### Commercial **Airplanes** 

# 777 Service Bulletin **ALERT Number: 777-57A0090**  Original Issue: August 24, 2011 ATA System: 5754 **SUBJECT:** WINGS - Landing Gear Attach Fittings and Support Beam - Main Landing Gear Forward Trunnion Lower Housing Fuse Pin - Inspection and Replacement 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## BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET Copyright © 2011 The Boeing Company Unpublished Work - All Rights Reserved Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable subject matter.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BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 1 of 37 4.0BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 2 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT**

BLANK PAGE**Table of Contents** Summary...................................................... 5 1. PLANNING INFORMATION ........................................ 9 A. Effectivity................................................ 9 1. Airplanes............................................. 9 2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 B. Concurrent Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 C. Reason. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 H. Weight and Balance Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 I. Electrical Load Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 J. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 1. Existing Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 2. Data supplied with this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3. Installation Drawings Used in the Preparation of this Service Bulletin. . . . . . . . . . . . 17 K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 L. Interchangeability and Intermixability of Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . 18 2. MATERIAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 A. Material - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 C. Parts Necessary For Each Airplane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 1. Kits/Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 2. Parts and Materials Supplied by the Operator. . . . . . . . . . . . . . . . . . . . . . . . 20 3. Parts Modified and Reidentified. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 4. Parts Removed and Not Replaced. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 D. Parts Necessary to Change Spares. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 F. Special Tooling Necessary to do this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . 22 3. ACCOMPLISHMENT INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 A. GENERAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 B. WORK INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 FIGURE 1: LEFTMLG FORWARD TRUNNION LOWER HOUSING FUSE PIN CROSS BOLT INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 FIGURE 2: RIGHT MLG FORWARD TRUNNION LOWER HOUSING FUSE PIN CROSS BOLT INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 FIGURE 3: LEFT MLG FORWARD TRUNNION UPPER AND LOWER HOUSING FUSE PIN REPLACEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 FIGURE 4: RIGHT MLG FORWARD TRUNNION UPPER AND LOWER HOUSING FUSE PIN REPLACEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 3 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 4 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT**

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### Commercial **Airplanes** 

# 777 Service Bulletin **ALERT Summary**  **Number: 777-57A0090** Original Issue: August 24, 2011 ATA System: 5754 **SUBJECT:** WINGS - Landing Gear Attach Fittings and Support Beam - Main Landing Gear Forward Trunnion Lower Housing Fuse Pin - Inspection and Replacement 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 make sure the Main Landing Gear (MLG) Forward Trunnion Lower Housing fuse pins and related cross bolts are correctly installed. An incorrectly installed fuse pin and cross bolt could result in migration of the fuse pin from the MLG Forward Trunnion Lower Housing. A migrated or missing fuse pin could lead to faster fatigue rates and possible failure of the adjacent fuse pins in the MLG Forward Trunnion Upper and Lower Housing. Failure of the fuse pins in the MLG Forward Trunnion Upper and Lower Housing could result in an incorrect MLG break-away sequence and cause the MLG to puncture the wing box which could result in fuel leaks. Failure of the fuse pins could also result in possible gear collapse causing a runway excursion during take-off or landing. Boeing has received four reports of retaining cross bolt hardware not fully engaged into the MLG Forward Trunnion Lower Housing fuse pins. Reports indicated the incorrectly installed cross bolt or bolts were found during a scheduled C-check inspection, a MLG replacement, a 4C inspection, and a hard landing inspection. All reports found the cross bolt and lock wire intact, but found the bolt not properly engaged in the fuse pin. The cross bolt and lock wire are used to prevent the fuse pin from migrating out of position. A migrated or missing fuse pin in the MLG Forward Trunnion Lower Housing can cause the remaining fuse pins in the MLG Forward Trunnion Upper and Lower Housing to fatigue at a faster rate. This service bulletin provides instructions to inspect and replace the necessary fuse pins in MLG Forward Trunnion Upper and Lower Housing. Correct installation of the cross bolt into the fuse pin will make sure all fuse pins in the MLG Forward Trunnion Upper and Lower Housing will not migrate. Boeing Service Related Problem (SRP) 777-SRP-57-0246 and Boeing Fleet Team Digest (FTD) 777 FTD 57-10006 are related to this service bulletin.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 5 of 37**ACTION** Do a Detailed Inspection (DET) of the MLG Forward Trunnion Lower Housing fuse pins for correctly installed cross bolts. If necessary, lift the airplane and replace the MLG Forward Trunnion Upper and Lower Housing fuse pins making sure cross bolts are correctly installed. **EFFECTIVITY** 777-200, -200LR, -300, -300ER and 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 available for airplanes in warranty as of October 28, 2010. Please refer to Paragraph 2.B., Industry Support Information. **MANPOWER Elapsed Hours**  **Total Task Hours Airplanes**  16.00 44.00 All
**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: August 24, 2011 777-57A0090 6 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 7 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 8 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT**

