# Boeing Alert Service Bulletin 737-53A1240: Revision 1 - Rights: © The Boeing Company. Filed by the FAA in regulations.gov docket FAA-2011-1255; AD 2012-12-05 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. - Document: [Boeing Alert Service Bulletin 737-53A1240](https://openairdocs.org/service-documents/boeing/737-53a1240.md) - Title as filed: Boeing - Service Bulletin - SB 737-53 A1240-01 - Pages: 155 - PDF: https://openairdocs.org/files/sha256/d2/7d/d27d40919a7808a32a041088c6736699a28ac9d1c44f10845b155d7195a8f755 - Page: https://openairdocs.org/service-documents/boeing/737-53a1240/file/d27d40919a78 ## 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 737 Service Bulletin ALERT Number: 737-53A1240 Original Issue: April 10, 2003 Revision 1: June 29, 2010 ATA System: 5311 SUBJECT: FUSELAGE - Frames and Bulkheads - Forward Door, Inspection and Repair of Inner Frame Chord, Stringers and Intercostals. Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15 CFR 730-774). An export license may be required before it is used for development, production or use by foreign persons from specific countries. The controller of this data has the individual responsibility to abide by all export laws. 9E991ECCN: BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET Copyright © 2003 The Boeing Company Unpublished Work - All Rights Reserved Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable subject matter. Boeing also claims copyright in this document as a compilation and/or collective work. This document includes proprietary information owned by The Boeing Company and/or one or more third parties. Treatment of the document and the information it contains is governed by contract with Boeing. For more information, contact The Boeing Company, P.O. Box 3707, Seattle, Washington 98124. Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, Dreamliner, BBJ, DC-8, DC-9, DC-10, KC-10, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8A, Poseidon and the Boeing livery are all trademarks owned by The Boeing Company; and no trademark license is granted in connection with this document unless provided in writing by Boeing. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 1 of 155 4.0 ### Page 2 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 2 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT BLANK PAGE ### Page 3 Table of Contents Revision Transmittal Sheet ............................................ 5 Summary ...................................................... 7 1. PLANNING INFORMATION ........................................ 1 1 A. Effectivity ............................................... 1 1 1. Airplanes ............................................ 1 1 2. Spares Affected ........................................ 2 3 B. Concurrent Requirements ...................................... 2 3 C. Reason ................................................ 2 3 D. Description .............................................. 2 4 E. Compliance .............................................. 2 5 F. Approval ............................................... 2 8 G. Manpower .............................................. 2 8 H. Weight and Balance Changes .................................... 3 0 I. Electrical Load Data ......................................... 3 0 J. References .............................................. 3 1 1. Existing Data: ......................................... 3 1 2. Data supplied with this Service Bulletin: ........................... 3 1 3. Installation Drawings Used in the Preparation of this Service Bulletin: ........... 3 1 K. Publications Affected ........................................ 3 2 L. Interchangeability and Intermixability of Parts ........................... 3 2 2. MATERIAL INFORMATION ........................................ 3 3 A. Material - Price and Availability ................................... 3 3 B. Industry Support Information .................................... 3 4 C. Parts Necessary For Each Airplane ................................. 3 4 1. Kits/Parts: ........................................... 3 4 2. Parts and Materials Supplied by the Operator: ........................ 4 0 3. Parts Modified and Reidentified: ............................... 4 1 4. Parts Removed and Not Replaced: .............................. 4 1 D. Parts Necessary to Change Spares ................................. 4 1 E. Special Tooling - Price and Availability ............................... 4 1 F. Special Tooling Necessary to do this Service Bulletin ....................... 4 1 3. ACCOMPLISHMENT INSTRUCTIONS .................................. 4 3 A. GENERAL INFORMATION ..................................... 4 3 B. WORK INSTRUCTIONS ....................................... 4 4 FIGURE 1: STA 348.2 DOOR FRAME - OPEN ACCESS [Group 1] ................... 5 0 FIGURE 2: STOP FITTING AND INNER SKIN - REMOVAL [Group 1] .................. 5 2 FIGURE 3: FRAME INSPECTION [Group 1] ............................... 5 4 FIGURE 4: STOP FITTING AND INNER SKIN - INSTALLATION [Group 1] ............... 5 6 FIGURE 5: STA 348.2 DOOR FRAME - CLOSE ACCESS [Group 1] .................. 6 3 FIGURE 6: STA 348.2 DOOR FRAME ACCESS AND STOP FITTING REMOVAL [Group 2-3] .... 6 5 FIGURE 7: STA 348.2 DOOR FRAME INSPECTION [Group 2-3] .................... 7 3 FIGURE 8: STA 348.2 FRAME DOOR STOPS AT STRINGER S-7L TO S-15L - MISSING FASTENER INSPECTION [Group 2-3] ................................... 7 9 FIGURE 9: STA 348.2 DOOR FRAME, LEFT SIDE, INBOARD CHORD AND REINFORCEMENT ANGLE - REMOVAL [Group 3] ..................................... 8 2 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 3 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 4 FIGURE 10: STA 348.2 DOOR FRAME, LEFT SIDE, INBOARD CHORD AND REINFORCEMENT ANGLE - ASSEMBLY [Group 3] .................................... 8 5 FIGURE 11: STA 348.2 TO STA 360, LEFT SIDE, S-14L INTERCOSTAL - REMOVAL [Group 3] . . . 89 FIGURE 12: STA 348.2 TO STA 360, LEFT SIDE, S-14L INTERCOSTAL - INSTALLATION [Group 3] . 94 FIGURE 13: STA 348.2 TO STA 360, LEFT SIDE, S-15L INTERCOSTAL - REMOVAL [Group 3] . . . 100 FIGURE 14: STA 348.2 TO STA 360, LEFT SIDE, S-15L INTERCOSTAL - INSTALLATION [Group 3] . 106 FIGURE 15: STA 348.2 TO STA 351.2, LEFT SIDE, S-16L INTERCOSTAL - REMOVAL [Group 3] . . 113 FIGURE 16: STA 351.2 TO STA 360, LEFT SIDE, S-16L INTERCOSTAL - REMOVAL [Group 3] . . . 117 FIGURE 17: STA 351.2 TO STA 360, LEFT SIDE, S-16L INTERCOSTAL - INSTALLATION [Group 3] . 122 FIGURE 18: STA 348.2 TO STA 351.2, LEFT SIDE, S-16L INTERCOSTAL - INSTALLATION [Group 3] . 131 FIGURE 19: STA 348.2 DOOR FRAME, LEFT SIDE, CHORD AND REINFORCEMENT ANGLE - INSTALLATION [Group 3] .................................. 1 3 6 FIGURE 20: STA 348.2 TO STA 351.2, LEFT SIDE, SHEAR WEB - INSTALLATION [Group 3] .... 1 4 0 FIGURE 21: STA 348.2 DOOR FRAME CLOSE ACCESS AND STOP FITTING AND SHEAR WEB INSTALLATION [Group 2-3] ................................. 1 4 5 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 4 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 5 Commercial Airplanes 737 Service Bulletin ALERT Revision Transmittal SheetNumber: 737-53A1240Original Issue: April 10, 2003 Revision 1: June 29, 2010 ATA System: 5311 SUBJECT: FUSELAGE - Frames and Bulkheads - Forward Door, Inspection and Repair of Inner Frame Chord, Stringers and Intercostals. This Revision includes all pages of the service bulletin. COMPLIANCE INFORMATION RELATED TO THIS REVISION No more work is necessary on airplanes changed in accordance with the original issue of this service bulletin. All 737-100/200/300/400/500 Series Airplanes are added to new Groups 2 and 3 of this service bulletin effectivity. Federal Aviation Administration (FAA) Airworthiness Directives 98-11-04 R1, 2004-09-09, 2008-08-23 and 2008-09-13 are related to this service bulletin. REASON FOR REVISION This revision is sent to add all 737-100/200/300/400/500 series airplanes to the service bulletin effectivity and to remove intercostal inspections from the Service Bulletin. Intercostal Inspections between STA 348.2 and STA 360 are now covered in Service Bulletin 737-53A1204, Revision 2. These sections are changed: 1. Added 737-100/200 airplanes, line numbers 1-32 to new Group 2 in Paragraph 1.A., Effectivity. 2. Added 737-200/300/400/500 airplanes, line numbers 33-3132 to new Group 3 in Paragraph 1.A., Effectivity. 3. Added Service Bulletin 737-53A1204, Revision 2 intercostal inspections to Paragraph 1.B., Concurrent Requirements. 4. Added new service history information to Paragraph 1.C., Reason. 5. Removed the intercostal inspection from Paragraph 3.B., Work Instructions and FIGURE 3 for Group 1 airplanes. 6. Added instructions for new Group 2 and 3 airplanes and added Maintenance Zone Tables to Paragraph 1.D., Description. 7. Added Compliance Table 2 and 3 for new Group 2 and 3 airplanes to Paragraph 1.E., Compliance. 8. Added Damage Tolerance Based Structural Inspections statement to Paragraph 1.K., Publications Affected. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 5 of 155 ### Page 6 9. Added kit pricing and availability for new Kits 65C38828-1, 65C38828-2 and 65C39000-1 to Paragraph 2.A., Material - Price and Availability. 10. Added new Fastener Kit 65C38828-1 for new Group 2 and 3 airplanes and added new Replacement Parts Kits 65C38828-2 and 65C39000-1 for new Group 3 airplanes to Paragraph 2.C., Parts Necessary for Each Airplane. 