NOTE
If the bearings or the pinion were replaced, it is necessary to vibro-etch index marks (lines) on a new part
the same as on the part replaced, so that the bearings may be checked for spinning after the test run.
If the bearings are replaced, be sure that dull burr marks on the inner races are aligned when the index
marks are vibro-etched on the races.
4.
Install the pinion (1) in the triplex bearing (4) as follows:
4.1.
Remove the oil from the bore of the triplex bearing (4) and the journal of the pinion (1) with a clean cloth (C-516).
DO NOT EXCEED THE MAXIMUM ALLOWABLE TEMPERATURE WHEN YOU HEAT A PART OR
DAMAGE TO THE PART MAY OCCUR.
4.2.
Uniformly heat the triplex bearing (4) assembly 230 to 250°F (110 to 121°C).
4.3.
Align the marks on the three bearing inner rings with the mark on the spline of the pinion.
4.4.
Support the triplex bearing inner races.
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-18A-710A-B
28 OCT 2024 Page 00192-1
BHT-412-CRO
4.5.
Press the pinion through the bearing until fully seated against the bearing inner race.
4.6.
Hold 18 to 20 tons (160.1360 to 177.9289 N) pressure on the pinion until the assembly has cooled to approximately
room temperature.
4.7.
Wipe the triplex bearing (4) assembly and the pinion (1) journal diameter free of oil.
4.8.
Lubricate the pinion (1) and the triplex bearing (4) with the same oil used in the transmission.
5.
Check the pinion (1) and the triplex bearing (4) for free rotation.
6.
Temporarily install the cap assembly (8) on the sleeve (3) the with spacer (7), as applicable, without the packing
(5) or the shim (6).
7.
Support the sleeve (3) and apply light pressure to the flange of the cap assembly (8).
8.
With a feeler gauge, measure the clearance between the cap assembly (8) and the spacer (7), if installed, or the
sleeve (3).
9.
Measure the thickness of the laminated shim (6). Peel the shims to obtain a clearance of 0.001 to 0.004 inch (0.03 to
0.10 mm) between the cap assembly (8) and the spacer (7), if installed, or the sleeve (3).
10.
Lubricate the new packing (5) with the same oil used in the transmission and install on the sleeve (3).
NOTE
Allow the previously assembled cap assembly (8) and adapter (20) to remain on the work bench with the
large end of the adapter down. This will prevent the carbon ring from sliding off the adapter shaft during
assembly.
11.
Lubricate the new packing (2) and the pinion (1) contact diameter with approved transmission oil. Install the packing
on the pinion.
12.
Apply a thin even coat of corrosion preventive compound (C-128) to the mating flanges of the cap assembly (8),
spacer (7), shim (6), and sleeve (3).
13.
Put the new shim (6) and the spacer (7) on the cap assembly (8) and the adapter (20) by aligning the splines of
the pinion (1) with splines of the adapter. Align the screw holes and install the screws (18) and the washers (17).
Tighten the screws and secure with lockwire (C-405).
KEEP SEAL IN ORIGINAL PACKAGING UNTIL READY FOR INSTALLATION. WHEN SEAL
PACKAGE IS OPENED, SEPARATE SEAL BY PULLING MAGNETIC RING AND CARBON RING
STRAIGHT AWAY FROM EACH OTHER. SLIDING BETWEEN SEAL HALVES MAY DAMAGE
MATING SURFACES. DO NOT PLACE MAGNETIC RING OR CARBON RING IN AREA WHERE
THEY MAY ATTRACT METAL PARTICLES. INSTALL SEAL BY HAND PRESSING ONLY. PRIOR TO
INSTALLATION OF SEAL, LUBRICATE PACKINGS AND MATING DIAMETERS SPARINGLY WITH
assembly fluid (C-024).
14.
Lubricate the new packings (13 and 14) and the seal retainer (15) contact diameters with assembly fluid (C-024).
15.
Install the packings (13 and 14) on the seal retainer (15) and install the seal retainer over the adapter (20).
KEEP NEW MAGNETIC SEAL IN ORIGINAL PACKAGING UNTIL INSTALLATION. IF SEAL IS NOT
IN PACKAGE DO NOT ALLOW SLIDING BETWEEN SEAL HALVES. DO NOT PLACE SEAL IN AREA
WHERE THEY MAY ATTRACT METAL PARTICLES. DO NOT ALLOW ULTRACHEM ASSEMBLY
FLUID TO CONTACT CARBON SEALING SURFACE. INSTALL SEAL BY HAND PRESSING ONLY.
NOTE
The magnetic seal is made up of two parts, the carbon ring and the magnetic ring.
16.
Lubricate a new packing (12) and the mating diameters of the magnetic seal (11) with assembly fluid (C-024). Install
the packing in the carbon ring and install the magnetic seal over the adapter (20) inside the cap assembly (8).
412-A-63-10-00-18A-710A-B
Page 00192-2 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
17.
Press the adapter (20) into the cap assembly (8) and align the seal retainer (15) slot with the cap alignment pin (19)
and install the seal retainer on cap assembly.
18.
Install the holding fixture (412-240-002-101) on the flange of the adapter (20) and secure in a vise.
19.
Lubricate the nut (21) threads with grease (C-001) and the nut flange with lubricating oil (C-011).
20.
Install the nut (21) and torque the nut 450 to 500 foot-pounds (610 to 678 Nm) with the wrench set (412-240-001-101).
21.
Remove the nut (21), wipe clean, and repeat Step 19. and Step 20..
22.
Remove the holding fixture (412-240-002-101) and the wrench set (412-240-001-101).
23.
Install the lockwasher (22) and the retaining ring (23).
24.
Push the seal retainer (15) down into the cap assembly (8) and install the retaining ring (16).
25.
Put the new packing (24) on the plate (25). Lubricate the packing and the mating surface with the same oil used in the
transmission prior to assembly. Install the plate and secure with the retaining ring (26).
26.
Lubricate a new packing (28) with the same oil used in the transmission and install the packing on the union (27).
Install the union in the cap assembly (8).
27.
Lubricate a new packing (9) with the same oil used in the transmission and install the packing on the plug (10). Install
the plug in the cap assembly (8).
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-18A-710A-B
28 OCT 2024 Page 00192-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00033-A-001-01
Figure 1. Main Input Quill Assembly (412-040-263-101 and -103) (Sheet 1 of 1)
412-A-63-10-00-18A-710A-B
Page 00192-4 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or SN:
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Generator (or SYS 2 Hydraulic Pump) Drive Quill (204-040-379-003 and -101) - Disassembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Wrench Assembly
Bar
Holding Fixture
Wrench
Plate Assembly
T101305
T101334
T101447
T101449
T101519
1
1
1
1
1
Remarks
Procedure
1.
Place the quill in the holding fixture (T101447) with the pinion (12, Figure 1) facing down.
2.
Remove the nut (7) with the wrench (T101449).
3.
Press the seal (8) out of the nut (7) and remove the packing (6). Discard the seal and the packing.
4.
Remove the clip (5).
5.
Remove the nut (4) with the wrench assembly (T101305) and the back of the plate assembly (T101519).
6.
Remove the washer (3).
7.
Support the duplex bearing (1) on the inner race with the plate assembly (T101519).
8.
Press the pinion (12) out of the sleeve (9).
9.
Remove the cork (13) from the pinion (12). Discard the cork.
10.
Press the duplex bearing (1) and the spacer set (2) out of the sleeve (9) with the bar (T101334).Keep the duplex
bearings and spacer set together as a set.
11.
Remove the three screws (11) and the shim plate (10). Mark the shim plate for installation on the same sleeve.
Applicable to: ALL
412-A-63-10-00-19A-530A-B
ECCN EAR99
31 MAY 2023 Page 00193-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00021-A-001-01
Figure 1. Generator (or SYS 2 Hydraulic Pump) Drive Quill (Sheet 1 of 1)
412-A-63-10-00-19A-530A-B
Applicable to: ALL
Page 00193-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Generator (or SYS 2 Hydraulic Pump) Drive Quill (204-040-379-003 and -101) - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Corrosion preventive compound
Drycleaning solvent
Solvent
Clean cloth
C-105
C-304
C-334
C-516
AR
AR
AR
AR
Remarks
Procedure
1.
Inspect the quill for corrosion damage to the threaded studs and stud holes before cleaning. No structural damage to
the threads or holes is permitted.
2.
Clean all the parts with drycleaning solvent (C-304). Use a soft bristle brush to dislodge stubborn deposits. All parts
except the bearings may be cleaned with solvent (C-334) by vapor degreasing if desired.
DO NOT ALLOW BEARINGS TO SPIN WHILE DRYING.
3.
Dry the parts with a clean cloth (C-516) or dry filtered compressed air.
NOTE
Parts treated per the following step may be left covered in indoor storage for approximately 150 hours
without being affected by corrosion.
4.
Immediately after cleaning the bearings with drycleaning solvent (C-304), gently agitate the bearings in corrosion
preventive compound (C-105) and allow to drain dry. Apply a coat of lubricating oil of the type used in the
transmission to the bearings.
5.
Remove the sealant from the quill parts with a plastic scraper.
Applicable to: ALL
412-A-63-10-00-19A-258A-B
ECCN EAR99
31 MAY 2023 Page 00194-1
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-19A-258A-B
Applicable to: ALL
Page 00194-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Generator (or SYS 2 Hydraulic Pump) Drive Quill (204-040-379-003 and -101) - Inspection
Procedure
NOTE
Wear limit dimensions shown in Figure 1 are provided to show the required fit between mating parts. It is
not intended that all dimensions listed on the illustration be checked as a prescribed overhaul procedure;
however parts that show evidence of wear or physical damage must be checked dimensionally.
1.
Inspect the pinion (12, Figure 2) in accordance with Figure 3.
2.
Inspect the duplex bearings (1, Figure 2) for spalling, scoring, pitting, brinelling, and corrosion damage. Damage that
can be detected visually is not permitted.
3.
Inspect the following parts by magnetic particle inspection (Code M) or fluorescent penetrant inspection (Code
F), as applicable. Demagnetize the parts after the magnetic particle inspection. Refer to Table 2 and the
BHT-ALL-SPM, Standard Practices Manual for the procedure.
Figure 2INDEX NUMBER
NOMENCLATURE
CODE
4
Nut
M
7
Nut
F
9
Sleeve
F
12
Pinion
M
Table 2. Magnetic Particle Inspection
PART NUMBER
NOMENCLATURE
ITEM AND FIGURE
SET UP AND MAGNETIZATION CURRENT REQUIREMENTS
HP/EP GENERATOR (OR SYS 2 HYDRAULIC PUMP) DRIVE QUILL (204-040-379-101)
412-040-302-101
Pinion
12, Figure 2
SET UP:
Place part over a 0.7-inch (18-mm) diameter central conductor.
Current for primary diameters, magnetize at 3680 amps.
Optional current for secondary diameters, magnetize at 1020 amps.
CENTRAL CONDUCTOR MAY GET HOT.
Omit coil shot.
204-040-412-001
Nut
4, Figure 2
SET UP:
Place part over a 1.0-inch (25-mm) diameter central conductor.
Current for primary diameters, magnetize at 972 amps.
Omit coil shot.
GENERATOR (OR SYS 2 HYDRAULIC PUMP) DRIVE QUILL (204-040-379-003)
204-040-102-017
Pinion
12, Figure 2
SET UP:
Place part over a 0.7-inch (18-mm) diameter central conductor.
Current for primary diameters, magnetize at 3680 amps.
Applicable to: ALL
412-A-63-10-00-19A-280A-B
ECCN EAR99
31 MAY 2023 Page 00195-1
BHT-412-CRO
Table 2. Magnetic Particle Inspection (continued)
Optional current for secondary diameters, magnetize at 1020 amps.
CENTRAL CONDUCTOR MAY GET HOT.
Omit coil shot.
204-040-412-001
Nut
4, Figure 2
SET UP:
Place part over a 1.0-inch (25-mm) diameter central conductor.
Current for primary diameters, magnetize at 972 amps.
Omit coil shot.
NOTES:
1. Magnetization currents provided are applicable to magnetic particle inspection apparatus using Direct Current (DC) . If an
Alternating Current (AC) apparatus is used, adjust the current as follows: AC= 0.667 x DC.
2. Ferrous parts requiring magnetic particle inspection that are not addressed in the attached material, are to be inspected in
accordance with the general procedures outlined in ASTM E1444 standard practices (BHT-ALL-SPM, Chapter 6, Standard
Practices Manual).
3. Part numbers listed apply to all successive dash numbers for that component unless otherwise specified.
4.
Inspect the sleeve (9, Figure 2) in accordance with Figure 4.
412-A-63-10-00-19A-280A-B
Applicable to: ALL
Page 00195-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00200-A-001-01
Figure 1. Generator (or SYS 2 Hydraulic Pump) Drive Quill - Wear Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-19A-280A-B
ECCN EAR99
31 MAY 2023 Page 00195-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00021-A-001-01
Figure 2. Generator (or SYS 2 Hydraulic Pump) Drive Quill (Sheet 1 of 1)
412-A-63-10-00-19A-280A-B
Applicable to: ALL
Page 00195-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00201-A-001-01
Figure 3. Generator (or SYS 2 Hydraulic Pump) Drive Quill Pinion Assembly - Damage Limits (Sheet 1 of 2)
Applicable to: ALL
412-A-63-10-00-19A-280A-B
ECCN EAR99
31 MAY 2023 Page 00195-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00202-A-001-01
Figure 3. Generator (or SYS 2 Hydraulic Pump) Drive Quill Pinion Assembly - Damage Limits (Sheet 2 of 2)
412-A-63-10-00-19A-280A-B
Applicable to: ALL
Page 00195-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00204-A-001-01
Figure 4. Generator (or SYS 2 Hydraulic Pump) Drive Quill Sleeve - Damage Limits (Sheet 1 of 4)
Applicable to: ALL
412-A-63-10-00-19A-280A-B
ECCN EAR99
31 MAY 2023 Page 00195-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00205-A-001-01
Figure 4. Generator (or SYS 2 Hydraulic Pump) Drive Quill Sleeve - Damage Limits (Sheet 2 of 4)
412-A-63-10-00-19A-280A-B
Applicable to: ALL
Page 00195-8 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00206-A-001-01
Figure 4. Generator (or SYS 2 Hydraulic Pump) Drive Quill Sleeve - Damage Limits (Sheet 3 of 4)
Applicable to: ALL
412-A-63-10-00-19A-280A-B
ECCN EAR99
31 MAY 2023 Page 00195-9
BHT-412-CRO
ICN-412-A-631000-B-97499-00207-A-001-01
Figure 4. Generator (or SYS 2 Hydraulic Pump) Drive Quill Sleeve - Damage Limits (Sheet 4 of 4)
412-A-63-10-00-19A-280A-B
Applicable to: ALL
Page 00195-10 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Generator (or SYS 2 Hydraulic Pump) Drive Quill (204-040-379-003 and -101) - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Chromic acid treatment
Shellac varnish
C-103
C-211
AR
AR
Remarks
Procedure
1.
Install the new cork (13, Figure 1) in the position shown in Figure 2, 0.25 to 0.31 inch (6.4 to 7.9 mm) in depth from
the flat surface of the gear web and coat with shellac varnish (C-211).
2.
Remove the loose or damaged studs and inserts on the quill sleeve (9, Figure 1). Install the new studs and/or the
inserts (BHT-ALL-SPM, Standard Practices Manual).
3.
Polish out mechanical and corrosion damage that is within the limits noted in Figure 2 through Figure 4.
4.
Immediately after corrosion removal and/or polishing out mechanical damage, apply the chromic acid treatment
(C-103) (BHT-ALL-SPM, Standard Practices Manual).
CORROSION REMOVAL PROCESS MUST BE MONITORED TO MAKE SURE THAT MACHINED
DIMENSIONS ARE MAINTAINED AND THAT CADMIUM PLATING IS NOT REMOVED FROM STUDS.
5.
Touch up the cadmium plated parts. Refer to the BHT-ALL-SPM, Standard Practices Manual for the prescribed
method. The shim plate (10, Figure 1) thickness must be maintained after touch-up.
Applicable to: ALL
412-A-63-10-00-19A-685A-B
ECCN EAR99
31 MAY 2023 Page 00196-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00021-A-001-01
Figure 1. Generator (or SYS 2 Hydraulic Pump) Drive Quill (Sheet 1 of 1)
412-A-63-10-00-19A-685A-B
Applicable to: ALL
Page 00196-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00200-A-001-01
Figure 2. Generator (or SYS 2 Hydraulic Pump) Drive Quill - Wear Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-19A-685A-B
ECCN EAR99
31 MAY 2023 Page 00196-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00201-A-001-01
Figure 3. Generator (or SYS 2 Hydraulic Pump) Drive Quill Pinion Assembly - Damage Limits (Sheet 1 of 2)
412-A-63-10-00-19A-685A-B
Applicable to: ALL
Page 00196-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00202-A-001-01
Figure 3. Generator (or SYS 2 Hydraulic Pump) Drive Quill Pinion Assembly - Damage Limits (Sheet 2 of 2)
Applicable to: ALL
412-A-63-10-00-19A-685A-B
ECCN EAR99
31 MAY 2023 Page 00196-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00204-A-001-01
Figure 4. Generator (or SYS 2 Hydraulic Pump) Drive Quill Sleeve - Damage Limits (Sheet 1 of 4)
412-A-63-10-00-19A-685A-B
Applicable to: ALL
Page 00196-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00205-A-001-01
Figure 4. Generator (or SYS 2 Hydraulic Pump) Drive Quill Sleeve - Damage Limits (Sheet 2 of 4)
Applicable to: ALL
412-A-63-10-00-19A-685A-B
ECCN EAR99
31 MAY 2023 Page 00196-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00206-A-001-01
Figure 4. Generator (or SYS 2 Hydraulic Pump) Drive Quill Sleeve - Damage Limits (Sheet 3 of 4)
412-A-63-10-00-19A-685A-B
Applicable to: ALL
Page 00196-8 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00207-A-001-01
Figure 4. Generator (or SYS 2 Hydraulic Pump) Drive Quill Sleeve - Damage Limits (Sheet 4 of 4)
Applicable to: ALL
412-A-63-10-00-19A-685A-B
ECCN EAR99
31 MAY 2023 Page 00196-9
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-19A-685A-B
Applicable to: ALL
Page 00196-10 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Generator (or SYS 2 Hydraulic Pump) Drive Quill (204-040-379-003 and -101) - Assembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Wrench Assembly
Holding Fixture
Wrench
Plate Assembly
T101305
T101447
T101449
T101519
1
1
1
1
Remarks
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Drycleaning solvent
Sealant
Lockwire
C-304
C-328
C-405
AR
AR
AR
Remarks
Procedure
1.
Clean all the parts with drycleaning solvent (C-304) and drain.
2.
Coat all the parts with the same oil used in the transmission and drain.
DO NOT HANDLE UNOILED PARTS WITH BARE HANDS
NOTE
Cadmium plating on the shim plate (10, Figure 1) must be intact and the serial number on the shim plate
must match the serial number on the quill sleeve (9).
3.
Inspect the shim plate (10) and the sleeve (9) for an etched serial number. If the same serial number is on both parts
and the shim plate is serviceable, install the shim plate on the sleeve with the three screws (11).
4.
If the shim plate (10) is not serviceable or the serial number is missing or illegible, determine the required dimension
of the shim as follows:
4.1.
Inspect the sleeve (9) for a reference dimension, which will be metal stamped or vibro-etched on the part adjacent to
the mounting surface. Record the dimension and where it is located on the sleeve.
4.2.
Measure the thickness of the shim plate (10) and record.
4.3.
Subtract the shim plate (10) thickness from the reference dimension noted in step a. The resulting value must be
within 2.2215 to 2.2220 inches (56.426 to 56.438 mm). This value includes the thickness of the cadmium plating
on the shim plate.
4.4.
Procure a shim plate (10) of the correct dimension determined in Step 4.3.. Install the shim plate on the sleeve
(9) with the three screws (11).
DUPLEX BEARING (1) SET AND SPACER SET (2) MUST BE INSTALLED AS MATCHED SETS.
5.
Inspect the duplex bearing (1) set to make sure the serial number on both bearings is the same. Inspect the spacer
set (2) to make sure the serial number on both spacers is the same.
6.
Put the sleeve (9) with the studs facing up.
Applicable to: ALL
412-A-63-10-00-19A-710A-B
ECCN EAR99
31 MAY 2023 Page 00197-1
BHT-412-CRO
7.
Put one bearing of the duplex bearing (1) set on the sleeve (9) with the thrust side of the outer race facing up. Use a
metal plug or cylinder of the correct outside diameter to apply force to the outer race of the bearing during the
pressing operation. Press the bearing into the sleeve.
8.
Put both parts of the spacer set (2) in the sleeve (9).
9.
Put the second bearing of the duplex bearing (1) set on the sleeve (9) with the thrust side of outer race facing down
so the bearing set will be installed back-to-back. Use a metal plug or cylinder of the correct outside diameter to apply
force to the outer race of the bearing during the pressing operation. Press the bearing into the sleeve.
WHEN INSTALLING PINION INTO BEARINGS, USE CARE TO ONLY APPLY PRESSURE TO THE
PINION HUB AREA. PRESSURE APPLIED AT GEAR TEETH CAN RESULT IN CRACKS BETWEEN
THE HOLE IN THE WEB AND POSSIBLE FAILURE OF THE PINION IN SERVICE.
MAKE SURE THE INNER SPACER OF THE SPACER SET IS CORRECTLY ALIGNED OR DAMAGE
TO THE PARTS MAY OCCUR.
10.
Use a metal cylinder of the correct diameter and wall thickness to support the inner race of the duplex bearing (1) set
and permit passage of the bearing journal part of the pinion (12). Put the parts assembled in Step 6. and Step 8. on
the metal cylinder. Press the pinion into position in the bearing set and the sleeve.
11.
Put the plate assembly (T101519) in a vise with the short end of the pins up.
12.
Put the pinion (12) on the plate with the holes of pinion engaged on the pins.
13.
Coat the threads with the same oil used in the transmission and install the washer (3) and the nut (4) with the
shoulder side of the nut next to the washer. Torque the nut 30 to 40 foot-pounds (41 to 54 Nm) with the wrench
assembly (T101305).
14.
Install the clip (5). Make sure that the tangs of the clip are properly engaged.
15.
Apply a thin film of sealant (C-328) to the outer surface of the new seal (8). Press the seal into the nut (7) with the lip
of the seal facing inboard. Wipe off excess sealant.
16.
Put a new packing (6) in the groove of the nut (7).
17.
Coat the lip of the seal (8), packing (6), and threads of nut (7) with the same oil used in the transmission.
18.
Hold the sleeve (9) with the holding fixture (T101447) and install the nut (7).
19.
Use the wrench (T101449) to torque the nut (7) 150 to 200 foot-pounds (203 to 271 Nm).
20.
Secure the nut (7) to the sleeve (9) with lockwire (C-405). Check the pinion (12) for free rotation.
