# Boeing Alert Service Bulletin 777-53A0075: Revision 2 - Rights: © The Boeing Company. Filed by the FAA in regulations.gov docket FAA-2021-0828; AD 2022-06-07 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. - Document: [Boeing Alert Service Bulletin 777-53A0075](https://openairdocs.org/service-documents/boeing/777-53a0075.md) - Title as filed: SB-777-53A0075-02 -- BOEING - Pages: 156 - PDF: https://openairdocs.org/files/sha256/58/cc/58cc9cc0f991b71317c43a06a2f4ac5e156aa0a3f9ab2c77969d1f17b7d387b4 - Page: https://openairdocs.org/service-documents/boeing/777-53a0075/file/58cc9cc0f991 ## Text Some pages are OCR from a scan. OCR can misread letters and numbers. Each page's text from the PDF; open the PDF at a page with #page=N. ### Page 1 Commercial Airplanes 777 Service Bulletin ALERT Number: 777-53A0075 Original Issue: January 14, 2015 Revision 2: February 22, 2021 ATA System: 5380 SUBJECT: FUSELAGE - Section 48 - Station 2370 Pivot Bulkhead Forward Outer Chord - Inspection and Repair 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. 9E991ECCN: BOEING PROPRIETARY, CONFIDENTIAL AND/OR TRADE SECRET Copyright © 2015 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 Unpublished Work.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: January 14, 2015 777-53A0075Revision 2: February 22, 2021 1 of 156 5.0 ### Page 2 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 2 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT BLANK PAGE ### Page 3 Table of Contents Revision Transmittal Sheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 1. PLANNING INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 A. Effectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 1. Airplanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 B. Concurrent Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 C. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 E. Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 H. Weight and Balance Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 1. Existing Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 2. Data Supplied with this Service Bulletin: . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 3. Installation Drawings Used in the Preparation of this Service Bulletin: . . . . . . . . . . . 39 K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 M. Software Accomplishment Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 2. MATERIAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 A. Material - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 C. Parts Necessary for Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 1. Kits/Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 2. Parts and Materials Supplied by the Operator . . . . . . . . . . . . . . . . . . . . . . . . 44 3. Parts Modified and Reidentified . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 4. Parts Removed and Not Replaced . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 D. Parts Necessary to Change Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 E. Special Tooling - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 F. Special Tooling Necessary to do this Service Bulletin . . . . . . . . . . . . . . . . . . . . . . . 45 3. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 B. WORK INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 FIGURE 1: LEFT SIDE - STA 2370 SKIN PANEL REMOVAL [Group 1, Configuration 1-2, 4; Group 2, Configuration 1-2, 4] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 FIGURE 2: RIGHT SIDE - STA 2370 SKIN PANEL REMOVAL [Group 1, Configuration 1-2, 4; Group 2, Configuration 1-2, 4] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 FIGURE 3: LEFT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD AND LONGERON FITTING - DET AND HFEC INSPECTION [Group 1, Configuration 1-2, 4; Group 2, Configuration 1-2, 4] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 FIGURE 4: RIGHT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD AND LONGERON FITTING - DET AND HFEC INSPECTION [Group 1, Configuration 1-2, 4; Group 2, Configuration 1-2, 4] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 3 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 4 FIGURE 5: LEFT SIDE - STA 2370 SKIN PANEL INSTALLATION [Group 1, Configuration 1-2, 4; Group 2, Configuration 1-2, 4] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 FIGURE 6: RIGHT SIDE - STA 2370 SKIN PANEL INSTALLATION [Group 1, Configuration 1-2, 4; Group 2, Configuration 1-2, 4] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 FIGURE 7: THIS FIGURE IS DELETED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 FIGURE 8: THIS FIGURE IS DELETED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 FIGURE 9: THIS FIGURE IS DELETED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 FIGURE 10: THIS FIGURE IS DELETED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 FIGURE 11: LEFT SIDE - STA 2370 PIVOT BULKHEAD ASSEMBLY STRUCTURE - HFEC INSPECTION [Group 1, Configuration 1-2, 4; Group 2, Configuration 1-2, 4] . . . . . . . . . . . . . . . . 93 FIGURE 12: RIGHT SIDE - STA 2370 PIVOT BULKHEAD ASSEMBLY STRUCTURE - HFEC INSPECTION [Group 1, Configuration 1-2, 4; Group 2, Configuration 1-2, 4] . . . . . . . . . . . . . . . . 95 FIGURE 13: THIS FIGURE IS DELETED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 FIGURE 14: THIS FIGURE IS DELETED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 FIGURE 15: THIS FIGURE IS DELETED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 FIGURE 16: THIS FIGURE IS DELETED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 FIGURE 17: THIS FIGURE IS DELETED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 FIGURE 18: THIS FIGURE IS DELETED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 FIGURE 19: LEFT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD AND LONGERON FITTING - POST-REPAIR DET AND HFEC INSPECTION [Group 1-2, Configuration 3] . 103 FIGURE 20: RIGHT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD AND LONGERON FITTING - POST-REPAIR DET AND HFEC INSPECTION [Group 1-2, Configuration 3] . 107 FIGURE 21: LEFT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD POST-REPAIR INSPECTION - SKIN PANEL INSTALLATION [Group 1-2, Configuration 3] . . . . . . . . 111 FIGURE 22: RIGHT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD POST-REPAIR INSPECTION - SKIN PANEL INSTALLATION [Group 1-2, Configuration 3] . . . . . . . . 116 FIGURE 23: THIS FIGURE IS DELETED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 FIGURE 24: THIS FIGURE IS DELETED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 FIGURE 25: LEFT SIDE - STA 2370 SKIN PANEL REMOVAL [Group 1-2, Configuration 3] . . . . . . 123 FIGURE 26: RIGHT SIDE - STA 2370 SKIN PANEL REMOVAL [Group 1-2, Configuration 3] . . . . . 127 FIGURE 27: LEFT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD POST REPAIR - FASTENER REMOVAL [Group 1, Configuration 3-4; Group 2, Configuration 3-4] . . . . 131 FIGURE 28: RIGHT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD POST REPAIR - FASTENER REMOVAL [Group 1, Configuration 3-4; Group 2, Configuration 3-4] . . . . 133 FIGURE 29: LEFT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD POST REPAIR - FASTENER INSTALLATION [Group 1, Configuration 3-4] . . . . . . . . . . . . . . . . . 135 FIGURE 30: RIGHT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD POST REPAIR - FASTENER INSTALLATION [Group 1, Configuration 3-4] . . . . . . . . . . . . . . . . . 137 FIGURE 31: LEFT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD POST REPAIR - FASTENER INSTALLATION [Group 2, Configuration 3-4] . . . . . . . . . . . . . . . . . 139 FIGURE 32: RIGHT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD POST REPAIR - FASTENER INSTALLATION [Group 2, Configuration 3-4] . . . . . . . . . . . . . . . . . 141 APPENDIX A: LOGIC DIAGRAM FOR PARAGRAPH 1.E., COMPLIANCE: TABLE 1: LEFT AND RIGHT SIDE, DET AND HFEC INSPECTION OF THE STATION 2370 PIVOT BULKHEAD FORWARD OUTER CHORD [Group 1-2, Configuration 1] . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 APPENDIX B: LOGIC DIAGRAM FOR PARAGRAPH 1.E., COMPLIANCE: TABLE 2: LEFT AND RIGHT SIDE, DET AND HFEC INSPECTION OF THE STATION 2370 PIVOT BULKHEAD FORWARD OUTER CHORD [Group 1-2, Configuration 2] . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 4 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 5 APPENDIX C: LOGIC DIAGRAM FOR PARAGRAPH 1.E., COMPLIANCE: TABLE 3: LEFT AND RIGHT SIDE, POST-REPAIR DET AND HFEC INSPECTION OF THE STATION 2370 PIVOT BULKHEAD FORWARD OUTER CHORD FOR SMALL CRACK REPAIR [Group 1-2, Configuration 3] . 149 APPENDIX D: LOGIC DIAGRAM FOR PARAGRAPH 1.E., COMPLIANCE: TABLE 4: LEFT AND RIGHT SIDE, POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD [Group 1-2, Configuration 4] . . . . . . . . . . . . . . . . . 153 APPENDIX E: BOEING PART DEMAND INTENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 5 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 6 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 6 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT BLANK PAGE ### Page 7 Commercial Airplanes 777 Service Bulletin ALERT Revision Transmittal SheetNumber: 777-53A0075Original Issue: January 14, 2015 Revision 2: February 22, 2021 ATA System: 5380 SUBJECT: FUSELAGE - Section 48 - Station 2370 Pivot Bulkhead Forward Outer Chord - Inspection and Repair This revision includes all pages of the service bulletin. COMPLIANCE INFORMATION RELATED TO THIS REVISION Federal Aviation Administration (FAA) Airworthiness Directive AD 2016-09-01 is related to this service bulletin. The Federal Aviation Administration (FAA) will possibly release an additional Airworthiness Directive related to this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin mandatory. Effects of this Revision on airplanes on which Original Issue or Revision 1 was previously done: ActionConditionGroup Do PART 1: STATION 2370 PIVOT BULKHEAD FORWARD OUTER CHORD AND LONGERON FITTING - DET AND HFEC INSPECTION, for any crack at the times specified in Compliance. Airplanes that have done Boeing Service Bulletin 777-53A0075 Origi- nal Issue or Revision 1 and have no crack found and no small crack re- pair done in accordance with Boeing Service Bulletin 777-53A0075 or modification installed in accordance with Boeing Service Bulletin 777-53- 0076 on the left or right side. Group 1 and 2, Configuration 2 Do the post-repair DET and HFEC inspection in accordance with PART 3, for any crack at the times speci- fied in Compliance. As an option, do the modification in accordance with Boeing Service Bulletin 777-53-0076 Revision 2. Airplanes that have done Boeing Service Bulletin 777-53A0075 Origi- nal Issue or Revision 1 PART 2 sta- tion 2370 pivot bulkhead forward chord - small crack repair on the left or right side, and have not done the modification in accordance with Boeing Service Bulletin 777-53-0076 on the left or right side. Group 1 and 2, Configuration 3 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 7 of 156 ### Page 8 ActionConditionGroup Do PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULK- HEAD ASSEMBLY STRUCTURE, for any crack at the times specified in Compliance. Airplanes that have done Boeing Service Bulletin 777-53A0075 and have done the modification in accor- dance with Boeing Service Bulletin 777-53-0076. Group 1 and 2, Configuration 4 REASON FOR REVISION This revision is sent to add a reference to Federal Aviation Administration (FAA) Airworthiness Directive AD 2016-09-01, add new post repair or modification inspection requirement, add new inspection locations on the longeron fitting and to remove the option to do a small crack repair because operators have experienced early crack findings prior to the inspection threshold. These sections were changed: 1. In Summary, Background, updated statement, added additional service history table, added Boeing Fleet Team Digest (FTD) and added Boeing Service Related Problem (SRP) reference. 