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### Commercial **Airplanes** 

# 777 Service Bulletin **ALERT Number: 777-57A0090**  Original Issue: August 24, 2011 ATA System: 5754 **SUBJECT:** WINGS - Landing Gear Attach Fittings and Support Beam - Main Landing Gear Forward Trunnion Lower Housing Fuse Pin - Inspection and Replacement 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 Refer to Service Bulletin Index D624W001 Part 3 for Airplane Variable Number, Line Number, and Serial Number data. This service bulletin is for the airplane(s) shown below.
**DESCRIPTION CONFIGURATION**  **GROUP** 777-200 Airplanes line number 1 thru 635

- 1 777-200 Airplanes with extended range (ER) option line number 41 thru 868 - 2
777-300 Airplanes line number 94 thru 567

- 3 777-200LR/-300ER and 777F Airplanes line number 423 thru 915

- 4

Airplane Models: 777-200, 777-200LR, 777-300, 777-300ER, 777F **Group Variable Number**  1 WA001 - WA017 1 WA076 - WA080

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 9 of 37**Group Variable Number**  1 WA086 - WA093 1 WA101 - WA104 1 WA116 - WA119 1 WA131 - WA137 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 2 WB001 - WB021 2 WB031 - WB046 2 WB051 - WB088 2 WB101 - WB106 2 WB121 - WB125 2 WB131 - WB148 2 WB151 - WB155 2 WB161 - WB177 2 WB181 - WB194 2 WB201 - WB215 2 WB231 - WB247 2 WB271 - WB273 2 WB276 - WB286 2 WB291 - WB302 2 WB306 - WB307 2 WB311 - WB337 2 WB341 - WB342 2 WB366 - WB368 2 WB371 - WB388 2 WB406

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 10 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT Group**  **Variable Number** 2 WB411 - WB413 2 WB416 - WB439 2 WB446 - WB453 2 WB476 2 WB481 - WB484 3 WB501 - WB512 3 WB531 - WB537 3 WB551 - WB554 3 WB591 - WB597 3 WB601 - WB606 3 WB611 - WB622 3 WB631 - WB638 3 WB646 - WB649 2 WC051 - WC073 2 WC101 - WC104 2 WC111 - WC120 2 WC221 - WC224 2 WC241 - WC243 2 WC281 - WC290 2 WC301 - WC308 2 WC361 - WC364 2 WC371 - WC374 2 WC381 - WC395 2 WC441 2 WC446 - WC449 2 WC456 - WC459 2 WC486 - WC493 2 WC506 - WC508 2 WC521 - WC522 2 WC531 - WC536 2 WC546 - WC548 2 WC556 2 WC566 - WC567

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 11 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT Group**  **Variable Number** 2 WC571 - WC574 2 WC581 4 WD001 - WD002 4 WD011 - WD018 4 WD031 - WD036 4 WD046 - WD055 4 WD066 - WD075 4 WD081 - WD088 4 WD091 4 WD096 4 WD101 - WD103 4 WD501 - WD513 4 WD521 - WD541 4 WD546 - WD554 4 WD561 - WD573 4 WD581 - WD599 4 WD606 - WD609 4 WD621 - WD632 4 WD651 - WD665 4 WD671 - WD676 4 WD691 - WD709 4 WD741 - WD752 4 WD761 - WD771 4 WD786 - WD788 4 WD796 - WD813 4 WD826 - WD837 4 WD846 - WD861 4 WD871 - WD883 4 WD911 - WD915 4 WD921 - WD922 4 WD936 - WD939 4 WD946 - WD951 4 WD966 - WD970