412-A-63-10-00-19A-710A-B
Applicable to: ALL
Page 00197-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00021-A-001-01
Figure 1. Generator (or SYS 2 Hydraulic Pump) Drive Quill (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-19A-710A-B
ECCN EAR99
31 MAY 2023 Page 00197-3
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-19A-710A-B
Applicable to: ALL
Page 00197-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Offset Accessory Drive Quill (212-040-208-003 and -101) - Disassembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Spanner Wrench
Wrench Assembly
Wrench Assembly
Plate Assembly
AN8516-1
T101305
T101568
T101589
1
1
1
1
Remarks
Procedure
1.
Clamp the wrench assembly (T101568) in a vise with the spline end up.
2.
Put the quill on the wrench assembly (T101568) with the pinion (15, Figure 1) teeth down, engaging the splines of the
pinion with the wrench.
3.
Bend the locking tangs of the lockwasher (7) out of the recess in the nut (8).
4.
Hold the sleeve (6) and remove the nut (8) with the spanner wrench (AN8516-1).
5.
Remove the lockwasher (7).
6.
Remove the retainer (2) from the gear (1) and the support (3). Remove the gear from support.
7.
Remove the quill from the wrench assembly (T101568) and place the quill on a press.
8.
Press the support (3) out of the bearing (5). Remove the retaining ring (4) from the sleeve (6).
9.
Put the quill on the wrench assembly (T101568) with the pinion (15) teeth down, engaging the splines of the
pinion with the wrench.
10.
Remove the clip (9).
11.
Remove the nut (10) with the wrench assembly (T101305).
12.
Remove the retaining ring (14) from the slot with a small screwdriver.
13.
Remove the quill from the wrench assembly (T101568).
14.
Heat the sleeve (6) with a heat lamp.
15.
Press the pinion (15) and the bearing stack out of the sleeve (6).
16.
Press the bearing (5) out of the sleeve (6). Discard the bearing.
17.
Install the plate assembly (T101589) on the pinion between the spacer (12) and the duplex bearing (11).
18.
Press the pinion (15) out of the duplex bearing (11) using a suitable pressing plug.
19.
Remove the spacer (12), roller bearing (13), and retaining ring (14) from the pinion (15).
Applicable to: ALL
412-A-63-10-00-20A-530A-B
ECCN EAR99
31 MAY 2023 Page 00198-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00025-A-001-01
Figure 1. Offset Accessory Drive Quill (Sheet 1 of 1)
412-A-63-10-00-20A-530A-B
Applicable to: ALL
Page 00198-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Offset Accessory Drive Quill (212-040-208-003 and -101) - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Corrosion preventive compound
Drycleaning solvent
MEK
Solvent
Clean cloth
C-105
C-304
C-309
C-334
C-516
AR
AR
AR
AR
AR
Remarks
Procedure
1.
Clean all the quill parts with drycleaning solvent (C-304). Use a soft bristle brush to dislodge stubborn deposits.
2.
All parts except the bearings may be cleaned with solvent (C-334) by vapor degreasing.
3.
Remove the sealant from the sleeve with a plastic scraper and MEK (C-309).
DO NOT ALLOW BEARINGS TO SPIN WHILE DRYING.
4.
Dry the parts with a clean cloth (C-516) or dry filtered compressed air.
DO NOT HANDLE UNOILED BEARINGS WITH BARE HANDS.
NOTE
Parts treated per the following step may be left covered in indoor storage for approximately 150 hours
without being affected by corrosion.
5.
Coat the bearings with corrosion preventive compound (C-105) immediately after cleaning (BHT-ALL-SPM, Standard
Practices Manual).
Applicable to: ALL
412-A-63-10-00-20A-258A-B
ECCN EAR99
31 MAY 2023 Page 00199-1
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-20A-258A-B
Applicable to: ALL
Page 00199-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Offset Accessory Drive Quill (212-040-208-003 and -101) - Inspection
Procedure
NOTE
Wear limits are provided to show required fit between mating parts. It is not intended that all dimensions
be checked as a prescribed overhaul procedure, however, parts that show evidence of wear or physical
damage must be checked dimensionally.
1.
Inspect the quill for corrosion damage to the threaded studs and the stud holes.
2.
Inspect the worn or damaged parts dimensionally in accordance with Figure 1.
3.
Inspect the gear (1, Figure 2) and pinion (15) for spalled, scuffed, pitted, chipped, or dented teeth.
4.
Inspect the roller bearing (13) surface of the pinion for spalling, scoring, pitting, brinelling, and corrosion damage.
5.
Inspect the splines on the pinion (15) for chipped, pitted, or excessively worn teeth.
6.
Inspect the pinion (15) for damaged threads.
7.
Inspect the wear pattern on the gear (1), as shown in Figure 3.
8.
Inspect the bearings (11 and 13, Figure 2) for spalling, scoring, pitting, brinelling, corrosion damage, and for cracked
or broken retainers.
9.
Inspect the roller bearing (13) for roughness when rotated.
10.
Inspect the sleeve (6) for corrosion damage and loose or damaged bearing liners.
11.
Inspect the support (3), nut (8), and nut (10) for damaged threads.
12.
Inspect the following parts by magnetic particle inspection (Code M) or fluorescent penetrant inspection (Code
F), as applicable. Demagnetize the parts after the magnetic particle inspection. Refer to Table 2 and the
BHT-ALL-SPM, Standard Practices Manual for the procedure.
Figure 2INDEX NUMBER
NOMENCLATURE
CODE
1
Gear
M
3
Support
M
6
Sleeve
F
8
Nut
M
10
Nut
M
15
Pinion
M
Table 2. Magnetic Particle Inspection
PART NUMBER
NOMENCLATURE
ITEM AND FIGURE
SET UP AND MAGNETIZATION CURRENT REQUIREMENTS
HP/EP OFFSET ACCESSORY DRIVE QUILL (212-040-208-101)
212-040-201-101
Gear
1, Figure 2
SET UP:
Place part over a 2.0-inches (51-mm) diameter central conductor.
Current for primary diameters, magnetize at 2170 amps.
Omit coil shot.
204-040-252-001
Nut
8, Figure 2
SET UP:
Applicable to: ALL
412-A-63-10-00-20A-280A-B
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31 MAY 2023 Page 00200-1
BHT-412-CRO
Table 2. Magnetic Particle Inspection (continued)
Place part over a 2.0-inches (51-mm) diameter central conductor.
Current for primary diameters, magnetize at 1570 amps.
Omit coil shot.
204-040-412-001
Nut
10, Figure 2
SET UP:
Place part over a 1.0-inch (25-mm) diameter central conductor.
Current for primary diameters, magnetize at 972 amps.
Omit coil shot.
212-040-202-101
Pinion
15, Figure 2
SET UP:
Place part over a 1.0-inch (25-mm) diameter central conductor.
Current for primary diameters, magnetize at 2920 amps.
Optional current for secondary diameters, magnetize at 1090 amps.
Omit coil shot.
212-040-207-001
Spacer
12, Figure 2
SET UP:
Place part over a 2-inches (51-mm) diameter central conductor.
Current for primary diameters, magnetize at 1250 amps.
Omit coil shot.
OFFSET ACCESSORY DRIVE QUILL (212-040-208-001)
204-040-252-001
Nut
8, Figure 2
SET UP:
Place part over a 2-inches (51-mm) diameter central conductor.
Current for primary diameters, magnetize at 1570 amps.
Omit coil shot.
204-040-412-001
Nut
10, Figure 2
SET UP:
Place part over a 1.0-inch (25-mm) diameter central conductor.
Current for primary diameters, magnetize at 972 amps.
Omit coil shot.
212-040-201-001
Gear
1, Figure 2
SET UP:
Place part over a 2-inches (51-mm) diameter central conductor.
Current for primary diameters, magnetize at 2170 amps.
412-A-63-10-00-20A-280A-B
Applicable to: ALL
Page 00200-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Table 2. Magnetic Particle Inspection (continued)
Omit coil shot.
212-040-202-001
Pinion
15, Figure 2
SET UP:
Place part over a 1.0-inch (25-mm) diameter central conductor.
Current for primary diameters, magnetize at 2920 amps.
Optional current for secondary diameters, magnetize at 1090 amps.
Omit coil shot.
212-040-207-001
Spacer
12, Figure 2
SET UP:
Place part over a 2-inches (51-mm) diameter central conductor.
Current for primary diameters, magnetize at 1250 amps.
Omit coil shot.
NOTES:
1. Magnetization currents provided are applicable to magnetic particle inspection apparatus using Direct Current (DC) . If an
Alternating Current (AC) apparatus is used, adjust the current as follows: AC= 0.667 x DC.
2. Ferrous parts requiring magnetic particle inspection that are not addressed in the attached material, are to be inspected in
accordance with the general procedures outlined in ASTM E1444 standard practices (BHT-ALL-SPM, Chapter 6, Standard
Practices Manual).
3. Part numbers listed apply to all successive dash numbers for that component unless otherwise specified.
Applicable to: ALL
412-A-63-10-00-20A-280A-B
ECCN EAR99
31 MAY 2023 Page 00200-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00208-A-001-01
Figure 1. Offset Accessory Drive Quill - Wear Limits (Sheet 1 of 1)
412-A-63-10-00-20A-280A-B
Applicable to: ALL
Page 00200-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00025-A-001-01
Figure 2. Offset Accessory Drive Quill (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-20A-280A-B
ECCN EAR99
31 MAY 2023 Page 00200-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00209-A-001-01
Figure 3. Offset Accessory Drive Quill Gear - Wear Pattern (Sheet 1 of 1)
412-A-63-10-00-20A-280A-B
Applicable to: ALL
Page 00200-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Offset Accessory Drive Quill (212-040-208-003 and -101) - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Chemical film material
Chromic acid treatment
Cadmium plating solution
Dichromate treatment
Chromic acid
India stone
C-100
C-103
C-108
C-114
C-116
C-464
AR
AR
AR
AR
AR
AR
Remarks
Procedure
1.
Replace the parts that are not within the allowable wear limits (Figure 1).
REPLACE BEARINGS AS A MATCHED SET.
2.
Replace the duplex bearings as a matched serialized set, if unserviceable.
3.
Replace the parts that are cracked, broken, warped, have malformed threads, or exceed wear limits.
4.
Repair dents and nicks or the sleeve flange top surface by polishing with a fine india stone (C-464). Blend the
repaired area into the flat surface with a minimum radius of 0.12 inch (3.0 mm). The finished repair must be 63
Roughness Height Rating (RHR) or better. The maximum depth, after repair, must not exceed 0.030 inch (0.76 mm).
5.
Refinish the parts after repair as follows (BHT-ALL-SPM, Standard Practices Manual):
5.1.
Aluminum parts: touch up with chemical film material (C-100).
5.2.
Magnesium parts: remove all traces of corrosion by immersion in chromic acid (C-116). Touch up parts with chromic
acid treatment (C-103) or treat the entire part with dichromate treatment (C-114).
5.3.
Cadmium plated steel parts: treat rework areas with cadmium plating solution (C-108).
Applicable to: ALL
412-A-63-10-00-20A-685A-B
ECCN EAR99
31 MAY 2023 Page 00201-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00208-A-001-01
Figure 1. Offset Accessory Drive Quill - Wear Limits (Sheet 1 of 1)
412-A-63-10-00-20A-685A-B
Applicable to: ALL
Page 00201-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Offset Accessory Drive Quill (212-040-208-003 and -101) - Assembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Spanner Wrench
Wrench Assembly
Wrench Assembly
AN8516-1
T101305
T101568
1
1
1
Remarks
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Drycleaning solvent
C-304
AR
Remarks
Procedure
1.
Clean all the parts with drycleaning solvent (C-304) and drain.
2.
Coat all the parts with the same oil used in the transmission and drain.
DO NOT HANDLE UNOILED PARTS WITH BARE HANDS.
3.
Heat the sleeve (6, Figure 1) with a heat lamp. Put the sleeve on the press with the face up. Press the new bearing
(5) into the sleeve with the face of the bearing up. Install the retaining ring (4).
DUPLEX BEARING MUST BE A MATCHED SET WITH SAME SERIAL NUMBER ON BOTH
BEARINGS.
4.
Press the duplex bearing (11) into the sleeve (6) with the two bearings of the set positioned back-to-back.
5.
Install the spacer (12) with the larger diameter end up.
6.
Press the roller bearing (13) into the sleeve (6).
NOTE
To help the removal, install the end of the retaining ring (14) in the middle of the slot.
7.
Install the retaining ring (14).
8.
Support the inner race of the bearing (5) with a suitable sleeve and press the support (3) into the bearing.
9.
Heat the inner race of the duplex bearing (11) with a heat lamp.
10.
Support the duplex bearing (11) on the inner race and press the pinion (15) into the sleeve (6).
11.
Place the wrench assembly (T101568) in a vise, splined end up. Put the sleeve (6) and the pinion (15) on the
wrench assembly with pinion teeth down.
12.
Install the nut (10) on the pinion (15), torque the nut 30 to 40 foot-pounds (41 to 54 Nm) with the wrench assembly
(T101305). Safety the nut with the clip (9).
13.
Place the gear (1) on the support (3) and install the retainer (2). Make sure that both ends of the retainer are fully
engaged in the holes in the tang of the gear.
14.
Install the lockwasher (7) on the support (3) with the tangs engaged in the slots of the support.
Applicable to: ALL
412-A-63-10-00-20A-710A-B
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BHT-412-CRO
15.
Install the nut (8) with the beveled side next to the lockwasher (7). With the spanner wrench (AN8516-1), torque the
nut 50 to 100 foot-pounds (68 to 136 Nm) with the two tangs of the lockwasher aligned with the slots of the nut. Bend
the tangs of the lockwasher into the slots of the nut.
16.
Remove the offset accessory drive quill from the wrench assembly.
17.
Check the pinion and the bearings for free rotation.
412-A-63-10-00-20A-710A-B
Applicable to: ALL
Page 00202-2 31 MAY 2023
ECCN EAR99
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ICN-412-A-631000-B-97499-00025-A-001-01
Figure 1. Offset Accessory Drive Quill (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-20A-710A-B
ECCN EAR99
31 MAY 2023 Page 00202-3
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-20A-710A-B
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Page 00202-4 31 MAY 2023
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BHT-412-CRO
Accessory and Tail Rotor Drive and Sump Assembly (212-040-365-105, -109, and -111)
- Disassembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Screw Set
Jackscrew Set
T101308
T101338
1
1
Remarks
Procedure
NOTE
If the records or the physical appearance of the accessory and tail rotor drive and sump assembly
indicates the assembly was subject to an accident or incident outside the realm of normal usage, perform
a conditional inspection (412-A-63-10-00-21A-284A-B / 00205).
NOTE
If the accessory and tail rotor drive and sump assembly is being disassembled for replacement of parts,
instead of an overhaul, disassemble only to the extent necessary to replace the parts.
1.
Remove the rotary oil pump (24, Figure 1) as follows:
1.1.
Loosen the nuts (39A and 39B) and remove the tube assemblies (30 and 34), nut (29), aluminum washer (28), tee
(33), drain valve (63), union (69), and attached fittings.
1.2.
Remove the nuts (27 and 37), washers (26, 38, and 39), and bracket (25).
1.3.
Remove the set screw (24A).
1.4.
Install a slide hammer in the threaded hole in the center of the rotary oil pump (24). Make sure that the slide hammer
fully engages in the threads of the rotary oil pump but does not bottom out in the threaded hole.
1.5.
Remove the rotary oil pump (24) with the slide hammer.
1.6.
Remove and discard the packings (23).
2.
Disassemble the rotary oil pump (24) (412-A-63-10-00-22A-530A-B / 00209).
3.
Remove the hydraulic drive quill (46) as follows:
3.1.
Remove the four nuts (40) and the washers (41).
3.2.
Remove the two nuts (44) and the aluminum washers (45).
3.3.
Cut the sealant around the edge of the hydraulic drive quill (46), where it contacts the accessory and tail rotor drive
case (22), with a plastic scraper. Remove the sealant from the three threaded holes in the quill. Install the screw set
(T101308). Equally turn the jackscrews clockwise and pull the quill from the case.
3.4.
Remove and discard the packing (47).
4.
Disassemble the hydraulic drive quill (46) (412-A-63-10-00-28A-530A-B / 00239).
5.
Remove the accessory and tail rotor drive quill (10) as follows:
5.1.
Cut and remove the lockwire.
5.2.
Remove the six nuts (11) and steel washers (12).
5.3.
Install the jackscrew set (T101338) in the accessory and tail rotor drive quill (10). Equally turn the jackscrews
clockwise to pull the quill from accessory and tail rotor drive case (22).
5.4.
Remove the retaining ring (9).
5.5.
Remove the oil pump shaft (14) and the retaining ring (13).
Applicable to: ALL
412-A-63-10-00-21A-530A-B
ECCN EAR99
31 MAY 2023 Page 00203-1
BHT-412-CRO
6.
Disassemble the accessory and tail rotor drive quill (10) (412-A-63-10-00-25A-530A-B / 00224).
7.
Remove the tail rotor drive quill (16) as follows:
7.1.
Remove the six nuts (21), washers (17, 18, and 20), and spacer (19).
7.2.
Cut the sealant around the edge of the tail rotor drive quill (16), where it contacts the accessory and tail rotor drive
case (22), with a plastic scraper. Remove the sealant from the three threaded holes in the quill. Install the jackscrew
set (T101338). Equally turn the jackscrews clockwise and pull the quill from the case.
7.3.
Remove and discard the packing (15).
8.
Disassemble the tail rotor drive quill (16) (412-A-63-10-00-26A-530A-B / 00229 or 412-A-63-10-00-27A-530A-B /
00234).
9.
Remove the nut (60), packing (61), and elbow (59). Discard the packing.
10.
Remove the screw (58), packings (52 and 53), and jet No. 4 (54). Discard the packings.
11.
Remove the screw (57), thin steel washer (56), and seal (55). Discard the seal.
12.
Remove the plug (86) and the packing (85). Discard the packing.
13.
Remove the electrical chip detector element (71) and the packings (72 and 73). Discard the packings.
14.
Remove the electrical chip detector self-closing valve (74) and the gasket (75). Discard the gasket.
15.
Remove the pump screen (88) and the gasket (87). Discard the gasket.
16.
Remove the retaining ring (76), packing (77), glass (78), and oil level indicator (79). Discard the packing.
17.
Remove the retaining ring (80), packing (81), glass (82), and oil level indicator (83). Discard the packing.
18.
Remove the nut (1), thin steel washer (2), and bracket (3).
19.
Remove the three nuts (6), thin steel washers (7), and bracket (8).
20.
Remove the oil filter (4) or the full flow debris monitor (4A), as applicable.
21.
Remove and discard the packing (5).
22.
Disassemble the oil filter (4) (412-A-63-10-00-23A-530A-B / 00214) or the full flow debris monitor (4A)
(412-A-63-10-00-24A-530A-B / 00219), as applicable.
THE SHIM PLATES (2, 6, AND 9, Figure 2) MUST BE INSTALLED IN THE SAME LOCATION ON
SAME THE CASE OR GEAR BACKLASH WILL BE AFFECTED.
23.
Remove the shim plates (2, 6, and 9) as follows:
23.1.
Remove the three screws (1) and the shim plate (2). Mark the shim plate for installation at the same location.
23.2.
Remove the three screws (5) and the shim plate (6). Mark the shim plate for installation at the same location.
23.3.
Remove the three screws (10) and the shim plate (9). Mark the shim plate for installation at the same location.
412-A-63-10-00-21A-530A-B
Applicable to: ALL
Page 00203-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00029-A-001-01
Figure 1. Accessory and Tail Rotor Drive and Sump Assembly (Sheet 1 of 4)
Applicable to: ALL
412-A-63-10-00-21A-530A-B
ECCN EAR99
31 MAY 2023 Page 00203-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00030-A-001-01
Figure 1. Accessory and Tail Rotor Drive and Sump Assembly (Sheet 2 of 4)
412-A-63-10-00-21A-530A-B
Applicable to: ALL
Page 00203-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00031-A-001-01
Figure 1. Accessory and Tail Rotor Drive and Sump Assembly (Sheet 3 of 4)
Applicable to: ALL
412-A-63-10-00-21A-530A-B
ECCN EAR99
31 MAY 2023 Page 00203-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00032-A-001-01
Figure 1. Accessory and Tail Rotor Drive and Sump Assembly (Sheet 4 of 4)
412-A-63-10-00-21A-530A-B
Applicable to: ALL
Page 00203-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00210-A-001-01
Figure 2. Accessory and Tail Rotor Drive Case Assembly (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-21A-530A-B
ECCN EAR99
31 MAY 2023 Page 00203-7
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-21A-530A-B
Applicable to: ALL
Page 00203-8 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Accessory and Tail Rotor Drive and Sump Assembly (212-040-365-105, -109, and -111) Cleaning - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Drycleaning solvent
MEK
Solvent
Paint remover
Clean cloth
C-304
C-309
C-334
C-436
C-516
AR
AR
AR
AR
AR
Remarks
Procedure
NOTE
Instructions for cleaning the following parts are located in the indicated paragraphs.
Oil filter (412-A-63-10-00-23A-258A-B / 00215), or full flow debris monitor (412-A-63-10-00-24A-258A-B
/ 00220).
Rotary oil pump (412-A-63-10-00-22A-258A-B / 00210).
Accessory and tail rotor drive quill (412-A-63-10-00-25A-258A-B / 00225).
Hydraulic drive quill (412-A-63-10-00-28A-258A-B / 00240).
Tail rotor drive quill (412-A-63-10-00-26A-258A-B / 00230 or 412-A-63-10-00-27A-258A-B / 00235).
1.
Clean the parts illustrated in Figure 1, except the parts listed in the preceding note, with drycleaning solvent (C-304).
Dislodge stubborn deposits with a soft bristle brush. All parts except the bearings may be cleaned with solvent
(C-334) by vapor degreasing method if vapor degreasing equipment is available.
2.
Clean sealant from the case adjacent to the quill ports with a plastic scraper and a clean cloth (C-516) moistened
with MEK (C-309).
3.
Remove the paint from all the painted parts with paint remover (C-436).
Applicable to: ALL
412-A-63-10-00-21A-258A-B
ECCN EAR99
31 MAY 2023 Page 00204-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00029-A-001-01
Figure 1. Accessory and Tail Rotor Drive and Sump Assembly (Sheet 1 of 4)
412-A-63-10-00-21A-258A-B
Applicable to: ALL
Page 00204-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00030-A-001-01
Figure 1. Accessory and Tail Rotor Drive and Sump Assembly (Sheet 2 of 4)
Applicable to: ALL
412-A-63-10-00-21A-258A-B
ECCN EAR99
31 MAY 2023 Page 00204-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00031-A-001-01
Figure 1. Accessory and Tail Rotor Drive and Sump Assembly (Sheet 3 of 4)
412-A-63-10-00-21A-258A-B
Applicable to: ALL
Page 00204-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00032-A-001-01
Figure 1. Accessory and Tail Rotor Drive and Sump Assembly (Sheet 4 of 4)
Applicable to: ALL
412-A-63-10-00-21A-258A-B
ECCN EAR99
31 MAY 2023 Page 00204-5
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-21A-258A-B
Applicable to: ALL
Page 00204-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Accessory and Tail Rotor Drive and Sump Assembly (212-040-365-105, -109, and -111) Conditional Inspection
Procedure
1.