2. In Summary, Action, updated statement. 3. In Summary, Compliance, added a reference to FAA Airworthiness Directive AD 2016-09-01, information for a possible release of an additional FAA AD, and updated conditions. 4. In Summary, Manpower, removed table. 5. In Summary, Material Information, updated appendix reference. 6. In Summary, updated the summary Illustration. 7. Paragraph 1.A.1., Airplanes, updated statement and added new configurations. 8. Paragraph 1.C., Reason, updated statement, added additional service history table, added Boeing FTD, added Boeing SRP reference and added the reason for revision statement. 9. Paragraph 1.D., Description, added new inspection requirements and update the effects of this revision on airplanes on which Original Issue or Revision 1 was previously done statement. 10. Paragraph 1.E., Compliance, added a reference to FAA Airworthiness Directive AD 2016-09-01, information for a possible release of an additional FAA AD, add appendix reference, updated existing compliance tables, added new compliance tables for new inspection requirements, and updated conditions. 11. Paragraph 1.F., Approval, updated statement and added Alternative Method of Compliance (AMOC) statement. 12. Paragraph 1.G., Manpower, updated existing, and added new manpower tables and notes. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 8 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 9 13. Paragraph 1.H. Weight and Balance Changes: added new statement. 14. In Paragraph 1.J.1., Existing Data, added reference to PRR, new Boeing SRP, new Boeing FTD and added FAA Airworthiness Directive AD 2016-09-01. 15. In Paragraph 1.K.1., Publications, changed table. 16. In Paragraph 2, Material Information, updated tables. 17. In Paragraph 2.B., Industry Support Information, updated statement. 18. In Paragraph 2.C.1., Kits/Parts, added new Replacement Kits and new Supplemental Kits. 19. In Paragraph 2.C.2., Parts and Materials Supplied by the Operator, added footnote. 20. In Paragraph 3.A., General Information, updated detailed inspection note and added appendix reference. 21. In Paragraph 3.B., Work Instructions, revised RC steps, updated existing work instructions and added new work instructions for new inspection requirements. 22. FIGURE 1, 2, 3, 4, 5, 6, 11, 12, 21, 22, 25 and 26, added group applicability. 23. FIGURE 3 and 4, updated title, added new inspection location and updated step tables. 24. FIGURE 7, 8, 9, 10, 13, 14, 15, 16, 17, 18, 23 and 24, information has been deleted within the figure. 25. FIGURE 11 and 12, updated figures and step tables. 26. FIGURE 19 and 20, updated title, added group applicability and new inspection location. 27. Added new Figure 27 thru Figure 32. 28. APPENDIX A, B, C and D, updated existing and added new logic diagrams. Vertical lines are put on the left edge of each page, except in Paragraph 1.A., Effectivity and format changes, to show the location of all content changes. Pages with no vertical lines have no changes. REVISION HISTORY January 14, 2015Original Issue: December 14, 2015Revision 1: February 22, 2021Revision 2: Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 9 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 10 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 10 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT BLANK PAGE ### Page 11 Commercial Airplanes 777 Service Bulletin ALERT SummaryNumber: 777-53A0075Original Issue: January 14, 2015 Revision 2: February 22, 2021 ATA System: 5380 SUBJECT: FUSELAGE - Section 48 - Station 2370 Pivot Bulkhead Forward Outer Chord - Inspection and Repair THIS DOCUMENT 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 DOCUMENT TO THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS DOCUMENT TO THE NEW OWNER. CONCURRENT REQUIREMENTS None. BACKGROUND This service bulletin is sent to give instructions for inspections of the left and right side forward outer chords of the Body Station (STA) 2370 pivot bulkhead and longeron fitting for cracks. Cracks in the STA 2370 pivot bulkhead forward outer chords that are not found and repaired can become large and result in a severed forward outer chord. Since the horizontal stabilizer is attached to the STA 2370 bulkhead at two pivot locations, this damage could cause the loss of horizontal stabilizer control, resulting in loss of controllability of the airplane. Two operators have reported finding cracks in the outer flanges of the left and right side forward outer chords of the STA 2370 pivot bulkhead on a total of eleven airplanes which prompted a safety investigation and the release of Boeing Service Bulletin (SB) 777-53A0075. Upon inspection in accordance with SB 777-53A0075 Revision 1, an operator reported large crack findings on eleven of fourteen airplanes below the 16,000 total flight cycle threshold. This led Boeing to reopen the safety investigation and MOM-MOM-19-0583 was sent to operators to gather additional information on the early crack finding. Based upon the data gathered, a total of 32 airplanes had crack findings below the Boeing SB 777-53A0075 Revision 1 inspection threshold. The cracks were fatigue cracks caused by a combination of a stress concentration and high stress due to complex loading in the structure at the transition radius of the forward outer chord flange. Accomplishment of the inspections in this service bulletin will help ensure that STA 2370 pivot bulkhead forward outer chord cracks are found and repaired before they can become large and result in damage that could result in the loss of horizontal stabilizer control. Boeing SB 777-53-0076 gives instructions to do a modification of the STA 2370 pivot bulkhead forward outer chord. The table below shows the crack findings and related service data that have been reported to Boeing prior to Boeing SB 777-53A0075 Revision 1. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 11 of 156 ### Page 12 Service History Crack Length (Inches)Crack LocationFlight HoursFlight CyclesModel 1.4 and 3.3Left Side39,14231,384777-200 2.93Right Side 2.3Left Side39,79731,504777-200 2.2Right Side 2.5Left Side38,75832,181777-200 2.3Right Side 2.5Left Side37,18229,383777-200 2.5Right Side 2.2Left Side34,29124,653777-300 2.2Right Side 2.25Left Side40,07435,011777-200 2.2Right Side 2.5Left Side33,56824,251777-300 2.03Right Side 2.35Left Side38,45530,462777-200 2.2Right Side 2.2Left Side39,16630,826777-200 2.4Right Side 2.5Left Side40,58833,809777-200 2.4Right Side 1.2Left Side63,94017,530777-300 1.65Right Side The table below shows the early crack findings prior to the inspection threshold of 16,000 total flight cycles accomplished in accordance with Boeing SB 777-53A0075 Original Issue or Revision 1, and related service data that have been reported to Boeing. Service History Crack Length (Inches)Crack LocationFlight HoursFlight CyclesModel 1.5Left Side93,27313,717777-200 -Right Side 2Left Side90,31713,671777-200 -Right Side Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 12 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 13 Service History Crack Length (Inches)Crack LocationFlight HoursFlight CyclesModel 2.3Left Side90,03514,840777-200 2.0Right Side 2.25Left Side100,55414,996777-200 -Right Side 1.78Left Side104,08315,531777-200 2.56Right Side -Left Side87,11813,399777-200 1.44Right Side -Left Side91,62313,620777-200 1.5Right Side 1.8Left Side90,59814,645777-200 2.2Right Side -Left Side94,03313,779777-200 1.5Right Side 1.4Left Side93,67013,946777-200 -Right Side 1.25Left Side92,52213,620777-200 -Right Side 0.5Left Side94,45414,021777-200 -Right Side 1.75Left Side103,61115,532777-200 1.4Right Side Boeing Fleet Team Digest (FTD) 777 FTD 53-13001 and 777 FTD 53-20001 are related to this service bulletin. Boeing Service Related Problem (SRP) 777-SRP-53-0455 and 777-SRP-53-0620 are related to this service bulletin. As a part of a service bulletin validation program, this inspection was completed on airplane WA174 by Service Bulletin 777-53A0075 Original Issue before the release of Revision 1 of this service bulletin. The inspection completed on airplane WA174 by Service Bulletin 777-53A0075 Original Issue is equivalent to the release of Revision 1 of this service bulletin. Airplane WA174 has the configuration of a Group 2 airplane. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 13 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 14 This table is provided to operators for planning purposes only. Refer to the applicable sections for more information. ReferenceAffectedPlanning Data Paragraph 1.A.2., Spares AffectedNoSpares Affected Paragraph 1.E., Compliance and Paragraph 1.F., Approval YesAD Related Paragraph 1.H., Weight and Balance ChangesYes (a)Weight and Balance Change Paragraph 1.I., Electrical Load DataNoElectrical Load Changed Paragraph 1.K., Publications AffectedYesPublications Affected Paragraph 1.K., Publications AffectedNoAirplane Flight Operations Affected (Flight Crew Operations Manual and/or FAA Approved Air- plane Flight Manual) Paragraph 2.C.1., Kits/PartsYesKits/Parts Required Paragraph 2.C.2., Parts and Materials Supplied by the Operator YesOperator Supplied Parts/Material Paragraph 2.F., Special Tooling Necessary to do this Service Bulletin NoSpecial Tooling Required (a) Only if the repair was done. ACTION (PRR 62685-R, PRR 62777-97S) On the left and right side, do a DET and HFEC inspection of the Station (STA) 2370 pivot bulkhead forward outer chord, longeron fitting or bulkhead assembly structure for any crack and do applicable on-condition actions. EFFECTIVITY 777-200/-300 Airplanes. Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplanes. COMPLIANCE Federal Aviation Administration (FAA) Airworthiness Directive AD 2016-09-01 is related to this service bulletin. The effective date of AD 2016-09-01 is June 6, 2016. The Federal Aviation Administration (FAA) will possibly release an additional 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 November 20, 2013. Please refer to Paragraph 2.B., Industry Support Information. The warranty remedies will expire eight years from the original issue date of this service bulletin. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 14 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 15 MANPOWER Refer to Paragraph 1.G., Manpower. MATERIAL INFORMATION Boeing Supplied Kits/Parts. Operator Supplied Parts/Materials. Refer to Paragraph 2.A., Material - Price and Availability. Operators are encouraged to complete the survey provided in APPENDIX E of this service bulletin to help Boeing predict the quantity and timing of the Boeing Supplied Kits/Parts. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 15 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 16 (OCR) BOEING SERVICE BULLETIN 777-53A0075 ALERT ALERT ON THE LEFT AND RIGHT SIDE, DO A DET AND HFEC INSPECTION OF THE STATION (STA) 2370 PIVOT BULKHEAD FORWARD OUTER CHORD LONGERON FITTING OR BULKHEAD ASSEMBLY STRUCTURE FOR ANY CRACK AND DO APPLICABLE ON-CONDITION ACTIONS. 2357294 Original Issue: January 14, 2015 Revision 2: February 22, 2021 PROPRIETARY - Copyright © Unpublished Export Controlled ECCN: 9E991 - BOEING 777-53A0075 Work - See page 1 for details. 16 of 156 ### Page 17 Commercial Airplanes 777 Service Bulletin ALERT Number: 777-53A0075 Original Issue: January 14, 2015 Revision 2: February 22, 2021 ATA System: 5380 SUBJECT: FUSELAGE - Section 48 - Station 2370 Pivot Bulkhead Forward Outer Chord - Inspection and Repair THIS DOCUMENT 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 DOCUMENT TO THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS DOCUMENT TO THE NEW OWNER. 1. PLANNING INFORMATION A. Effectivity 1. Airplanes This bulletin is applicable to 777-200, 777-300 Airplane(s), line number(s) 1-244 in 2 Group(s). Where the effectivity is presented with hyphens between line numbers, the airplane applicability means "through" and "inclusive", e.g. line numbers 1-9 means line numbers 1 through 9 inclusive. Refer to Service Bulletin Index D624W001 Part 3 for Airplane Variable Number, Line Number, and Serial Number data. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 17 of 156 ### Page 18 DESCRIPTIONCONFIGURATIONGROUP 777 Airplanes, line numbers 1 through 40.- 1 777 Airplanes that have not done Boeing Service Bulletin 777-53A0075 Original Issue or Revision 1. 1 777 Airplanes that have done Boeing Service Bulletin 777-53A0075 Original Issue or Revision 1 and have no crack found and no small crack repair done in accordance with Boeing Service Bulletin 777-53A0075 or modification installed in accordance with Boeing Service Bulletin 777-53-0076 on the left or right side. 2 777 Airplanes that have done Boeing Service Bulletin 777-53A0075 Original Issue or Revision 1 PART 2 Station 2370 pivot bulkhead forward chord - small crack repair on the left or right side, and have not done the modification in accordance with Boeing Service Bulletin 777-53-0076 on the left or right side. 3 777 Airplanes that have done Boeing Service Bulletin 777-53A0075 and have done the modification in accordance with Boeing Service Bulletin 777-53-0076 on the left or right side. 4 777 Airplanes, line numbers 41 through 244.- 2 777 Airplanes that have not done Boeing Service Bulletin 777-53A0075 Original Issue or Revision 1. 1 777 Airplanes that have done Boeing Service Bulletin 777-53A0075 Original Issue or Revision 1 and have no crack found and no small crack repair done in accordance with Boeing Service Bulletin 777-53A0075 or modification installed in accordance with Boeing Service Bulletin 777-53-0076 on the left or right side. 2 777 Airplanes that have done Boeing Service Bulletin 777-53A0075 Original Issue or Revision 1 PART 2 Station 2370 pivot bulkhead forward chord - small crack repair on the left or right side, and have not done the modification in accordance with Boeing Service Bulletin 777-53-0076 on the left or right side. 3 777 Airplanes that have done Boeing Service Bulletin 777-53A0075 and have done the modification in accordance with Boeing Service Bulletin 777-53-0076 on the left or right side. 4 Airplane Models: 777-200, 777-300 GroupVariable Number 1WA001 - WA017 GroupVariable Number 1WA076 - WA080 GroupVariable Number 1WA086 - WA087 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 18 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 19 GroupVariable Number 2WA088 - WA093 1WA101 - WA104 1WA116 - WA117 2WA118 - WA119 1WA131 - WA135 2WA136 - WA137 1WA171 - WA173 2WA174 - WA175 1WA196 - WA197 2WA198 2WA206 - WA212 2WA221 - WA223 2WA231 - WA232 2WA241 - WA245 GroupVariable Number 2WB001 - WB020 2WB031 2WB051 - WB072 2WB101 - WB106 2WB121 - WB125 2WB131 - WB133 2WB151 - WB153 2WB161 - WB171 2WB181 - WB188 2WB231 - WB235 2WB271 - WB272 2WB276 - WB286 2WB291 - WB297 2WB306 - WB307 GroupVariable Number 2WB311 - WB318 2WB336 - WB337 2WB366 2WB371 - WB383 2WB406 2WB411 - WB413 2WB416 - WB426 2WB446 - WB448 2WB501 - WB506 2WB531 - WB535 2WB551 - WB553 2WB591 - WB595 2WB601 - WB602 2WB611 - WB615 2. Spares Affected None. B. Concurrent Requirements None. C. Reason This service bulletin is sent to give instructions for inspections of the left and right side forward outer chords of the Body Station (STA) 2370 pivot bulkhead and longeron fitting for cracks. Cracks in the STA 2370 pivot bulkhead forward outer chords that are not found and repaired can become large and result in a severed forward outer chord. Since the horizontal stabilizer is attached to the STA 2370 bulkhead at two pivot locations, this damage could cause the loss of horizontal stabilizer control, resulting in loss of controllability of the airplane. Two operators have reported finding cracks in the outer flanges of the left and right side forward outer chords of the STA 2370 pivot bulkhead on a total of eleven airplanes which prompted a safety investigation and the release of Boeing Service Bulletin (SB) 777-53A0075. Upon inspection in accordance with SB 777-53A0075 Revision 1, an operator reported large crack findings on eleven of fourteen airplanes below the 16,000 total flight cycle threshold. This led Boeing to reopen the safety investigation and MOM-MOM-19-0583 was sent to operators to gather additional information on the early crack finding. Based upon the data gathered, a total of 32 airplanes had crack findings below the Boeing SB 777-53A0075 Revision 1 inspection threshold. The cracks were fatigue cracks caused by a combination of a stress concentration and high stress due to complex loading in the structure at the transition radius of the forward outer chord flange. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 19 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 20 Accomplishment of the inspections in this service bulletin will help ensure that STA 2370 pivot bulkhead forward outer chord cracks are found and repaired before they can become large and result in damage that could result in the loss of horizontal stabilizer control. Boeing SB 777-53-0076 gives instructions to do a modification of the STA 2370 pivot bulkhead forward outer chord. The table below shows the crack findings and related service data that have been reported to Boeing prior to Boeing SB 777-53A0075 Revision 1. Service History Crack Length (Inches)Crack LocationFlight HoursFlight CyclesModel 1.4 and 3.3Left Side39,14231,384777-200 2.93Right Side 2.3Left Side39,79731,504777-200 2.2Right Side 2.5Left Side38,75832,181777-200 2.3Right Side 2.5Left Side37,18229,383777-200 2.5Right Side 2.2Left Side34,29124,653777-300 2.2Right Side 2.25Left Side40,07435,011777-200 2.2Right Side 2.5Left Side33,56824,251777-300 2.03Right Side 2.35Left Side38,45530,462777-200 2.2Right Side 2.2Left Side39,16630,826777-200 2.4Right Side 2.5Left Side40,58833,809777-200 2.4Right Side 1.2Left Side63,94017,530777-300 1.65Right Side The table below shows the early crack findings prior to the inspection threshold of 16,000 total flight cycles accomplished in accordance with Boeing SB 777-53A0075 Original Issue or Revision 1, and related service data that have been reported to Boeing. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 20 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 21 Service History Crack Length (Inches)Crack LocationFlight HoursFlight CyclesModel 1.5Left Side93,27313,717777-200 -Right Side 2Left Side90,31713,671777-200 -Right Side 2.3Left Side90,03514,840777-200 2.0Right Side 2.25Left Side100,55414,996777-200 -Right Side 1.78Left Side104,08315,531777-200 2.56Right Side -Left Side87,11813,399777-200 1.44Right Side -Left Side91,62313,620777-200 1.5Right Side 1.8Left Side90,59814,645777-200 2.2Right Side -Left Side94,03313,779777-200 1.5Right Side 1.4Left Side93,67013,946777-200 -Right Side 1.25Left Side92,52213,620777-200 -Right Side 0.5Left Side94,45414,021777-200 -Right Side 1.75Left Side103,61115,532777-200 1.4Right Side Boeing Fleet Team Digest (FTD) 777 FTD 53-13001 and 777 FTD 53-20001 are related to this service bulletin. Boeing Service Related Problem (SRP) 777-SRP-53-0455 and 777-SRP-53-0620 are related to this service bulletin. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 21 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 22 As a part of a service bulletin validation program, this inspection was completed on airplane WA174 by Service Bulletin 777-53A0075 Original Issue before the release of Revision 1 of this service bulletin. The inspection completed on airplane WA174 by Service Bulletin 777-53A0075 Original Issue is equivalent to the release of Revision 1 of this service bulletin. Airplane WA174 has the configuration of a Group 2 airplane. Revision 1 is sent to make changes identified during the validation of the Original Issue of this service bulletin and to clarify or correct issues identified by operators since the Original Issue. Revision 2 is sent to add a reference to Federal Aviation Administration (FAA) Airworthiness Directive AD 2016-09-01, add new post repair or modification inspection requirement, add new inspection locations on the longeron fitting and to remove the option to do a small crack repair because operators have experienced early crack findings prior to the inspection threshold. D. Description On the left and right side, do a DET and HFEC inspection of the Station (STA) 2370 pivot bulkhead forward outer chord, longeron fitting or bulkhead assembly structure for any crack and do applicable on-condition actions. Effects of this Revision on airplanes on which Original Issue or Revision 1 was previously done: ActionConditionGroup Do PART 1: STATION 2370 PIVOT BULKHEAD FORWARD OUTER CHORD AND LONGERON FITTING - DET AND HFEC INSPECTION, for any crack at the times specified in Compliance. Airplanes that have done Boeing Service Bulletin 777-53A0075 Origi- nal Issue or Revision 1 and have no crack found and no small crack re- pair done in accordance with Boeing Service Bulletin 777-53A0075 or modification installed in accordance with Boeing Service Bulletin 777-53- 0076 on the left or right side. Group 1 and 2, Configuration 2 Do the post-repair DET and HFEC inspection in accordance with PART 3, for any crack at the times speci- fied in Compliance. As an option, do the modification in accordance with Boeing Service Bulletin 777-53-0076 Revision 2. Airplanes that have done Boeing Service Bulletin 777-53A0075 Origi- nal Issue or Revision 1 PART 2 sta- tion 2370 pivot bulkhead forward chord - small crack repair on the left or right side, and have not done the modification in accordance with Boeing Service Bulletin 777-53-0076 on the left or right side. Group 1 and 2, Configuration 3 Do PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULK- HEAD ASSEMBLY STRUCTURE, for any crack at the times specified in Compliance. Airplanes that have done Boeing Service Bulletin 777-53A0075 and have done the modification in accor- dance with Boeing Service Bulletin 777-53-0076. Group 1 and 2, Configuration 4 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 22 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 23 The work in this service bulletin is done in the maintenance zone(s) given below. Group 1: Affected Maintenance Zones ZoneModel 313, 314777-200 Group 2: Affected Maintenance Zones ZoneModel 313, 314777-200, 777-300 E. Compliance Federal Aviation Administration (FAA) Airworthiness Directive AD 2016-09-01 is related to this service bulletin. The effective date of AD 2016-09-01 is June 6, 2016. The Federal Aviation Administration (FAA) will possibly release an additional Airworthiness Directive related to this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin mandatory. 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. Logic diagrams showing compliance tasks and compliance times are included as aids in APPENDIX A, APPENDIX B, APPENDIX C and APPENDIX D. The conditions and associated actions given in the compliance tables below can be different on the left and right sides of the airplane. The actions done must obey the compliance times shown in the compliance tables for each side of the airplane. Because the conditions found may not be the same on both sides of the airplane, the required actions may be different between the left and right side of the airplane and can be done independently. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 23 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 24 Group 1-2, Configuration 1: Table 1: Left and Right Side, DET and HFEC Inspection of the Station 2370 Pivot Bulkhead Forward Outer Chord: Repeat Interval (Not to Exceed) Compliance Time (Whichev- er Occurs Later) ActionCondition -Within 500 flight cycles after the Revi- sion 2 date of this Service Bulletin. Before 4,000 total flight cy- cles or 24,000 total flight hours, whichever oc- curs first. Do PART 1: STATION 2370 PIVOT BULKHEAD FOR- WARD OUTER CHORD AND LONGERON FITTING - DET AND HFEC INSPEC- TION for any crack. All Airplanes. 12,000 flight cycles or 72,000 flight hours, whichever occurs first. -OPTION 1: Repeat PART 1: STATION 2370 PIVOT BULKHEAD FORWARD OUTER CHORD AND LONGERON FITTING - DET AND HFEC INSPEC- TION for any crack. CONDITION 1: NO FORWARD OUTER CHORD CRACK AND NO LONGERON FITTING CRACK IS FOUND. -Before further flight.OPTION 2 (ACTION 1): Do the modification in accor- dance with Boeing Service Bulletin 777-53-0076 Revi- sion 2. At the times specified in Table 4.OPTION 2 (ACTION 2): Do PART 4: POST-MODIFI- CATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FIT- TING AND BULKHEAD AS- SEMBLY STRUCTURE for any crack. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 24 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 25 Group 1-2, Configuration 1: Table 1: Left and Right Side, DET and HFEC Inspection of the Station 2370 Pivot Bulkhead Forward Outer Chord: Repeat Interval (Not to Exceed) Compliance Time (Whichev- er Occurs Later) ActionCondition -Before further flight.CONDITION 2 (ACTION 1):CONDITION 2: Do the modification in accor- dance with Boeing Service Bulletin 777-53-0076 Revi- sion 2. ANY FORWARD OUTER CHORD CRACK IS FOUND AND NO LONGERON FITTING CRACK IS FOUND. At the times specified in Table 4.CONDITION 2 (ACTION 2): Do PART 4: POST-MODIFI- CATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FIT- TING AND BULKHEAD AS- SEMBLY STRUCTURE for any crack. -Before further flight.CONDITION 3 (ACTION 1):CONDITION 3: Contact The Boeing Compa- ny for repair instructions and do the repair. ANY LONGERON FITTING CRACK IS FOUND AND NO FORWARD OUTER CHORD CRACK IS FOUND. 12,000 flight cyclesor 72,000 flight hours, whichever occurs first. -CONDITION 3 (ACTION 2): Repeat PART 1: STATION 2370 PIVOT BULKHEAD FORWARD OUTER CHORD AND LONGERON FITTING - DET AND HFEC INSPEC- TION for any crack.(a) -Before further flight.CONDITION 4 (ACTION 1):CONDITION 4: ANY FOR- WARD CHORD CRACK IS FOUND AND ANY LONGERON FITTING CRACK IS FOUND. Contact The Boeing Compa- ny for repair instructions and do the repair. 12,000 flight cycles or 72,000 flight hours, whichever occurs first. -CONDITION 4 (ACTION 2): Repeat PART 1: STATION 2370 PIVOT BULKHEAD FORWARD OUTER CHORD AND LONGERON FITTING - DET AND HFEC INSPEC- TION for any crack.(a) Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 25 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 26 Group 1-2, Configuration 1: Table 1: Left and Right Side, DET and HFEC Inspection of the Station 2370 Pivot Bulkhead Forward Outer Chord: Repeat Interval (Not to Exceed) Compliance Time (Whichev- er Occurs Later) ActionCondition (a) It is not required to do the STATION 2370 PIVOT BULKHEAD FORWARD OUTER CHORD AND LONGERON FITTING - DET AND HFEC INSPECTION in areas where a repair covers the affected in- spection zone provided: 1. The repair is the corrective action to the crack condition identified in Service Bulletin 777-53A0075 and installed after the Revision 2 date of Service Bulletin 777-53A0075, AND 2. The installed repair was approved by the Boeing Company Organization Designation Authorization (ODA) via a FAA Form 8100-9. Group 1-2, Configuration 2: Table 2: Left and Right Side, DET and HFEC Inspection of the Station 2370 Pivot Bulkhead Forward Outer Chord: Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Within 12,000 flight cycles or 72,000 flight hours after the previous PART 1: STATION 2370 PIVOT BULKHEAD FORWARD CHORD AND LONGERON FITTING - DET AND HFEC INSPECTION in accordance with Revision 1 of this Service Bulletin, whichev- er occurs first. Do PART 1: STATION 2370 PIVOT BULKHEAD FOR- WARD OUTER CHORD AND LONGERON FITTING - DET AND HFEC INSPEC- TION for any crack. All Airplanes. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 26 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 27 Group 1-2, Configuration 2: Table 2: Left and Right Side, DET and HFEC Inspection of the Station 2370 Pivot Bulkhead Forward Outer Chord: Repeat Interval (Not to Exceed) Compliance TimeActionCondition 12,000 flight cycles or 72,000 flight hours, whichever occurs first. -OPTION 1: Repeat PART 1: STATION 2370 PIVOT BULKHEAD FORWARD OUTER CHORD AND LONGERON FITTING - DET AND HFEC INSPEC- TION for any crack. CONDITION 1: NO FORWARD OUTER CHORD CRACK AND NO LONGERON FITTING CRACK IS FOUND. -Before further flight.OPTION 2 (ACTION 1): Do the modification in accor- dance with Boeing Service Bulletin 777-53-0076 Revi- sion 2. At the times specified in Table 4.OPTION 2 (ACTION 2): Do PART 4: POST-MODIFI- CATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FIT- TING AND BULKHEAD AS- SEMBLY STRUCTURE for any crack. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 27 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 28 Group 1-2, Configuration 2: Table 2: Left and Right Side, DET and HFEC Inspection of the Station 2370 Pivot Bulkhead Forward Outer Chord: Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Before further flight.CONDITION 2 (ACTION 1):CONDITION 2: Do the modification in accor- dance with Boeing Service Bulletin 777-53-0076 Revi- sion 2. ANY FORWARD OUTER CHORD CRACK IS FOUND AND NO LONGERON FITTING CRACK IS FOUND. At the times specified in Table 4.CONDITION 2 (ACTION 2): Do PART 4: POST-MODIFI- CATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FIT- TING AND BULKHEAD AS- SEMBLY STRUCTURE for any crack. -Before further flight.CONDITION 3 (ACTION 1):CONDITION 3: Contact The Boeing Compa- ny for repair instructions and do the repair. ANY LONGERON FITTING CRACK IS FOUND AND NO FORWARD OUTER CHORD CRACK IS FOUND. 12,000 flight cyclesor 72,000 flight hours, whichever occurs first. -CONDITION 3 (ACTION 2): Repeat PART 1: STATION 2370 PIVOT BULKHEAD FORWARD OUTER CHORD AND LONGERON FITTING - DET AND HFEC INSPEC- TION for any crack.(a) -Before further flight.CONDITION 4 (ACTION 1):CONDITION 4: ANY FOR- WARD CHORD CRACK IS FOUND AND ANY LONGERON FITTING CRACK IS FOUND. Contact The Boeing Compa- ny for repair instructions and do the repair. 12,000 flight cycles or 72,000 flight hours, whichever occurs first. -CONDITION 4 (ACTION 2): Repeat PART 1: STATION 2370 PIVOT BULKHEAD FORWARD OUTER CHORD AND LONGERON FITTING - DET AND HFEC INSPEC- TION for any crack.