# Boeing Alert Service Bulletin 777-52A0038: Revision 1

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- Document: [Boeing Alert Service Bulletin 777-52A0038](https://openairdocs.org/service-documents/boeing/777-52a0038.md)
- Title as filed: U.S. DOT/FAA - Service Information
- Pages: 51
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## Text

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### Page 1

Commercial 
Airplanes
777
Service Bulletin
ALERT
Number: 777-52A0038
Original Issue: June 18, 2009
Revision 1: June 24, 2010
ATA System: 5234
SUBJECT: DOORS - Forward Large Cargo Door - Lower Sill Latch Pin Fitting (LPF) No. 1 through
8 - Latch Pin Retention Bolt Inspection
Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15
CFR 730-774). An export license may be required before it is used for development, production or use by foreign
persons from specific countries. The controller of this data has the individual responsibility to abide by all export
laws.
9E991ECCN:
BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET
Copyright © 2009 The Boeing Company
Unpublished Work - All Rights Reserved
Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable
subject matter. Boeing also claims copyright in this document as a compilation and/or collective work.
This document includes proprietary information owned by The Boeing Company and/or one or more third parties.
Treatment of the document and the information it contains is governed by contract with Boeing. For more
information, contact The Boeing Company, P.O. Box 3707, Seattle, Washington 98124.
Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, Dreamliner,
BBJ, DC-8, DC-9, DC-10, KC-10, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8A, Poseidon and the
Boeing livery are all trademarks owned by The Boeing Company; and no trademark license is granted in
connection with this document unless provided in writing by Boeing.
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777-52A0038Revision 1: June 24, 2010
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Table of Contents
Revision Transmittal Sheet ............................................ 5
Summary ...................................................... 7
1. PLANNING INFORMATION ........................................ 1 1
A. Effectivity ............................................... 1 1
1. Airplanes ............................................ 1 1
2. Spares Affected ........................................ 1 5
B. Concurrent Requirements ...................................... 1 5
C. Reason ................................................ 1 5
D. Description .............................................. 1 5
E. Compliance .............................................. 1 7
F. Approval ............................................... 2 2
G. Manpower .............................................. 2 2
H. Weight and Balance Changes .................................... 2 3
I. Electrical Load Data ......................................... 2 3
J. References .............................................. 2 3
1. Existing Data .......................................... 2 3
2. Data supplied with this Service Bulletin ............................ 2 3
3. Installation Drawings Used in the Preparation of this Service Bulletin ............ 2 3
K. Publications Affected ........................................ 2 4
L. Interchangeability and Intermixability of Parts ........................... 2 4
2. MATERIAL INFORMATION ........................................ 2 5
A. Material - Price and Availability ................................... 2 5
B. Industry Support Information .................................... 2 5
C. Parts Necessary For Each Airplane ................................. 2 5
1. Kits/Parts ............................................ 2 5
2. Parts and Materials Supplied by the Operator ........................ 2 5
3. Parts Modified and Reidentified ................................ 2 6
4. Parts Removed and Not Replaced .............................. 2 6
D. Parts Necessary to Change Spares ................................. 2 6
E. Special Tooling - Price and Availability ............................... 2 6
F. Special Tooling Necessary to do this Service Bulletin ....................... 2 6
3. ACCOMPLISHMENT INSTRUCTIONS .................................. 2 7
A. GENERAL INFORMATION ..................................... 2 7
B. WORK INSTRUCTIONS ....................................... 2 7
FIGURE 1: LATCH PIN FITTING NO. 1 THRU 8 - LATCH PIN RETENTION BOLT INSPECTION . . 30
FIGURE 2: LATCH PIN FITTING NO. 1 THRU 8 - LATCH PIN RETENTION BOLT INSTALLATION . 33
FIGURE 3: LATCH PIN FITTING NO. 1 THRU 8 - LATCH PIN MIGRATION INSPECTION ...... 3 6
FIGURE 4: LATCH PIN FITTING NO. 1 THRU 8 - LATCH PIN FITTING ASSEMBLY REPLACEMENT . 38
FIGURE 5: LATCH PIN FITTING NO. 1 THRU 8 - FUSELAGE AND CARGO DOOR INSPECTION . 42
FIGURE 6: TERMINATING ACTION - LATCH PIN FITTING NO. 1 THRU 8 - INCONEL BOLT INSTALLATION
.................................................. 4 6
FIGURE 7: LATCH PIN FITTING NO. 1 THRU 8 - BOLT HEAD DIRECTION CHANGE AND TORQUE
CHECK ............................................. 4 9
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777-52A0038Revision 1: June 24, 2010
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BOEING PROPRIETARY -
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777-52A0038Revision 1: June 24, 2010
4 of 51
BOEING SERVICE BULLETIN 777-52A0038
ALERTALERT
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Commercial 
Airplanes
777
Service Bulletin
ALERT
Revision Transmittal SheetNumber: 777-52A0038Original Issue: June 18, 2009
Revision 1: June 24, 2010
ATA System: 5234
SUBJECT: DOORS - Forward Large Cargo Door - Lower Sill Latch Pin Fitting (LPF) No. 1 through
8 - Latch Pin Retention Bolt Inspection
This revision includes all pages of the service bulletin.
COMPLIANCE INFORMATION RELATED TO THIS REVISION
More work is necessary on airplanes inspected and changed in accordance with the original issue of this service
bulletin. Accomplish terminating action, or alternatively, do repeat Detailed Inspections and torque check for
loose bolts until terminating action is accomplished.
Airplane line numbers 718, 727, 731-734 and 738-825 were added to this service bulletin.
REASON FOR REVISION
This revision is sent to give instruction for a terminating action and to give instruction to do alternative repeat
Detailed Inspections and torque check for loose bolts until the terminating action is accomplished. This revision
is also sent to extend the effectivity of this service bulletin to include all applicable airplanes built before a
production change (equivalent to the terminating action given in this service bulletin) was incorporated.
These sections were changed:
1. Summary Action: Revised text to incorporate terminating action and alternative repeat Detail Inspections
and torque check for loose bolts.
2. Planning Information:
a. 1.D. Description: revised text to incorporate terminating action and alternative repeat Detail Inspections
and torque check for loose bolts.
b. 1.E. Compliance: revised compliance tables to incorporate terminating action and alternative repeat
Detail Inspections and torque check for loose bolts.
c. 1.G. Manpower: added manpower data for the terminating action and change of existing bolt installed
direction.
3. Material Information, 2.C.2. Parts and Materials Supplied by the Operator table: added parts for the
terminating action and Latch Pin Fitting replacement.
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4. Accomplishment Instructions: incorporated instruction for the terminating action, alternative repeat Detail
Inspection and torque check, and revised presentation to clarify the instruction.
5. Figure 1: revised figure step table to clarify work steps.
6. Figure 2: revised figure to add optional bolt part number.
7. Figure 4: revised figure title and revised Latch Pin Fitting replacement step table, added notes and rigging
instructions after a latch pin fitting replacement.
8. Added new Figure 6 to give instruction for the terminating action.
9. Added new Figure 7 to give instruction to change the existing bolt installed direction and torque check for
loose bolts.
Vertical lines are put on the left edge of each page, except in Paragraph 1.A., Effectivity, to show the location
of important changes.
Pages with no vertical lines have no important changes.
REVISION HISTORY
June 18, 2009Original Issue:
June 24, 2010Revision 1:
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777-52A0038Revision 1: June 24, 2010
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BOEING SERVICE BULLETIN 777-52A0038
ALERTALERT

