# 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 A1240-02 - Pages: 81 - PDF: https://openairdocs.org/files/sha256/39/9d/399debc0da16a9caaa0761b33fc8fa523411d0deac24a89f957fbe69c2957201 - Page: https://openairdocs.org/service-documents/boeing/737-53a1240/file/399debc0da16 ## 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: 737-53A1204 Original Issue: June 19, 2003 Revision 2: June 24, 2010 ATA System: 5311 SUBJECT: FUSELAGE - Main Frame - Frames and Bulkheads - Body Station BS 360 - BS 348.2 and BS 303.9 - BS 294.5 Stringers S-7L - S-16L Left Intercostal Inspection / Repair / Modification 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all export laws. 9E991ECCN: BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET Copyright © 2003 The Boeing Company Unpublished Work - All Rights Reserved Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable subject matter.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: June 19, 2003 737-53A1204Revision 2: June 24, 2010 1 of 81 4.0 ### Page 2 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 2 of 81 BOEING SERVICE BULLETIN 737-53A1204 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 6 B. Concurrent Requirements ...................................... 2 6 C. Reason ................................................ 2 7 D. Description .............................................. 2 7 E. Compliance .............................................. 2 9 F. Approval ............................................... 3 6 G. Manpower .............................................. 3 6 H. Weight and Balance Changes .................................... 3 8 I. Electrical Load Data ......................................... 3 8 J. References .............................................. 3 8 1. Existing Data: ......................................... 3 8 2. Data supplied with this Service Bulletin: ........................... 3 9 3. Installation Drawings Used in the Preparation of this Service Bulletin: ........... 3 9 K. Publications Affected ........................................ 3 9 L. Interchangeability and Intermixability of Parts ........................... 3 9 2. MATERIAL INFORMATION ........................................ 4 1 A. Material - Price and Availability ................................... 4 1 B. Industry Support Information .................................... 4 1 C. Parts Necessary For Each Airplane ................................. 4 1 1. Kits/Parts: ........................................... 4 1 2. Parts and Materials Supplied by the Operator: ........................ 4 1 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: INTERCOSTAL WEB, ATTACHMENT CLIPS, STRAP AND STRINGER SPLICE CHANNEL - PASSENGER AIRPLANES THAT ARE PREVIOUSLY NOT REPAIRED PER SRM - INSPECTION [Group 1, 3] ........................................... 5 0 FIGURE 2: INTERCOSTAL WEB, ATTACHMENT CLIPS, STRAP, STRINGER SPLICE AND STRINGER REINFORCEMENT AUX INTERCOSTAL - PASSENGER AIRPLANES - INSPECTION [Group 1 , 3 ] ............................................... 5 3 FIGURE 3: INTERCOSTAL WEB, ATTACHMENT CLIP, STRAP AND STRINGER - CARGO AIRPLANES - INSPECTION [Group 2] ................................... 5 9 FIGURE 4: REPAIRED INTERCOSTAL WEB, ATTACHMENT CLIPS, STRINGER SPLICE CHANNEL, REPAIRED TEE, AND STRAP - PASSENGER AIRPLANES - INSPECTION [Group 1, 3] . 66 FIGURE 5: INTERCOSTAL WEB, ATTACHMENT CLIP AND STRAP - PASSENGER AIRPLANES AND NOT PREVIOUSLY REPAIRED PER SRM - INSPECTION [Group 4] ........... 6 9 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 3 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 4 FIGURE 6: REPAIRED INTERCOSTAL WEB, ATTACHMENT CLIPS, TEE AND STRAP - PASSENGER AIRPLANES - INSPECTION [Group 4] ............................ 7 2 FIGURE 7: INTERCOSTAL WEB, ATTACHMENT CLIPS, STRAP, AND STRINGER REINFORCEMENT AUX INTERCOSTAL - PASSENGER AIRPLANES - INSPECTION [Group 4] ....... 7 5 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 4 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 5 Commercial Airplanes 737 Service Bulletin ALERT Revision Transmittal SheetNumber: 737-53A1204Original Issue: June 19, 2003 Revision 2: June 24, 2010 ATA System: 5311 SUBJECT: FUSELAGE - Main Frame - Frames and Bulkheads - Body Station BS 360 - BS 348.2 and BS 303.9 - BS 294.5 Stringers S-7L - S-16L Left Intercostal Inspection / Repair / Modification This revision includes all pages of the service bulletin. COMPLIANCE INFORMATION RELATED TO THIS REVISION More work is necessary on airplanes changed in accordance with Revision 1 of this service bulletin. The more work is necessary on airplanes changed in accordance with Revision 1 of this service bulletin to include inspection of cargo barrier net fitting at S-15L lower door stop intercostal between BS 348.2 and BS 360. REASON FOR REVISION This revision is sent to update the compliance info and inspection instructions on the intercostals as well as parts replacement and repair instructions if cracks are found at S-14L, S-15L and S-16L intercostals. In addition, an additional inspection of the S-15L aft intercostal from BS 348.2 to BS 360 for -200C airplanes was added. These sections were changed: 1. In Paragraph 1.A.1., Airplanes, Group 1 airplanes listed in Revision 1 is split into Group 1, Group 3 and Group 4. 2. In Paragraph 1.D., Description, revised as follows: a. Added Group 3 and Group 4 passenger airplanes. b. Added more work statement. c. Added Maintenance Zone Tables. 3. In Paragraph 1.E., Compliance, revised as follows: BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 5 of 81 ### Page 6 a. Formatting changes. b. Added inspection of S-15L from BS 348.2 to BS 360 for Group 2 airplanes. c. Added compliance information for repairs of S-14L, S-15L and S-16L intercostals from BS 348.2 to BS 360 in Group 1 and 3 airplanes. d. Additional tables were added for Group 4 airplanes. 4. In Paragraph 1.G., Manpower, changed table as follows: a. Removed repair of S-16L intercostal. b. Added for changes made per Figures 3. 5. In Paragraph 1.J., References, added Federal Aviation Administration (FAA) Airworthiness Directive 2009-16-14. 6. In Paragraph 1.K., Publications, added as follows: a. Changed in accordance with information notice IN01. b. Added damage tolerance information. 7. In Paragraph 2.B., Industry Support Information, changed statement. 8. In Paragraph 3.B., Work Instructions, revised as follows: a. Revised to redirect work to SB 737-53A1240 R1 if cracks are found in S-16L door stop intercostal between BS 351.2 through BS 360 for Group 1 and Group 3 airplanes. b. Revised to redirect work to SB 737-53A1240 R1 if cracks are found in S-14L, S-15L door stop intercostal aft of BS 348.2 frame and S-16L door stop intercostal from BS 348.2 to BS 351.2 for Group 1 and Group 3 airplanes. c. Added note that Structural Repair Manual (SRM) repairs of cracks found in S-16L intercostal are obsolete and can no longer be used for new repairs. d. Added inspection requirement for S-15L intercostal for cargo airplanes. e. Group 1 of revision 1 was divided into Group 1, Group 3 and Group 4. 9. Figure 2, added S-15L inspection requirement. 10. Figure 3, added for Cargo Inspections, was Figure 2. 11. Figures 4 through 7, added for clarification. 12. The data given in Information Notice (IN) 737-53A1204 R01 IN02 is included in this revision. Vertical lines are put on the left edge of each page, except in Paragraph 1.A., Effectivity, to show the location of important changes. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 6 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 7 Pages with no vertical lines have no important changes. REVISION HISTORY June 19, 2003Original Issue: March 26, 2007Revision 1: June 24, 2010Revision 2: BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 7 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 8 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 8 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT BLANK PAGE ### Page 9 Commercial Airplanes 737 Service Bulletin ALERT SummaryNumber: 737-53A1204Original Issue: June 19, 2003 Revision 2: June 24, 2010 ATA System: 5311 SUBJECT: FUSELAGE - Main Frame - Frames and Bulkheads - Body Station BS 360 - BS 348.2 and BS 303.9 - BS 294.5 Stringers S-7L - S-16L Left Intercostal Inspection / Repair / Modification 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 Several operators have reported airplanes with fatigue cracks in the intercostals on the forward and aft side of the forward entry door. The cracks are caused by fatigue from pressure loads applied at door stop fittings. Incorporation of this service bulletin will prevent a possible decompression and unscheduled down time. Prior to the original release of this service bulletin, eleven operators had reported airplanes with fatigue cracks in the intercostal web at body station (BS) 358.5 and stringer S-16L. The cracks extend from the inboard edge of the intercostal through tooling or fastener holes and terminate at the 2.0 inch diameter lightening hole. Three operators had reported four airplanes with cracks in intercostals at S-11L, S-12L and S-13L on the forward and aft side of the forward entry door. All additional cracks were in the radius of return flanges of the webs and attachment clips. One operator had reported one airplane with cracks in the stringer splice channels at S-14L and S-15L on the aft side of the forward entry door. The cracks were in the intercostal web attachment flange at the aft end of the intercostal. Since the original release of this service bulletin, many operators have reported over one hundred cracks. Cracks have been found at all doorstop and hinge support intercostals on both the forward and aft side of the forward entry door. Operators have also reported cracks on several airplanes at multiple intercostal locations. The Federal Aviation Administration (FAA) has issued Airworthiness Directive (AD) 2009-16-14 which requires incorporation of this service bulletin. Boeing Structural Item Interim Advisory (SIIA) 737-183 is related to this service bulletin. Boeing Service Related Problem (SRP) 737-SRP-53-0266 is related to this service bulletin. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 9 of 81 ### Page 10 ACTION (PRR 35005-288R) The airplane effectivity is divided in four groups. Group 1, Group 3 and Group 4 are for passenger airplanes and Group 2 is for cargo airplanes. Group 1, Group 3 and Group 4 airplanes are divided to differentiate the stringer connection at station 360 and intercostal configurations at hinge supports for the forward entry door. Group 1 and Group 3 airplanes have similar stringer splice configuration at station 360 fuselage production section joint. Group 4 airplanes have the stringer tie fitting configuration at station 360 production section joint. Group 1 and group 4 have the same similar intercostal at door hinge supports and Group 3 airplanes have the later intercostal configuration at door hinge supports. Group 2 are cargo airplanes and also have different intercostals at door hinge supports. For Groups 1-4 airplanes gain access to stringer S-7L - S-16L intercostals forward of the forward entry door cutout (between BS 294.5 and BS 303.9) and aft of the forward entry door cutout (between BS 348.2 and BS 360). Inspect the intercostal webs, attachment clips, straps, stringer reinforcement angle and stringer splice channels for cracks. Refer to Accomplishment Instructions Part 1 and Part 2 for Group 1 and Group 3 passenger airplanes, refer to Accomplishment Instructions Part 3 for Group 2 cargo airplanes, and refer to Accomplishment Instructions Part 4 and Part 5 for Group 4 passenger airplanes. For Group 1 and Group 3 passenger airplanes, if cracks are found at S-14L, S-15L and S-16L intercostal between BS 348.2 and BS 360, do the repair in accordance with accomplishment instruction 3.B. of this service bulletin. For group 1 and group 3 airplanes, if crack or damage is found at any other intercostal or the crack location is not covered by the repairs in accordance with SB 737-53A1240, Revision 1 contact Boeing for repair instructions and do the repair. For Group 2 cargo airplanes, if cracks are found, contact Boeing for repair instruction and do the repair. For Group 4 passenger airplanes, if cracks are found, contact Boeing for repair instructions. EFFECTIVITY 737-100/200/200C/300/400/500 Airplanes. Refer to Paragraph 1.A.1., Airplanes for the list of affected airplanes. COMPLIANCE See Section 1.E. Compliance for Boeing recommended compliance times and inspection intervals. Federal Aviation Administration (FAA) Airworthiness Directive 2009-16-14, is related to this service bulletin. INDUSTRY SUPPORT INFORMATION Boeing warranty remedies are not available for the inspections given in this service bulletin. MANPOWER See table in Section 1.G. Manpower for man-hour estimate. MATERIAL INFORMATION None. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 10 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 11 (OCR) BOEING SERVICE BULLETIN 737-53A1204 ALERT ALERT FORWARD ENTRY DOOR S-7L S-16L > S-7L DOOR FRAME BS AREA 351.20 BS 360 INTERCOSTAL BS WEB 351.20 BS 303.9 S-16L 294.5 BS 277 BS BS TYPICAL CRACK 259.5 LAND BS 360 SKIN • STRAP STRINGER S-16L CLIP FRAME TYPICAL CRACKS- ADDTIONAL CRACKS ARE IN BEND RADIUS OF RETURN FLANGES OF THE WEBS AND TOOLING ATTACHMENT CLIPS HOLE TYPICAL CRACK INSPECT INTERCOSTALS AT S-7L THRU S-16L AROUND THE FORWARD ENTRY DOOR AND AT BS 348.2 TO BS 360 AT BS 294.5 TO BS 303.9 V83943 Original Issue: June 19, 2003 Revision 2: June 24, 2010 737-53A1204 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 11 of 81 ### Page 12 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 12 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT BLANK PAGE ### Page 13 Commercial Airplanes 737 Service Bulletin ALERT Number: 737-53A1204 Original Issue: June 19, 2003 Revision 2: June 24, 2010 ATA System: 5311 SUBJECT: FUSELAGE - Main Frame - Frames and Bulkheads - Body Station BS 360 - BS 348.2 and BS 303.9 - BS 294.5 Stringers S-7L - S-16L Left Intercostal Inspection / Repair / Modification 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 D6-19567, Part 3 for Airplane Variable Number, Line Number, and Serial Number data. This service bulletin is for the airplanes shown below. DESCRIPTIONCONFIGURATIONGROUP 737-100/200/300/400/500 series airplanes.-1 737-200C cargo airplanes.-2 737-300/400/500 series airplanes.-3 737-100/200 series airplanes.-4 Airplane Models: 737-100, 737-200, 737-200C, 737-300, 737-400, 737-500 GroupVariable Number 4PA001 - PA013 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 13 of 81 ### Page 14 GroupVariable Number 1PA014 - PA022 4PA099 1PA231 - PA232 1PC001 - PC005 4PG001 - PG014 1PG015 - PG075 4PG199 1PG201 - PG230 1PG251 - PG255 4PG271 - PG272 1PG273 - PG279 4PG301 1PG302 - PG314 1PG331 - PG332 1PG351 - PG356 1PG375 1PG401 - PG403 1PG431 - PG442 1PG471 - PG475 1PG501 - PG505 1PG571 - PG586 1PG621 - PG630 1PG651 - PG652 1PG701 - PG705 1PH001 1PH011 - PH013 1PH021 - PH024 1PH701 - PH715 1PH731 - PH732 1PH741 - PH743 1PJ001 - PJ009 1PJ031 - PJ032 1PJ071 - PJ072 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 14 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 15 GroupVariable Number 1PJ101 - PJ119 1PJ201 - PJ219 1PJ301 - PJ302 3PJ551 - PJ561 3PJ601 - PJ615 3PJ811 3PJ816 - PJ817 1PK026 - PK029 1PK041 - PK053 1PK061 - PK070 1PK081 - PK082 1PK091 - PK099 1PK101 - PK103 1PK111 - PK120 1PK141 - PK146 1PK201 - PK204 1PK211 - PK223 1PK231 - PK241 1PK251 - PK258 1PK271 - PK274 1PK281 - PK289 1PK291 1PK301 - PK318 1PK341 1PK351 - PK361 1PK391 1PK431 - PK433 1PK451 - PK452 1PK461 - PK469 1PK495 1PK501 - PK504 1PK511 - PK515 1PK519 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 15 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 16 GroupVariable Number 1PK521 - PK528 1PK541 - PK565 1PK581 1PK591 - PK599 1PK601 - PK617 1PK621 - PK637 1PK641 - PK642 1PK661 - PK666 1PK671 - PK681 1PK691 - PK697 1PK711 - PK716 1PK731 - PK765 1PK771 - PK779 1PK801 - PK804 1PK819 - PK827 1PK830 1PK861 - PK863 1PK871 - PK874 1PK881 - PK884 1PK901 - PK938 1PK971 - PK974 1PL001 - PL028 1PL061 1PL081 1PL101 - PL113 1PL151 1PL171 - PL172 1PL201 - PL203 1PL221 1PL401 - PL417 1PL421 1PL441 1PL451 - PL456 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 16 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 17 GroupVariable Number 1PL471 1PL491 1PL501 - PL506 1PL551 - PL562 1PL581 1PL601 - PL603 1PL611 1PL621 - PL626 1PL631 - PL632 1PL711 - PL712 1PL716 - PL747 1PL756 1PL758 1PL761 - PL770 1PL781 - PL788 1PL793 1PL801 - PL803 1PM001 - PM006 1PM016 - PM017 1PM021 - PM023 1PM051 - PM066 1PM101 - PM119 1PM141 - PM142 1PM171 1PM181 1PM251 - PM255 1PM281 - PM283 1PM381 - PM399 1PM401 - PM414 3PM415 - PM417 1PM541 3PM542 - PM550 1PM551 - PM560 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 17 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 18 GroupVariable Number 3PM561 - PM564 1PN001 - PN002 1PN021 - PN043 1PN081 - PN086 1PN101 - PN117 1PN131 - PN163 1PN401 - PN420 1PN431 - PN433 1PN451 - PN456 1PN471 - PN474 1PN481 1PN491 - PN493 1PN501 - PN502 1PN511 - PN512 1PN521 1PP001 - PP054 1PP101 - PP169 1PP181 - PP199 1PP201 - PP205 1PP221 1PP231 - PP243 1PP281 - PP286 1PP301 - PP305 1PP351 - PP353 1PP376 - PP384 1PP391 - PP393 1PP401 - PP440 1PP471 - PP475 1PP501 - PP517 3PP518 - PP520 1PP521 - PP522 1PP631 - PP634 1PP651 - PP652 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 18 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 19 GroupVariable Number 1PP671 - PP699 1PP701 - PP733 1PP771 - PP779 1PP801 - PP808 1PP821 - PP827 1PP831 - PP848 1PP851 - PP852 1PP861 - PP874 3PP875 - PP877 1PP891 - PP899 1PP901 - PP936 1PP946 - PP948 1PP951 - PP952 1PP961 - PP967 1PP981 - PP991 1PP993 1PQ001 - PQ016 1PQ026 - PQ041 1PQ051 - PQ092 1PQ101 - PQ199 1PQ201 - PQ202 1PQ221 - PQ237 1PQ241 - PQ243 1PQ251 - PQ267 1PQ281 - PQ295 3PQ296 - PQ299 1PQ301 - PQ307 1PQ331 - PQ332 1PQ341 - PQ344 3PQ345 - PQ348 1PQ361 - PQ367 3PQ368 - PQ373 3PQ391 - PQ395 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 19 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 20 GroupVariable Number 1PQ401 - PQ405 3PQ406 - PQ410 1PQ411 - PQ413 3PQ414 - PQ418 1PQ421 3PQ431 - PQ438 3PQ447 - PQ448 3PQ451 3PQ454 3PQ471 - PQ475 3PQ479 - PQ480 1PQ481 1PQ486 3PQ487 1PQ491 - PQ492 3PQ493 1PQ771 3PQ772 3PQ791 - PQ793 3PQ801 - PQ805 3PQ931 - PQ935 3PQ951 3PQ971 - PQ997 3PR001 - PR017 3PR021 - PR034 3PR041 - PR045 3PR061 - PR072 3PR077 - PR082 3PR091 - PR092 3PR096 3PR101 3PR121 - PR122 3PR131 - PR132 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 20 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 21 GroupVariable Number 3PR141 - PR143 3PR161 - PR172 3PR181 1PS601 - PS616 3PS617 - PS630 1PS631 1PS636 - PS638 1PS641 - PS644 1PS651 - PS657 1PS666 - PS669 1PS691 - PS692 1PS701 - PS703 3PS704 - PS706 1PS751 - PS752 3PS753 - PS799 3PS811 3PS836 - PS837 3PS841 - PS846 3PS851 - PS852 3PS856 3PS861 - PS863 3PS866 - PS868 3PS871 - PS874 3PS896 - PS897 3PS901 - PS941 3PS956 - PS957 3PS961 - PS963 3PS971 - PS978 1PT001 - PT011 3PT012 - PT015 1PT021 - PT026 3PT027 - PT031 1PT041 - PT059 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 21 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 22 GroupVariable Number 3PT060 - PT064 1PT101 - PT105 1PT121 - PT125 3PT126 - PT138 1PT146 - PT148 1PT161 - PT169 3PT170 1PT181 - PT187 3PT188 1PT211 - PT220 1PT295 1PT301 - PT302 3PT303 - PT309 1PT331 - PT360 1PT381 - PT399 1PT401 - PT431 3PT432 - PT438 1PT501 - PT510 3PT511 - PT517 1PT561 - PT565 1PT581 - PT583 3PT584 - PT586 1PT611 - PT621 1PT641 3PT642 - PT644 1PT651 - PT654 3PT655 - PT656 1PT671 3PT672 3PT681 - PT685 1PT701 - PT703 3PT716 - PT717 3PT721 - PT725 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 22 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 23 GroupVariable Number 3PT801 - PT834 3PT851 - PT854 3PT871 - PT886 3PT901 - PT930 3PT971 - PT973 3PT981 - PT985 3PT996 1PU001 - PU025 3PU301 3PU311 - PU313 1PV001 - PV055 1PV201 - PV202 3PV203 - PV209 3PV226 - PV229 1PV231 - PV237 1PV271 - PV272 3PV281 - PV287 3PV296 3PV301 - PV302 3PV351 3PV356 - PV357 1PW001 - PW054 1PW061 - PW068 1PW072 3PW086 - PW088 1PW091 - PW094 1PW101 3PW102 3PW106 1PW111 - PW120 1PW156 - PW157 1PW161 - PW166 3PW167 - PW171 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 23 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 24 GroupVariable Number 1PW201 - PW216 3PW217 - PW230 1PW231 - PW237 3PW238 - PW252 1PW261 3PW262 - PW264 1PW265 - PW266 3PW267 - PW268 3PW271 - PW276 3PW278 1PW281 3PW282 - PW292 1PW293 1PW296 1PW301 - PW322 3PW323 - PW327 3PW401 - PW408 3PW411 - PW418 3PW421 - PW424 3PW431 - PW435 3PW441 - PW450 3PW461 - PW467 1PW501 - PW504 1PW511 - PW520 3PW521 - PW522 3PW524 - PW530 1PW531 - PW544 3PW545 - PW550 3PW556 - PW557 1PW561 - PW564 1PW571 - PW576 1PW591 - PW596 1PW611 - PW620 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 24 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 25 GroupVariable Number 3PW621 - PW622 1PW631 - PW633 3PW634 - PW637 1PW661 - PW662 1PW681 - PW683 1PW701 - PW702 1PW711 - PW716 3PW717 1PW741 - PW742 1PW761 3PW771 3PW831 3PW851 - PW856 2PX071 2PX701 2PY001 - PY008 2PY021 - PY022 2PY031 2PY036 - PY037 2PY046 - PY048 2PY051 - PY053 2PY056 - PY057 2PY101 - PY103 2PY111 - PY113 2PY131 - PY135 2PY141 - PY143 2PY151 - PY154 2PY156 - PY157 2PY161 - PY162 2PY166 2PY191 2PY201 2PY221 - PY222 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 25 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 26 GroupVariable Number 2PY231 2PY241 - PY244 2PY270 - PY275 2PY281 2PY286 2PY301 - PY304 2PY321 - PY323 2PY341 - PY346 2PY361 - PY362 2PY381 2PY401 2PY409 - PY411 2PY421 - PY422 2PY441 2PY451 2PY461 - PY463 2PY591 - PY595 2PY611 - PY612 2PY621 2PY631 2PY651 2PY671 - PY672 2PY721 2PY741 2. Spares Affected None B. Concurrent Requirements The stringer intercostal inspections in this service bulletin must be done at the same time as the frame inspection in the Service Bulletin below: DescriptionService BulletinCompany Forward Door, Inspection and Repair of Inner Frame Chord, Stringers and Intercostals. 737-53A1240, Revision 1Boeing BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 26 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 27 C. Reason Several operators have reported airplanes with fatigue cracks in the intercostals on the forward and aft side of the forward entry door. The cracks are caused by fatigue from pressure loads applied at door stop fittings. Incorporation of this service bulletin will prevent a possible decompression and unscheduled down time. Prior to the original release of this service bulletin, eleven operators had reported airplanes with fatigue cracks in the intercostal web at body station (BS) 358.5 and stringer S-16L. The cracks extend from the inboard edge of the intercostal through tooling or fastener holes and terminate at the 2.0 inch diameter lightening hole. Three operators had reported four airplanes with cracks in intercostals at S-11L, S-12L and S-13L on the forward and aft side of the forward entry door. All additional cracks were in the radius of return flanges of the webs and attachment clips. One operator had reported one airplane with cracks in the stringer splice channels at S-14L and S-15L on the aft side of the forward entry door. The cracks were in the intercostal web attachment flange at the aft end of the intercostal. Since the original release of this service bulletin, many operators have reported over one hundred cracks. Cracks have been found at all doorstop and hinge support intercostals on both the forward and aft side of the forward entry door. Operators have also reported cracks on several airplanes at multiple intercostal locations. The Federal Aviation Administration (FAA) has issued Airworthiness Directive (AD) 2009-16-14 which requires incorporation of this service bulletin. Boeing Structural Item Interim Advisory (SIIA) 737-183 is related to this service bulletin. Boeing Service Related Problem (SRP) 737-SRP-53-0266 is related to this service bulletin. Revision 1 was sent to change the repeat inspection intervals in the compliance paragraph and the following changes: — Change the Service Bulletin status from "Special Attention" to "Alert" and add reference to the related Airworthiness Directive (AD). — Planing Information - Change the repeat inspection intervals in the compliance paragraph. Update the service history information relating to cracks that have been reported since the original release of this service bulletin. Add the reference to the Service Related Problem. Update the Structural Repair Manual (SRM) references in the Publications Affected and References paragraphs. Update the Aircraft Maintenance Manual (AMM) references in the References paragraph. — Accomplishment Instructions - Update the SRM references for the stringer S-16L repair. Update the AMM references for the lavatory removal/installation. Added Part 4 to the Work Instructions to inspect intercostals aft of the forward entry door on cargo airplanes. — The data given in Information Notice 737-53-1204 IN 01 is included in this revision. The incorrect SRM figure number has been changed to the correct figure number. Revision 2 is sent to update the compliance info and inspection instructions on the intercostals as well as parts replacement and repair instructions if cracks are found at S-14L, S-15L and S-16L intercostals. In addition, inspection of the S-15L aft intercostal from BS 348.2 to BS 360 for -200C airplanes was added. D. Description The airplane effectivity is divided in four groups. Group 1, Group 3 and Group 4 are for passenger airplanes and Group 2 is for cargo airplanes. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 27 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 28 Group 1, Group 3 and Group 4 airplanes are divided to differentiate the stringer connection at station 360 and intercostal configurations at hinge supports for the forward entry door. Group 1 and Group 3 airplanes have similar stringer splice configuration at station 360 fuselage production section joint. Group 4 airplanes have the stringer tie fitting configuration at station 360 production section joint. Group 1 and group 4 have the same similar intercostal at door hinge supports and Group 3 airplanes have the later intercostal configuration at door hinge supports. Group 2 are cargo airplanes and also have different intercostals at door hinge supports. For Groups 1-4 airplanes gain access to stringer S-7L - S-16L intercostals forward of the forward entry door cutout (between BS 294.5 and BS 303.9) and aft of the forward entry door cutout (between BS 348.2 and BS 360). Inspect the intercostal webs, attachment clips, straps, stringer reinforcement angle and stringer splice channels for cracks. Refer to Accomplishment Instructions Part 1 and Part 2 for Group 1 and Group 3 passenger airplanes, refer to Accomplishment Instructions Part 3 for Group 2 cargo airplanes, and refer to Accomplishment Instructions Part 4 and Part 5 for Group 4 passenger airplanes. For Group 1 and Group 3 passenger airplanes, if cracks are found at S-14L, S-15L and S-16L intercostal between BS 348.2 and BS 360, do the repair in accordance with accomplishment instruction 3.B. of this service bulletin. For group 1 and group 3 airplanes, if crack or damage is found at any other intercostal or the crack location is not covered by the repairs in accordance with SB 737-53A1240, Revision 1 contact Boeing for repair instructions and do the repair. For Group 2 cargo airplanes, if cracks are found, contact Boeing for repair instruction and do the repair. For Group 4 passenger airplanes, if cracks are found, contact Boeing for repair instructions. An evaluation form is attached to this service bulletin. Please use this form to tell us what you think of the quality of this service bulletin. NOTE: Inspection and maintenance requirements are shown in Section 3., ACCOMPLISHMENT INSTRUCTIONS. 1. 2. If the damaged area is more than the specified limits, write to Boeing for repair instructions. Give the size and location of the damage. When possible, send sketches and photographs. If the damage includes corrosion, send data on the length, width, and largest depth of clean up. Send to: BOEING COMMERCIAL AIRPLANES GROUP ATTENTION: MANAGER, AIRLINE SUPPORT 3. This note is applicable to those passenger airplanes which have been modified to a cargo configuration by a non-Boeing Supplemental Type Certificate (STC): If the structure in the region of the Forward Entry Door applicable to this Service Bulletin remains unchanged from the passenger airplane production configuration, accomplish the instructions for Group 1 airplanes. If any of the structure around the Forward Entry Door has been changed as part of the modification from a passenger to a cargo airplane, the operator must contact the STC holder for additional information regarding accomplishment instructions for this Service Bulletin. Revision 1 - More work is necessary on cargo airplanes changed as shown in the initial release of this service bulletin. The repeat inspection intervals in the compliance paragraph have been changed. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 28 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 29 Revision 2 - More work is necessary on cargo airplanes changed in accordance with Revision 1 of this service bulletin to include inspection of cargo barrier net fitting at S-15L lower door stop intercostal between BS 348.2 and BS 360. The work in this service bulletin is done in the maintenance zone(s) given below. Group 1, 3: Affected Maintenance Zones ZoneModel 105, 107737-300, 737-400, 737-500 Group 1, 4: Affected Maintenance Zones ZoneModel 1-5, 1-7737-100, 737-200 Group 2: Affected Maintenance Zones ZoneModel 1-5, 1-7737-200, 737-200C E. Compliance Federal Aviation Administration (FAA) Airworthiness Directive 2009-16-14, is related to this service bulletin. Boeing recommends that operators perform the Inspections at the times indicated in the tables that follow. Group 1, 3: Table 1: INSPECTION OF S-16L DOOR STOP INTERCOSTAL FROM BS 348.2 TO BS 360 Repeat IntervalCompliance Time (whichever oc- curs later) ActionCondition --Within 6,000 flight cycles from the date of the previ- ous inspection At intercostal location S- 16L from BS 348.2 to BS 360, do a Detailed Inspec- tion and High Frequency Eddy Current (HFEC) In- spection for cracks in ac- cordance with Accom- plishment Instructions 3.B. Part 1. Airplanes that have accom- plished the inspection or repair of S-16L intercostal between BS 348.2 to BS 360 in accordance with the Original Release or Revi- sion 1 of this service bul- letin BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 29 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 30 Group 1, 3: Table 1: INSPECTION OF S-16L DOOR STOP INTERCOSTAL FROM BS 348.2 TO BS 360 Repeat IntervalCompliance Time (whichever oc- curs later) ActionCondition --Within 15,000 total flight cycles At intercostal location S- 16L from BS 348.2 to BS 360, do a Detailed Inspec- tion and High Frequency Eddy Current (HFEC) In- spection for cracks in ac- cordance with Accom- plishment Instructions 3.B Part 1. Airplanes that have NOT accomplished the inspec- tion or repair of S-16L inter- costal between BS 348.2 to BS 360 in accordance with the Original Release or Revision 1 of this service bulletin OR within 4,500 flight cycles from the re- lease date of Revi- sion 1 of this Ser- vice Bulletin 6,000 flight cycles--At intercostal location S- 16L from BS 348.2 to BS 360, do a Detailed Inspec- tion and High Frequency Eddy Current (HFEC) In- spection for cracks in ac- cordance with Accom- plishment Instructions 3.B Part 1. No crack(s) found (a)Before further flightDo the repair in accor- dance with Accomplish- ment Instructions 3.B Part 1 or contact Boeing. Crack(s) found 6,000 flight cyclesWithin 6,000 flight cycles from the date of the last in- spection At intercostal location S- 16L from BS 348.2 to BS 360, do a Detailed Inspec- tion and High Frequency Eddy Current (HFEC) In- spection for cracks in ac- cordance with Accom- plishment Instructions 3.B Part 1. If S-16L intercostal was re- paired in accordance with Accomplishment Instruc- tions 3.B Part 1 (a) Repair does not terminate the inspection requirements. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 30 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 31 Group 1, 3: Table 2: INSPECTION OF S-7L TO S-16L INTERCOSTALS FROM BS 294.5 TO BS 303.9 AND S-7L TO S-15L INTERCOSTALS FROM BS 348.2 TO BS 360 Repeat IntervalCompliance Time (whichever oc- curs later) ActionCondition --Within 6,000 flight cycles from the date of the previ- ous inspection At intercostal locations S- 7L to S-15L from BS 348.2 to BS 360 and S-7L to S-16L from BS 294.5 to BS 303.9, do a De- tailed Inspection and High Frequency Eddy Current (HFEC) Inspection for cracks in accordance with Accomplishment Instruc- tions 3.B Part 2. Airplanes that have accom- plished the inspections in accordance with the Origi- nal Release or Revision 1 of this service bulletin --Within 15,000 total flight cycles At intercostal locations S- 7L to S-15L from BS 348.2 to BS 360 and S-7L to S-16L from BS 294.5 to BS 303.9, do a De- tailed Inspection and High Frequency Eddy Current (HFEC) Inspection for cracks in accordance with Accomplishment Instruc- tions 3.B Part 2. Airplanes that have NOT accomplished the inspec- tions in accordance with the Original Release or Revision 1 of this service bulletin OR within 4,500 flight cycles from the re- lease date of Revi- sion 1 of this Ser- vice Bulletin 6,000 flight cycles--At intercostal locations S- 7L to S-15L from BS 348.2 to BS 360 and S-7L to S-16L from BS 294.5 to BS 303.9, do a De- tailed Inspection and High Frequency Eddy Current (HFEC) Inspection for cracks in accordance with Accomplishment Instruc- tions 3.B Part 2. No crack(s) found (a)Before further flightDo the repair in accor- dance with Accomplish- ment Instructions 3.B. Part 2 or contact Boeing. Crack(s) found in S-14L and S-15L intercostal from BS 348.2 to BS 360 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 31 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 32 Group 1, 3: Table 2: INSPECTION OF S-7L TO S-16L INTERCOSTALS FROM BS 294.5 TO BS 303.9 AND S-7L TO S-15L INTERCOSTALS FROM BS 348.2 TO BS 360 Repeat IntervalCompliance Time (whichever oc- curs later) ActionCondition 6,000 flight cyclesWithin 6,000 flight cycles from the date of the last in- spection At intercostal locations S- 14L and S-15L from BS 348.2 to BS 360 do a De- tailed Inspection and High Frequency Eddy Current (HFEC) Inspection for cracks in accordance Ac- complishment Instruc- tions 3.B Part 2. If S-14L or S-15L inter- costal are repaired in accor- dance with Accomplish- ment Instructions 3.B. Part 2 --Before further flightContact Boeing for repair instructions Crack(s) found in inter- costals or locations not covered by the above re- pair (a) Repair does not terminate the inspection requirements. Group 2: Table 3: INSPECTION OF S-7L TO S-16L INTERCOSTALS FROM BS 294.5 TO BS 303.9 AND S- 8L, S-10L, S-12L, S-14L, S-15L AND S-16L INTERCOSTALS FROM BS 348.2 TO BS 360 Repeat IntervalCompliance Time (whichever oc- curs later) ActionCondition --Within 6,000 flight cycles from the date of the previ- ous inspection At intercostal locations S- 7L to S-16L from BS 294.5 to BS 303.9, do a Detailed Inspection in ac- cordance with Accom- plishment Instructions 3.B Part 3. Airplanes that have accom- plished the inspections in accordance with Revision 1 of this service bulletin --Within 6,000 flight cycles from the date of the previ- ous inspection At intercostal locations S- 8L, S-10L, S-12L, S-14L, S-15L and S-16L from BS 348.2 to BS 360, do a Detailed Inspection in ac- cordance with Accom- plishment Instructions 3.B Part 3. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 32 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 33 Group 2: Table 3: INSPECTION OF S-7L TO S-16L INTERCOSTALS FROM BS 294.5 TO BS 303.9 AND S- 8L, S-10L, S-12L, S-14L, S-15L AND S-16L INTERCOSTALS FROM BS 348.2 TO BS 360 Repeat IntervalCompliance Time (whichever oc- curs later) ActionCondition --Within 15,000 total flight cycles At intercostal locations S- 7L to S-16L from BS 294.5 to BS 303.9, do a Detailed Inspection in ac- cordance with Accom- plishment Instructions 3.B Part 3. Airplanes that have NOT accomplished inspections in accordance with Revi- sion 1 of this service bul- letin OR within 4,500 flight cycles from the re- lease date of Revi- sion 1 of this Ser- vice Bulletin --Within 15,000 total flight cycles At intercostal locations S- 8L, S-10L, S-12L, S-14L, S-15L and S-16L from BS 348.2 to BS 360, do a Detailed Inspection in ac- cordance with Accom- plishment Instructions 3.B Part 3. OR within 4,500 flight cycles from the re- lease date of Revi- sion 1 of this Ser- vice Bulletin --Before further flightContact Boeing for repair instructions Crack(s) found in 3.B Part 3 inspection 6000 flight cycles--At intercostal locations S- 7L to S-16L from BS 294.5 to BS 303.9, do a Detailed Inspection in ac- cordance with Accom- plishment Instructions 3.B Part 3. No crack(s) found 6000 flight cycles--At intercostal locations S- 8L, S-10L, S-12L, S-14L, S-15L and S-16L from BS 348.2 to BS 360, do a Detailed Inspection in ac- cordance with Accom- plishment Instructions 3.B Part 3. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 33 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 34 Group 4: Table 4: INSPECTION OF S-16L DOOR STOP INTERCOSTAL FROM BS 348.2 TO BS 360 Repeat IntervalCompliance Time (whichever occurs later) ActionCondition --Within 6,000 flight cycles from the date of the previ- ous inspection At intercostal location S- 16L from BS 348.2 to BS 360, do a Detailed Inspec- tion and High Frequency Eddy Current (HFEC) In- spection for cracks in ac- cordance with Accomplish- ment Instructions 3.B Part 4. Airplanes that have accom- plished the inspections or repair of S-16L intercostal between BS 348.2 to BS 360 in accordance with the Original Release or Revi- sion 1 of this service bul- letin --Within 15,000 total flight cycles At intercostal location S- 16L from BS 348.2 to BS 360, do a Detailed Inspec- tion and High Frequency Eddy Current (HFEC) In- spection for cracks in ac- cordance with Accomplish- ment Instructions 3.B Part 4. Airplanes that have NOT accomplished inspections or repair of S-16L inter- costal between BS 348.2 to BS 360 in accordance with the Original Release or Revision 1 of this ser- vice bulletin OR within 4,500 flight cycles from the release date of Revision 1 of this Service Bulletin --Before further flightContact Boeing for repair instructions. Crack(s) found 6,000 flight cycles--At intercostal location S- 16L from BS 348.2 to BS 360, do a Detailed Inspec- tion and High Frequency Eddy Current (HFEC) In- spection for cracks in ac- cordance with Accomplish- ment Instructions 3.B Part 4. No crack(s) found BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 34 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 35 Group 4: Table 5: INSPECTION OF S-7L TO S-16L INTERCOSTALS FROM BS 294.5 TO BS 303.9 AND S-7L TO S-15L INTERCOSTALS FROM BS 348.2 TO BS 360 Repeat IntervalCompliance Time (whichever oc- curs later) ActionCondition --Within 6,000 flight cycles from the date of the previ- ous inspection At intercostal locations S- 7L to S-15L from BS 348.2 to BS 360 and S-7L to S-16L from BS 294.5 to BS 303.9, do a De- tailed Inspection and High Frequency Eddy Current (HFEC) Inspection for cracks in accordance with Accomplishment Instruc- tions 3.B Part 5. Airplanes that have accom- plished the inspections in accordance with the Origi- nal Release or Revision 1 of this service bulletin --Within 15,000 total flight cycles At intercostal locations S- 7L to S-15L from BS 348.2 to BS 360 and S-7L to S-16L from BS 294.5 to BS 303.9, do a De- tailed Inspection and High Frequency Eddy Current (HFEC) Inspection for cracks in accordance with Accomplishment Instruc- tions 3.B Part 5. Airplanes that have NOT accomplished the inspec- tions in accordance with the Original Release or Revision 1 of this service bulletin OR within 4,500 flight cycles from the re- lease date of Revi- sion 1 of this Ser- vice Bulletin --Before further flightContact Boeing for repair instructions. Crack(s) found 6,000 flight cycles--At intercostal locations S- 7L to S-15L from BS 348.2 to BS 360 and S-7L to S-16L from BS 294.5 to BS 303.9, do a De- tailed Inspection and High Frequency Eddy Current (HFEC) Inspection for cracks in accordance with Accomplishment Instruc- tions 3.B Part 5. No crack(s) found BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 35 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 36 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 5, Section 1.E., "Compliance," of Service Bulletin 737-53A1204, Revision 2, as alternative method of compliance to the repair procedures and the inspection methods with corresponding compliance times specified in paragraphs (h), (i), (j), and (k) of AD 2009-16-14 . The compliance times specified in paragraphs (f) and (g) of AD 2009-16-14 remain unchanged. When this service bulletin specifies contacting Boeing for repair instructions, the repair instructions must be approved by the FAA in accordance with paragraph (m) of the AD. All provisions of AD 2009-16-14 that are not specifically referenced in the preceding paragraph remain fully applicable and must be complied with. G. Manpower The table below shows an estimate of the man-hours necessary to do this inspection / repair for each aircraft 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, 3: Part 1 - Inspection Elapsed Time (Hours) Man-HoursNumber of Persons Task 9.2518.52Access 2.02.01Figure 1 10302Close Access 21.2550.5TOTAL FOR EACH AIRPLANE BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 36 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 37 Group 1, 3: Part 2 - Inspection and Repair Elapsed Time (Hours) Man-HoursNumber of Persons Task 9.2518.52Access 2.02.01Figure 1 2.02.01Figure 2 2.02.01Figure 4 or Figure 6 2.02.01Figure 5 or Figure 7 10302Close Access 27.2556.5TOTAL FOR EACH AIRPLANE Group 2: Part 3 - Inspection Elapsed Time (Hours) Man-HoursNumber of Persons Task 9.2518.52Access 2.02.01Figure 3 10302Close Access 21.2550.5TOTAL FOR EACH AIRPLANE Group 4: Part 4 - Inspection Elapsed Time (Hours) Man-HoursNumber of Persons Task 9.2518.52Access 2.02.01Figure 1 10302Close Access 21.2550.5TOTAL FOR EACH AIRPLANE Group 4: Part 5 - Inspection Elapsed Time (Hours) Man-HoursNumber of Persons Task 9.2518.52Access 2.02.01Figure 1 2.02.01Figure 2 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 37 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 38 Group 4: Part 5 - Inspection Elapsed Time (Hours) Man-HoursNumber of Persons Task 10302Close Access 23.2552.5TOTAL FOR EACH AIRPLANE H. Weight and Balance Changes Change in Moment (Pound-Inches) Change in Weight (Pounds)Airplane NegligibleNegligible737 Airplanes I. Electrical Load Data Not applicable J. References 1. Existing Data: a. Service Related Problem (SRP) 737-SRP-53-0266. b. Federal Aviation Administration (FAA) Airworthiness Directive 2009-16-14. c. Boeing Service Bulletin 737-53A1240 R1. d. Engineering Change Memo PRR 35005-288R. e. Standard Overhaul Practices Manual (SOPM) 20-43-03. f. 737 Non-Destructive Testing (NDT) Manual Part 6, 51-00-00, Figure 4 and 23. g. 737-100/200 Aircraft Maintenance Manual (AMM) 25-21-41, 25-24-111, 25-24-112, 25-31-01 and 25-40-0. h. 737-300/400/500 Aircraft Maintenance Manual (AMM) 25-21-31, 25-24-15, 25-31-53 and 25-40-01. i. 737-100/200 Structural Repair Manual (SRM) 737-100/200 SRM 51-20-04. j. 737-300 Structural Repair Manual (SRM) 737-300 SRM 51-20-04. k. 737-400 Structural Repair Manual (SRM) 737-400 SRM 51-20-04. l. 737-500 Structural Repair Manual (SRM) 737-500 SRM 51-20-04. m. Boeing Standard Overhaul Practices Manual (SOPM) Subjects: SOPM 20-30-03, SOPM 20-41-01, SOPM 20-41-05, SOPM 20-43-03, SOPM 20-50-14 and SOPM 20-50-19. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 38 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 39 n. Boeing Standard Wiring Practices Manual (SWPM) Subjects: SWPM 20-00-13, SWPM 20-10-11 and SWPM 20-10-12. o. 737 Structural Item Interim Advisory (SIIA) 737-183. p. 737 Maintenance Planning Document. q. 737 Wiring Diagram. r. 737-SL-53-087 Service Letter (SL). 