Refer to the BHT-412-MM, conditional inspection section, for the definition of accidents or incidents that require a
conditional inspection of the accessory and tail rotor drive and sump components. Inspection procedures and damage
limits are also included in the conditional inspections section.
Applicable to: ALL
412-A-63-10-00-21A-284A-B
ECCN EAR99
31 MAY 2023 Page 00205-1
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-21A-284A-B
Applicable to: ALL
Page 00205-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Accessory and Tail Rotor Drive and Sump Assembly (212-040-365-105, -109, and -111) - Normal
Inspection
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Drycleaning solvent
India stone
C-304
C-464
AR
AR
Remarks
Procedure
NOTE
Instructions for inspecting the following parts are located in the indicated paragraphs.
Oil filter (412-A-63-10-00-23A-280A-B / 00216), or full flow debris monitor (412-A-63-10-00-24A-280A-B
/ 00221).
Rotary oil pump (412-A-63-10-00-22A-280A-B / 00211).
Accessory and tail rotor drive quill (412-A-63-10-00-25A-280A-B / 00226).
Hydraulic drive quill (412-A-63-10-00-28A-280A-B / 00241).
Tail rotor drive quill (412-A-63-10-00-26A-280A-B / 00231 or 412-A-63-10-00-27A-280A-B / 00236).
1.
Inspect the following parts by magnetic particle inspection (Code M) or fluorescent penetrant inspection (Code
F), as applicable. Demagnetize the parts after the magnetic particle inspection. Refer to Table 2 and the
BHT-ALL-SPM, Standard Practices Manual for the procedure.
Figure 1INDEX NO.
NOMENCLATURE
CODE
14
Oil Pump Shaft
M
22
Accessory and Tail Rotor Drive Case
F
Table 2. Magnetic Particle Inspection
PART NUMBER
NOMENCLATURE
ITEM AND FIGURE
SET UP AND MAGNETIZATION CURRENT REQUIREMENTS
212-040-197-001
Oil Pump Shaft
14, Figure 1
SET UP:
Place part over a 0.344-inch diameter central conductor.
Current for primary diameters, magnetize at 856 amps.
Optional current for secondary diameters, magnetize at 367 amps.
CENTRAL CONDUCTOR MAY GET HOT.
SET UP: 5 TURN COIL SHOT:
Hold part in bottom of coil with axis parallel to coil axis.
Magnetize at 1120 amps.
NOTES:
1. Magnetization currents provided are applicable to magnetic particle inspection apparatus using Direct Current (DC) . If an
Alternating Current (AC) apparatus is used, adjust the current as follows: AC= 0.667 x DC.
Applicable to: ALL
412-A-63-10-00-21A-280A-B
ECCN EAR99
31 MAY 2023 Page 00206-1
BHT-412-CRO
Table 2. Magnetic Particle Inspection (continued)
2. Ferrous parts requiring magnetic particle inspection that are not addressed in the attached material, are to be inspected in
accordance with the general procedures outlined in ASTM E1444 standard practices (BHT-ALL-SPM, Chapter 6, Standard
Practices Manual).
3. Part numbers listed apply to all successive dash numbers for that component unless otherwise specified.
2.
Inspect the oil tube assemblies (30 and 34, Figure 1) and the bracket (25) and related fittings for mechanical and
corrosion damage. Superficial mechanical damage is permitted without repair. Cracked or distorted parts are not
permitted. Superficial corrosion is permitted if polished out and area treated for corrosion prevention.
3.
Inspect the oil pump shaft (14) for mechanical and corrosion damage. Superficial damage is permitted without
repair. Inspect the splines and gear teeth for pits, chips or excessively worn teeth. Damage that can be detected
visually is not permitted.
4.
Inspect the sight glasses (78 and 82) for discoloration and crazing. Damage that prevents reading the indicator is
not permitted.
5.
Inspect the oil level indicators (79 and 83) for discoloration and chipped paint. Damage that prevents reading the
indicator is not permitted.
6.
Inspect the accessory and tail rotor drive quill (10) for pitted, chipped, cracked, broken, and worn spline teeth.
Minor dents and nicks on the spline teeth are permitted if polished out with a fine india stone (C-464). More severe
damage is not permitted.
7.
Inspect the oil pump screen (88) for metal particles. Clean the screen with drycleaning solvent (C-304), and dry with
compressed air. Visually inspect the screen for distortion, cracks, and damaged threads. Damage that can be
visually detected is not permitted.
8.
Inspect the electric chip detector element (71) for metal particles. Inspect the element for damaged threads on
the stud and for distorted lugs. Damage that can be visually detected is not permitted. Inspect the electrical chip
detector self-closing valve (74) for damaged threads, valve spring, and ball. Damage that can be visually detected is
not permitted.
9.
Inspect the jet No. 4 (54) for distortion and cracks. Damage that can be visually detected is not permitted.
10.
Inspect the accessory and tail rotor drive case (22) in accordance with Figure 2.
NOTE
Case wear/damage limits: the case wear limits are provided to show the required fit between the parts.
It is not intended that wear be measured as a required overhaul procedure.
11.
Inspect the case parts for the input quill and tail rotor drive quill. If there is evidence of wear, measure the case, as
shown in Figure 3.
412-A-63-10-00-21A-280A-B
Applicable to: ALL
Page 00206-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00029-A-001-01
Figure 1. Accessory and Tail Rotor Drive and Sump Assembly (Sheet 1 of 4)
Applicable to: ALL
412-A-63-10-00-21A-280A-B
ECCN EAR99
31 MAY 2023 Page 00206-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00030-A-001-01
Figure 1. Accessory and Tail Rotor Drive and Sump Assembly (Sheet 2 of 4)
412-A-63-10-00-21A-280A-B
Applicable to: ALL
Page 00206-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00031-A-001-01
Figure 1. Accessory and Tail Rotor Drive and Sump Assembly (Sheet 3 of 4)
Applicable to: ALL
412-A-63-10-00-21A-280A-B
ECCN EAR99
31 MAY 2023 Page 00206-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00032-A-001-01
Figure 1. Accessory and Tail Rotor Drive and Sump Assembly (Sheet 4 of 4)
412-A-63-10-00-21A-280A-B
Applicable to: ALL
Page 00206-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00211-A-001-01
Figure 2. Accessory and Tail Rotor Drive Case Assembly - Damage Limits (Sheet 1 of 2)
Applicable to: ALL
412-A-63-10-00-21A-280A-B
ECCN EAR99
31 MAY 2023 Page 00206-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00212-A-001-01
Figure 2. Accessory and Tail Rotor Drive Case Assembly - Damage Limits (Sheet 2 of 2)
412-A-63-10-00-21A-280A-B
Applicable to: ALL
Page 00206-8 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00213-A-001-01
Figure 3. Accessory and Tail Rotor Drive and Sump Assembly - Damage Limits (Sheet 1 of 3)
Applicable to: ALL
412-A-63-10-00-21A-280A-B
ECCN EAR99
31 MAY 2023 Page 00206-9
BHT-412-CRO
ICN-412-A-631000-B-97499-00214-A-001-01
Figure 3. Accessory and Tail Rotor Drive and Sump Assembly - Damage Limits (Sheet 2 of 3)
412-A-63-10-00-21A-280A-B
Applicable to: ALL
Page 00206-10 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-01212-A-001-01
Figure 3. Accessory and Tail Rotor Drive and Sump Assembly - Damage Limits (Sheet 3 of 3)
Applicable to: ALL
412-A-63-10-00-21A-280A-B
ECCN EAR99
31 MAY 2023 Page 00206-11
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-21A-280A-B
Applicable to: ALL
Page 00206-12 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Accessory and Tail Rotor Drive and Sump Assembly (212-040-365-105, -109, and -111) - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Chromic acid treatment
Drycleaning solvent
Sealant
Cleaning compound
India stone
Clean cloth
C-103
C-304
C-308
C-318
C-464
C-516
AR
AR
AR
AR
AR
AR
Remarks
Procedure
1.
Repair the case with corrosion damage around the studs as follows:
1.1.
Refer to Figure 1 for repairable damage limits.
1.2.
With a 0.327 to 0.334 inch (8.31 to 8.48 mm) in diameter drill, counterdrill stud holes to a maximum depth of 0.125
inch (3.18 mm). Break all sharp edges, except in the threaded area.
1.3.
Treat drilled areas of the case with chromic acid treatment (C-103) (BHT-ALL-SPM, Standard Practices Manual).
1.4.
Install a new stud in the reworked hole. Refer to the BHT-ALL-SPM, Standard Practices Manual for the procedure.
1.5.
Fill the counterdrilled holes with sealant (C-308).
2.
Remove the threaded insert (12) that failed to pass inspection and install a new insert (BHT-ALL-SPM, Standard
Practices Manual).
3.
Rework the chip detector boss as follows:
3.1.
Install the sump case in a suitable machine tool such as a vertical milling machine. Use minimal clamping forces
on the sump case. With a dial indicator mounted in the machined spindle, sweep the face of the sump case chip
detector boss. Adjust the position of sump case as required so that the total indicator runout is no greater than
0.002 inch (0.05 mm).
3.2.
Machine the chip detector boss surface to achieve 1.130 to 1.110 inches (28.70 to 28.19 mm) entry-countersink
diameter. The machining depth shall not exceed 0.035 inch (0.89 mm). Refer to Table 1 for the required depth
of machining to achieve 1.130 to 1.110 inches (28.70 to 28.19 mm) entry countersink. The surface finish of the
remachined boss face must not exceed 63 RMS.
3.3.
Remove oil and grease with drycleaning solvent (C-304). Clean the freshly machined face with cleaning compound
(C-318) mixed with water, to ensure a water- break free surface. Rinse with water and repeat as necessary to provide
a clean surface. Allow the surface to air-dry or force dry with clean, filtered compressed air and a clean cloth (C-516).
3.4.
Treat the reworked areas and other areas on the case where chemical film has been removed with chromic acid
brush-on treatment (BHT-ALL-SPM, Standard Practices Manual).
Table 1. Chip Detector Boss Measurements and Machining Requirements
COUNTERSINK DIAMETER MEASUREMENTS
INCHES (MM)
MACHINING DEPTH REQUIRED INCH (MM)
1.230 (31.2420)
0.035/0.030 (0.8890/0.7620)
1.220 (30.9880)
0.032/0.027 (0.8128/0.6858)
1.210 (30.7340)
0.029/0.024 (0.7366/0.6096)
1.200 (30.4800)
0.026/0.021 (0.6604/0.5334)
1.190 (30.2260)
0.023/0.018 (0.5842/0.4572)
1.180 (29.9720)
0.020/0.015 (0.5080/0.3810)
1.170 (29.7180)
0.017/0.012 (0.4318/0.3048)
Applicable to: ALL
412-A-63-10-00-21A-685A-B
ECCN EAR99
31 MAY 2023 Page 00207-1
BHT-412-CRO
Table 1. Chip Detector Boss Measurements and Machining Requirements (continued)
COUNTERSINK DIAMETER MEASUREMENTS
INCHES (MM)
MACHINING DEPTH REQUIRED INCH (MM)
1.160 (29.4640)
0.014/0.009 (0.3556/0.2286)
1.150 (29.2100)
0.011/0.006 (0.2794/0.1524)
1.140 (29.9560)
0.008/0.003 (0.2032/0.0762)
412-A-63-10-00-21A-685A-B
Applicable to: ALL
Page 00207-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00211-A-001-01
Figure 1. Accessory and Tail Rotor Drive Case Assembly - Damage Limits (Sheet 1 of 2)
Applicable to: ALL
412-A-63-10-00-21A-685A-B
ECCN EAR99
31 MAY 2023 Page 00207-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00212-A-001-01
Figure 1. Accessory and Tail Rotor Drive Case Assembly - Damage Limits (Sheet 2 of 2)
412-A-63-10-00-21A-685A-B
Applicable to: ALL
Page 00207-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Accessory and Tail Rotor Drive and Sump Assembly (212-040-365-105, -109, and -111) Assembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Backlash Tool
212-040-001-3 GIF-1
1
Remarks
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Chemical film material
Sealant
Sealant
Lockwire
C-100
C-308
C-328
C-405
AR
AR
AR
AR
Remarks
Procedure
1.
Inspect the accessory and tail rotor drive case (4, Figure 1) to make sure that it is clean and that the oil passages are
not obstructed. Put the case on a clean workbench or install in a suitable support fixture.
2.
Install the shim plates (2, 6, and 9) as follows:
THE SHIM PLATES (2, 6, AND 9) MUST BE INSTALLED IN THE SAME LOCATION ON THE SAME
CASE FROM WHICH REMOVED OR GEAR BACKLASH WILL PROBABLY BE INCORRECT.
2.1.
Inspect the accessory and tail rotor drive case (4) and the shim plate (2) for the serial number. If the same serial
number is legible on both parts, or if the shim plate was indexed at the time of removal, install the shim plate as
outlined in Step 2.2.. If the shim plate cannot be positively identified, determine the required shim thickness
as outlined in Step 2.3..
2.2.
Put a shim plate (2) of the correct thickness on the accessory and tail rotor drive case (4) and install the three
screws (1).
2.3.
Determine the required thickness for the shim plate (2) for the accessory and tail rotor drive case (4) as follows:
2.3.1.
Inspect the accessory and tail rotor drive case (4) for the reference dimension, which should be metal stamped or
vibro-etched on the case adjacent to the mounting surface for the shim plate (2). Record this dimension and location
on the case.
2.3.2.
Measure the thickness of the shim plate (2) and record.
2.3.3.
Add the shim plate thickness recorded in Step 2.3.2. to the reference dimension recorded in Step 2.3.1.. The
resulting value must fall within the minimum/maximum dimensions listed as follows. This is the required value
for a plated shim plate.
SHIM
MINIMUM INCH (MM)
MAXIMUM INCH (MM)
Shim Plate (6), Accessory and Tail
Rotor Drive Quill
4.7895 (121.6533)
4.7900 (121.6660)
Shim Plate (9), Tail Rotor Drive Quill
4.8685 (123.6599)
4.8690 (123.6726)
Shim Plate (2), Hydraulic Drive Quill
4.8685 (123.6599)
4.8690 (123.6726)
2.4.
Procure a shim plate (2) of the correct dimension determined in Step 2.3.. Install the shim as described in Step 2.2..
2.5.
Install the shim plates (6 and 9) by the same procedure outlined in Step 2.1. through Step 2.4..
3.
Assemble the accessory and tail rotor drive quill (10, Figure 2) (412-A-63-10-00-25A-710A-B / 00228).
Applicable to: ALL
412-A-63-10-00-21A-710A-B
ECCN EAR99
31 MAY 2023 Page 00208-1
BHT-412-CRO
4.
Install the accessory and tail rotor drive quill (10) as follows:
4.1.
Make sure that correct shim plate is installed on the accessory and tail rotor drive quill (10).
4.2.
Install the retaining ring (13) in the accessory and tail rotor drive quill (10).
4.3.
Put the oil pump shaft (14) in the quill and install the retaining ring (9).
4.4.
Heat the accessory and tail rotor drive case (22) at the port for the accessory and tail rotor drive quill (10) with a
heat lamp.
4.5.
Coat the mating surfaces of the quill with the same oil used in the transmission. Put the quill in the case and install
the six steel washers (12) and the nuts (11). Torque the nuts 50 to 70 inch-pounds (5.65 to 7.91 Nm). Secure the
nuts in pairs with lockwire (C-405).
5.
Assemble the rotary oil pump (24) (412-A-63-10-00-22A-710A-B / 00213).
6.
Install the rotary oil pump (24) as follows:
6.1.
Heat the accessory and tail rotor drive case (22) at the port for the rotary oil pump (24) with a heat lamp.
6.2.
Lubricate the new packings (23) with the same oil used in the transmission and install the packings on the rotary oil
pump (24).
DO NOT APPLY EXCESSIVE FORCE ON THE OIL PUMP OR THE RETAINING RING MAY BE
DISPLACED.
6.3.
Coat the mating surfaces of the pump and the case with the same oil used in the transmission. Put the pump in the
case and engage the oil pump shaft (14) on the pump driveshaft.
6.4.
Put the bracket (25) on the stud, at the position illustrated, and install the thin steel washer (26) and the nut (27).Install
the thin aluminum washers (39), thin steel washers (38), and nuts (37) on the two remaining studs. Torque the nuts
(27 and 37) 50 to 70 inch-pounds (5.65 to 7.91 Nm).
6.5.
Place a small quantity of chemical film material (C-100) in the hole center of the rotary oil pump (24). Insert the set
screw (24A) until it bottoms out, then apply a bead of sealant (C-308) around the outside diameter of the set screw.
7.
Assemble the tail rotor drive quill (16) (412-A-63-10-00-26A-710A-B / 00233 or 412-A-63-10-00-27A-710A-B / 00238).
8.
Install the tail rotor drive quill (16) as follows:
8.1.
Make sure that the correct shim plate is installed on the tail rotor drive quill (16).
8.2.
Heat the accessory and tail rotor drive case (22) at the port for the tail rotor drive quill (16) with a heat lamp.
8.3.
Lubricate the new packing (15) with the same oil used in the transmission and install the packing on the tail rotor
drive quill (16).
8.4.
Coat the mating surfaces of the quill and the case with the same oil used in the transmission. Carefully install the tail
rotor drive quill (16) in the case. Rotate the quill coupling if necessary to engage the gear teeth and the accessory
and tail rotor drive quill (10).
8.5.
Install the aluminum washers (17) next to the tail rotor drive quill (16). Install the thin steel washers (18), spacers (19),
thin steel washer (20), and nuts (21). Torque the nuts 50 to 70 inch-pounds (5.65 to 7.91 Nm).
9.
Assemble the hydraulic drive quill (46) (412-A-63-10-00-28A-710A-B / 00243).
10.
Install the hydraulic drive quill (46) as follows:
10.1.
Make sure that correct shim plate is installed on hydraulic drive quill (46).
10.2.
Heat the accessory and tail rotor drive case (22) at the port for the hydraulic drive quill (46) with a heat lamp.
10.3.
Remove the cover (42) and gasket (43). Discard the gasket.
10.4.
Lubricate the new packing (47) with the same oil used in the transmission and install the packing on the hydraulic
drive quill (46).
412-A-63-10-00-21A-710A-B
Applicable to: ALL
Page 00208-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
10.5.
Coat the mating surfaces of the quill and the case with the same oil used in the transmission. Carefully install the
hydraulic drive quill (46) in the case. Rotate the quill gear if necessary to engage the teeth with the accessory and
tail rotor drive quill (10).
10.6.
Install the aluminum washers (45) and the nuts (44) on the two studs.
10.7.
Torque the nuts (44) 100 to 140 inch-pounds (11.30 to 15.82 Nm).
10.8.
Check the gear backlash (Step 22.).
10.9.
Put the new gasket (43) and the cover (42) on the hydraulic drive quill (46).
10.10.
Install the four washers (41) and the nuts (40) to secure the cover (42).
10.11.
Torque the nuts (40) 100 to 140 inch-pounds (11.30 to 15.82 Nm).
11.
Lubricate the new packing (85) with the same oil used in the transmission and install the packing on the plug (86) and
install the plug in the accessory and tail rotor drive case (22). Torque the plug 300 to 400 inch-pounds (33.89 to
45.19 Nm).
12.
Wet install the pump screen (88) and the new gasket (87) with sealant (C-328). Torque the pump screen 300
to 400 inch-pounds (33.89 to 45.19 Nm).
13.
Wet install the electrical chip detector self-closing valve (74) and the new gasket (75) with sealant (C-328). Torque
the valve 300 to 400 inch-pounds (33.89 to 45.19 Nm). Install the electrical chip detector element (71) and the
new packings (72 and 73).
14.
Secure the pump screen (88) to the electrical chip detector self-closing valve (74) with lockwire (C-405). Secure the
plug (86) to the valve with lockwire (C-405).
15.
Put two new packings (52 and 53) on the jet No. 4 (54). Coat the jet and the packings with the same oil used in the
transmission. Put the jet in the accessory and tail rotor drive case (22). Install the screw (58). Install the new seal
(55), thin steel washer (56), and screw (57).Secure the screws (57 and 58) together with lockwire (C-405).
16.
Put the new packing (81) on the glass (82). Lubricate the packing and the port in the case with the same oil used in
the transmission. Install the oil level indicator (full) (83), glass (82) and retaining ring (80).
17.
Install the oil level indicator (low) (79) in the same manner outlined in Step 16..
18.
Lubricate the new packing (61) with the same oil used in the transmission and install the elbow (59), packing (61),
and nut (60).
19.
Assemble the oil filter (4) (412-A-63-10-00-23A-710A-B / 00218) or the full flow debris monitor (4A)
(412-A-63-10-00-24A-710A-B / 00223), as applicable.
20.
Install the oil filter (4) or the full flow debris monitor (4A) as follows:
20.1.
Put the assembled oil filter (4) or full flow debris monitor (4A) in the case without the packing (5) and check to ensure
the flange of the filter seats flush on the case flange. If any burrs prevent proper seating, polish out the burrs.
INSTALL FULL FLOW DEBRIS MONITOR (4A) WITH DATA PLATE ON TOP.
20.2.
Lubricate the new packing (5) with the same oil used in the transmission. Put the packing and the oil filter (4) or full
flow debris monitor (4A) on the accessory and tail rotor drive case (22).Put the bracket (8) on the filter or full flow
debris monitor at the position illustrated. Install the three thin steel washers (7) and the nuts (6).
20.3.
Put the bracket (3) on the oil filter (4) or full flow debris monitor (4A) at the position illustrated. Install the thin washer
(2) and the nut (1).
20.4.
Torque the three nuts (6) and nut (1) 50 to 70 inch-pounds (5.65 to 7.91 Nm).
21.
Install the drain valve (63) and external oil lines as follows:
21.1.
Lubricate the new packing (31) with the same oil used in the transmission and install the union (32) and the
packing in the tee (33).
Applicable to: ALL
412-A-63-10-00-21A-710A-B
ECCN EAR99
31 MAY 2023 Page 00208-3
BHT-412-CRO
21.2.
Put the tee (33) in the bracket (25) and install the aluminum washer (28) and the nut (29).
21.3.
Lubricate the new packing (36) with the same oil used in the transmission and install the packing and the union
(35) in the oil filter scupper (84).
21.4.
Install the tube assembly (34) on the union (35) and the tee (33).
INSTALL SHORT END OF UNION (69) INTO DRAIN BOSS OF ACCESSORY AND TAIL ROTOR DRIVE
CASE (22). IF LONG END OF UNION IS INSTALLED, DAMAGE TO PUMP SCREEN MAY RESULT.
21.5.
Lubricate the new packing (70) with the same oil used in the transmission and install the packing and the union (69) in
the accessory and tail rotor drive case (22).
21.6.
