### 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. 9E991 ECCN: 

## BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET Copyright © 2009 The Boeing Company Unpublished Work - All Rights Reserved Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable subject matter.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.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 1 of 51 2.0BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 2 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT**

BLANK PAGE**Table of Contents** Revision Transmittal Sheet............................................ 5 Summary...................................................... 7 1. PLANNING INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 A. Effectivity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 1. Airplanes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2. Spares Affected. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 B. Concurrent Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 C. Reason. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 D. Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 F. Approval. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 G. Manpower. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 H. Weight and Balance Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 I. Electrical Load Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 J. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 1. Existing Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 2. Data supplied with this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 3. Installation Drawings Used in the Preparation of this Service Bulletin. . . . . . . . . . . . 23 K. Publications Affected. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 L. Interchangeability and Intermixability of Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . 24 2. MATERIAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 A. Material - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 B. Industry Support Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 C. Parts Necessary For Each Airplane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 1. Kits/Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 2. Parts and Materials Supplied by the Operator. . . . . . . . . . . . . . . . . . . . . . . . 25 3. Parts Modified and Reidentified. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 4. Parts Removed and Not Replaced. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 D. Parts Necessary to Change Spares. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 F. Special Tooling Necessary to do this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . 26 3. ACCOMPLISHMENT INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 A. GENERAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 B. WORK INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 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. . . . . . 36 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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 FIGURE 7: LATCH PIN FITTING NO. 1 THRU 8 - BOLT HEAD DIRECTION CHANGE AND TORQUE CHECK. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 3 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 4 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT**

BLANK PAGE

### Commercial **Airplanes** 

# 777 Service Bulletin **ALERT Revision Transmittal Sheet**  **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 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.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 5 of 514. 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, 2009 Original Issue: June 24, 2010 Revision 1:

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 6 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT**

### Commercial **Airplanes** 

# 777 Service Bulletin **ALERT Summary**  **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. **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 - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 7 of 51Boeing 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 - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 8 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT**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 Hours Total Task Hours**  **Airplanes** 1.25 1.25 Group 1 **Terminating Action Elapsed Hours**  **Total Task Hours Airplanes**  1.20 1.20 Group 1
**MATERIAL INFORMATION** Operator Supplied Parts/Materials. Refer to Paragraph 2.A., Material - Price and Availability

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 9 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 10 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT**

### 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.
**DESCRIPTION CONFIGURATION**  **GROUP** 777 airplanes with a forward large cargo door, line numbers 001-825.

- 1

Airplane Models: 777-200, 777-200LR, 777-300, 777-300ER, 777F **Group Variable Number**  1 WA001 - WA017 1 WA076 - WA080 1 WA086 - WA093 1 WA101 - WA104 1 WA116 - WA119 1 WA131 - WA137

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 11 of 51**Group Variable Number**  1 WA171 - WA175 1 WA196 - WA198 1 WA206 - WA212 1 WA221 - WA223 1 WA231 - WA232 1 WA241 - WA250 1 WA261 - WA266 1 WA281 - WA283 1 WA301 - WA304 1 WB001 - WB021 1 WB031 - WB046 1 WB051 - WB088 1 WB101 - WB106 1 WB121 - WB125 1 WB131 - WB148 1 WB151 - WB155 1 WB161 - WB177 1 WB181 - WB194 1 WB201 - WB215 1 WB231 - WB247 1 WB271 - WB273 1 WB276 - WB286 1 WB291 - WB302 1 WB306 - WB307 1 WB311 - WB337 1 WB341 - WB342 1 WB366 - WB368 1 WB371 - WB388 1 WB406 1 WB411 - WB413 1 WB416 - WB439 1 WB446 - WB453 1 WB476