2. Data supplied with this Service Bulletin: None. None. 3. Installation Drawings Used in the Preparation of this Service Bulletin: TitleDrawing Number Frame Installation - Station 348.2065-17685 Frame Installation - Station 303.965-17684 Frame and Intercostal Installation - Station 36065-54960 Production Illustration Attach Point Locations Section 41 65-7374110PI 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: Chapter-SectionPublication 53-10-10 Figure 1737-100/200 Structural Repair Manual 53-10-04 Figure 201737-300/400/500 Structural Repair Manual 2. Damage Tolerance Based Structural Inspections: Boeing has evaluated 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. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 39 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 40 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 40 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT BLANK PAGE ### Page 41 2. MATERIAL INFORMATION A. Material - Price and Availability None. B. Industry Support Information Boeing warranty remedies are not available for the configuration changes and inspections given in this service bulletin. C. Parts Necessary For Each Airplane 1. Kits/Parts: None. 2. Parts and Materials Supplied by the Operator: None. 3. Parts Modified and Reidentified: None. 4. Parts Removed and Not Replaced: None. D. Parts Necessary to Change Spares None E. Special Tooling - Price and Availability None F. Special Tooling Necessary to do this Service Bulletin No special tools or equipment are necessary to do the change in this service bulletin. But, maintenance and overhaul tools in the manuals given in Paragraph 1.J., References, can be necessary. Examine operator tool supply to make sure all necessary tools are available. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 41 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 42 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 42 of 81 BOEING SERVICE BULLETIN 737-53A1204 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. 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. The following visual inspection is used in this bulletin and is defined as follows: — DETAILED INSPECTION is 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 access procedures may be required. 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 given in 737 Structural Repair Manual, Chapter 53. — Torque limits to tighten nuts and bolts are given in 737 Structural Repair Manual, Chapter 53. 5. For approved fastener and process material substitutions, refer to 737 Structural Repair Manual, Chapter 51, Alternate fasteners are given in 737 Structural Repair Manual Chapter 51 and Boeing Drawing 65-88700 6. Refer to the Boeing Standard Wiring Practices Manuals SWPM 20-10-11 and SWPM 20-10-12 for the wire installation procedures. 7. If the length of fasteners specified in this service bulletin do not meet the installation standards, fasteners of the same specification, or an approved substitute, longer or shorter in length may be used. 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. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 43 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 44 B. WORK INSTRUCTIONS Group 1, 3: Part 1 Inspection of S-16L door stop intercostals from BS 348.2 to BS 360 1. Access stringer S-16L intercostal between body station (BS) 348.2 and BS 360. If galley is installed remove as required. Refer to 737-100/200 AMM 25-31-01 or 737-300/400/500 AMM 25-31-53 as an accepted procedure. If lavatory is installed remove as required. Refer to 737-100/200 AMM 25-40-0 or 737-300/400/500 AMM 25-40-01 as an accepted procedure. If wind screen is installed remove as required. Refer to 737-100/200 AMM 25-24-111, 737-100/200 AMM 25-24-112 or 737-300/400/500 AMM 25-24-15 as an accepted procedure. Remove door way lining and insulation as required. Refer to 737-100/200 AMM 25-21-41 or 737-300/400/500 AMM 25-21-31 as an accepted procedure. Remove shear web between BS 348.2 and BS 351.2 frame, from cabin floor level to S-15L as specified in accomplishment instructions of service bulletin 737-53-1240 R01 for access and inspection of BS 348.2 frame. 2. Do a Detailed Inspection of the intercostal webs, attachment clips, straps, stringers and stringer splice channels and do a High Frequency Eddy Current (HFEC) Inspection of the indicated areas on the stringer splice channel and frame to intercostal attachment clip for cracks in accordance with FIGURE 1 for intercostal web previously not repaired or FIGURE 4 for intercostal web repaired per Structural Repair Manual (SRM). 3. If cracks are found, repair in accordance with the Accomplishment Instruction 3.B. Part 4 of service bulletin (SB) 737-53A1240, R1. If the damage or damage locations are not covered by the SB 737-53A1240R1 repair, contact Boeing for repair. NOTE: Refer to SB 737-53A1240, R1 airplane group in order to find the appropriate repair. NOTE: The repair as given in SB 737-53A1240, R1 or SRM requires continued inspection in accordance with FIGURE 4 using repeat inspection interval specified in Paragraph 1.E., Compliance. NOTE: The following Structural Repair Manual (SRM) repair are now obsolete and can no longer be used for new repair. RevisionSRM Repair Rev 98, 10Mar2009737-100/200 SRM 53-10-10, Figure 1 Rev 87, 10Mar2009737-300 SRM 53-10-04, Figure 201, Repair 2 Rev 70, 10Mar2009737-400 SRM 53-10-04, Figure 201, Repair 2 Rev 65, 10Mar2009737-500 SRM 53-10-04, Figure 201, Repair 2 4. If there are no cracks found, repeat the above inspections in accordance with Paragraph 1.E., Compliance. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 44 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 45 5. Install door way lining and insulation as required. Refer to 737-100/200 AMM 25-21-41 or 737-300/400/500 AMM 25-21-31 as an accepted procedure. If galley was removed, install as required. Refer to 737-100/200 AMM 25-31-01 or 737-300/400/500 AMM 25-31-53 as an accepted procedure. If lavatory was removed, install as required. Refer to 737-100/200 AMM 25-40-0 or 737-300/400/500 AMM 25-40-01 as an accepted procedure. If wind screen was removed, install as required. Refer to 737-100/200 AMM 25-24-111, 737-100/200 AMM 25-24-112 or 737-300/400/500 AMM 25-24-15 as an accepted procedure. 6. Install shear web as specified in SB 737-53A1240 R1. 7. Put the airplane back to a serviceable condition. Group 1, 3: Part 2 Inspection of S-7L to S-16L intercostals from BS 294.5 to BS 303.9 and S-7L to S-15L intercostals from BS 348.2 to BS 360 1. Access S-7L to S-16L intercostals forward of the forward entry door (BS 294.5 to BS 303.9) and S-7L to S-15L intercostals aft of the entry door (BS 348.2 to BS 360). If galley is installed remove as required. Refer to 737-100/200 AMM 25-31-01 or 737-300/400/500 AMM 25-31-53 as an accepted procedure. If lavatory is installed remove as required. Refer to 737-100/200 AMM 25-40-0 or 737-300/400/500 AMM 25-40-01 as an accepted procedure. If wind screen is installed remove as required. Refer to 737-100/200 AMM 25-24-111, 737-100/200 AMM 25-24-112 or 737-300/400/500 AMM 25-24-15 as an accepted procedure. Remove door way lining and insulation as required. Refer to 737-100/200 AMM 25-21-41 or 737-300/400/500 AMM 25-21-31 as an accepted procedure. Remove shear web between BS 348.2 and BS 351.2 Frame, from cabin floor level to S-15L as specified in concurrent accomplishment service bulletin 737-53A1240 R01 for access and inspection of BS 348.2 frame. 2. Do a Detailed Inspection of the intercostal webs, attachment clips, straps, stringers and stringer splice channels and do a High Frequency Eddy Current (HFEC) Inspection of the indicated areas on the stringer splice channel and frame to intercostal attachment clip for cracks in accordance with FIGURE 2. 3. If cracks are found in S-14L or S-15L intercostal aft of BS 348.2, repair in accordance with Accomplishment Instructions 3.B. Part 4 of SB 737-53A1240 Revision 1. If the damage or damage locations are not covered by the SB 737-53A1240 Revision 1 repair, contact Boeing for repair. NOTE: Refer to SB 737-53A1240, Revision 1 airplane group in order to find the appropriate repair. NOTE: The repair as given in SB 737-53A1240, R1 requires continued inspection in accordance with FIGURE 2 using repeat inspection interval specified in Paragraph 1.E., Compliance. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 45 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 46 4. If there are no cracks, repeat the above inspections in accordance with Paragraph 1.E., Compliance. 5. If cracks are found at intercostals other than S-14L or S-15L at between BS 348.2 and BS360, contact Boeing for repairs. 