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Commercial 
Airplanes
777
Service Bulletin
ALERT
SummaryNumber: 777-52A0038Original Issue: June 18, 2009
Revision 1: June 24, 2010
ATA System: 5234
SUBJECT: DOORS - Forward Large Cargo Door - Lower Sill Latch Pin Fitting (LPF) No. 1 through
8 - Latch Pin Retention Bolt Inspection
THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH
1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO
THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO
THE NEW OWNER.
CONCURRENT REQUIREMENTS
None.
BACKGROUND
Accomplishment of this service bulletin will inspect the forward large cargo door lower sill Latch Pin Fitting (LPF)
No. 1 through 8 at Station 509.10, 522.75, 537.50, 554.30, 562.90, 579.70, 591.25 and 604.90 for loose, fractured
or missing latch pin retention bolts. A fractured retention bolt can become separated from the LPF and latch pin,
which could lead to migration of the latch pin. A latch pin that migrates and becomes disengaged from the main
cam latch can result in increased loads on adjacent LPFs, which may cause damage to the cargo door latch
mechanism and/or lower sill structure. The migration of two or more latch pins can result in the inability of the
cargo door to carry limit loads which may cause loss of the cargo door and catastrophic depressurization of the
airplane.
The forward large cargo door LPFs are attached to the door lower sill and numbered 1 through 8 forward to aft.
LPFs and latch pins are an integral component of the large forward cargo door latching mechanism that carry
structural and pressurization loads during flight.
Two operators have reported missing and fractured LPF latch pin retention bolts. One report indicated that on
a 777-200 airplane at LPF No. 1 and 2, Stations 509.10 and 522.75, one retention bolt was found on the ground
during closure of the forward cargo door and after further inspection a second bolt was noticed to be missing
from the adjacent fitting. In addition it was found that one of the latch pins had migrated away from engagement
with the corresponding cargo door main cam latch. Based on this report, Boeing requested a limited survey of
the 777 fleet for missing and/or fractured latch pin retention bolts. In response to this request an operator reported
that after applying a 15 in-lb test torque to all eight retention bolts on a 777-300, one retention bolt fractured at
LPF No. 2, Station 522.75. In both cases no further damage was reported as a result of the missing and fractured
retention bolts. All bolts were replaced and the airplanes were returned to normal service.
Boeing has developed terminating action for the Latch Pin Fitting (LPF) latch pin retention bolt inspection and
replacement that was given in the original issue of this service bulletin. In addition, repeat LPF latch pin retention
bolt inspections are added to this revision as optional action for terminating action.
BOEING PROPRIETARY -
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Original Issue: June 18, 2009
777-52A0038Revision 1: June 24, 2010
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### Page 8

Boeing Service Related Problem (SRP) 777-SRP-52-0090 is related to this service bulletin.
ACTION (PRR 62777-68S)
INSPECTION
Do a Detailed Inspection and torque check of the forward large cargo door lower sill Latch Pin Fitting (LPF) No.
1 through 8 at Station 509.10, 522.75, 537.50, 554.30, 562.90, 579.70, 591.25 and 604.90 for loose, fractured
and/or missing latch pin retention bolts.
If no retention bolts are fractured or missing do terminating action, or alternatively, change the installed bolt
head direction of existing bolts if necessary or if bolt head direction is unchanged apply a torque to check for
loose bolts. If no retention bolt is found loose, do repeat Detailed Inspections and torque check for loose bolts.
If any retention bolt is found loose, apply the specified full torque. If any bolt is found fractured during the initial
inspection and has not separated from the LPF and latch pin, carefully remove the bolt and do a Detailed
Inspection of the LPF latch pin retention bolt hole for cracks and/or surface depressions. If no cracks and/or
surface depressions are found do terminating action, or alternatively, install a new retention bolt (same type as
the removed bolt or Inconel bolt.) Do repeat Detailed Inspections and torque check for loose bolts. If any crack
and/or surface depression is found in the LPF, more work is required as specified.
If any retention bolt is missing and the associated latch pin has not migrated more than a specified distance, do
a Detailed Inspection of the LPF latch pin retention bolt hole for cracks and/or surface depressions. If no cracks
and/or surface depressions are found, do terminating action, or alternatively, install a new retention bolt (same
type as the removed bolt or Inconel bolt.) Do repeat Detailed Inspections and torque check for loose bolts. If
any crack and/or surface depression is found in the LPF, more work is required as specified.
If any retention bolt is missing and the associated latch pin has migrated more than a specified distance, do a
Detailed Inspection of the forward large cargo door lower sill, fuselage frames and internal/external skin, cargo
door frames and main cam latch mechanism for damage. If any damage is found remove the associated LPF
and repair the fuselage and/or cargo door in accordance with applicable 777 Structural Repair Manual (SRM)
or contact Boeing for repair data and do the repair. Then do a Detailed Inspection of the LPF latch pin retention
bolt hole for cracks and/or surface depressions. If no cracks and/or surface depressions are found do terminating
action, or alternatively, install a new retention bolt (same type as the missing bolt or Inconel bolt.) Do repeat
Detailed Inspections and torque check for loose bolts. If any crack and/or surface depression is found in the
LPF, more work is required as specified.
TERMINATING ACTION
Terminating action is not complete until titanium bolts have been removed and replaced with new Inconel bolts
at all LPF No. 1 through 8 locations.
To accomplish terminating action, do a Detailed Inspection of LPF No. 1 through 8 for fractured or missing latch
pin retention bolts. If no retention bolts are fractured or missing, remove the existing titanium bolts and replace
with new Inconel bolts. No further action is required. If any existing retention bolt is found fractured and has not
separated from the LPF and latch pin, carefully remove the bolt and do a Detailed Inspection of the LPF latch
pin retention bolt hole for cracks and/or surface depressions. If no cracks and/or surface depressions are found,
replace with a new Inconel bolt. If any crack and/or surface depression is found in the LPF, more work is required
as specified.
If any existing retention bolt is missing and the associated latch pin has not migrated more than a specified
distance, do a Detailed Inspection of the LPF latch pin retention bolt hole for cracks and/or surface depressions.
If no cracks and/or surface depressions are found, replace with a new Inconel bolt. If any crack and/or surface
depression is found in the LPF, more work is required as specified.
BOEING PROPRIETARY -
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Original Issue: June 18, 2009
777-52A0038Revision 1: June 24, 2010
8 of 51
BOEING SERVICE BULLETIN 777-52A0038
ALERTALERT

### Page 9

If any existing retention bolt is missing and the associated latch pin has migrated more than a specified distance,
do a Detailed Inspection of the forward large cargo door lower sill, fuselage frames and internal/external skin,
cargo door frames and main cam latch mechanism for damage. If any damage is found remove the associated
LPF and repair the fuselage and/or cargo door in accordance with applicable 777 Structural Repair Manual
(SRM) or contact Boeing for repair data and do the repair. Then do a Detailed Inspection of the LPF latch pin
retention bolt hole for cracks and/or surface depressions. If no cracks and/or surface depressions are found,
replace with a new Inconel bolt. If any crack and/or surface depression is found in the LPF, more work is required
as specified.
EFFECTIVITY
777-200/-200LR/-300/-300ER/777F Airplanes. Refer to Paragraph 1.A.1., Airplanes for the list of affected
airplanes.
COMPLIANCE
The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to this service
bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin
mandatory.
Refer to Paragraph 1.E., Compliance.
INDUSTRY SUPPORT INFORMATION
Boeing warranty remedies are not available for the inspection and/or repair procedures given in this service
bulletin.
MANPOWER
Inspection
Elapsed HoursTotal Task HoursAirplanes
1.251.25Group 1
Terminating Action
Elapsed HoursTotal Task HoursAirplanes
1.201.20Group 1
MATERIAL INFORMATION
Operator Supplied Parts/Materials.
Refer to Paragraph 2.A., Material - Price and Availability
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BOEING SERVICE BULLETIN 777-52A0038
ALERT  ALERT
HE POSI
NO. 8  NO. 7  NO. 6
NO. 4  NO. 3  NO. 2  NO. 1 |
I DO A DETAILED INSPECTION OF LATCH
PIN FITTING (LPF) NO.1 THROUGH 8
LATCH PIN RETENTION BOLTS FOR
LOOSE, FRACTURED OR MISSING
BOLTS. DO TERMINATING ACTION.  REPLACE ALL LPF RETENTION BOLTS  1743462
WITH NEW INCONEL BOLTS.
FORWARD LARGE CARGO DOOR
Original Issue: June 18, 2009
Revision 1: June 24, 2010  BOEING PROPRIETARY  777-52A0038
Copyright © Unpublished Work - See page 1 for details.  10 of 51