11. Added Part 2 - Access, Part 3 - Inspection and Part 5 - Close Access for new Group 2 and 3 airplanes to Paragraph 3.B., Work Instructions. 12. Added Part 4 - Repair for new Group 3 airplanes to Paragraph 3.B., Work Instructions. 13. Added optional NDT inspection reference to FIGURE 3. 14. Added FIGURE 6, FIGURE 7 and FIGURE 21 for access, inspection and close access for the new Group 2 and 3 airplanes. 15. Added FIGURE 9 through FIGURE 20 for the repair of the frame inner chord, reinforcement angle, stringer S-14L, S-15L and S-16L intercostals in Part 4 - Repair, for the new Group 3 airplanes. 16. Added FIGURE 8 for inspections for missing fasteners in the STA 348.2 frame inner chord adjacent to the door stop at stringer S-7L through S-15L for the new Group 2 and 3 airplanes. Paragraph 1.A., Effectivity, shows changes of airplane operators. Each operator should examine the Paragraph 1.A., Effectivity for changes. Vertical lines are put on the left edge of each page, except in Paragraph 1.A., Effectivity, to show the location of important changes. Pages with no vertical lines have no important changes. REVISION HISTORY April 10, 2003Original Issue: June 29, 2010Revision 1: BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 6 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 7 Commercial Airplanes 737 Service Bulletin ALERT SummaryNumber: 737-53A1240Original Issue: April 10, 2003 Revision 1: June 29, 2010 ATA System: 5311 SUBJECT: FUSELAGE - Frames and Bulkheads - Forward Door, Inspection and Repair of Inner Frame Chord, Stringers and Intercostals. 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 Refer to Paragraph 1.B., Concurrent Requirements. BACKGROUND This service bulletin gives instructions to inspect the Station (STA) 348.2 frame for cracks under the stop fittings. This service bulletin also gives instructions to inspect for missing fasteners common to the STA 348.2 frame at S-7L through S-15L. Undetected or remaining cracks in the frame will propagate by normal fatigue due to cyclic cabin pressure loading. If cracks continue to propagate, the stop fittings will become ineffective. This can result in a possible rapid decompression and a potential separation of the forward entry door from the aircraft. Boeing has received reports of cracks in the STA 348.2 frame on six 737-200 cargo airplanes. The STA 348.2 frame is a body frame aft of the forward entry door cutout. The cracks were located under the stop fittings at Stringer 15L and 16L. Since the release of the original issue of this service bulletin, Boeing has received reports of STA 348.2 frame cracking at S-15L above the two outboard fasteners attaching the frame inner chord and door stop fitting. The cracking was reported on seven passenger airplanes that had accumulated between 19,185 and 64,800 flight cycles. Spares history also shows that seventeen frame chords have been ordered in the last ten years. Cracks have also been found in the outboard chord at S-16L. Boeing has received reports of ten passenger airplanes with missing fasteners in the STA 348.2 frame inner chord at stringer S-7L through S-15L. Boeing Service Related Problem (SRP) 737-SRP-53-0149 and 737-SRP-53-0306 are related to this service bulletin. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 7 of 155 ### Page 8 ACTION (PRR 35005-287RS, PRR 35005-246RS) Group 1: Accomplish the inspection by removal of the stop fittings at stringers S-14L, S-15L, and S-16L. Eddy current inspect the STA 348.2 frame inner chord and the stop fitting holes. If any crack is found, contact Boeing for repair instruction and do the repair. Group 2-3: Remove the forward entry door reveal, scuff plate, cover plate, and lining support. Remove the stop fittings at stringers S-14L, S-15L and S-16L. Do a detailed inspection and an eddy current inspection of the STA 348.2 frame inner chord over a 4.00 inch length centered on the removed stop fittings at S-15L and S-16L. Do an open hole eddy current inspection of the frame common to the stop fitting holes. Remove the shear web between STA 351.2 to STA 348.2 to get access to the aft side of the STA 348.2 frame. Do an open hole eddy current inspection of the fastener holes in the shear web. Do a detailed inspection of the frame outer chord, frame inner chord and reinforcement angle. Group 2: If any crack is found, contact Boeing for repair instruction and do the repair. Group 3: If any crack is found in the STA 348.2 frame outer chord, contact Boeing for repair instruction and do the repair. If any crack is found in the STA 348.2 frame inner chord, reinforcement angle, or the shear web, do the repair in accordance with Paragraph 3.B., Work Instructions of this service bulletin. If cracks are found in the S-14L, S-15L, and S-16L doorstop intercostals as a result of SB 737-53A1204R2 inspection, repair in accordance with Accomplishment Instructions Paragraph 3.B.4. Part 4 - Repair. Group 2-3: Do a detailed inspection of the STA 348.2 frame inner chord for missing fasteners at stringers S-7L through S-15L. If any fastener is missing, contact Boeing and do the work instructed by Boeing. EFFECTIVITY All 737-100/200/200C/300/400/500 Airplanes. Refer to Paragraph 1.A., Effectivity for the list of affected airplanes. COMPLIANCE Federal Aviation Administration (FAA) Airworthiness Directives 98-11-04 R1, 2008-08-23 and 2008-09-13 are related to this service bulletin. FAA Airworthiness Directive 2004-09-09 mandates the original issue of this service bulletin. The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to Revision 1 of this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in Revision 1 of this service bulletin mandatory. Refer to Paragraph 1.E., Compliance. INDUSTRY SUPPORT INFORMATION Boeing warranty remedies are not available for the inspection and/or repair procedures given in this service bulletin. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 8 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 9 (OCR) BOEING SERVICE BULLETIN 737-53A1240 ALERT ALERT MANPOWER Refer to Paragraph 1.G., Manpower. MATERIAL INFORMATION Boeing Supplied Kits/Parts. Refer to Paragraph 2.A., Material - Price and Availability. 7000000000000 MAIN CARGO DOOR APPLICABLE TO 737-200C DO A HFEC INSPECTION OF THE STA 348.2 FRAME AT STRINGER S-14L, S-15L AND S-16L STOP FITTINGS AND SHEAR WEB FOR CRACKS. IF ANY CRACK IS FOUND IN THE FRAME OR SHEAR WEB, DO THE REPAIR GIVEN IN THIS SERVICE BULLETIN OR CONTACT BOEING. DO A DETAILED INSPECTION OF THE STA 348.2 FRAME INNER CHORD FOR MISSING FASTENERS AT STRINGERS S-7L THROUGH S-15L. IF ANY FASTENERS ARE MISSING CONTACT BOEING AND DO THE WORK INSTRUCTED BY BOEING. V73727 Original Issue: April 10, 2003 Revision 1: June 29, 2010 BOEING PROPRIETARY - 737-53A1240 Copyright © Unpublished Work - See page 1 for details. 9 of 155 ### Page 10 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 10 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT BLANK PAGE ### Page 11 Commercial Airplanes 737 Service Bulletin ALERT Number: 737-53A1240 Original Issue: April 10, 2003 Revision 1: June 29, 2010 ATA System: 5311 SUBJECT: FUSELAGE - Frames and Bulkheads - Forward Door, Inspection and Repair of Inner Frame Chord, Stringers and Intercostals. 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 This service bulletin is for the airplanes shown below. Refer to PRR 35436-RS for data about this change. DESCRIPTIONCONFIGURATIONGROUP All 737-200C Cargo Airplanes.-1 737-100/200 Passenger Airplanes, Line Number 1 through 32.-2 737-100/200/300/400/500 Passenger Airplanes, Line Number 33 through 3132. -3 Airplane Models: 737-100, 737-200, 737-200C, 737-300, 737-400, 737-500 GroupVariable Number 2PA001 - PA013 3PA014 - PA022 2PA099 3PA231 - PA232 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 11 of 155 ### Page 12 GroupVariable Number 3PC001 - PC005 2PG001 - PG014 3PG015 - PG075 2PG199 3PG201 - PG230 3PG251 - PG255 2PG271 - PG272 3PG273 - PG279 2PG301 3PG302 - PG314 3PG331 - PG332 3PG351 - PG356 3PG375 3PG401 - PG403 3PG431 - PG442 3PG471 - PG475 3PG501 - PG505 3PG571 - PG586 3PG621 - PG630 3PG651 - PG652 3PG701 - PG705 3PH001 3PH011 - PH013 3PH021 - PH024 3PH701 - PH715 3PH731 - PH732 3PH741 - PH743 3PJ001 - PJ009 3PJ031 - PJ032 3PJ071 - PJ072 3PJ101 - PJ119 3PJ201 - PJ219 3PJ301 - PJ302 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 12 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 13 GroupVariable Number 3PJ551 - PJ561 3PJ601 - PJ615 3PJ811 3PJ816 - PJ817 3PK026 - PK029 3PK041 - PK053 3PK061 - PK070 3PK081 - PK082 3PK091 - PK099 3PK101 - PK103 3PK111 - PK120 3PK141 - PK146 3PK201 - PK204 3PK211 - PK223 3PK231 - PK241 3PK251 - PK258 3PK271 - PK274 3PK281 - PK289 3PK291 3PK301 - PK318 3PK341 3PK351 - PK361 3PK391 3PK431 - PK433 3PK451 - PK452 3PK461 - PK469 3PK495 3PK501 - PK504 3PK511 - PK515 3PK519 3PK521 - PK528 3PK541 - PK565 3PK581 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 13 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 14 GroupVariable Number 3PK591 - PK599 3PK601 - PK617 3PK621 - PK637 3PK641 - PK642 3PK661 - PK666 3PK671 - PK681 3PK691 - PK697 3PK711 - PK716 3PK731 - PK765 3PK771 - PK779 3PK801 - PK804 3PK819 - PK827 3PK830 3PK861 - PK863 3PK871 - PK874 3PK881 - PK884 3PK901 - PK938 3PK971 - PK974 3PL001 - PL028 3PL061 3PL081 3PL101 - PL113 3PL151 3PL171 - PL172 3PL201 - PL203 3PL221 3PL401 - PL417 3PL421 3PL441 3PL451 - PL456 3PL471 3PL491 3PL501 - PL506 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 