### Commercial **Airplanes** 

# 777 Service Bulletin **ALERT Number: 777-53A0078**  Original Issue: December 05, 2014 ATA System: 5383 **SUBJECT:** FUSELAGE - Section 48 - Station 2150 - Aft Pressure Bulkhead Web Lap Splice Inspection Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15 CFR 300-774). 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 © 2014 Boeing. Unpublished Work. All Rights Reserved. Treatment of this document and its content is governed by contract with Boeing. Rights to use this document are licensed on a per aircraft basis and such rights may not be transferable. For more information, contact The Boeing Company. 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, KC-46, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8, Poseidon and Boeing liveries 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.

Original Issue: December 05, 2014 777-53A0078 1 of 30 4.0Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 2 of 30 **BOEING SERVICE BULLETIN 777-53A0078 ALERT**  **ALERT**

BLANK PAGE**Table of Contents** Summary...................................................... 5 1. PLANNING INFORMATION ........................................ 9 A. Effectivity................................................ 9 1. Airplanes............................................. 9 2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 B. Concurrent Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 C. Reason. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 D. Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 H. Weight and Balance Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 I. Electrical Load Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 J. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 1. Existing Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 2. Data Supplied with this Service Bulletin:. . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3. Installation Drawings Used in the Preparation of this Service Bulletin:. . . . . . . . . . . 19 K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 L. Interchangeability and Intermixability of Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . 20 M. Software Accomplishment Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 2. MATERIAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 A. Material - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 B. Industry Support Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 C. Parts Necessary for Each Airplane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 1. Kits/Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 2. Parts and Materials Supplied by the Operator. . . . . . . . . . . . . . . . . . . . . . . . 21 3. Parts Modified and Reidentified. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 4. Parts Removed and Not Replaced. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 D. Parts Necessary to Change Spares. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 F. Special Tooling Necessary to do this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . 21 3. ACCOMPLISHMENT INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 A. GENERAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 B. WORK INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 FIGURE 1: AFT PRESSURE BULKHEAD RADIAL WEB LAP SPLICES INSPECTIONS. . . . . . . . 26

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 3 of 30 **BOEING SERVICE BULLETIN 777-53A0078 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 4 of 30 **BOEING SERVICE BULLETIN 777-53A0078 ALERT**  **ALERT**

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### Commercial **Airplanes** 

# 777 Service Bulletin **ALERT Summary**  **Number: 777-53A0078** Original Issue: December 05, 2014 ATA System: 5383 **SUBJECT:** FUSELAGE - Section 48 - Station 2150 - Aft Pressure Bulkhead Web Lap Splice 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** This service bulletin gives instructions to provide a through the thickness examination of the aft web of the radial lap splices using Medium Frequency Eddy Current (MFEC) for fatigue cracks, and to install repairs if any crack is found. If these inspections and repairs are not done, fatigue cracks can develop in the bulkhead webs. If this Wide Spread Fatigue cracking is not found and repaired, the cracks can rapidly coalesce and can result in possible rapid decompression and loss of structural integrity Widespread Fatigue Damage (WFD) analysis of the 777, as required by 14 CFR 26.21(b), has resulted in the conclusion that existing MPD Section 9, Airworthiness Limitation Instruction (ALI) inspection program is not sufficient to preclude the occurrence of WFD in the aft webs of the aft pressure bulkhead lap splices as the airplane ages. The pressure bulkhead lap splices have multiple adjacent identical details which have the potential for Multi-Site Damage (MD) and the potential for WFD. 14 CFR 26.21 requires evaluation of such designs for the potential for WFD and implementation of the appropriate Service Actions to ensure that WFD is precluded before the Limit of Validity (LOV). The aft pressure bulkhead web lap splices affected by this service bulletin have been determined to be structure that is susceptible to WFD. Boeing has not received any reports of cracks in the pressure bulkhead lap splices. Fatigue cracking was found in the pressure bulkhead aft webs of the radial lap splices common to the full scale fatigue test article. Accomplishment of the inspections and repairs in this service bulletin will ensure that the aft web of the aft pressure bulkhead web lap splices are free of detectable cracks and maintain the structural integrity of the aft pressure bulkhead. Boeing Service Related Problem (SRP) 777-SRP-53-0463 is related to this service bulletin. This table is provided to operators for planning purposes only. Refer to the applicable sections for more information.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 5 of 30**Reference Affected**  **Planning Data** Paragraph 1.A.2., Spares Affected No Spares Affected Paragraph 1.E., Compliance and Paragraph 1.F., Approval Yes AD Related Paragraph 1.H., Weight and Balance Changes No Weight and Balance Change Paragraph 1.I., Electrical Load Data No Electrical Load Changed Paragraph 1.K., Publications Affected Yes Publications Affected Paragraph 1.K., Publications Affected No Airplane Flight Operations Affected (Flight CrewOperations Manual and/or FAA Approved Airplane Flight Manual) Paragraph 2.C.1., Kits/Parts No Kits/Parts Required Paragraph 2.C.2., Parts and Materials Supplied by the Operator No Operator Supplied Parts/Material Paragraph 2.F., Special Tooling Necessary to do this Service Bulletin No Special Tooling Required

