# Boeing Alert Service Bulletin 747-53A2473: Boeing - Service Bulletin - Rights: © The Boeing Company. Filed by the FAA in regulations.gov docket FAA-2013-0425; AD 2014-07-01 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. - Document: [Boeing Alert Service Bulletin 747-53A2473](https://openairdocs.org/service-documents/boeing/747-53a2473.md) - Title as filed: Boeing - Service Bulletin - Pages: 250 - PDF: https://openairdocs.org/files/sha256/6c/7a/6c7ad8329392be6bba30ee77f477049ea95cf6b1bdef0421341231a038d79d5d - Page: https://openairdocs.org/service-documents/boeing/747-53a2473/file/6c7ad8329392 ## 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 747 Service Bulletin Number: 747-53A2473 Original Issue: March 24, 2005 Revision 4: December 01, 2011 ATA System: 5313 SUBJECT: FUSELAGE - Section 48 - Body Station 2598 Bulkhead - Horizontal Stabilizer Hinge Support Frame Cracking - Modification and Repair Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15 CFR 730-774). An export license may be required before it is used for development, production or use by foreign persons from specific countries. The controller of this data has the individual responsibility to abide by all export laws. 9E991ECCN: BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET Copyright © 2005 The Boeing Company Unpublished Work - All Rights Reserved Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable subject matter. Boeing also claims copyright in this document as a compilation and/or collective work. This document includes proprietary information owned by The Boeing Company and/or one or more third parties. Treatment of the document and the information it contains is governed by contract with Boeing. For more information, contact The Boeing Company, P.O. Box 3707, Seattle, Washington 98124. Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, Dreamliner, BBJ, DC-8, DC-9, DC-10, KC-10, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8A, Poseidon and the Boeing livery are all trademarks owned by The Boeing Company; and no trademark license is granted in connection with this document unless provided in writing by Boeing. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 1 of 250 3.0 ### Page 2 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 2 of 250 BOEING SERVICE BULLETIN 747-53A2473 BLANK PAGE ### Page 3 Table of Contents Revision Transmittal Sheet ............................................ 7 Summary ...................................................... 9 1. PLANNING INFORMATION ........................................ 1 5 A. Effectivity ............................................... 1 5 1. Airplanes ............................................ 1 5 2. Spares Affected ........................................ 2 6 B. Concurrent Requirements ...................................... 2 6 C. Reason ................................................ 2 6 D. Description .............................................. 2 8 E. Compliance .............................................. 3 1 F. Approval ............................................... 4 6 G. Manpower .............................................. 4 7 H. Weight and Balance Changes .................................... 4 9 I. Electrical Load Data ......................................... 5 2 J. References .............................................. 5 2 1. Existing Data: ......................................... 5 2 2. Data supplied with this Service Bulletin: ........................... 5 2 3. Installation Drawings Used in the Preparation of this Service Bulletin: ........... 5 3 K. Publications Affected ........................................ 5 3 L. Interchangeability and Intermixability of Parts ........................... 5 3 2. MATERIAL INFORMATION ........................................ 5 5 A. Material - Price and Availability ................................... 5 5 B. Industry Support Information .................................... 5 6 C. Parts Necessary For Each Airplane ................................. 5 6 1. Kits/Parts: ........................................... 5 6 2. Parts and Materials Supplied by the Operator: ........................ 7 4 3. Parts Modified and Reidentified: ............................... 7 5 4. Parts Removed and Not Replaced: .............................. 7 5 D. Parts Necessary to Change Spares ................................. 7 5 E. Special Tooling - Price and Availability ............................... 7 5 F. Special Tooling Necessary to do this Service Bulletin ....................... 7 6 3. ACCOMPLISHMENT INSTRUCTIONS .................................. 7 7 A. GENERAL INFORMATION ..................................... 7 7 B. WORK INSTRUCTIONS ....................................... 7 8 FIGURE 1: ACCESS ............................................ 9 6 FIGURE 2: INSPECTION ......................................... 1 0 0 FIGURE 3: SUPPORT FRAME MODIFICATION ............................. 1 0 5 FIGURE 4: DELETED ........................................... 1 1 4 FIGURE 5: DELETED ........................................... 1 1 5 FIGURE 6: AFT INNER CHORD REPAIR OR INTERIM-MODIFICATION - PARTS AND FASTENER REMOVAL ........................................... 1 1 6 FIGURE 7: UPPER FORWARD INNER CHORD AND FRAME SUPPORT FITTING - INSPECTION . 121 FIGURE 8: UPPER FORWARD INNER CHORD AND FRAME SUPPORT FITTING - FASTENER INSTALLATION ........................................ 1 2 5 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 3 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 4 FIGURE 9: POST-MODIFICATION INSPECTION PART 1 - SUPPORT FRAME AND ACCESS CUT-OUT DETAILED INSPECTION ................................... 1 3 0 FIGURE 10: POST-MODIFICATION INSPECTION PART 1 - LOWER FLOOR SUPPORT CHORD SURFACE HFEC INSPECTION ..................................... 1 3 2 FIGURE 11: POST-MODIFICATION INSPECTION PART 1 - OUTER CHORD LFEC INSPECTION . 137 FIGURE 12: POST-MODIFICATION INSPECTION PART 1 - OUTER CHORD SURFACE AND OPEN HOLE HFEC INSPECTION ..................................... 1 3 9 FIGURE 13: POST-MODIFICATION INSPECTION PART 1 - SUPPORT FRAME OUTER CHORD AND FRAME SUPPORT FITTING ULTRASONIC (UT) INSPECTION .............. 1 4 2 FIGURE 14: POST-MODIFICATION INSPECTION PART 2 - HINGE SUPPORT OPEN HOLE HFEC INSPECTION ......................................... 1 4 4 FIGURE 15: POST-MODIFICATION INSPECTION PART 3 - SUPPORT FRAME INSPECTIONS . . 151 FIGURE 16: POST-MODIFICATION INSPECTION PART 3 - SUPPORT FRAME INSPECTIONS . . 155 FIGURE 17: POST-MODIFICATION INSPECTION PART 3 - SUPPORT FRAME INSPECTIONS . . 157 FIGURE 18: POST-MODIFICATION INSPECTION PART 3 - SUPPORT FRAME INSPECTIONS . . 159 FIGURE 19: AFT INNER CHORD - INSPECTION FOR UPPER AND LOWER CORNER REPAIRS . 162 FIGURE 20: LEFT SIDE UPPER CORNER WEB CRACK REPAIR (CONCURRENT WITH MODIFICATION) [Group 1, 4, Configuration 1] ................................. 1 6 6 FIGURE 21: RIGHT SIDE UPPER CORNER WEB CRACK REPAIR (CONCURRENT WITH MODIFICATION) [Group 1, 4, Configuration 1] ................................. 1 7 0 FIGURE 22: LEFT SIDE UPPER CORNER WEB CRACK REPAIR (CONCURRENT WITH MODIFICATION) [Group 2, Configuration 1, 3; Group 3, Configuration 1, 3; Group 5] ............ 1 7 4 FIGURE 23: RIGHT SIDE UPPER CORNER WEB CRACK REPAIR (CONCURRENT WITH MODIFICATION) [Group 2, Configuration 1, 3; Group 3, Configuration 1, 3; Group 5] ............ 1 7 7 FIGURE 24: LEFT SIDE LOWER CORNER WEB CRACK REPAIR (CONCURRENT WITH MODIFICATION) [Group 1, Configuration 1-2; Group 2, Configuration 1-4; Group 3, Configuration 1-4; Group 4, Configuration 1-2] ....................................... 1 8 0 FIGURE 25: EXISTING LEFT SIDE UPPER CORNER WEB REPAIR (REPAIRED IN ACCORDANCE WITH SERVICE BULLETIN 747-53A2427) [Group 1, 4, Configuration 2] ............. 1 8 4 FIGURE 26: EXISTING RIGHT SIDE UPPER CORNER WEB REPAIR (REPAIRED IN ACCORDANCE WITH SERVICE BULLETIN 747-53A2427) [Group 1, 4, Configuration 2] ............. 1 8 8 FIGURE 27: EXISTING LEFT SIDE UPPER CORNER WEB REPAIR (REPAIRED IN ACCORDANCE WITH SERVICE BULLETIN 747-53A2427) [Group 2, Configuration 2, 4; Group 3, Configuration 2, 4] ................................................. 1 9 2 FIGURE 28: EXISTING RIGHT SIDE UPPER CORNER WEB REPAIR (REPAIRED IN ACCORDANCE WITH SERVICE BULLETIN 747-53A2427) [Group 2, Configuration 2, 4; Group 3, Configuration 2, 4] ................................................. 1 9 6 FIGURE 29: POST-MODIFICATION INSPECTION PART 4 - LEFT SIDE UPPER CORNER WEB POST-REPAIR INSPECTIONS ............................... 2 0 0 FIGURE 30: POST-MODIFICATION INSPECTION PART 4 - RIGHT SIDE UPPER CORNER WEB POST-REPAIR INSPECTIONS ............................... 2 0 5 FIGURE 31: POST-MODIFICATION INSPECTION PART 4 - LEFT SIDE LOWER CORNER WEB POST-REPAIR INSPECTIONS ............................... 2 1 0 FIGURE 32: LEFT SIDE UPPER CORNER WEB CRACK INSPECTION AND REPAIR (POST-MODIFIED AIRPLANES) [Group 1, 4, Configuration 3] ......................... 2 1 3 FIGURE 33: RIGHT SIDE UPPER CORNER WEB CRACK INSPECTION AND REPAIR (POST-MODIFIED AIRPLANES) [Group 1, 4, Configuration 3] ......................... 2 1 7 FIGURE 34: LEFT SIDE UPPER CORNER WEB CRACK INSPECTION AND REPAIR (POST-MODIFIED AIRPLANES) [Group 2-3, Configuration 5; Group 5] .................... 2 2 1 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 4 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 5 FIGURE 35: RIGHT SIDE UPPER CORNER WEB CRACK INSPECTION AND REPAIR (POST-MODIFIED AIRPLANES) [Group 2-3, Configuration 5; Group 5] .................... 2 2 5 FIGURE 36: LEFT SIDE LOWER CORNER WEB CRACK INSPECTION AND REPAIR (POST-MODIFIED AIRPLANES) [Group 1, Configuration 3; Group 2-3, Configuration 5; Group 4, Configuration 3; Group 5] ............................................ 2 2 9 FIGURE 37: POST-MODIFICATION INSPECTION PART 1 - LEFT SIDE UPPER CORNER WEB . . 234 FIGURE 38: POST-MODIFICATION INSPECTION PART 1 - RIGHT SIDE UPPER CORNER WEB . 237 FIGURE 39: POST-MODIFICATION INSPECTION PART 1 - LEFT SIDE LOWER CORNER WEB . . 240 Appendix A: SERVICE BULLETIN REVISION 1 REFERENCE CHANGE INFORMATION ....... 2 4 2 APPENDIX B: SERVICE BULLETIN REVISION 2 REFERENCE CHANGE INFORMATION ....... 2 4 7 APPENDIX C: OPERATOR SUPPLIED MATERIALS ............................ 2 4 8 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 5 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 6 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 6 of 250 BOEING SERVICE BULLETIN 747-53A2473 BLANK PAGE ### Page 7 Commercial Airplanes 747 Service Bulletin Revision Transmittal SheetNumber: 747-53A2473Original Issue: March 24, 2005 Revision 4: December 01, 2011 ATA System: 5313 SUBJECT: FUSELAGE - Section 48 - Body Station 2598 Bulkhead - Horizontal Stabilizer Hinge Support Frame Cracking - Modification and Repair This revision includes all pages of the service bulletin. COMPLIANCE INFORMATION RELATED TO THIS REVISION More work is necessary on airplane(s) changed in accordance with Revision 3 of this service bulletin, but only if a post-modification inspection was accomplished in accordance with paragraph 3.B.8, Part 1, step a.6. of Revision 3 of this service bulletin and an additional condition specified in this revision applies. If both the above noted conditions apply, a one time surface high-frequency eddy current (HFEC) inspection of the support frame outer chord for cracks is to be accomplished at one fastener location on each side of the bulkhead. Federal Aviation Administration (FAA) Airworthiness Directive AD 2010-14-07 is related to this service bulletin. REASON FOR REVISION This revision is sent to give a revised sheet 7 (DCN B) of drawing 624U0061 which adds one fastener location (each side) to the support frame outer chord crack inspection. The added fastener location was inadvertantly omitted from the drawing sheet provided with the previous release of this service bulletin. The revised sheet 7 of drawing 624U0061 also includes a changed/corrected use of flagnote 2. This revision is also sent to change the group applicability assigned to Figures 10, 12 and 13 and to Table 6 of Paragraph 1.E., Compliance. In the previous release of this service bulletin, these group applicabilities were not complete and therefore, for some groups, more than the data extracted according to the group applicability would be needed to accomplish the work instruction. These sections were changed: 1. Paragraph 1.E., Compliance: Changed group applicability assigned to Table 6 from Group 1, 3 to Group 1-3. Also, added compliance Table 11 for the more work requirement associated with this revision. 