(a) Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 28 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 29 Group 1-2, Configuration 2: Table 2: Left and Right Side, DET and HFEC Inspection of the Station 2370 Pivot Bulkhead Forward Outer Chord: Repeat Interval (Not to Exceed) Compliance TimeActionCondition (a) It is not required to do the STATION 2370 PIVOT BULKHEAD FORWARD OUTER CHORD AND LONGERON FITTING - DET AND HFEC INSPECTION in areas where a repair covers the affected in- spection zone provided: 1. The repair is the corrective action to the crack condition identified in Service Bulletin 777-53A0075 and installed after the Revision 2 date of Service Bulletin 777-53A0075, AND 2. The installed repair was approved by the Boeing Company Organization Designation Authorization (ODA) via a FAA Form 8100-9. Group 1-2, Configuration 3: Table 3: Left and Right Side, Post-Repair DET and HFEC Inspection of the STA 2370 Pivot Bulkhead Forward Outer Chord Small Crack Repair: Repeat Interval (Not to Exceed) Compliance Time (Whichev- er Occurs Later) ActionCondition -Within 500 flight cycles after the Revi- sion 2 date of this Service Bulletin. Within 4,000 flight cycles or 24,000 flight hours, whichever oc- curs first after the small crack repair. Do PART 3: SMALL CRACK REPAIR - POST-REPAIR DET AND HFEC INSPEC- TION OF THE STA 2370 PIVOT BULKHEAD FOR- WARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. All airplanes previously re- paired in accordance with PART 2: STATION 2370 PIVOT BULKHEAD FOR- WARD CHORD - SMALL CRACK REPAIR Original Issue or Revision 1 of this service bulletin. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 29 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 30 Group 1-2, Configuration 3: Table 3: Left and Right Side, Post-Repair DET and HFEC Inspection of the STA 2370 Pivot Bulkhead Forward Outer Chord Small Crack Repair: Repeat Interval (Not to Exceed) Compliance Time (Whichev- er Occurs Later) ActionCondition 12,000 flight cycles or 72,000 flight hours, whichever occurs first. -OPTION 1: Repeat PART 3: SMALL CRACK REPAIR - POST- REPAIR DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FIT- TING AND BULKHEAD AS- SEMBLY STRUCTURE for any crack. CONDITION 5: NO FORWARD OUTER CHORD CRACK AND NO LONGERON FITTING CRACK IS FOUND. -Before further flight.OPTION 2 (ACTION 1): Do the modification in accor- dance with Boeing Service Bulletin 777-53-0076 Revi- sion 2. At the times specified in Table 4.OPTION 2 (ACTION 2): Do PART 4: POST-MODIFI- CATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FIT- TING AND BULKHEAD AS- SEMBLY STRUCTURE for any crack. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 30 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 31 Group 1-2, Configuration 3: Table 3: Left and Right Side, Post-Repair DET and HFEC Inspection of the STA 2370 Pivot Bulkhead Forward Outer Chord Small Crack Repair: Repeat Interval (Not to Exceed) Compliance Time (Whichev- er Occurs Later) ActionCondition -Before further flight.CONDITION 6 (ACTION 1):CONDITION 6: Do the modification in accor- dance with Boeing Service Bulletin 777-53-0076 Revi- sion 2. ANY FORWARD OUTER CHORD CRACK IS FOUND AND NO LONGERON FITTING CRACK IS FOUND. At the times specified in Table 4.CONDITION 2 (ACTION 2): Do PART 4: POST-MODIFI- CATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FIT- TING AND BULKHEAD AS- SEMBLY STRUCTURE for any crack. -Before further flight.CONDITION 7 (ACTION 1):CONDITION 7: Contact The Boeing Compa- ny for repair instructions and do the repair. ANY LONGERON FITTING CRACK IS FOUND AND NO FORWARD OUTER CHORD CRACK IS FOUND. 12,000 flight cyclesor 72,000 flight hours, whichever occurs first. -CONDITION 7 (ACTION 2): Repeat PART 3: SMALL CRACK REPAIR - POST- REPAIR DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FIT- TING AND BULKHEAD AS- SEMBLY STRUCTURE for any crack.(a) Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 31 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 32 Group 1-2, Configuration 3: Table 3: Left and Right Side, Post-Repair DET and HFEC Inspection of the STA 2370 Pivot Bulkhead Forward Outer Chord Small Crack Repair: Repeat Interval (Not to Exceed) Compliance Time (Whichev- er Occurs Later) ActionCondition -Before further flight.CONDITION 8 (ACTION 1):CONDITION 8: ANY FOR- WARD CHORD CRACK IS FOUND AND ANY LONGERON FITTING CRACK IS FOUND. Contact The Boeing Compa- ny for repair instructions and do the repair. 12,000 flight cycles or 72,000 flight hours, whichever occurs first. -CONDITION 8 (ACTION 2): Repeat PART 3: SMALL CRACK REPAIR - POST- REPAIR DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FIT- TING AND BULKHEAD AS- SEMBLY STRUCTURE for any crack.(a) (a) It is not required to do the SMALL CRACK REPAIR - POST-REPAIR DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE in areas where a repair covers the affected inspection zone provided: 1. The repair is the corrective action to the crack condition identified in Service Bulletin 777-53A0075 and installed after the Revision 2 date of Service Bulletin 777-53A0075, AND 2. The installed repair was approved by the Boeing Company Organization Designation Authorization (ODA) via a FAA Form 8100-9. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 32 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 33 Group 1-2, Configuration 4: Table 4: Left and Right Side, Post-Modification DET and HFEC Inspection of the STA 2370 Pivot Bulkhead Forward Outer Chord: Repeat Interval (Not to Exceed) Compliance Time (Whichev- er Occurs Later) ActionCondition -Within 12,000 flight cycles or 72,000 flight hours, whichever oc- curs first after the modifica- tion installa- tion; or within 500 flight cy- cles after the Revision 2 date of this Service Bul- letin; whichever oc- curs later. Before 30,000 total flight cy- cles or 180,000 total flight hours, whichever oc- curs first. Do PART 4: POST-MODIFI- CATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FIT- TING AND BULKHEAD AS- SEMBLY STRUCTURE for any crack. All airplanes at the location previously modified in ac- cordance with Boeing Ser- vice Bulletin 777-53-0076. 12,000 flight cycles or 72,000 flight hours, whichever occurs first. -Repeat PART 4: POST- MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. CONDITION 9: NO FORWARD OUTER CHORD CRACK AND NO LONGERON FITTING CRACK IS FOUND. -Before further flight.CONDITION 10 (ACTION 1):CONDITION 10: Do the modification in accor- dance with Boeing Service Bulletin 777-53-0076 Revi- sion 2. ANY FORWARD OUTER CHORD CRACK IS FOUND AND NO LONGERON FITTING CRACK IS FOUND. 12,000 flight cycles or 72,000 flight hours, whichever occurs first. -CONDITION 10 (ACTION 2): Repeat PART 4: POST- MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 33 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 34 Group 1-2, Configuration 4: Table 4: Left and Right Side, Post-Modification DET and HFEC Inspection of the STA 2370 Pivot Bulkhead Forward Outer Chord: Repeat Interval (Not to Exceed) Compliance Time (Whichev- er Occurs Later) ActionCondition -Before further flight.CONDITION 11 (ACTION 1):CONDITION 11: Contact The Boeing Compa- ny for repair instructions and do the repair. ANY LONGERON FITTING CRACK IS FOUND AND NO FORWARD OUTER CHORD CRACK IS FOUND. 12,000 flight cyclesor 72,000 flight hours, whichever occurs first. -CONDITION 11 (ACTION 2): Repeat PART 4: POST- MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack.(a) -Before further flight.CONDITION 12 (ACTION 1):CONDITION 12: ANY FORWARD CHORD CRACK IS FOUND AND ANY LONGERON FITTING CRACK IS FOUND. Contact The Boeing Compa- ny for repair instructions and do the repair. 12,000 flight cycles or 72,000 flight hours, whichever occurs first. -CONDITION 12 (ACTION 2): Repeat PART 4: POST- MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack.(a) (a) It is not required to do the POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE in areas where a repair covers the affected inspection zone provided: 1. The repair is the corrective action to the crack condition identified in Service Bulletin 777-53A0075 and installed after the Revision 2 date of Service Bulletin 777-53A0075, AND 2. The installed repair was approved by the Boeing Company Organization Designation Authorization (ODA) via a FAA Form 8100-9. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 34 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 35 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 Union 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. In addition, the Manager of the FAA Seattle ACO Branch approves the accomplishment of the inspections and related corrective actions specified in this service bulletin as an alternative method of compliance to the requirements of paragraph (g) and (h) of AD 2016-09-01. All provisions of AD 2016-09-01 that are not specifically referenced in the above statement remain fully applicable and must be complied with accordingly. G. Manpower The tables below show 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. Group 1, Configuration 1-2; Group 2, Configuration 1-2: Table 1: Manpower Information for PART 1: STATION 2370 PIVOT BULKHEAD FORWARD OUTER CHORD AND LONGERON FITTING - DET AND HFEC INSPECTION Elapsed HoursTask HoursNumber of PersonsTask Open Access 2.002.001FIGURE 1 2.002.001FIGURE 2 PART 1: STATION 2370 PIVOT BULKHEAD FORWARD OUTER CHORD AND LONGERON FITTING - DET AND HFEC INSPECTION 1.501.501FIGURE 3 1.501.501FIGURE 4 Close Access 2.004.002FIGURE 5 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 35 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 36 Group 1, Configuration 1-2; Group 2, Configuration 1-2: Table 1: Manpower Information for PART 1: STATION 2370 PIVOT BULKHEAD FORWARD OUTER CHORD AND LONGERON FITTING - DET AND HFEC INSPECTION Elapsed HoursTask HoursNumber of PersonsTask 2.004.002FIGURE 6 11.0015.00TOTAL FOR EACH AIRPLANE Group 1, Configuration 3: Table 2: Manpower Information for PART 3: SMALL CRACK REPAIR - POST-REPAIR DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE Elapsed HoursTask HoursNumber of PersonsTask Open Access 2.002.001FIGURE 25 2.002.001FIGURE 26 0.250.251FIGURE 27 0.250.251FIGURE 28 DET and HFEC Inspection 0.750.751FIGURE 11 0.750.751FIGURE 12 1.251.251FIGURE 19 1.251.251FIGURE 20 Close Access 1.002.002FIGURE 21 1.002.002FIGURE 22 0.130.252FIGURE 29 0.130.252FIGURE 30 10.7513.00TOTAL FOR EACH AIRPLANE Group 2, Configuration 3: Table 2: Manpower Information for PART 3: SMALL CRACK REPAIR - POST-REPAIR DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE Elapsed HoursTask HoursNumber of PersonsTask Open Access 2.002.001FIGURE 25 2.002.001FIGURE 26 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 36 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 37 Group 2, Configuration 3: Table 2: Manpower Information for PART 3: SMALL CRACK REPAIR - POST-REPAIR DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE Elapsed HoursTask HoursNumber of PersonsTask 0.250.251FIGURE 27 0.250.251FIGURE 28 DET and HFEC Inspection 0.750.751FIGURE 11 0.750.751FIGURE 12 1.251.251FIGURE 19 1.251.251FIGURE 20 Close Access 