Lubricate the new packing (67) with the same oil used in the transmission and install the nut (68), packing, and
elbow (66) on the union (69).
21.7.
Lubricate the new packing (65) with the same oil used in the transmission and install the drain valve (63), nut (64),
and packing on the elbow (66).
21.8.
Install the tube assembly (62) on the drain valve (63) and the tee (33).
21.9.
Tighten the nuts (39A, 39B, 64, and 68).
22.
Check the backlash of the sump and accessory drive assembly quills as follows:
DO NOT ALTER SHIM PLATES ON CASE OR QUILL SLEEVE TO OBTAIN BACKLASH. IF BACKLASH
IS NOT WITHIN LIMITS, PARTS ARE IMPROPERLY ASSEMBLED OR DIMENSIONALLY INCORRECT.
REFER TO Step 2. FOR PROCEDURE TO DETERMINE CORRECT SHIM THICKNESS.
22.1.
Install the backlash tool (212-040-001-3 GIF-1) on top of the accessory drive sump (22) and attach with three bolts.
Tighten the clamp on the backlash tool to secure the pinion in the accessory and tail rotor drive quill (10, Figure 2).
22.2.
Install the backlash tool (212-040-001-3 GIF-1) (Detail 3) on the tail rotor drive quill (16). Tighten the backlash tool to
the clamp on the inner coupling of the tail rotor drive quill. Install the dial indicator support on one of the tail rotor drive
quill studs. Install the dial indicator on the support and position it to contact the dowel pin in the backlash tool, Detail
3. Take the backlash reading at three places approximately 120° apart around the gear and record. Backlash on the
tail rotor drive quill must be within 0.004 to 0.010 inch (0.10 to 0.25 mm).
22.3.
Remove the backlash tools from the tail rotor drive quill, but leave the backlash tool, Detail 2, on the accessory
case input quill.
NOTE
If the backlash tool (212-040-001-3 GIF-1) (Detail 3) is unavailable, the backlash may be determined by
an alternate method. Take backlash readings at three places approximately 120° apart around the gear
and at a distance (radius) of 1.227 inches (31.17 mm) from the gear center. The backlash must be within
the limits noted in Step 22.2..
22.4.
Install the backlash tool (212-040-001-3 GIF-1) (Detail 4) on the pinion shaft of the hydraulic drive quill (46). Install
the dial indicator support on one of the hydraulic pump and tachometer drive quill studs. Install the dial indicator
on the support and position it to contact the dowel pin in the backlash tool Detail 4. Take the backlash reading at
three places approximately 120° apart around the gear and record. The backlash must be within 0.014 to 0.022
inch (0.36 to 0.56 mm).
22.5.
Remove the backlash tools from the hydraulic pump and tachometer drive quill. Remove the backlash tool from
the input quill at the top of the accessory drive sump.
NOTE
If the backlash tool (212-040-001-3 GIF-1) (Detail 4) is unavailable, backlash may be determined by an
alternate method. Take backlash readings at three places approximately 120° apart around the gear and
at a distance (radius) of 1.227 inches (31.17 mm) from the gear center. The backlash must be within the
limits noted in Step 22.4.
412-A-63-10-00-21A-710A-B
Applicable to: ALL
Page 00208-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
23.
Apply sealant to the required areas and paint the sump in accordance with 412-A-63-10-00-06A-257A-B / 00135.
Applicable to: ALL
412-A-63-10-00-21A-710A-B
ECCN EAR99
31 MAY 2023 Page 00208-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00210-A-001-01
Figure 1. Accessory and Tail Rotor Drive Case Assembly (Sheet 1 of 1)
412-A-63-10-00-21A-710A-B
Applicable to: ALL
Page 00208-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00029-A-001-01
Figure 2. Accessory and Tail Rotor Drive and Sump Assembly (Sheet 1 of 4)
Applicable to: ALL
412-A-63-10-00-21A-710A-B
ECCN EAR99
31 MAY 2023 Page 00208-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00030-A-001-01
Figure 2. Accessory and Tail Rotor Drive and Sump Assembly (Sheet 2 of 4)
412-A-63-10-00-21A-710A-B
Applicable to: ALL
Page 00208-8 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00031-A-001-01
Figure 2. Accessory and Tail Rotor Drive and Sump Assembly (Sheet 3 of 4)
Applicable to: ALL
412-A-63-10-00-21A-710A-B
ECCN EAR99
31 MAY 2023 Page 00208-9
BHT-412-CRO
ICN-412-A-631000-B-97499-00032-A-001-01
Figure 2. Accessory and Tail Rotor Drive and Sump Assembly (Sheet 4 of 4)
412-A-63-10-00-21A-710A-B
Applicable to: ALL
Page 00208-10 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Rotary Oil Pump - Disassembly
Procedure
1.
Remove the retaining ring (1, Figure 1).
DO NOT REMOVE ANY PART OF PUMP BY FORCE. LOOSEN PARTS BY TAPPING LIGHTLY WITH
A FIBER MALLET.
2.
Remove the retainer plate (2). Do not remove the bearing (3) from the retainer plate.
3.
Remove the inner gerotor (6), shaft (7) and outer gerotor (5).
4.
Remove the retaining rings (4 and 9).Discard the retaining rings.
5.
Remove the inner gerotor (6) and the key (8) from the shaft (7). Do not remove the bearing (10) or the dowel pin
(11) from the body (12).
Applicable to: ALL
412-A-63-10-00-22A-530A-B
ECCN EAR99
31 MAY 2023 Page 00209-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00215-A-001-01
Figure 1. Rotary Oil Pump (Sheet 1 of 1)
412-A-63-10-00-22A-530A-B
Applicable to: ALL
Page 00209-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Rotary Oil Pump - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Corrosion preventive compound
Drycleaning solvent
Clean cloth
C-105
C-304
C-516
AR
AR
AR
Remarks
Procedure
1.
Remove the sealant with a plastic scraper.
2.
Clean all the rotary oil pump parts with drycleaning solvent (C-304). Use a soft bristle brush to dislodge stubborn
deposits.
3.
Dry the parts with a clean cloth (C-516) or dry filtered compressed air.
DO NOT HANDLE UNOILED BEARINGS WITH BARE HANDS.
NOTE
Parts treated per the following step may be left covered in indoor storage for approximately 150 hours
without being affected by corrosion.
4.
Coat the parts with corrosion preventive compound (C-105) immediately after cleaning (BHT-ALL-SPM, Standard
Practices Manual).
Applicable to: ALL
412-A-63-10-00-22A-258A-B
ECCN EAR99
31 MAY 2023 Page 00210-1
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-22A-258A-B
Applicable to: ALL
Page 00210-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Rotary Oil Pump - Inspection
Procedure
1.
Inspect the bearings (3 and 10, Figure 1), shaft (7), inner and outer gerotors (6 and 5), and body (12) for scoring or
indentations. Visible damage is not permitted.
2.
Inspect the shaft (7) by magnetic particle inspection. Demagnetize the shaft after the magnetic particle inspection
(BHT-ALL-SPM, Standard Practices Manual).
3.
Inspect the external part of the body (12) for mechanical and corrosion damage. Superficial mechanical damage is
permitted without repair. Cracked or distorted parts are not permitted. Superficial corrosion is permitted if polished out
and area treated for corrosion prevention.
4.
Inspect the insert (13) for damaged threads and secure installation in the body. Damaged threads and/ or a loose
insert are not permitted.
NOTE
Wear limits are provided to show the required fit between mating parts. It is not intended that all
dimensions be checked as prescribed overhaul procedure; however, parts that show evidence of wear
or physical damage must be checked dimensionally.
5.
Inspect the following parts dimensionally. Parts that do not fall within the inspection limits are not permitted.
NOMENCLATURE
MINIMUM INCH (MM)
MAXIMUM INCH (MM)
Outer Gerotor Width
0.7080 (17.9832)
0.7085 (17.9959)
Body Chamber Width
0.7100 (18.0340)
0.7105 (18.0467)
Allowable Chamber Face Clearance
0.0015 (0.0381)
0.0027 (0.0686)
Outer Gerotor Outside Diameter
2.1220 (53.8988)
2.1225 (53.9115)
Body Inside Diameter
2.1250 (53.9750)
2.1255 (53.9877)
Allowable Clearance
0.0025 (0.0635)
0.0040 (0.1016)
Driveshaft Outside Diameter
0.4985 (12.6619)
0.4990 (12.6746)
Bearing Inside Diameter
0.5000 (12.7000)
0.5005 (12.7127)
Allowable Clearance
0.0010 (0.0254)
0.0025 (0.0635)
Applicable to: ALL
412-A-63-10-00-22A-280A-B
ECCN EAR99
31 MAY 2023 Page 00211-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00215-A-001-01
Figure 1. Rotary Oil Pump (Sheet 1 of 1)
412-A-63-10-00-22A-280A-B
Applicable to: ALL
Page 00211-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Rotary Oil Pump - Repair
Procedure
1.
Repair is limited to the replacement of non-acceptable parts. Refer to the BHT-ALL-SPM, Standard Practices Manual
for the procedure to replace the insert (13, Figure 1).
Applicable to: ALL
412-A-63-10-00-22A-685A-B
ECCN EAR99
31 MAY 2023 Page 00212-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00215-A-001-01
Figure 1. Rotary Oil Pump (Sheet 1 of 1)
412-A-63-10-00-22A-685A-B
Applicable to: ALL
Page 00212-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Rotary Oil Pump - Assembly
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Drycleaning solvent
C-304
AR
Remarks
Procedure
1.
Clean all the parts with drycleaning solvent (C-304) and drain.
DO NOT HANDLE UNOILED PARTS WITH BARE HANDS.
2.
Coat all the parts with the same oil used in the transmission and drain.
3.
Install a new retaining ring (9, Figure 1) in the inboard groove of the shaft (7).
4.
Insert the key (8) in the shaft (7) and install the inner gerotor (6) so that the keyway engages the key.
5.
Install a new retaining ring (4) on the outboard end of the shaft (7).
6.
Install the shaft (7) in the body (12).
7.
Install the outer gerotor (5) over the inner gerotor (6).
8.
Install the retainer plate (2) on the shaft (7). Make sure that the dowel in the body (12) engages the hole in retainer
plate (2).
9.
Install the retaining ring (1) in the body (12). The retaining ring has a beveled and a flat side. The flat side must
be against the plate. Make sure that the ring is fully seated in the groove.
10.
Rotate the shaft (7) to ensure that the internal parts turn freely.
Applicable to: ALL
412-A-63-10-00-22A-710A-B
ECCN EAR99
31 MAY 2023 Page 00213-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00215-A-001-01
Figure 1. Rotary Oil Pump (Sheet 1 of 1)
412-A-63-10-00-22A-710A-B
Applicable to: ALL
Page 00213-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Oil Filter (Internal) (02W101633) - Disassembly
Procedure
1.
Straighten the tangs on the washer (5, Figure 1).
2.
Remove the nut (4) and the washer (5).
3.
Remove the wafer screens (7), and the spacers (6) from the filter body (8). Inspect the screens for metal particles.
Applicable to: ALL
412-A-63-10-00-23A-530A-B
ECCN EAR99
31 MAY 2023 Page 00214-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00216-A-001-01
Figure 1. Oil Filter (Internal) (Sheet 1 of 1)
412-A-63-10-00-23A-530A-B
Applicable to: ALL
Page 00214-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Oil Filter (Internal) (02W101633) - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Drycleaning solvent
C-304
AR
Remarks
Procedure
1.
Clean the oil filter with drycleaning solvent (C-304) and dry with compressed air.
Applicable to: ALL
412-A-63-10-00-23A-258A-B
ECCN EAR99
31 MAY 2023 Page 00215-1
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-23A-258A-B
Applicable to: ALL
Page 00215-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Oil Filter (Internal) (02W101633) - Inspection
Procedure
1.
Inspect the wafer screens (7, Figure 1) for distortion and tears. Damage that can be visually detected is not permitted.
2.
Inspect the spacers (6) for corrosion and deformation. Damage in excess of superficial is not permitted.
3.
Inspect the screen retention nut (4) for corrosion and thread damage. Damage in excess of superficial is not permitted.
4.
Inspect the filter body (8) for mechanical and corrosion damage. Damage in excess of superficial is not permitted.
Applicable to: ALL
412-A-63-10-00-23A-280A-B
ECCN EAR99
31 MAY 2023 Page 00216-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00216-A-001-01
Figure 1. Oil Filter (Internal) (Sheet 1 of 1)
412-A-63-10-00-23A-280A-B
Applicable to: ALL
Page 00216-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Oil Filter (Internal) (02W101633) - Repair
Procedure
1.
Repair of oil filter (Figure 1) is limited to replacement of defective parts.
Applicable to: ALL
412-A-63-10-00-23A-685A-B
ECCN EAR99
31 MAY 2023 Page 00217-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00216-A-001-01
Figure 1. Oil Filter (Internal) (Sheet 1 of 1)
412-A-63-10-00-23A-685A-B
Applicable to: ALL
Page 00217-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Oil Filter (Internal) (02W101633) - Assembly
Procedure
1.
Put the wafer screens (7, Figure 1), spacers (6), washer (5), and nut (4) on the filter body (8).
2.
Tighten the nut (4) just enough to prevent the wafer screens (7) from turning. Bend the tangs of the washer (5)
against the side of the nut (4).
3.
Put the oil filter (4, Figure 2) in position on the accessory and tail rotor drive case (22) without the packing (5). If the
filter does not seat properly in the case, the filter is not assembled properly. Remove the filter from the case.
Applicable to: ALL
412-A-63-10-00-23A-710A-B
ECCN EAR99
31 MAY 2023 Page 00218-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00216-A-001-01
Figure 1. Oil Filter (Internal) (Sheet 1 of 1)
412-A-63-10-00-23A-710A-B
Applicable to: ALL
Page 00218-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00029-A-001-01
Figure 2. Accessory and Tail Rotor Drive and Sump Assembly (Sheet 1 of 4)
Applicable to: ALL
412-A-63-10-00-23A-710A-B
ECCN EAR99
31 MAY 2023 Page 00218-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00030-A-001-01
Figure 2. Accessory and Tail Rotor Drive and Sump Assembly (Sheet 2 of 4)
412-A-63-10-00-23A-710A-B
Applicable to: ALL
Page 00218-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00031-A-001-01
Figure 2. Accessory and Tail Rotor Drive and Sump Assembly (Sheet 3 of 4)
Applicable to: ALL
412-A-63-10-00-23A-710A-B
ECCN EAR99
31 MAY 2023 Page 00218-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00032-A-001-01
Figure 2. Accessory and Tail Rotor Drive and Sump Assembly (Sheet 4 of 4)
412-A-63-10-00-23A-710A-B
Applicable to: ALL
Page 00218-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Full Flow Debris Monitor (212-040-122-101 and -103) - Disassembly
Procedure
1.
Remove the scupper (1, Figure 1), debris scavenge cup/screen tube assembly (2) with filter element (3), and packing
(4). Discard the packing (4).
Applicable to: ALL
412-A-63-10-00-24A-530A-B
ECCN EAR99
28 OCT 2024 Page 00219-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00217-A-001-01
Figure 1. Full Flow Debris Monitor (Sheet 1 of 1)
412-A-63-10-00-24A-530A-B
Applicable to: ALL
Page 00219-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Full Flow Debris Monitor (212-040-122-101 and -103) - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Drycleaning solvent
Clean cloth
C-304
C-516
AR
AR
Remarks
Procedure
1.
Clean the debris scavenge cup/screen tube assembly (2, Figure 1), filter element (3), and scupper (1) with drycleaning
solvent (C-304). Clean the outer surface of the magnetics with a clean cloth (C-516). Dry with filtered compressed air.
Applicable to: ALL
412-A-63-10-00-24A-258A-B
ECCN EAR99
14 NOV 2023 Page 00220-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00217-A-001-01
Figure 1. Full Flow Debris Monitor (Sheet 1 of 1)
412-A-63-10-00-24A-258A-B
Applicable to: ALL
Page 00220-2 14 NOV 2023
ECCN EAR99
BHT-412-CRO
Full Flow Debris Monitor (212-040-122-101 and -103) - Inspection
Procedure
1.
Examine the filter element (3, Figure 1) for distortion and tears. Damage that can be visually sense is not permitted.
2.
Examine the scupper (1) and the debris scavenge cup/screen tube assembly (2) for thread damage, physical
damage, and corrosion.
3.
Examine the full flow debris monitor (6) and electrical receptacle (5) for physical damage, mechanical damage
and corrosion.
Applicable to: ALL
412-A-63-10-00-24A-280A-B
ECCN EAR99
14 NOV 2023 Page 00221-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00217-A-001-01
Figure 1. Full Flow Debris Monitor (Sheet 1 of 1)
412-A-63-10-00-24A-280A-B
Applicable to: ALL
Page 00221-2 14 NOV 2023
ECCN EAR99
BHT-412-CRO
Full Flow Debris Monitor (212-040-122-101 and -103) - Repair
Procedure
1.
Repair of the full flow debris monitor (6, Figure 1) is limited to the replacement of defective parts.
Applicable to: ALL
412-A-63-10-00-24A-685A-B
ECCN EAR99
14 NOV 2023 Page 00222-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00217-A-001-01
Figure 1. Full Flow Debris Monitor (Sheet 1 of 1)
412-A-63-10-00-24A-685A-B
Applicable to: ALL
Page 00222-2 14 NOV 2023
ECCN EAR99
BHT-412-CRO
Full Flow Debris Monitor (212-040-122-101 and -103) - Assembly
Procedure
1.
Lubricate the new packing (4, Figure 1) with the same oil used in the transmission and install the packing on the
filter element (3).
2.
DELETED
3.
DELETED
4.
Install the debris scavenge cup/screen tube assembly (2) with filter element (3) and the scupper (1) onto the full flow
debris monitor (6). Torque the debris scavenge cup/screen tube assembly (2) 22 to 30 inch-pounds (2.48 to 3.39 Nm).
Applicable to: ALL
412-A-63-10-00-24A-710A-B
ECCN EAR99
28 OCT 2024 Page 00223-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00217-A-001-01
Figure 1. Full Flow Debris Monitor (Sheet 1 of 1)
412-A-63-10-00-24A-710A-B
Applicable to: ALL
Page 00223-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Accessory and Tail Rotor Drive Quill (212-040-365-023 and -115) - Disassembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Wrench Assembly
Wrench
Plate Assembly
Bearing Removal Bar
Bearing Removal Bar
Wrench Assembly
T101305
T101449
T101455
T101566
T101567
T101568
1
1
1
1
1
1
Remarks
Procedure
1.
Remove the clip (2, Figure 1).
2.
If not previously accomplished, remove the oil pump shaft retaining ring in the base of the pinion (11). Hold the
pinion with the wrench assembly (T101568) and remove the nut (3) with the wrench assembly (T101305). Remove
the tab washer (4).
3.
Press the pinion (11) out of the duplex bearing (5).
4.
Hold the tail rotor drive spiral bevel gear sleeve (6) with the plate assembly (T101455) and remove the bearing
retaining nut (1) with the wrench (T101449).
IN Step 5. AND Step 6., EXERCISE CARE TO PROPERLY POSITION BEARING REMOVAL BAR ON
BEARINGS TO AVOID DAMAGING BEARING OR SLEEVE.
RETAIN BEARINGS AS A MATCHED SET.
5.
Insert the bearing removal bar (T101566) through the slot in the side of the tail rotor drive spiral bevel gear sleeve (6)
and press the duplex bearing (5) out of the sleeve. Keep the bearings together as a matched set.
6.
Remove the retaining ring (10).
7.
Insert the bearing removal bar (T101567) through the slot in the side of the tail rotor drive spiral bevel gear sleeve
(6) and press the roller bearing (9) out of the sleeve.
8.
Remove the three screws (8) and the shim plate (7). Mark the shim plate for installation on the same sleeve.
Applicable to: ALL
412-A-63-10-00-25A-530A-B
ECCN EAR99
31 MAY 2023 Page 00224-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00028-A-001-01
Figure 1. Accessory and Tail Rotor Drive Quill Assembly (Sheet 1 of 1)
412-A-63-10-00-25A-530A-B
Applicable to: ALL
Page 00224-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Accessory and Tail Rotor Drive Quill (212-040-365-023 and -115) - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Corrosion preventive compound
Drycleaning solvent
Solvent
Clean cloth
C-105
C-304
C-334
C-516
AR
AR
AR
AR
Remarks
Procedure
1.
Clean all the quill parts with drycleaning solvent (C-304). Use a soft bristle brush to dislodge stubborn deposits. All
parts except the bearings may be cleaned by vapor degreasing method (BHT-ALL-SPM, Chapter 5, Standard
Practices Manual).
DO NOT ALLOW BEARINGS TO SPIN WHILE DRYING.
2.
Dry the parts with a clean cloth (C-516) or dry filtered compressed air.
DO NOT HANDLE UNOILED BEARINGS WITH BARE HANDS.
NOTE
Parts treated per the following step may be left covered in indoor storage for approximately 150 hours
without being affected by corrosion.
3.
Coat the bearings with corrosion preventive compound (C-105) immediately after cleaning (BHT-ALL-SPM, Standard
Practices Manual).
Applicable to: ALL
412-A-63-10-00-25A-258A-B
ECCN EAR99
31 MAY 2023 Page 00225-1
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-25A-258A-B
Applicable to: ALL
Page 00225-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Accessory and Tail Rotor Drive Quill (212-040-365-023 and -115) - Inspection
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
India stone
C-464
AR
Remarks
Procedure
NOTE
Quill Wear/Damage Limits: The quill wear limits are provided to show the required fit between parts. It is
not intended that wear be measured as a required overhaul procedure.
1.
Inspect the quill parts for wear and damage. If there is evidence of wear, measure the parts, as shown in Figure 1.
Wear in excess of the limits shown is not permitted.
2.
Inspect the following parts by magnetic particle inspection (Code M) or fluorescent penetrant inspection (Code
F), as applicable. Demagnetize the parts after the magnetic particle inspection. Refer to Table 2 and the
BHT-ALL-SPM, Standard Practices Manual for the procedure.
Figure 2INDEX NO.
NOMENCLATURE
CODE
1
Bearing Retaining Nut
F
3
Nut
M
6
Tail Rotor Drive Spiral Bevel Gear
Sleeve
F
11
Pinion
M
Table 2. Magnetic Particle Inspection
PART NUMBER
NOMENCLATURE
ITEM AND FIGURE
SET UP AND MAGNETIZATION CURRENT REQUIREMENTS
ACCESSORY AND TAIL ROTOR DRIVE QUILL (212-040-365-023 AND -115)
DELETED
204-040-230-001
Nut
3, Figure 2
SET UP:
Place part over a 1.0-inch (25-mm) diameter central conductor.
Current for primary diameters, magnetize at 1120 amps.
Omit coil shot.
212-040-150-005
Pinion
11, Figure 2
SET UP:
Place part over a 0.7-inch (18-mm) diameter central conductor.
Current for primary diameters, magnetize at 2550 amps.
Optional current for secondary diameters, magnetize at 1180 amps.
Omit coil shot.