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 12 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT Group**  **Variable Number** 1 WB481 - WB484 1 WB501 - WB512 1 WB531 - WB537 1 WB551 - WB554 1 WB591 - WB597 1 WB601 - WB606 1 WB611 - WB622 1 WB631 - WB638 1 WB646 - WB649 1 WC051 - WC073 1 WC101 - WC104 1 WC111 - WC120 1 WC221 - WC222 1 WC241 - WC243 1 WC281 - WC290 1 WC301 - WC308 1 WC361 - WC364 1 WC371 - WC374 1 WC381 - WC395 1 WC441 1 WC446 - WC449 1 WC456 - WC459 1 WC486 - WC493 1 WC506 - WC508 1 WC521 - WC522 1 WC531 - WC536 1 WC546 - WC548 1 WC556 1 WC566 - WC567 1 WC571 - WC574 1 WD001 - WD002 1 WD011 - WD018 1 WD031 - WD036

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 13 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT Group**  **Variable Number** 1 WD046 - WD055 1 WD066 - WD073 1 WD081 - WD083 1 WD501 - WD513 1 WD521 - WD541 1 WD546 - WD554 1 WD561 - WD573 1 WD581 - WD599 1 WD606 - WD609 1 WD621 - WD632 1 WD651 - WD664 1 WD671 - WD675 1 WD691 - WD709 1 WD741 - WD752 1 WD761 - WD771 1 WD786 - WD788 1 WD796 - WD807 1 WD826 - WD834 1 WD846 - WD858 1 WD871 - WD878 1 WD911 - WD914 1 WD936 - WD939 1 WD946 - WD948 1 WD966 - WD969 1 WD981 - WD982 1 WF001 - WF003 1 WF016 - WF019 1 WF031 - WF032 1 WF046 1 WF076 - WF077 1 WF081 - WF082

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 14 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT**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 777-52A0038 Revision 1: June 24, 2010 15 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT**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.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 16 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT**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 Zone**  **Model** 122 777-200, 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 Time Action**  **Condition**

- Within 12 months after the Revision1 date of this service 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 fractured and/or missing latchpin retention bolts in accordance with Accomplishment Instructions 3.B.2. All airplanes.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 17 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT 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 Time**  **Action Condition** 

- Before further flight. Do terminating action inaccordance with Accomplishment Instructions 3.B.6.No fractured or missing retention bolts and installed bolt head direction is facing inboard. OR Change installed bolthead direction in accordance with Accomplishment Instructions 3.B.2.(a).

- Before further flight. Do terminating action inaccordance with Accomplishment Instructions 3.B.6.No fractured or missing retention bolts and installed bolt head direction is facing outboard. OR Apply a torque to checkfor loose bolts in accordance with Accomplishment Instructions 3.B.2.(a).

- - No further action re- quired.Terminating action accomplished. 1,000 flight cycles. (a) Within 1,000 flight cycles after the previous inspectionin this service 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 fractured, loose and/or missing latch pin retention bolts in accordance withAccomplishment Instructions 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 inaccordance with Accomplishment 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.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 18 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT 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 Time**  **Action Condition** 

- Before further flight.Measure the linear distance between the LPF and latch pin forward/aft end to determine if thepin has migrated in accordance with Accomplishment 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 theengaged or disengaged direction.

- Proceed in accor- dance with Table 3. Proceed in accordance with Table 3. Any missing retention boltand the latch pin did migrate more than the specified distance in the engaged or disengaged direction. (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 Time Action**  **Condition**

- Before further flight. Do a Detailed Inspectionof the LPF latch pin retention bolt hole for anycrack or surface depression in accordance withAccomplishment Instructions 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 theengaged or disengaged direction.

- Before further flight.Replace the LPF in accordance with Accomplishment Instructions 3.B.5,or contact Boeing for repair data and do the repair.Any crack or surface depression found.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 19 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT Table 2: Latch Pin Fitting (LPF) No. 1 through 8 - LPF Inspection - Fitting and Retention Bolt Re**  **placement Repeat Interval**  **(Not to Exceed) Compliance Time**  **Action Condition** 

- Before further flight. Do terminating action inaccordance with Accomplishment Instructions 3.B.6.No crack(s) or surface depression(s) found OR new LPF installed. OR Install new bolt and, change existing installed bolt head direction or, ifbolt head direction is unchanged check for loose bolts in accordance withAccomplishment Instructions 3.B.5.