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 12 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT Group**  **Variable Number** 4 WD981 - WD982 4 WD986 - WD987 4 WD996 4 WE001 - WE004 4 WE011 - WE012 4 WE021 - WE024 4 WE031 4 WE051 - WE052 4 WE071 4 WE081 - WE082 4 WE126 - WE131 4 WF001 - WF004 4 WF016 - WF020 4 WF031 - WF032 4 WF046 - WF053 4 WF076 - WF077 4 WF081 - WF088 4 WF096 - WF099 4 WF106 - WF107 4 WF111 - WF112 4 WF121 2. Spares Affected None. **B. Concurrent Requirements** None.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 13 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT C. Reason**  Accomplishment of this service bulletin will make sure the Main Landing Gear (MLG) Forward Trunnion Lower Housing fuse pins and related cross bolts are correctly installed. An incorrectly installed fuse pin and cross bolt could result in migration of the fuse pin from the MLG Forward Trunnion Lower Housing. A migrated or missing fuse pin could lead to faster fatigue rates and possible failure of the adjacent fuse pins in the MLG Forward Trunnion Upper and Lower Housing. Failure of the fuse pins in the MLG Forward Trunnion Upper and Lower Housing could result in an incorrect MLG break-away sequence and cause the MLG to puncture the wing box which could result in fuel leaks. Failure of the fuse pins could also result in possible gear collapse causing a runway excursion during take-off or landing. Boeing has received four reports of retaining cross bolt hardware not fully engaged into the MLG Forward Trunnion Lower Housing fuse pins. Reports indicated the incorrectly installed cross bolt or bolts were found during a scheduled C-check inspection, a MLG replacement, a 4C inspection, and a hard landing inspection. All reports found the cross bolt and lock wire intact, but found the bolt not properly engaged in the fuse pin. The cross bolt and lock wire are used to prevent the fuse pin from migrating out of position. A migrated or missing fuse pin in the MLG Forward Trunnion Lower Housing can cause the remaining fuse pins in the MLG Forward Trunnion Upper and Lower Housing to fatigue at a faster rate. This service bulletin provides instructions to inspect and replace the necessary fuse pins in MLG Forward Trunnion Upper and Lower Housing. Correct installation of the cross bolt into the fuse pin will make sure all fuse pins in the MLG Forward Trunnion Upper and Lower Housing will not migrate. Boeing Service Related Problem (SRP) 777-SRP-57-0246 and 777 Fleet Team Digest (FTD) 777 FTD 57-10006 are related to this service bulletin. **D. Description** Do a Detailed Inspection (DET) of the MLG Forward Trunnion Lower Housing fuse pins for correctly installed cross bolts. If necessary, lift the airplane and replace the MLG Forward Trunnion Upper and Lower Housing fuse pins making sure cross bolts are correctly installed. The work in this service bulletin is done in the maintenance zone(s) given below. **Group 1-2:**
**Affected Maintenance Zones Zone**  **Model** 143, 144 777-200 **Group 3:**
**Affected Maintenance Zones Zone**  **Model** 143, 144 777-300

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 14 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT Group 4:** 
**Affected Maintenance Zones Zone**  **Model** 143, 144 777-200LR, 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. Accomplish the required actions, based on the applicable conditions, in Table 1, in accordance with Paragraph 3. Accomplishment Instructions. Evaluate the conditions and actions for the left and right Main Landing Gear (MLG) Forward Trunnion Upper and Lower Housing separately. **Table 1: Part 1 - Inspection of the MLG Forward Trunnion Lower Housing Fuse Pin Cross Bolts Repeat Interval**  **(Not to Exceed) Compliance Time**  **Action Condition** 

- Within 1125 daysafter the original issue date of this service bulletin. Do a Detailed Inspection (DET) of the left and right MLG Forward Trunnion Lower Housing fuse pin cross bolts to make surethe cross bolts are correctly installed and all MLG Forward Trunnion LowerHousing fuse pins are installed in accordance with Part 1. All Airplanes

- - No further action required (Terminating Action). Condition 1:1) All MLG Forward Trunnion Lower Housing cross bolts are correctly installed.-AND2) No MLG Forward Trunnion Lower Housing fuse pins are missing.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 15 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT Table 1: Part 1 - Inspection of the MLG Forward Trunnion Lower Housing Fuse Pin Cross Bolts**  **Repeat Interval (Not to Exceed)**  **Compliance Time Action**  **Condition**