NOTES:
1. Magnetization currents provided are applicable to magnetic particle inspection apparatus using Direct Current (DC) . If an
Alternating Current (AC) apparatus is used, adjust the current as follows: AC= 0.667 x DC.
Applicable to: ALL
412-A-63-10-00-25A-280A-B
ECCN EAR99
28 OCT 2024 Page 00226-1
BHT-412-CRO
Table 2. Magnetic Particle Inspection (continued)
2. Ferrous parts requiring magnetic particle inspection that are not addressed in the attached material, are to be inspected in
accordance with the general procedures outlined in ASTM E1444 standard practices (BHT-ALL-SPM, Chapter 6, Standard
Practices Manual).
3. Part numbers listed apply to all successive dash numbers for that component unless otherwise specified.
3.
Inspect the nuts (1 and 3) for damaged threads. Damage that can be detected visually is not permitted.
4.
Inspect the duplex bearings (5) for spalling, scoring, pitting, brinelling, corrosion damage, cracked or broken retainers,
and for roughness when rotated. Damage that can be detected visually or by feel is not permitted.
5.
Inspect the tail rotor drive spiral bevel gear sleeve (6) for corrosion damage, loose or damaged bearing liner, and
damaged threads. Dents and nicks on the top surface of the flange up to 0.030 inch (0.76 mm) in depth are permitted
if polished out and blended into the flat surface with a minimum radius of 0.12 inch (3.0 mm) and surface finish of 63
RHR or better. Damaged bearing liner and/or damaged threads are not permitted.
6.
Inspect the roller bearing (9) for spalling, scoring, pitting, brinelling, corrosion damage, and cracked or broken roller
retainers. Any damage that can be felt with a 0.020-inch (0.51-mm) spherical radius probe is cause for rejection.
7.
Inspect the pinion (11) for spalled, scuffed, pitted, chipped, or dented teeth. Inspect the roller bearing surface for
spalling, scoring, pitting, brinelling, and corrosion damage. Inspect the splines for chipped, pitted, or excessively
worn teeth. Inspect the threads for damage. Very small dents and nicks on the pinion teeth that can be polished
out with a fine india stone (C-464) are permitted if polished out, providing the dents and nicks do not extend into
the face of the gear teeth.
412-A-63-10-00-25A-280A-B
Applicable to: ALL
Page 00226-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00213-A-001-01
Figure 1. Accessory and Tail Rotor Drive and Sump Assembly - Damage Limits (Sheet 1 of 3)
Applicable to: ALL
412-A-63-10-00-25A-280A-B
ECCN EAR99
28 OCT 2024 Page 00226-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00214-A-001-01
Figure 1. Accessory and Tail Rotor Drive and Sump Assembly - Damage Limits (Sheet 2 of 3)
412-A-63-10-00-25A-280A-B
Applicable to: ALL
Page 00226-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-01212-A-001-01
Figure 1. Accessory and Tail Rotor Drive and Sump Assembly - Damage Limits (Sheet 3 of 3)
Applicable to: ALL
412-A-63-10-00-25A-280A-B
ECCN EAR99
28 OCT 2024 Page 00226-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00028-A-001-01
Figure 2. Accessory and Tail Rotor Drive Quill Assembly (Sheet 1 of 1)
412-A-63-10-00-25A-280A-B
Applicable to: ALL
Page 00226-6 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Accessory and Tail Rotor Drive Quill (212-040-365-023 and -115) - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Chemical film material
Abrasive cloth or paper
India stone
C-100
C-406
C-464
AR
AR
AR
Remarks
Procedure
1.
Polish out nicks and dents on the tail rotor drive spiral bevel gear sleeve (6, Figure 1) that are within the limits noted in
412-A-63-10-00-25A-280A-B / 00226. Use abrasive cloth or paper (C-406) to polish out damage. Comply with the
radius and surface finish limits noted in 412-A-63-10-00-25A-280A-B / 00226.
2.
Polish out very small nicks and dents on the pinion (11) teeth provided the dents and nicks do not extend into
the face of the gear teeth.
3.
Touch up the areas on the tail rotor drive spiral bevel sleeve (6) where chemical film was removed. Use chemical film
material (C-100) for aluminum (BHT-ALL-SPM, Standard Practices Manual).
4.
Polish out minor dents and nicks on the spline teeth of the tail rotor quill adapter for the accessory and tail rotor drive
quill (10, Figure 2) with a fine india stone (C-464). Do not exceed the limits defined in Figure 3.
Applicable to: ALL
412-A-63-10-00-25A-685A-B
ECCN EAR99
31 MAY 2023 Page 00227-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00028-A-001-01
Figure 1. Accessory and Tail Rotor Drive Quill Assembly (Sheet 1 of 1)
412-A-63-10-00-25A-685A-B
Applicable to: ALL
Page 00227-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00029-A-001-01
Figure 2. Accessory and Tail Rotor Drive and Sump Assembly (Sheet 1 of 4)
Applicable to: ALL
412-A-63-10-00-25A-685A-B
ECCN EAR99
31 MAY 2023 Page 00227-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00030-A-001-01
Figure 2. Accessory and Tail Rotor Drive and Sump Assembly (Sheet 2 of 4)
412-A-63-10-00-25A-685A-B
Applicable to: ALL
Page 00227-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00031-A-001-01
Figure 2. Accessory and Tail Rotor Drive and Sump Assembly (Sheet 3 of 4)
Applicable to: ALL
412-A-63-10-00-25A-685A-B
ECCN EAR99
31 MAY 2023 Page 00227-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00032-A-001-01
Figure 2. Accessory and Tail Rotor Drive and Sump Assembly (Sheet 4 of 4)
412-A-63-10-00-25A-685A-B
Applicable to: ALL
Page 00227-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00213-A-001-01
Figure 3. Accessory and Tail Rotor Drive and Sump Assembly - Damage Limits (Sheet 1 of 3)
Applicable to: ALL
412-A-63-10-00-25A-685A-B
ECCN EAR99
31 MAY 2023 Page 00227-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00214-A-001-01
Figure 3. Accessory and Tail Rotor Drive and Sump Assembly - Damage Limits (Sheet 2 of 3)
412-A-63-10-00-25A-685A-B
Applicable to: ALL
Page 00227-8 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-01212-A-001-01
Figure 3. Accessory and Tail Rotor Drive and Sump Assembly - Damage Limits (Sheet 3 of 3)
Applicable to: ALL
412-A-63-10-00-25A-685A-B
ECCN EAR99
31 MAY 2023 Page 00227-9
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-25A-685A-B
Applicable to: ALL
Page 00227-10 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Accessory and Tail Rotor Drive Quill (212-040-365-023 and -115) - Assembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Wrench Assembly
Holding Plate Assembly
Wrench
Wrench Assembly
T101305
T101455
T101449
T101568
1
1
1
1
Remarks
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Drycleaning solvent
Lockwire
C-304
C-405
AR
AR
Remarks
Procedure
1.
Clean all the parts with drycleaning solvent (C-304) and drain.
DO NOT HANDLE UNOILED PARTS WITH BARE HANDS.
2.
Coat all the parts with the same oil used in the transmission and drain.
3.
Install the shim plate (7, Figure 1) as follows:
SHIM PLATE (7) MUST BE INSTALLED ON SAME TAIL ROTOR DRIVE SPIRAL BEVEL GEAR SLEEVE
(6) FROM WHICH REMOVED OR GEAR BACKLASH WILL PROBABLY BE INCORRECT.
3.1.
Inspect the shim plate (7) and the tail rotor drive spiral bevel gear sleeve (6) for a serial number. If same serial
number is legible on both parts, or if the shim plate was indexed at the time of removal, install the shim plate as
outlined in Step 3.2.. If the shim plate cannot be positively identified, determine the required shim thickness
as outlined in Step 3.3..
3.2.
Put a shim plate (7) of the correct thickness on the tail rotor drive spiral bevel gear sleeve (6). Countersink the shim
plate in three places for the screws (8). Install the three screws.
3.3.
Determine the required thickness for the shim plate (7) for the tail rotor drive spiral bevel gear sleeve (6) as follows:
3.3.1.
Inspect the tail rotor drive spiral bevel gear sleeve (6) for the reference dimension, which should be metal stamped
or vibro-etched on the sleeve adjacent to the mounting surface for the shim plate (7). Record this dimension and
location on the sleeve.
3.3.2.
Measure the thickness of the shim plate (7) and record.
3.3.3.
Subtract the shim plate thickness from the reference dimension noted in Step 3.3.1.. The resulting value must fall
within the minimum/maximum dimensions listed as follows. This is the required value for a plated shim plate.
3.4.
SHIM
MINIMUM INCH (MM)
MAXIMUM INCH (MM)
Shim Plate (7), Tail Rotor Drive Quill
0.9895 (25.133)
0.9905 (25.158)
Procure a shim plate (7) the dimension determined in Step 3.3. as described in Step 3.2..
Applicable to: ALL
412-A-63-10-00-25A-710A-B
ECCN EAR99
31 MAY 2023 Page 00228-1
BHT-412-CRO
DUPLEX BEARING MUST BE A MATCHED SET WITH SAME SERIAL NUMBER ON BOTH
BEARINGS.
4.
Press the duplex bearing (5) into the tail rotor drive spiral bevel gear sleeve (6), face-to-face, by pressing on the
outer race with a suitable sleeve.
5.
Press the roller bearing (9) into the tail rotor drive spiral bevel gear sleeve (6) with a suitable sleeve and install the
retaining ring (10).
6.
Support the duplex bearings (5) on the inner race and press the pinion (11) into the bearings.
7.
Put the wrench assembly (T101568) in a vise with the splined end up.
8.
Put the quill on the wrench assembly (T101568) with the pinion teeth down.
9.
Install the tab washer (4) and nut (3). Torque the nut 180 to 200 foot-pounds (244.05 to 271.16 Nm) with the wrench
assembly (T101305).
10.
Install the nut locking clip (2) and remove the quill from the wrench assembly (T101568).
11.
Hold the tail rotor drive spiral bevel gear sleeve (6) with the holding plate assembly (T101455) and install the bearing
retaining nut (1). With the wrench (T101449), torque the nut 100 to 150 foot-pounds (135.58 to 203.37 Nm).
12.
Secure the bearing retaining nut (1) with lockwire (C-405).
13.
Check the pinion (11) for free rotation.
412-A-63-10-00-25A-710A-B
Applicable to: ALL
Page 00228-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00028-A-001-01
Figure 1. Accessory and Tail Rotor Drive Quill Assembly (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-25A-710A-B
ECCN EAR99
31 MAY 2023 Page 00228-3
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-25A-710A-B
Applicable to: ALL
Page 00228-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Tail Rotor Drive Quill (212-040-365-025) - Disassembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Wrench Assembly
Removal Bar
Bar
Holding Plate Assembly
Wrench
T101307
T101333
T101334
T101455
T101600
1
1
1
1
1
Remarks
Procedure
BLOCK THE OUTER COUPLING SO THAT IT WILL REMAIN IN THE OUTBOARD (EXTENDED)
POSITION. THIS WILL STABILIZE THE OUTER COUPLING DURING DISASSEMBLY AND
ASSEMBLY OR DAMAGE TO THE COUPLING MAY OCCUR.
NOTE
SN: 36020-36999 or 37002-37999 or SN: 38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed:
Refer to 412-A-63-10-00-27A-530A-B / 00234.
1.
Push the plate assembly (26, Figure 1) against the centering spring (25) and remove the retaining ring (27).
2.
Remove the plate assembly (26) and the centering spring (25).
3.
Remove the lock spring (24).
4.
Install a 1/4-20 UNC threaded bolt into the spring retainer (23) and pull on the bolt to withdraw the retainer from
the inner coupling (19).
5.
Remove the packing (22) from the spring retainer (23). Discard the packing.
6.
Hold the outer coupling (18) with the wrench assembly (T101307) or hold the gear (4) with the holding plate assembly
(T101455), position the square adapter through the wrench, and remove the coupling retaining bolt (21) and the
special washer (20).
7.
Remove the couplings (18 and 19) from the gear (4).
8.
Separate the couplings (18 and 19) and remove the seal (17) from the outer coupling (18). Discard the seal.
9.
Put the quill sleeve (10) in the holding plate assembly (T101455). Remove the bearing retaining nut (13) with the
wrench (T101600). Remove the seal (14) and the packing (12) from the nut. Discard the seal and the packing.
10.
Remove the spacer (16) and the packing (15). Discard the packing.
11.
Press the gear (4) out of the sleeve (10).
12.
Remove the retaining ring (1), funnel (2), and packing (3). Discard the packing.
13.
Remove the cork (5) from the gear (4). Discard the cork.
IN Step 14. AND Step 16., EXERCISE CARE TO PROPERLY POSITION BEARING REMOVAL BAR
ON BEARINGS TO AVOID DAMAGING BEARING OR SLEEVE (10).
14.
Remove the retaining ring (6).
15.
Press the roller bearing (7) out of the sleeve (10) with the removal bar (T101333).
Applicable to: ALL
412-A-63-10-00-26A-530A-B
ECCN EAR99
28 OCT 2024 Page 00229-1
BHT-412-CRO
16.
Press the duplex bearings (11) out of the sleeve (10) with the bar (T101334).
17.
Remove the three screws (9) and the shim plate (8). Mark the shim plate with the sleeve serial number for installation
on the same sleeve.
412-A-63-10-00-26A-530A-B
Applicable to: ALL
Page 00229-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00045-A-001-01
Figure 1. Tail Rotor Drive Quill Assembly (Sheet 1 of 2)
Applicable to: ALL
412-A-63-10-00-26A-530A-B
ECCN EAR99
28 OCT 2024 Page 00229-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00046-A-001-01
Figure 1. Tail Rotor Drive Quill Assembly (Sheet 2 of 2)
412-A-63-10-00-26A-530A-B
Applicable to: ALL
Page 00229-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Tail Rotor Drive Quill (212-040-365-025) - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Corrosion preventive compound
Drycleaning solvent
MEK
Solvent
Clean cloth
C-105
C-304
C-309
C-334
C-516
AR
AR
AR
AR
AR
Remarks
Procedure
NOTE
SN: 36020-36999 or 37002-37999 or SN: 38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed:
Refer to 412-A-63-10-00-27A-258A-B / 00235.
1.
Remove the sealant with a plastic scraper and a clean cloth (C-516) moistened with MEK (C-309).
2.
Clean all the quill parts with drycleaning solvent (C-304). Use a soft bristle brush to dislodge stubborn deposits. All
the parts except the bearings may be cleaned with solvent (C-334) by vapor degreasing method.
DO NOT ALLOW BEARINGS TO SPIN WHILE DRYING.
3.
Dry the parts with a clean cloth (C-516) or dry filtered compressed air.
DO NOT HANDLE UNOILED BEARINGS WITH BARE HANDS.
NOTE
Parts treated per the following step may be left covered in indoor storage for approximately 150 hours
without being affected by corrosion.
4.
Coat the bearings with corrosion preventive compound (C-105) immediately after cleaning (BHT-ALL-SPM, Standard
Practices Manual).
Applicable to: ALL
412-A-63-10-00-26A-258A-B
ECCN EAR99
28 OCT 2024 Page 00230-1
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-26A-258A-B
Applicable to: ALL
Page 00230-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Tail Rotor Drive Quill (212-040-365-025) - Inspection
Procedure
NOTE
SN: 36020-36999 or 37002-37999 or SN: 38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed:
Refer to 412-A-63-10-00-27A-280A-B / 00236.
NOTE
Quill Wear/Damage Limits: The quill wear damage limits are provided to show the required fit between
parts. It is not intended that wear be measured as a required overhaul procedure.
1.
Inspect the quill parts for wear and damage. If there is evidence of wear, measure the parts, as shown in Figure 1.
Wear in excess of the limits shown is not permitted.
2.
Inspect the following parts by magnetic particle inspection (Code M) or fluorescent penetrant inspection (Code
F), as applicable. Demagnetize the parts after the magnetic particle inspection. Refer to Table 2 and the
BHT-ALL-SPM, Standard Practices Manual for the procedure.
Figure 2INDEX NO.
NOMENCLATURE
CODE
4
Gear
M
10
Sleeve
F
18
Coupling, Outer
M
19
Coupling, Inner
M
Table 2. Magnetic Particle Inspection
PART NUMBER
NOMENCLATURE
ITEM AND FIGURE
SET UP AND MAGNETIZATION CURRENT REQUIREMENTS
TAIL ROTOR DRIVE QUILL ASSEMBLY (212-040-365-025)
204-040-603-009
Inner Coupling
19, Figure 2
SET UP:
Place part over a 1.0-inch (25-mm) diameter central conductor.
Current for primary diameters, magnetize at 1180 amps.
Omit coil shot.
204-040-604-005
Outer Coupling
18, Figure 2
SET UP:
Place part over a 2-inch (51-mm) diameter central conductor.
Current for primary diameters, magnetize at 3030 amps.
Optional current for secondary diameters, magnetize at 1700 amps.
Omit coil shot.
212-040-151-009
Gear
4, Figure 2
Refer to 412 HP/EP magnetic particle.
NOTES:
1. Magnetization currents provided are applicable to magnetic particle inspection apparatus using Direct Current (DC) . If an
Alternating Current (AC) apparatus is used, adjust the current as follows: AC= 0.667 x DC.
Applicable to: ALL
412-A-63-10-00-26A-280A-B
ECCN EAR99
28 OCT 2024 Page 00231-1
BHT-412-CRO
Table 2. Magnetic Particle Inspection (continued)
2. Ferrous parts requiring magnetic particle inspection that are not addressed in the attached material, are to be inspected in
accordance with the general procedures outlined in ASTM E1444 standard practices (BHT-ALL-SPM, Chapter 6, Standard
Practices Manual).
3. Part numbers listed apply to all successive dash numbers for that component unless otherwise specified.
3.
Inspect the gear (4, Figure 2) for spalled, scuffed, pitted, chipped, or dented teeth and abnormal wear patterns.
4.
Inspect the roller bearing (7) surface for spalling, scoring, pitting, brinelling, and corrosion damage. Any damage that
can be felt with a 0.020-inch (0.51-mm) spherical radius probe is cause for rejection.
5.
Inspect the splines of the gear (4) for pitted, chipped, or excessively worn teeth in accordance with Figure 1.
6.
Inspect the threads on the gear (4, Figure 2) for damage. Any visual damage is not permitted.
7.
Inspect the sleeve (10) in accordance with Figure 3.
8.
Inspect the outer coupling (18, Figure 2) visual over temperature indicator (TEMP-PLATES) for discoloration and
overheat condition. Refer to the BHT-412-MM, Chapter 65, Table 1 for condition and corrective action of the over
temperature indicators. Scrap the outer and inner couplings (18 and 19) if any of the following conditions exist:
- The cadmium plating on the outer coupling (18) is discolored (circumferential tan or light brown band) or blistered
- The gear teeth of either coupling are discolored (brown or blue) in the normally bright contact patterns
- Under a 10X magnifying glass, the surface of the gear teeth of either inner or outer coupling exhibits signs
of metal smearing or tearing in the contact patterns
- The grease is very viscous (thick) and has a strong pungent odor
If none of the above conditions exist, the coupling may be returned to service after replacement of the TEMP-PLATES.
NOTE
To ease the inspection of the outer coupling (18) and the inner coupling (19), use a clean piece of white
paper between the teeth of the couplings.
9.
Inspect the outer coupling (18) for chipped, cracked, broken, pitted, or excessively worn spline teeth.
10.
Inspect the inner coupling (19) for chipped, cracked, broken, pitted, or excessively worn spline teeth. Refer to
Figure 4, for acceptable wear patterns.
11.
Inspect the teeth of the inner coupling (19, Figure 2) for non-corrosion pits, indentations, or scratches. Make sure
the pits and the indentations are not larger than 0.030 inch (0.76 mm) across the largest dimension. Make sure the
scratches are not wider than 0.015 inch (0.38 mm). Only one damage is permitted per tooth.
12.
Inspect the duplex bearings (11) for spalling, scoring, pitting, brinelling, and corrosion damage. Inspect the bearings
for cracked or broken retainers and for roughness when rotated. Any damage to the bearings that can be detected
visually or by feel is not permitted.
13.
Inspect the spacer (16) in the seal contact area for roughness and wear. Damage that could result in oil leakage is
not permitted. Inspect the splines for chipped, broken, and worn teeth. Damage that can be detected visually is
not permitted.
14.
Inspect the bearing retaining nut (13) for damaged threads and broken or rounded corners on the tangs. If damage
exist, replace the nut.
15.
Inspect the coupling retaining bolt (21) for damaged threads.
412-A-63-10-00-26A-280A-B
Applicable to: ALL
Page 00231-2 28 OCT 2024
ECCN EAR99
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ICN-412-A-631000-B-97499-00213-A-001-01
Figure 1. Accessory and Tail Rotor Drive and Sump Assembly - Damage Limits (Sheet 1 of 3)
Applicable to: ALL
412-A-63-10-00-26A-280A-B
ECCN EAR99
28 OCT 2024 Page 00231-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00214-A-001-01
Figure 1. Accessory and Tail Rotor Drive and Sump Assembly - Damage Limits (Sheet 2 of 3)
412-A-63-10-00-26A-280A-B
Applicable to: ALL
Page 00231-4 28 OCT 2024
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BHT-412-CRO
ICN-412-A-631000-B-97499-01212-A-001-01
Figure 1. Accessory and Tail Rotor Drive and Sump Assembly - Damage Limits (Sheet 3 of 3)
Applicable to: ALL
412-A-63-10-00-26A-280A-B
ECCN EAR99
28 OCT 2024 Page 00231-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00045-A-001-01
Figure 2. Tail Rotor Drive Quill Assembly (Sheet 1 of 2)
412-A-63-10-00-26A-280A-B
Applicable to: ALL
Page 00231-6 28 OCT 2024
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BHT-412-CRO
ICN-412-A-631000-B-97499-00046-A-001-01
Figure 2. Tail Rotor Drive Quill Assembly (Sheet 2 of 2)
Applicable to: ALL
412-A-63-10-00-26A-280A-B
ECCN EAR99
28 OCT 2024 Page 00231-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00218-A-001-01
Figure 3. Tail Rotor Drive Quill Sleeve - Damage and Wear Limits (Sheet 1 of 4)
412-A-63-10-00-26A-280A-B
Applicable to: ALL
Page 00231-8 28 OCT 2024
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BHT-412-CRO
ICN-412-A-631000-B-97499-00219-A-001-01
Figure 3. Tail Rotor Drive Quill Sleeve - Damage and Wear Limits (Sheet 2 of 4)
Applicable to: ALL
412-A-63-10-00-26A-280A-B
ECCN EAR99
28 OCT 2024 Page 00231-9
BHT-412-CRO
ICN-412-A-631000-B-97499-00220-A-001-01
Figure 3. Tail Rotor Drive Quill Sleeve - Damage and Wear Limits (Sheet 3 of 4)
412-A-63-10-00-26A-280A-B
Applicable to: ALL
Page 00231-10 28 OCT 2024
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BHT-412-CRO
ICN-412-A-631000-B-97499-00221-A-001-01
Figure 3. Tail Rotor Drive Quill Sleeve - Damage and Wear Limits (Sheet 4 of 4)
Applicable to: ALL
412-A-63-10-00-26A-280A-B
ECCN EAR99
28 OCT 2024 Page 00231-11
BHT-412-CRO
ICN-412-A-631000-B-97499-00222-A-001-01
Figure 4. Tail Rotor Drive Coupling - Damage Limits (Sheet 1 of 1)
412-A-63-10-00-26A-280A-B
Applicable to: ALL
Page 00231-12 28 OCT 2024
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BHT-412-CRO
Tail Rotor Drive Quill (212-040-365-025) - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Chemical film material
Cadmium plating solution
Shellac varnish
Epoxy adhesive
MEK
Cleaning compound
Clean cloth
C-100
C-108
C-211
C-298
C-309
C-318
C-516
AR
AR
AR
AR
AR
AR
AR
Remarks
Procedure
NOTE
SN: 36020-36999 or 37002-37999 or SN: 38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed:
Refer to 412-A-63-10-00-27A-685A-B / 00237.