- - No further action re- quired.Terminating action accomplished. 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 fractured, loose and/or missing latch pin retention bolts in accordance withAccomplishment Instructions 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 Time Action**  **Condition**

- Before further flight. Do a Detailed Inspection of the cargo door main cam latch for any cut, crack or other damage inaccordance with Accomplishment Instructions 3.B.4.(b). Any missing retention boltand the latch pin did migrate in to the cargo door main cam latch more than the specified distance in the engaged direction.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 20 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT 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 Time**  **Action Condition** 

- Before further flight. Proceed in accordancewith Accomplishment Instructions 3.B.5. No cut, crack or other damage found in the cam latch.

- Before further flight. Replace the cargo doormain cam latch in accordance with Accomplishment Instructions 3.B.4.(b). Any cut, crack or other damage found in the cam latch.

- Before further flight. Do a Detailed Inspectionfor 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 latchmechanisms in accordance with Accomplishment 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 accordancewith Accomplishment Instructions 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 theLPF latch pin retention bolt inspection. Do a Detailed Inspectionfor 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 and main camlatch mechanisms in accordance with Accomplishment Instructions 3.B.4.(d).

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 21 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT 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 Hours**  **Task Hours Number of Per-**  **sons Task** 

0.10 0.10 1 Open Access 0.40 0.40 1 Detailed Inspection 0.25 (a) 0.25 (a) 1 Change Installed Bolt Head Direction 0.40 0.40 1 Torque Check 0.10 0.10 1 Close Access 1.25 1.25 TOTAL 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.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 22 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT TERMINATING ACTION**  **Elapsed Hours Task Hours**  **Number of Persons Task**  0.10 0.10 1 Open Access 1.00 1.00 1 Replace Bolts 0.10 0.10 1 Close Access 1.20 1.20 TOTAL 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.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 23 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT Title**  **Drawing Number** LATCH FITTING INSTL - FWD CARGO DOOR PANEL 141W5601 SILL INSTL - LOWER MAIN AND AUXILIARY, FWD CARGO DOOR PANEL 141W5808

**K. Publications Affected** 1. Publications: **Chapter-Section**

**Publication** 52-34 777 Maintenance Manual 52-34 777 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.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 24 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT 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
**Notes Name**  **QTY Part Number /**  **Specification** (a), (b), (d) Bolt 8 BACB30UU3K29 (a), (b), (d) Washer 8 NAS1149E0363P (a), (b), (d) Nut 8 BACN10JC3CD (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.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 25 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT Notes**  **Name QTY**  **Part 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 replacement 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.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 26 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT 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.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 27 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT**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.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 28 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT**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.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1: June 24, 2010 29 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT FIGURE 1: LATCH PIN FITTING NO. 1 THRU 8 - LATCH PIN RETENTION BOLT INSPECTION**  **(SHEET 1 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1 June 24, 2010 30 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT**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)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1 June 24, 2010 31 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** (a) 8

- Bolt Inspect 1 (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)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1 June 24, 2010 32 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT FIGURE 2: LATCH PIN FITTING NO. 1 THRU 8 - LATCH PIN RETENTION BOLT INSTALLATION**  **(SHEET 1 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1 June 24, 2010 33 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT**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)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1 June 24, 2010 34 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** See fastener code table. (a) - - Bolt Install (New) 1
See fastener code table. (a) - - Washer Install (New)
See fastener code table. (a) - - Nut Install (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 DATA HOLE DIA**  **QTY IDENTIFICATION**  **NAME CODE**  (a), (b)