**ACTION** Get access to the aft side of the aft pressure bulkhead. Do the Medium Frequency Eddy Current (MFEC) inspections around fasteners in the aft webs at the aft pressure bulkhead radial lap splices. If cracks are found, repair in accordance with the 777 Structural Repair Manual (SRM) or contact Boeing for repair instructions and do the repair. **EFFECTIVITY** All 777-200, 777-200LR, 777 -300, 777 -300ER and 777F Airplane(s), Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplane(s). **COMPLIANCE** Federal Aviation Administration (FAA) Airworthiness Directive AD 2012-07-06 is related to this service bulletin. The effective date of AD 2012-07-06 is May 15, 2012. Refer to Paragraph 1.E., Compliance. **INDUSTRY SUPPORT INFORMATION** Boeing warranty remedies are not available for the inspection(s) and/or repair procedures given in this service bulletin. **MANPOWER** Refer to Paragraph 1.G., Manpower.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 6 of 30 **BOEING SERVICE BULLETIN 777-53A0078 ALERT**  **ALERT MATERIAL INFORMATION**  None.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 7 of 30 **BOEING SERVICE BULLETIN 777-53A0078 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 8 of 30 **BOEING SERVICE BULLETIN 777-53A0078 ALERT**  **ALERT**

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### Commercial **Airplanes** 

# 777 Service Bulletin **ALERT Number: 777-53A0078**  Original Issue: December 05, 2014 ATA System: 5383 **SUBJECT:** FUSELAGE - Section 48 - Station 2150 - Aft Pressure Bulkhead Web Lap Splice 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 Refer to Service Bulletin Index D624W001 Part 3 for Airplane Variable Number, Line Number, and Serial Number data. This service bulletin is applicable to all 777-200, 777-200LR, 777-300, 777- 300ER and 777F airplanes in 1 Group. The Variable Numbers and Group Information for the applicable airplanes is given below. **NOTE:** The Variable Number table below includes all affected airplanes up to Line Number 1356. Affected airplanes after Line Number 1356 will be added to the service bulletin's MyBoeingFleet.com (MBF) "get effectivity" result when they are added to the MBF Fleet Profile Page.
**DESCRIPTION CONFIGURATION**  **GROUP** All 777 airplanes

- 1

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

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 9 of 30**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 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

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 10 of 30 **BOEING SERVICE BULLETIN 777-53A0078 ALERT**  **ALERT Group**  **Variable Number** 1 WB411 - WB413 1 WB416 - WB439 1 WB446 - WB453 1 WB476 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 - WC224 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

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 11 of 30 **BOEING SERVICE BULLETIN 777-53A0078 ALERT**  **ALERT Group**  **Variable Number** 1 WC571 - WC574 1 WC581 1 WC586 - WC587 1 WC591 - WC595 1 WD001 - WD002 1 WD011 - WD018 1 WD031 - WD036 1 WD046 - WD055 1 WD066 - WD075 1 WD081 - WD089 1 WD091 1 WD096 1 WD101 - WD106 1 WD111 - WD112 1 WD116 - WD117 1 WD121 - WD122 1 WD501 - WD513 1 WD521 - WD541 1 WD546 - WD554 1 WD561 - WD573 1 WD581 - WD599 1 WD606 - WD609 1 WD621 - WD632 1 WD651 - WD665 1 WD671 - WD677 1 WD691 - WD709 1 WD741 - WD752 1 WD761 - WD771 1 WD786 - WD788 1 WD796 - WD837 1 WD846 - WD867 1 WD871 - WD899 1 WD911 - WD918