1.
Replace all unserviceable parts.
MAKE SURE THAT THE OIL HOLE IN THE GEAR IS NOT OBSTRUCTED OR DAMAGE TO THE
GEAR WILL OCCUR.
2.
Replace the cork (5, Figure 1) in the gear (4) as follows:
2.1.
Use a new No. 9 short cork and install the cork with shellac varnish (C-211) from 1.030 to 1.150 inches (26.16 to
29.21 mm) to the splined end of the gear, as shown in Figure 1,Section C-C.
2.2.
Make sure that the 0.050 to 0.064 inch (1.27 to 1.62 mm) diameter oil hole is not obstructed.
3.
Refinish the parts, after repair in accordance with the BHT-ALL-SPM, Standard Practices Manual, as follows:
3.1.
Aluminum parts: touch up with chemical film material (C-100).
3.2.
Cadmium plated steel parts: treat reworked areas with cadmium plating solution (C-108) (BHT-ALL-SPM, Standard
Practices Manual).
4.
Replace the visual over-temperature indicator (TEMP-PLATES) on the outer coupling (18) if mutilated or discolored,
as follows:
4.1.
Remove the damaged TEMP-PLATES with a plastic scraper, MEK (C-309), and a clean cloth (C-516). Wipe dry with
a clean cloth (C-516) before MEK evaporates.
BONDING SURFACE AND TEMP-PLATES MUST BE FREE OF ALL CONTAMINATION. ANY
CONTAMINATION COULD ALLOW THE TEMP-PLATES TO COME OFF OR INDICATE FALSE
TEMPERATURE.
4.2.
Prepare the outer coupling (18) surface for bonding by scrubbing the area with a clean cloth (C-516) made moist
with MEK (C-309). Dry with a clean cloth (C-516) before MEK evaporates. The surface must be minimum of 0.0500
inches (1.27 mm) larger than the TEMP-PLATE.
4.3.
Accomplish a water break free test on the prepared bonding surface by applying distilled or demineralized water from
a suitable dispenser (squeeze bottle). The water must flow into a continuous film without gathering into distinct water
droplets within 25 seconds after application. Wipe dry with a clean cloth (C-516). If the coupling bonding surface
Applicable to: ALL
412-A-63-10-00-26A-685A-B
ECCN EAR99
28 OCT 2024 Page 00232-1
BHT-412-CRO
does not meet the water break free test and you have ensured the cleaning materials are not contaminated, clean
the coupling bonding surfaces as follows:
NOTE
Follow the manufactures recommendations for proper water mixtures.
4.3.1.
Scrub the coupling bonding surface with a clean cloth (C-516) and cleaning compound (C-318). Follow the cleaning
with a thorough water rinse.
4.3.2.
Thoroughly dry the coupling surface and repeat the water break test as stated in Step 4.3..
5.
Install the TEMP-PLATES on outer coupling (18) as follows:
IN ORDER TO PREVENT CONTAMINATION OF TEMP-PLATES ADHESIVE BACK, MAKE SURE
THAT WORK AREA AND HANDS ARE THOROUGHLY CLEANED BEFORE WORKING WITH
TEMP-PLATES.
DO NOT PRESS OR RUB THE TEMP-PLATE WITH BARE FINGERS DURING INSTALLATION ON
COUPLING AS THIS WILL CONTAMINATE SURFACE.
5.1.
Remove the protective backing from the TEMP-PLATE and carefully position onto the prepared surface.
5.2.
With a clean cloth (C-516), work the TEMP-PLATE into the contour of the coupling. Make sure the TEMP-PLATE
is in full contact with the coupling surface.
NOTE
Apply epoxy coating to the TEMP-PLATE immediately following installation on the coupling.
6.
Install the epoxy coating over the TEMP-PLATE as follows:
THE USE OF ANY EPOXY ADHESIVE OTHER THAN SPECIFIED IS NOT AUTHORIZED.
6.1.
Mix epoxy adhesive (C-298) per manufacturer recommendations.
6.2.
With a soft bristled brush (artist brush), vigorously mix the epoxy. A few drops of recommended thinner may be added
during mixing to reduce the viscosity to a level that permits uniform brush application of the mixture and will not run
when applied to a vertical surface. The final viscosity of the mixture should be similar to a heavy bodied paint.
TOO THIN OF AN EPOXY COATING MAY SEEP INTO TEMP-PLATE CAUSING INDICATOR DOTS TO
TURN BLACK, IN WHICH EVENT, TEMP-PLATE MUST BE REPLACED.
6.3.
Uniformly apply epoxy coating over the TEMP-PLATE to a thickness of 0.002 to 0.004 inch (0.0508 to 0.1016 mm).
The coating should totally cover the surface of the TEMP-PLATE and extend approximately 0.250 inch (6.35 mm)
beyond the edges of the TEMP-PLATE.
7.
Cure the epoxy coating as follows:
DO NOT EXPOSE EPOXY COATING TO OIL, GREASE, CLEANING SOLVENTS, OR OTHER
CHEMICALS DURING CURE.
7.1.
Let the epoxy coating to cure at room temperature (60 to 100°F (16 to 38°C)) for a minimum of 6 hours before
helicopter operation. For best results, let epoxy to cure overnight.
7.2.
The epoxy coating total cure time can be accelerated by allowing the epoxy coating to cure at room temperature for
one hour, then place coupling in a temperature controlled oven for one to two hours at a temperature of 150 to 180°F
(66 to 82°C). An alternate source of heat can be used if the temperature does not exceed 180°F (82°C).
412-A-63-10-00-26A-685A-B
Applicable to: ALL
Page 00232-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
NOTE
Following the cure time, the TEMP-PLATE should conform to the contour of the coupling and be free of
lifted edges. Indicating dots on the TEMP-PLATE must remain the original white or light gray with no
partial black discoloration.
7.3.
After curing time, accomplish an adhesion test by pressing a 1 inch (25.4 mm) wide strip of high adhesion tape over
each TEMP-PLATE and beyond the edge of the epoxy overcoat. Grasp one end of the tape and remove the tape
in one abrupt motion. Lifting of the TEMP-PLATE is not permitted and requires replacement of the TEMP-PLATE
(Step 4. through Step 7.).
Applicable to: ALL
412-A-63-10-00-26A-685A-B
ECCN EAR99
28 OCT 2024 Page 00232-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00045-A-001-01
Figure 1. Tail Rotor Drive Quill Assembly (Sheet 1 of 2)
412-A-63-10-00-26A-685A-B
Applicable to: ALL
Page 00232-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00046-A-001-01
Figure 1. Tail Rotor Drive Quill Assembly (Sheet 2 of 2)
Applicable to: ALL
412-A-63-10-00-26A-685A-B
ECCN EAR99
28 OCT 2024 Page 00232-5
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-26A-685A-B
Applicable to: ALL
Page 00232-6 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Tail Rotor Drive Quill (212-040-365-025) - Assembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Wrench Assembly
Bar
Holding Plate Assembly
Pressing Tool
Wrench
T101307
T101333
T101455
T101599
T101600
1
1
1
1
1
Remarks
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Lubricant
Drycleaning solvent
Lockwire
C-015
C-304
C-405
AR
AR
AR
Remarks
Procedure
NOTE
SN: 36020-36999 or 37002-37999 or SN: 38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed:
Refer to 412-A-63-10-00-27A-710A-B / 00238.
1.
Clean all the parts with drycleaning solvent (C-304) and drain.
DO NOT HANDLE UNOILED PARTS WITH BARE HANDS.
2.
Coat all the parts with the same oil used in the transmission.
SHIM PLATE (8, Figure 1) MUST BE INSTALLED ON SAME SLEEVE (10) FROM WHICH REMOVED
OR GEAR BACKLASH WILL PROBABLY BE INCORRECT.
3.
Install the shim plate (8) as follows:
3.1.
Inspect the shim plate (8) and the sleeve (10) for the serial number. If the same serial number is legible on both parts
or if the shim plate was indexed at the time of removal, install the shim plate as outlined in Step 3.2.. If the shim plate
cannot be positively identified, determine the required shim thickness as outlined in Step 3.3..
3.2.
Put a shim plate (8) of correct thickness on the sleeve (10) and install the three screws (9).
3.3.
Determine the required thickness of the shim plate (8) for the sleeve (10) as follows:
3.3.1.
Inspect the sleeve (10) for a reference dimension, which should be metal stamped or vibro-etched on the sleeve
adjacent to the mounting surface for the shim plate (8) Record this dimension and location on the case.
3.3.2.
Measure the thickness of the shim plate (8) and record.
3.3.3.
Subtract the shim plate (8) thickness from the reference dimension noted in Step 3.3.1.. The resulting value must fall
within the minimum/maximum dimensions listed as follows. This is the required value for a plated shim plate.
SHIM
MINIMUM INCH (MM)
MAXIMUM INCH (MM)
Tail Rotor Drive Quill Shim Plate (8)
0.9760 (24.7904)
0.9765 (24.8031)
Applicable to: ALL
412-A-63-10-00-26A-710A-B
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28 OCT 2024 Page 00233-1
BHT-412-CRO
3.4.
Procure a shim plate (8) of the correct dimension determined in Step 3.3.. Install the shim as described in Step 3.2..
DUPLEX BEARING MUST BE A MATCHED SET WITH SAME SERIAL NUMBER ON BOTH
BEARINGS.
4.
Press the duplex bearings (11) into the sleeve (10), face-to-face, by pressing on the outer race with a suitable sleeve.
5.
Press the roller bearing (7) into the sleeve (10) with the bar (T101333) or a suitable sleeve.
6.
Install the retaining ring (6).
MAKE SURE THAT THE OIL HOLE IN THE GEAR IS NOT OBSTRUCTED OR DAMAGE TO THE
GEAR WILL OCCUR.
7.
Make sure that the cork (5) is installed in the gear (4) and that the oil hole, through the wall of the gear immediately
inboard of the cork, is not obstructed.
8.
Support the duplex bearings (11) on the inner race with the pressing tool (T101599) and press the gear (4) into
the bearings.
9.
Lubricate the new packing (15) with the same oil used in the transmission.
10.
Install the packing (15) on the gear (4).
11.
Press the new seal (14) into the bearing retaining nut (13).
12.
Put a new packing (12) in the groove of the bearing retaining nut (13). Hold the sleeve (10), gear down, with the
holding plate assembly (T101455). Lubricate the packing with the same oil used in the transmission and install the
bearing retaining nut. Use the wrench (T101600) and torque the nut 100 to 150 foot-pounds (136 to 203 Nm).
Secure with lockwire (C-405).
13.
Coat the spacer (16) with the same oil used in the transmission and install the spacer between the seal (14) and
the gear (4).
NOTE
A workaid may be fabricated, as shown in Figure 2, to aid the installation of the seal (17, Figure 1).
14.
Install the new seal (17) into the outer coupling (18) seal groove as follows:
14.1.
Apply a light coat of lubricant (C-015) to the outer circumference of the seal (17).
14.2.
Install the seal (17) into the outer coupling (18) seal groove with the lip of the seal toward the internal splines of the
coupling, as shown in Figure 1, Detail B.
NOTE
With the seal (17) partially seated, use the inner coupling (19) as a backup in reverse (Detail B) to fully
seat the outer circumference edge of the seal into the outer coupling (18) seal groove.
14.3.
With the inner coupling (19) as a backup and placed as shown in Detail B, firmly press down (hand pressure only)
on the outer coupling (18), simultaneously tuck the outer circumference edge of the seal (17) with the workaid, or
equivalent, into the outer coupling seal groove.
14.4.
Continue pressing around the seal (17) with the workaid until the seal is fully seated. Remove the inner coupling
(19) from the outer coupling (18).
NOTE
Make sure the inner coupling (19) is the correct size for the tail rotor drive quill; the overall length is 2.070
to 2.080 inches (52.58 to 52.83 mm). The overall length of the coupling for a 42 and 90° gearbox is 1.870
to 1.880 inches (47.50 to 47.75 mm).
15.
Place a small amount of lubricant (C-015) on the internal splines of the outer coupling (18). Insert the inner coupling
(19) into the outer coupling with the small end through the seal (17).
412-A-63-10-00-26A-710A-B
Applicable to: ALL
Page 00233-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
WHILE TORQUING THE INNER COUPLING, MAINTAIN THE VERTICAL AND HORIZONTAL
STABILITY OF THE OUTER COUPLING OR DAMAGE TO THE COUPLING TEETH MAY OCCUR.
16.
Put the couplings on the splined end of the gear (4). Place the special washer (20) on the coupling retaining bolt
(21) and thread into the gear. Hold the outer coupling (18) with the wrench assembly (T101307) and torque the bolt
80 to 100 foot-pounds (108 to 136 Nm).
NOTE
A 1/4-20 UNC threaded bolt may be used to remove the spring retainer (23) from the coupling retaining
bolt (21).
NOTE
To help installation, mark the holes on the spring retainer (23) and do not install the packing (22) until you
obtain the correct alignment.
17.
Place the new packing (22) on the spring retainer (23). Lubricate the packing with the same oil used in the
transmission and insert into the coupling retaining bolt (21). If one hole in the rim of the spring retainer does not
align with a notch of the male inner coupling (19), pull the retainer free of the bolt, rotate 90°, and install. Repeat if
necessary to obtain alignment. When the hole and the notch are aligned, install the lock spring (24) through the hole
in the rim of the retainer and the notch of the coupling. Make sure that the lock spring is fully engaged in the notch.
18.
Extend the outer coupling (18) so that the seal (17) is out against the spherical teeth on the inner coupling (19) and
coat the internal splines of the outer coupling with lubricant (C-015) to 0.12 inch (3.0 mm) in depth over the top of the
spline teeth. A workaid may be fabricated, as shown in Figure 3, to obtain the depth of the lubricant.
19.
Place the boss of plate assembly (26, Figure 1) on the small end of the centering spring (25) and place the large
end of the spring in the spring retainer (23).
20.
Install the retaining ring (27). Refer to Figure 4 for a cutaway view of the installed components.
21.
Turn the holding plate assembly (T101455) with the quill assembly installed.
22.
Install a new packing (3, Figure 1) on the funnel (2). Lubricate the packing with the same oil used in the transmission
and put the funnel in the gear (4). Install the retaining ring (1).
23.
Check the gear (4) for free rotation.
24.
Refer to Figure 5 and apply sealant around the edge of the bearing retaining nut (13, Figure 1) where it joins the
sleeve (10).
25.
The tail rotor drive quill shall be tagged with the date of lubrication and an entry made in the component historical
record, if the quill is to be returned to stock.
26.
When the tail rotor drive quill is installed on the helicopter, an entry shall be made in the helicopter log and the flex
couplings lubrication log maintained as shown in the BHT-412-MM, with the date of lubrication.
Applicable to: ALL
412-A-63-10-00-26A-710A-B
ECCN EAR99
28 OCT 2024 Page 00233-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00045-A-001-01
Figure 1. Tail Rotor Drive Quill Assembly (Sheet 1 of 2)
412-A-63-10-00-26A-710A-B
Applicable to: ALL
Page 00233-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00046-A-001-01
Figure 1. Tail Rotor Drive Quill Assembly (Sheet 2 of 2)
Applicable to: ALL
412-A-63-10-00-26A-710A-B
ECCN EAR99
28 OCT 2024 Page 00233-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00223-A-001-01
Figure 2. Seal (204-040-611) Installation Workaid (Sheet 1 of 1)
412-A-63-10-00-26A-710A-B
Applicable to: ALL
Page 00233-6 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00224-A-001-01
Figure 3. Lubrication of Tail Rotor Driveshaft Coupling Workaid (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-26A-710A-B
ECCN EAR99
28 OCT 2024 Page 00233-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00213-A-001-01
Figure 4. Accessory and Tail Rotor Drive and Sump Assembly - Damage Limits (Sheet 1 of 3)
412-A-63-10-00-26A-710A-B
Applicable to: ALL
Page 00233-8 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00214-A-001-01
Figure 4. Accessory and Tail Rotor Drive and Sump Assembly - Damage Limits (Sheet 2 of 3)
Applicable to: ALL
412-A-63-10-00-26A-710A-B
ECCN EAR99
28 OCT 2024 Page 00233-9
BHT-412-CRO
ICN-412-A-631000-B-97499-01212-A-001-01
Figure 4. Accessory and Tail Rotor Drive and Sump Assembly - Damage Limits (Sheet 3 of 3)
412-A-63-10-00-26A-710A-B
Applicable to: ALL
Page 00233-10 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00225-A-001-01
Figure 5. Sealing Compound and Sealant Application (Sheet 1 of 2)
Applicable to: ALL
412-A-63-10-00-26A-710A-B
ECCN EAR99
28 OCT 2024 Page 00233-11
BHT-412-CRO
ICN-412-A-631000-B-97499-00226-A-001-01
Figure 5. Sealing Compound and Sealant Application (Sheet 2 of 2)
412-A-63-10-00-26A-710A-B
Applicable to: ALL
Page 00233-12 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Tail Rotor Drive Quill (212-040-365-113 AND -135) - Disassembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Wrench
Removal Bar
Bar
Holding Plate Assembly
Wrench
412-240-007-101
T101333
T101334
T101455
T101600
1
1
1
1
1
Remarks
Procedure
1.
Remove the retaining ring (23, Figure 1).
2.
Remove the lock spring (22).
3.
Install a 1/4-20 threaded bolt into the spring retainer (21) and pull on the bolt to withdraw the retainer from the
adapter (17).
4.
Remove the packing (20) from the spring retainer (21). Discard the packing.
5.
Hold the adapter (17) with the wrench (412-240-007-101), position the square adapter through the wrench, and
remove the adapter retaining bolt (19) and the flat washer (18).
6.
Remove the adapter (17) from the gear (5).
7.
Put the quill sleeve (9) in the holding plate assembly (T101455). Remove the bearing retaining nut (13) with the
wrench (T101600). Remove the seal (14) and the packing (12) from the nut. Discard the seal and the packing.
8.
Remove the spacer (16) and the packing (15). Discard the packing.
9.
Press the gear (5) out of the sleeve (9).
10.
Remove the retaining ring (1), funnel (2), and packing (3). Discard the packing.
11.
Remove the cork (4) from the gear (5). Discard the cork.
IN Step 12. AND Step 14., EXERCISE CARE TO PROPERLY POSITION BEARING REMOVAL BAR
ON BEARINGS TO AVOID DAMAGING BEARING OR SLEEVE (9).
12.
Remove the retaining ring (6).
13.
Press the roller bearing (7) out of the sleeve (9) with the removal bar (T101333).
14.
Press the duplex bearings (11) out of the sleeve (9) with the bar (T101334).
15.
Remove the three screws (10) and the shim plate (8). Identify the shim plate with the sleeve serial number for
installation on the same sleeve.
Applicable to: SN: 36020-36999 or 37002-37999 or
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-27A-530A-B
28 OCT 2024 Page 00234-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00027-A-001-01
Figure 1. Tail Rotor Drive Quill Assembly (212-040-365-113 and -135) (Sheet 1 of 1)
412-A-63-10-00-27A-530A-B
Page 00234-2 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Tail Rotor Drive Quill (212-040-365-113 AND -135) - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Corrosion preventive compound
Drycleaning solvent
MEK
Solvent
Clean cloth
C-105
C-304
C-309
C-334
C-516
AR
AR
AR
AR
AR
Remarks
Procedure
1.
Remove the sealant with a plastic scraper and a clean cloth (C-516) moistened with MEK (C-309).
2.
Clean all the quill parts with drycleaning solvent (C-304). Use a soft bristle brush to dislodge stubborn deposits. All
the parts except the bearings may be cleaned with solvent (C-334) by vapor degreasing method.
DO NOT ALLOW BEARINGS TO SPIN WHILE DRYING.
3.
Dry the parts with a clean cloth (C-516) or dry filtered compressed air.
DO NOT HANDLE UNOILED BEARINGS WITH BARE HANDS.
NOTE
Parts treated per the following step may be left covered in indoor storage for approximately 150 hours
without being affected by corrosion.
4.
Coat the bearings with corrosion preventive compound (C-105) immediately after cleaning (BHT-ALL-SPM, Standard
Practices Manuall).
Applicable to: SN: 36020-36999 or 37002-37999 or
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-27A-258A-B
28 OCT 2024 Page 00235-1
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-27A-258A-B
Page 00235-2 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Tail Rotor Drive Quill (212-040-365-113 AND -135) - Inspection
Procedure
NOTE
Quill Wear/Damage Limits: The quill wear limits are provided to show the required fit between the parts.
It is not intended that wear be measured as a required overhaul procedure.
1.
Inspect the quill parts for wear and damage. If there is evidence of wear, measure the parts, as shown in Figure 1.
Wear in excess of the limits shown is not permitted.
2.
Inspect the following parts by magnetic particle inspection (Code M) or fluorescent penetrant inspection (Code
F), as applicable. Demagnetize the parts after the magnetic particle inspection. Refer to Table 2 and the
BHT-ALL-SPM, Standard Practices Manual for the procedure.
Figure 2INDEX NO.
NOMENCLATURE
CODE
5
Gear
M
9
Sleeve
F
16
Spacer
M
17
Adapter
M
Table 2. Magnetic Particle Inspection
PART NUMBER
NOMENCLATURE
ITEM AND FIGURE
SET UP AND MAGNETIZATION CURRENT REQUIREMENTS
212-040-365-113 and -135
Tail Rotor Drive Quill Assembly
Figure 2
212-040-151-101 and 412-040-151-101
Gear
5, Figure 2
SET UP:
Place part over a 0.7-inch (18-mm) diameter central conductor.
Current for primary diameters, magnetize at 2570 amps.
Optional current for secondary diameters, magnetize at 1190 amps.
Omit coil shot.
212-040-156-101
Spacer
16, Figure 2
SET UP:
Place part over a 1.0-inch (25-mm) diameter central conductor.
Current for primary diameters, magnetize at 708 amps.
Omit coil shot.
