# Boeing Alert Service Bulletin 747-53A2452: Revision 1 - Rights: © The Boeing Company. Filed by the FAA in regulations.gov docket FAA-2015-3983; AD 2016-07-03 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. - Document: [Boeing Alert Service Bulletin 747-53A2452](https://openairdocs.org/service-documents/boeing/747-53a2452.md) - Title as filed: U.S. DOT/FAA - SB-747-53A2452-01 - Pages: 142 - PDF: https://openairdocs.org/files/sha256/8a/f7/8af7982f91b0db6ac81a155fecd32e6333141a1327f28dd202a483b93ce07db8 - Page: https://openairdocs.org/service-documents/boeing/747-53a2452/file/8af7982f91b0 ## 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 ALERT Number: 747-53A2452 Original Issue: April 03, 2003 Revision 1: July 16, 2012 ATA System: 5321 SUBJECT: FUSELAGE - Floors - Upper Deck Floor Beam Upper Chord Inspection and Repair Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15 CFR 300-774). An export license may be required before it is used for development, production or use by foreign persons from specific countries. The controller of this data has the individual responsibility to abide by all export laws. 9E991ECCN: BOEING PROPRIETARY, CONFIDENTIAL AND/OR TRADE SECRET Copyright © 2003 Boeing. Unpublished Work. All Rights Reserved. Treatment of this document and its content is governed by contract with Boeing. Rights to use this document are licensed on a per aircraft basis and such rights may not be transferable. For more information, contact The Boeing Company. Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, Dreamliner™, BBJ, DC-8, DC-9, DC-10, KC-10, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8A, Poseidon and Boeing liveries are all trademarks owned by The Boeing Company; and no trademark license is granted in connection with this document unless provided in writing by Boeing. BOEING is a trademark of Boeing Management Company. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 1 of 142 4.0 ### Page 2 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 2 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT BLANK PAGE ### Page 3 Table of Contents Revision Transmittal Sheet ............................................ 5 Summary ...................................................... 9 1. PLANNING INFORMATION ........................................ 1 3 A. Effectivity ............................................... 1 3 1. Airplanes ............................................ 1 3 2. Spares Affected ........................................ 2 0 B. Concurrent Requirements ...................................... 2 0 C. Reason ................................................ 2 0 D. Description .............................................. 2 1 E. Compliance .............................................. 2 2 F. Approval ............................................... 4 5 G. Manpower .............................................. 4 6 H. Weight and Balance Changes .................................... 4 8 I. Electrical Load Data ......................................... 4 8 J. References .............................................. 4 8 1. Existing Data: ......................................... 4 8 2. Data Supplied with this Service Bulletin: ........................... 4 8 3. Installation Drawings Used in the Preparation of this Service Bulletin: ........... 4 8 K. Publications Affected ........................................ 4 8 L. Interchangeability and Intermixability of Parts ........................... 4 9 M. Software Accomplishment Summary ................................ 4 9 2. MATERIAL INFORMATION ........................................ 5 1 A. Material - Price and Availability ................................... 5 1 B. Industry Support Information .................................... 5 1 C. Parts Necessary for Each Airplane ................................. 5 1 1. Kits/Parts: ........................................... 5 1 2. Parts and Materials Supplied by the Operator: ........................ 5 1 3. Parts Modified and Reidentified: ............................... 5 4 4. Parts Removed and Not Replaced: .............................. 5 4 D. Parts Necessary to Change Spares ................................. 5 4 E. Special Tooling - Price and Availability ............................... 5 4 F. Special Tooling Necessary to do this Service Bulletin ....................... 5 4 3. ACCOMPLISHMENT INSTRUCTIONS .................................. 5 5 A. GENERAL INFORMATION ..................................... 5 5 B. WORK INSTRUCTIONS ....................................... 5 7 FIGURE 1: THIS FIGURE IS DELETED .................................. 6 4 FIGURE 2: INSPECTION AREA DEFINITIONS .............................. 6 5 FIGURE 3: OPEN-HOLE HFEC INSPECTION AT FLOOR PANEL ATTACHMENT FASTENER LOCATIONS .................................................. 8 1 FIGURE 4: FLOOR PANEL ATTACHMENT FASTENER - HOLE MODIFICATION ........... 8 3 FIGURE 5: CLIPNUT MODIFICATION AND SURFACE HFEC INSPECTION .............. 8 5 FIGURE 6: HOLE MEASUREMENTS AFTER CRACK REMOVAL ................... 8 9 FIGURE 7: REPAIR STRAP INSTALLATION ............................... 9 1 FIGURE 8: UPPER CHORD TRIM ..................................... 9 6 FIGURE 9: UPPER CHORD TRIM REPAIR WITH STRAP (REPAIR #7) ............... 1 0 0 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 3 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 4 FIGURE 10: UPPER CHORD TRIM REPAIR WITH STRAP AND CLIP (REPAIR #6) ......... 1 0 5 FIGURE 11: UPPER CHORD THICK FLANGE REPAIR WITH STRAP (REPAIR #8) ......... 1 1 0 FIGURE 12: UPPER CHORD THICK FLANGE REPAIR WITH ANGLE (REPAIR #9) ......... 1 1 5 FIGURE 13: UPPER CHORD THIN FLANGE REPAIR WITH STRAP (REPAIR #11) .......... 1 2 0 FIGURE 14: UPPER CHORD THIN FLANGE REPAIR WITH ANGLE (REPAIR #12) ......... 1 2 5 FIGURE 15: AFTER-REPAIR INSPECTION FOR LOCATIONS WITH THE STRAP REPAIR ..... 1 3 0 FIGURE 16: AFTER-REPAIR INSPECTIONS FOR LOCATIONS WITH UPPER CHORD TRIM REPAIR WITH STRAP OR ANGLE .................................. 1 3 2 FIGURE 17: OPEN-HOLE HFEC INSPECTION OF AREA 3 ....................... 1 3 4 FIGURE 18: SURFACE HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTION AT PERMANENT FASTENER LOCATIONS .................................. 1 3 8 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 4 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 5 Commercial Airplanes 747 Service Bulletin ALERT Revision Transmittal SheetNumber: 747-53A2452Original Issue: April 03, 2003 Revision 1: July 16, 2012 ATA System: 5321 SUBJECT: FUSELAGE - Floors - Upper Deck Floor Beam Upper Chord Inspection and Repair This revision includes all pages of the service bulletin. COMPLIANCE INFORMATION RELATED TO THIS REVISION More work is necessary on the airplane(s) inspected in accordance with the original issue of this service bulletin. Inspection of permanent fastener locations in Area 1 and Area 2 have been added. Also, initial inspection compliance times have been reduced for all inspection areas. Refer to Paragraph 1.E., Compliance, for details. Federal Aviation Administration (FAA) Airworthiness Directives AD 2005-20-29 and AD 2004-07-22 R1 are related to this service bulletin. REASON FOR REVISION This revision is sent to reduce initial inspection compliance times, add replacement requirements for upper deck floor beam upper chords, and add inspection requirements at all permanent fastener locations common to the affected upper deck floor beam upper and lower chords. These sections were changed: 1. In Summary: Updated the Background section. Added Planning Data table. Revised Action section to reflect new inspection requirements. Revised Effectivity description. Added related Airworthiness Directive (AD) statement. Revised Manpower estimates. Updated Summary Illustration. 2. In Paragraph 1.C., Reason: Updated reason information and changed Airworthiness Directive reference. 3. In Paragraph 1.D., Description: A surface HFEC inspection at permanent fastener locations is added. Maintenance zone tables are added. "Permanent" fastener locations are defined as all fastener locations, except floor panel attachment fastener locations. 4. In Paragraph 1.E., Compliance: New AD references are added. New compliance times and new compliance tables have been added. 5. In Paragraph 1.F., Approval: Updated approval statement and added Alternative Method of Compliance (AMOC) statements. 6. In Paragraph 1.G., Manpower: Manpower estimates are revised. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 5 of 142 ### Page 6 7. In Paragraph 1.H., Weight and Balance Changes: Added explanation of possible weight and balance changes. 8. In Paragraph 1.J., References: Reference to new Airworthiness Directives and Structural Repair Manual are added. 9. In Paragraph 1.K., Publications Affected: Structural Repair Manual references are added to the publications list and a damage tolerance based structural inspection statement is added. 10. In Paragraph 3.A., General Information: The notes section is updated. 11. In Paragraph 3.B., Work Instructions: Existing work instructions have been re-organized and revised for clarification. Repair options for floor panel attachment holes are clarified and numbered. Also, new inspection requirements at permanent fastener locations is added. 12. FIGURE 1: This Figure is deleted. In the original issue of this service bulletin, Figure 1 was a logic diagram. The information previously contained in Figure 1 is now included in Paragraph 1.E., Compliance. 13. FIGURE 2: The inspection area definitions are updated. 14. FIGURE 4: The edge margin measurement is clarified. 15. FIGURE 6: The edge margin measurement is clarified. 16. FIGURE 7: The FWD arrow is corrected in view B-B. A note is added. 17. FIGURE 8: Revised footnote to clarify trim depth measurement. 18. FIGURE 9: The FWD arrow is corrected in view B-B. A note is added. The figure title is changed. 19. FIGURE 10: The FWD arrow is corrected in view B-B. A note is added. The figure title is changed. 20. FIGURE 11: The Figure title is changed. A note for clarification of flange thickness is added. 21. FIGURE 12: The Figure title is changed. A note for clarification of flange thickness is added. 22. FIGURE 13: The Figure title is changed. A note for clarification of flange thickness is added. 23. FIGURE 14: The Figure title is changed. A note for clarification of flange thickness is added. 24. FIGURE 15: A note is added. 25. FIGURE 16: A note is added. 26. FIGURE 18: A new inspection figure is added. 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. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 6 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 7 REVISION HISTORY April 03, 2003Original Issue: July 16, 2012Revision 1: Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 7 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 8 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 8 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT BLANK PAGE ### Page 9 Commercial Airplanes 747 Service Bulletin ALERT SummaryNumber: 747-53A2452Original Issue: April 03, 2003 Revision 1: July 16, 2012 ATA System: 5321 SUBJECT: FUSELAGE - Floors - Upper Deck Floor Beam Upper Chord Inspection and Repair THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH 1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO THE NEW OWNER. CONCURRENT REQUIREMENTS None BACKGROUND Accomplishment of the inspections shown in this service bulletin will ensure the structural integrity of the upper chords of the upper deck floor beams. Cracks in these chords that are not found and repaired could become large and cause the floor beam to become severed. This can lead to large deflection or deformation of the floor and of the body skin, frames, and stringers. This deflection or deformation could result in damage to wire bundles and unintended inputs to the flight control cables which could affect airplane controllability. Multiple adjacent severed floor beams could result in rapid decompression of the airplane. Flight critical wire bundles and control cables are routed through cutouts in the upper deck floor beams. Upper deck floor beam upper chord cracks were found on Boeing's 747-SR Fatigue Test airplane, which accumulated 20,000 full pressure flight-cycles and an additional 20,000 test cycles. Numerous upper chord cracks were also reported by several operators accomplishing the inspections in accordance with Boeing Service Bulletin 747-53A2349, "Fuselage - Inspections Based on Fatigue Test Results." A structural reassessment of the 747 airplane was conducted under the requirements of Federal Aviation Administration (FAA) Advisory Circular 91-56, in accordance with Federal Aviation Regulation (FAR) 25.571 as amended in 1978, to ensure safe operation of 747 airplanes throughout their operational life. From this requirement, the Section 41 upper deck floor beam upper chords were determined to be significant, in that they are critical to airplane structural integrity. Therefore, a flight safety inspection program which will continue throughout the operational life of the airplane is specified in this service bulletin. The inspections shown in this service bulletin were previously included in Revision 1 of Boeing Service Bulletin 747-53A2349, "Fuselage - Inspections Based on Fatigue Test Results." Upper chord HFEC inspections are required by FAA Airworthiness Directive (AD) AD 2005-20-29. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 9 of 142 ### Page 10 The initial inspection compliance time to start High Frequency Eddy Current (HFEC) inspections of upper deck floor beam upper chords that were previously in Service Bulletin 747-53A2349, Revision 1 was reduced for the original issue of this service bulletin because of the critical nature of the header floor beams that reinforce the upper deck floor stairway cutouts. The Area 3 inspections were included to address a location where cracks were found on Boeing's 747SR Fatigue Test airplane, but was not included in Service Bulletin 747-53A2349. The initial inspection compliance times have been further reduced in Revision 1 of this service bulletin to align with the initial inspection compliance times for Supplemental Structural Inspection Document (SSID) D6-35022 requirements for the same structure. Boeing Service Related Problem (SRP) 747-SRP-53-0122 is related to this service bulletin. Subsequent to the original issue of this service bulletin, Boeing has determined that upper deck floor beam upper chords are susceptible to Widespread Fatigue Damage (WFD). Ongoing inspection of this structure is not sufficient to maintain an acceptable level of safety. Therefore, Boeing plans to issue another service bulletin that will recommend replacement of the upper chords. Accomplishment of the upper chord replacement service bulletin will terminate the inspection requirements of this service bulletin. For more information on WFD, refer to Boeing Service Letter 747-SL-53-088A. This table is provided to operators for planning purposes only. Refer to the applicable sections for more information. ReferenceAffectedPlanning Data Paragraph 1.A.2., Spares AffectedNoSpares Affected Paragraph 1.E., ComplianceYesAD Related Paragraph 1.H., Weight and Balance ChangesYesWeight and Balance Change Paragraph 1.I., Electrical Load DataNoElectrical Load Changed Paragraph 1.K., Publications AffectedNoPublications Affected Paragraph 1.K., Publications AffectedNoAirplane Flight Operations Affected (Flight Crew Operations Manual and/or FAA Approved Air- plane Flight Manual) Paragraph 2.C.1., Kits/PartsNoKits/Parts Required Paragraph 2.C.2., Parts and Materials Supplied by the Operator YesOperator Supplied Material Paragraph 2.F., Special Tooling Necessary to do this Service Bulletin NoSpecial Tooling Required ACTION Get access from above or below to the upper chord of the upper deck floor beams from STA 380 aft. If access is gained from above, do open-hole HFEC inspections for cracks at floor panel attachment fastener holes in the upper chords. If access is gained from below, modify the clipnuts for the floor panel attachment fasteners in accordance with this service bulletin and do surface HFEC inspections of the forward and aft horizontal flanges of the upper chord. If any crack is found, do a repair as shown in this service bulletin. If no cracks are found, do the inspection again at the time shown in Paragraph 1.E., Compliance. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 10 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 11 Get access to the upper and lower chord of the upper deck floor beams at the location in accordance with this service bulletin. Do surface HFEC inspection for cracks in the upper and lower chords of the upper deck floor beams at permanent fastener locations. If any crack is found, contact Boeing for repair instructions, and do the repair. If no cracks are found, do the inspection again at the time in accordance with Paragraph 1.E., Compliance . For areas repaired as shown in this service bulletin, start to do repeat inspections at repaired locations as shown in this service bulletin at the times shown in Paragraph 1.E., Compliance. For any locations that have a repair that is different from those shown in this service bulletin, contact Boeing for an after-repair inspection plan. EFFECTIVITY 747-100, 747-100B, 747-100B SUD, 747-200B, 747-300, 747SP, and 747SR airplanes. Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplanes. COMPLIANCE Federal Aviation Administration (FAA) Airworthiness Directives AD 2005-20-29 and AD 2004-07-22 R1 are related to this service bulletin. Refer to Paragraph 1.E., Compliance. INDUSTRY SUPPORT INFORMATION Boeing warranty remedies are not available for the inspection and repair procedures given in this service bulletin. MANPOWER Elapsed Time (Hours) Total Man-Hours Airplanes 106.25670.00Group 1 89.75538.00Group 2 118.75720.00Group 3 92.25548.00Group 4 158.00884.00Group 5 94.75558.00Group 6 MATERIAL INFORMATION None Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 11 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 12 (OCR) BOEING SERVICE BULLETIN 747-53A2452 ALERT ALERT SEE A GROUPS 1-4: INSPECT STA 380-800 GROUP 5: INSPECT STA 380-1100 GROUP 6: INSPECT STA 380-860 FWD < (TYPICAL) FLOOR PANEL DO HFEC INSPECTION OF THE UPPER CHORDS OF THE UPPER DECK FLOOR BEAMS FOR CRACKS AT THE FLOOR PANEL ATTACHMENT FASTENER HOLES AND DO SURFACE HFEC INSPECTION UPPER CHORD AT PERMANENT FASTENER LOCATIONS WEB FLOOR PANEL ATTACHEMENT HOLES TYPICAL UPPER CHORD CRACK ›PERMANENT FASTENER LOCATIONS LOWER CHORD ALSO DO SURFACE HFEC INSPECTIONS AT PERMANENT • INBD FASTENER LOCATIONS ON TYPICAL UPPER DECK FLOOR BEAM SOME LOWER CHORDS V67425 Original Issue: April 03, 2003 Revision 1: July 16, 2012 PROPRIETARY - Copyright © Unpublished Export Controlled ECCN: 9E991 - BOEING 747-53A2452 Work - See page 1 for details. 12 of 142 ### Page 13 Commercial Airplanes 747 Service Bulletin ALERT Number: 747-53A2452 Original Issue: April 03, 2003 Revision 1: July 16, 2012 ATA System: 5321 SUBJECT: FUSELAGE - Floors - Upper Deck Floor Beam Upper Chord Inspection and Repair THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH 1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO THE NEW OWNER. 1. PLANNING INFORMATION A. Effectivity 1. Airplanes Refer to Service Bulletin Index Document D6-30300, Part 3 for Airplane Variable Number, Line Number, and Serial Number data. NOTE: Group 1 airplanes modified by Boeing to the Special Freighter configuration should be considered to be Group 2 airplanes. 1. 2. Group 3 airplanes modified by Boeing to the Special Freighter configuration should be considered to be Group 4 airplanes. 3. Group 5 airplanes modified by Boeing to the Special Freighter configuration should be considered to be Group 6 airplanes. This service bulletin is for the airplanes shown below. DESCRIPTIONCONFIGURATIONGROUP 747-100, 747-100B, 747-200B, 747-SP, and 747-SR Passenger airplanes with the circular stairway cutout, except those modified by Boeing to the Special Freighter configuration -1 747-100, 747-100B, 747-200B, and 747-SR airplanes with the circular stairway cutout that have been modified by Boeing to the Special Freighter configuration. -2 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 13 of 142 ### Page 14 DESCRIPTIONCONFIGURATIONGROUP 747-100,747-100B, 747-200B, 747-SP, and 747-SR Passenger airplanes with the forward straight stairway cutout, except those modified by Boeing to the Special Freighter configuration. -3 747-100, 747-100B, 747-200B, and 747-SR airplanes with the forward straight stairway cutout that have been modified by Boeing to the Special Freighter configuration. -4 Stretched upper deck 747-100 (747-100BSUD), stretched upper deck 747-200B, and 747-300 airplanes except those modified by Boeing to the Special Freighter configuration. -5 Group 5 airplanes that have not had STA 860 and STA 980 floor beams modified in accordance with Service Bulletin 747-53A2327. 1 Group 5 airplanes that have had STA 860 and STA 980 floor beams modified in accordance with Service Bulletin 747-53A2327. 2 Stretched upper deck 747-100 (747-100BSUD), stretched upper deck 747-200B, and 747-300 airplanes that have been modified by Boeing to the Special Freighter configuration. -6 Airplane Models: 747-100, 747-100B, 747-100B SUD, 747-200B, 747-300, 747SP, 747SR GroupVariable Number 1RA001 - RA025 2RA026 1RA027 - RA028 2RA029 1RA030 - RA032 2RA033 1RA034 2RA101 - RA103 1RA104 - RA110 2RA111 - RA112 1RA113 - RA115 2RA161 - RA163 1RA164 1RA201 - RA203 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 14 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 15 GroupVariable Number 1RA216 - RA217 1RA245 - RA246 1RA251 - RA266 1RA301 - RA318 1RA351 - RA360 1RA369 - RA373 1RA401 - RA418 1RA501 - RA502 1RA521 - RA523 2RA524 1RA525 - RA528 1RA532 - RA548 1RA551 - RA552 1RA559 - RA561 1RA581 - RA582 1RA585 1RA601 - RA602 1RA631 2RA632 1RA633 2RA634 - RA635 1RA651 - RA652 1RA671 - RA677 1RA701 - RA702 1RA721 - RA731 1RA741 - RA745 1RA749 - RA750 1RA761 - RA762 1RA781 - RA784 2RA901 - RA902 1RA903 - RA909 2RA910 - RA916 1RB001 - RB016 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 15 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 16 GroupVariable Number 2RB041 1RB042 2RB043 1RB044 1RB071 - RB075 1RB101 - RB102 1RB411 - RB413 1RB421 1RB601 - RB603 2RB604 - RB605 1RB606 2RB607 1RB681 - RB695 2RB696 1RB697 1RB711 1RB721 - RB723 1RB741 - RB748 1RD001 - RD004 1RD021 - RD022 2RD041 1RD042 2RD043 - RD044 1RD045 - RD054 2RD055 1RD056 - RD059 1RD071 - RD072 1RD081 2RD082 - RD083 1RD091 - RD092 1RD101 - RD104 1RD121 - RD127 1RD131 - RD141 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 16 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 17 GroupVariable Number 2RD142 1RD143 2RD144 1RD166 - RD167 1RD171 - RD172 1RD181 - RD183 3RD201 - RD204 1RD221 - RD226 2RD227 1RD231 - RD232 2RD233 - RD234 1RD235 3RD241 - RD243 1RD251 - RD262 1RD271 - RD272 1RD291 - RD292 4RD301 3RD302 1RD311 1RD351 - RD357 2RD358 4RD361 - RD366 5RD381 - RD383 4RD411 - RD412 3RD413 - RD414 1RD421 - RD426 1RD431 - RD435 4RD441 - RD442 1RD451 - RD456 2RD461 3RD471 - RD475 1RD513 - RD519 1RD531 - RD533 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 17 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 18 GroupVariable Number 2RD551 1RD561 1RD571 4RD581 - RD583 1RD591 - RD593 6RD601 - RD602 5RD603 - RD607 1RD621 2RD622 - RD623 2RD641 - RD643 1RD644 - RD645 2RD646 1RD647 - RD649 1RD651 - RD659 1RD661 1RD671 1RD681 - RD682 2RD691 1RD692 1RD701 - RD702 5RD721 - RD722 3RD741 - RD742 1RD751 2RD752 1RD753 - RD755 1RD761 1RD771 - RD775 1RD781 - RD783 1RD791 - RD792 1RE001 1RG001 - RG009 1RG091 3RG095 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 18 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 19 GroupVariable Number 1RG101 - RG104 3RG121 - RG126 1RG141 - RG142 3RG161 - RG164 1RG171 - RG174 1RG191 - RG193 1RG211 - RG213 3RG221 - RG222 1RH101 - RH102 1RH111 - RH112 1RH121 - RH122 5RS001 - RS002 5RS201 5RS211 - RS212 5RS221 - RS222 5RS231 - RS241 5RS251 - RS259 5RS263 5RS265 - RS268 5RS271 - RS276 5RS291 - RS292 5RS301 - RS306 5RS311 - RS320 5RS331 - RS333 5RS341 - RS342 5RS699 5RS701 - RS703 5RS711 - RS713 6RS721 - RS722 5RS731 - RS732 5RS741 - RS743 5RS751 - RS752 5RS761 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 19 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 20 GroupVariable Number 6RS762 5RS771 5RS781 - RS782 5RS786 2. Spares Affected None. B. Concurrent Requirements None. C. Reason Accomplishment of the inspections shown in this service bulletin will ensure the structural integrity of the upper chords of the upper deck floor beams. Cracks in these chords that are not found and repaired could become large and cause the floor beam to become severed. This can lead to large deflection or deformation of the floor and of the body skin, frames, and stringers. This deflection or deformation could result in damage to wire bundles and unintended inputs to the flight control cables which could affect airplane controllability. Multiple adjacent severed floor beams could result in rapid decompression of the airplane. Flight critical wire bundles and control cables are routed through cutouts in the upper deck floor beams. Upper deck floor beam upper chord cracks were found on Boeing's 747-SR Fatigue Test airplane, which accumulated 20,000 full pressure flight-cycles and an additional 20,000 test cycles. Numerous upper chord cracks were also reported by several operators accomplishing the inspections shown in Boeing Service Bulletin 747-53A2349, "Fuselage - Inspections Based on Fatigue Test Results." A structural reassessment of the 747 airplane was conducted under the requirements of Federal Aviation Administration (FAA) Advisory Circular 91-56, in accordance with Federal Aviation Regulation (FAR) 25.571 as amended in 1978, to ensure safe operation of 747 airplanes throughout their operational life. From this requirement, the Section 41 upper deck floor beam upper chords were determined to be significant, in that they are critical to airplane structural integrity. Therefore, a flight safety inspection program which will continue throughout the operational life of the airplane is specified in this service bulletin. The inspections shown in this service bulletin were previously included in Revision 1 of Boeing Service Bulletin 747-53A2349, "Fuselage - Inspections Based on Fatigue Test Results." Upper chord HFEC inspections are required by FAA Airworthiness Directive (AD) AD 2005-20-29. The initial inspection compliance time to start High Frequency Eddy Current (HFEC) inspections of upper deck floor beam upper chords that were previously in Service Bulletin 747-53A2349, Revision 1 was reduced for the original issue of this service bulletin because of the critical nature of the header floor beams that reinforce the upper deck floor stairway cutouts. The Area 3 inspections were included to address a location where cracks were found on Boeing's 747SR Fatigue Test airplane, but was not included in Service Bulletin 747-53A2349. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 20 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 21 The initial inspection compliance times have been further reduced in Revision 1 of this service bulletin to align with the initial inspection compliance times for Supplemental Structural Inspection Document (SSID) D6-35022 requirements for the same structure. Boeing Service Related Problem (SRP) 747-SRP-53-0122 is related to this service bulletin. Subsequent to the original issue of this service bulletin, Boeing has determined that upper deck floor beam upper chords are susceptible to Widespread Fatigue Damage (WFD). Ongoing inspection of this structure is not sufficient to maintain an acceptable level of safety. Therefore, Boeing plans to issue another service bulletin that will recommend replacement of the upper chords. Accomplishment of the upper chord replacement service bulletin will terminate the inspection requirements of this service bulletin. For more information on WFD, refer to Boeing Service Letter 747-SL-53-088A. Revision 1 is sent to reduce initial inspection compliance times, add replacement requirements for upper deck floor beam upper chords, and add inspection requirements at all permanent fastener locations common to the affected upper deck floor beam upper and lower chords. D. Description Get access from above or below to the upper chord of the upper deck floor beams from STA 380 aft. If access is gained from above, do open-hole HFEC inspections for cracks at floor panel attachment fastener holes in the upper chords. If access is gained from below, modify the clipnuts for the floor panel attachment fasteners in accordance with this service bulletin and do surface HFEC inspections for cracks of the forward and aft horizontal flanges of the upper chord. If any crack is found, do a repair as shown in this service bulletin. If no cracks are found, do the inspection again at the time shown in Paragraph 1.E., Compliance. Get access to the upper and lower chord of the upper deck floor beams at the location in accordance with this service bulletin. Do surface HFEC inspection for cracks in the upper and lower chords of the upper deck floor beams at permanent fastener locations. If any crack is found, contact Boeing for repair instructions, and do the repair. If no cracks are found, do the inspection again at the time in accordance with Paragraph 1.E., Compliance . For areas repaired as shown in this service bulletin, start to do repeat inspections at repaired locations as shown in this service bulletin at the times shown in Paragraph 1.E., Compliance. For any locations that have a repair that is different from those shown in this service bulletin, contact Boeing for an after-repair inspection plan. For the purposes of this service bulletin, do not count flight-cycles with a cabin pressure differential of 2.0 psi or less. However, any flight-cycle with momentary spikes in cabin pressure differential above 2.0 psi must be included as a full-pressure flight-cycle. Cabin pressure records must be maintained for each airplane. Fleet averaging of cabin pressure is not allowed. Revision 1 - More work is necessary on the airplane(s) inspected in accordance with the original issue of this service bulletin. Inspection of permanent fastener locations in Area 1 and Area 2 have been added. Also, initial inspection compliance times have been reduced for all inspection areas. Refer to Paragraph 1.E., Compliance, for details. The work in this service bulletin is done in the maintenance zone(s) given below. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 21 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 22 Group 1: Affected Maintenance Zones ZoneModel 221, 222, 223, 224, 225, 226, 233, 234747-100, 747-100B, 747-200B, 747SR Group 1, 3: Affected Maintenance Zones ZoneModel 221, 222, 223, 224, 225, 226747SP Group 2: Affected Maintenance Zones ZoneModel 221, 222, 223, 224, 225, 226, 233, 234747-100, 747-200B, 747SR Group 3-4, 6: Affected Maintenance Zones ZoneModel 221, 222, 223, 224, 225, 226, 233, 234747-200B Group 5: Affected Maintenance Zones ZoneModel 221, 222, 223, 224, 225, 226, 233, 234747-100B SUD, 747-200B Group 5-6: Affected Maintenance Zones ZoneModel 221, 222, 223, 224, 225, 226747-300 E. Compliance Federal Aviation Administration (FAA) Airworthiness Directives AD 2005-20-29 and AD 2004-07-22 R1 are related to this service bulletin. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 22 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 23 Group 1-4; Group 5, Configuration 1: Table 1: Compliance Times for Upper Deck Floor Beam Upper Chord Initial and Repeat Inspections in Area 1 Repeat Inter- val (Not to Ex- ceed) Compliance Time (Whichever Occurs Later)ActionCondition -Within 2,000 flight cycles after the Revision 1 date of this ser- vice bulletin. (c) (d) Before 20,000 total flight cy- cles. Do open hole or surface HFEC inspection for cracks at the floor panel attachment fastener holes in Area 1 in accor- dance with Paragraph 3.B., Work Instructions, Part 3 or Part 4. Airplanes not previ- ously inspected in accordance with this service bul- letin. -Before further flight.Repair the floor beam upper chord in accor- dance with Paragraph 3.B., Work Instructions, Part 6. Any crack found at a floor panel at- tachment fastener hole. 750 flight cy- cles if surface HFEC inspec- tion method was used. 3,000 flight cy- cles if open hole HFEC in- spection method was used. Within 750 flight cycles if surface HFEC inspec- tion method was used, or within 3,000 flight cy- cles if open hole inspection method was used. Repeat open hole or surface HFEC inspec- tion for cracks at floor panel attachment fasten- er holes in Area 1 in ac- cordance with Para- graph 3.B., Work Instruc- tions, Part 3 or Part 4. Airplanes previous- ly inspected in ac- cordance with this service bulletin. or No crack found in the floor panel at- tachment fastener holes. -Before further flight.As an option, do the hole modification proce- dure in accordance with FIGURE 4. -Before further flight.As an option, do one of the repair procedures as a hole modification in accordance with Para- graph 3.B., Work Instruc- tions, Part 6. -Refer to Table 8 in Paragraph 1.E., Compliance.Refer to Table 8 in Paragraph 1.E., Compli- ance. Location(s) modi- fied or repaired in accordance with FIGURE 4 or Paragraph 3.B., Work Instructions, Part 6. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 23 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 24 Group 1-4; Group 5, Configuration 1: Table 1: Compliance Times for Upper Deck Floor Beam Upper Chord Initial and Repeat Inspections in Area 1 Repeat Inter- val (Not to Ex- ceed) Compliance Time (Whichever Occurs Later)ActionCondition -Within 3,000 flight cycles of the last SSID inspection. (a) Within 2,000 flight cycles af- ter the Revi- sion 1 date of this service bulletin. Before 20,000 total flight cy- cles. Do surface HFEC inspec- tions for cracks in the upper and lower chords of the upper deck floor beams at permanent fastener locations in Area 1 in accordance with Paragraph 3.B., Work Instructions, Part 5. (b) All airplanes. -Before further flight.Contact Boeing for re- pair instructions, and do the repair. Any crack found at a permanent fas- tener location. 3,000 flight cy- cles. Within 3,000 flight cycles after the last inspection.Repeat surface HFEC inspections for cracks at permanent fastener loca- tions in accordance with Paragraph 3.B., Work Instructions, Part 5. (b) No crack found at permanent fasten- er locations. (a) Applicable only to airplanes that have previously had the upper deck floor beam upper chords inspected in accordance with Supplemental Structural Inspection Document (SSID) D6-35022. (b) For purposes of this service bulletin, "permanent" fastener locations are defined as all fastener locations, except floor panel attachment fastener locations. (c) Supplemental Structural Inspection Document (SSID) D6-35022, Revision G requires inspections prior to 20,000 total flight-cycles. (d) FAA AD 2005-20-09 requires inspections prior to 22,000 total flight-cycles. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 24 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 25 Group 5, Configuration 2: Table 2: Compliance Times for Upper Deck Floor Beam Upper Chord Initial and Repeat Inspections in Area 1 Repeat Inter- val (Not to Ex- ceed) Compliance Time (Whichever Occurs Later)ActionCondition -Within 2,000 flight cycles after the Revision 1 date of this ser- vice bulletin. (d) (e) Before 20,000 total flight cy- cles. Do open hole or surface HFEC inspection for cracks at the floor panel attachment fastener holes in Area 1 in accor- dance with Paragraph 3.B., Work Instructions, Part 3 or Part 4. (c) Airplanes not previ- ously inspected in accordance with this service bul- letin. -Within 2,000 flight cycles af- ter the Revi- sion 1 date of this service bulletin. Within 10,000 flight cycles af- ter the rein- forcement of the STA 860 and STA 980 floor beams was done in accordance with Service Bulletin 747- 53-2327. Before 20,000 total flight cy- cles. Do open hole HFEC in- spection for cracks at floor panel attachment holes at STA 860 and STA 980 floor beam up- per chords in accor- dance with Paragraph 3.B., Work Instructions, Part 3. -Before further flight.Repair the floor beam upper chord in accor- dance with Paragraph 3.B., Work Instructions, Part 6. Any crack found at a floor panel at- tachment fastener hole. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 25 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 26 Group 5, Configuration 2: Table 2: Compliance Times for Upper Deck Floor Beam Upper Chord Initial and Repeat Inspections in Area 1 Repeat Inter- val (Not to Ex- ceed) Compliance Time (Whichever Occurs Later)ActionCondition 750 flight cy- cles if surface HFEC inspec- tion method was used. 3,000 flight cy- cles if open hole HFEC in- spection method was used. Within 750 flight cycles if surface HFEC inspec- tion method was used, or within 3,000 flight cy- cles if open hole inspection method was used. Repeat open hole or surface HFEC inspec- tion for cracks at floor panel attachment fasten- er holes in Area 1 in ac- cordance with Para- graph 3.B., Work Instruc- tions, Part 3 or Part 4. Airplanes previous- ly inspected in ac- cordance with this service bulletin. or No crack found in the floor panel at- tachment fastener holes. -Before further flight.As an option, do the hole modification proce- dure in accordance with FIGURE 4. -Before further flight.As an option, do one of the repair procedures as a hole modification in accordance with Para- graph 3.B., Work Instruc- tions, Part 6. -Refer to Table 8 in Paragraph 1.E., Compliance.Refer to Table 8 in Paragraph 1.E., Compli- ance. Location(s) modi- fied or repaired in accordance with FIGURE 4 or Paragraph 3.B., Work Instructions, Part 6. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 26 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 27 Group 5, Configuration 2: Table 2: Compliance Times for Upper Deck Floor Beam Upper Chord Initial and Repeat Inspections in Area 1 Repeat Inter- val (Not to Ex- ceed) Compliance Time (Whichever Occurs Later)ActionCondition -Within 3,000 flight cycles of the last SSID inspection. (a) Within 2,000 flight cycles af- ter the Revi- sion 1 date of this service bulletin. Before 20,000 total flight cy- cles. Do surface HFEC inspec- tions for cracks in the upper and lower chords of the upper deck floor beams at permanent fastener locations in Area 1 in accordance with Paragraph 3.B., Work Instructions, Part 5. (b) (c) All airplanes. -Within 3,000 flight cycles of the last SSID inspection. (a) Within 10,000 flight cycles af- ter the rein- forcement of the STA 860 and STA 980 floor beams was done in accordance with Service Bulletin 747- 53-2327, or within 2,000 flight cycles af- ter the Revi- sion 1 date of this service bulletin, whichever is later. Before 20,000 total flight cy- cles. Do surface HFEC inspec- tions for cracks in the upper and lower chords of the upper deck floor beams at permanent fastener locations at STA 860 and STA 980 in accordance with Paragraph 3.B., Work Instructions, Part 5. (b) -Before further flight.Contact Boeing for re- pair instructions, and do the repair. Any crack found at a permanent fas- tener location. 3,000 flight cy- cles. Within 3,000 flight cycles after the last inspection.Repeat surface HFEC inspections for cracks at permanent fastener loca- tions in accordance with Paragraph 3.B., Work Instructions, Part 5. (b) No crack found at permanent fasten- er locations. (a) Applicable only to airplanes that have previously had the upper deck floor beam upper chords inspected in accordance with Supplemental Structural Inspection Document (SSID) Document D6-35022. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 27 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 28 Group 5, Configuration 2: Table 2: Compliance Times for Upper Deck Floor Beam Upper Chord Initial and Repeat Inspections in Area 1 Repeat Inter- val (Not to Ex- ceed) Compliance Time (Whichever Occurs Later)ActionCondition (b) For purposes of this service bulletin, "permanent" fastener locations are defined as all fastener locations, except floor panel attachment fastener locations. (c) Except STA 860 and STA 980. (d) Supplemental Structural Inspection Document (SSID) D6-35022, Revision G requires inspections prior to 20,000 total flight-cycles. (e) FAA AD 2005-20-09 requires inspections prior to 22,000 total flight-cycles. Group 6: Table 3: Compliance Times for Upper Deck Floor Beam Upper Chord Initial and Repeat Inspections in Area 1 Repeat Inter- val (Not to Ex- ceed) Compliance Time (Whichever Occurs Later)ActionCondition -Within 2,000 flight cycles af- ter the Revi- sion 1 date of this service bulletin. Within 10,000 flight cycles af- ter modification to Boeing Spe- cial Freighter. Before 20,000 total flight cy- cles. Do open hole or surface HFEC inspection for cracks at the floor panel attachment fastener holes at STA 440, 500, and 520 in accordance with Paragraph 3.B., Work Instructions, Part 3 or Part 4. Airplanes not previ- ously inspected in accordance with this service bul- letin. -Before further flight.Repair the floor beam upper chord in accor- dance with Paragraph 3.B., Work Instructions, Part 6. Any crack found at a floor panel at- tachment fastener hole. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 28 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 29 Group 6: Table 3: Compliance Times for Upper Deck Floor Beam Upper Chord Initial and Repeat Inspections in Area 1 Repeat Inter- val (Not to Ex- ceed) Compliance Time (Whichever Occurs Later)ActionCondition 750 flight cy- cles if surface HFEC inspec- tion method was used. 3,000 flight cy- cles if open hole HFEC in- spection method was used. Within 750 flight cycles if surface HFEC inspec- tion method was used, or within 3,000 flight cy- cles if open hole inspection method was used. Repeat open hole or surface HFEC inspec- tion for cracks at floor panel attachment fasten- er holes at STA 440, 500 and 520 in accor- dance with Paragraph 3.B., Work Instructions, Part 3 or Part 4. Airplanes previous- ly inspected in ac- cordance with this service bulletin. or No crack found in the floor panel at- tachment fastener holes. -Before further flight.As an option, do the hole modification proce- dure in accordance with FIGURE 4. -Before further flight.As an option, do one of the repair procedures as a hole modification in accordance with Para- graph 3.B., Work Instruc- tions, Part 6. -Refer to Table 8 in Paragraph 1.E., Compliance.Refer to Table 8 in Paragraph 1.E., Compli- ance. Location(s) modi- fied or repaired in accordance with FIGURE 4 or Paragraph 3.B., Work Instructions, Part 6. -Within 2,000 flight cycles af- ter the Revi- sion 1 date of this service bulletin. Within 10,000 flight cycles af- ter modification to Boeing Spe- cial Freighter. Before 20,000 total flight cy- cles. Do surface HFEC inspec- tions for cracks in the upper and lower chords of the upper deck floor beams at permanent fastener locations at STA 440, 500 and 520 in accordance with Paragraph 3.B., Work Instructions, Part 5. (a) All airplanes. -Before further flight.Contact Boeing for re- pair instructions, and do the repair. Any crack found at a permanent fas- tener location. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 29 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 30 Group 6: Table 3: Compliance Times for Upper Deck Floor Beam Upper Chord Initial and Repeat Inspections in Area 1 Repeat Inter- val (Not to Ex- ceed) Compliance Time (Whichever Occurs Later)ActionCondition 3,000 flight cy- cles. Within 3,000 flight cycles after the last inspection.Repeat surface HFEC inspections for cracks at permanent fastener loca- tions in accordance with Paragraph 3.B., Work Instructions, Part 5. (a) No crack found at permanent fasten- er locations. (a) For purposes of this service bulletin, "permanent" fastener locations are defined as all fastener locations, except floor panel attachment fastener locations. Group 1-3, 5: Table 4: Compliance Times for Upper Deck Floor Beam Upper Chord Initial and Repeat Inspections in Area 2 Repeat Inter- val (Not to Ex- ceed) Compliance Time (Whichever Occurs Later)ActionCondition -Within 2,000 flight cycles of the last SSID inspection, if surface HFEC was used in that inspection. Within 6,000 flight cycles of the last SSID inspection, if open hole HFEC was used in that in- spection. (a) Within 2,000 flight cycles af- ter the Revi- sion 1 date of this service bulletin. (d) (e) Before 20,000 total flight cy- cles. Do open hole or surface HFEC inspection for cracks at the floor panel attachment fastener holes in Area 2 in accor- dance with Paragraph 3.B., Work Instructions, Part 3 or Part 4. All airplanes not previously inspect- ed in accordance with this service bulletin. -Before further flight.Repair the floor beam upper chord in accor- dance with Paragraph 3.B., Work Instructions, Part 6. Any crack found at a floor panel at- tachment fastener hole. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 30 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 31 Group 1-3, 5: Table 4: Compliance Times for Upper Deck Floor Beam Upper Chord Initial and Repeat Inspections in Area 2 Repeat Inter- val (Not to Ex- ceed) Compliance Time (Whichever Occurs Later)ActionCondition 2,000 flight cy- cles if surface HFEC inspec- tion method was used. 6,000 flight cy- cles if open hole HFEC in- spection method was used. Within 2,000 flight cycles if surface HFEC method was used, or within 6,000 flight cycles if open hole HFEC method was used. Repeat open hole or surface HFEC inspec- tion for cracks at floor panel attachment fasten- er holes in Area 2 in ac- cordance with Para- graph 3.B., Work Instruc- tions, Part 3 or Part 4. Airplanes previous- ly inspected in ac- cordance with this service bulletin. or No crack found in the floor panel at- tachment fastener holes. -Before further flight.As an option, do the hole modification proce- dure in accordance with FIGURE 4. -Before further flight.As an option, do one of the repair procedures as a hole modification in accordance with Para- graph 3.B., Work Instruc- tions, Part 6. -Refer to Table 9 in Paragraph 1.E., Compliance.Refer to Table 9 in Paragraph 1.E., Compli- ance. Location(s) modi- fied or repaired in accordance with FIGURE 4 or Paragraph 3.B., Work Instructions, Part 6. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 31 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 32 Group 1-3, 5: Table 4: Compliance Times for Upper Deck Floor Beam Upper Chord Initial and Repeat Inspections in Area 2 Repeat Inter- val (Not to Ex- ceed) Compliance Time (Whichever Occurs Later)ActionCondition -Within 2,000 flight cycles of the last SSID inspection, if surface HFEC was used in that inspection. Within 6,000 flight cycles of the last SSID inspection, if open hole HFEC was used in that in- spection. (a) Within 2,000 flight cycles af- ter the Revi- sion 1 date of this service bulletin. Before 20,000 total flight cy- cles. Do surface HFEC inspec- tions for cracks in the upper chords of the up- per deck floor beams at permanent fastener loca- tions in Area 2 in accor- dance with Paragraph 3.B., Work Instructions, Part 5. (b) All airplanes. -Before further flight.Contact Boeing for re- pair instructions, and do the repair. Any crack found at a permanent fas- tener location. 3,000 flight cy- cles. Within 3,000 flight cycles after the last inspection.Repeat surface HFEC inspections for cracks at permanent fastener loca- tions where the upper chord flange is hidden in accordance with Para- graph 3.B., Work Instruc- tions, Part 5. (b) (c) No crack found at permanent fasten- er locations. 6,000 flight cy- cles. Within 6,000 flight cycles after the last inspection.Repeat surface HFEC inspections for cracks at permanent fastener loca- tions where the upper chord flange is not hid- den in accordance with Paragraph 3.B., Work Instructions, Part 5. (b) (c) No crack found at permanent fasten- er locations. (a) Applicable only to airplanes that have previously had the upper deck floor beam upper chords inspected in accordance with Supplemental Structural Inspection Document (SSID) Document D6-35022. (b) For purposes of this service bulletin, "permanent" fastener locations are defined as all fastener locations, except floor panel attachment fastener locations. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 32 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 33 Group 1-3, 5: Table 4: Compliance Times for Upper Deck Floor Beam Upper Chord Initial and Repeat Inspections in Area 2 Repeat Inter- val (Not to Ex- ceed) Compliance Time (Whichever Occurs Later)ActionCondition (c) A "hidden" location is defined as any inspection location where surface HFEC cannot be performed directly on the surface of the upper chord flange around the fastener. Instead, the edge of the upper chord flange is inspected and a strap or angle that covers the upper chord flange is inspected. A location that is "not hidden" is any permanent fastener inspection location where the surface HFEC can be performed directly on the surface of the upper chord flange around the fastener. (d) Supplemental Structural Inspection Document (SSID) D6-35022, Revision G requires inspections prior to 20,000 total flight-cycles. (e) FAA AD 2005-20-09 requires inspections prior to 28,000 total flight-cycles. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 33 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 34 Group 4: Table 5: Compliance Times for Upper Deck Floor Beam Upper Chord Initial and Repeat Inspections in Area 2 Repeat Inter- val (Not to Ex- ceed) Compliance Time (Whichever Occurs Later)ActionCondition -Within 2,000 flight cycles of the last SSID inspection, if surface HFEC was used in that inspection. Within 6,000 flight cycles of the last SSID inspection, if open hole HFEC was used in that in- spection. (a) Within 2,000 flight cycles af- ter the Revi- sion 1 date of this service bulletin. (e) (f) Before 20,000 total flight cy- cles. Do open hole or surface HFEC inspection for cracks at the floor panel attachment fastener holes in Area 2 in accor- dance with Paragraph 3.B., Work Instructions, Part 3 or Part 4. (d) All airplanes not previously inspect- ed in accordance with this service bulletin. -Within 2,000 flight cycles of the last SSID inspection, if surface HFEC was used in that inspection. Within 6,000 flight cycles of the last SSID inspection, if open hole HFEC was used in that in- spection. (a) Within 10,000 flight cycles af- ter modification to Boeing Spe- cial Freighter, or within 2,000 flight cycles af- ter the Revi- sion 1 date of this service bulletin, whichever is later. Before 20,000 total flight cy- cles. Do open hole or surface HFEC inspection for cracks at the floor panel attachment fastener holes at STA 440 in ac- cordance with Para- graph 3.B., Work Instruc- tions, Part 3 or Part 4. -Before further flight.Repair the floor beam upper chord in accor- dance with Paragraph 3.B., Work Instructions, Part 6. Any crack found at a floor panel at- tachment fastener hole. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 34 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 35 Group 4: Table 5: Compliance Times for Upper Deck Floor Beam Upper Chord Initial and Repeat Inspections in Area 2 Repeat Inter- val (Not to Ex- ceed) Compliance Time (Whichever Occurs Later)ActionCondition 2,000 flight cy- cles if surface HFEC inspec- tion method was used. 6,000 flight cy- cles if open hole HFEC in- spection method was used. Within 2,000 flight cycles if surface HFEC method was used, or within 6,000 flight cycles if open hole HFEC method was used. Repeat open hole or surface HFEC inspec- tion for cracks at floor panel attachment fasten- er holes in Area 2 in ac- cordance with Para- graph 3.B., Work Instruc- tions, Part 3 or Part 4. Airplanes previous- ly inspected in ac- cordance with this service bulletin. or No crack found in the floor panel at- tachment fastener holes. -Before further flight.As an option, do the hole modification proce- dure in accordance with FIGURE 4. -Before further flight.As an option, do one of the repair procedures as a hole modification in accordance with Para- graph 3.B., Work Instruc- tions, Part 6. -Refer to Table 9 in Paragraph 1.E., Compliance.Refer to Table 9 in Paragraph 1.E., Compli- ance. Location(s) modi- fied or repaired in accordance with FIGURE 4 or Paragraph 3.B., Work Instructions, Part 6. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 35 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 36 Group 4: Table 5: Compliance Times for Upper Deck Floor Beam Upper Chord Initial and Repeat Inspections in Area 2 Repeat Inter- val (Not to Ex- ceed) Compliance Time (Whichever Occurs Later)ActionCondition -Within 2,000 flight cycles of the last SSID inspection, if surface HFEC was used in that inspection. Within 6,000 flight cycles of the last SSID inspection, if open hole HFEC was used in that in- spection. (a) Within 6,000 flight cycles af- ter the Revi- sion 1 date of this service bulletin. Before 20,000 total flight cy- cles. Do surface HFEC inspec- tions for cracks in the upper chords of the up- per deck floor beams at permanent fastener loca- tions in Area 2 in accor- dance with Paragraph 3.B., Work Instructions, Part 5. (b) (d) All airplanes. -Within 2,000 flight cycles of the last SSID inspection, if surface HFEC was used in that inspection. Within 6,000 flight cycles of the last SSID inspection, if open hole HFEC was used in that in- spection. (a) Within 10,000 flight cycles af- ter modification to Boeing Spe- cial Freighter, or within 2,000 flight cycles af- ter the Revi- sion 1 date of this service bulletin, whichever is later. Before 20,000 total flight cy- cles. Do surface HFEC inspec- tions for cracks in the upper chords of the up- per deck floor beams at permanent fastener at STA 440 in accordance with Paragraph 3.B., Work Instructions, Part 5. (b) -Before further flight.Contact Boeing for re- pair instructions, and do the repair. Any crack found at a permanent fas- tener location. 3,000 flight cy- cles. Within 3,000 flight cycles after the last inspection.Repeat surface HFEC inspections for cracks at permanent fastener loca- tions where the upper chord flange is hidden in accordance with Para- graph 3.B., Work Instruc- tions, Part 5. (b) (c) No crack found at permanent fasten- er locations. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 36 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 37 Group 4: Table 5: Compliance Times for Upper Deck Floor Beam Upper Chord Initial and Repeat Inspections in Area 2 Repeat Inter- val (Not to Ex- ceed) Compliance Time (Whichever Occurs Later)ActionCondition 6,000 flight cy- cles. Within 6,000 flight cycles after the last inspection.Repeat surface HFEC inspections for cracks at permanent fastener loca- tions where the upper chord flange is not hid- den in accordance with Paragraph 3.B., Work Instructions, Part 5. (b) (c) No crack found at permanent fasten- er locations. (a) Applicable only to airplanes that have previously had the upper deck floor beam upper chords inspected in accordance with Supplemental Structural Inspection Document (SSID) Document D6-35022. (b) For purposes of this service bulletin, "permanent" fastener locations are defined as all fastener locations, except floor panel attachment fastener locations. (c) A "hidden" location is defined as any inspection location where surface HFEC cannot be performed directly on the surface of the upper chord flange around the fastener. Instead, the edge of the upper chord flange is inspected and a strap or angle that covers the upper chord flange is inspected. A location that is "not hidden" is any permanent fastener inspection location where the surface HFEC can be performed directly on the surface of the upper chord flange around the fastener. (d) Except STA 440. (e) Supplemental Structural Inspection Document (SSID) D6-35022, Revision G requires inspections prior to 20,000 total flight-cycles. (f) FAA AD 2005-20-09 requires inspections prior to 28,000 total flight-cycles. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 37 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 38 Group 6: Table 6: Compliance Times for Upper Deck Floor Beam Upper Chord Initial and Repeat Inspections in Area 2 Repeat Inter- val (Not to Ex- ceed) Compliance Time (Whichever Occurs Later)ActionCondition -Within 2,000 flight cycles of the last SSID inspection, if surface HFEC was used in that inspection. Within 6,000 flight cycles of the last SSID inspection, if open hole HFEC was used in that in- spection. (a) Within 2,000 flight cycles af- ter the Revi- sion 1 date of this service bulletin. (e) (f) Before 20,000 total flight cy- cles. Do open hole or surface HFEC inspection for cracks at the floor panel attachment fastener holes in Area 2 in accor- dance with Paragraph 3.B., Work Instructions, Part 3 or Part 4. (d) All airplanes not previously inspect- ed in accordance with this service bulletin. -Within 2,000 flight cycles of the last SSID inspection, if surface HFEC was used in that inspection. Within 6,000 flight cycles of the last SSID inspection, if open hole HFEC was used in that in- spection. (a) Within 10,000 flight cycles af- ter modification to Boeing Spe- cial Freighter, or within 2,000 flight cycles af- ter the Revi- sion 1 date of this service bulletin, whichever is later. Before 20,000 total flight cy- cles. Do open hole or surface HFEC inspection for cracks at the floor panel attachment fastener holes at STA 460 and 480 in accordance with Paragraph 3.B., Work Instructions, Part 3 or Part 4. -Before further flight.Repair the floor beam upper chord in accor- dance with Paragraph 3.B., Work Instructions, Part 6. Any crack found at a floor panel at- tachment fastener hole. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 38 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 39 Group 6: Table 6: Compliance Times for Upper Deck Floor Beam Upper Chord Initial and Repeat Inspections in Area 2 Repeat Inter- val (Not to Ex- ceed) Compliance Time (Whichever Occurs Later)ActionCondition 2,000 flight cy- cles if surface HFEC inspec- tion method was used. 6,000 flight cy- cles if open hole HFEC in- spection method was used. Within 2,000 flight cycles if surface HFEC method was used, or within 6,000 flight cycles if open hole HFEC method was used. Repeat open hole or surface HFEC inspec- tion for cracks at floor panel attachment fasten- er holes in Area 2 in ac- cordance with Para- graph 3.B., Work Instruc- tions, Part 3 or Part 4. Airplanes previous- ly inspected in ac- cordance with this service bulletin. or No crack found in the floor panel at- tachment fastener holes. -Before further flight.As an option, do the hole modification proce- dure in accordance with FIGURE 4. -Before further flight.As an option, do one of the repair procedures as a hole modification in accordance with Para- graph 3.B., Work Instruc- tions, Part 6. -Refer to Table 9 in Paragraph 1.E., Compliance.Refer to Table 9 in Paragraph 1.E., Compli- ance. Location(s) modi- fied or repaired in accordance with FIGURE 4 or Paragraph 3.B., Work Instructions, Part 6. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 39 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 40 Group 6: Table 6: Compliance Times for Upper Deck Floor Beam Upper Chord Initial and Repeat Inspections in Area 2 Repeat Inter- val (Not to Ex- ceed) Compliance Time (Whichever Occurs Later)ActionCondition -Within 2,000 flight cycles of the last SSID inspection, if surface HFEC was used in that inspection. Within 6,000 flight cycles of the last SSID inspection, if open hole HFEC was used in that in- spection. (a) Within 2,000 flight cycles af- ter the Revi- sion 1 date of this service bulletin. Before 20,000 total flight cy- cles. Do surface HFEC inspec- tions for cracks in the upper chords of the up- per deck floor beams at permanent fastener loca- tions in Area 2 in accor- dance with Paragraph 3.B., Work Instructions, Part 5. (b) (d) All airplanes. -Within 2,000 flight cycles of the last SSID inspection, if surface HFEC was used in that inspection. Within 6,000 flight cycles of the last SSID inspection, if open hole HFEC was used in that in- spection. (a) Within 10,000 flight cycles af- ter modification to Boeing Spe- cial Freighter, or within 2,000 flight cycles af- ter the Revi- sion 1 date of this service bulletin, whichever is later. Before 20,000 total flight cy- cles. Do surface HFEC inspec- tions for cracks in the upper chords of the up- per deck floor beams at permanent fastener at STA 460 and 480 in ac- cordance with Para- graph 3.B., Work Instruc- tions, Part 5. (b) -Before further flight.Contact Boeing for re- pair instructions, and do the repair. Any crack found at a permanent fas- tener location. 