### Page 11

Commercial 
Airplanes
777
Service Bulletin
ALERT
Number: 777-52A0038
Original Issue: June 18, 2009
Revision 1: June 24, 2010
ATA System: 5234
SUBJECT: DOORS - Forward Large Cargo Door - Lower Sill Latch Pin Fitting (LPF) No. 1 through
8 - Latch Pin Retention Bolt Inspection
THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH
1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO
THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO
THE NEW OWNER.
1.    PLANNING INFORMATION
A. Effectivity
1. Airplanes
This service bulletin is for the airplanes shown below.
Refer to Service Bulletin Index Document D624W001 Part 3 for Airplane Variable Number, Line
Number, and Serial Number data.
DESCRIPTIONCONFIGURATIONGROUP
777 airplanes with a forward large cargo door, line numbers 001-825.-1
Airplane Models:
777-200, 777-200LR, 777-300, 777-300ER, 777F
GroupVariable Number
1WA001 - WA017
1WA076 - WA080
1WA086 - WA093
1WA101 - WA104
1WA116 - WA119
1WA131 - WA137
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GroupVariable Number
1WA171 - WA175
1WA196 - WA198
1WA206 - WA212
1WA221 - WA223
1WA231 - WA232
1WA241 - WA250
1WA261 - WA266
1WA281 - WA283
1WA301 - WA304
1WB001 - WB021
1WB031 - WB046
1WB051 - WB088
1WB101 - WB106
1WB121 - WB125
1WB131 - WB148
1WB151 - WB155
1WB161 - WB177
1WB181 - WB194
1WB201 - WB215
1WB231 - WB247
1WB271 - WB273
1WB276 - WB286
1WB291 - WB302
1WB306 - WB307
1WB311 - WB337
1WB341 - WB342
1WB366 - WB368
1WB371 - WB388
1WB406
1WB411 - WB413
1WB416 - WB439
1WB446 - WB453
1WB476
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GroupVariable Number
1WB481 - WB484
1WB501 - WB512
1WB531 - WB537
1WB551 - WB554
1WB591 - WB597
1WB601 - WB606
1WB611 - WB622
1WB631 - WB638
1WB646 - WB649
1WC051 - WC073
1WC101 - WC104
1WC111 - WC120
1WC221 - WC222
1WC241 - WC243
1WC281 - WC290
1WC301 - WC308
1WC361 - WC364
1WC371 - WC374
1WC381 - WC395
1WC441
1WC446 - WC449
1WC456 - WC459
1WC486 - WC493
1WC506 - WC508
1WC521 - WC522
1WC531 - WC536
1WC546 - WC548
1WC556
1WC566 - WC567
1WC571 - WC574
1WD001 - WD002
1WD011 - WD018
1WD031 - WD036
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GroupVariable Number
1WD046 - WD055
1WD066 - WD073
1WD081 - WD083
1WD501 - WD513
1WD521 - WD541
1WD546 - WD554
1WD561 - WD573
1WD581 - WD599
1WD606 - WD609
1WD621 - WD632
1WD651 - WD664
1WD671 - WD675
1WD691 - WD709
1WD741 - WD752
1WD761 - WD771
1WD786 - WD788
1WD796 - WD807
1WD826 - WD834
1WD846 - WD858
1WD871 - WD878
1WD911 - WD914
1WD936 - WD939
1WD946 - WD948
1WD966 - WD969
1WD981 - WD982
1WF001 - WF003
1WF016 - WF019
1WF031 - WF032
1WF046
1WF076 - WF077
1WF081 - WF082
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2. Spares Affected
Examine your spares supply for the parts or components identified in Paragraph 2.C., Parts
Necessary for Each Airplane. If any parts or components are found, refer to Paragraph 2.C. for
the recommended use.
B. Concurrent Requirements
None.
C. Reason
Accomplishment of this service bulletin will inspect the forward large cargo door lower sill Latch Pin
Fitting (LPF) No. 1 through 8 at Station 509.10, 522.75, 537.50, 554.30, 562.90, 579.70, 591.25 and
604.90 for loose, fractured or missing latch pin retention bolts. A fractured retention bolt can become
separated from the LPF and latch pin, which could lead to migration of the latch pin. A latch pin that
migrates and becomes disengaged from the main cam latch can result in increased loads on adjacent
LPFs, which may cause damage to the cargo door latch mechanism and/or lower sill structure. The
migration of two or more latch pins can result in the inability of the cargo door to carry limit loads which
may cause loss of the cargo door and catastrophic depressurization of the airplane.
The forward large cargo door LPFs are attached to the door lower sill and numbered 1 through 8 forward
to aft. LPFs and latch pins are an integral component of the large forward cargo door latching mechanism
that carry structural and pressurization loads during flight.
Two operators have reported missing and fractured LPF latch pin retention bolts. One report indicated
that on a 777-200 airplane at LPF No. 1 and 2, Stations 509.10 and 522.75, one retention bolt was
found on the ground during closure of the forward cargo door and after further inspection a second bolt
was noticed to be missing from the adjacent fitting. In addition it was found that one of the latch pins
had migrated away from engagement with the corresponding cargo door main cam latch. Based on
this report, Boeing requested a limited survey of the 777 fleet for missing and/or fractured latch pin
retention bolts. In response to this request an operator reported that after applying a 15 in-lb test torque
to all eight retention bolts on a 777-300, one retention bolt fractured at LPF No. 2, Station 522.75. In
both cases no further damage was reported as a result of the missing and fractured retention bolts. All
bolts were replaced and the airplanes were returned to normal service.
Boeing has developed terminating action for the Latch Pin Fitting (LPF) latch pin retention bolt inspection
and replacement that was given in the original issue of this service bulletin. In addition, repeat LPF
latch pin retention bolt inspections are added to this revision as optional action for terminating action.
Boeing Service Related Problem (SRP) 777-SRP-52-0090 is related to this service bulletin.
D. Description
INSPECTION
Do a Detailed Inspection and torque check of the forward large cargo door lower sill Latch Pin Fitting
(LPF) No. 1 through 8 at Station 509.10, 522.75, 537.50, 554.30, 562.90, 579.70, 591.25 and 604.90
for loose, fractured and/or missing latch pin retention bolts.
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: June 18, 2009
777-52A0038Revision 1: June 24, 2010
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### Page 16