- Before further flight. Replace all fuse pins in MLG Forward TrunnionUpper and Lower Housing in accordance withPart 2 (Terminating Action). Condition 2:1) Any MLG Forward Trunnion Lower Housing crossbolt is not correctly installed.-OR2) Any MLG Forward Trunnion Lower Housing fuse pin is missing. **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 and replacement 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. **Elapsed Hours Task Hours**  **Number of Persons Task**  1.00 1.00 1 Get Access 0.50 0.50 1 FIGURE 1: Inspect 0.50 0.50 1 FIGURE 2: Inspect 2.50 12.50 5 Lift the Airplane 1.00 2.00 2 Remove Load Straps 3.00 6.00 2 FIGURE 3: Replace

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 16 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT Elapsed Hours**  **Task Hours Number of Persons**  **Task** 3.00 6.00 2 FIGURE 4: Replace 1.00 2.00 2 Install Load Straps 2.50 12.50 5 Lower the Airplane 1.00 1.00 1 Close Access 16.00 44.00 TOTAL FOR EACH AIRPLANE **H. Weight and Balance Changes** None. **I. Electrical Load Data** Not changed. **J. References** 1. Existing Data a. Boeing Service Related Problem (SRP) 777-SRP-57-0246 b. Service Bulletin Index D624W001 c. 777 Aircraft Maintenance Manual (AMM) 07-11-01, 07-11-03, 32-00-15, 32-00-30, 32-11-01 d. 777 Fleet Team Digest (FTD) 57-10006 2. Data supplied with this Service Bulletin None. 3. Installation Drawings Used in the Preparation of this Service Bulletin
**Title Drawing Number**  SUPPORT INSTL - FORWARD TRUNNION MLG 112W1701 This drawing was used to prepare this service bulletin. This drawing is not necessary to make the specified changes, and is not supplied with this service bulletin. This drawing may not be applicable to all airplane configurations or operators. **K. Publications Affected** 1. Publications:

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 17 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT Chapter-Section**  **Publication** 32-11 777 Aircraft Maintenance Manual 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** Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 18 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT 2. MATERIAL INFORMATION**  **A. Material - Price and Availability** Boeing can supply the parts shown in Paragraph 2.C., Parts Necessary for Each Airplane. Operators are encouraged to share schedule requirements with Boeing for incorporation of the service bulletin. The parts are subject to the terms and conditions of the Boeing standard purchase order acknowledgment. Prices are in United States Dollars. Terms: Net 30 days. Reference this service bulletin and submit your purchase order by one of these methods: 1. Order on-line via ATA Spec 2000 or The Boeing PART Page 2. Fax to (206) 662-7145 **Group 1: REFER TO THE BOEING PART PAGE ON MYBOEINGFLEET.COM OR CONTACT FIRST RESPONDER**  **AT FR@BOEING.COM FOR THE LATEST REORDER LEAD TIME (ROLT) AND PRICE INFORMATION**
**Unit Price as of the original issue** **date of this Ser vice Bulletin (US**  **Dollars) ROLT as of the**  **original issue date of this Ser** **vice Bulletin (Cal endar Days)**  **Name Part Number** 

$ 1,213.00 300 LOWER FUSE PIN 112W1712-3 $ 1,378.00 300 UPPER FUSE PIN 112W1712-4 **Group 2: REFER TO THE BOEING PART PAGE ON MYBOEINGFLEET.COM OR CONTACT FIRST RESPONDER**  **AT FR@BOEING.COM FOR THE LATEST REORDER LEAD TIME (ROLT) AND PRICE INFORMATION**
**Unit Price as of the original issue** **date of this Ser vice Bulletin (US**  **Dollars) ROLT as of the**  **original issue date of this Ser** **vice Bulletin (Cal endar Days)**  **Name Part Number** 

$ 1,213.00 300 LOWER FUSE PIN 112W1712-3 $ 2,191.00 300 UPPER FUSE PIN 112W1712-5

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 19 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT Group 3:**  **REFER TO THE BOEING PART PAGE ON MYBOEINGFLEET.COM OR CONTACT FIRST RESPONDER AT FR@BOEING.COM FOR THE LATEST REORDER LEAD TIME (ROLT) AND PRICE INFORMATION** 
**Unit Price as of the original issue** **date of this Ser vice Bulletin (US**  **Dollars) ROLT as of the**  **original issue date of this Ser** **vice Bulletin (Cal endar Days)**  **Name Part Number** 