3,000 flight cy- cles. Within 3,000 flight cycles after the last inspection.Repeat surface HFEC inspections for cracks at permanent fastener loca- tions where the upper chord flange is hidden in accordance with Para- graph 3.B., Work Instruc- tions, Part 5. (b) (c) No crack found at permanent fasten- er locations. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 40 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 41 Group 6: Table 6: Compliance Times for Upper Deck Floor Beam Upper Chord Initial and Repeat Inspections in Area 2 Repeat Inter- val (Not to Ex- ceed) Compliance Time (Whichever Occurs Later)ActionCondition 6,000 flight cy- cles. Within 6,000 flight cycles after the last inspection.Repeat surface HFEC inspections for cracks at permanent fastener loca- tions where the upper chord flange is not hid- den in accordance with Paragraph 3.B., Work Instructions, Part 5. (b) (c) No crack found at permanent fasten- er locations. (a) Applicable only to airplanes that have previously had the upper deck floor beam upper chords inspected in accordance with Supplemental Structural Inspection Document (SSID) Document D6-35022. (b) For purposes of this service bulletin, "permanent" fastener locations are defined as all fastener locations, except floor panel attachment fastener locations. (c) A "hidden" location is defined as any inspection location where surface HFEC cannot be performed directly on the surface of the upper chord flange around the fastener. Instead, the edge of the upper chord flange is inspected and a strap or angle that covers the upper chord flange is inspected. A location that is "not hidden" is any permanent fastener inspection location where the surface HFEC can be performed directly on the surface of the upper chord flange around the fastener. (d) Except STA 460 and 480. (e) Supplemental Structural Inspection Document (SSID) D6-35022, Revision G requires inspections prior to 20,000 total flight-cycles. (f) FAA AD 2005-20-09 requires inspections prior to 28,000 total flight-cycles. Group 1-2: Table 7: Compliance Times for Initial and Repeat Inspections Station 440 Upper Deck Floor Beam Upper Chord and Gusset in Area 3 Repeat Inter- val (Not to Ex- ceed) Compliance Time (Whichever Occurs Later)ActionCondition -Within 2,000 flight cycles after the Revision 1 date of this ser- vice bulletin. (a) (b) Before 20,000 total flight cy- cles. Do open hole HFEC in- spections for cracks in the upper chord and gusset of the upper deck floor beam at Station 440 in Area 3 in accor- dance with Paragraph 3.B., Work Instructions, Part 7. All airplanes. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 41 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 42 Group 1-2: Table 7: Compliance Times for Initial and Repeat Inspections Station 440 Upper Deck Floor Beam Upper Chord and Gusset in Area 3 Repeat Inter- val (Not to Ex- ceed) Compliance Time (Whichever Occurs Later)ActionCondition 3,000 flight cy- cles. Within 3,000 flight cycles after the last inspection.Repeat open hole HFEC inspections for cracks in the upper chord and gusset of the upper deck floor beam at Station 440 in Area 3 in accor- dance with Paragraph 3.B., Work Instructions, Part 7. No crack found. -Before further flight.Contact Boeing for re- pair instructions, and do the repair. Crack found. (a) Supplemental Structural Inspection Document (SSID) D6-35022, Revision G requires inspections prior to 20,000 total flight-cycles. (b) FAA AD 2005-20-09 requires inspections prior to 22,000 total flight-cycles. Table 8: Compliance Times for Inspection of Location(s) Repaired or Modified in Area 1 (After-Repair Inspections) Repeat Interval (Not to Exceed) Compliance TimeActionCondition 750 flight cycles if surface HFEC was used; 3,000 flight cy- cles if open hole HFEC was used. WIthin 15,000 flight cycles after the hole oversize was done. Do open hole or sur- face HFEC inspection for cracks in accor- dance with Paragraph 3.B., Work Instruc- tions Part 3 or Part 4. Location(s) modified in accordance with FIGURE 4 where edge margin after modification is 2.0D or more. 750 flight cycles if surface HFEC was used; 3,000 flight cy- cles if open hole HFEC was used. WIthin 10,000 flight cycles after the hole oversize was done. Do open hole or sur- face HFEC inspection for cracks in accor- dance with Paragraph 3.B., Work Instruc- tions Part 3 or Part 4. Location(s) modified in accordance with FIGURE 4 where edge margin after modification is 1.3D or more, but less than 2.0D. 750 flight cycles if surface HFEC was used; 3,000 flight cy- cles if open hole HFEC was used. Within 15,000 flight cycles after the repair was accomplished. Do open hole or sur- face HFEC inspection for cracks in accor- dance with Paragraph 3.B., Work Instruc- tions Part 3 or Part 4. Location(s) where repair #1 was done in accordance with Paragraph 3.B., PART 6 of this service bulletin. (a) Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 42 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 43 Table 8: Compliance Times for Inspection of Location(s) Repaired or Modified in Area 1 (After-Repair Inspections) Repeat Interval (Not to Exceed) Compliance TimeActionCondition 750 flight cycles if surface HFEC was used; 3,000 flight cy- cles if open hole HFEC was used. Within 10,000 flight cycles after the repair was accomplished. Do open hole or sur- face HFEC inspection for cracks in accor- dance with Paragraph 3.B., Work Instruc- tions Part 3 or Part 4. Location(s) where repair #2 was done in accordance with Paragraph 3.B., PART 6 of this service bulletin. (a) 3,000 flight cycles.Within 10,000 flight cycles after the repair was accomplished. Do an open hole HFEC inspection for cracks in accordance with Paragraph 3.B., Work Instructions Part 8. Location(s) where repair #3 was done in accordance with Paragraph 3.B., PART 6 of this service bulletin. (a) 3,000 flight cycles.Within 5,000 flight cy- cles after the repair was accomplished. Do open hole HFEC inspection for cracks in accordance with Paragraph 3.B., Work Instructions Part 3. Location(s) where repair #4 was done in accordance with Paragraph 3.B., PART 6 of this service bulletin. (a) 3,000 flight cycles.Within 5,000 flight cy- cles after the repair was accomplished. Do an open hole HFEC inspection for cracks in accordance with Paragraph 3.B., Work Instructions Part 8. Location(s) where repair #5 was done in accordance with Paragraph 3.B., PART 6 of this service bulletin. (a) 3,000 flight cycles.Within 10,000 flight cycles after the repair was accomplished. Do open hole and surface HFEC inspec- tions for cracks in ac- cordance with Para- graph 3.B., Work In- structions Part 8. Location(s) where repair #6, #7, #8, #9, #11 or #12 was done in accordance with Paragraph 3.B., PART 6 of this service bulletin. (a) -Before further flight.Contact Boeing for af- ter-repair inspection instructions and do the inspections at the compliance times specified by Boeing. Location(s) where repair #10 or #13 was done in accordance with Paragraph 3.B., PART 6 of this service bulletin. (a) -Before further flight.Contact Boeing for repair instructions, and do the repair. Any crack found in the repaired or modi- fied location(s). (a) Refer to Paragraph 3.B., Work Instructions, PART 6, Tables 1 and 2 for corresponding repair procedures. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 43 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 44 Table 9: Compliance Times for Inspection of Location(s) Repaired or Modified in Area 2 (After-Repair Inspections) Repeat Interval (Not to Exceed) Compliance TimeActionCondition 2,000 flight cycles if surface HFEC was used; 6,000 flight cy- cles if open hole HFEC was used. WIthin 15,000 flight cycles after the hole oversize was done. Do open hole or sur- face HFEC inspection for cracks in accor- dance with Paragraph 3.B., Work Instruc- tions Part 3 or Part 4. Location(s) modified in accordance with FIGURE 4 where edge margin after modification is 2.0D or more. 2,000 flight cycles if surface HFEC was used; 6,000 flight cy- cles if open hole HFEC was used. WIthin 10,000 flight cycles after the hole oversize was done. Do open hole or sur- face HFEC inspection for cracks in accor- dance with Paragraph 3.B., Work Instruc- tions Part 3 or Part 4. Location(s) modified in accordance with FIGURE 4 where edge margin after modification is 1.3D or more, but less than 2.0D. 2,000 flight cycles if surface HFEC was used; 6,000 flight cy- cles if open hole HFEC was used. Within 15,000 flight cycles after the repair was accomplished. Do open hole or sur- face HFEC inspection for cracks in accor- dance with Paragraph 3.B., Work Instruc- tions Part 3 or Part 4. Location(s) where repair #1 was done in accordance with Paragraph 3.B., PART 6 of this service bulletin. (a) 2,000 flight cycles if surface HFEC was used; 6,000 flight cy- cles if open hole HFEC was used. Within 10,000 flight cycles after the repair was accomplished. Do open hole or sur- face HFEC inspection for cracks in accor- dance with Paragraph 3.B., Work Instruc- tions Part 3 or Part 4. Location(s) where repair #2 was done in accordance with Paragraph 3.B., PART 6 of this service bulletin. (a) 3,000 flight cycles.Within 10,000 flight cycles after the repair was accomplished. Do an open hole HFEC inspection for cracks in accordance with Paragraph 3.B., Work Instructions Part 8. Location(s) where repair #3 was done in accordance with Paragraph 3.B., PART 6 of this service bulletin. (a) 3,000 flight cycles.Within 5,000 flight cy- cles after the repair was accomplished. Do open hole HFEC inspection for cracks in accordance with Paragraph 3.B., Work Instructions Part 3. Location(s) where repair #4 was done in accordance with Paragraph 3.B., PART 6 of this service bulletin. (a) 3,000 flight cycles.Within 5,000 flight cy- cles after the repair was accomplished. Do an open hole HFEC inspection for cracks in accordance with Paragraph 3.B., Work Instructions Part 8. Location(s) where repair #5 was done in accordance with Paragraph 3.B., PART 6 of this service bulletin. (a) Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 44 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 45 Table 9: Compliance Times for Inspection of Location(s) Repaired or Modified in Area 2 (After-Repair Inspections) Repeat Interval (Not to Exceed) Compliance TimeActionCondition 6,000 flight cycles.Within 10,000 flight cycles after the repair was accomplished. Do open hole and surface HFEC inspec- tions for cracks in ac- cordance with Para- graph 3.B., Work In- structions Part 8. Location(s) where repair #6, #7, #8, #9, #11 or #12 was done in accordance with Paragraph 3.B., PART 6 of this service bulletin. (a) -Before further flight.Contact Boeing for af- ter-repair inspection instructions and do the inspections at the compliance times specified by Boeing. Location(s) where repair #10 or #13 was done in accordance with Paragraph 3.B., PART 6 of this service bulletin. (a) -Before further flight.Contact Boeing for repair instructions, and do the repair. Any crack found in the repaired or modi- fied location(s). (a) Refer to Paragraph 3.B., Work Instructions, PART 6, Tables 1 and 2 for corresponding repair procedures. 