14 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 15 GroupVariable Number 3PL551 - PL562 3PL581 3PL601 - PL603 3PL611 3PL621 - PL626 3PL631 - PL632 3PL711 - PL712 3PL716 - PL747 3PL756 3PL758 3PL761 - PL770 3PL781 - PL788 3PL793 3PL801 - PL803 3PM001 - PM006 3PM016 - PM017 3PM021 - PM023 3PM051 - PM066 3PM101 - PM119 3PM141 - PM142 3PM171 3PM181 3PM251 - PM255 3PM281 - PM283 3PM381 - PM399 3PM401 - PM417 3PM541 - PM564 3PN001 - PN002 3PN021 - PN043 3PN081 - PN086 3PN101 - PN117 3PN131 - PN163 3PN401 - PN420 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 15 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 16 GroupVariable Number 3PN431 - PN433 3PN451 - PN456 3PN471 - PN474 3PN481 3PN491 - PN493 3PN501 - PN502 3PN511 - PN512 3PN521 3PP001 - PP054 3PP101 - PP169 3PP181 - PP199 3PP201 - PP205 3PP221 3PP231 - PP243 3PP281 - PP286 3PP301 - PP305 3PP351 - PP353 3PP376 - PP384 3PP391 - PP393 3PP401 - PP440 3PP471 - PP475 3PP501 - PP522 3PP631 - PP634 3PP651 - PP652 3PP671 - PP699 3PP701 - PP733 3PP771 - PP779 3PP801 - PP808 3PP821 - PP827 3PP831 - PP848 3PP851 - PP852 3PP861 - PP877 3PP891 - PP899 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 16 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 17 GroupVariable Number 3PP901 - PP936 3PP946 - PP948 3PP951 - PP952 3PP961 - PP967 3PP981 - PP991 3PP993 3PQ001 - PQ016 3PQ026 - PQ041 3PQ051 - PQ092 3PQ101 - PQ199 3PQ201 - PQ202 3PQ221 - PQ237 3PQ241 - PQ243 3PQ251 - PQ267 3PQ281 - PQ299 3PQ301 - PQ307 3PQ331 - PQ332 3PQ341 - PQ348 3PQ361 - PQ373 3PQ391 - PQ395 3PQ401 - PQ418 3PQ421 3PQ431 - PQ438 3PQ447 - PQ448 3PQ451 3PQ454 3PQ471 - PQ475 3PQ479 - PQ481 3PQ486 - PQ487 3PQ491 - PQ493 3PQ771 - PQ772 3PQ791 - PQ793 3PQ801 - PQ805 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 17 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 18 GroupVariable Number 3PQ931 - PQ935 3PQ951 3PQ971 - PQ997 3PR001 - PR017 3PR021 - PR034 3PR041 - PR045 3PR061 - PR072 3PR077 - PR082 3PR091 - PR092 3PR096 3PR101 3PR121 - PR122 3PR131 - PR132 3PR141 - PR143 3PR161 - PR172 3PR181 3PS601 - PS631 3PS636 - PS638 3PS641 - PS644 3PS651 - PS657 3PS666 - PS669 3PS691 - PS692 3PS701 - PS706 3PS751 - PS799 3PS811 3PS836 - PS837 3PS841 - PS846 3PS851 - PS852 3PS856 3PS861 - PS863 3PS866 - PS868 3PS871 - PS874 3PS896 - PS897 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 18 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 19 GroupVariable Number 3PS901 - PS941 3PS956 - PS957 3PS961 - PS963 3PS971 - PS978 3PT001 - PT015 3PT021 - PT031 3PT041 - PT064 3PT101 - PT105 3PT121 - PT138 3PT146 - PT148 3PT161 - PT170 3PT181 - PT188 3PT211 - PT220 3PT295 3PT301 - PT309 3PT331 - PT360 3PT381 - PT399 3PT401 - PT438 3PT501 - PT517 3PT561 - PT565 3PT581 - PT586 3PT611 - PT621 3PT641 - PT644 3PT651 - PT656 3PT671 - PT672 3PT681 - PT685 3PT701 - PT703 3PT716 - PT717 3PT721 - PT725 3PT801 - PT834 3PT851 - PT854 3PT871 - PT886 3PT901 - PT930 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 19 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 20 GroupVariable Number 3PT971 - PT973 3PT981 - PT985 3PT996 3PU001 - PU025 3PU301 3PU311 - PU313 3PV001 - PV055 3PV201 - PV209 3PV226 - PV229 3PV231 - PV237 3PV271 - PV272 3PV281 - PV287 3PV296 3PV301 - PV302 3PV351 3PV356 - PV357 3PW001 - PW054 3PW061 - PW068 3PW072 3PW086 - PW088 3PW091 - PW094 3PW101 - PW102 3PW106 3PW111 - PW120 3PW156 - PW157 3PW161 - PW171 3PW201 - PW252 3PW261 - PW268 3PW271 - PW276 3PW278 3PW281 - PW293 3PW296 3PW301 - PW327 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 20 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 21 GroupVariable Number 3PW401 - PW408 3PW411 - PW418 3PW421 - PW424 3PW431 - PW435 3PW441 - PW450 3PW461 - PW467 3PW501 - PW504 3PW511 - PW522 3PW524 - PW550 3PW556 - PW557 3PW561 - PW564 3PW571 - PW576 3PW591 - PW596 3PW611 - PW622 3PW631 - PW637 3PW661 - PW662 3PW681 - PW683 3PW701 - PW702 3PW711 - PW717 3PW741 - PW742 3PW761 3PW771 3PW831 3PW851 - PW856 1PX071 1PX701 1PY001 - PY008 1PY021 - PY022 1PY031 1PY036 - PY037 1PY046 - PY048 1PY051 - PY053 1PY056 - PY057 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 21 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 22 GroupVariable Number 1PY101 - PY103 1PY111 - PY113 1PY131 - PY135 1PY141 - PY143 1PY151 - PY154 1PY156 - PY157 1PY161 - PY162 1PY166 1PY191 1PY201 1PY221 - PY222 1PY231 1PY241 - PY244 1PY270 - PY275 1PY281 1PY286 1PY301 - PY304 1PY321 - PY323 1PY341 - PY346 1PY361 - PY362 1PY381 1PY401 1PY409 - PY411 1PY421 - PY422 1PY441 1PY451 1PY461 - PY463 1PY591 - PY595 1PY611 - PY612 1PY621 1PY631 1PY651 1PY671 - PY672 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 22 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 23 GroupVariable Number 1PY721 1PY741 2. Spares Affected None. B. Concurrent Requirements The intercostal inspections between STA 348.2 and STA 360 in the service bulletin listed below must be done at the same time as this service bulletin: DescriptionService BulletinCompany STA 360 to STA 348.2 and STA 303.9 to STA 294.5, Stringers S-7L - S-16L, Left Side, Intercostal Inspection, Repair and Modifica- tion 737-53A1204, Revision 2Boeing C. Reason This service bulletin gives instructions to inspect the Station (STA) 348.2 frame for cracks under the stop fittings. This service bulletin also gives instructions to inspect for missing fasteners common to the STA 348.2 frame at S-7L through S-15L. Undetected or remaining cracks in the frame will propagate by normal fatigue due to cyclic cabin pressure loading. If cracks continue to propagate, the stop fittings will become ineffective. This can result in a possible rapid decompression and a potential separation of the forward entry door from the aircraft. Boeing has received reports of cracks in the STA 348.2 frame on six 737-200 cargo airplanes. The STA 348.2 frame is a body frame aft of the forward entry door cutout. The cracks were located under the stop fittings at Stringer 15L and 16L. Since the release of the original issue of this service bulletin, Boeing has received reports of STA 348.2 frame cracking at S-15L above the two outboard fasteners attaching the frame inner chord and door stop fitting. The cracking was reported on seven passenger airplanes that had accumulated between 19,185 and 64,800 flight cycles. Spares history also shows that seventeen frame chords have been ordered in the last ten years. Cracks have also been found in the outboard chord at S-16L. Boeing has received reports of ten passenger airplanes with missing fasteners in the STA 348.2 frame inner chord at stringer S-7L through S-15L. Boeing Service Related Problem (SRP) 737-SRP-53-0149 and 737-SRP-53-0306 are related to this service bulletin. Revision 1 is sent to add all 737-100/200/300/400/500 series airplanes to the service bulletin effectivity and to remove intercostal inspections from the Service Bulletin. Intercostal Inspections between STA 348.2 and STA 360 are now covered in Service Bulletin 737-53A1204, Revision 2. These sections are changed: BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 23 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 24 1. Added 737-100/200 airplanes, line numbers 1-32 to new Group 2 in Paragraph 1.A., Effectivity. 2. Added 737-200/300/400/500 airplanes, line numbers 33-3132 to new Group 3 in Paragraph 1.A., Effectivity. 3. Added Service Bulletin 737-53A1204, Revision 2 intercostal inspections to Paragraph 1.B., Concurrent Requirements. 4. Added new service history information to Paragraph 1.C., Reason. 5. Added instructions for new Group 2 and 3 airplanes and added Maintenance Zone Tables to Paragraph 1.D., Description. 6. Added Compliance Table 2 and 3 for new Group 2 and 3 airplanes to Paragraph 1.E., Compliance. 7. Added Damage Tolerance Based Structural Inspections statement to Paragraph 1.K., Publications Affected. 8. Added kit pricing and availability for new Kits 65C38828-1, 65C38828-2 and 65C39000-1 to Paragraph 2.A., Material - Price and Availability. 9. Added new Fastener Kit 65C38828-1 for new Group 2 and 3 airplanes and added new Replacement Parts Kits 65C38828-2 and 65C39000-1 for new Group 3 airplanes to Paragraph 2.C., Parts Necessary for Each Airplane. 10. Removed the intercostal inspection from Paragraph 3.B., Work Instructions and FIGURE 3 for Group 1 airplanes. 11. Added Part 2 - Access, Part 3 - Inspection and Part 5 - Close Access for new Group 2 and 3 airplanes to Paragraph 3.B., Work Instructions. 12. Added Part 4 - Repair, for new Group 3 airplanes to Paragraph 3.B., Work Instructions. 13. Added optional NDT inspection reference to FIGURE 3. 14. Added FIGURE 6, FIGURE 7 and FIGURE 21 for access, inspection and close access for the new Group 2 and 3 airplanes. 15. Added FIGURE 9 through FIGURE 20 for the repair of the frame inner chord, reinforcement angle, stringer S-14L, S-15L and S-16L intercostals in Part 4 - Repair, for the new Group 3 airplanes. 16. Added FIGURE 8 for inspections for missing fasteners in the STA 348.2 frame inner chord adjacent to the door stop at stringer S-7L through S-15L for the new Group 2 and 3 airplanes. D. Description Group 1: Gain access to the stop fittings at stringers S-14L, S-15L, and S-16L on the STA 348.2 frame. Remove the forward entry door reveal, scuff plate, cover plate, and lining support. Remove the stop fittings at stringers S-14L, S-15L, and S-16L. Eddy current inspect the STA 348.2 frame inner chord over a 4.00 inch length centered on the removed stop fittings. Eddy current rotary probe inspect the stop fitting holes. Remove the lower inner skin between STA 360 and STA 348.2 to gain access to the aft side of the STA 348.2 frame. If any crack is found, contact Boeing for repair instruction and do the repair. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 24 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 25 Group 2-3: Remove the forward entry door reveal, scuff plate, cover plate, and lining support. Remove the stop fittings at stringers S-14L, S-15L and S-16L. Do a detailed inspection and an eddy current inspection of the STA 348.2 frame inner chord over a 4.00 inch length centered on the removed stop fittings at S-15L and S-16L. Do an open hole eddy current inspection of the frame common to the stop fitting holes. Remove the shear web between STA 351.2 to STA 348.2 to get access to the aft side of the STA 348.2 frame. Do an open hole eddy current inspection of the fastener holes in the shear web. Do a detailed inspection of the frame outer chord, frame inner chord and reinforcement angle. Group 2: If any crack is found, contact Boeing for repair instruction and do the repair. Group 3: If any crack is found in the STA 348.2 frame outer chord, contact Boeing for repair instruction and do the repair. If any crack is found in the STA 348.2 frame inner chord, reinforcement angle or the shear web, do the repair in accordance with Paragraph 3.B., Work Instructions of this service bulletin. If cracks are found in the S-14L, S-15L, and S-16L doorstop intercostals as a result of SB 737-53A1204R2 inspection, repair in accordance with Accomplishment Instructions Paragraph 3.B.4. Part 4 - Repair. Group 2-3: Do a detailed inspection of the STA 348.2 frame for missing fasteners at stringers S-7L through S-15L. If any fastener is missing, contact Boeing and do the work instructed by Boeing. The work in this service bulletin is done in the maintenance zone(s) given below. Group 1: Affected Maintenance Zones ZoneModel 1-5, 1-7737-200, 737-200C Group 2-3: Affected Maintenance Zones ZoneModel 1-5, 1-7737-100, 737-200 Group 3: Affected Maintenance Zones ZoneModel 105, 107737-300, 737-400, 737-500 E. Compliance Federal Aviation Administration (FAA) Airworthiness Directives 98-11-04 R1, 2008-08-23 and 2008-09-13 are related to this service bulletin. FAA Airworthiness Directive 2004-09-09 mandates the original issue of this service bulletin. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 25 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 26 The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to Revision 1 of this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in Revision 1 of this service bulletin mandatory. Group 1: Table 1: STA 348.2 Frame Inspection for Cracks Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) ActionCondition 6,000 Flight Cy- cles. Within 2,250 Flight Cycles af- ter the original issue date of this Service Bul- letin. Before 46,000 Total Flight Cy- cles. Do eddy current inspections for cracking of the frame in accor- dance with Paragraph 3.B., Work Instructions, Part 1. Do a detailed inspection for cracking of the frame inner chord and outer chord in accordance with Para- graph 3.B., Work Instructions, Part 1. All Airplanes -Before Further Flight.Contact Boeing for repair instruc- tions and do the repair. Crack(s) found. Group 2: Table 2: STA 348.2 Frame Inspection for Cracks and Missing Fasteners Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) ActionCondition -Within 4,500 Flight Cycles after the Revision 1 date of this Service Bulletin. Do an inspection for missing fasteners in ac- cordance with Paragraph 3.B., Work Instructions, Step 3.B.3.a. All Airplanes -Before Further Flight.Contact Boeing for repair information and do the repair. If any fastener is missing. 6,000 Flight Cy- cles. Within 4,500 Flight Cycles af- ter the Revision 1 date of this Service Bulletin. Before 15,000 Total Flight Cy- cles. Do eddy current inspec- tions for cracking of the frame, reinforcement an- gle, and shear web in ac- cordance with Paragraph 3.B., Work Instructions, Step 3.B.3.b. Do a de- tailed inspection for cracking of the STA 348.2 frame outer chord, inner chord and reinforcement angle in accordance with Paragraph 3.B., Work In- structions, Step 3.B.3.b. All Airplanes BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 26 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 27 Group 2: Table 2: STA 348.2 Frame Inspection for Cracks and Missing Fasteners Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) ActionCondition -Before Further Flight.Contact Boeing for repair instructions and do the repair. Crack(s) found. Group 3: Table 3: STA 348.2 Frame Inspection for Cracks and Missing Fasteners Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) ActionCondition -Within 4,500 Flight Cycles after the Revision 1 date of this Service Bulletin. Do an inspection for missing fasteners in ac- cordance with Paragraph 3.B., Work Instructions, Step 3.B.3.a. All Airplanes -Before Further Flight.Contact Boeing for repair information and do the repair. If any fastener is missing. 6,000 Flight Cy- cles. Within 4,500 Flight Cycles af- ter the Revision 1 date of this Service Bulletin. Before 15,000 Total Flight Cy- cles. Do eddy current inspec- tions for cracking of the frame, reinforcement an- gle, and shear web in ac- cordance with Paragraph 3.B., Work Instructions, Step 3.B.3.b. Do a de- tailed inspection for cracking of the STA 348.2 frame outer chord, inner chord and reinforcement angle in accordance with Paragraph 3.B., Work In- structions, Step 3.B.3.b. All Airplanes -Before Further FlightContact Boeing for repair instructions and do the repair. Crack(s) found in the frame outer chord. (a)Before Further FlightReplace the cracked part in accordance with Para- graph 3.B., Work Instruc- tions, Part 4. Crack(s) found in the frame inner chord, reinforcement angle or shear web. (a) Replacement of the cracked part does not terminate the repeat inspections. Continue the inspections in accordance with Paragraph 3.B., Work Instructions, Step 3.B.3.b. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 27 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 28 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 Seattle Aircraft Certification Office approves the repair procedures and the inspection methods with the corresponding compliance times specified in Tables 1 through 3, Section 1.E., "Compliance," of Service Bulletin 737-53A1240, Revision 1, as an alternative method of compliance to the repair procedures and the inspection methods with the corresponding compliance times specified in paragraphs (a) and (b) of AD 2004-09-09. When this service bulletin specifies contacting Boeing for repair instructions, the repair instructions must be approved by the FAA in accordance with paragraph (b) of the AD. All provisions of AD 2004-09-09 that are not specifically referenced in the preceding paragraph remain fully applicable and must be complied with. For 737-100/-200 airplanes identified in the Revision 1 of the service bulletin, the repair and/or modification of this service bulletin, Revision 1, have been reviewed as required by paragraph (g) of Airworthiness Directive (AD) 98-11-04 R1. The repair and/or modification is found to not create a Structurally Significant Item (SSI) or affect an existing SSI in Supplemental Structural Inspection Document (SSID) D6-37089, Rev D. SSID inspections remain effective with the repair and/or modification installed. Do the existing SSID inspections as required per paragraph (b) and (c) of AD 98-11-04 R1. For 737-200C airplanes identified in the Revision 1 of the service bulletin, the repair and/or modification of this service bulletin, Revision 1, have been reviewed as required by paragraph (i)(2) of Airworthiness Directive (AD) 2008-08-23. The repair and/or modification is found to not create a Structurally Significant Item (SSI) or affect an existing SSI in Supplemental Structural Inspection Document (SSID) D6-37089, Rev E. SSID inspections remain effective with the repair and/or modification installed. Do the existing SSID inspections as required per paragraph (g) and (h) of AD 2008-08-23. For 737-300/-400/-500 airplanes identified in the Revision 1 of the service bulletin, the repair and/or modification of this service bulletin, Revision 1, have been reviewed as required by paragraph (i)(2) of Airworthiness Directive (AD) 2008-09-13. The repair and/or modification is found to not create a Structurally Significant Item (SSI) or affect an existing SSI in Supplemental Structural Inspection Document (SSID) D6-82669. SSID inspections remain effective with the repair and/or modification installed. Do the existing SSID inspections as required per paragraph (g) and (h) of AD 2008-09-13. G. Manpower The table below shows an estimate of the task-hours necessary to do this inspection for each airplane. This estimate is for direct labor only, done by an experienced crew. Adjust the estimate with operator task-hour data if necessary. The estimate does not include lost time. These are some examples of lost time: BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 28 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 29 — 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: Elapsed HoursTask-HoursNumber of PersonsTask 111Open Access 9182Remove/Inspect/Install 111Close Access 1120TOTAL FOR EACH AIRPLANE Group 2: Elapsed HoursTask-HoursNumber of PersonsTask 1.503.002Open Access 2.252.251FIGURE 6 3.507.002FIGURE 7 1.001.001FIGURE 8 4.254.251FIGURE 21 1.503.002Close Access 14.0020.50TOTAL FOR EACH AIRPLANE Group 3: Access, Inspection and Close Access Elapsed HoursTask-HoursNumber of PersonsTask 2.254.502Access 2.252.251FIGURE 6 3.507.002FIGURE 7 1.001.001FIGURE 8 4.254.251FIGURE 21 2.254.502Close Access 14.0023.50TOTAL FOR EACH AIRPLANE BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 29 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 30 Group 3: Part 4 - Repair Elapsed HoursTask-HoursNumber of PersonsTask 1.501.501FIGURE 9 2.252.251FIGURE 10 2.002.001FIGURE 11 2.002.001FIGURE 12 2.502.501FIGURE 13 2.502.501FIGURE 14 1.001.001FIGURE 15 2.002.001FIGURE 16 2.252.251FIGURE 17 1.001.001FIGURE 18 2.752.751FIGURE 19 1.501.501FIGURE 20 23.2523.25TOTAL FOR EACH AIRPLANE H. Weight and Balance Changes Group 1: Change in Moment (Pound-Inches) Change in Weight (Pounds) Airplane +0Negligible737-200C Group 2-3: Change in Moment (Pound-Inches) Change in Weight (Pounds) Airplane NegligibleNegligible737-100 NegligibleNegligible737-200 NegligibleNegligible737-300 NegligibleNegligible737-400 NegligibleNegligible737-500 I. Electrical Load Data Not applicable. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 30 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 31 J. References 1. Existing Data: a. Engineering Change Memo PRR 35005-246RS and Engineering Change Memo PRR 35005-287RS b. Service Related Problem (SRP) 737-53-0306 and SRP 737-53-0149 c. Federal Aviation Administration (FAA) Airworthiness Directive 98-11-04 R1, 2004-09-09, 2008-08-23, 2008-09-13 d. Boeing Drawing 65-88700 e. Boeing Parts Standard Document D-590 f. Boeing Service Bulletin 737-53A1204 g. Boeing Service Letter 737-SL-51-042 h. Standard Overhaul Practices Manual (SOPM) 20-30-02, 20-41-02, 20-41-05, 20-50-09, 20-50-12, 20-50-19 i. 737 Non-Destructive Testing (NDT) Manual Part 6, 51-00-00, Figure 4, Figure 16 and Figure 23. j. 737-100/200 Aircraft Maintenance Manual (AMM) 25-21-21, 25-21-41, 25-21-51, 25-24-111, 25-24-171, 25-27-100 k. 737-100/200 Structural Repair Manual (SRM) 51-30-01, 53-10-10 l. 737-300/400/500 Aircraft Maintenance Manual (AMM) 25-21-31, 25-21-39, 25-21-46, 25-21-71, 25-22-00, 25-24-15, 25-24-72, 25-27-15, 25-31-41, 25-40-01 m. 737-300 Structural Repair Manual (SRM) 51-30-01, 53-10-04 n. 737-400 Structural Repair Manual (SRM) 51-30-01, 53-10-04 o. 737-500 Structural Repair Manual (SRM) 51-30-01, 53-10-04 2. Data supplied with this Service Bulletin: None. 3. Installation Drawings Used in the Preparation of this Service Bulletin: Group 1: NotesTitleDrawing Number Door Instl - Forward Entry50-07945 Reveal Instl - Forward Entry Door, STA 348.2065-03359 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 31 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 32 Group 1: NotesTitleDrawing Number Frame Instl - Body STA 351.265-45817 Frame and Intercostal Instl - Body STA 36065-54960 Frame Instl - STA 348.2065-54961 Support Instl - FWD Entry Doorway Lining65-49632 Group 2-3: NotesTitleDrawing Number Door Instl - Forward Entry50-07945 Reveal Instl - Forward Entry Door, STA 348.2065-03359 Frame Instl - Body STA 351.265-45817 Frame Instl - STA 348.2065-17685 Sill Instl - Lower, Forward Entry Door65-17688 Skin and Stringer Instl - Section 4165-45800 Mechanism Instl - Latch, Forward Entry Door, Airstair65-45889 Frame Instl - STA 36065-58280 These drawings were used to prepare this service bulletin. These drawings are not necessary to make the specified changes, and are not supplied with this service bulletin. These drawings may not be applicable to all airplane configurations or operators. K. Publications Affected 1. Publications: None. 2. Damage Tolerance Based Structural Inspections: Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the Maintenance Program. This service bulletin affects FCS but no new DTIs are necessary. L. Interchangeability and Intermixability of Parts Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 32 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 33 2. MATERIAL INFORMATION A. Material - Price and Availability Boeing can supply the kits shown in Paragraph 2.C., Parts Necessary for Each Airplane as shown below. If there is a limit to the quantity (QTY) of available kits, a supply sequence is given by Spares. More kits become available as shown in the Reorder Lead Time (ROLT). ROLT is calculated from the date Boeing gets the purchase order. Group 1: Unit Price thru October 31, 2010 ROLT (Weeks) QTYDateNameKit Number $ 476.0087--Fastener Kit - Inspection Close Up 65C37852-97 Group 2-3: Unit Price thru October 31, 2010 ROLT (Weeks) QTYDateNameKit Number $ 12.00435010/12/09Fastener Kit - Inspection Close Up 65C38828-1 $ 12.00435010/26/09 $ 12.00435011/09/09 $ 12.00435011/23/09 $ 12.00435012/09/09 $ 12.00435012/23/09 $ 12.00435001/15/10 $ 12.00435001/29/10 Group 3: Unit Price thru October 31, 2010 ROLT (Weeks) QTYDateNameKit Number $ 9,628.00442511/23/09Intercostal Repair Kit65C38828-2 $ 9,628.00442512/09/09 $ 9,628.00442512/23/09 $ 9,628.00442501/08/10 $ 9,628.00442501/15/10 $ 9,628.00442501/22/10 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 33 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 34 Group 3: Unit Price thru October 31, 2010 ROLT (Weeks) QTYDateNameKit Number $ 2,216.00715010/12/09Repair Kit - S-16L Inter- costal 65C39000-1 $ 2,216.00715010/26/09 $ 2,216.00715011/09/09 $ 2,216.00715011/23/09 $ 2,216.00715012/09/09 The kits/parts are subject to the terms and conditions of the Boeing standard purchase order acknowledgment. After the Unit Price date, new price data is applicable. Prices are in United States dollars. Terms: Net 30 days. Reference this service bulletin and submit your purchase order by one of the methods that follow: 1. Order on-line via ATA Spec 2000 or Boeing Part Page 2. Fax to (206) 662-7145 3. Spares Customer Support - MC 36-65 Boeing Spares Department P.O. Box 3707 Seattle, Washington 98124-2207 B. Industry Support Information Boeing warranty remedies are not available for the inspection and/or repair procedures given in this service bulletin. C. Parts Necessary For Each Airplane 1. Kits/Parts: To get the kits/parts shown below, refer to Paragraph 2.A., Material - Price and Availability. NOTE: Group 1: One top kit and the items shown in Paragraph 2.C.2., Parts and Materials Supplied by the Operator, are necessary for each airplane. Group 2: One top kit (fastener kit - inspection close up) and the items shown in Paragraph 2.C.2., Parts and Materials Supplied by the Operator, are necessary for each airplane. Group 3: Three top kits (one fastener kit and two repair kits) and the items shown in Paragraph 2.C.2., Parts and Materials Supplied by the Operator, are necessary for each airplane. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 34 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 35 – The 65C38828-1 fastener kit is required for close access. – The 65C38828-2 kit contains the frame inner chord and parts with a known crack history common to the S-14L intercostal, the S-15L intercostal and the S-16L intercostal between STA 348.2 and STA 351.2. Individual parts can be ordered separately. – The 65C39000-1 kit contains the parts to repair the S-16L intercostal between STA 351.2 and STA 360. Group 1: 65C37852 Fastener Kit NotesNameQTYNew Part Number -97 (b)Bolt2BACB30LH3-11 (b)Bolt1BACB30LH3-3 (b)Bolt5BACB30LH3-4 (b)Bolt8BACB30LH3-5 (b)Bolt3BACB30LH3-6 (b)Bolt1BACB30LH3-9 (b)Bolt2BACB30LK3-10 (b)Bolt1BACB30LK3-6 (b)Bolt - 1/32 O.S.5BACB30NM3K4Y (b) (c)Bolt4BACB30ZE3-10 (a)Nut78BACN10JC3CD (a)Nut29BACN10JC4CD Nut3BACN10MT3X Washer3BACW10AU4 (a)Washer58BACW10BP3CD (a)Washer - 1/32 O.S.11BACW10BP32CD (a)Washer74BACW10BP3DP (a)Washer - 1/32 O.S.9BACW10BP32DP (a)Washer33BACW10BP4CD (a)Washer29BACW10BP4DP Nut5NAS1805-3L (b)Bolt3NAS6703-10 (b)Bolt6NAS6703-4 (b)Bolt16NAS6703-5 (b)Bolt6NAS6703-6 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 35 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 36 Group 1: 65C37852 Fastener Kit NotesNameQTYNew Part Number -97 (b)Bolt - 1/32 O.S.2NAS6703-6Y (b)Bolt10NAS6703-7 (b)Bolt - 1/32 O.S.1NAS6703-7Y (b)Bolt6NAS6703-8 (b)Bolt - 1/32 O.S.1NAS6703-8Y (b)Bolt2NAS6703-9 (b)Bolt12NAS6704-4 (b)Bolt16NAS6704-5 (b)Bolt1NAS6704-8 (b)Bolt1NAS6704-9 (b) (c)Bolt4NAS8703-10 (b)Bolt4NAS8703-5 (b)Bolt4NAS8703-6 (b)Bolt6NAS8703-7 (b)Bolt - 1/32 O.S.1NAS8703-7Y (b)Bolt1NAS8703-8 (b)Bolt2NAS8703-9 (b)Bolt1NAS8704-9 (a) There are more parts than are necessary (b) If grip length shown is not available at Boeing, fasteners supplied in kits may be one grip length longer than indicated. Also, if any fasteners part numbers listed are not available or have been superseded, substitute fasteners may be supplied in kits. Boeing Document D-590 and Boeing Drawing 65-88700 are used to determine the part numbers used as substitutes. (c) NAS8703-10 is optional to BACB30ZE3-10. Group 2-3: Kit 65C38828 - Fastener Kit - Inspection Close Up NotesNameQTYNew Part Number -1 KIT-65C38828-1 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 36 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 37 Group 2-3: Kit 65C38828 - Fastener Kit - Inspection Close Up NotesNameQTYNew Part Number -1 (a) For Latch Plate installation in FIGURE 19. Not required for Inspec- tion only. BOLT, 100 DEG HEX DR3BACB30NW6K5X (a)BOLT, 100 DEG HEX DR6BACB30NW6K8X (a)BOLT, PROTRUDING HD2BACB30NX6K6X 3 Collars for Latch Plate installation in FIGURE 19. Not required for In- spection only. COLLAR11BACC30M6 (a)RIVET, UNIVERSAL HD11BACR15FT5D6C (a)RIVET, UNIVERSAL HD4BACR15FT5D7C (a)RIVET2BACR15FT5D8C (a)RIVET, UNIVERSAL HD1BACR15FT5D9C (a)RIVET, UNIVERSAL HD4BACR15FT6D10C (a)RIVET, UNIVERSAL HD2BACR15FT6D7C (a)RIVET, UNIVERSAL HD4BACR15FT6D8C (a)RIVET, UNIVERSAL HD2BACR15FT6D9C (a) If grip length shown is not available at Boeing, fasteners supplied in kits may be one grip length longer than indicated. Also, if any fasteners part numbers listed are not available or have been superseded, substitute fasteners may be supplied in kits. Boeing Document D-590 and Boeing Drawing 65-88700 are used to determine the part numbers used as substitutes. Group 3: Kit 65C38828 - Frame and Intercostal Repair Kit NotesExisting Part Number NameQTYNew Part Number -2 -KIT-65C38828-2 65-17685-37CHORD165-17685-37 65-17685-38WEB-SHEAR165-17685-38 65-17685-7ANGLE REINF165-17685-7 65-17685-9WEB-SHEAR165-17685-9 65-61777-505CHANNEL165-61777-505 65-61777-7CHANNEL165-61777-7 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 37 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 38 Group 3: Kit 65C38828 - Frame and Intercostal Repair Kit NotesExisting Part Number NameQTYNew Part Number -2 69-16509-6CLIP-ANGLE169-16509-6 69-16970-503CLIP ANGLE169-16970-503 69-16970-7CLIP ANGLE169-16970-7 69-26555-2CLIP-ANGLE169-26555-2 69-26555-3CLIP-ANGLE169-26555-3 69-48985-501CHANNEL169-48985U16 (a)-BOLT, 100 DEG HEX DR1BACB30NW6K3X (a)-BOLT, 100 DEG HEX DR12BACB30NW6K4X (a)-BOLT, 100 DEG HEX DR5BACB30NW6K5X (a)-BOLT, PROTRUDING HD2BACB30NX6K2 (a)-BOLT, PROTRUDING HD4BACB30NX6K2X (a)-BOLT, PROTRUDING HD6BACB30NX6K3X (a)-BOLT, PROTRUDING HD4BACB30NX6K4X (a)-BOLT4BACB30NX6K5 (a)-BOLT, PROTRUDING HD9BACB30NX6K6X -COLLAR41BACC30M6 (a)-RIVET, 100 DEG2BACR15BA3D4C (a)-RIVET, 100 DEG2BACR15BA3D5C (a)-RIVET, 100 DEG4BACR15BA6D7C (a)-RIVET- BLIND5BACR15DR3AC3 (a)-RIVET8BACR15DR3AC4 (a)-RIVET2BACR15BB4D4C (a)-RIVET, UNIVERSAL HD22BACR15FT5D4C (a)-RIVET, UNIVERSAL HD30BACR15FT5D5C (a)-RIVET, UNIVERSAL HD7BACR15FT5D6C (a)-RIVET, UNIVERSAL HD2BACR15FT6D4C (a)-RIVET7BACR15FT6D5C (a)-RIVET, UNIVERSAL HD25BACR15FT6D6C (a)-RIVET, UNIVERSAL HD6BACR15FT6D7C (a)-RIVET, UNIVERSAL HD3BACR15FT6D8C BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 38 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 39 Group 3: Kit 65C38828 - Frame and Intercostal Repair Kit NotesExisting Part Number NameQTYNew Part Number -2 (a)-RIVET, UNIVERSAL HD2BACR15FT8D6C (a)-RIVET, UNIVERSAL HD9BACR15FT8D7C (a)-RIVET5BACR15GF5D5 (a)-RIVET, 100 DEG2BACR15GF6D6 (a)-RIVET, 100 DEG22BACR15GF6D7 (a)-RIVET, 100 DEG4BACR15GF6D8 (a) If grip length shown is not available at Boeing, fasteners supplied in kits may be one grip length longer than indicated. Also, if any fasteners part numbers listed are not available or have been superseded, substitute fasteners may be supplied in kits. Boeing Document D-590 and Boeing Drawing 65-88700 are used to determine the part numbers used as substitutes. Group 3: Kit 65C39000 - Repair Kit - S-16L Intercostal NotesExisting Part Number NameQTYNew Part Number -1 -KIT - FUSELAGE STA 348.2 S-16L INTERCOSTAL -65C39000-1 65-61777-5CHANNEL165-61777-5 69-16509-11 or 69- 16509-14 TEE165C37023-1 69-26555-4CLIP - ANGLE169-10056-1 -FILLER169-87926-1 -WEB169-87927-1 65-17685-6 or 65C37797-1 STRAP169-87927-2 (a)-BOLT, PROTRUDING HD1BACB30MY8K7Y (a)-BOLT, 100 DEG HEX DR4BACB30NW6K4X (a)-BOLT, 100 DEG HEX DR4BACB30NW6K5X (a)-BOLT, 100 DEG HEX DR1BACB30NW6K6X (a)-BOLT, PROTRUDING HD6BACB30NX6K2X (a)-BOLT, PROTRUDING HD8BACB30NX6K3X BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 39 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 40 Group 3: Kit 65C39000 - Repair Kit - S-16L Intercostal NotesExisting Part Number NameQTYNew Part Number -1 (a)-BOLT, PROTRUDING HD5BACB30VT5HK2 (a)-BOLT, PROTRUDING HD4BACB30VT5HK3 (a)-BOLT, PROTRUDING HD12BACB30VT5HK4 (a)-BOLT, PROTRUDING HD5BACB30VT6K2 (a)-BOLT, PROTRUDING HEAD7BACB30VT6K3 (a)-BOLT4BACB30VT6K4 (a)-BOLT2BACB30VT6K5 -COLLAR, SHEAR21BACC30BS5 -COLLAR18BACC30BS6 -COLLAR23BACC30M6 -COLLAR1BACC30R8 -FILLER, RECTANGULAR1BACF3H08RF010HN (a)-RIVET, UNIVERSAL HD8BACR15FT5D4C (a)-RIVET, 100 DEG5BACR15GF5D6 (a)-RIVET, SOLID1MS20615-6MP7 (a)-RIVET, SOLID1MS20615-6MP8 -GROMMET2NAS557-28C (a) If grip length shown is not available at Boeing, fasteners supplied in kits may be one grip length longer than indicated. Also, if any fasteners part numbers listed are not available or have been superseded, substitute fasteners may be supplied in kits. Boeing Document D-590 and Boeing Drawing 65-88700 are used to determine the part numbers used as substitutes. 2. Parts and Materials Supplied by the Operator: Group 1: NotesNameQTYPart Number / Specification (a) (c)Sealant16 ozBMS 5-95, Class B-1/2, -2, or -4 (b) (c)Corrosion Inhibiting Compound8 ozBMS 3-23 (a) Refer to SOPM 20-50-19. (b) Refer to SOPM 20-41-05. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 40 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 41 Group 1: NotesNameQTYPart Number / Specification (c) See the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier data. Group 2: NotesNameQTYPart Number / Specification (a)Sealant16 ozBMS 5-95, Class B-1/2, -2, or -4 (a)Corrosion Inhibiting Compound8 ozBMS 3-23 (a)Primer2 ozBMS 10-11, Type 1 (a) See the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier data. Group 3: NotesNameQTYPart Number / Specification (a)Sealant16 ozBMS 5-95, Class B-1/2, -2, or -4 (a)Adhesive2 ozBMS 5-105, Type 5 or 6 (a)Corrosion Inhibiting Compound8 ozBMS 3-23 (a)Primer2 ozBMS 10-11, Type 1 (a) See the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier data. 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. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 41 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 42 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 42 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT BLANK PAGE ### Page 43 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. The instructions identified in Paragraph 3.B., Work Instructions and the Figure(s) give the recommended sequence of steps. The sequence of steps to do this service bulletin can be changed. 2. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for definition of the acronyms. 3. Obey all of the warnings and cautions given in the specified manual sections. 4. 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 are in 737 SRM, Chapter 51 – Torque limits to tighten nuts and bolts are in 737 SRM, Chapter 51 – Minimum rivet and bolt edge margin is 1.7D. 5. Use the approved fastener and process material substitutions in accordance with 737 SRM, Chapter 51. Alternate fasteners are listed in 737 SRM Chapter 51 and Boeing Drawing 65-88700. 6. If the length of any fastener specified in this service bulletin does not meet the installation standards in SRM Chapter 51, then a fastener of the same specification, or an approved substitute, with a length which meets the installation standards in SRM Chapter 51 may be used. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 43 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 44 7. 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. 8. These work instructions refer to procedures included in other Boeing documents. When the words "refer to" are used and the operator has an accepted alternative procedure, the accepted alternative procedure can be used. When the words "in accordance with" are included in the instruction, the procedure in the Boeing document must be used. 9. Boeing Service Letter 737-SL-51-042, 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. B. WORK INSTRUCTIONS 1. Group 1: PART 1 - Inspection a. Remove the scuff plate, reveal, lining support, and cover plate, of the forward entry door to gain access to the aft stop fittings at stringers S-14L, S-15L, and S-16L, in accordance with FIGURE 1. b. Remove the stop fittings at stringers S-14L, S-15L, and S-16L and remove the lower inner skin between STA 360 and STA 348.2, in accordance with FIGURE 2. c. Do a detailed inspection of the frame inner chord and outer chord for cracks. Do an eddy current surface inspection of a 4.0 inch length centered on the location of the removed stop fittings common to S-15L and S-16L. Do an eddy current open hole inspection of the frame at the door stop fitting attachment fastener holes. Accomplish the above inspections in accordance with FIGURE 3. (1) If any crack is found, contact Boeing for repair instructions and do the repair. (2) If no crack is found, repeat the inspections in accordance with Paragraph 1.E., Compliance. d. Install the removed stop fittings, lining support, reveal, cover plate, and scuff plate, in accordance with FIGURE 4 and FIGURE 5. NOTE: The holes for attaching the stop fittings and the lower skin are to be oversized to class one hole tolerances at the first inspection. This will allow removable bolts to be installed. Do not oversize the holes at subsequent inspections. e. Return the airplane to a serviceable condition. f. Repeat the inspections in accordance with Paragraph 1.E., Compliance. 