# Boeing Alert Service Bulletin 737-53A1328: No revision named - Rights: © The Boeing Company. Filed by the FAA in regulations.gov docket FAA-2015-0495; AD 2016-06-04 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. - Document: [Boeing Alert Service Bulletin 737-53A1328](https://openairdocs.org/service-documents/boeing/737-53a1328.md) - Title as filed: U.S. DOT/FAA - SB-737-53A1328-00 - Pages: 157 - PDF: https://openairdocs.org/files/sha256/f5/eb/f5ebc065a682cc10e3f8e9f35b11942a2b2111973813719b666891fe1aa2e10a - Page: https://openairdocs.org/service-documents/boeing/737-53a1328/file/f5ebc065a682 ## 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: 737-53A1328 Original Issue: July 22, 2014 ATA System: 5331 SUBJECT: FUSELAGE - Skin - Inspection, Preventive Modification and Repairs for Window Corners Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15 CFR 300-774). An export license may be required before it is used for development, production or use by foreign persons from specific countries. The controller of this data has the individual responsibility to abide by all export laws. 9E991ECCN: BOEING PROPRIETARY, CONFIDENTIAL AND/OR TRADE SECRET Copyright © 2014 Boeing. Unpublished Work. All Rights Reserved. Treatment of this document and its content is governed by contract with Boeing. Rights to use this document are licensed on a per aircraft basis and such rights may not be transferable. For more information, contact The Boeing Company. Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, Dreamliner, BBJ, DC-8, DC-9, DC-10, KC-10, KC-46, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8, Poseidon and Boeing liveries are all trademarks owned by The Boeing Company; and no trademark license is granted in connection with this document unless provided in writing by Boeing. Original Issue: July 22, 2014 737-53A1328 1 of 157 9.0 ### Page 2 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 2 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT BLANK PAGE ### Page 3 Table of Contents Summary ...................................................... 7 1. PLANNING INFORMATION ........................................ 1 1 A. Effectivity ............................................... 1 1 1. Airplanes ............................................ 1 1 2. Spares Affected ........................................ 1 4 B. Concurrent Requirements ...................................... 1 4 C. Reason ................................................ 1 5 D. Description .............................................. 1 5 E. Compliance .............................................. 1 6 F. Approval ............................................... 2 4 G. Manpower .............................................. 2 4 H. Weight and Balance Changes .................................... 2 7 I. Electrical Load Data ......................................... 2 7 J. References .............................................. 2 7 1. Existing Data: ......................................... 2 7 2. Data Supplied with this Service Bulletin: ........................... 2 7 3. Installation Drawings Used in the Preparation of this Service Bulletin: ........... 2 7 K. Publications Affected ........................................ 2 7 L. Interchangeability and Intermixability of Parts ........................... 2 8 M. Software Accomplishment Summary ................................ 2 8 2. MATERIAL INFORMATION ........................................ 2 9 A. Material - Price and Availability ................................... 2 9 B. Industry Support Information .................................... 2 9 C. Parts Necessary for Each Airplane ................................. 2 9 1. Kits/Parts ............................................ 2 9 2. Parts and Materials Supplied by the Operator ........................ 2 9 3. Parts Modified and Reidentified ................................ 3 0 4. Parts Removed and Not Replaced .............................. 3 0 D. Parts Necessary to Change Spares ................................. 3 0 E. Special Tooling - Price and Availability ............................... 3 1 F. Special Tooling Necessary to do this Service Bulletin ....................... 3 1 3. ACCOMPLISHMENT INSTRUCTIONS .................................. 3 3 A. GENERAL INFORMATION ..................................... 3 3 B. WORK INSTRUCTIONS ....................................... 3 4 FIGURE 1: STA 360 TO STA 540 LEFT SIDE - UPPER FORWARD AND LOWER AFT WINDOW CORNER - EXTERNAL SURFACE INSPECTION ............................ 4 8 FIGURE 2: STA 360 TO STA 540 RIGHT SIDE - UPPER FORWARD AND LOWER AFT WINDOW CORNER - EXTERNAL SURFACE INSPECTION ............................ 5 0 FIGURE 3: STA 727 TO STA 908 LEFT SIDE - LOWER FORWARD AND UPPER AFT WINDOW CORNER - EXTERNAL SURFACE INSPECTION ............................ 5 2 FIGURE 4: STA 727 TO STA 908 RIGHT SIDE - LOWER FORWARD AND UPPER AFT WINDOW CORNER - EXTERNAL SURFACE INSPECTION ............................ 5 4 FIGURE 5: STA 360 TO STA 540 LEFT SIDE - UPPER FORWARD AND LOWER AFT WINDOW CORNERS - OPEN HOLE INSPECTION ................................. 5 6 FIGURE 6: STA 360 TO STA 540 RIGHT SIDE - UPPER FORWARD AND LOWER AFT WINDOW CORNERS - OPEN HOLE INSPECTION ........................... 5 8 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 3 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 4 FIGURE 7: STA 727 TO STA 908 LEFT SIDE - LOWER FORWARD AND UPPER AFT WINDOW CORNERS - OPEN HOLE INSPECTION ................................. 6 0 FIGURE 8: STA 727 TO STA 908 RIGHT SIDE - LOWER FORWARD AND UPPER AFT WINDOW CORNERS - OPEN HOLE INSPECTION ........................... 6 2 FIGURE 9: STA 380 TO STA 500C+10 LEFT SIDE - UPPER FORWARD WINDOW CORNER REPAIR FOR SKIN CRACK [Group 1] ................................. 6 4 FIGURE 10: STA 380 TO STA 500C+10 RIGHT SIDE - UPPER FORWARD WINDOW CORNER REPAIR FOR SKIN CRACK [Group 1] ................................. 6 9 FIGURE 11: STA 380 TO STA 500C+10 LEFT SIDE - LOWER AFT WINDOW CORNER REPAIR FOR SKIN CRACK [Group 1] ....................................... 7 4 FIGURE 12: STA 380 TO STA 500C+10 RIGHT SIDE - LOWER AFT WINDOW CORNER REPAIR FOR SKIN CRACK [Group 1] .................................... 7 9 FIGURE 13: STA 380 AND STA 500C+10.00 LEFT SIDE - UPPER FORWARD AND LOWER AFT WINDOW CORNER REPAIR FOR SKIN CRACK [Group 1] ...................... 8 4 FIGURE 14: STA 380 AND STA 500C+10.00 RIGHT SIDE - UPPER FORWARD AND LOWER AFT WINDOW CORNER REPAIR FOR SKIN CRACK [Group 1] ...................... 8 9 FIGURE 15: STA 727E +10.45 TO STA 897.45 LEFT SIDE - UPPER AFT WINDOW CORNER REPAIR FOR SKIN CRACK [Group 1] .................................... 9 4 FIGURE 16: STA 727E +10.45 TO STA 897.45 RIGHT SIDE - UPPER AFT WINDOW CORNER REPAIR FOR SKIN CRACK [Group 1] ................................. 9 9 FIGURE 17: STA 727E+10.45 TO STA 897.45 LEFT SIDE - LOWER FORWARD WINDOW CORNER REPAIR FOR SKIN CRACK [Group 1] ............................ 1 0 4 FIGURE 18: STA 727E+10.45 TO STA 897.45 RIGHT SIDE - LOWER FORWARD WINDOW CORNER REPAIR FOR SKIN CRACK [Group 1] ............................ 1 0 9 FIGURE 19: STA 727E TO STA 897.45 LEFT SIDE - UPPER AFT AND LOWER FORWARD WINDOW CORNER REPAIR FOR SKIN CRACK [Group 1] ...................... 1 1 4 FIGURE 20: STA 727E TO STA 897.45 RIGHT SIDE - UPPER AFT AND LOWER FORWARD WINDOW CORNER REPAIR FOR SKIN CRACK [Group 1] ...................... 1 1 9 FIGURE 21: STA 380 TO STA 500C+10.00 LEFT SIDE - UPPER FORWARD WINDOW CORNER - POST REPAIR INSPECTION [Group 1] ............................... 1 2 4 FIGURE 22: STA 380 TO STA 500C+10.00 RIGHT SIDE - UPPER FORWARD WINDOW CORNER - POST REPAIR INSPECTION [Group 1] ............................... 