$ 2,191.00 300 UPPER FUSE PIN 112W1712-5 $ 5,482.00 300 LOWER FUSE PIN 112W1712-6 **Group 4: REFER TO THE BOEING PART PAGE ON MYBOEINGFLEET.COM OR CONTACT FIRST RESPONDER**  **AT FR@BOEING.COM FOR THE LATEST REORDER LEAD TIME (ROLT) AND PRICE INFORMATION**
**Unit Price as of the original issue** **date of this Ser vice Bulletin (US**  **Dollars) ROLT as of the**  **original issue date of this Ser** **vice Bulletin (Cal endar Days)**  **Name Part Number** 

$ 1,751.00 300 LOWER FUSE PIN 112W1712-7 $ 1,751.00 300 UPPER FUSE PIN 112W1712-8 **B. Industry Support Information** Boeing warranty remedies are available for 777 airplanes in warranty as of October 28, 2010. For inspection task hour reimbursement for airplanes in warranty as of that date, send a warranty claim to Boeing Commercial Airplanes Group - Warranties. If the condition described in this service bulletin is found during the inspection for airplanes in warranty as of that date and additional task hours and kits, parts, and/or special tools are required, send a warranty claim to Boeing Commercial Airplanes Group - Warranties. Please refer to this service bulletin number and reference the airplane variable numbers in your purchase order. **C. Parts Necessary For Each Airplane** 1. Kits/Parts None. 2. Parts and Materials Supplied by the Operator **Group 1:**
**Notes Name**  **QTY Part Number /**  **Specification** (a) LOWER FUSE PIN 8 112W1712-3 (a) UPPER FUSE PIN 4 112W1712-4