412-040-624-101
Adapter
17, Figure 2
SET UP:
Place part over a 1.0-inch (25-mm) diameter central conductor.
Current for primary diameters, magnetize at 3530 amps.
Optional current for secondary diameters, magnetize at 2250 amps.
Omit coil shot.
NOTES:
Applicable to: SN: 36020-36999 or 37002-37999 or
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-27A-280A-B
28 OCT 2024 Page 00236-1
BHT-412-CRO
Table 2. Magnetic Particle Inspection (continued)
1. Magnetization currents provided are applicable to magnetic particle inspection apparatus using Direct Current (DC) . If an
Alternating Current (AC) apparatus is used, adjust the current as follows: AC= 0.667 x DC.
2. Ferrous parts requiring magnetic particle inspection that are not addressed in the attached material, are to be inspected in
accordance with the general procedures outlined in ASTM E1444 standard practices (BHT-ALL-SPM, Chapter 6, Standard
Practices Manual).
3. Part numbers listed apply to all successive dash numbers for that component unless otherwise specified.
3.
Inspect the gear (5, Figure 2) for spalled, scuffed, pitted, chipped, or dented teeth and abnormal wear patterns.
4.
Inspect the roller bearing (7) surface for spalling, scoring, pitting, brinelling, and corrosion damage. Any damage that
can be felt with a 0.020-inch (0.51-mm) spherical radius probe is cause for rejection.
5.
Inspect the splines of the gear (5) for pitted, chipped, or excessively worn teeth in accordance with Figure 1.
6.
Inspect the threads on the gear (5, Figure 2) for damage. Any visual damage is not permitted.
7.
Inspect the sleeve (9) in accordance with Figure 3.
8.
Inspect the adapter (17, Figure 2) for chipped, cracked, broken, pitted, or excessively worn spline teeth.
9.
Inspect the duplex bearings (11) for spalling, scoring, pitting, brinelling, and corrosion damage. Inspect the bearings
for cracked or broken retainers and for roughness when rotated. Any damage to the duplex bearings that can be
detected visually or by feel is not permitted.
10.
Inspect the spacer (16) in the seal contact area for roughness and wear. Damage that could result in oil leakage is
not permitted. Inspect the splines for chipped, broken, and worn teeth. Damage that can be detected visually is
not permitted.
11.
Inspect the bearing retaining nut (13) for damaged threads and broken or rounded corners on the tangs. If damage
exists, replace the nut.
12.
Inspect the coupling retaining bolt (19) for damaged threads.
412-A-63-10-00-27A-280A-B
Page 00236-2 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00227-A-002-01
Figure 1. Tail Rotor Drive Quill (212-040-365-113 and -135) - Damage Limits (Sheet 1 of 2)
Applicable to: SN: 36020-36999 or 37002-37999 or
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-27A-280A-B
28 OCT 2024 Page 00236-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00228-A-001-01
Figure 1. Tail Rotor Drive Quill (212-040-365-113 and -135) - Damage Limits (Sheet 2 of 2)
412-A-63-10-00-27A-280A-B
Page 00236-4 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00027-A-001-01
Figure 2. Tail Rotor Drive Quill Assembly (212-040-365-113 and -135) (Sheet 1 of 1)
Applicable to: SN: 36020-36999 or 37002-37999 or
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-27A-280A-B
28 OCT 2024 Page 00236-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00218-A-001-01
Figure 3. Tail Rotor Drive Quill Sleeve - Damage and Wear Limits (Sheet 1 of 4)
412-A-63-10-00-27A-280A-B
Page 00236-6 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00219-A-001-01
Figure 3. Tail Rotor Drive Quill Sleeve - Damage and Wear Limits (Sheet 2 of 4)
Applicable to: SN: 36020-36999 or 37002-37999 or
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-27A-280A-B
28 OCT 2024 Page 00236-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00220-A-001-01
Figure 3. Tail Rotor Drive Quill Sleeve - Damage and Wear Limits (Sheet 3 of 4)
412-A-63-10-00-27A-280A-B
Page 00236-8 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00221-A-001-01
Figure 3. Tail Rotor Drive Quill Sleeve - Damage and Wear Limits (Sheet 4 of 4)
Applicable to: SN: 36020-36999 or 37002-37999 or
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-27A-280A-B
28 OCT 2024 Page 00236-9
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-27A-280A-B
Page 00236-10 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Tail Rotor Drive Quill (212-040-3645-113 AND -135) - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Chemical film material
Cadmium plating solution
Shellac varnish
C-100
C-108
C-211
AR
AR
AR
Remarks
Procedure
1.
Replace all unserviceable parts.
MAKE SURE THAT THE OIL HOLE IN THE GEAR IS NOT OBSTRUCTED OR DAMAGE TO THE
GEAR WILL OCCUR.
2.
Replace the cork (4, Figure 1) in the gear (5) as follows:
2.1.
Use a new No. 9 short cork and install the cork with shellac varnish (C-211) from 1.030 to 1.150 inches (26.16 to
29.21 mm) to the splined end of the gear, as shown in Figure 1,Section A-A.
2.2.
Make sure that the 0.050 to 0.064 inch (1.27 to 1.62 mm) diameter oil hole is not obstructed.
3.
After repair, refinish parts in accordance with the BHT-ALL-SPM, Standard Practices Manual as follows:
3.1.
Aluminum parts: touch up with chemical film material (C-100).
3.2.
Cadmium plated steel parts: treat reworked areas with cadmium plating solution (C-108) (BHT-ALL-SPM, Standard
Practices Manual).
Applicable to: SN: 36020-36999 or 37002-37999 or
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-27A-685A-B
28 OCT 2024 Page 00237-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00027-A-001-01
Figure 1. Tail Rotor Drive Quill Assembly (212-040-365-113 and -135) (Sheet 1 of 1)
412-A-63-10-00-27A-685A-B
Page 00237-2 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Tail Rotor Drive Quill (212-040-365-113 AND -135) - Assembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Wrench
Holding Plate Assembly
Pressing Tool
Wrench
412-240-008-101
T101455
T101599
T101600
1
1
1
1
Remarks
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Drycleaning solvent
Lockwire
C-304
C-405
AR
AR
Remarks
Procedure
1.
Clean all the parts with drycleaning solvent (C-304) and drain.
DO NOT HANDLE UNOILED PARTS WITH BARE HANDS.
2.
Coat all the parts with the same oil used in the transmission.
SAME SHIM PLATE (8, Figure 1) MUST BE INSTALLED ON SAME SLEEVE (9) FROM WHICH
REMOVED OR GEAR BACKLASH WILL PROBABLY BE INCORRECT.
3.
Install the shim plate (8) as follows:
3.1.
Inspect the shim plate (8) and the sleeve (9) for the serial number. If the same serial number is legible on both parts
or if the shim plate was indexed at the time of removal, install the shim plate as outlined in Step 3.2.. If the shim plate
cannot be positively identified, determine the required shim thickness as outlined in Step 3.3..
3.2.
Put a shim plate (8) of the correct thickness on the sleeve (9) and install the three screws (10).
3.3.
Determine the required thickness for the shim plate (8) for the sleeve (9) as follows:
3.3.1.
Inspect the sleeve (9) for the reference dimension, which should be metal stamped or vibro-etched on the sleeve
adjacent to the mounting surface for the shim plate (8). Record this dimension and location on the case.
3.3.2.
Measure the thickness of the shim plate (8) and record.
3.3.3.
Subtract the shim plate (8) thickness from the reference dimension noted in Step 3.3.1.. The resulting value must fall
within the minimum/maximum dimensions listed as follows. This is the required value for a plated shim plate.
3.4.
SHIM
MINIMUM INCH (MM)
MAXIMUM INCH (MM)
Tail Rotor Drive Quill Shim Plate (8)
0.9760 (24.7904)
0.9765 (24.8031)
Procure a shim plate (8) of the correct dimension determined in Step 3.3.. Install the shim as described in Step 3.2..
DUPLEX BEARING MUST BE A MATCHED SET WITH SAME SERIAL NUMBER ON BOTH
BEARINGS.
Applicable to: SN: 36020-36999 or 37002-37999 or
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-27A-710A-B
28 OCT 2024 Page 00238-1
BHT-412-CRO
4.
Press the duplex bearings (11) into the sleeve (9), face-to-face, by pressing on the outer race with a suitable sleeve.
5.
Press the roller bearing (7) into the sleeve (9) with the bar (T101333) or a suitable sleeve.
6.
Install the retaining ring (6).
MAKE SURE THAT THE OIL HOLE IN THE GEAR IS NOT OBSTRUCTED OR DAMAGE TO THE
GEAR WILL OCCUR.
7.
Make sure that the cork (4) is installed in the gear (5) and that the oil hole, through the wall of the gear immediately
inboard of the cork, is not obstructed.
8.
Support the duplex bearings (11) on the inner race with the pressing tool (T101599) and press the gear (5) into
the bearings.
9.
Lubricate the new packing (15) with the same oil used in the transmission.
10.
Install the packing (15) on the gear (5).
11.
Press the new seal (14) into the bearing retaining nut (13).
12.
Put a new packing (12) in the groove of the bearing retaining nut (13). Hold the sleeve (9), gear down, with the
holding plate assembly (T101455). Lubricate the packing with the same oil used in the transmission and install the
bearing retaining nut. Use the wrench (T101600) and torque the nut 100 to 140 foot-pounds (136 to 190 Nm).
Secure the nut with lockwire (C-405).
13.
Coat the spacer (16) with the same oil used in the transmission and install the spacer between the seal (14) and
the gear (5).
14.
Install the splined end of the adapter (17) on the splined end of the gear (5). Install the flat washer (18) on the
bolt (19) and install in the gear. Hold the adapter with the wrench (412-240-008-101) and torque the bolt 80 to
100 foot-pounds (108 to 136 Nm).
NOTE
A 1/4-20 UNC threaded bolt may be used to remove spring retainer (21) from bolt (19).
NOTE
To help installation, mark the holes on the spring retainer (21) and do not install the packing (20) until you
obtain the correct alignment.
15.
Place the new packing (20) on the spring retainer (21). Lubricate the packing with the same oil used in the
transmission and insert into the coupling retaining bolt (19). If one hole in the rim of the spring retainer does not align
with a notch of the adapter (17), pull the retainer free of the bolt, rotate 90°, and install. Repeat if necessary to obtain
alignment. When the hole and the notch are aligned, install the lock spring (22) through the hole in the rim of the
retainer and notch of the adapter. Make sure that the lock spring is fully engaged in the notch.
16.
Install the retaining ring (23).
17.
Turn the holding plate assembly (T101455) with the quill assembly installed.
18.
Install a new packing (3) on the funnel (2). Lubricate the packing with the same oil used in the transmission and put
the funnel in the gear (5). Install the retaining ring (1).
19.
Check the gear (5) for free rotation.
20.
Refer to Figure 2 and apply sealant around the edge of the bearing retaining nut (13) where it joins the sleeve (9).
412-A-63-10-00-27A-710A-B
Page 00238-2 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00027-A-001-01
Figure 1. Tail Rotor Drive Quill Assembly (212-040-365-113 and -135) (Sheet 1 of 1)
Applicable to: SN: 36020-36999 or 37002-37999 or
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-27A-710A-B
28 OCT 2024 Page 00238-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00225-A-001-01
Figure 2. Sealing Compound and Sealant Application (Sheet 1 of 2)
412-A-63-10-00-27A-710A-B
Page 00238-4 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00226-A-001-01
Figure 2. Sealing Compound and Sealant Application (Sheet 2 of 2)
Applicable to: SN: 36020-36999 or 37002-37999 or
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
412-A-63-10-00-27A-710A-B
28 OCT 2024 Page 00238-5
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-27A-710A-B
Page 00238-6 28 OCT 2024
Applicable to: SN: 36020-36999 or 37002-37999 or
38001-38999 or 39101-39999 or SN: 46400-46499 or
412-570-001-103: Installed or BHT-412-SI-74: Installed
ECCN EAR99
BHT-412-CRO
Single Boost (or System 1) Hydraulic Drive Quill (212-040-365-103) - Disassembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Wrench Assembly
Wrench
Screw Set, 1/4-28 UNF
Bar
Bar
Plate Assembly
T101305
T101306
T101308
T101333
T101334
T101593
1
1
1
1
1
1
Remarks
Procedure
1.
Remove the nuts (1, Figure 1), bolts (18 and 19), and washers (2, 3, 16, 17, 20, and 21).
2.
Remove the cover (4) with the screw set, 1/4-28 unf (T101308). Lightly tap the sprocket (26) as the cover is removed
to prevent binding of the shaft. Remove the gaskets (14 and 22). Discard the gaskets.
3.
Remove the sprocket (26) and the chain (6).
4.
Remove the retaining ring (7) and the sprocket (8).
5.
Cut and remove the lockwire.
6.
Remove the six screws (25), retaining ring (9), and shim (10). Mark the shim for installation on the same quill.
7.
Remove the clip (11).
8.
Install the wrench assembly (T101305) on the nut (12) and hold the gear (33) with the wrench (T101306). Remove
the nut.
9.
Press the gear (33) out of the sleeve (15).
EXERCISE CARE TO AVOID DAMAGING BEARINGS OR SLEEVE WHEN DOING NEXT STEP. MAKE
SURE REMOVAL BARS ARE PROPERLY POSITIONED ON BEARINGS.
10.
Press the duplex bearing (13) out of the sleeve (15) with the bar (T101334). Remove the retaining ring (32).
11.
Press the roller bearing (31) out of the sleeve (15) with the bar (T101333).
12.
Remove the four screws (29) and the shim plate (30). Mark the shim plate for installation on the same sleeve.
13.
Remove the seals (5 and 28) from the cover (4). Discard the seals.
14.
Remove the cork (24) from the sprocket (26). Discard the cork.
15.
Remove the cork (34) from the gear (33). Discard the cork.
16.
Remove the bearings (23 and 27) from the sprocket (26) with the plate assembly (T101593).
Applicable to: ALL
412-A-63-10-00-28A-530A-B
ECCN EAR99
31 MAY 2023 Page 00239-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00026-A-001-01
Figure 1. Single Boost (or System 1) Hydraulic Drive Quill Assembly (Sheet 1 of 1)
412-A-63-10-00-28A-530A-B
Applicable to: ALL
Page 00239-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Single Boost (or System 1) Hydraulic Drive Quill (212-040-365-103) - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Corrosion preventive compound
Drycleaning solvent
MEK
Solvent
Clean cloth
C-105
C-304
C-309
C-334
C-516
AR
AR
AR
AR
AR
Remarks
Procedure
1.
Inspect the quill for corrosion damage to threaded studs and stud holes before cleaning. No structural damage
to threads or holes is permitted.
2.
Remove the sealant from the cover (4, Figure 1) and the sleeve (15) with a plastic scraper and a clean cloth (C-516)
moistened with MEK (C-309).
3.
Clean all quill parts with drycleaning solvent (C-304). Use a soft bristle brush to dislodge stubborn deposits. All the
parts except the bearings may be cleaned with solvent (C-334) by vapor degreasing method.
DO NOT ALLOW BEARINGS TO SPIN WHILE DRYING.
4.
Dry the parts with a clean cloth (C-516) or dry filtered compressed air.
DO NOT HANDLE UNOILED BEARINGS WITH BARE HANDS.
NOTE
Parts treated per the following step may be left covered in indoor storage for approximately 150 hours
without being affected by corrosion.
5.
Coat the bearings with corrosion preventive compound (C-105) immediately after cleaning (BHT-ALL-SPM, Standard
Practices Manual).
Applicable to: ALL
412-A-63-10-00-28A-258A-B
ECCN EAR99
31 MAY 2023 Page 00240-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00026-A-001-01
Figure 1. Single Boost (or System 1) Hydraulic Drive Quill Assembly (Sheet 1 of 1)
412-A-63-10-00-28A-258A-B
Applicable to: ALL
Page 00240-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Single Boost (or System 1) Hydraulic Drive Quill (212-040-365-103) - Inspection
Procedure
NOTE
Quill Wear/Damage Limits: The quill wear limits are provided to show the required fit between the parts.
It is not intended that wear be measured as a required overhaul procedure.
1.
Inspect the quill parts for wear and damage. If there is evidence of wear, measure the parts, as shown in Figure 1.
Wear in excess of the limits shown is not permitted.
2.
Inspect the following parts by magnetic particle inspection (Code M) or fluorescent penetrant inspection (Code
F), as applicable. Demagnetize the parts after the magnetic particle inspection. Refer to Table 2 and the
BHT-ALL-SPM, Standard Practices Manual for the procedure.
Figure 2INDEX NO.
NOMENCLATURE
CODE
4
Cover
F
8
Sprocket
M
12
Nut
M
15
Sleeve
F
26
Sprocket
M
33
Gear
M
Table 2. Magnetic Particle Inspection
PART NUMBER
NOMENCLATURE
ITEM AND FIGURE
SET UP AND MAGNETIZATION CURRENT REQUIREMENTS
212-040-365-103
Hydraulic Drive Quill Assembly
Figure 2
204-040-112-001
Sprocket
8, Figure 2
SET UP:
Place part over a 1.0-inch (25-mm) diameter central conductor.
Current for primary diameters, magnetize at 1030 amps.
Omit coil shot.
204-040-230-001
Nut
12, Figure 2
SET UP:
Place part over a 1.0-inch (25-mm) diameter central conductor
Current for primary diameters, magnetize at 1120 amps.
Omit coil shot.
204-040-333-001
Sprocket
26, Figure 2
SET UP:
Place part over a 0.219-inch (5.56-mm) diameter central conductor.
Current for primary diameters, magnetize at 1509 amps.
Optional current for secondary diameters, magnetize at 452 amps.
Applicable to: ALL
412-A-63-10-00-28A-280A-B
ECCN EAR99
28 OCT 2024 Page 00241-1
BHT-412-CRO
Table 2. Magnetic Particle Inspection (continued)
CONDUCTOR MAY GET HOT.
212-040-149-001
Gear
33, Figure 2
SET UP:
Place part over a 0.5-inch (13-mm) diameter central conductor.
Current for primary diameters, magnetize at 2690 amps.
Optional current for secondary diameters, magnetize at 1310 amps.
CENTRAL CONDUCTOR MAY GET HOT.
Omit coil shot.
NOTES:
1. Magnetization currents provided are applicable to magnetic particle inspection apparatus using Direct Current (DC) . If an
Alternating Current (AC) apparatus is used, adjust the current as follows: AC= 0.667 x DC.
2. Ferrous parts requiring magnetic particle inspection that are not addressed in the attached material, are to be inspected in
accordance with the general procedures outlined in ASTM E1444 standard practices (BHT-ALL-SPM, Chapter 6, Standard
Practices Manual).
3. Part numbers listed apply to all successive dash numbers for that component unless otherwise specified.
3.
Inspect the gear (33) for spalled, scuffed, pitted, chipped, or dented teeth.
4.
Inspect the sprockets (8 and 26, Figure 2) for broken and damaged teeth, and excessive wear. Damage that can be
visually detected is not permitted.
5.
Inspect the chain (6) for wear and elongation. Damage that can be visually detected is not permitted.
6.
Inspect the duplex bearing (13) and ball bearings (23 and 27) for spalling, scoring, pitting, brinelling, corrosion damage,
cracked or broken retainers, and for roughness when rotated. Damage that can be visually detected is not permitted.
7.
Inspect the roller bearing (31) for spalling, scoring, pitting, brinelling, corrosion damage, and cracked or broken roller
retainers. Damage that can be detected with a 0.020-inch (0.51-mm) spherical radius probe is not permitted.
8.
Inspect the sleeve (15) and the cover (4) for corrosion damage and for loose or damaged bearing liners. Inspect the
sleeve for damaged threads and for loose or damaged studs. Superficial mechanical damage is permitted without
repair. Superficial corrosion is permitted if it can be polished out and the area treated for corrosion prevention.
412-A-63-10-00-28A-280A-B
Applicable to: ALL
Page 00241-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00229-A-001-01
Figure 1. Single Boost (or System 1) Hydraulic Drive Quill - Damage Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-28A-280A-B
ECCN EAR99
28 OCT 2024 Page 00241-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00026-A-001-01
Figure 2. Single Boost (or System 1) Hydraulic Drive Quill Assembly (Sheet 1 of 1)
412-A-63-10-00-28A-280A-B
Applicable to: ALL
Page 00241-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Single Boost (or System 1) Hydraulic Drive Quill (212-040-365-103) - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Chemical film material
Cadmium plating solution
Shellac varnish
C-100
C-108
C-211
AR
AR
AR
Remarks
Procedure
1.
Replace all unserviceable parts.
2.
Replace the chain (6, Figure 1) if worn or elongated.
3.
Replace the corks in the gear (33) and the sprocket (26). The gear requires a new No. 12 short cork (34). The
sprocket requires a new No. 1 short cork (24). Install the corks in the position, as shown inFigure 2, with shellac
varnish (C-211).
REPLACE BEARINGS AS A MATCHED SET.
4.
Replace duplex bearings (13, Figure 1) as matched serialized set, if unserviceable.
5.
Repair sleeves that have damaged or loose studs or damaged threads in the jackscrew holes.
6.
Replace the washer seats under the shim plates if loose or missing.
7.
Repair the sleeves that have loose or missing locked-in inserts or studs. Refer to the BHT-ALL-SPM, Standard
Practices Manual for the repair of the studs and the insert outlined in Step 5..
8.
Inspect the sleeve flange top surface for dents and nicks; if damage does not exceed 0.030 inch (0.76 mm) in depth,
polish out damage and blend the repaired area into the flat surface with a minimum radius of 0.12 inch (3.0 mm). The
finished repair must be 63 RHR or better. The maximum depth after repair must not exceed 0.030 inch (0.76 mm).
9.
Refinish the parts after repair in accordance with the BHT-ALL-SPM, Standard Practices Manual as follows:
9.1.
Aluminum parts: touch up with brush chemical film material (C-100).
9.2.
Cadmium plated steel parts: treat reworked areas with cadmium plating solution (C-108) (BHT-ALL-SPM, Standard
Practices Manual).
Applicable to: ALL
412-A-63-10-00-28A-685A-B
ECCN EAR99
31 MAY 2023 Page 00242-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00026-A-001-01
Figure 1. Single Boost (or System 1) Hydraulic Drive Quill Assembly (Sheet 1 of 1)
412-A-63-10-00-28A-685A-B
Applicable to: ALL
Page 00242-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00229-A-001-01
Figure 2. Single Boost (or System 1) Hydraulic Drive Quill - Damage Limits (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-28A-685A-B
ECCN EAR99
31 MAY 2023 Page 00242-3
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-28A-685A-B
Applicable to: ALL
Page 00242-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Single Boost (or System 1) Hydraulic Drive Quill (212-040-365-103) - Assembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Wrench Assembly
Wrench
Bar
Pressing Tool
T101305
T101306
T101333
T101599
1
1
1
1
Remarks
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Drycleaning solvent
Lockwire
C-304
C-405
AR
AR
Remarks
Procedure
1.
Clean all the parts with drycleaning solvent (C-304) and drain.