- - BACB30NM3K29 Bolt A Optional substitute. (a), (b) - - BACB30UU3K29 Bolt
Use with BACB30NM3K29. (a) - - NAS1149E0332P Washer
Use with BACB30UU3K29. (a) - - NAS1149E0363P Washer
Use with BACB30NM3K29. (a), (b) - - BACN11Z3CD Nut
Use with BACB30UU3K29. (a), (b) - - BACN10JC3CD Nut (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)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1 June 24, 2010 35 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT**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)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1 June 24, 2010 36 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** (a)

- - Latch Pin Measure 1 (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)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1 June 24, 2010 37 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT FIGURE 4: LATCH PIN FITTING NO. 1 THRU 8 - LATCH PIN FITTING ASSEMBLY REPLACEMENT**  **(SHEET 1 OF 4)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1 June 24, 2010 38 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT**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)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1 June 24, 2010 39 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** 4

- Nut Remove / Keep 1 4

- Washer Remove / Keep 4

- Bolt Remove / Keep 4

- Radius Filler Remove / Keep (a) 1 141W5610-() Latch Assy Remove 2 (b) 1 141W5610-() Latch Assy Install (New) 3 (c) 4

- Radius Filler Install (Kept) (d) 4

- Bolt Install (Kept) 4

- Washer Install (Kept) 4

- Nut Install (Kept) (e)

- - Latch Pin Fitting Adjust 4 (f) 2

- Bolt Torque 5 (g) 2

- Bolt Torque 6 (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)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1 June 24, 2010 40 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT 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 procedure. (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 DATA QTY**  **IDENTIFICATION NAME**  **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 removea bolt and change the installed direction, prior to re-installationthoroughly 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 SOPM20-50-01 as an accepted procedure. - - Bolt 1

**FIGURE 4: LATCH PIN FITTING NO. 1 THRU 8 - LATCH PIN FITTING ASSEMBLY REPLACEMENT (SHEET 4 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1 June 24, 2010 41 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT FIGURE 5: LATCH PIN FITTING NO. 1 THRU 8 - FUSELAGE AND CARGO DOOR INSPECTION**  **(SHEET 1 OF 4)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1 June 24, 2010 42 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT FIGURE 5: LATCH PIN FITTING NO. 1 THRU 8 - FUSELAGE AND CARGO DOOR INSPECTION**  **(SHEET 2 OF 4)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1 June 24, 2010 43 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT**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)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1 June 24, 2010 44 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** (a)

- - Fuselage Inspect 1 (a)

- - Door Inspect 2 (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)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1 June 24, 2010 45 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT FIGURE 6: TERMINATING ACTION - LATCH PIN FITTING NO. 1 THRU 8 - INCONEL BOLT INSTALLATION**  **(SHEET 1 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1 June 24, 2010 46 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT FIGURE 6: TERMINATING ACTION - LATCH PIN FITTING NO. 1 THRU 8 - INCONEL BOLT INSTALLATION**  **(SHEET 2 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1 June 24, 2010 47 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT**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 DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP** 

- 8

- Nut Remove 1

- 8

- Washer Remove

- 8

- Bolt Remove (a) 8 BACB30UU3K29 Bolt Install (New) 2 (a) 8 NAS1149E0363P Washer Install (New) (a) 8 BACN10JC3CD Nut Install (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)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1 June 24, 2010 48 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT FIGURE 7: LATCH PIN FITTING NO. 1 THRU 8 - BOLT HEAD DIRECTION CHANGE AND TORQUE CHECK**  **(SHEET 1 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1 June 24, 2010 49 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT FIGURE 7: LATCH PIN FITTING NO. 1 THRU 8 - BOLT HEAD DIRECTION CHANGE AND TORQUE CHECK**  **(SHEET 2 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1 June 24, 2010 50 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP**  (a)

- - Bolt Change 1 (b)

- - Bolt Torque 2 (b)

- - Bolt Inspect (b)

- - Bolt Torque (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)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 18, 2009 777-52A0038 Revision 1 June 24, 2010 51 of 51 **BOEING SERVICE BULLETIN 777-52A0038 ALERT**  **ALERT**