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 20 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT Group 1:** 
**Notes Name**  **QTY Part Number /**  **Specification** (a) The quantity shown is the total quantity required per airplane if all parts for both the left and right Main Landing Gear (MLG) Forward Trunnion Upper and Lower Housing require replacement. Parts are only required if replacement as shown in this service bulletin is necessary. **Group 2:**
**Notes Name**  **QTY Part Number /**  **Specification** (a) LOWER FUSE PIN 8 112W1712-3 (a) UPPER FUSE PIN 4 112W1712-5 (a) The quantity shown is the total quantity required per airplane if all parts for both the left and right MLG Forward Trunnion Upper and Lower Housing require replacement. Parts are only required if replacement as shown in this service bulletin is necessary. **Group 3:**
**Notes Name**  **QTY Part Number /**  **Specification** (a) UPPER FUSE PIN 4 112W1712-5 (a) LOWER FUSE PIN 8 112W1712-6 (a) The quantity shown is the total quantity required per airplane if all parts for both the left and right MLG Forward Trunnion Upper and Lower Housing require replacement. Parts are only required if replacement as shown in this service bulletin is necessary. **Group 4:**
**Notes Name**  **QTY Part Number /**  **Specification** (a) LOWER FUSE PIN 8 112W1712-7 (a) UPPER FUSE PIN 4 112W1712-8 (a) The quantity shown is the total quantity required per airplane if all parts for both the left and right MLG Forward Trunnion Upper and Lower Housing require replacement. Parts are only required if replacement as shown in this service bulletin is necessary.
3. Parts Modified and Reidentified None.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 21 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT**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: August 24, 2011 777-57A0090 22 of 37 **BOEING SERVICE BULLETIN 777-57A0090 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. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for definition of the acronyms. 2. Obey all of the warnings and cautions given in the specified manual sections. 3. Unless shown differently, these dimensions and tolerances are used: – Linear dimensions are in inches – Tolerance on linear dimensions, other than rivet and bolt edge margins, is plus or minus 0.03 inch – Tolerance on rivet and bolt edge margin is plus or minus 0.05 inch – Angular tolerance is plus or minus 2 degrees – Hole dimensions for standard solid rivets and fasteners are in Structural Repair Manual (SRM) Chapter 51 – Torque limits to tighten nuts and bolts are in SRM Chapter 51 4. Use the approved fastener and process material substitutions in accordance with SRM Chapter 51. 5. If the length of any fastener specified in this service bulletin does not meet installation standards given in SRM Chapter 51, then a fastener of the same specification, or an approved substitute, with a length which meets the installation standards given in SRM Chapter 51 may be used. In addition, washers may be installed for fastener grip length in accordance with SRM Chapter 51. 6. 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. 7. 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. 8. Boeing Service Letter 777-SL-51-013, Damage Reporting and Repair Plan/Design Guidelines, is an acceptable procedure to request information from Boeing for additional structural repair instructions. The Service Letter describes what information must be provided to Boeing before a structural repair can be provided.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 23 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT**9. The instructions in Paragraph 3.B., Work Instructions and the figures can include operation of tools or test equipment. Boeing Engineering Tool Drawings, the Illustrated Tool and Equipment Manual, and the Special Tool and Ground Handling Drawing Index contain data on versions of the tools or test equipment that you can use. It is permitted to use replaced tools. It is not permitted to use superseded tools. 10. If it is necessary to remove more parts for access, you can remove those parts. If you can get access without removing identified parts, it is not necessary to remove all of the identified parts. Jacking and shoring limitations must be observed. 11. Where the work instructions include installation of a kept part, a new or serviceable part with the same part number can be installed as an alternative to the kept part. **B. WORK INSTRUCTIONS** 1. Install Main Landing Gear (MLG) door locks. Refer to 777 AMM 32-00-15 as an accepted procedure. 2. Install MLG down locks. Refer to 777 AMM 32-00-30 as an accepted procedure. 3. Do Part 1: Inspection of the MLG Forward Trunnion Lower Housing Fuse Pin Cross Bolts. a. Condition 1: 1) All MLG Forward Trunnion Lower Housing cross bolts are correctly installed and 2) no MLG Forward Trunnion Lower Housing fuse pins are missing. (1) No further action is required. b. Condition 2: 1) Any MLG Forward Trunnion Lower Housing fuse pin cross bolt is not correctly installed or 2) any MLG Forward Trunnion Lower Housing fuse pin is missing. (1) Do Part 2: Replacement of the MLG Forward Trunnion Upper and Lower Housing Fuse Pins. 4. Remove MLG down locks. Refer to 777 AMM 32-00-30 as an accepted procedure. 5. Remove MLG door locks. Refer to 777 AMM 32-00-15 as an accepted procedure. 6. Put the airplane back to a serviceable condition. **Part 1: Inspection of the MLG Forward Trunnion Lower Housing Fuse Pin Cross Bolts** 1. Do a Detailed Inspection (DET) of the left and right MLG Forward Trunnion Lower Housing fuse pin cross bolts to make sure the cross bolts are correctly installed and all MLG Forward Trunnion Lower Housing fuse pins are installed in accordance with the figures below. Right MLG Left MLG FIGURE 2 FIGURE 1

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 24 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT Part 2: Replacement of the MLG Forward Trunnion Upper and Lower Housing Fuse Pins**  1. Lift the airplane at the main jack points until the wheels are just off the ground. Refer to 777 AMM 07-11-01 as an accepted procedure. 2. Remove two side load straps from the supports near the MLG Forward Trunnion Upper and Lower Housing. Refer to 777 AMM 32-11-01 as an accepted procedure. 3. Replace all fuse pins in MLG Forward Trunnion Upper and Lower Housing in accordance with the figures below. Use Axle Jacks under the forward and aft axle jacking points to relieve the load on the fuse pins and adjust as needed. The load is approximately 9000 to 10000 lbs. Refer to 777 AMM 07-11-03 as an accepted procedure.Right MLG Left MLG FIGURE 4 FIGURE 3 4. Install two side load straps to the supports near the MLG Forward Trunnion Upper and Lower Housing. Refer to 777 AMM 32-11-01 as an accepted procedure. 5. Lower the airplane. Refer to 777 AMM 07-11-01 as an accepted procedure. 6. Put the airplane back to a serviceable condition.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 25 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT FIGURE 1: LEFT MLG FORWARD TRUNNION LOWER HOUSING FUSE PIN CROSS BOLT INSPECTION**  **(SHEET 1 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 26 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT FIGURE 1: LEFT MLG FORWARD TRUNNION LOWER HOUSING FUSE PIN CROSS BOLT INSPECTION**  **(SHEET 2 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 27 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** in MLG Forward Trunnion LowerHousing. Do a Detailed Inspection (DET) of the cross bolt to make surethe cross bolt is correctly installed in the fuse pin. The cross bolt should be fully engaged in the fuse pin. 4
- CROSS BOLT Inspect 1