If no retention bolts are fractured or missing do terminating action, or alternatively, change the installed
bolt head direction of existing bolts if necessary or if bolt head direction is unchanged apply a torque
to check for loose bolts. If no retention bolt is found loose, do repeat Detailed Inspections and torque
check for loose bolts. If any retention bolt is found loose, apply the specified full torque. If any bolt is
found fractured during the initial inspection and has not separated from the LPF and latch pin, carefully
remove the bolt and do a Detailed Inspection of the LPF latch pin retention bolt hole for cracks and/or
surface depressions. If no cracks and/or surface depressions are found do terminating action, or
alternatively, install a new retention bolt (same type as the removed bolt or Inconel bolt.) Do repeat
Detailed Inspections and torque check for loose bolts. If any crack and/or surface depression is found
in the LPF, more work is required as specified.
If any retention bolt is missing and the associated latch pin has not migrated more than a specified
distance, do a Detailed Inspection of the LPF latch pin retention bolt hole for cracks and/or surface
depressions. If no cracks and/or surface depressions are found, do terminating action, or alternatively,
install a new retention bolt (same type as the removed bolt or Inconel bolt.) Do repeat Detailed
Inspections and torque check for loose bolts. If any crack and/or surface depression is found in the
LPF, more work is required as specified.
If any retention bolt is missing and the associated latch pin has migrated more than a specified distance,
do a Detailed Inspection of the forward large cargo door lower sill, fuselage frames and internal/external
skin, cargo door frames and main cam latch mechanism for damage. If any damage is found remove
the associated LPF and repair the fuselage and/or cargo door in accordance with applicable 777
Structural Repair Manual (SRM), Component Maintenance Manual (CMM) or contact Boeing for repair
data and do the repair. Then do a Detailed Inspection of the LPF latch pin retention bolt hole for cracks
and/or surface depressions. If no cracks and/or surface depressions are found do terminating action,
or alternatively, install a new retention bolt (same type as the missing bolt or Inconel bolt.) Do repeat
Detailed Inspections and torque check for loose bolts. If any crack and/or surface depression is found
in the LPF, more work is required as specified.
TERMINATING ACTION
Terminating action is not complete until titanium bolts have been removed and replaced with new
Inconel bolts at all LPF No. 1 through 8 locations.
To accomplish terminating action, do a Detailed Inspection of LPF No. 1 through 8 for fractured or
missing latch pin retention bolts. If no retention bolts are fractured or missing, remove the existing
titanium bolts and replace with new Inconel bolts. No further action is required. If any existing retention
bolt is found fractured and has not separated from the LPF and latch pin, carefully remove the bolt and
do a Detailed Inspection of the LPF latch pin retention bolt hole for cracks and/or surface depressions.
If no cracks and/or surface depressions are found, replace with a new Inconel bolt. If any crack and/or
surface depression is found in the LPF, more work is required as specified.
If any existing retention bolt is missing and the associated latch pin has not migrated more than a
specified distance, do a Detailed Inspection of the LPF latch pin retention bolt hole for cracks and/or
surface depressions. If no cracks and/or surface depressions are found, replace with a new Inconel
bolt. If any crack and/or surface depression is found in the LPF, more work is required as specified.
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If any existing retention bolt is missing and the associated latch pin has migrated more than a specified
distance, do a Detailed Inspection of the forward large cargo door lower sill, fuselage frames and
internal/external skin, cargo door frames and main cam latch mechanism for damage. If any damage
is found remove the associated LPF and repair the fuselage and/or cargo door in accordance with
applicable 777 Structural Repair Manual (SRM), Component Maintenance Manual (CMM) or contact
Boeing for repair data and do the repair. Then do a Detailed Inspection of the LPF latch pin retention
bolt hole for cracks and/or surface depressions. If no cracks and/or surface depressions are found,
replace with a new Inconel bolt. If any crack and/or surface depression is found in the LPF, more work
is required as specified.
Revision 1 is sent to give instruction for a terminating action and to give instruction to do repeat Detailed
Inspections and torque checks until the terminating modification is accomplished. Also, with Revision
1, the effectivity of this service bulletin is extended to include all applicable airplanes built before a
production change (equivalent to the terminating action given in this service bulletin) was incorporated.
The work in this service bulletin is done in the maintenance zone(s) given below.
Affected Maintenance Zones
ZoneModel
122777-200, 777-200LR, 777-300,
777-300ER, 777F
E. Compliance
The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to
this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this
service bulletin mandatory.
Table 1: Forward Large Cargo Door Lower Sill Latch Pin Fitting (LPF) No. 1 through 8 - Retention
Bolt Inspection
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
-Within 12 months
after the Revision
1 date of this ser-
vice bulletin.
At Stations 509.10,
522.75, 537.50, 554.30,
562.90, 579.70, 591.25
and 604.90 do a Detailed
Inspection of the forward
large cargo door lower sill
Latch Pin Fitting (LPF)
No. 1 through 8 for frac-
tured and/or missing latch
pin retention bolts in ac-
cordance with Accom-
plishment Instructions
3.B.2.
All airplanes.
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Table 1: Forward Large Cargo Door Lower Sill Latch Pin Fitting (LPF) No. 1 through 8 - Retention
Bolt Inspection
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
-Before further
flight.
Do terminating action in
accordance with Accom-
plishment Instructions
3.B.6.
No fractured or missing re-
tention bolts and installed
bolt head direction is facing
inboard.
OR
Change installed bolt
head direction in accor-
dance with Accomplish-
ment Instructions
3.B.2.(a).
-Before further
flight.
Do terminating action in
accordance with Accom-
plishment Instructions
3.B.6.
No fractured or missing re-
tention bolts and installed
bolt head direction is facing
outboard.
OR
Apply a torque to check
for loose bolts in accor-
dance with Accomplish-
ment Instructions
3.B.2.(a).
--No further action re-
quired.
Terminating action accom-
plished.
1,000 flight cycles.
(a)
Within 1,000 flight
cycles after the
previous inspection
in this service bul-
letin.
At Stations 509.10,
522.75, 537.50, 554.30,
562.90, 579.70, 591.25
and 604.90 do a Detailed
Inspection of the forward
large cargo door lower sill
Latch Pin Fitting (LPF)
No. 1 through 8 for frac-
tured, loose and/or miss-
ing latch pin retention
bolts in accordance with
Accomplishment Instruc-
tions 3.B.2.
Any existing installed bolt
head direction changed
OR
Any existing installed bolt
head direction not changed
and no loose bolt found or
any loose bolt torqued.
-Proceed in accor-
dance with Table
2.
Remove fractured bolt in
accordance with Accom-
plishment Instruction
3.B.3, then proceed in
accordance with Table 2.
Any retention bolt found
fractured and is engaged
with the LPF and latch pin.
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Table 1: Forward Large Cargo Door Lower Sill Latch Pin Fitting (LPF) No. 1 through 8 - Retention
Bolt Inspection
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
-Before further
flight.
Measure the linear dis-
tance between the LPF
and latch pin forward/aft
end to determine if the
pin has migrated in accor-
dance with Accomplish-
ment Instructions 3.B.4.
Any missing retention bolt.
-Proceed in accor-
dance with Table
2.
Proceed in accordance
with Table 2.
Any missing retention bolt
and the latch pin did not
migrate more than the
specified distance in the
engaged or disengaged di-
rection.
-Proceed in accor-
dance with Table
3.
Proceed in accordance
with Table 3.
Any missing retention bolt
and the latch pin did mi-
grate more than the speci-
fied distance in the en-
gaged or disengaged direc-
tion.
(a) To stop the repeat inspections, do terminating action in accordance with Accomplishment
Instructions 3.B.6.
Table 2: Latch Pin Fitting (LPF) No. 1 through 8 - LPF Inspection - Fitting and Retention Bolt Re-
placement
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
-Before further
flight.
Do a Detailed Inspection
of the LPF latch pin reten-
tion bolt hole for any
crack or surface depres-
sion in accordance with