1 2 6 FIGURE 23: STA 380 TO STA 500C+10.00 LEFT SIDE - LOWER AFT WINDOW CORNER - POST REPAIR INSPECTION [Group 1] .................................... 1 2 8 FIGURE 24: STA 380 TO STA 500C+10.00 RIGHT SIDE - LOWER AFT WINDOW CORNER - POST REPAIR INSPECTION [Group 1] .................................... 1 3 0 FIGURE 25: STA 380 TO STA 500C+10.00 LEFT SIDE - UPPER FORWARD AND LOWER AFT WINDOW CORNER - POST REPAIR INSPECTION [Group 1] .................... 1 3 2 FIGURE 26: STA 380 TO STA 500C+10.00 RIGHT SIDE - UPPER FORWARD AND LOWER AFT WINDOW CORNER - POST REPAIR INSPECTION [Group 1] .................... 1 3 4 FIGURE 27: STA 727E+10.45 TO STA 897.45 LEFT SIDE - UPPER AFT WINDOW CORNER - POST REPAIR INSPECTION [Group 1] ............................... 1 3 6 FIGURE 28: STA 727E+10.45 TO STA 897.45 RIGHT SIDE - UPPER AFT WINDOW CORNER - POST REPAIR INSPECTION [Group 1] ............................... 1 3 8 FIGURE 29: STA 727E TO STA 897.45 LEFT SIDE - LOWER FORWARD WINDOW CORNER - POST REPAIR INSPECTION [Group 1] ............................... 1 4 0 FIGURE 30: STA 727E TO STA 897.45 RIGHT SIDE - LOWER FORWARD WINDOW CORNER - POST REPAIR INSPECTION [Group 1] ............................... 1 4 2 FIGURE 31: STA 727E+10.45 TO STA 897.45 LEFT SIDE - UPPER AFT AND LOWER FORWARD WINDOW CORNER - POST REPAIR INSPECTION [Group 1] .................... 1 4 4 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 4 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 5 FIGURE 32: STA 727E+10.45 TO STA 897.45 RIGHT SIDE - UPPER AFT AND LOWER FORWARD WINDOW CORNER - POST REPAIR INSPECTION [Group 1] .............. 1 4 6 FIGURE 33: STA 360 TO STA 540 LEFT SIDE - UPPER FORWARD AND LOWER AFT WINDOW CORNER - INSPECTION ........................................ 1 4 8 FIGURE 34: STA 360 TO STA 540 RIGHT SIDE - UPPER FORWARD AND LOWER AFT WINDOW CORNER - INSPECTION ........................................ 1 5 0 FIGURE 35: STA 727 TO STA 908 LEFT SIDE - UPPER FORWARD AND LOWER AFT WINDOW CORNER - INSPECTION ........................................ 1 5 2 FIGURE 36: STA 727 TO STA 908 RIGHT SIDE - UPPER FORWARD AND LOWER AFT WINDOW CORNER - INSPECTION ........................................ 1 5 4 APPENDIX A: WINDOW FRAME EDGE MARGIN REQUIREMENTS AND FASTENER GROUP IDENTIFICATION ...................................... 1 5 6 APPENDIX B: FUEL BURN AND PERFORMANCE PENALTIES ..................... 1 5 7 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 5 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 6 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 6 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT BLANK PAGE ### Page 7 Commercial Airplanes 737 Service Bulletin ALERT SummaryNumber: 737-53A1328Original Issue: July 22, 2014 ATA System: 5331 SUBJECT: FUSELAGE - Skin - Inspection, Preventive Modification and Repairs for Window Corners THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH 1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO THE NEW OWNER. CONCURRENT REQUIREMENTS None. BACKGROUND This service bulletin gives instructions to inspect for cracks and accomplish a preventive modification and/or limited repairs at fastener locations in window corners of the window belt area between STA 360 to STA 540 and STA 727 to STA 908, left and right side at and between stringers S-11 and S-13. If not corrected, the cracking around the fastener holes could cause multiple window corner skin cracks which can result in rapid decompression and loss of structural integrity. Aging aircraft investigations by Boeing into 737-300/-400/-500 aircraft with solid skin window belt panels and cycles between 37,842 and 49,050 have discovered cracks at some fastener locations in the window corners of the window belt. This bulletin provides instructions to inspect window corners for cracks and if any crack is found remove by oversizing the hole and/or installing a repair in limited areas. An optional preventive modification is provided for all window corner locations but is not mandated. Boeing Service Related Problem (SRP) 737-SRP-53-0363 is related to this service bulletin. Boeing did a fuel burn penalty analysis on the changes given in this service bulletin. Refer to APPENDIX B for the analysis. This table is provided to operators for planning purposes only. Refer to the applicable sections for more information. ReferenceAffectedPlanning Data Paragraph 1.A.2., Spares AffectedNoSpares Affected Paragraph 1.E., Compliance and Paragraph 1.F., Approval YesAD Related Paragraph 1.H., Weight and Balance ChangesYesWeight and Balance Change Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 7 of 157 ### Page 8 ReferenceAffectedPlanning Data Paragraph 1.I., Electrical Load DataNoElectrical Load Changed Paragraph 1.K., Publications AffectedNoPublications Affected Paragraph 1.K., Publications AffectedYesAirplane Flight Operations Affected (Flight Crew Operations Manual and/or FAA Approved Air- plane Flight Manual) Paragraph 2.C.1., Kits/PartsNoKits/Parts Required Paragraph 2.C.2., Parts and Materials Supplied by the Operator YesOperator Supplied Parts/Material Paragraph 2.F., Special Tooling Necessary to do this Service Bulletin NoSpecial Tooling Required The Window Corner locations have been determined to be structure that is susceptible to Widespread Fatigue Damage (WFD). ACTION Do the inspections or preventive modification as follows: Group 1: Do an external surface High Frequency Eddy Current (HFEC) inspection of the skin at the twelve fastener locations at the upper forward and lower aft corners of each window between STA 360 and STA 540 and at the upper aft and lower forward corners of each window between STA 727 and STA 908. If no cracks are found, do repeat inspections or do the preventive modification. If any crack is found at any of the three corner fastener hole locations (refer to Appendix A) between STA 380 to STA 500C+10.00 or between STA 727E+10.45 and STA 897.45 and is within maximum trim out limits, do a repair of the window corner. If any crack is found within the oversize limits at any hole during the modification, accomplish crack clean up instructions and complete modification. If any crack beyond the maximum oversize hole limit is found in the skin outside the area of the three corner fastener hole locations at any station contact Boeing for repair instructions and do the repair. If any crack beyond the maximum oversize hole limit is found in the skin at any of the three corner fastener hole locations between STA 360 to STA 380, STA 500C+10.00 to STA 540, STA 727 to STA 727E+10.45 and between STA 897.45 to STA 908, contact Boeing for repair instructions and do the repair. If any crack or corrosion is found during accomplishment of the repair contact Boeing for repair instructions and do the repair. Do a post repair inspection around each fastener location in the repaired area. If any crack is found, contact Boeing for repair instructions and do the repair. Group 2: Do an external surface HFEC inspection of the skin at the twelve fastener locations at the upper forward and lower aft corners of each window between STA 360 and STA 540 and at the upper aft and lower forward corners of each window between STA 727 and STA 908. If no cracks are found, do repeat inspections or do the preventive modification. If any crack is found within the oversize limits at any hole during the modification, accomplish crack clean up instructions and complete modification. If any crack beyond the maximum oversize hole limit is found in the skin at any of the twelve fastener locations which includes the three corner fasteners between STA 360 to STA 540 and STA 727 to STA 908, contact Boeing for repair instructions and do the repair. EFFECTIVITY 737-300/-400/-500 Airplanes. Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplanes. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 8 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 9 COMPLIANCE The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin mandatory. Refer to Paragraph 1.E., Compliance. INDUSTRY SUPPORT INFORMATION Boeing warranty remedies are not available for the configuration changes, inspection, and/or repair procedures given in this service bulletin. MANPOWER Refer to Paragraph 1.G., Manpower. MATERIAL INFORMATION None. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 9 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 10 (OCR) BOEING SERVICE BULLETIN 737-53A1328 ALERT ALERT STA 1016 STA 259.50 DO EXTERNAL SURFACE HFEC INSPECTIONS OF THE SKIN AT UPPER AFT AND LOWER FORWARD WINDOW CORNERS FROM STA 727 TO STA 908. DO REPEAT INSPECTIONS, PREVENTIVE MODIFICATION OR REPAIR. Л 259.50 STA STA 360 STA 540 STA 727 STA 908 1016 STA S-26R BL 0 S-19R IS-25R S-24R • S-20R S-19R 00000000000. S-14R S-14R S-10R S-10R S-4R S-4R S-4L | S-4L S-10L S-14L S-10L S-19L 800000000000 S-14L S-24L - S-20L 00 S-19L - S-25L BL O S-26L DO EXTERNAL SURFACE HFEC INSPECTIONS OF THE SKIN AT LOWER AFT AND UPPER FORWARD WINDOW CORNERS FROM STA 360 TO STA 540. DO REPEAT INSPECTIONS 2220210 PREVENTIVE MODIFICATION OR REPAIR. Original Issue: July 22, 2014 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished 737-53A1328 Work - See page 1 for details. 10 of 157 ### Page 11 Commercial Airplanes 737 Service Bulletin ALERT Number: 737-53A1328 Original Issue: July 22, 2014 ATA System: 5331 SUBJECT: FUSELAGE - Skin - Inspection, Preventive Modification and Repairs for Window Corners 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 737-300 airplanes, line numbers 2567 and on. These airplanes have instructions for an external doubler repair. -1 737-400/-500 airplanes, line numbers 2566 and on. These airplanes do not have instructions for an external doubler repair. -2 Airplane Models: 737-300, 737-400, 737-500 GroupVariable Number 2PJ553 - PJ561 2PJ601 - PJ615 2PJ811 2PJ816 - PJ817 1PM548 - PM550 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 11 of 157 ### Page 12 GroupVariable Number 1PP518 - PP520 1PP876 - PP877 1PQ297 - PQ299 1PQ345 - PQ348 1PQ370 - PQ373 1PQ391 - PQ395 1PQ409 - PQ410 1PQ414 - PQ418 1PQ431 - PQ438 1PQ447 - PQ448 1PQ451 1PQ454 1PQ474 - PQ475 1PQ772 1PQ933 - PQ935 1PQ951 1PQ971 - PQ997 1PR001 - PR017 1PR021 - PR034 1PR041 - PR045 1PR061 - PR072 1PR077 - PR082 1PR091 - PR092 1PR096 1PR101 1PR121 - PR122 1PR131 - PR132 1PR141 - PR143 1PR161 - PR172 1PR181 1PS617 - PS630 1PS704 - PS706 1PS763 - PS799 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 12 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 13 GroupVariable Number 1PS811 1PS836 - PS837 1PS841 - PS846 1PS851 - PS852 1PS856 1PS861 - PS863 1PS866 - PS868 1PS871 - PS874 1PS896 - PS897 1PS901 - PS941 1PS956 - PS957 1PS961 - PS963 1PS971 - PS978 2PT012 - PT015 2PT029 - PT031 2PT126 - PT138 2PT188 2PT307 - PT309 2PT513 - PT517 2PT585 - PT586 2PT643 - PT644 2PT656 2PT681 - PT685 2PT716 - PT717 2PT721 - PT725 2PT801 - PT834 2PT851 - PT854 2PT871 - PT886 2PT901 - PT930 2PT971 - PT973 2PT981 - PT985 2PT996 2PU301 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 13 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 14 GroupVariable Number 2PU311 - PU313 2PV204 - PV209 2PV226 - PV229 2PV284 - PV287 2PV296 2PV301 - PV302 2PV351 2PV356 - PV357 2PW086 - PW088 2PW168 - PW171 2PW246 - PW252 2PW262 - PW264 2PW271 - PW276 2PW285 - PW292 2PW401 - PW408 2PW411 - PW418 2PW421 - PW424 2PW431 - PW435 2PW441 - PW450 2PW521 - PW522 2PW524 - PW525 2PW527 - PW530 2PW547 - PW550 2PW621 - PW622 2PW635 - PW637 2PW831 2PW851 - PW856 2. Spares Affected None. B. Concurrent Requirements None. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 14 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 15 C. Reason This service bulletin gives instructions to inspect for cracks and accomplish a preventive modification and/or limited repairs at fastener locations in window corners of the window belt area between STA 360 to STA 540 and STA 727 to STA 908, left and right side at and between stringers S-11 and S-13. If not corrected, the cracking around the fastener holes could cause multiple window corner skin cracks which can result in rapid decompression and loss of structural integrity. Aging aircraft investigations by Boeing into 737-300/-400/-500 aircraft with solid skin window belt panels and cycles between 37,842 and 49,050 have discovered cracks at some fastener locations in the window corners of the window belt. This bulletin provides instructions to inspect window corners for cracks and if any crack is found remove by oversizing the hole and/or installing a repair in limited areas. An optional preventive modification is provided for all window corner locations but is not mandated. Boeing Service Related Problem (SRP) 737-SRP-53-0363 is related to this service bulletin. Boeing did a fuel burn penalty analysis on the changes given in this service bulletin. Refer to APPENDIX B for the analysis. D. Description Do the inspections or preventive modification as follows: Group 1: Do an external surface High Frequency Eddy Current (HFEC) inspection of the skin at the twelve fastener locations at the upper forward and lower aft corners of each window between STA 360 and STA 540 and at the upper aft and lower forward corners of each window between STA 727 and STA 908. If no cracks are found, do repeat inspections or do the preventive modification. If any crack is found at any of the three corner fastener hole locations (refer to Appendix A) between STA 380 to STA 500C+10.00 or between STA 727E+10.45 and STA 897.45 and is within maximum trim out limits, do a repair of the window corner. If any crack is found within the oversize limits at any hole during the modification, accomplish crack clean up instructions and complete modification. If any crack beyond the maximum oversize hole limit is found in the skin outside the area of the three corner fastener hole locations at any station contact Boeing for repair instructions and do the repair. If any crack beyond the maximum oversize hole limit is found in the skin at any of the three corner fastener hole locations between STA 360 to STA 380, STA 500C+10.00 to STA 540, STA 727 to STA 727E+10.45 and between STA 897.45 to STA 908, contact Boeing for repair instructions and do the repair. If any crack or corrosion is found during accomplishment of the repair contact Boeing for repair instructions and do the repair. Do a post repair inspection around each fastener location in the repaired area. If any crack is found, contact Boeing for repair instructions and do the repair. Group 2: Do an external surface HFEC inspection of the skin at the twelve fastener locations at the upper forward and lower aft corners of each window between STA 360 and STA 540 and at the upper aft and lower forward corners of each window between STA 727 and STA 908. If no cracks are found, do repeat inspections or do the preventive modification. If any crack is found within the oversize limits at any hole during the modification, accomplish crack clean up instructions and complete modification. If any crack beyond the maximum oversize hole limit is found in the skin at any of the twelve fastener locations which includes the three corner fasteners between STA 360 to STA 540 and STA 727 to STA 908, contact Boeing for repair instructions and do the repair. The work in this service bulletin is done in the maintenance zone(s) given below. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 15 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 16 Group 1: Affected Maintenance Zones ZoneModel 101, 102, 107, 108737-300 Group 2: Affected Maintenance Zones ZoneModel 101, 102, 107, 108737-400, 737-500 E. Compliance The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive (AD) related to this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin mandatory. NOTE: The damage tolerance inspections specified in Tables 3 and 8 below may be used in support of compliance with 14 Code of Federal Regulations, Section 121.1109 or 129.109. Do the required actions in accordance with Paragraph 3.B., Work Instructions. Group 1: Table 1 - Window Corner - Inspection and Repair Repeat Interval (Not to Exceed) Compliance Time (Whichever oc- curs later) ActionCondition -Within 3,000 flight cycles af- ter the original issue date of this service bulletin (a) (b) Before 50,000 total flight cycles (a) (b) Do PART 1: WIN- DOW CORNER EX- TERNAL SURFACE HFEC INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 908. (a) (b) All airplanes 7,000 flight cycles (a) (b) (c) Within 7,000 flight cycles after accom- plishment of the initial inspection. (a) (b) (c) Repeat PART 1: WINDOW CORNER EXTERNAL SUR- FACE HFEC IN- SPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 908. (a) (b) (c) CONDITION 1: No crack found in the skin at any of the twelve fastener hole locations common to any window corner between STA 360 to STA 540 or between STA 727 to STA 908 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 16 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 17 Group 1: Table 1 - Window Corner - Inspection and Repair Repeat Interval (Not to Exceed) Compliance Time (Whichever oc- curs later) ActionCondition -Before further flightDo PART 6: WIN- DOW CORNER CRACK REPAIR (c) CONDITION 2: Any crack found in the skin at any of the three corner fastener hole locations be- tween STA 380 to STA 500C+10.00 or between STA 727E+10.45 to STA 897.45 and is within the maximum trimout limits. (d) -Before further flightContact Boeing for repair instructions and do the repair. CONDITION 3: Any crack found in the skin at any of the three corner fastener hole locations be- tween STA 360 to STA 380, STA 500C+10.00 to STA 540, STA 727 to STA 727E+10.45 or be- tween STA 897.45 to STA 908 OR Any crack found in the skin at any of the three corner fastener hole locations that is not within the maxi- mum trimout limits. (d) -Before further flightContact Boeing for repair instructions and do the repair. CONDITION 4: Any crack found in the skin that is not at the three corner fastener hole locations be- tween STA 360 to STA 540, and STA 727 to STA 908. (d) (a) If any Boeing ODA approved repair via FAA Form 8100-9 was installed to eliminate cracking that was previously found, further inspections in the window corner are not required at the repaired location. (b) Accomplishment of the preventive modification in accordance with this service bulletin is terminating action for the initial and repeat inspections at the modified location only. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 17 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 18 Group 1: Table 1 - Window Corner - Inspection and Repair Repeat Interval (Not to Exceed) Compliance Time (Whichever oc- curs later) ActionCondition (c) Accomplishment of the repair in accordance with this service bulletin is terminating action for the repeat inspections at the repaired location only. (d) Refer to APPENDIX A for identification of the three corner fasteners. Group 2: Table 2 - Window Corner - Inspection Repeat Interval (Not to Exceed) Compliance Time (Whichever oc- curs later) ActionCondition -Within 3,000 flight cycles af- ter the original issue date of this service bulletin (a) (b) Before 50,000 total flight cycles (a) (b) Do PART 1: WIN- DOW CORNER EX- TERNAL SURFACE HFEC INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 908. (a) (b) All airplanes 7,000 flight cycles (a) (b)Within 7,000 flight cycles after accom- plishment of the initial inspection. (a) (b) Repeat PART 1: WINDOW CORNER EXTERNAL SUR- FACE HFEC IN- SPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 908. (a) (b) CONDITION 1: No crack found in the skin at any of the twelve fastener hole locations common to any window corner between STA 360 to STA 540 or between STA 727 to STA 908 -Before further flightContact Boeing for repair instructions and do the repair. CONDITION 5: Any crack found in the skin at any of the twelve fastener hole locations common to any window corner between STA 360 to STA 540, or between STA 727 to STA 908. (a) If any Boeing ODA approved repair via FAA Form 8100-9 was installed to eliminate cracking that was previously found, further inspections in the window corner are not required at the repaired location. (b) Accomplishment of the preventive modification in accordance with this service bulletin is terminating action for the initial and repeat inspections at the modified location only. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 18 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 19 Group 1: Table 3 - Window Corner - Post Repair Inspections Repeat Inter- val (Not to Exceed) Compliance TimeActionCondition 2,800 flight cycles Within 55,000 flight cy- cles after accomplish- ment of the repair Do external LFEC and HFEC inspections for cracks in the skin and doubler in accor- dance with Accomplishment Instructions 3.B., PART 8, steps 3 and 4. Airplanes that have accom- plished the repair in accor- dance with Part 6 of this service bulletin. -Before further flightContact Boeing for repair instructions and do the repair. Any crack found Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 19 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 20 Group 1: Table 4 - Window Frame - Inspection of Frames with Short Edge Margins Repeat Inter- val (Not to Exceed) Compliance TimeActionCondition -Before further flight.Do a window frame replacement in accor- dance with Accomplishment Instructions 3.B., PART 7. Repaired or modified areas with edge margin less than 1.2D at Group A fastener hole locations (a) (b) 4,000 flight cycles Within 16,000 flight cy- cles after accomplish- ment of the repair or preventive modification Do an internal detailed inspection of the window forging around the fastener collars for cracks in accordance with Accomplish- ment Instructions 3.B., PART 8, step 5. Repaired or modified areas with edge margin greater than or equal to 1.2D and less than 1.5D at Group A fastener hole locations (a) (b) (c) -Before further flight.Do a window frame replacement in accor- dance with Accomplishment Instructions 3.B., PART 7. Repaired or modified areas with edge margin less than 1.35D at Group B fastener hole locations (a) (b) 2,000 flight cycles Within 24,000 flight cy- cles after accomplish- ment of the repair or preventive modification Do an internal detailed inspection of the window forging around the fastener collars for cracks in accordance with Accomplish- ment Instructions 3.B., PART 8, step 6. Repaired or modified areas with edge margin greater than or equal to 1.35D and less than 1.5D at Group B fastener hole locations (a) (b) (c) -Before further flightContact Boeing for repair instructions and do the repair. Any crack found (a) Edge margin is defined as the distance between the center of the hole and the edge of the part. D is defined as the final fastener hole diameter of the oversized hole. (b) Refer to APPENDIX A for fastener group definition. (c) Repaired or modified areas with edge margin between 1.5D and 2D is considered structurally satisfactory without any special inspections beyond normal maintenance. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 20 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 21 Group 2: Table 5 - Window Frame - Inspections of Frames with Short Edge Margins Repeat Inter- val (Not to Exceed) Compliance TimeActionCondition -Before further flight.Do a window frame replacement in accor- dance with Accomplishment Instructions 3.B., PART 7. Repaired or modified areas with edge margin less than 1.2D at Group A fastener hole locations (a) (b) 4,000 flight cycles Within 16,000 flight cy- cles after accomplish- ment of the preventive modification Do an internal detailed inspection of the window forging around the fastener collars for cracks in accordance with Accomplish- ment Instructions 3.B., PART 8, step 5. Modified areas with edge margin greater than or equal to 1.2D and less than 1.5D at Group A fas- tener hole locations (a) (b) (c) -Before further flight.Do a window frame replacement in accor- dance with Accomplishment Instructions 3.B., PART 7. Repaired or modified areas with edge margin less than 1.35D at Group B fastener hole locations (a) (b) 2,000 flight cycles Within 24,000 flight cy- cles after accomplish- ment of the preventive modification Do an internal detailed inspection of the window forging around the fastener collars for cracks in accordance with Accomplish- ment Instructions 3.B., PART 8, step 6. Modified areas with edge margin greater than or equal to 1.35D and less than 1.5D at Group B fas- tener hole locations (a) (b) (c) Before further flightContact Boeing for repair instructions and do the repair. Any crack found (a) Edge margin is defined as the distance between the center of the hole and the edge of the part. D is defined as the final fastener hole diameter of the oversized hole. (b) Refer to APPENDIX A for fastener group definition. (c) Repaired or modified areas with edge margin between 1.5D and 2D is considered structurally satisfactory without any special inspections beyond normal maintenance. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 21 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 22 Group 1: Table 6 - Window Corner - Economic Inspection and Repair Repeat Inter- val (Not to Ex- ceed) Compliance TimeActionCondition -Before 30,000 total flight cycles (a) (b) (c) Do PART 1: WINDOW CORNER EXTERNAL SURFACE HFEC INSPEC- TION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 908. (b) (c) All airplanes 7,000 flight cy- cles (a) (b) (c) (d) Within 7,000 flight cycles after accom- plishment of the ini- tial inspection. (a) (b) (c) (d) Repeat PART 1: WINDOW CORNER EXTERNAL SURFACE HFEC INSPEC- TION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 908. (b) (c) (d) CONDITION 1: No crack found in the skin at any of the twelve fastener hole locations common to any window corner between STA 360 to STA 540 or between STA 727 to STA 908. -Before further flight.Do PART 6: WINDOW CORNER CRACK REPAIR (d) CONDITION 2: Any crack found in the skin at any of the three corner fastener hole loca- tions between STA 380 to STA 500C+10.00 or between STA 727E+10.45 to STA 897.45 and crack is within the maximum trimout limits. (e) -Before further flight.Contact Boeing for repair instructions and do the re- pair. CONDITION 3: Any crack found in the skin at any of the three corner fastener hole loca- tions between STA 360 to STA 380, STA 500C+10.00 to STA 540, STA 727 to STA 727E+10.45 or between STA 897.45 to STA 908 OR Any crack found in the skin at any of the three corner fastener hole locations that is not within the maximum trimout limits. (e) -Before further flight.Contact Boeing for repair instructions and do the re- pair. CONDITION 4: Any crack found in the skin that is not at the three corner fastener hole locations between STA 360 to STA 540, and STA 727 to STA 908. (e) (a) It is recommended to do the inspection at this compliance time to increase the chances that the crack will be within the limits of the preventive modification and repair of the skin will not be required. Accomplishing this inspection satisfies the requirements of Table 1. (b) If any Boeing ODA approved repair via FAA Form 8100-9 was installed to eliminate cracking that was previously found, further inspections in the window corner are not required at the repaired location. (c) Accomplishment of the preventive modification in accordance with this service bulletin is terminating action for the initial and repeat inspections at the modified location only. (d) Accomplishment of the repair in accordance with this service bulletin is terminating action for the repeat Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 22 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 23 Group 1: Table 6 - Window Corner - Economic Inspection and Repair Repeat Inter- val (Not to Ex- ceed) Compliance TimeActionCondition inspections at the repaired location only. (e) Refer to APPENDIX A for identification of the three corner fasteners. Group 2: Table 7 - Window Corner - Economic Inspection Repeat Inter- val (Not to Ex- ceed) Compliance TimeActionCondition -Before 30,000 total flight cycles (a) (b) (c) Do PART 1: WINDOW COR- NER EXTERNAL SURFACE HFEC INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 908. (b) (c) All airplanes 7,000 flight cy- cles (a) (b) (c) Within 7,000 flight cycles after accomplishment of the initial inspection. Repeat PART 1: WINDOW CORNER EXTERNAL SUR- FACE HFEC INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 908. (b) (c) CONDITION 1: No crack found in the skin at any of the twelve fastener hole locations common to any window corner between STA 360 to STA 540 or between STA 727 to STA 908. (a) (b) (c) -Before further flight.Contact Boeing for repair instruc- tions and do the repair. CONDITION 5: Any crack found in the skin at any of the twelve fastener hole locations common to any window corner between STA 360 to STA 540 or between STA 727 to STA 908. (a) It is recommended to do the inspection at this compliance time to increase the chances that the crack will be within the limits of the preventive modification and repair of the skin will not be required. Accomplishing this inspection satisfies the requirements of Table 2. (b) If any Boeing ODA approved repair via FAA Form 8100-9 was installed to eliminate cracking that was previously found, further inspections in the window corner are not required at the repaired location. (c) Accomplishment of the preventive modification in accordance with this service bulletin is terminating action for the initial and repeat inspections at the modified location only. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 23 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 24 Table 8 - Window Corner - Post Modification Inspections Repeat Inter- val (Not to Exceed) Compliance TimeActionCondition 5,000 flight cycles Within 56,000 flight cy- cles after accomplish- ment of the repair or preventive modification Do an external surface HFEC inspection for cracks around the fasteners in accordance with Accomplishment Instructions 3.B., PART 8, step 2. Airplanes that have accom- plished the preventive modification in accordance with PART 3 or oversize hole repair (without an ex- ternal repair) in accor- dance with PART 5. -Before further flightContact Boeing for repair instructions and do the repair. Any crack found. 