2. Paragraph 1.J.2., References, Data supplied with this Service Bulletin: Changed revision level for drawing 624U0061, sheet 7 from DCN A to DCN B. 3. Accomplishment Instruction 3.B.8., Part 1: Added instruction for a one time inspection which is the more work requirement associated with this revision. 4. Figure 10: Changed the group applicability assigned to the figure from Group 1-3 to Group 1-5. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 7 of 250 ### Page 8 5. Figure 12: Added flagnote 19 to identify the more work inspection location and changed the group applicability assigned to the figure from Group 4-5 to Group 1-5. 6. Figure 13: Changed the group applicability assigned to the figure from Group 4-5 to Group 1-5. Vertical lines are put on the left edge of each page, except in Paragraph 1.A., Effectivity, to show the location of important changes. Pages with no vertical lines have no important changes. REVISION HISTORY March 24, 2005Original Issue: February 20, 2007Revision 1: August 28, 2009Revision 2: July 14, 2011Revision 3: December 01, 2011Revision 4: BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 8 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 9 Commercial Airplanes 747 Service Bulletin SummaryNumber: 747-53A2473Original Issue: March 24, 2005 Revision 4: December 01, 2011 ATA System: 5313 SUBJECT: FUSELAGE - Section 48 - Body Station 2598 Bulkhead - Horizontal Stabilizer Hinge Support Frame Cracking - Modification and Repair CONCURRENT REQUIREMENTS None BACKGROUND This service bulletin gives instruction for a modification to the support frame at body station 2598. This modification makes the support frame more resistant to fatigue cracks in the areas that must be inspected to satisfy requirements given in the FAA Airworthiness Directives and Boeing service bulletins identified in the table below. This modification can be done to permanently satisfy requirements related to these Airworthiness Directives and service bulletins as shown below. NoteFAA Airworthiness DirectiveBoeing Service Bulletin (a)2001-15-03, Amendment 39-12337, superseded by 2010-14-07, Amendment 39-16352. 747-53A2427 (a)2001-14-07, Amendment 39-12318, superseded by 2010-14-07, Amendment 39-16352. 747-53A2449 (b)2003-19-08, Amendment 39-13311, superseded by 2010-14-07, Amendment 39-16352. 747-53A2467 (c), (d)2010-14-07, Amendment 39-16352747-53-2473 747-53A2473 (a) All inspection requirements terminated - no more work necessary after the modification. (b) Inspection of the support frame aft inner chord per Boeing service bulletin 747-53A2467 is not necessary after the modification; however, inspection of the upper aft outer chords, and the diagonal brace attachment fittings, flanges, and rods per service bulletin 747- 53A2467 is necessary after the modification. (c) This AD supersedes 2001-15-03, Amendment 39-12337; 2001-14-07, Amendment 39- 12318; 2003-19-08, Amendment 39-13311; and 2006-05-06, Amendment 39-14503 except for the inspection requirements stated in note (b) above. (d) Post-modification inspection is required as given in the requirements of this AD. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 9 of 250 ### Page 10 NOTE: Refer to Appendix A and B for the change information previously described in Revision 1 and Revision 2 of this service bulletin. Since the release of Revision 2 of this service bulletin, several operators have reported finding cracks in the support frame upper and lower corner web at the aft inner chord to upper floor chord joint. Cracks in the upper web have been reported to be between approximately 0.80 inch to 0.55 inch long, and between 0.20 inch to 1.30 inch long in the lower web. Two operators have reported web cracks on airplanes with 8,435 and 8,940 total flight cycles. Other reports have described web cracks found on airplanes with greater than 20,000 total flight cycles. Revision 3 is being sent to add a new high-frequency eddy current (HFEC) inspection for cracks in the support frame left and right side upper corner web, and left side lower corner web at the aft inner chord to upper and lower floor support joint. Instructions and parts for a local web repair is provided for any crack that is found within specified limits during the initial support frame modification inspection or during post-modification inspections. Boeing Service Related Problem (SRP) 747-SRP-53-0343 is related to this service bulletin. ACTION (PRR 85901-103RS) MODIFICATION Two web doublers, new upper and lower hinge back-up fittings, and a new inner chord are to be installed on the aft side of the support frame on each side of the airplane. Lift and hold the horizontal stabilizer using external supports, or an optional special tool that Boeing can supply, while the modification work is done. This is necessary to permit removal of the stabilizer hinge back up structure from the aft side of the support frame. Inspection of specified areas/locations of the support frame with surface high-frequency eddy current (HFEC) and open hole HFEC is to be done before the new parts are installed. Oversize fasteners are to be installed at specified locations where insurance cuts are required to remove material that could contain an undetected crack. This mixture of inspection work, insurance cuts, structural reinforcement and new parts is necessary to terminate the inspection requirements identified above. In addition, a surface HFEC inspection for cracks in the support frame left and right side upper corner web, and left side lower corner web is required before modification work is done. If no cracks are found then repeat HFEC inspections will be necessary during post-modification inspections. If any crack is found within defined web trim out limits, local repairs are provided in this service bulletin that can be done concurrently with the modification work. Any crack that is found to extend outside of defined web trim out limits will require contacting Boeing for repair data. POST-MODIFICATION Do a one-time General Visual Inspection (GVI) of the upper forward inner chord, frame support fitting and splice fitting for the installation of BACB30NX10K*, BACB30NX10K*X (1/64 oversize) or BACB30NX10K*Y (1/32 oversize) fasteners, and if installed do a one-time review of airplane maintenance records to verify that during the initial modification installation an open hole high frequency eddy current (HFEC) inspection was accomplished and holes were zero-timed. If an open hole HFEC inspection was accomplished and holes were zero-timed during the initial modification installation, no further action is required at these fastener locations. If the accomplishment of an open hole HFEC inspection and zero-time of holes can not be verified, additional modification work is necessary. If .247/.250, .263/.266 (1/64 oversize) or 278/.281 (1/32 oversize) inch diameter fasteners are installed, remove fasteners and do an open hole HFEC inspection. If no cracks are found, zero-time holes and install BACB30NX10K* fasteners. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 10 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 11 Do a one-time GVI of the frame web and upper shear deck (floor support) chord aft side for (2) fasteners that were installed as part of an aft inner chord repair removal. If a repair was not installed or if bolts are installed at the (2) fastener locations specified , no further action is required at these fastener locations. If a repair removal was accomplished and 7/32 inch diameter rivets are installed, additional work is required. If a repair removal was accomplished and 3/16 inch diameter rivets are installed, remove rivets and do an open hole HFEC inspection. If no cracks are found, install new bolts. Do a one-time GVI for repair(s) installed on the left and right side aft inner chords. If a repair was not installed, no further action is required for this inspection. If any repair is installed, more work is required. For all airplanes modified in accordance with this service bulletin, post-modification inspections have been added. See Paragraph 1.E., Compliance. In addition, a surface HFEC inspection for cracks in the support frame left and right side upper corner web, and left side lower corner web is required on a modified support frame. If no cracks are found then repeat HFEC inspections will be necessary during post-modification inspections. If any crack is found within defined web trim out limits on a modified support frame, repairs are provided in this service bulletin that can be installed in addition to the existing modification. Any crack that is found to extend outside of defined web trim out limits will require contacting Boeing for repair data. EFFECTIVITY 747-100/-100B/-100B SUD/-200B/-200C/-200F/-300/-400/-400D/-400F/SP/SR airplanes. Refer to Paragraph 1.A.1, Airplanes, for the list of affected airplanes. COMPLIANCE See Service Bulletin Paragraph 1.E. for compliance information. Federal Aviation Administration (FAA) Airworthiness Directive AD 2006-05-06 was superseded by AD 2010-14-07, which is related to this service bulletin. INDUSTRY SUPPORT INFORMATION Boeing warranty remedies are not available for the inspection procedures or the modification and repair given in this service bulletin. MANPOWER Support Frame Modification Elapsed HoursTotal Task HoursAirplanes 104.50305.00All (no web crack re- pair installed) 107.00315.00All (with web crack repair installed) Support Frame Upper Corner Fastener Inspection/Rework Elapsed HoursTotal Task HoursAirplanes 7.7515.50All BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 11 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 12 Support Frame Post-Modification Inspections Elapsed HoursTotal Task HoursAirplanes 87.00200.00All - Part 1, 2, 3 & 4 MATERIAL INFORMATION Boeing Supplied Kits/Parts. Refer to Paragraph 2.A., Material - Price and Availability. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 12 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 13 (OCR) BOEING SERVICE BULLETIN 747-53A2473 STA 2598 STA 2598 UPPER FORWARD OUTER CHORD FRAME SUPPORT AFT INNER CHORD FRAME SUPPORT MODIFICATION DO HFEC INSPECTION (SURFACE AND OPEN HOLE AT SPECIFIED LOCATIONS AND INSTALL TWO WEB DOUBLERS, NEW HORIZONTAL HINGE BACK-UP FITTINGS AND A NEW STABILIZER INNER CHORD ON THE AFT SIDE OF THE UP BULKHEAD ON BOTH SIDES OF THE AIRPLANE. LOWER FORWARD POST-MODIFICATION OUTER CHORD DO DETAILED, LFEC/HFEC AND ULTRASONIC V85165 INSPECTIONS OF A MODIFIED BULKHEAD. Original Issue: March 24, 2005 Revision 4: December 01, 2011 747-53A2473 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 13 of 250 ### Page 14 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 14 of 250 BOEING SERVICE BULLETIN 747-53A2473 BLANK PAGE ### Page 15 Commercial Airplanes 747 Service Bulletin Number: 747-53A2473 Original Issue: March 24, 2005 Revision 4: December 01, 2011 ATA System: 5313 SUBJECT: FUSELAGE - Section 48 - Body Station 2598 Bulkhead - Horizontal Stabilizer Hinge Support Frame Cracking - Modification and Repair 1. PLANNING INFORMATION A. Effectivity 1. Airplanes Refer to Service Bulletin Index Document D6-30300 Part 3 for Airplane Variable Number, Line Number, and Serial Number data. This service bulletin is for the airplanes shown below. An equivalent change is on subsequent production airplanes. Refer to PRR 85428 for data about this change. DESCRIPTIONCONFIGURATIONGROUP 747-100/-100B/-100BSUD/-200B/-200C/-200F/-300/SR airplanes with line numbers 1-695. -1 Line numbers 1-695 and no interim modification or existing upper corner web crack repair(s) installed in accordance with Boeing Service Bulletin 747-53A2427. 