Accomplishment Instruc-
tions 3.B.5.
Any retention bolt found
fractured and is engaged
with the LPF and latch pin.
Or
Any missing retention bolt
and the latch pin did not
migrate more than the
specified distance in the
engaged or disengaged di-
rection.
-Before further
flight.
Replace the LPF in accor-
dance with Accomplish-
ment Instructions 3.B.5,
or contact Boeing for re-
pair data and do the re-
pair.
Any crack or surface de-
pression found.
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Table 2: Latch Pin Fitting (LPF) No. 1 through 8 - LPF Inspection - Fitting and Retention Bolt Re-
placement
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
-Before further
flight.
Do terminating action in
accordance with Accom-
plishment Instructions
3.B.6.
No crack(s) or surface de-
pression(s) found
OR
new LPF installed.
OR
Install new bolt and,
change existing installed
bolt head direction or, if
bolt head direction is un-
changed check for loose
bolts in accordance with
Accomplishment Instruc-
tions 3.B.5.
--No further action re-
quired.
Terminating action accom-
plished.
1,000 flight cycles.
(a)
Within 1,000 flight
cycles.
At Stations 509.10,
522.75, 537.50, 554.30,
562.90, 579.70, 591.25
and 604.90 do a Detailed
Inspection of the forward
large cargo door lower sill
Latch Pin Fitting (LPF)
No. 1 through 8 for frac-
tured, loose and/or miss-
ing latch pin retention
bolts in accordance with
Accomplishment Instruc-
tions 3.B.2.
New bolt(s) installed
AND
Any existing installed bolt
head direction changed
OR
Any existing installed bolt
head direction not changed
and no loose bolt found or
any loose bolt torqued.
(a) To stop the repeat inspections, do terminating action in accordance with Accomplishment
Instructions 3.B.6.
Table 3: Latch Pin Fitting (LPF) No. 1 through 8 - Latch Pin Migration - Forward Large Cargo Door
Lower Sill and Cargo Door Inspection / Repair
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
-Before further
flight.
Do a Detailed Inspection
of the cargo door main
cam latch for any cut,
crack or other damage in
accordance with Accom-
plishment Instructions
3.B.4.(b).
Any missing retention bolt
and the latch pin did mi-
grate in to the cargo door
main cam latch more than
the specified distance in
the engaged direction.
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Table 3: Latch Pin Fitting (LPF) No. 1 through 8 - Latch Pin Migration - Forward Large Cargo Door
Lower Sill and Cargo Door Inspection / Repair
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
-Before further
flight.
Proceed in accordance
with Accomplishment In-
structions 3.B.5.
No cut, crack or other
damage found in the cam
latch.
-Before further
flight.
Replace the cargo door
main cam latch in accor-
dance with Accomplish-
ment Instructions
3.B.4.(b).
Any cut, crack or other
damage found in the cam
latch.
-Before further
flight.
Do a Detailed Inspection
for cracks or other dam-
age in the forward large
cargo door lower sill,
fuselage frames and inter-
nal/external skin, cargo
door frames, mid-span
latch cam (if installed)
and main cam latch
mechanisms in accor-
dance with Accomplish-
ment Instructions
3.B.4.(c).
Any missing retention bolts
and two or more latch pins
migrated away from the
cargo door main cam latch
more than the specified
distance in the disengaged
direction.
-Before further
flight.
Proceed in accordance
with Accomplishment In-
structions 3.B.5.
Any missing retention bolt
and no more than one latch
pin has migrated away
from the cargo door main
cam latch more than the
specified distance in the
disengaged direction.
-Within 4,000 fight
cycles after the
LPF latch pin reten-
tion bolt inspection.
Do a Detailed Inspection
for cracks or other dam-
age in the forward large
cargo door lower sill,
fuselage frames and inter-
nal/external skin, cargo
door frames, mid-span
latch cam and main cam
latch mechanisms in ac-
cordance with Accom-
plishment Instructions
3.B.4.(d).
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F. Approval
This service bulletin was examined by the Federal Aviation Administration (FAA). The changes specified
in this service bulletin comply with the applicable regulations and are FAA approved, as well as European
Aviation Safety Agency (EASA)/Joint Aviation Authorities (JAA) approved for all EASA/JAA approved
airplanes listed in the service bulletin effectivity. This service bulletin and its approval were based on
the airplane in its original Boeing delivery configuration or as modified by other approved Boeing
changes.
If an airplane has a non-Boeing modification or repair that affects a component or system also affected
by this service bulletin, the operator is responsible for obtaining appropriate regulatory agency approval
before incorporating this service bulletin.
G. Manpower
The table below shows an estimate of the task hours necessary to do this inspection for each airplane.
This estimate is for direct labor only, done by an experienced crew. Adjust the estimate with operator
task hour data if necessary. The estimate does not include lost time. These are some examples of lost
time:
 Time to adjust to the workplace
 Time to schedule the work
 Time to inspect the work
 Time to cure the materials
 Time to make the parts
 Time to find the tools.
INSPECTION/TORQUE CHECK
Elapsed HoursTask HoursNumber of Per-
sons
Task
0.100.101Open Access
0.400.401Detailed Inspection
0.25 (a)0.25 (a)1Change Installed
Bolt Head Direction
0.400.401Torque Check
0.100.101Close Access
1.251.25TOTAL FOR EACH AIRPLANE
NOTE: More work will be required if bolts are fractured, loose and/or missing, or
if damage is found in the Latch Pin Fitting (LPF), forward large cargo door lower
sill, fuselage frames and internal/external skin, cargo door frames, mid-span latch
cam (if installed) or main cam latch mechanisms.
(a) Time is estimated for one bolt change.
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TERMINATING ACTION
Elapsed HoursTask HoursNumber of PersonsTask
0.100.101Open Access
1.001.001Replace Bolts
0.100.101Close Access
1.201.20TOTAL FOR EACH AIRPLANE
H. Weight and Balance Changes
None.
I. Electrical Load Data
Not changed.
J. References
1. Existing Data
a. Engineering Change Memo PRR 62777-68S
b. Standard Overhaul Practices Manual (SOPM) 20-50-01, 20-50-19
c. 777 Aircraft Maintenance Manual (AMM) 52-34-00, 52-34-15
d. 777-200 Structural Repair Manual (SRM) 51-70-00, 53-10-15
e. 777-300 Structural Repair Manual (SRM) 51-70-00, 53-10-15
f. 777F Structural Repair Manual (SRM) 51-70-00, 53-10-15
g. Service Related Problem (SRP) 777-SRP-52-0090
h. Boeing Parts Standards Document D-590
i. Boeing Drawing 012W6100
2. Data supplied with this Service Bulletin
None.
3. Installation Drawings Used in the Preparation of this Service Bulletin
These drawings were used to prepare this service bulletin. These drawings are not necessary to
make the specified changes, and are not supplied with this service bulletin. These drawings may
not be applicable to all airplane configurations or operators.
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TitleDrawing Number
LATCH FITTING INSTL - FWD CARGO DOOR PANEL141W5601
SILL INSTL - LOWER MAIN AND AUXILIARY, FWD CARGO DOOR
PANEL
141W5808
K. Publications Affected
1. Publications:
Chapter-SectionPublication
52-34777 Maintenance Manual
52-34777 Illustrated Parts Catalog
2. Damage Tolerance Based Structural Inspections:
Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue
Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the
Maintenance Program. This service bulletin affects FCS but no new DTIs are necessary.
L. Interchangeability and Intermixability of Parts
Refer to Paragraph 2.C., Parts Necessary for Each Airplane, for interchangeability and intermixability
information.
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2.    MATERIAL INFORMATION
A. Material - Price and Availability
The operator can supply the parts and materials shown in Paragraph 2.C., Parts Necessary for Each
Airplane. As an alternative, operators can purchase the parts from Boeing Spares. This service bulletin
does not show the Boeing price and supply data.
B. Industry Support Information
Boeing warranty remedies are not available for the inspection and/or repair procedures given in this
service bulletin.
C. Parts Necessary For Each Airplane
1. Kits/Parts
None.
2. Parts and Materials Supplied by the Operator
NotesNameQTYPart Number /
Specification
(a), (b), (d)Bolt8BACB30UU3K29
(a), (b), (d)Washer8NAS1149E0363P
(a), (b), (d)Nut8BACN10JC3CD
(a), (b), (e)Bolt-BACB30NM3K29
(a), (b), (e)Washer-NAS1149E0332P
(a), (b), (e)Nut-BACN11Z3CD
(b)Shim (Laminated) 0.062"-141W5613-1
(b)Shim (Laminated) 0.015"-141W5613-15
(b)Shim (Solid) 0.020"-141W5613-20
(b)Shim (Solid) 0.025"-141W5613-25
(b)Shim (Solid) 0.032"-141W5613-32
(b)Shim (Solid) 0.040"-141W5613-40
(b)Shim (Solid) 0.050"-141W5613-50
(b)Shim (Solid) 0.063"-141W5613-63
(c)Corrosion Inhibiting Material-BMS 3-38