2. Group 2-3: PART 2 - Access BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 44 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 45 a. Remove the following equipment if installed as necessary to get access to the area between Stringers S-7L to S-16L and between Frame Stations STA 348.2 to STA 360: (1) Remove the number 7 galley, if necessary. Refer to 737-300/400/500 AMM 25-31-41 as an accepted procedure. (2) Remove the windscreen, if necessary. Refer to 737-100/200 AMM 25-24-111 or 737-300/400/500 AMM 25-24-15 as an accepted procedure. (3) Remove the coat closet, if necessary. Refer to 737-100/200 AMM 25-24-171 or 737-300/400/500 AMM 25-24-72 as an accepted procedure. (4) Remove the "F" modular lavatory unit, if necessary. Refer to 737-300/400/500 AMM 25-40-01 as an accepted procedure. (5) Remove the left side passenger seat units as necessary. Refer to 737-300/400/500 AMM 25-22-00 as an accepted procedure. (6) Remove the left side passenger cabin floor covering or carpets as necessary. Refer to 737-100/200 AMM 25-27-100 or 737-300/400/500 AMM 25-27-15 as an accepted procedure. (7) Remove the passenger cabin sidewall lining, forward entry doorway lining, lowered ceiling panels and insulation, as necessary. Refer to 737-100/200 AMM 25-21-21, 737-100/200 AMM 25-21-41 and 737-100/200 AMM 25-21-51 or 737-300/400/500 AMM 25-21-46, 737-300/400/500 AMM 25-21-31, 737-300/400/500 AMM 25-21-71 and 737-300/400/500 AMM 25-21-39 as accepted procedures. b. Remove the scuff plate, reveal, lining support, cover plate and aft door stop fittings at stringers S-14L, S-15L, and S-16L in accordance with FIGURE 6. 3. Group 2-3: PART 3 - Inspection a. Do a detailed inspection of the frame inner chord adjacent to the door stops at stringers S-7L through S-15L for missing fasteners in accordance with FIGURE 8. (1) If any fastener is missing, contact Boeing for repair information and do the repair. b. Do a detailed inspection of the frame (inner chord and outer chord) and reinforcement angle; high frequency eddy current (HFEC) inspection of the frame and reinforcement angle at the door stop fitting attachment holes; HFEC inspection of the shear web at the attachment holes; and a surface HFEC inspection of the frame, for cracks in accordance with FIGURE 7. (1) If no crack is found, do Part 5 - Close Access and repeat the inspections in accordance with Paragraph 1.E., Compliance. (2) Group 3: If any crack is found: (a) If any crack is found in the STA 348.2 frame inner chord, reinforcement angle or shear web, replace the cracked parts as necessary in accordance with Part 4 - Repair. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 45 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 46 NOTE: Replacement of the cracked part does not terminate repeat inspections. Continue to do the inspections at the intervals in accordance with Paragraph 1.E., Compliance. (b) If any crack is found in the STA 348.2 frame outer chord, contact Boeing for repair instructions and do the repair. (3) Group 2: If any crack is found, contact Boeing for repair instructions and do the repair. c. Repeat the inspections in accordance with Paragraph 1.E., Compliance. 4. Group 3: PART 4 - Repair NOTE: Part 4 - Repair can be used as applicable if any crack is found in the S-14L, S-15L or S-16L door stop intercostals as a result of the SB 737-53A1204 R2 inspection. Confirm that the airplane found with the crack in S-14L, S-15L, or S-16L door stop intercostals per the SB 737-53A1204 R2 inspection are within the Group 3 effectivity of this SB. If the airplane is not covered in the Group 3 effectivity of this SB, contact Boeing for repair instructions and do the repair. a. STA 348.2 frame inner chord and reinforcement angle repair: The following repair instructions are for cracks found on the inner chord and the reinforcement angle from the production splice just above S-14L to the floor. Although the repair instructions replace both parts, only cracked parts are required to be replaced. It is acceptable to re-use the uncracked part provided it has been HFEC inspected and is free of any crack indication. Verify the part is free of any crack by HFEC inspection of the fastener holes in accordance with 737 NDT Part 6, 51-00-00, Figure 16 and HFEC inspection of the part in accordance with 737 NDT Part 6, 51-00-00, Figure 4 or 23. (1) Remove the frame inner chord and reinforcement angle at STA 348.2 in accordance with FIGURE 9. (2) Do an open hole HFEC inspection of all opened fastener holes in all uncracked structures in accordance with 737 NDT Part 6, 51-00-00, Figure 16. (a) If any crack is found that cannot be repaired in accordance with this Service Bulletin, contact Boeing for repair details and do the repair. (3) Assemble the new frame inner chord and reinforcement angle in accordance with FIGURE 10. (4) Install the frame inner chord and reinforcement angle at STA 348.2 in accordance with FIGURE 19. (5) Do Part 5 - Close Access and continue the inspections in accordance with Part 3 - Inspection at the intervals given in accordance with Paragraph 1.E., Compliance. b. S-14L door stop intercostal repair: BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 46 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 47 The following repair instructions are for cracks found on the S-14L intercostal common to the clip (part number 69-48985-( )) and stringer splice (part number 65-61777-( )). Although the repair instructions replace both parts, only cracked parts are required to be replaced. It is acceptable to re-use the undamaged part provided it has been inspected in accordance with the Accomplishment Instructions of SB 737-53A1204 R2 and is free of any crack indication. NOTE: Adjust the removal instructions in FIGURE 11 accordingly to remove only the damaged parts. (1) Remove and discard the cracked S-14L intercostal parts between STA 348.2 and STA 360 in accordance with FIGURE 11. (2) Do an HFEC inspection of all opened fastener holes in all uncracked parts in accordance with 737 NDT Part 6, 51-00-00, Figure 16. (a) If any crack is found that cannot be repaired in accordance with FIGURE 12, contact Boeing for repair details and do the repair. (3) Install new S-14L intercostal parts between STA 348.2 and STA 360 as required in accordance with FIGURE 12. c. S-15L door stop intercostal repair: The following repair instructions are for cracks found on the two clip angles and the stringer splice indicated in FIGURE 14 as new parts. Although the repair instructions replace these parts together, only cracked parts are required to be replaced. It is acceptable to re-use the undamaged part provided it is inspected in accordance with the Accomplishment Instructions of SB 737-53A1204 R2 and is free of any crack indication. NOTE: Adjust the removal instructions in FIGURE 13 accordingly to remove only the damage parts. (1) Remove and discard the cracked S-15L intercostal parts between STA 348.2 and STA 360 in accordance with FIGURE 13. (2) Do an HFEC inspection of all opened fastener holes in all uncracked parts in accordance with 737 NDT Part 6, 51-00-00, Figure 16. (a) If any crack is found that cannot be repaired in accordance with FIGURE 14, contact Boeing for repair details and do the repair. (3) Install new S-15L intercostal parts between STA 348.2 and STA 360 as required in accordance with FIGURE 14. d. S-16L door stop intercostal between STA 351.2 and STA 360 repair: The following repair instructions are for cracks on parts indicated in Figure 16 for the S-16L door stop intercostal from BS 351.2 to BS 360. If the crack is found in areas other than the web, as an optional alternative to the FIGURE 17 repair, remove and replace the damaged part with a new identical production part. However, if the crack is found in the web, then the repair must be accomplished in accordance with FIGURE 17. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 47 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 48 NOTE: If the optional removal and replacement procedure is used, adjust the removal instructions in FIGURE 16 accordingly to remove and replace only the damage parts. (1) Remove and discard the S-16L intercostal parts between STA 351.2 and STA 360 in accordance with FIGURE 16. (2) Do an HFEC inspection of all opened fastener holes in all uncracked parts in accordance with 737 NDT Part 6, 51-00-00, Figure 16. (a) If any crack is found that cannot be repaired in accordance with FIGURE 17, contact Boeing for repair details and do the repair. (3) Install new S-16L intercostal parts and stringer splice between STA 351.2 and STA 360 in accordance with FIGURE 17. e. S-16L door stop intercostal between STA 348.2 and STA 351.2 repair: The following repair instructions are for cracks found on the S-16L door stop intercostal from BS 348.2 to BS 351.2. Although the repair instructions replace these parts together, only damaged parts are required to be replaced. It is acceptable to re-use the undamaged part provided it is inspected in accordance with the Accomplishment Instructions of SB 737-53A1204 R2 and is free of any crack indication. NOTE: Adjust the removal instructions in FIGURE 15 accordingly to remove only the damage parts. (1) Remove and discard the cracked S-16L intercostal parts between STA 348.2 and STA 351.2 in accordance with FIGURE 15. (2) Do an HFEC inspection of all opened fastener holes in all uncracked parts in accordance with 737 NDT Part 6, 51-00-00, Figure 16. (a) If any crack is found that cannot be repaired in accordance with FIGURE 18, contact Boeing for repair details and do the repair. (3) Install new S-16L intercostal parts between STA 348.2 and STA 351.2 in accordance with FIGURE 18. NOTE: Maintain 4-6D fastener spacing unless stated otherwise. f. Install a new shear web between STA 348.2 and STA 351.2 if required in accordance with FIGURE 20. 