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 12 of 30 **BOEING SERVICE BULLETIN 777-53A0078 ALERT**  **ALERT Group**  **Variable Number** 1 WD921 - WD933 1 WD936 - WD957 1 WD966 - WD970 1 WD981 - WD982 1 WD986 - WD987 1 WD991 - WD994 1 WD996 1 WE001 - WE007 1 WE011 - WE012 1 WE021 - WE026 1 WE031 - WE037 1 WE051 - WE057 1 WE071 - WE078 1 WE081 - WE084 1 WE091 - WE095 1 WE126 - WE148 1 WE151 - WE170 1 WE176 - WE178 1 WE186 - WE219 1 WE226 - WE231 1 WE236 - WE253 1 WE261 - WE267 1 WE271 - WE278 1 WE291 - WE297 1 WE301 - WE317 1 WE331 - WE343 1 WE351 - WE356 1 WE376 - WE377 1 WE381 1 WE386 - WE387 1 WE391 - WE392 1 WE396 - WE401 1 WE416 - WE420

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 13 of 30 **BOEING SERVICE BULLETIN 777-53A0078 ALERT**  **ALERT Group**  **Variable Number** 1 WE426 - WE428 1 WE436 - WE439 1 WE441 - WE445 1 WE451 - WE458 1 WE471 - WE474 1 WE486 - WE491 1 WE501 - WE504 1 WE511 - WE513 1 WE526 - WE528 1 WE536 - WE540 1 WE556 - WE563 1 WE566 - WE567 1 WE591 1 WE601 - WE605 1 WE626 1 WE631 1 WF001 - WF004 1 WF016 - WF027 1 WF031 - WF043 1 WF046 - WF067 1 WF075 - WF077 1 WF081 - WF088 1 WF096 - WF101 1 WF106 - WF109 1 WF111 - WF118 1 WF121 - WF124 1 WF131 - WF133 1 WF136 - WF140 1 WF146 - WF147 1 WF151 - WF152 1 WF156 - WF160 1 WF166 - WF173 1 WF176 - WF178

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 14 of 30 **BOEING SERVICE BULLETIN 777-53A0078 ALERT**  **ALERT Group**  **Variable Number** 1 WF181 - WF182 2. Spares Affected None. **B. Concurrent Requirements** None. **C. Reason** This service bulletin gives instructions to provide a through the thickness examination of the aft web of the radial lap splices using Medium Frequency Eddy Current (MFEC) for fatigue cracks, and to install repairs if any crack is found. If these inspections and repairs are not done, fatigue cracks can develop in the bulkhead webs. If this Wide Spread Fatigue cracking is not found and repaired, the cracks can rapidly coalesce and can result in possible rapid decompression and loss of structural integrity Widespread Fatigue Damage (WFD) analysis of the 777, as required by 14 CFR 26.21(b), has resulted in the conclusion that existing MPD Section 9, Airworthiness Limitation Instruction (ALI) inspection program is not sufficient to preclude the occurrence of WFD in the aft webs of the aft pressure bulkhead lap splices as the airplane ages. The pressure bulkhead lap splices have multiple adjacent identical details which have the potential for Multi-Site Damage (MSD) and the potential for WFD. 14 CFR 26.21 requires evaluation of such designs for the potential for WFD and implementation of the appropriate Service Actions to ensure that WFD is precluded before the Limit of Validity (LOV). The aft pressure bulkhead web lap splices affected by this service bulletin have been determined to be structure that is susceptible to WFD. Boeing has not received any reports of cracks in the pressure bulkhead lap splices. Fatigue cracking was found in the pressure bulkhead aft webs of the radial lap splices common to the full scale fatigue test article. Accomplishment of the inspections and repairs in this service bulletin will ensure that the aft web of the aft pressure bulkhead web lap splices are free of detectable cracks and maintain the structural integrity of the aft pressure bulkhead. Boeing Service Related Problem (SRP) 777-SRP-53-0463 is related to this service bulletin.