(c)Sealant-BMS 5-95, Type I,
Class B
(a) Refer to 777 Structural Repair Manual Chapter 51 for alternate fasteners.
(b) Quantity required is determined at installation.
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NotesNameQTYPart Number /
Specification
(c) See the Qualified Products List (QPL) at the end of the Boeing Material Specification
(BMS) for supplier data.
(d) These parts are to be used for terminating action, and it is allowable to use for replacement
action for repeat Detailed Inspections and torque check.
(e) These parts are NOT to be used for terminating action. It is allowable to use for replace-
ment action for repeat Detailed Inspections and torque check only.
3. Parts Modified and Reidentified
None.
4. Parts Removed and Not Replaced
None.
D. Parts Necessary to Change Spares
None.
E. Special Tooling - Price and Availability
None.
F. Special Tooling Necessary to do this Service Bulletin
No special tools or equipment are necessary to do the change in this service bulletin. But, maintenance
and overhaul tools in the manuals given in Paragraph 1.J., References, can be necessary. Examine
operator tool supply to make sure all necessary tools are available.
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3.    ACCOMPLISHMENT INSTRUCTIONS
A. GENERAL INFORMATION
CAUTION: KEEP THE WORK AREA, WIRES AND ELECTRICAL BUNDLES CLEAN OF METAL
PARTICLES OR CONTAMINATION WHEN YOU USE TOOLS. UNWANTED MATERIAL,
METAL PARTICLES OR CONTAMINATION CAUGHT IN WIRE BUNDLES CAN CAUSE
DAMAGE TO THE BUNDLES. DAMAGED WIRE BUNDLES CAN CAUSE SPARKS OR
OTHER ELECTRICAL DAMAGE.
NOTE: 1. The instructions identified in Paragraph 3.B., Work Instructions and the Figure(s)
give the recommended sequence of steps. The sequence of steps to do this service
bulletin can be changed.
2. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for
definition of the acronyms.
3. Obey all of the warnings and cautions given in the specified manual sections.
4. Unless shown differently, these dimensions and tolerances are used:
– Linear dimensions are in inches
– Angular tolerance is plus or minus 2 degrees
5. Use the approved fastener and process material substitutions in accordance with
777 SRM, Chapter 51. Alternate fasteners are listed in 777 SRM Chapter 51 and
Boeing Drawing 012W6100.
6. If the length of any fastener specified in this service bulletin does not meet the
installation standards in SRM Chapter 51, then a fastener of the same specification,
or an approved substitute, with a length which meets the installation standards in
SRM Chapter 51 may be used.
7. A Detailed Inspection is defined as: An intensive examination of a specific item,
installation, or assembly to detect damage, failure, or irregularity. Available lighting
is normally supplemented with a direct source of good lighting at an intensity deemed
appropriate. Inspection aids such as mirrors, magnifying lenses, etc. may be
necessary. Surface cleaning and elaborate procedures may be required.
8. These work instructions refer to procedures included in other Boeing documents.
When the words "refer to" are used and the operator has an accepted alternative
procedure, the accepted alternative procedure can be used. When the words "in
accordance with" are included in the instruction, the procedure in the Boeing document
must be used.
B. WORK INSTRUCTIONS
1. Open the forward large cargo door. Refer to 777 AMM 52-34-00 as an accepted procedure.
2. At Station 509.10, 522.75, 537.50, 554.30, 562.90, 579.70, 591.25 and 604.90, do a Detailed
Inspection of the forward large cargo door lower sill Latch Pin Fitting (LPF) No. 1 through 8 for
fractured and/or missing latch pin retention bolts in accordance with Figure 1.
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a. If there are no fractured or missing retention bolts, do terminating action in accordance with
paragraph 3.B.6, or alternatively, change the installed bolt head direction of existing latch pin
retention bolts or if bolt head direction is unchanged apply the specified torque to check for
loose bolts in accordance with Figure 7. At the time specified in Paragraph 1.E., Compliance,
do repeat Detailed Inspections and torque to check for loose bolts.
3. If any latch pin retention bolt is found to be fractured and is engaged with the LPF and latch pin,
remove the bolt and then go to paragraph 3.B.5.
4. If any latch pin retention bolt is missing from a LPF and latch pin, DO NOT MOVE THE LATCH
PIN FROM ITS AS FOUND POSITION. Measure the linear distance between the LPF and latch
pin forward/aft end in accordance with Figure 3 to determine if the pin has migrated.
NOTE: Ensure the forward large cargo door lower sill area and cargo door cavities do not contain
Foreign Object Debris (FOD) created by loose or broken bolts.
a. If the latch pin has not migrated or has migrated .03 inch or less in the engaged or disengaged
direction, go to paragraph 3.B.5.
b. If any latch pin has migrated more than .03 inch in to the cargo door main cam latch, engaged
direction, do a Detailed Inspection of the cam for any cut, crack or other damage.
If no cut, crack or other damage is found in the cargo door main cam latch, go to paragraph
3.B.5.
If any cut, crack or other damage is found in the cargo door main cam latch, replace the cam
in accordance with 777 AMM 52-34-15 or contact Boeing for repair data and do the repair,
then go to paragraph 3.B.5.
c. If two or more latch pins have migrated more than .03 inch away from the cargo door main
cam latch, disengaged direction, do a Detailed Inspection for cracks or other damage in the
forward large cargo door lower sill, fuselage frames and internal/external skin, cargo door
frames, mid-span latch cam (if installed) and main cam latch mechanisms in accordance with
Figure 5.
If no cracks or other damage is found in the the forward large cargo door lower sill, fuselage
frames and internal/external skin, cargo door frames, mid-span latch cam and main cam latch
mechanisms, go to paragraph 3.B.5.
If cracks or other damage is found in the forward large cargo door lower sill, fuselage frames
and/or internal/external skin, repair in accordance with 777-200 SRM 53-10-15, 777-300 SRM
53-10-15, 777F SRM 53-10-15 or contact Boeing for repair data and do the repair, then go
to paragraph 3.B.5.
If cracks or other damage is found in the cargo door frames, mid-span latch cam and/or main
cam latch mechanism, repair in accordance with 777-200 SRM 51-70-00, 777-300 SRM
51-70-00, 777F SRM 51-70-00 or contact Boeing for repair data and do the repair, then go
to paragraph 3.B.5.
d. If one latch pin has migrated more than .03 inch away from the cargo door main latch cam,
disengaged direction, go to paragraph 3.B.5. At the time specified in Paragraph 1.E.,
Compliance, do the inspection, and repair if necessary, in accordance with paragraph 3.B.4.c.
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5. Do a Detailed Inspection of the LPF latch pin retention bolt hole for any crack or surface depression.
a. If no crack or surface depression is found, do terminating action in accordance with paragraph
3.B.6, or alternatively, install a new bolt (same type as the removed bolt or Inconel bolt) in
accordance with Figure 2, and change the installed bolt head direction of remaining LPF latch
pin retention bolts or if bolt head direction is unchanged apply the specified torque to check
for loose bolts in accordance with Figure 7. At the time specified in Paragraph 1.E., Compliance,
do repeat Detailed Inspections and torque to check for loose bolts.
b. If any crack and/or surface depression is found, replace the LPF in accordance with Figure
4, or contact Boeing for repair data and do the repair. See Paragraph 1.E., Compliance. Then
do terminating action in accordance with paragraph 3.B.6, or alternatively, install a new bolt
(same type as the removed bolt or Inconel bolt) in accordance with Figure 2, and change the
installed bolt head direction of remaining LPF latch pin retention bolts or if bolt head direction
is unchanged apply a specified torque to check for loose bolts in accordance with Figure 7.
At the time specified in Paragraph 1.E., Compliance, do repeat Detailed Inspections and
torque to check for loose bolts.
6. At Station 509.10, 522.75, 537.50, 554.30, 562.90, 579.70, 591.25 and 604.90, Latch Pin Fitting
(LPF) No. 1 through 8, remove existing titanium latch pin retention bolts and replace with new
Inconel bolts in accordance with Figure 6.
7. Close the forward large cargo door. Refer to 777 AMM 52-34-00 as an accepted procedure.
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BOEING SERVICE BULLETIN 777-52A0038
ALERT  ALERT
FORWARD LARGE CARGO DOOR
NECE
FORWARD LARGE CARGO DOOR
1702762
FIGURE 1: LATCH PIN FITTING NO. 1 THRU 8 - LATCH PIN RETENTION BOLT INSPECTION
(SHEET 1 OF 3)
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### Page 31 (OCR)