6. Install door way lining and insulation as required. Refer to 737-100/200 AMM 25-21-41 or 737-300/400/500 AMM 25-21-31 as an accepted procedure. If galley was removed, install as required. Refer to 737-100/200 AMM 25-31-01 or 737-300/400/500 AMM 25-31-53 as an accepted procedure. If lavatory was removed, install as required. Refer to 737-100/200 AMM 25-40-0 or 737-300/400/500 AMM 25-40-01 as an accepted procedure. If wind screen was removed, install as required. Refer to 737-100/200 AMM 25-24-111, 737-100/200 AMM 25-24-112 or 737-300/400/500 AMM 25-24-15 as an accepted procedure. 7. Install shear web as specified in SB 737-53A1240 R1. 8. Put the airplane back to a serviceable condition. Group 2: Part 3 Inspection of S-7L to S-16L intercostals from BS 294.5 to BS 303.9 and S-8L, S-10L, S-12L, S-14L, S-15L and S-16L intercostals from BS 348.2 to BS 360 1. Access stringers S-7L to S-16L forward of the forward entry door (BS 303.9 - BS 294.5) and aft of the forward entry door (BS 348.2 to BS 360). If galley is installed remove as required. Refer to 737-100/200 AMM 25-31-01 as an accepted procedure. If lavatory is installed remove as required. Refer to 737-100/200 AMM 25-40-0 as an accepted procedure. If wind screen is installed remove as required. Refer to 737-100/200 AMM 25-24-111 and 737-100/200 AMM 25-24-112 as an accepted procedure. Remove door way lining and insulation as required. Refer to 737-100/200 AMM 25-21-41 as an accepted procedure. Remove inner skin between BS 348.2 and BS 360 Frames, from cabin floor level to S-14L as specified in concurrent accomplishment service bulletin 737-53-1240 R01 for access and inspection of BS 348.2 frame. 2. Do a Detailed Inspection of the intercostal webs, attachment clips, straps, stringer splice and 'H' straps common to S-7L to S-16L intercostals from BS 294.5 to BS 303.9 and S-8L, S-10L, S-12L, S-14L, S-15L and S-16L intercostals from BS BS 348.2 to BS 360 for cracks in accordance with FIGURE 3. Also HFEC inspection of the indicated area on the frame to intercostal attachment clip in accordance with FIGURE 3. 3. If cracks are found, contact Boeing for repair instructions before further flight. 4. If no cracks are found, repeat the above inspections in accordance with Paragraph 1.E., Compliance. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 46 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 47 5. Install door way lining and insulation as required. Refer to 737-100/200 AMM 25-21-41 as an accepted procedure. If galley was removed, install as required. Refer to 737-100/200 AMM 25-31-01 as an accepted procedure. If lavatory was removed, install as required. Refer to 737-100/200 AMM 25-40-0 as an accepted procedure. If wind screen was removed, install as required. Refer to 737-100/200 AMM 25-24-111 and 737-100/200 AMM 25-24-112 as an accepted procedure. 6. Install inner skin as specified in SB 737-53A1240 R1. 7. Put the airplane back to a serviceable condition. Group 4: Part 4 Inspection of S-16L intercostal from BS 348.2 to BS 360 1. Access stringer S-16L intercostal between body station (BS) 348.2 and BS 360. If galley is installed remove as required. Refer to 737-100/200 AMM 25-31-01 or 737-300/400/500 AMM 25-31-53 as an accepted procedure. If lavatory is installed remove as required. Refer to 737-100/200 AMM 25-40-0 or 737-300/400/500 AMM 25-40-01 as an accepted procedure. If wind screen is installed remove as required. Refer to 737-100/200 AMM 25-24-111, 737-100/200 AMM 25-24-112 or 737-300/400/500 AMM 25-24-15 as an accepted procedure. Remove door way lining and insulation as required. Refer to 737-100/200 AMM 25-21-41 or 737-300/400/500 AMM 25-21-31 as an accepted procedure. Remove shear web between BS 348.2 and BS 351.2 from cabin floor level to S-15L as specified in concurrent accomplishment service bulletin 737-53-1240 R01 for access and inspection of BS 348.2 frame. 2. Do a Detailed Inspection of the intercostal web, attachment clips, strap and stringer and do a High Frequency Eddy Current (HFEC) Inspection of the indicated areas of the frame to intercostal attachment clip for cracks in accordance with FIGURE 5 for intercostal web previously not repaired or FIGURE 6 for intercostal web repaired per Structural Repair Manual (SRM). 3. If cracks are found, contact Boeing for repair instructions before further flight. 4. If no cracks are found, repeat the above inspections in accordance with Paragraph 1.E., Compliance. 5. Install door way lining and insulation as required. Refer to 737-100/200 AMM 25-21-41 or 737-300/400/500 AMM 25-21-31 as an accepted procedure. If galley was removed, install as required. Refer to 737-100/200 AMM 25-31-01 or 737-300/400/500 AMM 25-31-53 as an accepted procedure. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 47 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 48 If lavatory was removed, install as required. Refer to 737-100/200 AMM 25-40-0 or 737-300/400/500 AMM 25-40-01 as an accepted procedure. If wind screen was removed, install as required. Refer to 737-100/200 AMM 25-24-111, 737-100/200 AMM 25-24-112 or 737-300/400/500 AMM 25-24-15 as an accepted procedure. 6. Install shear web as specified in SB 737-53A1240 R1. 7. Put the airplane back to a serviceable condition. Group 4: Part 5 Inspection of S-7L to S-16L intercostals from BS 294.5 to BS 303.9 and S-7L to S-15L intercostals from BS 348.2 to BS 360 1. Access stringers S-7L to S-16L intercostals forward of the forward entry door (BS 294.5 to BS 303.9) and S-7L to S-15L intercostals aft of the entry door (BS 348.2 to BS 360). If galley is installed remove as required. Refer to 737-100/200 AMM 25-31-01 or 737-300/400/500 AMM 25-31-53 as an accepted procedure. If lavatory is installed remove as required. Refer to 737-100/200 AMM 25-40-0 or 737-300/400/500 AMM 25-40-01 as an accepted procedure. If wind screen is installed remove as required. Refer to 737-100/200 AMM 25-24-111, 737-100/200 AMM 25-24-112 or 737-300/400/500 AMM 25-24-15 as an accepted procedure. Remove door way lining and insulation as required. Refer to 737-100/200 AMM 25-21-41 or 737-300/400/500 AMM 25-21-31 as an accepted procedure. Remove shear web between BS 348.2 and BS 351.2 from cabin floor level to S-15L as specified in concurrent accomplishment service bulletin 737-53-1240 R01 for access and inspection of BS 348.2 frame. 2. Do a Detailed Inspection of the intercostal webs, attachment clips, straps and stringers and do a High Frequency Eddy Current (HFEC) Inspection of the indicated areas of the frame to intercostal attachment clip for cracks in accordance with FIGURE 7. 3. If cracks are found, contact Boeing for repair instructions before further flight. 4. If no cracks are found, repeat the above inspections in accordance with Paragraph 1.E., Compliance. 5. Install door way lining and insulation as required. Refer to 737-100/200 AMM 25-21-41 or 737-300/400/500 AMM 25-21-31 as an accepted procedure. If galley was removed, install as required. Refer to 737-100/200 AMM 25-31-01 or 737-300/400/500 AMM 25-31-53 as an accepted procedure. If lavatory was removed, install as required. Refer to 737-100/200 AMM 25-40-0 or 737-300/400/500 AMM 25-40-01 as an accepted procedure. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 48 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 49 If wind screen was removed, install as required. Refer to 737-100/200 AMM 25-24-111, 737-100/200 AMM 25-24-112 or 737-300/400/500 AMM 25-24-15 as an accepted procedure. 6. Install shear web as specified in SB 737-53A1240 R1. 7. Put the airplane back to a serviceable condition. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2: June 24, 2010 49 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 50 (OCR) BOEING SERVICE BULLETIN 737-53A1204 ALERT ALERT This Figure applies only to: Group 1, 3. FORWARD ENTRY DOOR S-4L S-5L S-6L 5-71 \ 8500 S-8L S-9L S-10L S-7L • S-11L S-8L S-12L S-9L S-13L ~ S-10L S-144 S-11L S-12L S-15L- S-13L S-16L~ S-14L S-15L BS S-16L 360 BS 351.20 BS 348.2 BS 303.9 BS 294.5 277 BS 259.5 BS V83955 FIGURE 1: INTERCOSTAL WEB, ATTACHMENT CLIPS, STRAP AND STRINGER SPLICE CHANNEL - PASSENGER AIRPLANES THAT ARE PREVIOUSLY NOT REPAIRED PER SRM - INSPECTION (SHEET 1 OF 3) Original Issue: June 19, 2003 Revision 2 June 24, 2010 BOEING PROPRIETARY - 737-53A1204 Copyright © Unpublished Work - See page 1 for details. 