**FIGURE 1: LEFT MLG FORWARD TRUNNION LOWER HOUSING FUSE PIN CROSS BOLT INSPECTION (SHEET 3 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 28 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT FIGURE 2: RIGHT MLG FORWARD TRUNNION LOWER HOUSING FUSE PIN CROSS BOLT INSPECTION**  **(SHEET 1 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 29 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT FIGURE 2: RIGHT MLG FORWARD TRUNNION LOWER HOUSING FUSE PIN CROSS BOLT INSPECTION**  **(SHEET 2 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 30 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** in MLG Forward Trunnion LowerHousing. Do a Detailed Inspection (DET) of the cross bolt to make surethe cross bolt is correctly installed in the fuse pin. The cross bolt should be fully engaged in the fuse pin. 4
- CROSS BOLT Inspect 1

**FIGURE 2: RIGHT MLG FORWARD TRUNNION LOWER HOUSING FUSE PIN CROSS BOLT INSPECTION (SHEET 3 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 31 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT FIGURE 3: LEFT MLG FORWARD TRUNNION UPPER AND LOWER HOUSING FUSE PIN REPLACEMENT**  **(SHEET 1 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 32 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT NOTE:**  Fuse pin replacement is recommended to be done one fuse pin at a time.

**FIGURE 3: LEFT MLG FORWARD TRUNNION UPPER AND LOWER HOUSING FUSE PIN REPLACEMENT (SHEET 2 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 33 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** Refer to 777 AMM32-11-01 as an accepted procedure. 2
- CROSS BOLT (UP- PER) Remove / Keep 1

2
- UPPER FUSE PIN Remove Refer to 777 AMM32-11-01 as an accepted procedure. 4
- CROSS BOLT (LOW- ER) Remove / Keep 2

4
- LOWER FUSE PIN Remove Refer to 777 AMM32-11-01 as an accepted procedure. 4
- LOWER FUSE PIN Install (New) 3

(a) 4
- CROSS BOLT (LOW- ER) Install (Kept)
Refer to 777 AMM32-11-01 as an accepted procedure. 2
- UPPER FUSE PIN Install (New) 4

(a) 2
- CROSS BOLT (UP- PER) Install (Kept) (a) Make sure the cross bolt is fully engaged in the fuse pin.

**FIGURE 3: LEFT MLG FORWARD TRUNNION UPPER AND LOWER HOUSING FUSE PIN REPLACEMENT (SHEET 3 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 34 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT FIGURE 4: RIGHT MLG FORWARD TRUNNION UPPER AND LOWER HOUSING FUSE PIN REPLACEMENT**  **(SHEET 1 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 35 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT NOTE:**  Fuse pin replacement is recommended to be done one fuse pin at a time.

**FIGURE 4: RIGHT MLG FORWARD TRUNNION UPPER AND LOWER HOUSING FUSE PIN REPLACEMENT (SHEET 2 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 36 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** Refer to 777 AMM32-11-01 as an accepted procedure. 2
- CROSS BOLT (UP- PER) Remove / Keep 1

2
- UPPER FUSE PIN Remove Refer to 777 AMM32-11-01 as an accepted procedure. 4
- CROSS BOLT (LOW- ER) Remove / Keep 2

4
- LOWER FUSE PIN Remove Refer to 777 AMM32-11-01 as an accepted procedure. 4
- LOWER FUSE PIN Install (New) 3

(a) 4
- CROSS BOLT (LOW- ER) Install (Kept)
Refer to 777 AMM32-11-01 as an accepted procedure. 2
- UPPER FUSE PIN Install (New) 4

(a) 2
- CROSS BOLT (UP- PER) Install (Kept) (a) Make sure the cross bolt is fully engaged in the fuse pin.

**FIGURE 4: RIGHT MLG FORWARD TRUNNION UPPER AND LOWER HOUSING FUSE PIN REPLACEMENT (SHEET 3 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: August 24, 2011 777-57A0090 37 of 37 **BOEING SERVICE BULLETIN 777-57A0090 ALERT**  **ALERT**