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. G. Manpower The table below shows an estimate of the task hours necessary to do this inspection and modification for each airplane. This estimate is for direct labor only, done by an experienced crew. Adjust the estimate with operator task hour data if necessary. The estimate does not include lost time. These are some examples of lost time:  Time to adjust to the workplace  Time to schedule the work  Time to inspect the work  Time to cure the materials  Time to make the parts  Time to find the tools. Table 1: Open/Close Access and Test Elapsed HoursTask HoursNumber of PersonsTask 109.301093.0010Open Access 109.301093.0010Close Access 25.00100.004Test Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 24 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 25 Table 1: Open/Close Access and Test Elapsed HoursTask HoursNumber of PersonsTask 243.602286.00TOTAL FOR EACH AIRPLANE Table 2: External Surface Inspection Elapsed HoursTask HoursNumber of PersonsTask 3.006.002FIGURE 1 3.006.002FIGURE 2 3.507.002FIGURE 3 3.507.002FIGURE 4 13.0026.00TOTAL FOR EACH AIRPLANE Table 3: Preventive Modification Elapsed HoursTask HoursNumber of PersonsTask 4.5018.004FIGURE 5 4.5018.004FIGURE 6 5.2521.004FIGURE 7 5.2521.004FIGURE 8 7.5030.004Install Fasteners 27.00108.00TOTAL FOR EACH AIRPLANE Group 1: Table 4: Repair Elapsed HoursTask HoursNumber of PersonsTask 9.159.151FIGURE 9 (a) 9.159.151FIGURE 10 (a) 9.159.151FIGURE 11 (a) 9.159.151FIGURE 12 (a) 9.1518.302FIGURE 13 (a) 9.1518.302FIGURE 14 (a) 9.159.151FIGURE 15 (a) 9.159.151FIGURE 16 (a) 9.159.151FIGURE 17 (a) 9.159.151FIGURE 18 (a) Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 25 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 26 Group 1: Table 4: Repair Elapsed HoursTask HoursNumber of PersonsTask 9.1518.302FIGURE 19 (a) 9.1518.302FIGURE 20 (a) (a) Estimates given are per window requiring this task and therefore total hours are not given. Group 1: Table 5: Post Repair and Post Preventive Modification Inspections Elapsed HoursTask HoursNumber of PersonsTask 0.600.601FIGURE 21 (a) 0.600.601FIGURE 22 (a) 0.600.601FIGURE 23 (a) 0.600.601FIGURE 24 (a) 1.201.201FIGURE 25 (a) 1.201.201FIGURE 26 (a) 0.600.601FIGURE 27 (a) 0.600.601FIGURE 28 (a) 0.600.601FIGURE 29 (a) 0.600.601FIGURE 30 (a) 1.201.201FIGURE 31 (a) 1.201.201FIGURE 32 (a) 3.006.002FIGURE 33 (a) 3.006.002FIGURE 34 (a) 3.507.002FIGURE 35 (a) 3.507.002FIGURE 36 (a) (a) Estimates given are per window requiring this task and therefore total hours are not given. Group 2: Table 6: Post Preventive Modification Inspections Elapsed HoursTask HoursNumber of PersonsTask 3.006.002FIGURE 33 (a) 3.006.002FIGURE 34 (a) 3.507.002FIGURE 35 (a) Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 26 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 27 Group 2: Table 6: Post Preventive Modification Inspections Elapsed HoursTask HoursNumber of PersonsTask 3.507.002FIGURE 36 (a) (a) Estimates given are per window requiring this task and therefore total hours are not given. H. Weight and Balance Changes None. I. Electrical Load Data Not changed. J. References 1. Existing Data: a. Boeing Service Related Problem (SRP) 737-SRP-53-0363 b. Standard Overhaul Practices Manual (SOPM) 20-20-11, 20-41-02, 20-41-05, 20-43-03, 20-50-01 c. 737 Non-Destructive Testing (NDT) Manual Part 6, 51-00-00, Part 6, 53-30-00 d. 737-300/400/500 Aircraft Maintenance Manual (AMM) 05-51-91, 21-23-25, 25-21-25, 25-21-31, 25-21-35, 25-21-39, 25-21-45, 25-21-46, 25-21-71, 25-22-00, 25-23-61, 25-24-00, 25-24-15, 25-24-31, 25-31-11, 25-31-31, 25-31-41, 25-31-83, 25-31-87, 51-21-00, 56-21-00 e. 737-300 Structural Repair Manual (SRM) 51-10-01, 51-40-05, 51-40-08, 56-20-02 f. 737-400 Structural Repair Manual (SRM) 51-10-01, 51-40-05, 51-40-08, 56-20-02 g. 737-500 Structural Repair Manual (SRM) 51-10-01, 51-40-05, 51-40-08, 56-20-02 2. Data Supplied with this Service Bulletin: None. 3. Installation Drawings Used in the Preparation of this Service Bulletin: None. K. Publications Affected 1. Publications: Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 27 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 28 Chapter-SectionPublication APPENDIX 51737 FAA Approved Airplane Flight Manual 2. Damage Tolerance Based Structural Inspections: Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the Maintenance Program. This service bulletin affects FCS. DTI requirements for the structure affected are contained in Paragraph 1.E., Compliance of this service bulletin. L. Interchangeability and Intermixability of Parts Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts. M. Software Accomplishment Summary Not affected. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 28 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 29 2. MATERIAL INFORMATION A. Material - Price and Availability None. B. Industry Support Information Boeing warranty remedies are not available for the configuration changes, inspection, and/or repair procedures given in this service bulletin. C. Parts Necessary for Each Airplane 1. Kits/Parts None. 2. Parts and Materials Supplied by the Operator The following parts or materials are necessary to do the change in this service bulletin. Parts and materials in the manuals given in Paragraph 1.J., References, can also be necessary. Examine operator part and material supply to make sure all necessary parts and materials are available. NotesNameQTYPart Number / Specification -Window Forging165-45785-521 (a)Window Forging165-45785-9 (b)Window Forging165-45785U9 (e)Hi-Lok24BACB30FP8A( ) (e)Hi-Lok24BACB30FP10A( ) (c)Sealant1/2 Pint BMS 3-23, Type II (c)Sealant1/2 Pint BMS 5-95, Class B-1/2 (c)Primer1/2 Pint BMS 10-11, Type I (c)Primer1/2 Pint BMS 10-11, Type III (d)Chemical Conversion Coating1/2 Pint Type 2, Class A (a) 65-45785-9 is identical to 65-45785-521 except finish. (b) 65-45785U9 is identical to 65-45785-9 except all pilot holes are omitted. (c) See the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier data. (d) Refer to SOPM 20-43-03 for supplier data. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 29 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 30 NotesNameQTYPart Number / Specification (e) Quantity of fasteners required to accomplish the preventive modification for each window. Group 1: NotesNameQTYPart Number / Specification (a)Bolt7BACB30FQ8A( ) (a)Bolt7BACB30FQ10A( ) (a)Bolt10BACB30KF6A( ) (a)Rivet57BACR15GF6D( ) (a)Collar10BACC30M6 (a)Collar7BACC30M8 (a)Collar7BACC30M10 (d)Repair Doubler12024-T3 clad sheet, 0.09 x 12.00 x 12.00 (d)Repair Filler12024-T3 clad sheet, 0.08 x 3.00 x 3.00 (b)Sealant1 PintBMS 3-23, Type II (b)Sealant1 PintBMS 5-95, Class B-1/2 (b)Primer1 PintBMS 10-11, Type I (b)Primer1 PintBMS 10-11, Type III (c)Chemical Conversion Coating1 PintType 2, Class A (a) Quantity of fasteners required to accomplish each window corner repair. (b) See the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier data. (c) Refer to SOPM 20-43-03 for supplier data. (d) Quantity of material required for each repair doubler and repair filler to accomplish each window corner repair. 3. Parts Modified and Reidentified None. 4. Parts Removed and Not Replaced None. D. Parts Necessary to Change Spares None. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 30 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 31 E. Special Tooling - Price and Availability None. F. Special Tooling Necessary to do this Service Bulletin No special tools or equipment are necessary to do the change in this service bulletin. But, maintenance and overhaul tools in the manuals given in Paragraph 1.J., References, can be necessary. Examine operator tool supply to make sure all necessary tools are available. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 31 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 32 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 32 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT BLANK PAGE ### Page 33 3. ACCOMPLISHMENT INSTRUCTIONS A. GENERAL INFORMATION NOTE: 1. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for definition of the acronyms. 