BOEING SERVICE BULLETIN 777-52A0038
ALERT  ALERT
NO. 4
NO. 5
NO. 6
NO. 7
END
NO. 8
NO. 1
NO. 2
LATCH PIN
NO. 3  FITTING
LATCH PIN FITTINGS
NUMBERED 1 THROUGH 8, FORWARD TO AFT
LATCH PIN
LATCH PIN FITTING
(TYPICAL)
1702761
The step numbers shown below agree with the numbers shown in the circle symbols in the figure.
FIGURE 1: LATCH PIN FITTING NO. 1 THRU 8 - LATCH PIN RETENTION BOLT INSPECTION
(SHEET 2 OF 3)
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### Page 32

MORE DATAQTYIDENTIFICATIONNAMETASKSTEP
(a)8-BoltInspect1
(a) Do a Detailed Inspection for fractured and/or missing latch pin retention bolts. If any retention bolt is
fractured or missing, more work is required.
FIGURE 1: LATCH PIN FITTING NO. 1 THRU 8 - LATCH PIN RETENTION BOLT INSPECTION
(SHEET 3 OF 3)
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BOEING SERVICE BULLETIN 777-52A0038
ALERTALERT

### Page 33 (OCR)

BOEING SERVICE BULLETIN 777-52A0038
ALERT  ALERT
A FORWARD LARGE CARGO DOOR
PE
FWD
_ FORWARD LARGE CARGO DOOR
1703092
FIGURE 2: LATCH PIN FITTING NO. 1 THRU 8 - LATCH PIN RETENTION BOLT INSTALLATION
(SHEET 1 OF 3)
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### Page 34 (OCR)

BOEING SERVICE BULLETIN 777-52A0038
ALERT  ALERT
NO. 4
NO. 5
NO. 6
NO. 7
TAND
NO. 8
NO. 1
NO. 2
NO. 3
LATCH PIN FITTINGS
NUMBERED 1 THROUGH 8, FORWARD TO AFT  J'
LATCH PIN
LATCH PIN FITTING
(TYPICAL)
1703091
The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for each component.
FIGURE 2: LATCH PIN FITTING NO. 1 THRU 8 - LATCH PIN RETENTION BOLT INSTALLATION
(SHEET 2 OF 3)
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### Page 35

MORE DATAQTYIDENTIFICATIONNAMETASKSTEP
See fastener code
table. (a)
--BoltInstall (New)1
See fastener code
table. (a)
--WasherInstall (New)
See fastener code
table. (a)
--NutInstall (New)
(a) Thoroughly apply BMS 3-38 corrosion inhibiting compound to the bolt shank, threads, washer and nut
mating surfaces prior to installation. Ensure new bolt is installed with the head on the LPF outboard side
(nut on the inboard side) as shown. Refer to SOPM 20-50-01 as an accepted procedure.
The codes shown below agree with the letter shown in the upper left corner of the fastener symbols in the figure.
A number in the lower right corner gives the grip length of the fastener. The QTY numbers shown below are the
number of fasteners necessary for this figure.
MORE DATAHOLE DIAQTYIDENTIFICATIONNAMECODE
(a), (b)--BACB30NM3K29BoltA
Optional substitute. (a),
(b)
--BACB30UU3K29Bolt
Use with
BACB30NM3K29. (a)
--NAS1149E0332PWasher
Use with
BACB30UU3K29. (a)
--NAS1149E0363PWasher
Use with
BACB30NM3K29. (a), (b)
--BACN11Z3CDNut
Use with
BACB30UU3K29. (a), (b)
--BACN10JC3CDNut
(a) Quantity required is determined at installation.
(b) Torque nut or bolt head side to 23-27 in-lbs, target 25 in-lbs.
FIGURE 2: LATCH PIN FITTING NO. 1 THRU 8 - LATCH PIN RETENTION BOLT INSTALLATION
(SHEET 3 OF 3)
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BOEING SERVICE BULLETIN 777-52A0038
ALERTALERT

### Page 36 (OCR)

BOEING SERVICE BULLETIN 777-52A0038
ALERT  ALERT
1.06 MAXIMUM
ENGAGEMENT
1.03 ÷ 0.03
1.00 MINIMUM
ENGAGEMENT
- MEASURE LATCH PIN
MIGRATION FROM
THIS SURFACE
•
DISENGAGED  • ENGAGED
DIRECTION  DIRECTION
•
LATCH PIN
LATCH PIN FITTING
1703245
The step numbers shown below agree with the numbers shown in the circle symbols in the figure.
FIGURE 3: LATCH PIN FITTING NO. 1 THRU 8 - LATCH PIN MIGRATION INSPECTION
(SHEET 1 OF 2)
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### Page 37

MORE DATAQTYIDENTIFICATIONNAMETASKSTEP
(a)--Latch PinMeasure1
(a) Measure the linear distance between the LPF and latch pin forward/aft ends to determine pin migration.
Maximum 0.03 inch migration allowed in the engaged or disengaged direction. Proceed in accordance
with the instructions given in this service bulletin.
FIGURE 3: LATCH PIN FITTING NO. 1 THRU 8 - LATCH PIN MIGRATION INSPECTION
(SHEET 2 OF 2)
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BOEING SERVICE BULLETIN 777-52A0038
ALERTALERT

### Page 38 (OCR)

BOEING SERVICE BULLETIN 777-52A0038
ALERT  ALERT
A FORWARD LARGE CARGO DOOR
FWD
FORWARD LARGE CARGO DOOR
FIGURE 4: LATCH PIN FITTING NO. 1 THRU 8 - LATCH PIN FITTING ASSEMBLY REPLACEMENT
(SHEET 1 OF 4)
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### Page 39 (OCR)

BOEING SERVICE BULLETIN 777-52A0038
ALERT  ALERT
NO. 4
NO. 5
NO. 6
NO. 7
NO. 1
NO. 8
NO. 2
NO. 3
LATCH PIN FITTINGS
NUMBERED 1 THROUGH 8, FORWARD TO AFT
NBD
B-B  A-A  1723038
LATCH PIN FITTING
(TYPICAL)
The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for each component.
FIGURE 4: LATCH PIN FITTING NO. 1 THRU 8 - LATCH PIN FITTING ASSEMBLY REPLACEMENT
(SHEET 2 OF 4)
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### Page 40

MORE DATAQTYIDENTIFICATIONNAMETASKSTEP
4-NutRemove / Keep1
4-WasherRemove / Keep
4-BoltRemove / Keep
4-Radius FillerRemove / Keep
(a)1141W5610-()Latch AssyRemove2
(b)1141W5610-()Latch AssyInstall (New)3
(c)4-Radius FillerInstall (Kept)
(d)4-BoltInstall (Kept)
4-WasherInstall (Kept)
4-NutInstall (Kept)
(e)--Latch Pin FittingAdjust4
(f)2-BoltTorque5
(g)2-BoltTorque6
(a) Mark the position of the existing latch pin fitting in relation to the serrated plate on the lower sill to facilitate
new Latch Pin Fitting installation.
(b) Ensure existing shim stack-up is maintained. Use existing shim(s) for adjustment and installation. If shim(s)
become damaged and unusable or thickness adjustments must be made, replace with new shims. Refer
to Paragraph 2.C.2, Parts and Materials Supplied by the Operator for a list of replacement parts.
(c) Apply BMS5-95 sealant to fay surfaces. Refer to SOPM 20-50-19 as an accepted procedure.
(d) Install bolts wet with BMS5-95 sealant. Refer to SOPM 20-50-19 Method 2 as an accepted procedure.
Do not apply full torque at this step.
(e) Adjust the Latch Pin Fitting(s) and cargo door rigging as necessary. Refer to TABLE 1 in this figure as an
accepted procedure.
(f) Torque from head-side 620-760 in-lb, target 690 in-lb.
(g) Torque from head-side 1320-1620 in-lb, target 1470 in-lb.
The following table describes the airplane condition and necessary Latch Pin Fitting adjustments and cargo door
rigging procedures to be accomplished during a Latch Pin Fitting replacement. Refer to 777 AMM 52-34-00 for
any special tools required to facilitate the work.
FIGURE 4: LATCH PIN FITTING NO. 1 THRU 8 - LATCH PIN FITTING ASSEMBLY REPLACEMENT
(SHEET 3 OF 4)
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BOEING SERVICE BULLETIN 777-52A0038
ALERTALERT