**D. Description** Get access to the aft side of the aft pressure bulkhead. Do the Medium Frequency Eddy Current (MFEC) inspections around fasteners in the aft webs at the aft pressure bulkhead radial lap splices. If cracks are found, repair in accordance with the 777 Structural Repair Manual (SRM) or contact Boeing for repair instructions and do the repair. The work in this service bulletin is done in the maintenance zone(s) given below.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 15 of 30 **BOEING SERVICE BULLETIN 777-53A0078 ALERT**  **ALERT Affected Maintenance Zones**  **Zone Model**  311, 312 777-200, 777-200LR, 777-300, 777-300ER, 777F **E. Compliance** Federal Aviation Administration (FAA) Airworthiness Directive AD 2012-07-06 is related to this service bulletin. The effective date of AD 2012-07-06 is May 15, 2012. Do the required actions in accordance with Paragraph 3. Accomplishment Instructions. When more than one OPTION is given for a CONDITION, do only one of the OPTION numbers. When more than one ACTION is given for a CONDITION number or an OPTION number, do all of the ACTION numbers for that CONDITION number or OPTION number. **Table 1 - Aft Pressure Bulkhead Web Lap Splice MFEC Inspections Repeat Interval**  **(Not to Exceed) Compliance Time (Whichever**  **Occurs Later ) Action**  **Condition**

- Within 4,000 flight cycle or 750 days afterthe original issue date of this service bulletin.whichever occurs first. Before 38,000total flight cycles.Do PART 1: AFT PRESSURE BULKHEAD RADIAL LAP SPLICE MEDIUM FREQUENCY EDDY CURRENT INSPECTION for any crack. (a) All airplanes

8,400 flight cycles Within 8,400 flight cycles of the previous inspection. Repeat PART 1: AFT PRESSURE BULKHEAD RADIAL LAP SPLICE MEDIUM FREQUENCYEDDY CURRENT INSPECTION for any crack. CONDITION 1: NO CRACK FOUND

(a)

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 16 of 30 **BOEING SERVICE BULLETIN 777-53A0078 ALERT**  **ALERT Table 1 - Aft Pressure Bulkhead Web Lap Splice MFEC Inspections**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later )**  **Action Condition** 

- Before further flight OPTION 1 (ACTION 1): Repair in accordance with the Structural Repair Manual (SRM). CONDITION 2: ANY CRACK FOUND

8,400 flight cycles Within 8,400 flight cycles of the previous inspection. OPTION 1 (ACTION 2): Repeat PART 1: AFT PRESSURE BULKHEAD RADIAL LAP SPLICE MEDIUM FREQUENCYEDDY CURRENT INSPECTION for any crack in unrepaired areas. (a)

- Before further flight OPTION 2 (ACTION 1): Contact Boeing for repair instructions and do the repair. 8,400 flight cycles Within 8,400 flight cycles of the previous inspection. OPTION 2 (ACTION 2): Repeat PART 1: AFT PRESSURE BULKHEAD RADIAL LAP SPLICE MEDIUM FREQUENCYEDDY CURRENT INSPECTION for any crack in unrepaired areas. (a) (a) It is not necessary to do inspections in accordance with this service bulletin in areas where existing repairs approved by the Boeing ODA via FAA form 8100-9 cover the affected aft web inspection areas. Continue to do inspections of these repairs in accordance with existing Damage Tolerance Inspection instructions, including those provided in the 777 Structural Repair Manual Section 53-80 and in Boeing Service Bulletin 777-53A0039.
**NOTE:** Once initiated, the Service Bulletin inspections will satisfy the High Frequency Eddy Current (HFEC) inspections of the aft webs currently required by Structural Significant Item in 777 MPD 53-80-I13A Section 9. The aft web detail identified as HFEC direction 1, from the aft side in the DTR check form. **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.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 17 of 30 **BOEING SERVICE BULLETIN 777-53A0078 ALERT**  **ALERT**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. The Manager of the FAA Seattle Aircraft Certification Office approves incorporation of the inspections per this service bulletin (SB) along with the corresponding compliance times specified in Paragraph 1.E. "Compliance" of SB 777-53A0078, Original Issue, as an Alternative Method of Compliance (AMOC) to the inspections defined in the Damage Tolerance Rating Check Form Document D622W001-DTR for the corresponding locations of Structural Significant Item 53-80-I13A and in Subsection B, Airworthiness Limitations-Structural Inspections of Section 9 of the Maintenance Planning Document D622W001-9, required by paragraphs (g) and (h) of AD 2012-07-06. When this SB specifies contacting Boeing for repair instructions, the repair instructions must be approved by the FAA in accordance with paragraph (j) of AD 2012-07-06. This AMOC only applies to the areas inspected in accordance with this SB. All provisions of AD 2012-07-06 that are not specifically referenced in this paragraph remain fully applicable and must be complied with accordingly. **G. Manpower** The table below shows an estimate of the task hours necessary to do this inspection for each aft pressure bulkhead. 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**  0.50 0.50 1 Open Access 3.75 7.50 2 Figure 1 0.50 0.50 1 Close Access 4.75 8.50 TOTAL FOR EACH AIRPLANE
**NOTE:** Additional time will be required for repair if any crack is found. **H. Weight and Balance Changes** None. **I. Electrical Load Data** Not changed.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 18 of 30 **BOEING SERVICE BULLETIN 777-53A0078 ALERT**  **ALERT J. References**  1. Existing Data: a. Boeing Service Bulletin 777-53A0039 b. Boeing Service Letter 777-SL-51-013 c. Boeing Service Related Problem (SRP) 777-SRP-53-0463 d. Federal Aviation Administration (FAA) Airworthiness Directive (AD) 2012-07-06 e. Service Bulletin Index D624W001 f. 777 Illustrated Tool and Equipment Manual (ITEM) 53-80-03 g. 777 Maintenance Planning Data (MPD), D622W001-9, Section 9, Subsection B, and D622W001-DTR h. 777 Non-Destructive Testing (NDT) Manual Part 6, 53-80-06 i. 777-200 Structural Repair Manual (SRM) 53-80-08 j. 777-300 Structural Repair Manual (SRM) 53-80-08 k. 777F Structural Repair Manual (SRM) 53-80-08 2. Data Supplied with this Service Bulletin: None. 3. Installation Drawings Used in the Preparation of this Service Bulletin: None. **K. Publications Affected** 1. Publications: **Chapter-Section**