DO NOT HANDLE UNOILED PARTS WITH BARE HANDS.
2.
Coat all the parts with the same oil used in the transmission.
3.
Install the shim plate (30, Figure 1) as follows:
SHIM PLATE (30) MUST BE INSTALLED ON SAME SLEEVE (15) FROM WHICH REMOVED OR GEAR
BACKLASH WILL PROBABLY BE INCORRECT.
3.1.
Inspect the shim plate (30) and the sleeve (15) for the serial number. If the same serial number is legible on both
parts or if the shim plate was indexed at the time of removal, install the shim plate as outlined in Step 3.2.. If the shim
plate cannot be positively identified, determine the required shim thickness as outlined in Step 3.3..
3.2.
Put the shim plate (30) of the correct thickness on the sleeve (15) and install the four screws (29).
3.3.
Determine the required thickness for the shim plate (30) and the sleeve (15) as follows:
3.3.1.
Inspect the sleeve (15) for the reference dimension, which should be metal stamped or vibro-etched on the sleeve
adjacent to the mounting surface for the shim plate (30). Record this dimension and location on the sleeve.
3.3.2.
Measure the thickness of the shim plate (30) and record.
3.3.3.
Subtract the shim plate thickness from the reference dimension noted in Step 3.3.1.. The resulting value must fall
within the minimum/maximum dimensions listed as follows. This is the required value for a plated shim plate.
3.4.
SHIM
MINIMUM INCH (MM)
MAXIMUM INCH (MM)
Tail Rotor Drive Quill Shim Plate (30)
0.9580 (24.3332)
0.9585 (24.3459)
Procure a shim plate (30) of the correct dimension determined in Step 3.3.. Install the shim as described in Step 3.2..
DUPLEX BEARING MUST BE A MATCHED SET WITH SAME SERIAL NUMBER ON BOTH
BEARINGS.
Applicable to: ALL
412-A-63-10-00-28A-710A-B
ECCN EAR99
31 MAY 2023 Page 00243-1
BHT-412-CRO
4.
Press the duplex bearing (13) into the sleeve (15), face-to-face, by pressing on the outer race with a suitable sleeve.
5.
Press the roller bearing (31) into the sleeve (15) with the bar (T101333) or a suitable sleeve.
6.
Install the retaining ring (32).
WHEN INSTALLING PINION INTO BEARINGS USE CARE TO ONLY APPLY PRESSURE TO THE
PINION HUB AREA. PRESSURE APPLIED AT THE GEAR TEETH CAN RESULT IN CRACKS
BETWEEN THE HOLES IN THE WEB AND POSSIBLE FAILURE OF THE PINION IN SERVICE.
7.
Support the inner races of the duplex bearing (13) with the pressing tool (T101599) and press the gear (33) into
the bearings.
8.
Make sure that the cork (34) is installed in the gear (33).
9.
Install the nut (12) on the gear (33). Hand tighten the nut.
10.
Install the wrench assembly (T101305) on the nut (12) and hold the gear (33) with the wrench (T101306). Torque the
nut with the wrench assembly (T101305) 80 to 100 foot-pounds (108 to 136 Nm).
11.
Install the clip (11).
12.
With a depth micrometer, measure the distance from the outer race of the duplex bearing (13) to the surface on the
sleeve (15) where the retaining ring (9) is to be installed. Record the dimension.
13.
Measure the height of the flange on the retaining ring (9). Record the dimension.
14.
Subtract the sleeve (15) dimension from the retaining ring (9) dimension.
15.
Prepare a shim (10) to provide a 0.003 to 0.006 inch (0.08 to 0.15 mm) pinch fit on the duplex bearing (13).
EXAMPLE:
Ring
0.338 inch (8.585 mm)
Sleeve
-0.302 inch (-7.6708 mm) 0.036 inch (0.9144 mm)
Pinch
-0.003 to 0.003 inch (-0.0762 to 0.0762 mm)
Shim
0.033 to 0.030 inch (0.8382 to 0.7620 mm)
16.
Put the shim (10) and the retaining ring (9) on the sleeve (15) with the notches in the shim aligned with the oil holes
in the ring, and the small hole for the Iockwire in the ring aligned on the centerline between the gear shaft and the
tachometer drive.
17.
Install the six screws (25) and tighten the screws. Secure with lockwire (C-405). Install the Iockwire in accordance
with Figure 1.
18.
Make sure the gear (33) rotates freely.
19.
Put the sprocket (8) on the gear shaft with two projections engaged in the shaft slots.
20.
Install the retaining ring (7).
21.
Make sure that the cork (24) is installed in the sprocket (26).
22.
Press the bearings (23 and 27) on the sprocket (26).
23.
Make sure that the chain (6) spring-lock is properly installed on the connecting link.
24.
Install the chain (6) and the sprocket (26) in the sleeve (15) with the chain on both sprockets and with the bearing (23)
on the short end of the sprocket seated in the sleeve.
25.
Install the new seals (5 and 28) in the cover (4) with the numbered sides of the seals outboard.
26.
Coat the lip of the oil seals (5 and 28) with the same oil used in the transmission.
27.
Put the new gaskets (14 and 22) on the sleeve (15).
412-A-63-10-00-28A-710A-B
Applicable to: ALL
Page 00243-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
28.
Put the cover (4) in position on the sleeve (15).
29.
Install the bolts (18 and 19), with the heads inboard (Figure 1), the steel washers (17 and 20) under the bolt heads,
and the aluminum washers (16 and 21) next to the sleeve (15).
30.
Install the aluminum washers (3), steel washers (2), and nuts (1). Place the aluminum washer next to the cover.
Torque the nuts 50 to 70 inch-pounds (5.65 to 7.91 Nm).
31.
Make sure the gear (33) rotates freely.
Applicable to: ALL
412-A-63-10-00-28A-710A-B
ECCN EAR99
31 MAY 2023 Page 00243-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00026-A-001-01
Figure 1. Single Boost (or System 1) Hydraulic Drive Quill Assembly (Sheet 1 of 1)
412-A-63-10-00-28A-710A-B
Applicable to: ALL
Page 00243-4 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Rotor Brake Drive Quill (412-040-123-101 and -103) - Disassembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Holding Fixture
Plate Assembly
Holding Tool
T101447
T101519
T101649-101
1
1
1
Remarks
Procedure
1.
Install the plate assembly (T101519) in a vise (short studs up) and put the end of the pinion (19, Figure 1) on the plate
assembly (T101519) or hold the brake disc with the holding tool (T101649-101).
2.
Remove the nut (3) and the packing (2). Discard the packing.
3.
If installed, remove the disc (20) from the flange (1) as follows:
3.1.
Cut and remove the lockwire.
3.2.
Hold the disc (20) with the holding fixture (T101447) and remove the bolts (21) and the washers (22).
3.3.
Separate the flange (1) from the disc (20) by hand pressure only.
3.4.
If the disc (20) and the flange (1) cannot be separated by hand pressure, do as follows:
3.4.1.
Install the bolts (21) and the washers (22) to prevent inadvertent assembly separation.
3.4.2.
Put the assembly in an arbor press and remove the bolts (21) and the washers (22).
3.4.3.
Apply sufficient pressure to separate the flange (1) from the disc (20).
3.4.4.
Inspect the disc (20) for warpage (412-A-63-10-00-29A-280A-B / 00246).
4.
Remove the flange (1).
5.
Cut and remove the lockwire.
6.
Remove the bolts (10), washers (11), retainer (8), packing (7), and shim (6). Mark the shim for installation at the same
location and discard the packing.
7.
Remove the transfer tube (16) and the packings (15). Discard the packings.
8.
Press the seal (9) out of the retainer (8). Discard the seal.
9.
Hold the duplex bearings (4) with the plate assembly (T101519) and press the pinion (19) out of the sleeve (13).
10.
Press the bearings (4) and spacer set (5) out of the sleeve (13).
11.
Remove the screws (18) and the shim (17). Identify the shim for installation on the same sleeve.
Applicable to: ALL
412-A-63-10-00-29A-530A-B
ECCN EAR99
31 MAY 2023 Page 00244-1
BHT-412-CRO
ICN-412-A-631000-B-97499-00049-A-001-01
Figure 1. Rotor Brake Drive Quill (Sheet 1 of 1)
412-A-63-10-00-29A-530A-B
Applicable to: ALL
Page 00244-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Rotor Brake Drive Quill (412-040-123-101 and -103) - Cleaning
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Drycleaning solvent
C-304
AR
Remarks
Procedure
1.
Clean the parts with drycleaning solvent (C-304).
2.
Dry the parts with filtered compressed air.
Applicable to: ALL
412-A-63-10-00-29A-258A-B
ECCN EAR99
31 MAY 2023 Page 00245-1
BHT-412-CRO
Intentionally blank page
412-A-63-10-00-29A-258A-B
Applicable to: ALL
Page 00245-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
Rotor Brake Drive Quill (412-040-123-101 and -103) - Inspection
Procedure
1.
Inspect the parts for damage or excessive wear (Figure 1).
2.
Inspect the pinion (19, Figure 2) for chipped, broken, or excessively worn teeth.
3.
Inspect the following parts by magnetic particle inspection (Code M) or fluorescent penetrant inspection (Code
F), as applicable. Demagnetize the parts after the magnetic particle inspection. Refer to Table 2 and the
BHT-ALL-SPM, Standard Practices Manual for the procedure.
Figure 2INDEX NO.
NOMENCLATURE
CODE
1
Flange
M
3
Nut
M
5
Spacer (Outer)
M
5
Spacer (Inner)
M
8
Retainer
F
13
Sleeve
F
19
Pinion
M
20
Disc
M
Table 2. Magnetic Particle Inspection
PART NUMBER
NOMENCLATURE
ITEM AND FIGURE
SET UP AND MAGNETIZATION CURRENT REQUIREMENTS
ROTOR BRAKE DRIVE QUILL (412-040-123-101 AND -103)
209-040-176-101
Spacer Set (two pieces)
5, Figure 2
SET UP:
Place part over a 1-inch (25-mm) diameter central conductor.
Magnetize at 1000 amps, rotate 120°, repeat twice.
Omit coil shot.
412-040-301-101
Pinion
19, Figure 2
SET UP:
Place part over a 0.75-inch (19.1-mm) diameter central conductor.
Magnetize smaller diameter at 1000 amps, rotate 180°, repeat.
Increase current to 2000 amps for larger diameter. Magnetize, inspect, rotate 120°, repeat twice.
SET UP: 5 TURN COIL SHOT:
Place part centrally in coil with long axis extending out of coil.
Apply 10,000 amp-turns (2000 amps).
412-040-177-101
Flange
1, Figure 2
SET UP:
Place part over a 1-inch (25-mm) diameter central conductor.
Magnetize smaller diameter at 1000 amps, rotate 180°, repeat.
Increase current to 1500 amps for larger diameter. Magnetize, inspect, rotate 120°, repeat twice.
Applicable to: ALL
412-A-63-10-00-29A-280A-B
ECCN EAR99
28 OCT 2024 Page 00246-1
BHT-412-CRO
Table 2. Magnetic Particle Inspection (continued)
Omit coil shot.
NOTES:
1. Magnetization currents provided are applicable to magnetic particle inspection apparatus using Direct Current (DC) . If an
Alternating Current (AC) apparatus is used, adjust the current as follows: AC= 0.667 x DC.
2. Ferrous parts requiring magnetic particle inspection that are not addressed in the attached material, are to be inspected in
accordance with the general procedures outlined in ASTM E1444 standard practices (BHT-ALL-SPM, Chapter 6, Standard
Practices Manual).
3. Part numbers listed apply to all successive dash numbers for that component unless otherwise specified.
4.
Inspect the parts dimensionally (Figure 1).
5.
Inspect the shims (6 and 17, Figure 2) for damage and corrosion.
6.
Inspect the inserts (14) for corrosion or damaged threads.
7.
Inspect the pilot hole in the disc (20). The hole diameter must be 2.2478 to 2.2515 inches (57.094 to 57.188 mm).
8.
Inspect the disc (20) for warpage as follows:
8.1.
Install the rotor brake disc inspection arbor (Figure 3) in the pilot hole of the disc (20, Figure 2) and install the four
bolts AN4-5A and the washers AN960-416.
8.2.
Install the arbor and disc assembly between the lathe centers.
8.3.
While rotating the disc (20), measure the runout as indicator probe is swept across full radial width of each friction
surface (front and back).
8.4.
The total indicator runout shall not exceed 0.010 inch (0.25 mm).
8.5.
Measure the rim thickness of the disc (20). The rim thickness shall not be less than 0.422 inch (10.72 mm) at any point.
412-A-63-10-00-29A-280A-B
Applicable to: ALL
Page 00246-2 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00230-A-001-01
Figure 1. Rotor Brake Quill - Wear Limits (Sheet 1 of 2)
Applicable to: ALL
412-A-63-10-00-29A-280A-B
ECCN EAR99
28 OCT 2024 Page 00246-3
BHT-412-CRO
ICN-412-A-631000-B-97499-00231-A-001-01
Figure 1. Rotor Brake Quill - Wear Limits (Sheet 2 of 2)
412-A-63-10-00-29A-280A-B
Applicable to: ALL
Page 00246-4 28 OCT 2024
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00049-A-001-01
Figure 2. Rotor Brake Drive Quill (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-29A-280A-B
ECCN EAR99
28 OCT 2024 Page 00246-5
BHT-412-CRO
ICN-412-A-631000-B-97499-00232-A-002-01
Figure 3. Rotor Brake Disc Inspection Arbor (Sheet 1 of 1)
412-A-63-10-00-29A-280A-B
Applicable to: ALL
Page 00246-6 28 OCT 2024
ECCN EAR99
BHT-412-CRO
Rotor Brake Drive Quill (412-040-123-101 and -103) - Repair
Preliminary requirements
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Chemical film material
Epoxy polyamide primer
MEK
Adhesive
Solvent
Abrasive cloth or paper
India stone
Cheesecloth
C-100
C-204
C-309
C-317
C-334
C-406
C-464
C-486
AR
AR
AR
AR
AR
AR
AR
AR
Remarks
Procedure
1.
If small nicks, burrs, or scratches are visible, dress the splines and the gear teeth with an india stone (C-464).
DUPLEX BEARINGS (4, Figure 1) ARE SERIAL NUMBERED AND SHALL BE INSTALLED IN
MATCHED PAIRS. BOTH BEARINGS OF A PAIR SHALL BE FROM THE SAME MANUFACTURER.
SPACER SET (5) IS FINISH GROUND TOGETHER AND SERIAL NUMBERED AND SHALL BE
REPLACED AS A MATCHED SET.
2.
Replace all unserviceable components.
3.
Replace the shim (17) as follows:
3.1.
Inspect the sleeve (13) for the reference dimension, which is stamped or etched adjacent to the mounting surface.
Record the dimension.
3.2.
Measure a new shim plate thickness and subtract this measurement from the reference dimension recorded from the
sleeve. The result shall be 2.2215 to 2.2220 inches (56.426 to 56.439 mm) after plating.
3.3.
If the resulting dimension is less than 2.2215 inches (56.426 mm), grind the surface of the shim plate to obtain the
proper dimension. After grinding, the surface finish of the shim plate shall be 63 RHR or better.
3.4.
Make sure the screw mounting holes are countersunk. Replate the ground surface of the shim with cadmium
plating (BHT-ALL-SPM, Standard Practices Manual).
4.
Replace the threaded inserts (14) as required (BHT-ALL-SPM, Standard Practices Manual).
5.
Replace the clinch nuts (12) as follows:
5.1.
Use a drift or bolt threaded into the nut to drive the clinch nut (12) out, being careful not to damage the hole in the
sleeve (13) flange.
5.2.
Clean the sleeve (13) by vapor degreasing with solvent (C-334).
5.3.
Clean the surface of the sleeve (13) flange to remove any raised burrs.
5.4.
Treat the hole and any reworked areas on the sleeve with chemical film material (C-100) (BHT-ALL-SPM, Standard
Practices Manual).
5.5.
If the clinch nut (12) was tight before removal, coat a new nut with epoxy polyamide primer (C-204) and drive the clink
nut in place. Remove any raised burrs on the sleeve flange face and touch up with chemical film material (C-100).
Applicable to: ALL
412-A-63-10-00-29A-685A-B
ECCN EAR99
31 MAY 2023 Page 00247-1
BHT-412-CRO
5.6.
If the clinch nut (12) was loose before removal, remove the cadmium plating from the surface of the clinch nut
contacting the sleeve (13) with abrasive cloth or paper (C-406). Clean the clinch nut and the mating surface of the
sleeve with cheesecloth (C-486) moistened with MEK (C-309). Bond the clinch nut in the sleeve with adhesive (C-317).
5.7.
Clean excess adhesive from the threads and the surface of the sleeve (13) flange and the hole. The clinch nut shall
be 0.010 inch (0.25 mm) minimum below the surface of the sleeve flange.
5.8.
Check that the side of the sleeve (13) flange contacting the shim plate is flat and the clinch nut (12) does not protrude
above the surface.
6.
Repair corrosion and damage to the sleeve (13) and the retainer (8) in accordance with Figure 2 and Figure 3.
7.
If surface nicks, burrs, or scratches are visible, dress the splines and threads of the flange (1, Figure 1) with a fine
india stone (C-464). Refer to Figure 4 for the flange rework procedures and limits.
412-A-63-10-00-29A-685A-B
Applicable to: ALL
Page 00247-2 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00049-A-001-01
Figure 1. Rotor Brake Drive Quill (Sheet 1 of 1)
Applicable to: ALL
412-A-63-10-00-29A-685A-B
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31 MAY 2023 Page 00247-3
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ICN-412-A-631000-B-97499-00233-A-001-01
Figure 2. Rotor Brake Quill Sleeve - Rework Limits (Sheet 1 of 3)
412-A-63-10-00-29A-685A-B
Applicable to: ALL
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ICN-412-A-631000-B-97499-00234-A-001-01
Figure 2. Rotor Brake Quill Sleeve - Rework Limits (Sheet 2 of 3)
Applicable to: ALL
412-A-63-10-00-29A-685A-B
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ICN-412-A-631000-B-97499-00235-A-001-01
Figure 2. Rotor Brake Quill Sleeve - Rework Limits (Sheet 3 of 3)
412-A-63-10-00-29A-685A-B
Applicable to: ALL
Page 00247-6 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00236-A-001-01
Figure 3. Rotor Brake Quill Retainer - Rework Limits (Sheet 1 of 2)
Applicable to: ALL
412-A-63-10-00-29A-685A-B
ECCN EAR99
31 MAY 2023 Page 00247-7
BHT-412-CRO
ICN-412-A-631000-B-97499-00237-A-001-01
Figure 3. Rotor Brake Quill Retainer - Rework Limits (Sheet 2 of 2)
412-A-63-10-00-29A-685A-B
Applicable to: ALL
Page 00247-8 31 MAY 2023
ECCN EAR99
BHT-412-CRO
ICN-412-A-631000-B-97499-00238-A-001-01
Figure 4. Rotor Brake Quill Flange - Rework Limits (Sheet 1 of 3)
Applicable to: ALL
412-A-63-10-00-29A-685A-B
ECCN EAR99
31 MAY 2023 Page 00247-9
BHT-412-CRO
ICN-412-A-631000-B-97499-00239-A-001-01
Figure 4. Rotor Brake Quill Flange - Rework Limits (Sheet 2 of 3)
412-A-63-10-00-29A-685A-B
Applicable to: ALL
Page 00247-10 31 MAY 2023
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ICN-412-A-631000-B-97499-00240-A-001-01
Figure 4. Rotor Brake Quill Flange - Rework Limits (Sheet 3 of 3)
Applicable to: ALL
412-A-63-10-00-29A-685A-B
ECCN EAR99
31 MAY 2023 Page 00247-11
BHT-412-CRO
Intentionally blank page
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Applicable to: ALL
Page 00247-12 31 MAY 2023
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Rotor Brake Drive Quill (412-040-123-101 and -103) - Assembly
Preliminary requirements
Support equipment
Nomenclature
Identification No.
Qty
Plate Assembly
T101519
1
Remarks
Consumables, materials and expendables
Nomenclature
Identification No.
Qty
Sealant
Lockwire
C-328
C-405
AR
AR
Remarks
Procedure
1.
Put the duplex bearings (4, Figure 1) in position, back-to-back, on each side of the spacer set (5).
2.
Press the duplex bearings (4) and spacer set (5) in the sleeve (13).
3.
Install the shim (17) plate and the screws (18) on the sleeve (13).
4.
Support the inner race of the duplex bearings (4) with the plate assembly (T101519) or equivalent.
NOTE
When lubricating components, use the same oil used in the transmission.
5.
Lubricate the pinion (19) bearing contact areas with the same oil used in the transmission and press the pinion
in the duplex bearing (4).
6.
Lubricate the new packings (15) with the same oil used in the transmission, and install the packings on the transfer
tube (16), and install the transfer tube in the sleeve (13).
7.
Coat the outside diameter (OD) of the new seal (9) with sealant (C-328) immediately before the installation.
8.
Press the seal (9) in the retainer (8).
NOTE
Maintain a 0.002 to 0.005 inch (0.05 to 0.13 mm) bearing pinch.
9.
Install the retainer (8) without the packing (7) or shim (6) on the sleeve (13). Check the clearance with a feeler gauge
and peel the shim to obtain a 0.002 to 0.005 inch (0.05 to 0.13 mm) bearing pinch.
10.
Lubricate the new packing (7) with the same oil used in the transmission and install the packing in the groove
of the retainer (8).
11.
Install the shim (6) and the retainer (8) on the sleeve (13) with the four bolts (10) and the four washers (11). Torque
the bolts 50 to 70 inch-pounds (5.65 to 7.91 Nm) and secure the bolts in pairs with lockwire (C-405).
12.
Install the flange (1) on the pinion (19).
13.
If previously removed, install the disc (20) on the flange (1) with the washers (22) and the bolts (21). Torque the bolts
50 to 70 inch-pounds (5.65 to 7.91 Nm).
14.
Lubricate the new packing (2) with the same oil used in the transmission, and install the packing on the nut (3), and
install the nut. Torque the nut 125 to 150 foot-pounds (169 to 203 Nm).
15.
Secure the nut (3) between the bolts (21) with lockwire (C-405).
Applicable to: ALL
412-A-63-10-00-29A-710A-B
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BHT-412-CRO
ICN-412-A-631000-B-97499-00049-A-001-01
Figure 1. Rotor Brake Drive Quill (Sheet 1 of 1)
412-A-63-10-00-29A-710A-B
Applicable to: ALL
Page 00248-2 31 MAY 2023
ECCN EAR99
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Transmission Mount Friction Damper - General
This section contains repair and test instructions for the transmission mount friction damper.
Refurbished parts or kits to overhaul the friction dampers can be purchased from LORD Corporation (www.lord.com).
Applicable to: ALL
412-A-63-10-00-05A-028A-B
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Transmission Mount Friction Damper - Inspection
Procedure
1.
Inspect the bearing (1, Figure 1) for wear. The maximum permitted radial play is 0.004 inch (0.10 mm).
2.
Inspect the boot