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. This service bulletin has been approved by the FAA. In addition, the Manager of the FAA Seattle Aircraft Certification Office approves the inspection, modification and repair procedures with the corresponding compliance times specified in Tables 1 - 9 under Paragraph 1.E., Compliance, of Service Bulletin 747-53A2452, Revision 1, as an alternative method of compliance to the corresponding inspection and repair requirements of paragraph (i), (m), (n), (o), (p) and (q) of AD 2005-20-29. This AMOC is only for upper deck floor beam upper chords that have been inspected, modified or repaired in accordance with this service bulletin. When this service bulletin specifies contacting Boeing for repair instructions, the repair instructions must be approved by the FAA in accordance with paragraph (s) of the AD. All provisions of AD 2005-20-29 that are not specifically referenced in the above statement remain fully applicable and must be complied with accordingly. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 45 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 46 In addition, The Manager of the FAA Seattle ACO approves the inspection, repair, and modification procedures with the corresponding compliance times specified in Tables 1 - 9 under Paragraph 1.E., Compliance, of Service Bulletin 747-53A2452, Revision 1, as an alternative method of compliance (AMOC) to the corresponding inspection and repair requirements of paragraph (h), (i)(2), (i)(3), and (j) of FAA AD 2004-07-22 R1, for the inspection of Structural Significant Items (SSI) F-19B, F-19I, and F-20A of Supplemental Structural Inspection Document (SSID) D6-35022, Revision G, dated December 2000. This AMOC only applies to the areas inspected in accordance with this service bulletin. When this service bulletin 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, including the initial inspection threshold per paragraph (i) of AD 2004-07-22 R1, remain fully applicable and must be complied with accordingly. G. Manpower The table below shows an estimate of the man-hours necessary to do this inspection for each airplane. This estimate is for direct labor only, done by an experienced crew. Adjust the estimate with operator man-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 examine the work — Time to cure the materials — Time to make the parts — Time to find the tools. Group 1: TABLE 1 Elapsed Time (Hours)Man-HoursNumber of PersonsTask 29.50236.008Open Access 45.00180.004Inspect 31.75254.008Close Access 106.25670.00TOTAL FOR EACH GROUP 1 AIRPLANE Group 2: TABLE 2 Elapsed Time (Hours)Man-HoursNumber of PersonsTask 21.25170.008Open Access 45.00180.004Inspect 23.50188.008Close Access 89.75538.00TOTAL FOR EACH GROUP 2 AIRPLANE Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 46 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 47 Group 3: TABLE 3 Elapsed Time (Hours)Man-HoursNumber of PersonsTask 29.50236.008Open Access 57.50230.004Inspect 31.75254.008Close Access 118.75720.00TOTAL FOR EACH GROUP 3 AIRPLANE Group 4: TABLE 4 Elapsed Time (Hours)Man-HoursNumber of PersonsTask 21.25170.008Open Access 47.50190.004Inspect 23.50188.008Close Access 92.25548.00TOTAL FOR EACH GROUP 4 AIRPLANE Group 5: TABLE 5 Elapsed Time (Hours)Man-HoursNumber of PersonsTask 30.50244.008Open Access 95.00380.004Inspect 32.50260.008Close Access 158.00884.00TOTAL FOR EACH GROUP 5 AIRPLANE Group 6: TABLE 6 Elapsed Time (Hours)Man-HoursNumber of PersonsTask 21.25170.008Open Access 50.00200.004Inspect 23.50188.008Close Access 94.75558.00TOTAL FOR EACH GROUP 6 AIRPLANE NOTE: More time will be necessary for repairs if cracks are found. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 47 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 48 H. Weight and Balance Changes The repairs in this service bulletin will affect the weight and balance of the airplane. However, because of the variation in weight, location and quantity of repairs, it is not possible to specify weight and balance changes in this service bulletin. It will be necessary for operators to calculate the weight and balance changes for each airplane based on the repairs that are accomplished. I. Electrical Load Data Not applicable. J. References 1. Existing Data: a. Boeing Service Bulletin 747-53-2327, 747-53A2349, 747-53A2431 b. Boeing Service Related Problem (SRP) 747-SRP-53-0122 c. Federal Aviation Administration (FAA) Airworthiness Directive (AD) 2004-07-22 R1, 2005-20-29 d. 747 Non-Destructive Testing (NDT) Manual Part 6, 51-00-00, Part 6, 53-10-53 e. 747-100/200/300 Aircraft Maintenance Manual (AMM) 25-16-01, 25-21-04, 25-22-01, 25-23-01, 25-24-02, 25-24-16, 25-24-18, 25-24-25, 25-24-33, 25-24-47, 25-25-01, 25-27-05, 25-28-07, 25-28-10, 25-31-05, 25-31-06, 25-33-12, 25-40-03, 25-59-01, 25-59-05, 53-21-02 f. 747-100/200/300 Structural Repair Manual (SRM) 51-30-05 g. 747-SP Structural Repair Manual (SRM) 51-30-05 2. Data Supplied with this Service Bulletin: None. 3. Installation Drawings Used in the Preparation of this Service Bulletin: None. K. Publications Affected 1. Publications: Chapter-SectionPublication 53-10-07747-100, -200, -300 Structural Repair Manual 53-19-03747SP Structural Repair Manual 2. Damage Tolerance Based Structural Inspections: Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 48 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 49 Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the Maintenance Program. This service bulletin affects FCS. DTI requirements for the structure affected are contained in Paragraph 1.E., Compliance of this service bulletin. L. Interchangeability and Intermixability of Parts Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts. M. Software Accomplishment Summary Not affected. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 49 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 50 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 50 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT BLANK PAGE ### Page 51 2. MATERIAL INFORMATION A. Material - Price and Availability None B. Industry Support Information Boeing warranty remedies are not available for the inspection and repair procedures given in this service bulletin. C. Parts Necessary for Each Airplane 1. Kits/Parts: None. 2. Parts and Materials Supplied by the Operator: NOTE: The number in the QTY column in the tables that follow is the number of parts necessary to accomplish one repair. 1. 2. More than one repair may be necessary if cracks are found. 3. Refer to 747 Structural Repair Manual Chapter 51 for alternative fasteners. TABLE 1 - Figure 7 Repair NamePart NumberQTY Repair StrapA (a)1 BoltBACB30NW6K410 CollarBACC30M610 NutplateBACN10JR3F(b) RivetBACR15CE3AD4(b) Make in accordance with FIGURE 7.(a) Dependent upon the number of floor panel attachment fastener holes affected by the repair.(b) TABLE 2 - Figure 9 Repair NamePart NumberQTY Repair StrapA (a)1 FillerB (a)1 BoltBACB30NW6K410 CollarBACC30M610 NutplateBACN10JR3F(b) Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 51 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 52 TABLE 2 - Figure 9 Repair NamePart NumberQTY RivetBACR15CE3AD4(b) Make in accordance with FIGURE 9.(a) Dependent upon the number of floor panel attachment fastener holes affected by the repair.(b) TABLE 3 - Figure 10 Repair NamePart NumberQTY Repair StrapA (a)1 FillerB (a)1 Repair ClipC (a)1 BoltBACB30MY6K7X3 BoltBACB30NW6K410 CollarBACC30M613 NutplateBACN10JR3F(b) RivetBACR15CE3AD4(b) Make in accordance with FIGURE 10.(a) Dependent upon the number of floor panel attachment fastener holes affected by the repair.(b) TABLE 4 - Figure 11 Repair NamePart NumberQTY Repair StrapA (a)1 FillerB (a)1 Repair StrapC (a)1 BoltBACB30NW6K52 BoltBACB30NW6K712 CollarBACC30M614 NutplateBACN10JR3F(b) RivetBACR15CE3AD4(b) Make in accordance with FIGURE 11.(a) Dependent upon the number of floor panel attachment fastener holes affected by the repair.(b) TABLE 5 - Figure 12 Repair NamePart NumberQTY Repair AngleA (a)1 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 52 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 53 TABLE 5 - Figure 12 Repair NamePart NumberQTY FillerB (a)1 Repair StrapC (a)1 BoltBACB30MY6K7X14 BoltBACB30NW6K52 BoltBACB30NW6K712 CollarBACC30M628 NutplateBACN10JR3F(b) RivetBACR15CE3AD3(b) Make in accordance with FIGURE 12.(a) Dependent upon the number of floor panel attachment fastener holes affected by the repair.(b) TABLE 6 - Figure 13 Repair NamePart NumberQTY Repair StrapA (a)1 FillerB (a)1 BoltBACB30NW6K312 CollarBACC30M612 NutplateBACN10JR3F(b) RivetBACR15CE3AD3(b) Make in accordance with FIGURE 13.(a) Dependent upon the number of floor panel attachment fastener holes affected by the repair.(b) TABLE 7 - Figure 14 Repair NamePart NumberQTY Repair AngleA (a)1 FillerB (a)1 BoltBACB30MY6K512 BoltBACB30NW6K412 CollarBACC30M624 NutplateBACN10JR3F(b) RivetBACR15CE3AD3(b) Make in accordance with FIGURE 14.(a) Dependent upon the number of floor panel attachment fastener holes affected by the repair.(b) Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 53 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 54 3. Parts Modified and Reidentified: None. 4. Parts Removed and Not Replaced: None. D. Parts Necessary to Change Spares None. E. Special Tooling - Price and Availability None. F. Special Tooling Necessary to do this Service Bulletin No special tools or equipment are necessary to do the change in this service bulletin. But, maintenance and overhaul tools in the manuals given in Paragraph 1.J., References, can be necessary. Examine operator tool supply to make sure all necessary tools are available. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 54 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 55 3. ACCOMPLISHMENT INSTRUCTIONS A. GENERAL INFORMATION CAUTION: KEEP THE WORK AREA, WIRES AND ELECTRICAL BUNDLES CLEAN OF METAL PARTICLES OR CONTAMINATION WHEN YOU USE TOOLS. UNWANTED MATERIAL, METAL PARTICLES OR CONTAMINATION CAUGHT IN WIRE BUNDLES CAN CAUSE DAMAGE TO THE BUNDLES. DAMAGED WIRE BUNDLES CAN CAUSE SPARKS OR OTHER ELECTRICAL DAMAGE. NOTE: 1. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for definition of the acronyms. 2. Obey all of the warnings and cautions given in the specified manual sections. 3. Unless shown differently, these dimensions and tolerances are used: – Linear dimensions are in inches – Tolerance on linear dimensions, other than rivet and bolt edge margins, is plus or minus 0.03 inch – Tolerance on rivet and bolt edge margin is plus or minus 0.05 inch – Angular tolerance is plus or minus 2 degrees – Hole dimensions for standard solid rivets and fasteners are in Structural Repair Manual (SRM) Chapter 51 – Torque limits to tighten nuts and bolts are in SRM Chapter 51 4. Use the approved fastener and process material substitutions in accordance with SRM Chapter 51. 5. If the length of any fastener specified in this service bulletin does not meet installation standards given in SRM Chapter 51, then a fastener of the same specification, or an approved substitute, with a length which meets the installation standards given in SRM Chapter 51 may be used. In addition, washers may be installed for fastener grip length in accordance with SRM Chapter 51. 6. A Detailed Inspection is defined as: An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirrors, magnifying lenses, etc. may be necessary. Surface cleaning and elaborate procedures may be required. 7. These work instructions refer to procedures included in other Boeing documents. When the words "refer to" are used and the operator has an accepted alternative procedure, the accepted alternative procedure can be used. When the words "in accordance with" are included in the instruction, the procedure in the Boeing document must be used. 8. Boeing Service Letter, 747-SL-51-048 Damage Reporting and Repair Plan/Design Guidelines, is an acceptable procedure to request information from Boeing for additional structural repair instructions. The Service Letter describes what information must be provided to Boeing before a structural repair can be provided. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 55 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 56 9. If it is necessary to remove more parts for access, you can remove those parts. If you can get access without removing identified parts, it is not necessary to remove all of the identified parts. Jacking and shoring limitations must be observed. 