**Publication** 53-80-08 Repair 2 777 Structural Repair 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. DTI requirements for the structure affected are contained in Paragraph 1.E., Compliance of this service bulletin.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 19 of 30 **BOEING SERVICE BULLETIN 777-53A0078 ALERT**  **ALERT L. Interchangeability and Intermixability of Parts**  Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts. **M. Software Accomplishment Summary** Not affected.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 20 of 30 **BOEING SERVICE BULLETIN 777-53A0078 ALERT**  **ALERT 2. MATERIAL INFORMATION**  **A. Material - Price and Availability** None. **B. Industry Support Information** Boeing warranty remedies are not available for the inspection(s) 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 None. 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.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 21 of 30 **BOEING SERVICE BULLETIN 777-53A0078 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 22 of 30 **BOEING SERVICE BULLETIN 777-53A0078 ALERT**  **ALERT**

BLANK PAGE**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 Values: — Values for structural fasteners are given in 777 Structural Repair Manual, Chapter 51. — Values for airframe maintenance tasks are included in Chapter 20 of 777 Aircraft Maintenance Manual (AMM). — Values for electrical maintenance tasks are included in Chapter 20 of Standard Wiring Practices Manual (SWPM). — Values for engine maintenance tasks are included in Chapter 70 of 777 Aircraft Maintenance Manual (AMM). — Non-standard torque values for maintenance tasks are included in the applicable installation step.
4. 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. 5. 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. 6. 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.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 23 of 30 **BOEING SERVICE BULLETIN 777-53A0078 ALERT**  **ALERT**7. 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. 8. Use of colors in Figures is based on guidance from the ATA e-Business Program (ATA) iSpec 2200. 9. The compliance times for the actions in Paragraph 3.B., WORK INSTRUCTIONS are in Paragraph 1.E., Compliance. 10. Some steps in the Work Instructions are identified as Required for Compliance (RC). If this service bulletin is mandated by an Airworthiness Directive (AD), then the steps identified as RC must be done to comply with the AD. Alternative procedures for steps not identified with RC can be used if the RC steps can still be done as specified, and the airplane can be put back in a serviceable condition. An Alternative Method of Compliance (AMOC) is not necessary for deviations to steps that are not identified as RC. **B. WORK INSTRUCTIONS** 1. Open Service Access Door 311BL for access to the aft side of the aft pressure bulkhead. **NOTE:** Boeing recommends that an appropriate maintenance platform be installed for safe access to the aft surface of the pressure bulkhead. Refer to Platform Assembly J53003-() in 777 ITEM 53-80-03 as an accepted platform. 2. RC - Do PART 1: AFT PRESSURE BULKHEAD RADIAL LAP SPLICE MEDIUM FREQUENCY EDDY CURRENT INSPECTION for any crack. 3. RC - CONDITION 1: NO CRACK FOUND a. Repeat PART 1: AFT PRESSURE BULKHEAD RADIAL LAP SPLICE MEDIUM FREQUENCY EDDY CURRENT INSPECTION for any crack. 