1 Line numbers 1-695 and does have an interim modification or existing upper corner web crack repair(s) installed in accordance with Boeing Service Bulletin 747-53A2427. 2 Line numbers 1-695 with a support frame modified in accordance with this service bulletin and no upper or lower corner web crack repair(s) installed. 3 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 15 of 250 ### Page 16 DESCRIPTIONCONFIGURATIONGROUP 747-400/-400D/-400F airplanes with line numbers 696-1307 with no horizontal stabilizer fuel tank. -2 Line numbers 696-1241 and no interim modification or existing upper corner web crack repair(s) installed in accordance with Boeing Service Bulletin 747-53A2427. 1 Line numbers 696-1241 and does have an interim modification or existing upper corner web crack repair(s) installed in accordance with Boeing Service Bulletin 747-53A2427. 2 Line numbers 1242-1307 and no existing upper corner web crack repair(s) installed in accordance with Boeing Service Bulletin 747-53A2427. 3 Line numbers 1242-1307 and does have existing upper corner web crack repair(s) installed in accordance with Boeing Service Bulletin 747-53A2427. 4 Line numbers 696-1307 with a support frame modified in accordance with this service bulletin and no upper or lower corner web crack repair(s) installed. 5 747 airplanes with line numbers 696-1307 with a horizontal stabilizer fuel tank. -3 Line numbers 696-1241 and no interim modification or existing upper corner web crack repair(s) installed in accordance with Boeing Service Bulletin 747-53A2427. 1 Line numbers 696-1241 and does have an interim modification or existing upper corner web crack repair(s) installed in accordance with Boeing Service Bulletin 747-53A2427. 2 Line numbers 1242-1307 and no existing upper corner web crack repair(s) installed in accordance with Boeing Service Bulletin 747-53A2427. 3 Line numbers 1242-1307 and does have existing upper corner web crack repair(s) installed in accordance with Boeing Service Bulletin 747-53A2427. 4 Line numbers 696-1307 with a support frame modified in accordance with this service bulletin and no upper or lower corner web crack repair(s) installed. 5 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 16 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 17 DESCRIPTIONCONFIGURATIONGROUP 747SP airplanes.-4 747SP and no interim modification or existing upper corner web crack repair(s) installed in accordance with Boeing Service Bulletin 747-53A2427. 1 747SP and does have an interim modification or existing upper corner web crack repair(s) installed in accordance with Boeing Service Bulletin 747-53A2427. 2 747SP airplanes with a support frame modified in accordance with this service bulletin and no upper or lower corner web crack repair(s) installed. 3 747-LCF (Large Cargo Freighter) airplanes with line numbers 766, 778, 904 and 932. -5 Airplane Models: 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SP, 747SR GroupVariable Number 1RA001 - RA034 1RA101 - RA115 1RA161 - RA164 1RA201 - RA203 1RA216 - RA217 1RA245 - RA246 1RA251 - RA266 1RA301 - RA318 1RA351 - RA360 1RA369 - RA373 1RA401 - RA418 1RA501 - RA502 1RA521 - RA528 1RA532 - RA548 1RA551 - RA552 1RA559 - RA561 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 17 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 18 GroupVariable Number 1RA581 - RA582 1RA585 1RA601 - RA602 1RA631 - RA635 1RA651 - RA652 1RA671 - RA677 1RA701 - RA702 1RA721 - RA731 1RA741 - RA745 1RA749 - RA750 1RA761 - RA762 1RA781 - RA784 1RA901 - RA916 1RB001 - RB016 1RB041 - RB044 1RB071 - RB075 1RB101 - RB102 1RB411 - RB412 2RB413 2RB421 1RB601 - RB607 1RB681 - RB697 1RB711 1RB721 - RB723 1RB741 - RB748 1RD001 - RD004 1RD021 - RD022 1RD041 - RD059 1RD071 - RD072 1RD081 - RD083 1RD091 - RD092 1RD101 - RD104 1RD121 - RD127 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 18 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 19 GroupVariable Number 1RD131 - RD144 1RD166 - RD167 1RD171 - RD172 1RD181 - RD183 1RD201 - RD204 1RD221 - RD227 1RD231 - RD234 2RD235 1RD241 - RD243 1RD251 - RD262 1RD271 - RD272 1RD291 - RD292 1RD301 - RD302 1RD311 1RD351 - RD358 1RD361 - RD366 1RD381 - RD383 1RD411 - RD414 1RD421 - RD426 1RD431 - RD435 1RD441 - RD442 1RD451 - RD456 1RD461 1RD471 - RD475 1RD513 - RD519 1RD531 - RD533 1RD551 1RD561 1RD571 1RD581 - RD583 1RD591 - RD593 1RD601 - RD607 1RD621 - RD623 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 19 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 20 GroupVariable Number 1RD641 - RD649 1RD651 - RD659 1RD661 1RD671 1RD681 - RD682 1RD691 - RD692 1RD701 - RD702 1RD721 - RD722 1RD741 - RD742 1RD751 - RD755 1RD761 1RD771 - RD775 1RD781 - RD783 1RD791 2RD792 1RE001 4RG001 - RG009 4RG091 4RG095 4RG101 - RG104 4RG121 - RG126 4RG141 - RG142 4RG161 - RG164 4RG171 - RG174 4RG191 - RG193 4RG211 - RG213 4RG221 - RG222 4RH101 - RH102 4RH111 - RH112 4RH121 - RH122 1RJ131 - RJ133 1RJ151 - RJ152 1RJ301 - RJ303 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 20 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 21 GroupVariable Number 1RJ321 2RJ322 1RJ331 - RJ333 2RL401 - RL402 2RL411 - RL419 2RL651 - RL654 2RL751 2RM001 - RM007 3RM010 - RM013 3RM021 - RM024 3RM026 - RM029 3RM036 - RM045 3RM051 - RM052 3RM071 3RM081 - RM084 3RM091 3RM096 - RM097 3RM116 - RM117 2RM126 - RM132 3RM136 - RM147 3RM156 - RM158 3RM166 - RM177 3RM191 - RM192 3RM231 - RM233 3RM241 - RM246 3RM261 - RM264 2RM316 - RM318 3RM331 - RM333 3RM341 3RM351 - RM355 3RM366 - RM367 3RM801 - RM803 2RM811 - RM813 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 21 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 22 GroupVariable Number 2RM851 - RM858 2RM861 - RM862 2RM871 - RM876 2RM881 - RM886 2RM891 - RM899 2RM901 - RM905 2RM911 1RR001 - RR005 1RR021 - RR023 2RR024 - RR025 1RR031 1RR201 - RR205 2RR206 1RR221 - RR226 1RR261 - RR267 1RR301 - RR306 2RR307 - RR309 3RR310 1RR331 - RR332 1RR336 1RR341 - RR345 1RR361 - RR362 1RR421 - RR422 1RR431 - RR432 1RR441 2RR442 2RR451 1RR501 - RR504 1RR521 2RR522 2RR526 1RR531 1RR551 - RR554 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 22 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 23 GroupVariable Number 2RR555 - RR556 1RR561 2RR566 2RR701 2RR721 - RR724 2RR746 - RR748 2RR851 - RR856 2RR861 - RR862 2RR951 - RR952 1RS001 - RS002 1RS201 1RS211 - RS212 1RS221 - RS222 1RS231 - RS241 1RS251 - RS259 2RS263 1RS265 - RS268 1RS271 - RS276 1RS291 - RS292 1RS301 - RS305 2RS306 1RS311 - RS320 2RS331 - RS333 1RS341 - RS342 1RS699 1RS701 - RS703 1RS711 - RS713 1RS721 - RS722 2RS731 - RS732 1RS741 - RS743 1RS751 - RS752 1RS761 2RS762 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 23 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 24 GroupVariable Number 1RS771 2RS781 - RS782 2RS786 3RT001 - RT014 3RT021 - RT022 2RT031 - RT035 2RT041 - RT042 3RT043 - RT047 3RT061 3RT071 - RT073 2RT074 - RT075 3RT101 - RT103 3RT121 3RT131 - RT137 3RT151 - RT152 3RT161 - RT168 3RT401 - RT412 3RT431 - RT447 3RT451 - RT455 2RT456 3RT457 - RT469 3RT471 - RT499 2RT501 3RT502 - RT507 2RT508 - RT510 3RT511 - RT512 2RT513 3RT514 - RT519 2RT520 3RT521 - RT530 2RT531 - RT535 3RT551 - RT568 3RT571 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 24 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 25 GroupVariable Number 2RT572 - RT576 3RT577 - RT591 3RT601 - RT630 5RT631 - RT632 3RT633 - RT650 2RT651 - RT657 3RT671 - RT673 2RT681 - RT682 3RT691 - RT699 3RT701 - RT704 2RT711 - RT717 3RT741 - RT742 5RT743 3RT744 - RT755 2RT756 - RT757 3RT776 - RT777 2RT781 - RT782 3RT783 - RT784 3RT801 - RT803 3RT811 - RT814 3RT831 - RT837 3RT861 - RT864 5RT876 2RT877 - RT880 3RT931 - RT932 3RT945 - RT949 3RT951 - RT955 2RT966 - RT967 2RU001 - RU006 3RU016 - RU017 3RU031 - RU032 3RU051 - RU052 3RU059 - RU062 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 25 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 26 GroupVariable Number 3RU081 - RU083 3RU101 - RU102 3RU121 2RU122 - RU125 3RU126 - RU132 2RU801 - RU809 2RU831 - RU841 2. Spares Affected None. B. Concurrent Requirements None. C. Reason The modification specified in this service bulletin will make the support frame at body station 2598 more resistant to fatigue cracks in the areas that must be inspected to satisfy requirements in the FAA Airworthiness Directives and Boeing service bulletins identified in the table below. This modification can be done to permanently satisfy requirements related to these Airworthiness Directives and service bulletins as shown below. NoteFAA Airworthiness DirectiveBoeing Service Bulletin (a)2001-15-03, Amendment 39-12337, superseded by 2010-14-07, Amendment 39-16352. 747-53A2427 (a)2001-14-07, Amendment 39-12318, superseded by 2010-14-07, Amendment 39-16352. 747-53A2449 (b)2003-19-08, Amendment 39-13311, superseded by 2010-14-07, Amendment 39-16352. 747-53A2467 (c), (d)2010-14-07, Amendment 39-16352747-53-2473 747-53A2473 (a) All inspection requirements terminated - no more work necessary after the modification. (b) Inspection of the support frame aft inner chord per Boeing service bulletin 747-53A2467 is not necessary after the modification; however, inspection of the upper aft outer chords, and the diagonal brace attachment fittings, flanges, and rods per service bulletin 747- 53A2467 is necessary after the modification. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 26 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 27 NoteFAA Airworthiness DirectiveBoeing Service Bulletin (c) This AD supersedes 2001-15-03, Amendment 39-12337; 2001-14-07, Amendment 39- 12318; 2003-19-08, Amendment 39-13311; and 2006-05-06, Amendment 39-14503 except for the inspection requirements stated in note (b) above. (d) Post-modification inspection is required as given in the requirements of this AD. NOTE: Refer to Appendix A and B for the change information previously described in Revision 1 and Revision 2 of this service bulletin. Since the release of Revision 1 of this service bulletin, an operator has reported that a crack was found in the support frame upper forward inner chord 2,521 flight cycles after modification work was accomplished in accordance with Revision 1 of this service bulletin. Boeing investigation has revealed missing fastener symbols on the original issue and Revision A of service bulletin retrofit drawing sheet 3. The missing symbols may result in the omission of an open hole high frequency eddy current (HFEC) inspection and the installation of incorrect diameter fasteners at (20) total fastener locations, left and right side, common to the upper forward inner chord, frame support fitting and splice fitting. If the holes common to the forward upper inner chord, frame support fitting and splice fitting are not HFEC inspected for a crack free condition and then oversized in accordance with the intended service bulletin instructions, an active crack tip may not be detected and continue to propagate. Continued cracking of the support frame inner chord, frame support fitting or splice fitting can lead to large cracks that may result in the inability of the structure to carry horizontal stabilizer flight loads. Revision 2 is being sent to do a one-time General Visual Inspection (GVI) of the upper forward inner chord, frame support fitting and splice fitting is required to determine if the correct modification fasteners are installed and if applicable, a one-time airplane maintenance record review is required to verify fastener holes were open hole high frequency eddy current (HFEC) inspected and zero-timed in accordance with modification instructions. If the accomplishment of an open hole HFEC inspection and zero-time of holes can not be verified, or if incorrect fasteners are found installed, additional modification work is necessary. If an airplane was modified in accordance with Revision 1 of this service bulletin, a one-time GVI is required to determine if rivets were installed as part of an aft inner chord repair removal. If a repair was not installed or if bolts are installed, no further action is required at these fastener locations. If rivets are installed, additional work is required. If an airplane was modified in accordance with the original issue of this service bulletin, a one-time GVI is required to determine if an aft inner chord upper and/or lower corner repair was installed. If a repair was not installed, no further action is required for this inspection. If any repair is installed, more work is required. Boeing has developed the inspection requirements necessary to be accomplished on a modified support frame, and those inspections are included in this revision. Boeing has validated the modification work in accordance with this service bulletin. Included in this revision are post-validation changes that clarify and revise notes, add more open hole HFEC inspections and add more notes to accomplish the modification. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 27 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 28 Since the release of Revision 2 of this service bulletin, several operators have reported finding cracks in the support frame upper and lower corner web at the aft inner chord to floor chord joint. Cracks in the upper web have been reported to be between approximately 0.80 inch to 0.55 inch long, and between 0.20 inch to 1.30 inch long in the lower web. Two operators have reported web cracks on airplanes with 8,435 and 8,940 total flight cycles. Other reports have described web cracks found on airplanes with greater than 20,000 total flight cycles. Revision 3 is being sent to add a new high-frequency eddy current (HFEC) inspection for cracks in the support frame left and right side upper corner web, and left side lower corner web at the aft inner chord to upper and lower floor support joint. Instructions and parts for a local web repair is provided for any crack that is found within specified limits during the initial support frame modification inspection or during post-modification inspections. Revision 4 is sent to to give a revised sheet 7 (DCN B) of drawing 624U0061 to add one fastener location (each side) to the outer chord crack inspection. The added fastener location was inadvertantly omitted from the drawing sheet provided with the previous release of this service bulletin. Also, Revision 4 is sent to change the group applicability assigned to Figures 10, 12 and 13 and Table 6 of Paragraph 1.E., Compliance. In the previous release of this service bulletin, these group applicabilities were not complete. Boeing Service Related Problem (SRP) 747-SRP-53-0343 is related to this service bulletin. D. Description The support frame modification includes two web doublers, new upper and lower hinge back-up fittings, and a new inner chord - all to be installed on the aft side of the support frame on each side of the airplane. Inspection of specified areas/locations with surface HFEC and open hole HFEC is to be done before the new parts are installed. Oversize fasteners are to be installed at specified locations where insurance cuts are required to remove material that could contain an undetected crack. The instruction given in this service bulletin refers to drawing sheets that show which parts are to be removed, where open hole inspections are to be done, and how the new parts are to be installed. Before parts are removed from the support frame, the load from the weight of the horizontal stabilizer must be removed from the hinge fittings attached to the support frame. To do this the upper and lower diagonal braces are to be removed from each side of the support frame and a special tool supplied by Boeing is to be installed between the upper/lower diagonal brace attachment fittings. This tool is used to lift and hold the horizontal stabilizer to remove the load from the hinges attached to the support frame. Revision 1 - More work is necessary on airplanes changed as shown in the original issue of this service bulletin. It is necessary to remove an existing aft inner chord that has been repaired prior to the modification given in this service bulletin. If the modification given in the original issue of this service bulletin is installed with a repaired aft inner chord in place, the repaired aft inner chord must be replaced with a new aft inner chord and the modification must be reinstalled. Contact Boeing for the instructions. NOTE: A zero-timed hole is the removal of small cracks and fatigue damaged material from an existing hole by performing an open-hole high frequency eddy current (HFEC) inspection and if crack free, oversizing the hole 1/16 inch diameter. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 28 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 29 Revision 2 - More work is required if an airplane was modified in accordance with the original issue or Revision 1 of this service bulletin. A one-time General Visual Inspection (GVI) of the upper forward inner chord, frame support fitting and splice fitting is required to determine if the correct modification fasteners are installed and if applicable, a one-time airplane maintenance record review is required to verify fastener holes were open hole high frequency eddy current (HFEC) inspected and zero-timed in accordance with modification instructions. If the accomplishment of an open hole HFEC inspection and zero-time of holes can not be verified, or if incorrect fasteners are found installed, additional modification work is necessary. More work is required if an airplane was modified in accordance with Revision 1 of this service bulletin. A one-time GVI is required to determine if rivets were installed as part of an aft inner chord repair removal. If a repair was not installed or if bolts are installed, no further action is required at these fastener locations. If rivets are installed, additional work is required. More work is required if an airplane was modified in accordance with the original issue of this service bulletin. A one-time GVI is required to determine if an aft inner chord upper and/or lower corner repair was installed. If a repair was not installed, no further action is required for this inspection. If any repair is installed, more work is required. Boeing has developed the inspection requirements necessary to be accomplished on a modified support frame, and those inspections are included in this revision. Boeing has validated the modification work in accordance with this service bulletin. Included in this revision are post-validation changes that clarify and revise notes, add more open hole HFEC inspections and add more notes to accomplish the modification. Do a one-time General Visual Inspection (GVI) of the upper forward inner chord, frame support fitting and splice fitting for the installation of BACB30NX10K*, BACB30NX10K*X (1/64 oversize) or BACB30NX10K*Y (1/32 oversize) fasteners, and if installed do a one-time review of airplane maintenance records to verify that during the initial modification installation an open hole high frequency eddy current (HFEC) inspection was accomplished and holes were zero-timed. If an open hole HFEC inspection was accomplished and holes were zero-timed during the initial modification installation, no further action is required at these fastener locations. If the accomplishment of an open hole HFEC inspection and zero-time of holes can not be verified, additional modification work is necessary. If .247/.250, .263/.266 (1/64 oversize) or 278/.281 (1/32 oversize) inch diameter fasteners are installed, remove fasteners and do an open hole HFEC inspection. If no cracks are found, zero-time holes and install BACB30NX10K* fasteners. Do a one-time GVI of the frame web and upper shear deck (floor support) chord aft side for (2) fasteners that were installed as part of an aft inner chord repair removal. If a repair was not installed or if bolts are installed at the (2) fastener locations specified , no further action is required at these fastener locations. If a repair removal was accomplished and 7/32 inch diameter rivets are installed, additional work is required. If a repair removal was accomplished and 3/16 inch diameter rivets are installed, remove rivets and do an open hole HFEC inspection. If no cracks are found, install new bolts. Do a one-time GVI for repair(s) installed on the left and right side aft inner chords. If a repair was not installed, no further action is required for this inspection. If any repair is installed, more work is required. For all airplanes modified in accordance with this service bulletin, post-modification inspections have been added. See Paragraph 1.E., Compliance. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 29 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 30 Revision 3 - A surface HFEC inspection for cracks in the support frame left and right side upper corner web, and left side lower corner web is required before modification work is done. If no cracks are found then repeat HFEC inspections will be necessary during post-modification inspections. If any crack is found within defined web trim out limits, local repairs are provided in this service bulletin that can be done concurrently with the modification work. Any crack that is found to extend outside of defined web trim out limits will require contacting Boeing for repair data More work is required if an airplane was modified in accordance with the original issue, Revision 2 or Revision 3 of this service bulletin. A surface HFEC inspection for cracks in the support frame left and right side upper corner web, and left side lower corner web is required on a modified support frame. If no cracks are found then repeat HFEC inspections will be necessary during post-modification inspections. If any crack is found within defined web trim out limits on a modified support frame, repairs are provided in this service bulletin that can be installed in addition to the existing modification. Any crack that is found to extend outside of defined web trim out limits will require contacting Boeing for repair data. Revision 4: More work is necessary on airplane(s) changed in accordance with Revision 3 of this service bulletin, but only if a post-modification inspection was accomplished in accordance with Accomplishment Instruction Paragraph 3.B.8., Part 1, step a(6) of Revision 3 of this service bulletin. In such a case, a surface HFEC inspection for cracks in the support frame outer chord is to be accomplished at one fastener location each side. Inspection at this location was inadvertantly omitted from the instruction given in Revision 3 of this service bulletin. The work in this service bulletin