1.002.002FIGURE 21 1.002.002FIGURE 22 0.130.252FIGURE 31 0.130.252FIGURE 32 10.7513.00TOTAL FOR EACH AIRPLANE Group 1, Configuration 4: Table 3: Manpower Information for PART 4: POST-MODIFICATION DET AND HFEC INSPEC- TION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE Elapsed HoursTask HoursNumber of PersonsTask Open Access 2.002.001FIGURE 1 2.002.001FIGURE 2 0.250.251FIGURE 27 0.250.251FIGURE 28 PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE 1.501.501FIGURE 3 1.501.501FIGURE 4 0.750.751FIGURE 11 0.750.751FIGURE 12 Close Access Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 37 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 38 Group 1, Configuration 4: Table 3: Manpower Information for PART 4: POST-MODIFICATION DET AND HFEC INSPEC- TION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE Elapsed HoursTask HoursNumber of PersonsTask 2.004.002FIGURE 5 2.004.002FIGURE 6 0.130.252FIGURE 29 0.130.252FIGURE 30 13.2517.50TOTAL FOR EACH AIRPLANE Group 2, Configuration 4: Table 3: Manpower Information for PART 4: POST-MODIFICATION DET AND HFEC INSPEC- TION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE Elapsed HoursTask HoursNumber of PersonsTask Open Access 2.002.001FIGURE 1 2.002.001FIGURE 2 0.250.251FIGURE 27 0.250.251FIGURE 28 PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE 1.501.501FIGURE 3 1.501.501FIGURE 4 0.750.751FIGURE 11 0.750.751FIGURE 12 Close Access 2.004.002FIGURE 5 2.004.002FIGURE 6 0.130.252FIGURE 31 0.130.252FIGURE 32 13.2517.50TOTAL FOR EACH AIRPLANE Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 38 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 39 H. Weight and Balance Changes Weight and Balance changes affected by incorporation of this service bulletin are dependent on the inspection, number of flight cycles, condition, type, number and location of repairs/modification done on each particular airplane. Weight and Balance are to be calculated by the operator by weighing parts installed or removed. Operators should make necessary revisions to the appropriate weight and balance report. I. Electrical Load Data Not changed. J. References 1. Existing Data: a. Engineering Change Memo PRR 62777-97S, PRR 62685-R b. Boeing Service Bulletin 777-53-0076, 777-53A0075 c. Boeing Service Letter 777-SL-51-013 d. Boeing Service Related Problem (SRP) 777-SRP-53-0455, 777-SRP-53-0620 e. Federal Aviation Administration (FAA) Airworthiness Directive (AD) 2016-09-01 f. Service Bulletin Index D624W001 g. Standard Overhaul Practices Manual (SOPM) 20-50-01, 20-50-19 h. 777 Fleet Team Digest (FTD) 53-13001, 53-20001 i. 777 Non-Destructive Testing (NDT) Manual Part 6, 51-00-01, Part 6, 51-00-02 2. Data Supplied with this Service Bulletin: None. 3. Installation Drawings Used in the Preparation of this Service Bulletin: TitleDrawing Number Bulkhead Instl - Upr, Pivot and Skin, STA 2370148W2010 Fairing Instl - Stabilizer Seal, UPR148W2910 Bulkhead Instl - Pivot, Integration, STA 2370148W9700 The table above lists applicable drawings used to prepare this service bulletin. The drawings are not necessary to make the specified changes, and are not supplied with this service bulletin. The drawings may not be applicable to all airplane configurations or operators. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 39 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 40 K. Publications Affected 1. Publications: Chapter-SectionPublication 53-80777 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. DTI requirements for the structure affected are contained in Paragraph 1.E., Compliance of this service bulletin. 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: January 14, 2015 777-53A0075Revision 2: February 22, 2021 40 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 41 2. MATERIAL INFORMATION A. Material - Price and Availability Boeing can supply the kits 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 kits 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 Revision 2 date of this Ser- vice Bulletin (US Dollars) ROLT as of the Revision 2 date of this Service Bul- letin (Calendar Days) NameKit Number --Top Kit - STA 2370 Pivot Bulkhead Forward Outer Chord - Inspection Restoration 005W0016-10 (a) --Top Kit - STA 2370 Pivot Bulkhead Forward Outer Chord, Left - Small Crack 005W0016-11 (a) --Top Kit - STA 2370 Pivot Bulkhead Forward Outer Chord, Right - Small Crack 005W0016-12 (a) $28.00335SUPPLEMENTAL KIT - STA 2370 Pivot Bulk- head Forward Outer Chord - Inspection 005W0016-16 (b) $290.00335REPLACEMENT KIT - STA 2370 Pivot Bulkhead Forward Outer Chord - Inspection 005W0016-17 (a) This top kit is no longer available. (b) 005W0016-16 is a Supplemental Kit for 005W0016-10 Top Kit. 005W0016-16 plus 005W0016-10 is equivalent to 005W0016-17 Replacement Kit. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 41 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 42 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 Revision 2 date of this Ser- vice Bulletin (US Dollars) ROLT as of the Revision 2 date of this Service Bul- letin (Calendar Days) NameKit Number --Top Kit - STA 2370 Pivot Bulkhead Forward Outer Chord - Inspection Restoration 005W0016-10 (a) --Top Kit - STA 2370 Pivot Bulkhead Forward Outer Chord, Left - Small Crack 005W0016-11 (a) --Top Kit - STA 2370 Pivot Bulkhead Forward Outer Chord, Right - Small Crack 005W0016-12 (a) $28.00335SUPPLEMENTAL KIT - STA 2370 Pivot Bulk- head Forward Outer Chord - Inspection 005W0016-18 (b) $330.00335REPLACEMENT KIT - STA 2370 Pivot Bulkhead Forward Outer Chord - Inspection 005W0016-19 (a) This top kit is no longer available. (b) 005W0016-18 is a Supplemental Kit for 005W0016-10 Top Kit. 005W0016-18 plus 005W0016-10 is equivalent to 005W0016-19 Replacement Kit. Operators are encouraged to complete the survey provided in APPENDIX E of this service bulletin to help Boeing predict the quantity and timing of the Boeing Supplied Kits/Parts. B. Industry Support Information Boeing warranty remedies are available for 777 airplanes in warranty as of November 20, 2013. For inspection labor task hour reimbursement for airplanes in warranty as of that date, send a warranty claim to BCA Contracts - Warranty. 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, kits, and/or parts are required, send a warranty claim to BCA Contracts - Warranty. The warranty remedies will expire eight years from the original issue date of this service bulletin. C. Parts Necessary for Each Airplane 1. Kits/Parts To get the kits/parts shown below, refer to Paragraph 2.A., Material - Price and Availability. NOTE: One top kit and the items shown in Paragraph 2.C.2., Parts and Materials Supplied by the Operator, are necessary for each airplane, except as noted in Paragraph 2.A., Material - Price and Availability. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 42 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 43 ALL Kit 005W0016 NotesExisting Part Number NameQtyNew Part Number -19 -17 (a)-REPLACEMENT KIT - STA 2370 Pivot Bulkhead Forward Outer Chord - Inspection . -005W0016-17 (a)-REPLACEMENT KIT - STA 2370 Pivot Bulkhead Forward Outer Chord - Inspection - .005W0016-19 (b)-BOLT, 100 DEG HEX DR 4 4BACB30NW6K5X (b)-BOLT, 100 DEG HEX DR 14 14BACB30NW8K5X (b)-BOLT, 100 DEG HEX DR 2 2BACB30NW8K6X (b)-BOLT, 100 DEG HEX DR 12 8BACB30NW8K9X --COLLAR4 4BACC30M6 --COLLAR28 24BACC30M8 (b)-RIVET, 100 DEG6 6BACR15CE5KE5 (b)-RIVET, 100 DEG12 12BACR15CE5KE6 (b)-RIVET, 100 DEG2 2BACR15CE5KE8 (b)-RIVET . 4BACR15FV81KE13 (a) This top kit is for restoration after inspection. (b) If grip length shown is not available at Boeing, fasteners supplied in kits may be one grip length longer than indicated. Also, if any fasteners part numbers listed are not available or have been superseded, substitute fasteners may be supplied in kits. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 43 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 44 ALL Kit 005W0016 NotesExisting Part Number NameQtyNew Part Number -18 -16 --SUPPLEMENTAL KIT - STA 2370 Pivot Bulkhead Forward Outer Chord - Inspection . -005W0016-16 --SUPPLEMENTAL KIT - STA 2370 Pivot Bulkhead Forward Outer Chord - Inspection - .005W0016-18 (a)-BOLT, 100 DEG HEX DR 4 .BACB30NW8K9X --COLLAR4 .BACC30M8 (a)-RIVET . 4BACR15FV81KE13 (a) If grip length shown is not available at Boeing, fasteners supplied in kits may be one grip length longer than indicated. Also, if any fasteners part numbers listed are not available or have been superseded, substitute fasteners may be supplied in kits. 2. Parts and Materials Supplied by the Operator The following parts or materials are necessary to do the change in this service bulletin. Parts and materials in the manuals given in Paragraph 1.J., References, can also be necessary. Examine operator part and material supply to make sure all necessary parts and materials are available. NotesNameQTYPart Number / Specification (a)(b)Sealant1 PintBMS 5-95 (a) Refer to the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier data. (b) May be purchased from: Boeing Distribution Incorporated (Cage 22819) 2750 Regent Boulevard, Dallas, Texas 75261. Website: https://shop.boeing.com/aviation-supply 3. Parts Modified and Reidentified The parts shown below are changed as shown in this service bulletin. The quantity (QTY) is the number of parts changed on each airplane. None. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 44 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 45 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: January 14, 2015 777-53A0075Revision 2: February 22, 2021 45 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 46 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 46 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT BLANK PAGE ### Page 47 3. ACCOMPLISHMENT INSTRUCTIONS A. GENERAL INFORMATION 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. CAUTION 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. Use the approved fastener, process and 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. Refer to SOPM 20-50-01 for alternate full threaded fasteners (screws) needed for installation in this service bulletin. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 47 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 48 6. A Detailed (DET) Inspection is defined as: An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. This could include tactile assessment in which a component or assembly can be checked for tightness/security. 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. HFEC is used for a High Frequency Eddy Current Inspection. 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. 