10. Where the work instructions include installation of a kept part, a new or serviceable part with the same part number can be installed as an alternative to the kept part. 11. For the purposes of this service bulletin, flight-cycles during which cabin differential pressure is at 2.0 psi or less do not need to be counted when determining the number of flight cycles that have occurred on the airplane. However, any flight cycle with momentary spikes in cabin differential pressure above 2.0 psi must be counted as a full pressure flight cycle. For this provision to apply, cabin pressure records must be maintained for each airplane. Fleet averaging of cabin pressure is not allowed. 12. For initial and repeat inspections of unrepaired and unmodified floor panel attachment holes, either the open hole HFEC inspection method or the surface HFEC inspection method can be used. At hole locations where a repair or modification procedure has been done, do the type of inspection specified in paragraph 1.E., Compliance, depending on which repair was done. 13. The area of the STA 380 floor beam outboard of left and right BL 40 is inspected in accordance with Boeing Service Bulletin 747-53A2431, "Fuselage - Floors - Upper Deck Floor Beam Inspection at STA 340, 360, and 380." 14. Areas 1 and 2 are also visually inspected in accordance with Boeing Service Bulletin 747-53A2349, "Fuselage - Inspections Based on Fatigue Test Results". 15. FIGURE 2 shows the inspection areas for the affected airplane groups. 16. If affected floor beams or floor beam upper chords have been previously replaced with new parts, the inspection threshold for the replaced part should be counted from the time of the replacement. 17. For purposes of the inspections in this service bulletin, "permanent" fastener locations are defined as all fastener locations, except floor panel attachment fastener locations. 18. Figures 9 and 10 are for upper chords that have forward and aft flanges of the same thickness. Figures 11, 12, 13 and 14 are for upper chords with forward and aft flanges with different thickness. All other figures are applicable to either configuration. 19. In Figures 11, 12, 13 and 14 the typical illustrations show the thick flange on the forward side of the floor beam. However, at STA 1000, the thick flange is on the aft side of the floor beam. 20. On Group 1 - 4 airplanes, the floor beams at STA 760, 780, and 800 are not installed on all airplanes. 21. On Group 1 - 4 airplanes, it is not necessary to inspect the life raft support structure installed aft of the upper deck floor beams from STA 820 - 860. 22. On all affected airplanes, the STA 380 floor beam is only affected between LBL and RBL 40. The parts of the STA 380 floor beam outboard of BL 40 are inspected in accordance with Service Bulletin 747-53A2431. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 56 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 57 B. WORK INSTRUCTIONS PART 1 - UPPER DECK ACCESS 1. Group 1, 3, 5: Remove the equipment that follows from the upper deck for access to the upper chords of the upper deck floor beams from above: Refer to AMM Subject as an accepted procedureEquipment 747-100/200/300 AMM 25-16-01Flight Compartment Floor Covering 747-100/200/300 AMM 25-24-16Upper Deck Closets 747-100/200/300 AMM 25-24-18 747-100/200/300 AMM 25-24-25 747-100/200/300 AMM 25-24-47 747-100/200/300 AMM 25-25-01Upper Deck Passenger Seat 747-100/200/300 AMM 25-27-05Upper Deck Floor Covering 747-100/200/300 AMM 25-31-05Upper Deck Galleys 747-100/200/300 AMM 25-31-06 747-100/200/300 AMM 25-40-03Upper Deck Lavatories 747-100/200/300 AMM 53-21-02Upper Deck Floor Panels -Crew Rest Area NOTE: All of the equipment listed above may not be installed on all affected airplanes. This list is only intended to show equipment typically installed in the upper deck cabin on a typical 747 Passenger airplane. 2. Group 2, 4, 6: Remove the equipment that follows from the upper deck for access to the upper chords of the upper deck floor beams from above: Refer to AMM Subject as an accepted procedureEquipment 747-100/200/300 AMM 25-16-01Flight Compartment Floor Covering 747-100/200/300 AMM 25-25-01Upper Deck Passenger Seat 747-100/200/300 AMM 25-27-05Upper Deck Floor Covering 747-100/200/300 AMM 25-24-02Closets 747-100/200/300 AMM 25-24-16 747-100/200/300 AMM 25-24-18 747-100/200/300 AMM 25-24-25 747-100/200/300 AMM 25-24-33 747-100/200/300 AMM 25-24-47 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 57 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 58 Refer to AMM Subject as an accepted procedureEquipment 747-100/200/300 AMM 25-33-12Crew Galley - Upper Deck 747-100/200/300 AMM 25-40-03Lavatory 747-100/200/300 AMM 53-21-02Upper Deck Floor Panels -Crew Rest Area NOTE: All of the equipment listed above may not be installed on all affected airplanes. This list is only intended to show equipment typically installed in the upper deck cabin on a typical 747 Special Freighter airplane. PART 2 - MAIN DECK ACCESS 1. Group 1, 3, 5: Remove the equipment that follows from the main deck as necessary for access to the inspection area from below. Refer to AMM Subject as an accepted procedureEquipment 747-100/200/300 AMM 25-21-04Ceiling Insulation 747-100/200/300 AMM 25-22-01Ceiling Access Panels 747-100/200/300 AMM 25-23-01Passenger Service Units 747-100/200/300 AMM 25-25-01Passenger Seats 747-100/200/300 AMM 25-28-07Center Overhead Stowage Compartments 747-100/200/300 AMM 25-28-10Side Overhead Stowage Compartments NOTE: All of the equipment listed above may not be installed on all affected airplanes. This list is only intended to show equipment typically installed in the ceiling of the main deck cabin on a typical 747 Passenger airplane. 2. Group 2, 4, 6: Remove the equipment that follows from the main deck as necessary for access to the applicable inspection area from below. Refer to AMM Subject as an accepted procedureEquipment 747-100/200/300 AMM 25-59-01Main Deck Cargo Compartment Ceiling Lining 747-100/200/300 AMM 25-59-05Main Deck Ceiling Insulation NOTE: All of the equipment listed above may not be installed on all affected airplanes. This list is only intended to show equipment typically installed in the ceiling of the main deck cabin on a typical 747 Special Freighter airplane. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 58 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 59 PART 3 - OPEN-HOLE HFEC INSPECTION METHOD (AREA 1 AND AREA 2 FLOOR PANEL ATTACHMENT FASTENER LOCATIONS ONLY) 1. Remove equipment from the upper deck for access to the upper chords of the upper deck floor beams from above. Refer to Part 1 as an accepted procedure. 2. Do open hole High Frequency Eddy Current (HFEC) inspection of the upper chord of the upper deck floor beams for cracks at the floor panel attachment fastener locations in accordance with FIGURE 3. a. If no crack indications are found, install the floor panels and equipment that were removed for access to the area. Do repeat inspections in accordance with Paragraph 1.E., Compliance. NOTE: As an alternative if no cracks are found, a new inspection threshold can be obtained by doing one of the options that follow: 1. Do the fastener hole modification in accordance with FIGURE 4. After the modification is accomplished, do repeat inspections in accordance Paragraph 1.E., Compliance. 2. Do one of the repair procedures in accordance with PART 6. After repair, do repeat inspections in accordance Paragraph 1.E., Compliance. b. If crack indications are found, do the repair in accordance with PART 6. 3. Put the airplane back to a serviceable condition. Do repeat inspections at repaired and unrepaired locations in accordance with Paragraph 1.E., Compliance. NOTE: Any floor panel attachment fastener hole under a repair strap that is not repaired or modified (in accordance with FIGURE 4 or in accordance with Paragraph 3.B., PART 6) and is not at least five fasteners away from the end of the repair strap is not considered a repaired hole. PART 4 - SURFACE HFEC INSPECTION METHOD (AREA 1 AND AREA 2 FLOOR PANEL ATTACHMENT FASTENER LOCATIONS ONLY) 1. Remove equipment from the main deck as necessary for access to the inspection area from below. Refer to Part 2 as an accepted procedure. 2. Modify the floor panel attachment clipnuts and do surface High Frequency Eddy Current (HFEC) inspections in Area 1 and Area 2 for cracks in the upper deck floor beams at floor panel attachment fastener locations in accordance with FIGURE 5. a. If no crack indications are found, install the equipment that was removed for access to the area. Do repeat inspections in accordance with Paragraph 1.E., Compliance. b. If crack indications are found, do the repair in accordance with PART 6. 3. Put the airplane back to a serviceable condition. Do repeat inspections at repaired and unrepaired locations in accordance with Paragraph 1.E., Compliance. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 59 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT ### Page 60 NOTE: Any floor panel attachment fastener hole under a repair strap that is not repaired or modified (in accordance with FIGURE 4 or in accordance with Paragraph 3.B., PART 6) and is not at least five fasteners away from the end of the repair strap is not considered a repaired hole. PART 5 - SURFACE HFEC INSPECTION METHOD (AREA 1 AND AREA 2 PERMANENT FASTENER LOCATIONS ONLY) 1. If not already done, remove equipment from the main deck as necessary to get access to the area from below. Refer to Part 2 as an accepted procedure. 2. Do surface HFEC inspections for cracks in the upper chords of the upper deck floor beams in Area 1 and Area 2 at permanent fastener locations in accordance with FIGURE 18. 3. Do surface HFEC inspections for cracks in the lower chords of the upper deck floor beams in Area 1 at permanent fastener locations in accordance with FIGURE 18. 4. If no crack indications are found, install the equipment that was removed for access to the area. Do repeat inspections in accordance with Paragraph 1.E., Compliance. 5. If crack indications are found, contact Boeing for repair instructions, and do the repair. 6. Put the airplane back to a serviceable condition. Do repeat inspections at permanent fastener locations in accordance with Paragraph 1.E., Compliance. PART 6 - AREA 1 and AREA 2 FLOOR PANEL FASTENER HOLE REPAIR (Can also be done as a modification) 1. If not already done, remove equipment and floor panels as necessary for access to the affected fastener hole from above. Refer to Part 1 as an accepted procedure. 2. If not already done, remove equipment from the main deck as necessary for access to the affected fastener location from below. Refer to Part 2 as an accepted procedure. 3. For hole locations where this repair procedure is being accomplished as a modification (no crack has been found), make the hole diameter 1/64 oversize, then go to step 5. 4. For hole locations where a crack indication was found during an inspection, do the following: NOTE: It is acceptable to skip this step at any fastener where the chord will be trimmed in accordance with FIGURE 8. For example, if the crack extends to the edge of the upper chord, or if you think that oversizing the crack will result in edge margin less than 1.3D, then you can do a trim out in accordance with FIGURE 8 instead of doing this step. a. Make the affected fastener hole diameter 1/64 inch oversize. b. Do an open-hole HFEC inspection of the fastener hole for cracks in accordance with 747 NDT Part 6, 51-00-00, Figure 1, 11, or 16. c. If crack indications are found, repeat the hole oversize and open-hole HFEC inspection until no crack indication is found. d. If no crack indication is found, continue to the next step. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 03, 2003 747-53A2452Revision 1: July 16, 2012 60 of 142 BOEING SERVICE BULLETIN 747-53A2452 ALERTALERT The text continues at https://openairdocs.org/service-documents/boeing/747-53a2452/file/8af7982f91b0.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.