is done in the maintenance zone(s) given below. Group 1: Affected Maintenance Zones ZoneModel 315, 316747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747SR Group 2: Affected Maintenance Zones ZoneModel 315, 316747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F Group 3: Affected Maintenance Zones ZoneModel 315, 316747-200F, 747-400 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 30 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 31 Group 4: Affected Maintenance Zones ZoneModel 315, 316747SP Group 5: Affected Maintenance Zones ZoneModel 315, 316747-400 E. Compliance Federal Aviation Administration (FAA) Airworthiness Directives 2004-07-22 R1 is related to this service bulletin. Federal Aviation Administration (FAA) Airworthiness Directive AD 2006-05-06 was superseded by AD 2010-14-07, which is related to this service bulletin. Table 1: Compliance Table Index Support Frame Modifi- cation Installed In Ac- cordance With Origi- nal Issue Support Frame Modifi- cation Installed In Ac- cordance With Revi- sion 1 Support Frame Modifi- cation Installed In Ac- cordance With Revi- sion 2 No Support Frame Modification Installed Airplane See Tables 5, 6, 7, 10See Tables 4, 5, 6, 7See Tables 6, 7See Tables 2, 6, 7Group 1-3 See Tables 5, 8, 9, 10See Tables 4, 5, 8, 9See Tables 8, 9See Tables 3, 8, 9Group 4-5 In addition to the applicable tables identified above, Table 11 is applicable if the two conditions given in paragraph 3.B.8, Part 1 for the more work requirement associated with Revision 4 apply. The action given in Table 11 is the more work requirement associated with Revision 4 of this service bulletin. Group 1-3: Table 2: Station 2598 - Support Frame Modification Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Before 20,000 total flight cycles or within 18 months after the effective date of AD 2010- 14-07, whichever occurs later. Do the support frame inspections and modification in accor- dance with Revision 3 of this service bul- letin Accomplishment Instructions 3.B.1 through 3.B.6. All airplanes with no support frame modifi- cation installed. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 31 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 32 Group 1-3: Table 2: Station 2598 - Support Frame Modification Repeat Interval (Not to Exceed) Compliance TimeActionCondition -In accordance with Table 6 and 7.Do post-modification inspections. Proceed to Table 6 and 7. Support frame modifi- cation installed and no upper or lower corner web crack re- pair(s) installed, or web crack repair(s) installed. Group 4-5: Table 3: Station 2598 - Support Frame Modification (LCF/SP) Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Before 12,000 total flight cycles or within 18 months after the effec- tive date of AD 2010-14-07, whichever occurs later. Do the support frame in- spections, repairs if nec- essary and modification in accordance with Revi- sion 3 of this service bul- letin Accomplishment In- structions 3.B.1 through 3.B.6. All airplanes with no sup- port frame modification in- stalled. -In accordance with Table 8 and 9.Do post-modification in- spections. Proceed to Table 8 and 9. Support frame modification installed and no upper or lower corner web crack re- pair(s) installed, or web crack repair(s) installed. Group 1-5: Table 4: Support Frame Upper Corner Fastener Inspection Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Within 1,500 flight cycles af- ter modification installation or within 1,000 flight cycles after the date on Revision 2 of this service bulletin, whichever occurs later. Station 2598, LBL and RBL 35, WL 320, in accordance with Ac- complishment Instructions 3.B.7.c., do a one-time General Visual Inspection (GVI) of the frame web and upper shear deck (floor support) chord aft side for (2) fasteners that were installed as part of an aft inner chord repair removal. All airplanes with a sup- port frame modification installed in accordance with Revision 1 of this service bulletin. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 32 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 33 Group 1-5: Table 4: Support Frame Upper Corner Fastener Inspection Repeat Interval (Not to Exceed) Compliance TimeActionCondition -In accordance with Table 5.Proceed to Table 5.Condition 1: A repair was not installed or bolts are installed. -Before further flight.Contact Boeing for rework data and do the rework. Condition 2: A repair re- moval was accomplished and 7/32 inch diameter, or greater, rivets are in- stalled. See note (a). -Before further flight.Remove rivets and do an open hole high frequency eddy current (HFEC) inspection for cracks in the frame web and shear deck (floor support) chord in accor- dance with Accomplishment In- structions 3.B.7.c.(3).(a). Condition 3: A repair re- moval was accomplished and 3/16 inch diameter rivets are installed. -Before further flight.Do a web crack inspection/repair (post-modified airplanes) in accor- dance with this service bulletin Accomplishment Instructions 3.B.12 as applicable Any cracks found during Condition 3 inspection. Or Contact Boeing for repair data and do the repair. See note (a). -Before further flight.Install new bolts in accordance with Accomplishment Instructions 3.B.7.c.(3).(a).2). No cracks found during Condition 3 inspection. See note (a). (a) After rework or repairs are complete, proceed to Table 5. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 33 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 34 Group 1-5: Table 5: Forward Upper Inner Chord, Frame Support Fitting and Upper Splice Fitting Inspection Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Within 1,500 flight cycles after modification installation or within 1,000 flight cycles after the date on Revision 2 of this service bulletin, whichever oc- curs later. Station 2598, LBL and RBL 38, WL 315 - 323, do a one time General Visual Inspection (GVI) of the upper forward inner chord, frame support fitting and splice fitting for the installation of BACB30NX10K( ), BACB30NX10K( )X (1/64 over- size) or BACB30NX10K( )Y (1/32 oversize) fasteners in accordance with Accomplishment Instructions 3.B.7.d. All airplanes with a support frame modifica- tion installed in accor- dance with the original issue date or Revision 1 of this service bul- letin. In accordance with Accomplish- ment Instructions 3.B.7.d.(1), re- view airplane maintenance records to verify that during the initial modification installation an open hole high frequency eddy current (HFEC) inspection was accomplished and holes were zero-timed. Condition 1: BACB30NX10K( ), BACB30NX10K( )X or BACB30NX10K( )Y fasteners are installed. -In accordance with Tables 6 and 7 or 8 and 9 as applicable. Do post-modification inspections. Proceed to Tables 6 and 7 or 8 and 9 as applicable. BACB30NX10K( ), BACB30NX10K( )X or BACB30NX10K( )Y fasteners are installed, and an open hole HFEC inspection was accomplished and holes were zero-timed during the initial modifi- cation installation. -Before further flight.Condition 1, Option 1: Do a one- time surface HFEC inspection around existing fasteners for cracks in the upper forward inner chord, frame support fitting and splice fitting in accordance with Accomplishment Instructions 3.B.7.d.(1).(b). BACB30NX10K( ), BACB30NX10K( )X or BACB30NX10K( )Y fasteners are installed and an open hole HFEC inspection and zero-timing of holes can not be verified. See note (a). Condition 1, Option 2: Contact Boeing for modification rework data, and do the rework. See note (a). BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 34 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 35 Group 1-5: Table 5: Forward Upper Inner Chord, Frame Support Fitting and Upper Splice Fitting Inspection Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Before further flight.Contact Boeing for repair and modification rework data, and do the repair and rework. Any cracks found dur- ing Condition 1, Option 1 inspection. See note (a). -Within 1,500 flight cycles after the one-time surface HFEC inspection. Contact Boeing for modification rework data, and do the rework. See note (a). No cracks found during Condition 1, Option 1 inspection. -Before further flight.Condition 2, Option 1: Remove existing fasteners and do an open hole HFEC inspection for cracks in the upper forward inner chord, frame support fitting and splice fitting in accordance with Accom- plishment Instructions 3.B.7.d.(2).(a). Condition 2: If any .247/.250, .263/.266 (1/64 oversize) or .278/.281 (1/32 over- size) inch diameter fas- teners are installed. Condition 2, Option 2: Do a one- time surface HFEC inspection around existing fasteners for cracks in the upper forward inner chord, frame support fitting and splice fitting in accordance with Accomplishment Instructions 3.B.7.d.(2).(b). -Before further flight.Contact Boeing for repair data, and do the repair. Any cracks found dur- ing Condition 2, Option 1 or 2 inspection. See note (a). -Before further flight.Zero-time holes and install BACB30NX10K( ) fasteners in accordance with Accomplishment Instructions 3.B.7.d.(2).(a).2. No cracks found during Condition 2, Option 1 open hole HFEC inspec- tion. See note (a). -Within 1,500 flight cycles after the one-time surface HFEC inspection. Remove existing fasteners and do an open hole HFEC inspection for cracks in the upper forward inner chord, frame support fitting and splice fitting in accordance with Accomplishment Instructions 3.B.7.d.(2).(b).2. No cracks found during Condition 2, Option 2 surface HFEC inspec- tion. See note (a). -Before further flight.Contact Boeing for repair data, and do the repair. Any cracks found dur- ing Condition 2, Option 2 open hole HFEC in- spection. See note (a). BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 35 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 36 Group 1-5: Table 5: Forward Upper Inner Chord, Frame Support Fitting and Upper Splice Fitting Inspection Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Before further flight.Zero-time holes and install BACB30NX10K( ) fasteners in accordance with Accomplishment Instructions 3.B.7.d.(2).(b).2.b. No cracks found during Condition 2, Option 2 open hole HFEC inspec- tion. See note (a). (a) After rework or repairs are complete, support frame post-modification inspections are required. Group 1, Group 2 and Group 3 airplanes proceed in accordance with Table 6 and 7. Group 4 and Group 5 airplanes proceed in accordance with Table 8 and 9. Group 1-3: Table 6: Support Frame Post-Modification Inspections - Part 1 Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Within 3,000 flight cycles after modification installation in accordance with Accomplish- ment Instructions 3.B.1 through 3.B.6, or within 1,500 flight cycles after the date on Revision 2 of this service bulletin, whichever occurs later. Do Support Frame Post-Modification In- spection in accor- dance with Accom- plishment Instruc- tions 3.B.8., Part 1, a.(3). All airplanes. -Before 20,000 total flight cycles, or within 3,000 flight cycles after modification instal- lation in accordance with Accomplishment Instructions 3.B.1 through 3.B.6, or within 1,500 flight cycles after the date on Revision 2 of this service bulletin, whichever occurs later. Do Support Frame Post-Modification In- spections in accor- dance with Accom- plishment Instruc- tions 3.B.8., Part 1, a.(4), (5), (6) and (7). -Within 6,000 flight cycles after modification installation in accordance with Accomplish- ment Instructions 3.B.1 through 3.B.6, or within 1,500 flight cycles after the date on Revision 3 of this service bulletin, whichever occurs later. Do Support Frame Post-Modification In- spections in accor- dance with Accom- plishment Instruc- tions 3.B.8., Part 1, a.