5. Group 2-3: PART 5 - Close Access a. Install the removed stop fittings, shear web, lining support, reveal, cover plate and scuff plate in accordance with FIGURE 21. b. Install passenger cabin equipment that was removed to get access to the inspection area: BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 48 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 49 (1) Install the passenger cabin sidewall lining, forward entry doorway lining, lowered ceiling panels and insulation, as necessary. Refer to 737-100/200 AMM 25-21-21, 737-100/200 AMM 25-21-41 and 737-100/200 AMM 25-21-51 or 737-300/400/500 AMM 25-21-46, 737-300/400/500 AMM 25-21-31, 737-300/400/500 AMM 25-21-71 and 737-300/400/500 AMM 25-21-39 as accepted procedures. (2) Install the left side passenger cabin floor covering or carpets if necessary. Refer to 737-100/200 AMM 25-27-100 or 737-300/400/500 AMM 25-27-15 as an accepted procedure. (3) Install the left side passenger seats if necessary. Refer to 737-300/400/500 AMM 25-22-00 as an accepted procedure. (4) Install galley number 7, if necessary. Refer to 737-300/400/500 AMM 25-31-41 as an accepted procedure. (5) Install the coat closet, if necessary. Refer to 737-100/200 AMM 25-24-171 or 737-300/400/500 AMM 25-24-72 as an accepted procedure. (6) Install the windscreen, if necessary. Refer to 737-100/200 AMM 25-24-111 or 737-300/400/500 AMM 25-24-15 as an accepted procedure. (7) Install the "F" modular lavatory unit, if necessary. Refer to 737-300/400/500 AMM 25-40-01 as an accepted procedure. c. Return the airplane to a serviceable condition. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1: June 29, 2010 49 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 50 (OCR) BOEING SERVICE BULLETIN 737-53A1240 ALERT ALERT This Figure applies only to: Group 1. 10000 00 00 S-14 4 REVEAL ~ S-15 (2) COVER PLATE S-16 1 LINING SUPPORT (3) SCUFF PLATE INBD → FWD V73395 FIGURE 1: STA 348.2 DOOR FRAME - OPEN ACCESS (SHEET 1 OF 2) Original Issue: April 10, 2003 Revision 1 June 29, 2010 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 50 of 155 ### Page 51 The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for this figure. MORE DATAQTYIDENTIFICATIONNAMETASKSTEP 165-49632Lining SupportRemove/Keep1 1-Cover PlateRemove/Keep2 --Attachment Fasteners 1-Scuff PlateRemove/Keep3 --Attachment Fasteners 165-3359RevealRemove/Keep4 --Attachment Fasteners FIGURE 1: STA 348.2 DOOR FRAME - OPEN ACCESS (SHEET 2 OF 2) BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1 June 29, 2010 51 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 52 (OCR) BOEING SERVICE BULLETIN 737-53A1240 ALERT ALERT This Figure applies only to: Group 1. STA 348.2 3 LATCH (5) FILLER 1 INNER SKIN INBD ' → FWD V73439 FIGURE 2: STOP FITTING AND INNER SKIN - REMOVAL (SHEET 1 OF 2) Original Issue: April 10, 2003 Revision 1 June 29, 2010 737-53A1240 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 52 of 155 ### Page 53 The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for this figure. MORE DATAQTYIDENTIFICATIONNAMETASKSTEP (a)165-54960-505Inner SkinRemove/Keep1 (a)190-7813-501Stop Fitting - S-14LRemove/Keep2 1BACS40R08B18 orShim BACS40R08C18 1BACS40R17A29Shim 1-LatchRemove/Keep3 3-Attachment Fasteners (a)169-51407-1 orStop Fitting - S-15LRemove/Keep4 69-51407-5 1BACS40R08B18 orShim BACS40R08C18 1BACS40R17A36Shim Aft side of frame at stringer 15L 165-54961-15Filler - Radius 165-54961-16Filler - Radius 165-54961-8FillerRemove/Keep5 (a)169-51407-2 orStop Fitting - S-16LRemove/Keep6 69-51407-6 1BACS40R08B18 orShim BACS40R08C18 1BACS40R17A36Shim 165-54961-7Filler Aft side of frame at stringer 16L 265-54961-12Filler - Radius (a) Serviceable bolts can be kept for re-installation. FIGURE 2: STOP FITTING AND INNER SKIN - REMOVAL (SHEET 2 OF 2) BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1 June 29, 2010 53 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 54 (OCR) BOEING SERVICE BULLETIN 737-53A1240 ALERT ALERT This Figure applies only to: Group 1. (2) HOLE • FRAME INNER CHORD S-14L FRAME OUTER CHORD 4.00 FRAME INNER ( CHORD - S-15L 1 HOLE 4.00 - S-16L 1 HOLE INBD * • FWD FIGURE 3: FRAME INSPECTION (SHEET 1 OF 2) Original Issue: April 10, 2003 Revision 1 June 29, 2010 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. ### Page 55 The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for this figure. MORE DATAQTYIDENTIFICATIONNAMETASKSTEP (a)--FrameInspect1 (b)10-HoleInspect2 (c)--FrameInspect3 (a) Eddy current inspect the frame inner chord over a 4.0 inch length centered on the removed stop fitting at Stringers 15L and 16L in accordance with 737 NDT Part 6, Subject 51-00-00, Figure 4, or 737 NDT Part 6, Subject 51-00-00 , Figure 23. (b) Eddy current open hole inspect the stop fitting holes at Stringers S-14L, S-15L, and S-16L in accordance with 737 NDT Part 6, Subject 51-00-00, Figure 16. (c) Do a detailed inspection of the frame (inner chord and outer chord) from S-13L to the floor for cracks. FIGURE 3: FRAME INSPECTION (SHEET 2 OF 2) BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1 June 29, 2010 55 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 56 (OCR) BOEING SERVICE BULLETIN 737-53A1240 ALERT ALERT This Figure applies only to: Group 1. 1X12 INBD → FWD →B V73642 FIGURE 4: STOP FITTING AND INNER SKIN - INSTALLATION (SHEET 1 OF 7) Original Issue: April 10, 2003 Revision 1 June 29, 2010 BOEING PROPRIETARY - 737-53A1240 Copyright © Unpublished Work - See page 1 for details. 56 of 155 ### Page 57 (OCR) BOEING SERVICE BULLETIN 737-53A1240 ALERT ALERT 45 ^ 230-8-14L WL -— & DOOR STOP 110 - L DOOR STOP WL -- S-15L 220 -45 75 --E DOOR STOP S-16L - -75 %5 "†8 →INBD A-A V73712 FIGURE 4: STOP FITTING AND INNER SKIN - INSTALLATION (SHEET 2 OF 7) Original Issue: April 10, 2003 Revision 1 June 29, 2010 BOEING PROPRIETARY - 737-53A1240 Copyright © Unpublished Work - See page 1 for details. 57 of 155 ### Page 58 (OCR) BOEING SERVICE BULLETIN 737-53A1240 ALERT ALERT dest 44% 4 4 4 4 48 15 45 85 45 B15 415 B/s 45 AI 18481 8 4 816 A% →FWD B—B V73635 FIGURE 4: STOP FITTING AND INNER SKIN - INSTALLATION (SHEET 3 OF 7) Original Issue: April 10, 2003 Revision 1 June 29, 2010 737-53A1240 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 58 of 155 ### Page 59 The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for this figure. MORE DATAQTYIDENTIFICATIONNAMETASKSTEP (a)--Frame/PartsClean1 (b) (c)190-7813-501Stop FittingInstall/Kept2 1BACS40R08B18 or BACS40R08C18 Shim 1BACS40R17A29Shim (c) Aft side of frame165-54961-15Filler - RadiusInstall/Kept3 (c) Aft side of frame165-54961-16Filler - RadiusInstall/Kept4 (c)165-54961-8FillerInstall/Kept5 (b) (c)169-51407-1 or 69- 51407-5 Stop FittingInstall/Kept6 1BACS40R08B18 or BACS40R08C18 Shim 1BACS40R17A36Shim (c) Aft side of frame265-54961-12Filler - RadiusInstall/Kept7 (c)165-54961-7Filler - RadiusInstall/Kept8 (b) (c)169-51407-2 or 69- 51407-6 Stop FittingInstall/kept9 (c)1BACS40R08B18 or BACS40R08C18 Shim (c)1BACS40R17A36Shim (b) (c)1-Latch MechanismInstall/Kept10 (b) (c)165-54960-505Inner SkinInstall/Kept11 (d)1 LayerBMS 3-23Corrosion Inhibiting Compound Apply12 (a) Remove sealant and corrosion inhibiting compound from structure and all removed parts. Do not remove protective finish from parts or structure. Refer to SOPM 20-30-02 as an accepted procedure. (b) Refer to fastener code table for fastener information (c) Install all parts wet with BMS 5-95 sealant between mating surfaces. (d) Refer to SOPM 20-41-05 as an accepted procedure. FIGURE 4: STOP FITTING AND INNER SKIN - INSTALLATION (SHEET 4 OF 7) BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1 June 29, 2010 59 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT ### Page 60 The codes shown below agree with the letter shown in the upper left corner of the fastener symbols in the figure. A number in the lower right corner gives the grip length of the fastener. If the grip length shown is not available at Boeing, fasteners supplied in kits may be one grip length longer than indicated. Also, if any of the fastener part numbers are not available or have been superseded, substitute fasteners may be supplied in Boeing kits, Boeing Document D-590 and Boeing drawing 65-88700 are used to determine the part numbers used as substitutes. MORE DATAHOLE DIAIDENTIFICATIONNAMECODE (a) (e) (f)0.190 - 0.194NAS6703-(*)BoltA BACW10BP3CDWasher BACW10BP3DPWasher BACN10JC3CDNut NAS8703-10 is optional to BACB30ZE3-10 (a) (f) 0.190 - 0.194NAS8703-(*)BoltB BACW10BP3DPWasher BACN10JC3CDNut (a) (e) (f)0.219 - 0.223BACB30NM3K4YBoltC BACW10BP32CDWasher BACW10BP32DPWasher NAS1805LNut (a) (f)0.219 - 0.223NAS8703-7YBoltD BACW10BP32DPWasher BACN10JC3CDNut (a) (c) (e) (f)0.190 - 0.194BACB30LK3-10BoltE BACW10BP3CDWasher BACW10BP3DWasher BACN10JC3CDNut (a) (b) (d)0.190 - 0.194NAS6703-10BoltF BACW10BP3CDWasher (a) (d)0.190 - 0.194BACB30LK3-6BoltG BACW10BP3CDWasher (a) (d)0.190 - 0.194BACB30LH3-(*)BoltH FIGURE 4: STOP FITTING AND INNER SKIN - INSTALLATION (SHEET 5 OF 7) BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 10, 2003 737-53A1240Revision 1 June 29, 2010 60 of 155 BOEING SERVICE BULLETIN 737-53A1240 ALERTALERT The text continues at https://openairdocs.org/service-documents/boeing/737-53a1240/file/d27d40919a78.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.