9. 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. 10. Refer to Appendix A, Appendix B, Appendix C, and Appendix D for logic diagram(s). Logic diagrams are provided as an aid only. Information contained in Paragraph 1.E., Compliance is the primary source for compliance times. Information in Paragraph 3.B., Work Instructions is the primary source for tasks required for compliance. 11. 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. 12. 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. 13. 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. 14. Use of colors in Figures is based on guidance from the ATA e-Business Program (ATA) iSpec 2200. 15. 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 or an OPTION, do all of the ACTION numbers for that CONDITION or OPTION. 16. The compliance times for the actions in Paragraph 3.B., WORK INSTRUCTIONS are in Paragraph 1.E., Compliance. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 48 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 49 17. The conditions and associated actions given in Paragraph 3.B., Work Instructions can be different on the left and right sides of the airplane. Because the conditions found may not be the same on both sides of the airplane, the required actions may be different between the left and right side of the airplane and can be done independently. 18. Some steps in the Work Instructions are labeled as Required for Compliance (RC). If this service bulletin is mandated by an Airworthiness Directive (AD), then the steps labeled as RC, including sub-steps under an RC step and any figures identified in an RC step, must be done to comply with the AD. If a step or sub-step is labeled "RC Exempt," then the RC requirement is removed from that step or sub-step. An Alternative Method of Compliance (AMOC) is required for any deviations to RC steps, including sub-steps and identified figures. Steps not labeled as RC may be deviated from using accepted methods in accordance with the operator's maintenance or inspection program without obtaining approval of an AMOC. This is provided that the RC steps, including sub-steps and identified figures, can still be done as specified, and the airplane can be put back in an airworthy condition. B. WORK INSTRUCTIONS 1. Group 1, Configuration 1-2, 4; Group 2, Configuration 1-2, 4: Remove the skin panels in accordance with the figures below: Right SideLeft Side FIGURE 2FIGURE 1 2. Group 1, Configuration 1-2; Group 2, Configuration 1-2: RC - Do PART 1: STATION 2370 PIVOT BULKHEAD FORWARD OUTER CHORD AND LONGERON FITTING - DET AND HFEC INSPECTION, for any crack. a. CONDITION 1: NO FORWARD OUTER CHORD CRACK AND NO LONGERON FITTING CRACK IS FOUND. (1) OPTION 1: Repeat PART 1: STATION 2370 PIVOT BULKHEAD FORWARD OUTER CHORD AND LONGERON FITTING - DET AND HFEC INSPECTION, for any crack. (2) OPTION 2 (ACTION 1): Do the modification in accordance with Boeing Service Bulletin 777-53-0076 Revision 2. (3) OPTION 2 (ACTION 2): Do PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. (a) CONDITION 9: NO FORWARD OUTER CHORD CRACK AND NO LONGERON FITTING CRACK IS FOUND. 1) Repeat PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 49 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 50 (b) CONDITION 10: ANY FORWARD OUTER CHORD CRACK IS FOUND AND NO LONGERON FITTING CRACK IS FOUND. 1) CONDITION 10 (ACTION 1): Do the modification in accordance with Boeing Service Bulletin 777-53-0076 Revision 2. 2) CONDITION 10 (ACTION 2): Repeat PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. (c) CONDITION 11: ANY LONGERON FITTING CRACK IS FOUND AND NO FORWARD OUTER CHORD CRACK IS FOUND. 1) CONDITION 11 (ACTION 1): Contact The Boeing Company for repair instructions and do the repair. 2) CONDITION 11 (ACTION 2): Repeat PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. a) It is not required to do the POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE in areas where a repair covers the affected inspection zone provided: {1} The repair is the corrective action to the crack condition identified in Service Bulletin 777-53A0075 and installed after the Revision 2 date of Service Bulletin 777-53A0075, AND {2} The installed repair was approved by the Boeing Company Organization Designation Authorization (ODA) via a FAA Form 8100-9. (d) CONDITION 12: ANY FORWARD CHORD CRACK IS FOUND AND ANY LONGERON FITTING CRACK IS FOUND. 1) CONDITION 12 (ACTION 1): Contact The Boeing Company for repair instructions and do the repair. 2) CONDITION 12 (ACTION 2): Repeat PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. a) It is not required to do the POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE in areas where a repair covers the affected inspection zone provided: Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 50 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 51 {1} The repair is the corrective action to the crack condition identified in Service Bulletin 777-53A0075 and installed after the Revision 2 date of Service Bulletin 777-53A0075, AND {2} The installed repair was approved by the Boeing Company Organization Designation Authorization (ODA) via a FAA Form 8100-9. b. CONDITION 2: ANY FORWARD OUTER CHORD CRACK IS FOUND AND NO LONGERON FITTING CRACK IS FOUND. (1) CONDITION 2 (ACTION 1): Do the modification in accordance with Boeing Service Bulletin 777-53-0076 Revision 2. (2) CONDITION 2 (ACTION 2): Do PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. (a) CONDITION 9: NO FORWARD OUTER CHORD CRACK AND NO LONGERON FITTING CRACK IS FOUND. 1) Repeat PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. (b) CONDITION 10: ANY FORWARD OUTER CHORD CRACK IS FOUND AND NO LONGERON FITTING CRACK IS FOUND. 1) CONDITION 10 (ACTION 1): Do the modification in accordance with Boeing Service Bulletin 777-53-0076 Revision 2. 2) CONDITION 10 (ACTION 2): Repeat PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. (c) CONDITION 11: ANY LONGERON FITTING CRACK IS FOUND AND NO FORWARD OUTER CHORD CRACK IS FOUND. 1) CONDITION 11 (ACTION 1): Contact The Boeing Company for repair instructions and do the repair. 2) CONDITION 11 (ACTION 2): Repeat PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. a) It is not required to do the POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE in areas where a repair covers the affected inspection zone provided: Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 51 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 52 {1} The repair is the corrective action to the crack condition identified in Service Bulletin 777-53A0075 and installed after the Revision 2 date of Service Bulletin 777-53A0075, AND {2} The installed repair was approved by the Boeing Company Organization Designation Authorization (ODA) via a FAA Form 8100-9. (d) CONDITION 12: ANY FORWARD CHORD CRACK IS FOUND AND ANY LONGERON FITTING CRACK IS FOUND. 1) CONDITION 12 (ACTION 1): Contact The Boeing Company for repair instructions and do the repair. 2) CONDITION 12 (ACTION 2): Repeat PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. a) It is not required to do the POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE in areas where a repair covers the affected inspection zone provided: {1} The repair is the corrective action to the crack condition identified in Service Bulletin 777-53A0075 and installed after the Revision 2 date of Service Bulletin 777-53A0075, AND {2} The installed repair was approved by the Boeing Company Organization Designation Authorization (ODA) via a FAA Form 8100-9. c. CONDITION 3: ANY LONGERON FITTING CRACK IS FOUND AND NO FORWARD OUTER CHORD CRACK IS FOUND. (1) CONDITION 3 (ACTION 1): Contact The Boeing Company for repair instructions and do the repair. (2) CONDITION 3 (ACTION 2): Repeat PART 1: STATION 2370 PIVOT BULKHEAD FORWARD OUTER CHORD AND LONGERON FITTING - DET AND HFEC INSPECTION, for any crack. (a) It is not required to do the STATION 2370 PIVOT BULKHEAD FORWARD OUTER CHORD AND LONGERON FITTING - DET AND HFEC INSPECTION in areas where a repair covers the affected inspection zone provided: 1) The repair is the corrective action to the crack condition identified in Service Bulletin 777-53A0075 and installed after the Revision 2 date of Service Bulletin 777-53A0075, AND 2) The installed repair was approved by the Boeing Company Organization Designation Authorization (ODA) via a FAA Form 8100-9. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 52 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 53 d. CONDITION 4: ANY FORWARD CHORD CRACK IS FOUND AND ANY LONGERON FITTING CRACK IS FOUND. (1) CONDITION 4 (ACTION 1): Contact The Boeing Company for repair instructions and do the repair. (2) CONDITION 4 (ACTION 2): Repeat PART 1: STATION 2370 PIVOT BULKHEAD FORWARD OUTER CHORD AND LONGERON FITTING- DET AND HFEC INSPECTION for any crack. (a) It is not required to do the STATION 2370 PIVOT BULKHEAD FORWARD OUTER CHORD AND LONGERON FITTING - DET AND HFEC INSPECTION in areas where a repair covers the affected inspection zone provided: 1) The repair is the corrective action to the crack condition identified in Service Bulletin 777-53A0075 and installed after the Revision 2 date of Service Bulletin 777-53A0075, AND 2) The installed repair was approved by the Boeing Company Organization Designation Authorization (ODA) via a FAA Form 8100-9. 3. Group 1-2, Configuration 3: RC - Do PART 3: SMALL CRACK REPAIR - POST-REPAIR DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. a. CONDITION 5: NO FORWARD OUTER CHORD CRACK AND NO LONGERON FITTING CRACK IS FOUND. (1) OPTION 1: Repeat PART 3: SMALL CRACK REPAIR - POST-REPAIR DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. (2) OPTION 2 (ACTION 1): Do the modification in accordance with Boeing Service Bulletin 777-53-0076 Revision 2. (3) OPTION 2 (ACTION 2): Do PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. (a) CONDITION 9: NO FORWARD OUTER CHORD CRACK AND NO LONGERON FITTING CRACK IS FOUND. 1) Repeat PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. (b) CONDITION 10: ANY FORWARD OUTER CHORD CRACK IS FOUND AND NO LONGERON FITTING CRACK IS FOUND. 1) CONDITION 10 (ACTION 1): Do the modification in accordance with Boeing Service Bulletin 777-53-0076 Revision 2. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 53 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 54 2) CONDITION 10 (ACTION 2): Repeat PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. (c) CONDITION 11: ANY LONGERON FITTING CRACK IS FOUND AND NO FORWARD OUTER CHORD CRACK IS FOUND. 1) CONDITION 11 (ACTION 1): Contact The Boeing Company for repair instructions and do the repair. 