(8), (9) and (10). 1,500 flight cyclesWithin 1,500 flight cycles after the last in- spection. Do Support Frame Post-Modification In- spection in accor- dance with Accom- plishment Instruction 3.B.8., Part 1, a.(4). No cracks found dur- ing 3.B.8., Part 1, a.(4) inspection. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 36 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 37 Group 1-3: Table 6: Support Frame Post-Modification Inspections - Part 1 Repeat Interval (Not to Exceed) Compliance TimeActionCondition 3,000 flight cyclesWithin 3,000 flight cycles after the last in- spection. Do Support Frame Post-Modification In- spection in accor- dance with Accom- plishment Instruction 3.B.8., Part 1, a.(3) and (7). No cracks found dur- ing 3.B.8., Part 1, a.(3) or (7) inspec- tion. See note (a). 1,500 flight cyclesWithin 1,500 flight cycles after the last LFEC inspection. At locations where a low frequency eddy current (LFEC) in- spection was accom- plished, do Support Frame Post-Modifica- tion LFEC inspec- tions in accordance with Accomplishment Instruction 3.B.8., Part 1, a.(5). No cracks found dur- ing 3.B.8., Part 1, a.(5) inspection. See note (b). 6,000 flight cyclesWithin 6,000 flight cycles after the last open hole HFEC inspection. At specific locations where an alternate open hole high fre- quency eddy current (HFEC) inspection was accomplished, do Support Frame Post-Modification open hole HFEC in- spections in accor- dance with Accom- plishment Instruction 3.B.8., Part 1, a.(5). See note (b). BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 37 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 38 Group 1-3: Table 6: Support Frame Post-Modification Inspections - Part 1 Repeat Interval (Not to Exceed) Compliance TimeActionCondition 3,000 flight cyclesWithin 3,000 flight cycles after the last in- spection. Repeat post-modifica- tion inspection in ac- cordance with Accom- plishment Instruction 3.B.8., Part 1, a.(6). No cracks found dur- ing 3.B.8., Part 1, a.(6) inspection. See note (c). 6,000 flight cyclesWithin 6,000 flight cycles after the last open hole HFEC inspection. At specific locations where an alternate open hole high fre- quency eddy current (HFEC) inspection was accomplished in accordance with Ac- complishment Instruc- tion 3.B.8., Part 1, a.(5), repeat post- modification inspec- tion in accordance with Accomplishment Instruction 3.B.8., Part 1, a.(6). See note (c). -Before further flight.Contact Boeing for repair data, and do the repair. Any cracks found during 3.B.8., Part 1, a.(3), (4), (5), (6) or (7) inspection. 3,000 flight cyclesWithin 3,000 flight cycles after the last in- spection. Do Support Frame Post-Modification In- spections in accor- dance with Accom- plishment Instruc- tions 3.B.8., Part 1, a.(8), (9) and (10). No cracks found dur- ing 3.B.8., Part 1, a.(8), (9) or (10) in- spection. -Before further flight.Remove modification parts and do a sur- face high frequency eddy current (HFEC) inspection to deter- mine if total crack length is within de- fined trim out limits in accordance with Ac- complishment Instruc- tions 3.B.12. Any cracks found during post-modifica- tion 3.B.8., Part 1, a.(8), (9) or (10) in- spection. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 38 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 39 Group 1-3: Table 6: Support Frame Post-Modification Inspections - Part 1 Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Before further flight.Contact Boeing for repair data, and do the repair. If total crack length extends outside the defined trim out lim- its. -Before further flight.Do an upper or lower corner post-modifica- tion web crack repair as applicable in ac- cordance with Accom- plishment Instruc- tions 3.B.12. If total crack length is within the defined trim out limits. 3,000 flight cyclesWithin 6,000 flight cycles after repair instal- lation. Do Support Frame Post-Repair Inspec- tion in accordance with Accomplishment Instructions 3.B.8., Part 4, a., b., or c. as applicable. Upper or lower cor- ner post-modification web crack repair in- stalled. (a) The post-modification inspection in Accomplishment Instruction 3.B.8., Part 1, a.(3) of this service bulletin satisfies the requirements described in the Flight Safety Inspection Program for a modified support frame (bulkhead) access cutout inspection in accordance with service bulletin 747-53A2332 R3. (b) Accomplishment Instruction 3.B.8., Part 1, paragraph a.(5) gives instruction for an LFEC (and an alternative open hole HFEC) inspection of the support frame outer chord. The compliance time for the repeat inspection is different if the alternative open hole HFEC inspection is accomplished. (c) Accomplishment Instruction 3.B.8., Part 1, a.(6) gives instruction for an open hole HFEC inspection of the support frame outer chord and frame support fitting and a surface HFEC inspection of the support frame outer chord and the splice fittings. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 39 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 40 Group 1-3: Table 7: Support Frame Post-Modification Inspections - Part 2 & 3 Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Within 20,000 flight cycles after modification installation in accor- dance with Accomplishment Instruc- tions 3.B.1 through 3.B.6. Do an open hole high fre- quency eddy current (HFEC) inspection for cracks in the hinge sup- port in accordance with Accomplishment Instruc- tions 3.B.8., Part 2. All airplanes. Do support frame post- modification inspections for cracks in accordance with Accomplishment In- structions 3.B.8., Part 3, a.(1) and (2). -Before further flight.Contact Boeing for repair data, and do the repair. Any cracks found. 6,000 flight cycles-Do an open hole HFEC inspection for cracks in the hinge support in accor- dance with Accomplish- ment Instructions 3.B.8., Part 2. No cracks found. 3,000 flight cycles-Do support frame post- modification inspections for cracks in accordance with Accomplishment In- structions 3.B.8., Part 3, a.(1). 1,500 flight cycles-Do support frame post- modification inspections for cracks in accordance with Accomplishment In- structions 3.B.8., Part 3, a.(2). BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 40 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 41 Group 4-5: Table 8: Support Frame Post-Modification Inspections - Part 1 (LCF/SP) Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Within 3,000 flight cycles after modification installation in accor- dance with Accomplishment Instruc- tions 3.B.1 through 3.B.6, or within 1,500 flight cycles after the date on Revision 2 of this service bulletin, whichever occurs later. Do Support Frame Post- Modification Inspection in accordance with Accom- plishment Instructions 3.B.8., Part 1, a.(3). All airplanes. -Before 12,000 total flight cycles, or within 1,500 flight cycles after modification installation in accor- dance with Accomplishment Instruc- tions 3.B.1 through 3.B.6, or within 1,500 flight cycles after the date on Revision 2 of this service bulletin, whichever occurs later. Do Support Frame Post- Modification Inspections in accordance with Ac- complishment Instruc- tions 3.B.8., Part 1, a.(4), (5), (6) and (7). -Within 4,000 flight cycles after modification installation in accor- dance with Accomplishment Instruc- tions 3.B.1 through 3.B.6, or within 1,500 flight cycles after the date on Revision 3 of this service bulletin, whichever occurs later. Do Support Frame Post- Modification Inspections in accordance with Ac- complishment Instruc- tions 3.B.8., Part 1, a.(8), (9) and (10). 3,000 flight cyclesWithin 3,000 flight cycles after the last inspection. Do Support Frame Post- Modification Inspections in accordance with Ac- complishment Instruc- tions 3.B.8., Part 1, a.(3). No cracks found during 3.B.8., Part 1, a.(3) inspec- tion. 1,000 flight cyclesWithin 1,000 flight cycles after the last inspection. Do Support Frame Post- Modification Inspections in accordance with Ac- complishment Instruc- tions 3.B.8., Part 1, a.(4). No cracks found during 3.B.8., Part 1, a.(4) inspec- tion. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 41 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 42 Group 4-5: Table 8: Support Frame Post-Modification Inspections - Part 1 (LCF/SP) Repeat Interval (Not to Exceed) Compliance TimeActionCondition 1,000 flight cyclesWithin 1,000 flight cycles after the last inspection. At locations where a low frequency eddy current (LFEC) inspection was accomplished, do Sup- port Frame Post-Modifica- tion LFEC inspections in accordance with Accom- plishment Instruction 3.B.8., Part 1, a.(5). No cracks found during 3.B.8., Part 1, a.(5) inspec- tion. See note (a). 4,000 flight cyclesWithin 4,000 flight cycles after the last open hole HFEC inspection. At specific locations where an alternate open hole high frequency eddy current (HFEC) inspec- tion was accomplished, do Support Frame Post- Modification open hole HFEC inspections in ac- cordance with Accom- plishment Instruction 3.B.8., Part 1, a.(5). See note (a). 1,500 flight cyclesWithin 1,500 flight cycles after the last inspection. Repeat post-modification inspection in accordance with Accomplishment In- struction 3.B.8., Part 1, a.(6). No cracks found during 3.B.8., Part 1, a.(6) inspec- tion. See note (b). 4,000 flight cyclesWithin 4,000 flight cycles after the last open hole HFEC inspection. At specific locations where an alternate open hole high frequency eddy current (HFEC) inspec- tion was accomplished in accordance with Accom- plishment Instruction 3.B.8., Part 1, a.(5), re- peat post-modification in- spection in accordance with Accomplishment In- struction 3.B.8., Part 1, a.(6). See note (b). BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 42 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 43 Group 4-5: Table 8: Support Frame Post-Modification Inspections - Part 1 (LCF/SP) Repeat Interval (Not to Exceed) Compliance TimeActionCondition 1,500 flight cyclesWithin 1,500 flight cycles after the last inspection. Do Support Frame Post- Modification Inspections in accordance with Ac- complishment Instruc- tions 3.B.8., Part 1, a.(7). No cracks found during 3.B.8., Part 1, a.(7) inspec- tion. -Before further flight.Contact Boeing for repair data, and do the repair. Any cracks found during 3.B.8., Part 1, a.(3), (4), (5), (6) or (7) inspection. 2,000 flight cycles.Within 2,000 flight cycles after the last inspection. Do Support Frame Post- Modification Inspections in accordance with Ac- complishment Instruc- tions 3.B.8., Part 1, a.(8), (9) and (10). No cracks found during 3.B.8., Part 1, a.(8), (9) or (10) inspection. -Before further flight.Remove modification parts and do a surface high frequency eddy cur- rent (HFEC) inspection to determine if total crack length is within defined trim out limits in accor- dance with Accomplish- ment Instructions 3.B.12. Any cracks found during post-modification 3.B.8., Part 1, a.(8), (9) or (10) in- spection. -Before further flight.Contact Boeing for repair data, and do the repair. If total crack length extends outside the defined trim out limits. -Before further flight.Do an upper or lower corner post-modification web crack repair as appli- cable in accordance with Accomplishment Instruc- tions 3.B.12. If total crack length is within the defined trim out limits. 2,000 flight cyclesWithin 4,000 flight cycles after re- pair installation. Do Support Frame Post- Repair Inspection in ac- cordance with Accom- plishment Instructions 3.B.8., Part 4, a., b., or c. as applicable. Upper or lower corner post- modification web crack re- pair installed. (a) Accomplishment Instruction 3.B.8., Part 1, paragraph a.