4. RC - CONDITION 2: ANY CRACK FOUND a. OPTION 1: (1) OPTION 1 (ACTION 1): Repair in accordance with 777-200 SRM 53-80-08 Repair 2, 777-300 SRM 53-80-08 Repair 2, or 777F SRM 53-80-08 Repair 2. (2) OPTION 1 (ACTION 2): Repeat PART 1: AFT PRESSURE BULKHEAD RADIAL LAP SPLICE MEDIUM FREQUENCY EDDY CURRENT INSPECTION for any crack in unrepaired areas. b. OPTION 2: (1) OPTION 2 (ACTION 1): Contact Boeing for repair instructions if the repair exceeds the applicability of 777-200 SRM 53-80-08 Repair 2, 777-300 SRM 53-80-08 Repair 2, or 777F SRM 53-80-08 Repair 2, and do the repair in accordance with the instructions from Boeing.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 24 of 30 **BOEING SERVICE BULLETIN 777-53A0078 ALERT**  **ALERT**(2) OPTION 2 (ACTION 2): Repeat PART 1: AFT PRESSURE BULKHEAD RADIAL LAP SPLICE MEDIUM FREQUENCY EDDY CURRENT INSPECTION for any crack in unrepaired areas. 5. Put the airplane back into a serviceable condition. Do the inspection again at the time given in Paragraph 1.E., Compliance. **PART 1: AFT PRESSURE BULKHEAD RADIAL LAP SPLICE MEDIUM FREQUENCY EDDY CURRENT INSPECTION**  1. Do Medium Frequency Eddy Current (MFEC) inspections of the aft webs in the aft pressure bulkhead radial lap splices for any crack in accordance with Figure 1.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 25 of 30 **BOEING SERVICE BULLETIN 777-53A0078 ALERT**  **ALERT FIGURE 1: AFT PRESSURE BULKHEAD RADIAL WEB LAP SPLICES INSPECTIONS**  **(SHEET 1 OF 5)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 26 of 30 **BOEING SERVICE BULLETIN 777-53A0078 ALERT**  **ALERT FIGURE 1: AFT PRESSURE BULKHEAD RADIAL WEB LAP SPLICES INSPECTIONS**  **(SHEET 2 OF 5)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 27 of 30 **BOEING SERVICE BULLETIN 777-53A0078 ALERT**  **ALERT FIGURE 1: AFT PRESSURE BULKHEAD RADIAL WEB LAP SPLICES INSPECTIONS**  **(SHEET 3 OF 5)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 28 of 30 **BOEING SERVICE BULLETIN 777-53A0078 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.

**FIGURE 1: AFT PRESSURE BULKHEAD RADIAL WEB LAP SPLICES INSPECTIONS (SHEET 4 OF 5)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 29 of 30 **BOEING SERVICE BULLETIN 777-53A0078 ALERT**  **ALERT More Data**  **Qty Identification**  **Name Task**  **Step** (a) (b) (c) (d) 12

- RADIAL WEB LAP SPLICES Inspect 1 (a) It is not necessary to do the inspection at locations covered by tear straps, failsafe straps, doublers, aft cover pan or the Y-ring pressure chord/failsafe chord. (b) Do Medium Frequency Eddy Current (MFEC) for any crack in accordance with 777 NDT Manual Part 6, 53-80-06. (c) It is not necessary to do inspections in accordance with this service bulletin in area where existing repairs cover the affected aft web inspection areas. Continue to do inspections of these repairs in accordance with existing Damage Tolerance Inspection instructions, including those provided in the 777 Structural Repair Manual and in Boeing Service Bulletin 777-53A0039.(d) On airplanes line number 423 and on, two bays common to Radial Web Lap Splice RS-16R contain HiLocs, not rivets. Refer to View A-A.

**FIGURE 1: AFT PRESSURE BULKHEAD RADIAL WEB LAP SPLICES INSPECTIONS (SHEET 5 OF 5)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 05, 2014 777-53A0078 30 of 30 **BOEING SERVICE BULLETIN 777-53A0078 ALERT**  **ALERT**