50 of 81 ### Page 51 (OCR) BOEING SERVICE BULLETIN 737-53A1204 ALERT ALERT TOOLING INTERCOSTAL WEB HOLE +1.50 1.50 TYPICAL CRACKS S-16L - TYPICAL CRACKS DOOF STOP TYPICAL TYPICAL CRACKS CRACK CLIP STA FRAME 360 STRAP 351.20 STA 348.20 STA TYPICAL CRACKS A-A INTERCOSTAL WEB REPAIR V84011 FIGURE 1: INTERCOSTAL WEB, ATTACHMENT CLIPS, STRAP AND STRINGER SPLICE CHANNEL - PASSENGER AIRPLANES THAT ARE PREVIOUSLY NOT REPAIRED PER SRM - INSPECTION (SHEET 2 OF 3) Original Issue: June 19, 2003 Revision 2 June 24, 2010 737-53A1204 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 51 of 81 ### Page 52 The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the numbers of parts necessary for each airplane. MORE DATAQTYIDENTIFICA- TION NAMETASKSTEP Do a Detailed Inspection of the door stop inter- costals, attachment clips, straps, stringers and stringer splice channel for cracks. (a) (b) (d) (e) 165-17685-( )IntercostalInspect1 165-61777-( )Stringer Splice Channel HFEC inspect both flanges of the stringer splice channel for cracks, in the indicated area with 1.5 inches distance centered about the fastener at- taching stringer clip to splice channel. (c) (e) 165-61777-( )Stringer Splice Channel Inspect2 Do a HFEC Inspection of the flange that is com- mon to the BS 348.2 frame and bend radius. (c) 165-17685-( )Frame to Inter- costal Attach- ment Clip Inspect3 (a) For intercostal web, look around flanged cutout holes, tool holes, bend radius of flanges, and at edge of each corner. For each attachment clip, look at the radius area and around each attaching fastener. For strap look at the edge of parts and around each attaching fastener. For stringer splice look at the radius area and attaching fastener locations. For stringer look over all areas of stringer common to in- tercostal. (b) This intercostal is at S-16L on the aft side of forward entry door cutout, between BS 348.2 and BS 360. (c) Use 737 NDT Part 6, 51-00-00, Figure 4 or Figure 23. (d) The stringer splice channel is located at S-16L, BS 348.2 to BS 360. (e) If cracks are found refer to SB 737-53A1240 R1 for repair instructions. FIGURE 1: INTERCOSTAL WEB, ATTACHMENT CLIPS, STRAP AND STRINGER SPLICE CHANNEL - PASSENGER AIRPLANES THAT ARE PREVIOUSLY NOT REPAIRED PER SRM - INSPECTION (SHEET 3 OF 3) BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2 June 24, 2010 52 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 53 (OCR) BOEING SERVICE BULLETIN 737-53A1204 ALERT ALERT This Figure applies only to: Group 1, 3. FORWARD ENTRY DOOR S-A1 S-5L - S-61 S-71 S-8L H S-9L S-10L S-7L S-11L S-8L S-12L S-13L S-14L S-11L Y S-12L UPPER HINGE S-15L S-13L S-16L S-14L LOWER HINGE S-15L BS S-16L 360 BS 351.20 BS 348.2 BS 303.9 294.5 BS 277 BS BS W18236 259.5 FIGURE 2: INTERCOSTAL WEB, ATTACHMENT CLIPS, STRAP, STRINGER SPLICE AND STRINGER REINFORCEMENT AUX INTERCOSTAL - PASSENGER AIRPLANES - INSPECTION (SHEET 1 OF 6) Original Issue: June 19, 2003 Revision 2 June 24, 2010 737-53A1204 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 53 of 81 ### Page 54 (OCR) BOEING SERVICE BULLETIN 737-53A1204 ALERT ALERT TYPICAL STRINGER 303.9 STA CRACKS TYPICAL CRACKS AUXILIARY REINFORCEMENT INTERCOSTAL AND STRINGER STA 294.5 STRAP ( WD TYPICAL CRACKS INTERCOSTAL WEB A-A TYPICAL FORWARD SIDE FORWARD ENTRY DOOR AT S-16L STRINGER REINFORCEMENT 303.9 STA TYPICAL CRACKS TYPICAL CRACKS AUXILIARY INTERCOSTAL AND STRINGER STA 294.5 STRAP (1 WD 1) INTERCOSTAL WEB TYPICAL FORWARD SIDE FORWARD ENTRY DOOR AT S-14L AND S-15L B-B W18239 FIGURE 2: INTERCOSTAL WEB, ATTACHMENT CLIPS, STRAP, STRINGER SPLICE AND STRINGER REINFORCEMENT AUX INTERCOSTAL - PASSENGER AIRPLANES - INSPECTION (SHEET 2 OF 6) Original Issue: June 19, 2003 Revision 2 June 24, 2010 BOEING PROPRIETARY - 737-53A1204 Copyright © Unpublished Work - See page 1 for details. 54 of 81 ### Page 55 (OCR) BOEING SERVICE BULLETIN 737-53A1204 ALERT ALERT STA TYPICAL 303.9 CRACKS INTERCOSTAL WEB FWD (3) STRAP C-C TYPICAL CRACKS LOWER HINGE S-13L OWER INTERCOSTAL SHOW PPER INTERCOSTAL SIMILA STA TYPICAL 303.9 CRACKS STA 294.5 STRAP (3) D-D 1 INTERCOSTAL • WEB UPPER HINGE S-10L TYPICAL U51617 UPPER INTERCOSTAL SHOWN CRACKS LOWER INTERCOSTAL SIMILAR FIGURE 2: INTERCOSTAL WEB, ATTACHMENT CLIPS, STRAP, STRINGER SPLICE AND STRINGER REINFORCEMENT AUX INTERCOSTAL - PASSENGER AIRPLANES - INSPECTION (SHEET 3 OF 6) Original Issue: June 19, 2003 Revision 2 June 24, 2010 737-53A1204 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 55 of 81 ### Page 56 (OCR) BOEING SERVICE BULLETIN 737-53A1204 ALERT ALERT STA TYPICAL STRINGER 303.9 CRACKS 1) NTERCOSTAL AUXILIARY REINFORCEMENT WEE INTERCOSTAL AND STRINGER STA 294.5 FWD 1 STRAP E-E TYPICAL CRACKS TYPICAL FWD SIDE FORWARD ENTRY DOOR AT S-7L, S-8L, S-9L, S-11L, S-12L STRINGER SPLICE CHANNEL STA 360 TYPICAL F-F 1.50 - CRACKS 1.50→ WEB STA 348.20 S-15L TYPICAL CRACKS G-G S-15L SHOWN 1869884 S-14L SIMILAR AFT SIDE OF FWD ENTRY DOOR FIGURE 2: INTERCOSTAL WEB, ATTACHMENT CLIPS, STRAP, STRINGER SPLICE AND STRINGER REINFORCEMENT AUX INTERCOSTAL - PASSENGER AIRPLANES - INSPECTION (SHEET 4 OF 6) Original Issue: June 19, 2003 Revision 2 June 24, 2010 737-53A1204 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 56 of 81 ### Page 57 (OCR) BOEING SERVICE BULLETIN 737-53A1204 ALERT ALERT STA 360 D WEERCOSTAL TYPICAL CRACKS STA 348.20 S-7L FWD TEE H-H S-7L SHOWN S-8L, S-9L, S-10L, S-11L, S-12L, & S-13L SIMILAR AFT SIDE OF FWD ENTRY DOOR + FWD STRAP H-STRAP AT UPPER HINGE AND 1914906 LOWER HINGE INTERCOSTALS FIGURE 2: INTERCOSTAL WEB, ATTACHMENT CLIPS, STRAP, STRINGER SPLICE AND STRINGER REINFORCEMENT AUX INTERCOSTAL - PASSENGER AIRPLANES - INSPECTION (SHEET 5 OF 6) Original Issue: June 19, 2003 Revision 2 June 24, 2010 737-53A1204 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 57 of 81 ### Page 58 The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the numbers of parts necessary for each airplane. MORE DATAQTYIDENTIFICA- TION NAMETASKSTEP Do a Detailed Inspection of the intercostal webs, attachment clips, straps, stringer splice channel, stringer reinforcement auxiliary intercostal and stringer for cracks. (a) (b) (d) (f) 965-17685-( )IntercostalInspect1 1265-17684-( ) 965-61777-( )Stringer Splice Channel HFEC inspect both flanges of the stringer splice channel for cracks, in the indicated area on inter- costals at S-14L and S-15L, between BS 348.2 and BS 360, with 1.5 inches distance centered about the fastener attaching stringer clip to splice channel. (c) 265-61777-( )Stringer Splice Channel Inspect2 (e)290-07822-( )'H' StrapInspect3 Do a HFEC Inspection of the flange that is com- mon to the BS 348.2 frame. Note: Required for S-14L and S-15L intercostal aft side only. (c) 165-17685-( )Frame to Inter- costal Attach- ment Clip Inspect4 (a) For intercostal web, look around flanged cutout holes, tool holes, bend radius of flanges, and at edge of each corner. For each attachment clip, look at the radius area and around attaching fasteners. For strap look around all edges of parts and around attaching fasteners. For stringer splice channel look at the radius area and attaching fasteners. For stringer reinforcement auxiliary intercostal, look at angle radius and attaching fasteners. For stringer look over all the area of stringer common to intercostal. (b) Intercostals are at S-7L to S-15L, Body Station (BS) 348.2 to BS 360 and S-7L to S-16L, BS 294.5 to BS 303.9. (c) Use 737 NDT Part 6, 51-00-00, Figure 4 or Figure 23. (d) The stringer splice channels are located at at each stringer location from S-7L to S-15L BS 348.2 to BS 360. (e) Do a Detailed Inspection of the 'H' straps for cracks at upper and lower hinge locations aft of 294.5. (f) If cracks are found in S-14L and S-15L between BS 348.2 and BS 360 refer to SB 737-53A1240 R1 for repair instructions. FIGURE 2: INTERCOSTAL WEB, ATTACHMENT CLIPS, STRAP, STRINGER SPLICE AND STRINGER REINFORCEMENT AUX INTERCOSTAL - PASSENGER AIRPLANES - INSPECTION (SHEET 6 OF 6) BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 19, 2003 737-53A1204Revision 2 June 24, 2010 58 of 81 BOEING SERVICE BULLETIN 737-53A1204 ALERTALERT ### Page 59 (OCR) BOEING SERVICE BULLETIN 737-53A1204 ALERT ALERT This Figure applies only to: Group 2. FORWARD ENTRY DOOR 5-41 \ S-6L S-71 \ S-8L S-9L S-10L - S-7L S-11L S-8I S-12L S-9L S-13L S-11L S-14L S-15L S-12L Y S-13L S-16L S-14L S-15L BS S-16L 360 BS 351.20 BS 348.2 BS 303.9 294.5 BS BS 1857024 277 BS 259.5 FIGURE 3: INTERCOSTAL WEB, ATTACHMENT CLIP, STRAP AND STRINGER - CARGO AIRPLANES - INSPECTION (SHEET 1 OF 7) Original Issue: June 19, 2003 Revision 2 June 24, 2010 737-53A1204 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 59 of 81 ### Page 60 (OCR) BOEING SERVICE BULLETIN 737-53A1204 ALERT ALERT TYPICAL STRINGER CRACKS REINFORCEMENT STA 1) INTERCOSTAL TYPICAL AUXILIARY 303.9 WEB CRACKS INTERCOSTAL ANGLE AND STA STRINGER 294.5 STRAP A-A FORWARD SIDE OF FORWARD ENTRY DOOR AT S-16L 303.9 TYPICAL STA STRINGER REINFORCEMENT CRACKS TYPICAL STA AUXILIARY CRACKS 294.5 INTERCOSTAL AND STRINGER S-15L STRAP CLIP INTERCOSTAL WEB CLIP FWD SIDE OF FWD ENTRY DOOR AT S-15L B-B 1867305 FIGURE 3: INTERCOSTAL WEB, ATTACHMENT CLIP, STRAP AND STRINGER - CARGO AIRPLANES - INSPECTION (SHEET 2 OF 7) Original Issue: June 19, 2003 Revision 2 June 24, 2010 737-53A1204 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 60 of 81 The text continues at https://openairdocs.org/service-documents/boeing/737-53a1240/file/399debc0da16.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.