(5) gives instruction for an LFEC (and an alternative open hole HFEC) inspection of the support frame outer chord. The compliance time for the repeat inspection is different if the alternative open hole HFEC inspection is accomplished. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 43 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 44 Group 4-5: Table 8: Support Frame Post-Modification Inspections - Part 1 (LCF/SP) Repeat Interval (Not to Exceed) Compliance TimeActionCondition (b) Accomplishment Instruction 3.B.8., Part 1, a.(6) gives instruction for an open hole HFEC inspection of the support frame outer chord and frame support fitting and a surface HFEC inspection of the support frame outer chord and the splice fittings. (c) This is the more work requirement associated with Revision 4 of this service bulletin. Group 4-5: Table 9: Support Frame Post-Modification Inspections - Part 2 & 3 (LCF/SP) Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Within 12,000 flight cycles after modification installation in accor- dance with Accomplishment Instruc- tions 3.B.1 through 3.B.6. Do an open hole high fre- quency eddy current (HFEC) inspection for cracks in the hinge sup- port in accordance with Accomplishment Instruc- tions 3.B.8., Part 2. All airplanes. Do support frame post- modification inspections for cracks in accordance with Accomplishment In- structions 3.B.8., Part 3, a.(2), (3) and (4). -Before further flight.Contact Boeing for repair data, and do the repair. Any cracks found. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 44 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 45 Group 4-5: Table 9: Support Frame Post-Modification Inspections - Part 2 & 3 (LCF/SP) Repeat Interval (Not to Exceed) Compliance TimeActionCondition 6,000 flight cycles-Do an open hole HFEC inspection for cracks in the hinge support in accor- dance with Accomplish- ment Instructions 3.B.8., Part 2. No cracks found. 3,000 flight cycles-Do support frame post- modification inspections for cracks in accordance with Accomplishment In- structions 3.B.8., Part 3, a.(3). 1,500 flight cycles-Do support frame post- modification inspections for cracks in accordance with Accomplishment In- structions 3.B.8., Part 3, a.(2) and (4). Group 1-5: Table 10: Support Frame Aft Inner Chords - Inspection for Upper and Lower Corner Repairs Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Within 1,500 flight cycles after modification installation in accor- dance with Accomplishment Instruc- tions 3.B.1 through 3.B.6. or 1,000 flight cycles after the date on Revi- sion 2 of this service bulletin, which ever occurs later. Do a one-time General Visual Inspection (GVI) for repair(s) installed on the left and right side aft inner chords in accor- dance with Accomplish- ment Instructions 3.B.9. All airplanes with a support frame modification installed in accordance with the Original Issue of this ser- vice bulletin. -In accordance with Tables 6 and 7 or 8 and 9 as applicable. Do post-modification in- spections. Proceed to Tables 6 and 7 or 8 and 9 as applicable. No aft inner chord repair(s) installed. -Before further flight.Remove repair parts and the repaired aft inner chord, then contact Boe- ing for rework data and do the rework. (a) Any aft inner chord repair installed. (a) After rework or repairs are complete, support frame post-modification inspections are required. Group 1, Group 2 and Group 3 airplanes proceed in accordance with Table 6 and 7. Group 4 and Group 5 airplanes proceed in accordance with Table 8 and 9. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 45 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 46 Table 11: One Time Inspection at Location Added with Revision 4 Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Within 3,000 flight cycles after modifica- tion installation in ac- cordance with Accom- plishment Instruc- tions 3.B.1 through 3.B.6, or within 1,500 flight cycles after the date on Revision 4 of this service bulletin, whichever occurs lat- er. Do a one time sur- face HFEC inspec- tion of the support frame outer chord for cracks in accordance with Accomplishment Instruction 3.B.8., Part 1. (a) Airplanes that had post-modification in- spection accom- plished in accor- dance with Accom- plishment Instruction 3.B.8., Part 1, of Re- vision 3 of this ser- vice bulletin. -Before further flight.Contact Boeing for repair data, and do the repair. Crack found during the one time surface HFEC inspection of the outer chord. (a) This action is the more work requirement associated with Revision 4 of this service bulletin and it is iden- tified as such in Accomplishment Instruction 3.B.8., Part 1. This action is not necessary if the instruction given in Accomplishment Instruction 3.B.8., Part 1 states that it is not necessary. AD 2010-14-07 requires the modification specified in this service bulletin be made before the accumulation of 20,000 total flight cycles, or within 18 months after the effective date of the AD, whichever occurs later. F. Approval This service bulletin was examined by the Federal Aviation Administration (FAA). The changes specified in this service bulletin comply with the applicable regulations and are FAA approved, as well as European Aviation Safety Agency (EASA)/Joint Aviation Authorities (JAA) approved for all EASA/JAA approved airplanes listed in the service bulletin effectivity. This service bulletin and its approval were based on the airplane in its original Boeing delivery configuration or as modified by other approved Boeing changes. If an airplane has a non-Boeing modification or repair that affects a component or system also affected by this service bulletin, the operator is responsible for obtaining appropriate regulatory agency approval before incorporating this service bulletin. The Manager of the FAA Seattle Aircraft Certification Office (ACO) approves the inspections, repairs and modification with the corresponding compliance times specified in Tables 1 through 11 under paragraph 1.E., "Compliance," of SB 747-53A2473, Revision 4 as an AMOC to the inspections, repairs and modification at the STA 2598 support frame required by paragraphs (i), (j), (k)(1), (m), (n), (o), (p), (q), (r), (s), (t), (u) and (v) of AD 2010-14-07. When this SB specifies contacting Boeing for repair instructions, the repair instructions must be approved by the FAA in accordance with paragraph (x) of the AD. All provisions of AD 2010-14-07 that are not specifically referenced in this paragraph remain fully applicable and must be complied with. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 46 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 47 In addition, the Manager of the FAA Seattle ACO approves the inspections, repairs and modification with the corresponding compliance times specified in Table 6 and 7 under paragraph 1.E., "Compliance," of SB 747-53A2473, Revision 4 as an AMOC to the inspections and repairs at the STA 2598 support frame required by paragraphs (h), (i), and (j) of AD 2004-07-22 R1, for the inspection of Structural Significant Items (SSIs) F-49A, F-49B, F-49C, F-49D, F-49E, F-49F, F-49G, F-49H, F-49I, and F-49J of 747 Supplemental Structural Inspection Document (SSID) D6-35022, Revision G. This AMOC only applies to the areas that are modified as given in this service bulletin. When this SB specifies contacting Boeing for repair instructions, the repair instructions must be approved by the FAA in accordance with paragraph (l) of the AD. All provisions of AD 2004-07-22 R1 that are not specifically referenced in this paragraph remain fully applicable and must be complied with. In addition, the Manager of the FAA Seattle ACO approves the inspections, repairs and modification with the corresponding compliance times specified in Table 8 and 9 under paragraph 1.E., "Compliance," of SB 747-53A2473, Revision 4 as an AMOC to the inspections and repairs at the STA 2598 support frame required by paragraphs (h), (i), and (j) of AD 2004-07-22 R1, for the inspection of SSI F-49KK, F-49LL, F-49MM, F-49NN, and F-49PP of 747-400 LCF SSID Appendix A, D6-35022-1. This AMOC only applies to the areas that are modified as given in this service bulletin. When this SB specifies contacting Boeing for repair instructions, the repair instructions must be approved by the FAA in accordance with paragraph (l) of the AD. All provisions of AD 2004-07-22 R1 that are not specifically referenced in this paragraph remain fully applicable and must be complied with. G. Manpower The table below shows an estimate of the task hours necessary to do the modification and repair 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. Support Frame Modification Elapsed HoursTask-HoursNumber of Per- sons Task 6.0012.002Open Access/Install Support Tool (a)(a) 14.7529.502Inspection 1.503.002Crack/Repair Removal (b)(b) 24.0096.004Modification and no web crack repair installed 6.0012.002Close Access/Remove Support Tool 52.25152.50TOTAL FOR EACH SIDE OF AIRPLANE BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 47 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 48 Support Frame Modification Elapsed HoursTask-HoursNumber of Per- sons Task 25.25101.004Modification with web crack repair in- stalled at the same time. (c), (d) (c), (d) 53.50157.50TOTAL FOR EACH SIDE OF AIRPLANE (a) More or less time may be necessary due to the type of support installed. (b) More time will be necessary if cracks are found in the frame support fitting, hinge support fitting, or outer chord. (c) Modification with a typical upper or lower web repair installation. More time will be necessary if more than one repair is installed. (d) Includes Open Access/Install Support Tool; Inspection; Crack/Repair Removal; and Close Access/Remove Support Tool hours above. Support Frame Upper Corner Fastener Inspection/Rework Elapsed HoursTask-HoursNumber of Per- sons Task 1.503.002Fastener Inspection 1.503.002Surface HFEC Inspection 1.503.002Remove Fasteners 0.752.002Open Hole HFEC Inspection 0.751.502Zero-time Holes 1.503.002Fastener Installation 7.7515.50TOTAL FOR EACH AIRPLANE Support Frame Post-Modification Inspections Elapsed HoursTask-HoursNumber of Per- sons Task PART 1 16.0064.004Detailed Inspection 2.755.502HFEC Inspection (Floor Chord) 1.251.251LFEC Inspection 3.256.502Surface HFEC Inspection 3.256.502Open Hole HFEC Inspection 2.505.002Ultrasonic (UT) Inspection 3.757.502Post-Modification Inspection 32.7596.25PART 1 - TOTAL FOR EACH AIRPLANE BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 48 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 49 Support Frame Post-Modification Inspections Elapsed HoursTask-HoursNumber of Per- sons Task PART 2 2.505.002Access/Install Tool (a)(a) 22.5045.002Open Hole HFEC Inspection 2.505.002Close Access/Remove Tool 27.5055.00PART 2 - TOTAL FOR EACH AIRPLANE (b)(b) PART 3 6.0012.002Detailed Inspection 8.0016.002Surface HFEC Inspection 4.008.002LFEC Inspection 4.008.002Ultrasonic (UT) Inspection 22.0044.00PART 3 - TOTAL FOR EACH AIRPLANE (b)(b) PART 4 4.754.75Post-Repair Inspection 4.754.75PART 4 - TOTAL FOR EACH AIRPLANE 87.00200.00PART 1, 2, 3 & 4 - TOTAL FOR EACH AIRPLANE (b)(b) (a) Less time will be required if an internal stabilizer jack is not installed. (b) More time will be required if cracks are found and repairs are installed. H. Weight and Balance Changes NOTE: 1. Data for -100/-200/-400/SR (Short Range), and data for SP (Special Performance) and LCF (Large Cargo Freighter) model airplanes is given in different tables below. 747-100/-200/-300/-400/SR Change in Moment (Pound-Inches) Change in Weight (Pounds) Kits Used to Make Modification +30916.00+119.10148U0001-13/-14/- 15 +313838.40+120.80148U0001-13/-14/- 15 with one support frame upper corner web repair. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 49 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 50 747-100/-200/-300/-400/SR Change in Moment (Pound-Inches) Change in Weight (Pounds) Kits Used to Make Modification +318514.8+122.60148U0001-13/-14/- 15 with two support frame upper corner web repairs. +312279.6+120.20148U0001-13/-14/- 15 with support frame lower corner web repair. +316956.0+122.00148U0001-13/-14/- 15 with one support frame upper corner web repair and a lower corner web repair. +321632.4+123.80148U0001-13/-14/- 15 with two support frame upper corner web repairs and a lower web repair. 747SP Change in Moment (Pound-Inches) Change in Weight (Pounds) Kits Used to Make Modification +263823.0+119.00148U0001-13/-14/- 15 +268035.3+120.90148U0001-13/-14/- 15 with one support frame upper corner web repair. +272247.6+122.80148U0001-13/-14/- 15 with two support frame upper corner web repairs. +266483.4+120.20148U0001-13/-14/- 15 with support frame lower corner web repair. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 50 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 51 747SP Change in Moment (Pound-Inches) Change in Weight (Pounds) Kits Used to Make Modification +270695.7+122.10148U0001-13/-14/- 15 with one support frame upper corner web repair and a lower corner web repair. +274908.0+124.00148U0001-13/-14/- 15 with two support frame upper corner web repairs and a lower corner web repair. 747LCF (Large Cargo Freighter) Change in Moment (Pound-Inches) Change in Weight (Pounds) Kits Used to Make Modification +323442.0+119.00148U0001-13/-14/- 15 +328606.2+120.90148U0001-13/-14/- 15 with one support frame upper corner web repair. +333770.4+122.80148U0001-13/-14/- 15 with two support frame upper corner web repairs. +326703.6+120.20148U0001-13/-14/- 15 with support frame lower corner web repair. +331867.8+122.10148U0001-13/-14/- 15 with one support frame upper corner web repair and a lower corner web repair. +337032.0+124.00148U0001-13/-14/- 15 with two support frame upper corner web repairs and a lower corner web repair. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 51 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 52 I. Electrical Load Data Not applicable. J. References 1. Existing Data: a. 747-100/200/300 Aircraft Maintenance Manual (AMM) 27-41-02 b. 747-400 Aircraft Maintenance Manual (AMM) 27-41-02, 28-17-00, 28-26-00 c. 747 Non-Destructive Testing (NDT) Manual, Part 4, 53-10-10, Part 6, 51-00-00, Part 6, 53-30-00. d. 747 Nondestructive Test (NDT) Manual D6-7170, Part 6, Subject 51-00-00, Figures 1, 4, 11, 16 or 23. e. Boeing service bulletin 747-53A2427, FUSELAGE - Tail Section - Body Station 2598 Bulkhead Forward and Aft Inner Chord Inspection f. Boeing service bulletin 747-53A2467, FUSELAGE - Tail Section - Body Station 2598 Bulkhead Inner Chord, Outer Chord and Diagonal Brace Inspection g. Boeing Service Bulletins 747-53A2449, FUSELAGE - Tail Section - Body Station 2598 Bulkhead Frame Support Inspection Under the Horizontal Stabilizer Hinge Support Fittings h. FAA Airworthiness Directive 2001-14-07, Amendment 39-12318 i. FAA Airworthiness Directive 2001-15-03, Amendment 39-12337 j. FAA Airworthiness Directive 2003-19-08, Amendment 39-13311 k. FAA Airworthiness Directive 2006-05-06, Amendment 39-14503 l. FAA Airworthiness Directive 2010-14-07, Amendment 39-16352 m. Service Related Problem (SRP) 747OP-SRP-53-0106; 747-SRP-53-0118; 747-SRP-53-0145; 747-SRP-0341. n. Standard Overhaul Practices Manual (SOPM) 20-41-02, 20-43-03, 20-50-19 2. Data supplied with this Service Bulletin: a. Drawings: BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 52 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 53 ADCNDCN/REVSheetTitleDrawing No -E1BULKHEAD REINFORCEMENT STA 2598624U0061 -C2 -C3 -D4 --6 -B7 3. Installation Drawings Used in the Preparation of this Service Bulletin: TitleDrawing Number Bulkhead Instl - Upper Lobe, Sta 259865B02502 Bulkhead Instl - Lower Lobe, Sta 259865B02505 These drawings were used to prepare this service bulletin. These drawings are not necessary to make the specified changes, and are not supplied with this service bulletin. These drawings may not be applicable to all airplane configurations or operators. K. Publications Affected 1. Publications None. 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 and new 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. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 53 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 54 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 54 of 250 BOEING SERVICE BULLETIN 747-53A2473 BLANK PAGE ### Page 55 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 REFER TO THE BOEING PART PAGE ON MYBOEINGFLEET.COM OR CONTACT FIRST RESPONDER AT FR@BOEING.COM FOR THE LATEST QUANTITY INFORMATION. Unit Price as of the Revi- sion date of this Service Bulletin (US Dollars) ROLT as of the Revi- sion date of this Ser- vice Bulletin (Calendar Days) NameKit Number $63,882.00550Top Kit - Modification148U0001-15 $146.00228Supplemental Kit - Bolt148U0001-12 $20,939.00244Top Kit - Chord, LS148U0001-13 $20,939.00244Top Kit - Chord, RS148U0001-14 $4,079.00550Kit - Local Upper Repair, STA 2598, Left Side 148U0001-35 (a) $4,460.00550Kit - Local Upper Repair, STA 2598, Right Side 148U0001-36 (a) $4,317.00550Kit - Local Upper Repair, STA 2598, Left Side 148U0001-37 (b) $4,319.00550Kit - Local Upper Repair, STA 2598, Right Side 148U0001-38 (b) $3,593.00550Kit - Local Upper Repair, STA 2598, Left Side 148U0001-39 (c) $3,593.00550Kit - Local Upper Repair, STA 2598, Right Side 148U0001-40 (c) $3,586.00550Kit - Local Upper Repair, STA 2598, Left Side 148U0001-41 (d) $3,586.00550Kit - Local Upper Repair, STA 2598, Right Side 148U0001-42 (d) $3,881.00550Kit - Local Upper Repair, STA 2598, Left Side 148U0001-43 (e) BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 55 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 56 Unit Price as of the Revi- sion date of this Service Bulletin (US Dollars) ROLT as of the Revi- sion date of this Ser- vice Bulletin (Calendar Days) NameKit Number $3,881.00550Kit - Local Upper Repair, STA 2598, Right Side 148U0001-44 (e) $3,741.00550Kit - Local Upper Repair, STA 2598, Left Side 148U0001-45 (f) $3,741.00550Kit - Local Upper Repair, STA 2598, Right Side 148U0001-46 (f) $3,870.00550Kit - Local Lower Repair, STA 2598, Left Side 148U0001-48 (g) $2,553.00550Kit - Local Lower Repair, STA 2598, Left Side 148U0001-49 (h) (a) Group 1, 4, Configuration 3 (b) Group 2-3, Configuration 5; Group 5 (c) Group 1, 4, Configuration 2 (d) Group 2, Configuration 2, 4; Group 3, Configuration 2, 4 (e) Group 1, 4, Configuration 1 (f) Group 2, Configuration 1, 3; Group 3, Configuration 1, 3; Group 5 (g) Group 1, Configuration 3; Group 2-3, Configuration 5; Group 4, Configuration3; Group 5 (h) Group 1, Configuration 1-2; Group 2, Configuration 1-4; Group 3, Configuration1-4; Group 4, Configuration1- 2 B. Industry Support Information Boeing warranty remedies are not available for the configuration changes, inspection and/or repair procedures given in 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. Kit 148U0001 Existing PartNameQTYNew Part Number NotesNumber-1-10-11-12-15-2-7 Kit- Reinforce- ment -...1..148U0001-1 Kit- Fasten.-.-.1.148U0001-10 (f)Kit- Bolt1.-..1.148U0001-11 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 56 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 57 Kit 148U0001 Existing PartNameQTYNew Part Number NotesNumber-1-10-11-12-15-2-7 (f)Supplemental Kit - Bolt ...-1..148U0001-12 Top Kit...--..148U0001-15 Kit- Reinforce- ment ...1-.148U0001-2 Kit- Parts1....-148U0001-7 Kit- Parts....1.148U0001-8 Kit- Fasten1.....148U0001-9 (e)Doubler.....1148U0011-1 Filler.....1148U0011-3 Doubler.....1148U0011-5 Filler.....1148U0011-7 Bolt..6...BACB30LT5K11 Bolt..1...BACB30NM8K15 Bolt..1...BACB30NM8K16 Bolt.1....BACB30NW6K10Y Bolt.5....BACB30NW6K8Y Bolt.2....BACB30NX10K10 Bolt.2....BACB30NX10K11 Bolt.2....BACB30NX10K12 Bolt.8....BACB30NX10K13 Bolt.8....BACB30NX10K13X Bolt.3....BACB30NX10K14 Bolt.2....BACB30NX10K14X Bolt.10....BACB30NX10K7 Bolt.4....BACB30NX10K8 Bolt.2....BACB30NX12K13 Bolt.4....BACB30NX12K14 Bolt.6....BACB30NX12K14X Bolt.2....BACB30NX12K15 Bolt.1....BACB30NX12K16 Bolt.12....BACB30NX6K10X BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 57 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 58 Kit 148U0001 Existing PartNameQTYNew Part Number NotesNumber-1-10-11-12-15-2-7 Bolt.2....BACB30NX6K11X Bolt.1....BACB30NX6K13X Bolt.8....BACB30NX6K3X Bolt.5....BACB30NX6K7Y Bolt.1....BACB30NX6K8Y Bolt.23....BACB30NX6K9X Bolt.5....BACB30NX8K10 Bolt.29....BACB30NX8K10X Bolt.4....BACB30NX8K11 Bolt.23....BACB30NX8K11X Bolt.10....BACB30NX8K12X Bolt.2....BACB30NX8K13 Bolt.21....BACB30NX8K13X Bolt.16....BACB30NX8K14X Bolt.1....BACB30NX8K15X Bolt.9....BACB30NX8K16X Bolt.5....BACB30NX8K17X Bolt.52....BACB30NX8K5 Bolt.25....BACB30NX8K6 Bolt.29....BACB30NX8K7 Bolt.36....BACB30NX8K8 Bolt.8....BACB30NX8K8X Bolt.28....BACB30NX8K9 Bolt.36....BACB30NX8K9X Bolt..6...BACB30US4K14 Bolt..6...BACB30US4K15 Bolt..2...BACB30US8K34 Bolt..2...BACB30US8K37 Bolt..2...BACB30US9K34 Bolt..2...BACB30US9K37 Bolt..4...BACB30US9K38 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 58 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 59 Kit 148U0001 Existing PartNameQTYNew Part Number NotesNumber-1-10-11-12-15-2-7 Bolt...6...BACB30UU5K13 Bolt..2...BACB30UU5K15 Bolt..4...BACB30UU5K16 Bolt..2...BACB30UU5K17 Bolt..4...BACB30UU7K15 Bolt..4...BACB30UU7K16 Bolt..2...BACB30UU8K15 Bolt..2...BACB30UU8K16 Collar.6....BACC30AC6 Collar.31....BACC30BH10 Collar.15....BACC30BH12 Collar.46....BACC30BH6 Collar.339....BACC30BH8 Collar.6....BACC30R6 Nut..12...BACN10HR4CD Nut..8...BACN10HR9CD Nut..8...BACN10JC5CD Nut..8...BACN10JC7CD Nut..4...BACN10JC8CD Nut...6...BACN10YR5CD Rivet.8....BACR15BB6D5C Rivet.6....BACR15GF3D5 Shim.....1BACS40R011D036F Shim.....1BACS40R011D040F Shim.....1BACS40R012D037F Shim.....1BACS40R012D041F 65B02872-3Shim.....2BACS40R036B065F Washer..2...BACW10AT28AS Washer..2...BACW10AT48AS Washer...6...BACW10BN5AC Washer..12...BACW10BP4CK BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 59 of 250 BOEING SERVICE BULLETIN 747-53A2473 ### Page 60 Kit 148U0001 Existing PartNameQTYNew Part Number NotesNumber-1-10-11-12-15-2-7 Washer..12...BACW10BP4PK Washer..8...BACW10BP9CK Washer..8...BACW10BP9PK Washer..14...NAS1149D0516J Washer...12...NAS1149D0563J Washer..8...NAS1149D0716J Washer..4...NAS1149D0816J Nut..3...NAS1805-5 Nut..2...NAS1805-8 (a)65B02875-13Fitting.....165B02875U13 (b)65B02875-15Fitting.....165B02875U15 (c)65B02875-17Fitting.....165B02875U17 (d)65B02875-19.Fitting.....165B02875U19 (a) 65B02875U27 is an acceptable substitute for the 65B02875U13. (b) 65B02875U29 is an acceptable substitute for the 65B02875U15. (c) 65B02875U31 is an acceptable substitute for the 65B02875U17. (d) 65B02875U33 is an acceptable substitute for the 65B02875U19. (e) 148U0011-15 is an acceptable substitute for the 148U0011-1. (f) 148U0001-12 is a required supplemental kit with the 148U0001-11 bolt kit. Kit 148U0001 Existing PartNameQTYNew Part Number NotesNumber-13-14 Top Kit, Kit- Chord-.148U0001-13 Top Kit, Kit- Chord.-148U0001-14 65B02505-49Chord1.65B02505U49 65B02505-50Chord.165B02505U50 Kit 148U0001 Existing PartNameQTYNew Part Number NotesNumber-8-9 Kit- Parts-.148U0001-8 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 24, 2005 747-53A2473Revision 4: December 01, 2011 60 of 250 BOEING SERVICE BULLETIN 747-53A2473 The text continues at https://openairdocs.org/service-documents/boeing/747-53a2473/file/6c7ad8329392.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.