### Page 41

TABLE 1
LATCH PIN FITTING/CARGO DOOR ADJUSTMENT
1. Do cargo door rigging procedures with the airplane in the following condition: Operating weight empty
and the airplane supported on its landing gear and stabilized with jacks. To prevent unwanted structural
deflections, limit all stabilizing jack loads to 5,000 lbs. maximum.
2. Do the following Installation Rigging adjustments. Refer to 777 AMM 52-34-00 as an accepted proce-
dure.
(a) Lift Mechanism Adjustment
(b) Centering Roller Adjustment
(c) Pull-In Hook and Pin Adjustment
(d) Main Latch Adjustment
3. Do the following Sensor Rigging adjustments. Refer to 777 AMM 52-34-00 as an accepted procedure.
(a) Door Control Proximity Sensor Adjustment
(b) Door Indication Proximity Sensor Adjustment
The flag note numbers shown below agree with the numbers shown in the flag symbols in the figure.
MORE DATAQTYIDENTIFICATIONNAME
FLAG
NOTE
Ensure bolt is installed with the
head on the LPF outboard side
(nut on the inboard side) as
shown. If it is necessary to remove
a bolt and change the installed di-
rection, prior to re-installation
thoroughly apply BMS 3-38 corro-
sion inhibiting compound to the
bolt shank, threads, washer and
nut mating surfaces. Torque nut
or bolt head side to 23-27 in-lbs,
target 25 in-lbs. Refer to SOPM
20-50-01 as an accepted proce-
dure.
--Bolt1
FIGURE 4: LATCH PIN FITTING NO. 1 THRU 8 - LATCH PIN FITTING ASSEMBLY REPLACEMENT
(SHEET 4 OF 4)
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BOEING SERVICE BULLETIN 777-52A0038
ALERTALERT

### Page 42 (OCR)

BOEING SERVICE BULLETIN 777-52A0038
ALERT  ALERT
FORWARD
LARGE CARGO C
DOOR
AND B
LATCH PIN LOCATION
42.00
RBL
23
42.00
'STA
613
TYPICAL FORWARD LARGE CARGO
DOOR LOWER SILL AREA
508  STA  1727755
FIGURE 5: LATCH PIN FITTING NO. 1 THRU 8 - FUSELAGE AND CARGO DOOR INSPECTION
(SHEET 1 OF 4)
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### Page 43

FIGURE 5: LATCH PIN FITTING NO. 1 THRU 8 - FUSELAGE AND CARGO DOOR INSPECTION
(SHEET 2 OF 4)
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BOEING SERVICE BULLETIN 777-52A0038
ALERTALERT

### Page 44 (OCR)

BOEING SERVICE BULLETIN 777-52A0038
ALERT  ALERT
FWD
LARGE FORWARD CARGO DOOR
TYPICAL  TYPICAL
(IF INSTALLED)
1727756
The step numbers shown below agree with the numbers shown in the circle symbols in the figure.
FIGURE 5: LATCH PIN FITTING NO. 1 THRU 8 - FUSELAGE AND CARGO DOOR INSPECTION
(SHEET 3 OF 4)
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### Page 45

MORE DATAQTYIDENTIFICATIONNAMETASKSTEP
(a)--FuselageInspect1
(a)--DoorInspect2
(a) Do a Detailed Inspection for cracks or other damage in the forward large cargo door lower sill, fuselage
frames and interior/exterior skin, cargo door frames, mid-span latch cams (if installed) and main cam latch
mechanism. Do the inspection 42.0 inches in the forward, aft and inboard direction from the Latch Pin
Fitting (LPF) with the migrated latch pin. If any damage is found, more work is required.
FIGURE 5: LATCH PIN FITTING NO. 1 THRU 8 - FUSELAGE AND CARGO DOOR INSPECTION
(SHEET 4 OF 4)
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BOEING SERVICE BULLETIN 777-52A0038
ALERTALERT

### Page 46 (OCR)

BOEING SERVICE BULLETIN 777-52A0038
ALERT  ALERT
A FORWARD LARGE CARGO DOOR
FORWARD LARGE CARGO DOOR
1915731
FIGURE 6: TERMINATING ACTION - LATCH PIN FITTING NO. 1 THRU 8-INCONEL BOLTINSTALLATION
(SHEET 1 OF 3)
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### Page 47 (OCR)

BOEING SERVICE BULLETIN 777-52A0038
ALERT  ALERT
NO. 4
NO. 5
NO. 6
NO. 7
END
NO. 8
NO. 1
NO. 2
NO. 3
LATCH PIN FITTINGS
NUMBERED 1 THROUGH 8, FORWARD TO AFT
LATCH PIN FITTING
(TYPICAL)
1915732
FIGURE 6: TERMINATING ACTION - LATCH PIN FITTING NO. 1 THRU 8 - INCONEL BOLT INSTALLATION
(SHEET 2 OF 3)
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### Page 48

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for this figure.
MORE DATAQTYIDENTIFICATIONNAMETASKSTEP
-8-NutRemove1
-8-WasherRemove
-8-BoltRemove
(a)8BACB30UU3K29BoltInstall (New)2
(a)8NAS1149E0363PWasherInstall (New)
(a)8BACN10JC3CDNutInstall (New)
(a) Prior to installation, thoroughly apply BMS 3-38 corrosion inhibiting compound to the bolt shank, threads,
washer and nut mating surfaces. Ensure bolt is installed with the head on the LPF outboard side (nut on
the inboard side) as shown. Torque nut or bolt head side to 23-27 in-lbs, target 25 in-lbs. Refer to SOPM
20-50-01 as an accepted procedure.
FIGURE 6: TERMINATING ACTION - LATCH PIN FITTING NO. 1 THRU 8 - INCONEL BOLT INSTALLATION
(SHEET 3 OF 3)
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BOEING SERVICE BULLETIN 777-52A0038
ALERTALERT

### Page 49 (OCR)

BOEING SERVICE BULLETIN 777-52A0038
ALERT  ALERT
_ FORWARD LARGE CARGO DOOR
FWD
FORWARD LARGE CARGO DOOR
1937411
I FIGURE 7: LATCH PIN FITTING NO. 1 THRU 8 - BOLT HEAD DIRECTION CHANGE AND TORQUE CHECK
(SHEET 1 OF 3)
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### Page 50 (OCR)

BOEING SERVICE BULLETIN 777-52A0038
ALERT  ALERT
NO. 4
NO. 5
NO. 6
NO. 7
TAND
NO. 8
NO. 1
INCORRECT
INSTALLATION
CORRECT
INSTALLATION  NO. 2
NO. 3  LATCH PIN
FITTING
LATCH PIN FITTINGS
NUMBERED 1 THROUGH 8, FORWARD TO AFT
LATCH PIN FITTING
(TYPICAL INCORRECT
INSTALLED DIRECTION)
1937453
_ FIGURE 7: LATCH PIN FITTING NO. 1 THRU 8 - BOLT HEAD DIRECTION CHANGE AND TORQUE CHECK
(SHEET 2 OF 3)
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### Page 51

The step numbers shown below agree with the numbers shown in the circle symbols in the figure.
MORE DATAQTYIDENTIFICATIONNAMETASKSTEP
(a)--BoltChange1
(b)--BoltTorque2
(b)--BoltInspect
(b)--BoltTorque
(a) Change the installed bolt head direction of existing latch pin retention bolts as necessary. Remove any
bolt that is installed with the head on the LPF inboard side (nut on the outboard side) and re-install the
bolt(s) with the head on the LPF outboard side (nut on the inboard side) as shown. Prior to re-installation
thoroughly apply BMS 3-38 corrosion inhibiting compound to the bolt shank, threads, washer and nut
mating surfaces. Torque nut or bolt head side to 23-27 in-lbs, target 25 in-lbs. Refer to SOPM 20-50-01
as an accepted procedure.
(b) At LPF locations where the installed direction was not changed, apply a 13-15 in-lb torque to the head or
nut to check for loose bolts. Any loose bolts found, remove the nut and do a Detailed Inspection of the
nut and bolt to ensure no threads are damaged. If threads are damaged, replace with a new bolt and nut.
Thoroughly apply BMS 3-38 corrosion inhibiting compound to the bolt threads, shank, washer and nut
mating surfaces. Install nut and apply a 23-27 in-lb full torque, target 25 in-lb, to the latch pin retention
bolt head or nut. Refer to SOPM 20-50-01 as an accepted procedure.
FIGURE 7: LATCH PIN FITTING NO. 1 THRU 8 - BOLT HEAD DIRECTION CHANGE AND TORQUE CHECK
(SHEET 3 OF 3)
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BOEING SERVICE BULLETIN 777-52A0038
ALERTALERT

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