2) CONDITION 11 (ACTION 2): Repeat PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. a) It is not required to do the POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE in areas where a repair covers the affected inspection zone provided: {1} The repair is the corrective action to the crack condition identified in Service Bulletin 777-53A0075 and installed after the Revision 2 date of Service Bulletin 777-53A0075, AND {2} The installed repair was approved by the Boeing Company Organization Designation Authorization (ODA) via a FAA Form 8100-9. (d) CONDITION 12: ANY FORWARD CHORD CRACK IS FOUND AND ANY LONGERON FITTING CRACK IS FOUND. 1) CONDITION 12 (ACTION 1): Contact The Boeing Company for repair instructions and do the repair. 2) CONDITION 12 (ACTION 2): Repeat PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. a) It is not required to do the POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE in areas where a repair covers the affected inspection zone provided: {1} The repair is the corrective action to the crack condition identified in Service Bulletin 777-53A0075 and installed after the Revision 2 date of Service Bulletin 777-53A0075, AND {2} The installed repair was approved by the Boeing Company Organization Designation Authorization (ODA) via a FAA Form 8100-9. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 54 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 55 b. CONDITION 6: ANY FORWARD OUTER CHORD CRACK IS FOUND AND NO LONGERON FITTING CRACK IS FOUND. (1) CONDITION 6 (ACTION 1): Do the modification in accordance with Boeing Service Bulletin 777-53-0076 Revision 2. (2) CONDITION 6 (ACTION 2): Do PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. (a) CONDITION 9: NO FORWARD OUTER CHORD CRACK AND NO LONGERON FITTING CRACK IS FOUND. 1) Repeat PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. (b) CONDITION 10: ANY FORWARD OUTER CHORD CRACK IS FOUND AND NO LONGERON FITTING CRACK IS FOUND. 1) CONDITION 10 (ACTION 1): Do the modification in accordance with Boeing Service Bulletin 777-53-0076 Revision 2. 2) CONDITION 10 (ACTION 2): Repeat PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. (c) CONDITION 11: ANY LONGERON FITTING CRACK IS FOUND AND NO FORWARD OUTER CHORD CRACK IS FOUND. 1) CONDITION 11 (ACTION 1): Contact The Boeing Company for repair instructions and do the repair. 2) CONDITION 11 (ACTION 2): Repeat PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. a) It is not required to do the POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE in areas where a repair covers the affected inspection zone provided: {1} The repair is the corrective action to the crack condition identified in Service Bulletin 777-53A0075 and installed after the Revision 2 date of Service Bulletin 777-53A0075, AND {2} The installed repair was approved by the Boeing Company Organization Designation Authorization (ODA) via a FAA Form 8100-9. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 55 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 56 (d) CONDITION 12: ANY FORWARD CHORD CRACK IS FOUND AND ANY LONGERON FITTING CRACK IS FOUND. 1) CONDITION 12 (ACTION 1): Contact The Boeing Company for repair instructions and do the repair. 2) CONDITION 12 (ACTION 2): Repeat PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. a) It is not required to do the POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE in areas where a repair covers the affected inspection zone provided: {1} The repair is the corrective action to the crack condition identified in Service Bulletin 777-53A0075 and installed after the Revision 2 date of Service Bulletin 777-53A0075, AND {2} The installed repair was approved by the Boeing Company Organization Designation Authorization (ODA) via a FAA Form 8100-9. c. CONDITION 7: ANY LONGERON FITTING CRACK IS FOUND AND NO FORWARD OUTER CHORD CRACK IS FOUND. (1) CONDITION 7 (ACTION 1): Contact The Boeing Company for repair instructions and do the repair. (2) CONDITION 7 (ACTION 2): Repeat PART 3: SMALL CRACK REPAIR - POST-REPAIR DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. (a) It is not required to do the SMALL CRACK REPAIR - POST-REPAIR DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE in areas where a repair covers the affected inspection zone provided: 1) The repair is the corrective action to the crack condition identified in Service Bulletin 777-53A0075 and installed after the Revision 2 date of Service Bulletin 777-53A0075, AND 2) The installed repair was approved by the Boeing Company Organization Designation Authorization (ODA) via a FAA Form 8100-9. d. CONDITION 8: ANY FORWARD CHORD CRACK IS FOUND AND ANY LONGERON FITTING CRACK IS FOUND. (1) CONDITION 8 (Action 1): Contact The Boeing Company for repair instructions and do the repair. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 56 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 57 (2) CONDITION 8 (Action 2): Repeat PART 3: SMALL CRACK REPAIR - POST-REPAIR DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. (a) It is not required to do the SMALL CRACK REPAIR - POST-REPAIR DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE in areas where a repair covers the affected inspection zone provided: 1) The repair is the corrective action to the crack condition identified in Service Bulletin 777-53A0075 and installed after the Revision 2 date of Service Bulletin 777-53A0075, AND 2) The installed repair was approved by the Boeing Company Organization Designation Authorization (ODA) via a FAA Form 8100-9. 4. Group 1-2, Configuration 4: RC - Do PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. a. CONDITION 9: NO FORWARD OUTER CHORD CRACK AND NO LONGERON FITTING CRACK IS FOUND. (1) Repeat PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. b. CONDITION 10: ANY FORWARD OUTER CHORD CRACK IS FOUND AND NO LONGERON FITTING CRACK IS FOUND. (1) CONDITION 10 (ACTION 1): Do the modification in accordance with Boeing Service Bulletin 777-53-0076 Revision 2. (2) CONDITION 10 (ACTION 2): Repeat PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. c. CONDITION 11: ANY LONGERON FITTING CRACK IS FOUND AND NO FORWARD OUTER CHORD CRACK IS FOUND. (1) CONDITION 11 (ACTION 1): Contact The Boeing Company for repair instructions and do the repair. (2) CONDITION 11 (ACTION 2): Repeat PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. (a) It is not required to do the POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE in areas where a repair covers the affected inspection zone provided: Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 57 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 58 1) The repair is the corrective action to the crack condition identified in Service Bulletin 777-53A0075 and installed after the Revision 2 date of Service Bulletin 777-53A0075, AND 2) The installed repair was approved by the Boeing Company Organization Designation Authorization (ODA) via a FAA Form 8100-9. d. CONDITION 12: ANY FORWARD CHORD CRACK IS FOUND AND ANY LONGERON FITTING CRACK IS FOUND. (1) CONDITION 12 (ACTION 1): Contact The Boeing Company for repair instructions and do the repair. (2) CONDITION 12 (ACTION 2): Repeat PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE for any crack. (a) It is not required to do the POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE in areas where a repair covers the affected inspection zone provided: 1) The repair is the corrective action to the crack condition identified in Service Bulletin 777-53A0075 and installed after the Revision 2 date of Service Bulletin 777-53A0075, AND 2) The installed repair was approved by the Boeing Company Organization Designation Authorization (ODA) via a FAA Form 8100-9. 5. Group 1, Configuration 1-2, 4; Group 2, Configuration 1-2, 4: If not previously installed, install the skin panels in accordance with the figures below: Right SideLeft Side FIGURE 6FIGURE 5 6. Put the airplane back to a serviceable condition. PART 1: STATION 2370 PIVOT BULKHEAD FORWARD OUTER CHORD AND LONGERON FITTING - DET AND HFEC INSPECTION 1. Do an inspection of the Pivot Bulkhead Forward Outer Chord and Longeron Fitting, for any crack, in accordance with the figures below: Right SideLeft Side FIGURE 4FIGURE 3 PART 2: STATION 2370 PIVOT BULKHEAD FORWARD CHORD - SMALL CRACK REPAIR 1. PART 2: STATION 2370 PIVOT BULKHEAD FORWARD OUTER CHORD - SMALL CRACK REPAIR is deleted and is no longer applicable to this revision. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 58 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 59 PART 3: SMALL CRACK REPAIR - POST-REPAIR DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE 1. Remove the skin panels and fasteners in accordance with the figures below: Right SideLeft Side FIGURE 26FIGURE 25 FIGURE 28FIGURE 27 2. Do the DET and HFEC inspection of the Pivot Bulkhead Forward Outer Chord, Longeron Fitting and Bulkhead Assembly Structure, in accordance with the figures below: Right SideLeft Side FIGURE 12FIGURE 11 FIGURE 20FIGURE 19 3. Install the skin panels and fasteners in accordance with the figures below: Right SideLeft Side FIGURE 22FIGURE 21 Group 1, Configuration 3: Right SideLeft Side FIGURE 30FIGURE 29 Group 2, Configuration 3: Right SideLeft Side FIGURE 32FIGURE 31 4. Put the airplane back to a serviceable condition. PART 4: POST-MODIFICATION DET AND HFEC INSPECTION OF THE STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD, LONGERON FITTING AND BULKHEAD ASSEMBLY STRUCTURE 1. Remove the fasteners in accordance with the figures below: Right SideLeft Side FIGURE 28FIGURE 27 2. Do an inspection of the Pivot Bulkhead Forward Outer Chord and Longeron Fitting, for any crack, in accordance with the figures below: Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 59 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT ### Page 60 Right SideLeft Side FIGURE 4FIGURE 3 3. Do the HFEC inspection of the Pivot Bulkhead Assembly Structure in accordance with the figures below: Right SideLeft Side FIGURE 12FIGURE 11 4. Install the fasteners in accordance with the figures below: Group 1, Configuration 4: Right SideLeft Side FIGURE 30FIGURE 29 Group 2, Configuration 4: Right SideLeft Side FIGURE 32FIGURE 31 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 14, 2015 777-53A0075Revision 2: February 22, 2021 60 of 156 BOEING SERVICE BULLETIN 777-53A0075 ALERTALERT The text continues at https://openairdocs.org/service-documents/boeing/777-53a0075/file/58cc9cc0f991.md?from=61 --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain, except the copies of manufacturers’ service documents, which belong to their rights holders.