2. Obey all of the warnings and cautions given in the specified manual sections. 3. Unless shown differently, these dimensions and tolerances are used: – Linear dimensions are in inches – Tolerance on linear dimensions, other than rivet and bolt edge margins, is plus or minus 0.03 inch – Tolerance on rivet and bolt edge margin is plus or minus 0.05 inch – Angular tolerance is plus or minus 2 degrees – Hole dimensions for standard solid rivets and fasteners are in Structural Repair Manual (SRM) Chapter 51 – Torque Values: — Values for structural fasteners are given in 737 Structural Repair Manual, Chapter 51. — Values for airframe maintenance tasks are included in Chapter 20 of 737 Airplane Maintenance Manual (AMM). — Values for engine maintenance tasks are included in Chapter 70 of 737 Airplane Maintenance Manual (AMM). — Non-standard torque values for maintenance tasks are included in the applicable installation step. 4. Use the approved fastener and process material substitutions in accordance with SRM Chapter 51. 5. If the length of any fastener specified in this service bulletin does not meet installation standards given in SRM Chapter 51, then a fastener of the same specification, or an approved substitute, with a length which meets the installation standards given in SRM Chapter 51 may be used. In addition, washers may be installed for fastener grip length in accordance with SRM Chapter 51. Refer to SOPM 20-50-01 for alternate full threaded fasteners (screws) needed for installation in this service bulletin. 6. A Detailed Inspection is defined as: An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirrors, magnifying lenses, etc. may be necessary. Surface cleaning and elaborate procedures may be required. 7. These work instructions refer to procedures included in other Boeing documents. When the words "refer to" are used and the operator has an accepted alternative procedure, the accepted alternative procedure can be used. When the words "in accordance with" are included in the instruction, the procedure in the Boeing document must be used. 8. Refer to APPENDIX A for Window Frame Edge Margin requirements and fastener area identification. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 33 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 34 9. Refer to APPENDIX B for fuel burn and performance penalties. 10. The instructions in Paragraph 3.B., Work Instructions and the figures can include operation of tools or test equipment. Boeing Engineering Tool Drawings, the Illustrated Tool and Equipment Manual, and the Special Tool and Ground Handling Drawing Index contain data on versions of the tools or test equipment that you can use. It is permitted to use replaced tools. It is not permitted to use superseded tools. 11. If it is necessary to remove more parts for access, you can remove those parts. If you can get access without removing identified parts, it is not necessary to remove all of the identified parts. Jacking and shoring limitations must be observed. 12. Where the work instructions include installation of a kept part, a new or serviceable part with the same part number can be installed as an alternative to the kept part. 13. This service bulletin includes functional test procedures for the systems changed by this service bulletin. More functional tests can possibly be necessary in accordance with standard maintenance practices because of interruption to other airplane systems. 14. Some Boeing parts are supplied in a temporary configuration. Those parts are identified with a 'U', 'W', or 'Y' in place of the '-' (dash) in the part number. It is permitted to install parts identified with a 'U', 'W', or 'Y' as an alternative to the '-' (dash) part number. Boeing Drawing 005W0900 contains more data. 15. If shading is used, shaded areas in Figures are to separate the non-critical and non-authoritative information from the critical and authoritative information. 16. When more than one OPTION is given for a CONDITION, do only one of the OPTION numbers. When more than one ACTION is given for a CONDITION number or an OPTION number, do all of the ACTION numbers for that CONDITION number or OPTION number. 17. The compliance times for the actions in Paragraph 3.B., WORK INSTRUCTIONS are in Paragraph 1.E., Compliance. 18. The CONDITIONS, ACTIONS and OPTIONS shown apply to each side of the airplane independently. 19. Some steps in the Work Instructions are identified as Required for Compliance (RC). If this service bulletin is mandated by an Airworthiness Directive (AD), then the steps identified as RC must be done to comply with the AD. Alternative procedures for steps not identified with RC can be used if the RC steps can still be done as specified,and the airplane can be put back in a serviceable condition. An Alternative Method of Compliance (AMOC) is not necessary for deviations to steps that are not identified as RC. B. WORK INSTRUCTIONS 1. Group 1: RC - Do PART 1: WINDOW CORNER EXTERNAL SURFACE HFEC INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 908. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 34 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 35 a. CONDITION 1: NO CRACK FOUND IN THE SKIN AT ANY OF THE TWELVE FASTENER HOLE LOCATIONS COMMON TO ANY WINDOW CORNER BETWEEN STA 360 TO STA 540, OR BETWEEN STA 727 TO STA 908. (1) RC - Repeat PART 1 - WINDOW CORNER EXTERNAL SURFACE HFEC INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 908 - INSPECTION at the times given in Paragraph 1.E., Compliance. NOTE: It is optional to accomplish the Part 3 preventive modification in accordance with PART 3 - PREVENTIVE MODIFICATION. Accomplishment of the preventive modification is terminating action for the initial and repeat inspections at the modified location only. Post modification inspections are provided in PART 8. b. CONDITION 2: ANY CRACK FOUND IN THE SKIN AT ANY OF THE THREE CORNER FASTENER HOLE LOCATIONS BETWEEN STA 380 TO STA 500C+10.00 OR BETWEEN STA 727E+10.45 TO STA 897.45 AND IS WITHIN THE MAXIMUM TRIMOUT LIMITS OF PART 6 REPAIR. (1) RC - Do PART 6 - WINDOW CORNER CRACK REPAIR. c. CONDITION 3: ANY CRACK FOUND IN THE SKIN AT ANY OF THE THREE CORNER FASTENER HOLE LOCATIONS BETWEEN STA 360 TO STA 380, STA 500C+10.00 TO STA 540, STA 727 TO STA 727+10.45 OR BETWEEN STA 897.45 TO STA 908, OR ANY CRACK FOUND AT THE THREE CORNER FASTENER HOLE LOCATIONS THAT IS NOT WITHIN THE MAXIMUM TRIMOUT LIMITS. (1) RC - Contact Boeing for repair instructions and do the repair. d. CONDITION 4: ANY CRACK FOUND IN THE SKIN THAT IS NOT AT THE THREE CORNER FASTENER HOLE LOCATIONS BETWEEN STA 360 TO STA 540, AND STA 727 TO STA 908. (1) RC - Contact Boeing for repair instructions and do the repair. 2. Group 2: RC - Do PART 1: WINDOW CORNER EXTERNAL SURFACE HFEC INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 908. a. CONDITION 1: NO CRACK FOUND IN THE SKIN AT ANY OF THE TWELVE FASTENER HOLE LOCATIONS COMMON TO ANY WINDOW CORNER BETWEEN STA 360 TO STA 540, OR BETWEEN STA 727 TO STA 908. (1) RC - Repeat PART 1 - WINDOW CORNER EXTERNAL SURFACE HFEC INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 908 - INSPECTION at the times given in Paragraph 1.E., Compliance. NOTE: It is optional to accomplish the Part 3 preventive modification in accordance with PART 3 - PREVENTIVE MODIFICATION. Accomplishment of the preventive modification is terminating action for the initial and repeat inspections at the modified location only. Post modification inspections are provided in PART 8. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 35 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 36 b. CONDITION 5: ANY CRACK FOUND IN THE SKIN AT ANY OF THE TWELVE FASTENER HOLE LOCATIONS BETWEEN STA 360 TO STA 540, OR BETWEEN STA 727 TO STA 908. (1) RC - Contact Boeing for repair instructions and do the repair. PART 1 - WINDOW CORNER EXTERNAL SURFACE HFEC INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 908 1. Do the following inspections:- NOTE: If any Boeing ODA approved repair via FAA Form 8100-9 was installed to eliminate cracking that was previously found, further inspections in the window corner are not required at the repaired location. a. RC - Do an external surface HFEC inspection for cracks in the skin at the upper forward and lower aft corners of each left side window between STA 360 to STA 540 in accordance with FIGURE 1. b. RC - Do an external surface HFEC inspection for cracks in the skin at the upper forward and lower aft corners of each right side window, between STA 360 to STA 540 in accordance with FIGURE 2. c. RC - Do an external surface HFEC inspection for cracks in the skin at the lower forward and upper aft corners of each left side window between STA 727 to STA 908 in accordance with FIGURE 3. d. RC - Do an external surface HFEC inspection for cracks in the skin at the lower forward and upper aft corners of each right side window between STA 727 to STA 908 in accordance with FIGURE 4. PART 2 - ACCESS 1. To get access remove the following equipment in the areas between STA 360 to STA 540 and STA 727 to STA 908: 2. Remove the forward and aft galley and associated header panels. Refer to 737-300/400/500 AMM 25-31-11 for Galley No.1, 737-300/400/500 AMM 25-31-31 for Galley No.3, 737-300/400/500 AMM 25-31-41 for Galley No.4, 737-300/400/500 AMM 25-31-83 for Forward Header and 737-300/400/500 AMM 25-31-87 for Aft Header as accepted procedures. 3. Remove the overhead stowage bins. Refer to 737-300/400/500 AMM 25-24-31 as an accepted procedure. 4. Remove the passenger Service Units. Refer to 737-300/400/500 AMM 25-23-61 as an accepted procedure. 5. Remove the sidewall panels and insulation blankets from the passenger cabin. Refer to 737-300/400/500 AMM 25-21-46 and 737-300/400/500 AMM 25-21-39 as accepted procedures. 6. Remove the sculptured ceiling panels from the passenger cabin. Refer to 737-300/400/500 AMM 25-21-45 as an accepted procedure. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 36 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 37 7. Remove the lowered ceiling panels from the passenger cabin. Refer to 737-300/400/500 AMM 25-21-71 as an accepted procedure. 8. Remove the Equipment Cooling System (ECS) ducting. Refer to 737-300/400/500 AMM 21-23-25 as an accepted procedure. 9. Remove windows. Refer to 737-300/400/500 AMM 56-21-00 as an accepted procedure. 10. When the windows are removed, do a detailed inspection of the window frames for nicks, gouges and scratches at the locations where the window frame clips are located. a. If any nick, gouge or scratch is found that is within the allowable damage limits given in 737-300 SRM 56-20-02, 737-400 SRM 56-20-02 or 737-500 SRM 56-20-02, repair the window frame in accordance with 737-300 SRM 56-20-02, 737-400 SRM 56-20-02 or 737-500 SRM 56-20-02. b. If any nick, gouge or scratch is found that is not within the allowable damage limits given in 737-300 SRM 56-20-02, 737-400 SRM 56-20-02 or 737-500 SRM 56-20-02, replace the window frame in accordance with PART 7 - WINDOW FRAME REPLACEMENT or contact Boeing. Do not install fasteners in holes common to the repair or modification at this time. 11. Remove partitions and wind screens. Refer to 737-300/400/500 AMM 25-24-00 as accepted procedures. 12. Remove entry doorway liner and service doorway liners. Refer to 737-300/400/500 AMM 25-21-25, 737-300/400/500 AMM 25-21-31, 737-300/400/500 AMM 25-21-35 and 737-300/400/500 AMM 25-21-39 as accepted procedures. 13. Remove passenger seats. Refer to 737-300/400/500 AMM 25-22-00 as an accepted procedure. PART 3 - PREVENTIVE MODIFICATION 1. Do PART 2 - ACCESS. 2. RC - Do PART 4 - OPEN HOLE INSPECTION. a. No crack found in the skin, window frame or stringer at any of the twelve fastener hole locations between STA 360 to STA 540 or between STA 727 to STA 908. (1) Oversize hole to provide an insurance cut in accordance with Table 1 hole diameters. Maintain 3D to 6D spacing between fasteners. Maintain 1.7D minimum edge margin for holes common to production parts, except for window frames which must meet requirements of Table 3. (2) Install a new fastener in each oversized hole in accordance with Table 1. When installing Hi-lok fasteners, if the collars do not sit flush and the collar rides on the radius of the window forging, do the following: (a) Make a radius filler from 7075-T6 aluminum to match the contour of the window frame. (b) Maintain a 1D minimum edge margin. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 37 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 38 (c) Maintain a thickness no greater than 0.250 inches and no less than 0.063 inches. (d) Maintain 125Ra or better surface roughness on all machined surfaces (production and repair parts). (e) Apply chemical conversion coating, refer to SOPM 20-43-03 as an accepted procedure. Apply one coat of BMS 10-11, Type I primer, refer to SOPM 20-41-02 as an accepted procedure. (f) Make sure the radius filler does not move when the nut is installed. Table 1 - Replacement Oversize Fasteners Replacement FastenerProduction Fastener More Data Hole DiameterPart NumberTypeDiameterType (a) (b)0.263-0.266BACB30FP8A( )Hi-lok3/16 inchRivet --BACC30M( )Collar (a)0.263-0.266BACB30FP8A( )Hi-lok3/16 inchHi-lok --BACC30M( )Collar (a) (c)0.325-0.328BACB30FP10A( )Hi-lok1/4 inchRivet --BACC30M( )Collar (a)0.325-0.328BACB30FP10A( )Hi-lok1/4 inchHi-lok --BACC30M( )Collar (a) Install hi-lok wet with BMS 5-95 sealant. The titanium equivalent BACB30MY( )K( )X of the same diameter can be substituted for the cad plated stainless steel hi-lok. ( ) Use grip length as necessary for correct installation. Refer to SRM Chapter 51. (b) Install a BACR15BB8AD( )C rivet in 0.263 - 0.265 inch diameter hole if the hi-lok collar interferes with the window retaining clip. ( ) Use grip length as necessary for correct in- stallation. Refer to SRM Chapter 51. (c) Install a BACR15BB10AD( )C rivet in 0.325 - 0.327 inch diameter hole if the hi-lok collar interferes with the window retaining clip. ( ) Use grip length as necessary for correct in- stallation. Refer to SRM Chapter 51. b. Any crack found in the skin, window frame or stringer at any of the twelve fastener hole locations common to any window corner between STA 360 to STA 540 or between STA 727 to STA 908 and is within the maximum oversize hole limits of Part 5 before insurance cut. (1) Do PART 5: OVERSIZE HOLE REPAIR. NOTE: Accomplishment of Part 5 satisfies all of the requirements of the Part 3 modification and is considered equivalent to the Part 3 modification. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 38 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 39 c. Any crack found in the skin that extends beyond the maximum oversize hole limits of Part 5 before insurance cut at any of the three corner fastener hole locations between STA 380 to STA 500C+10.00 or between STA 727E+10.45 to STA 897.45 and is within the maximum trimout limit of Part 6. (1) Group 1: Do PART 6: WINDOW CORNER CRACK REPAIR. (2) Group 2: Contact Boeing for repair instructions and do the repair. d. Any crack found in the skin that extends beyond the oversize hole limits of Part 5 before insurance cut and is not at the three corner fastener hole locations between STA 380 to STA 500C+10.00 or between STA 727E+10.45 to STA 897.45. (1) Contact Boeing for repair instructions and do the repair. e. Any crack found in the skin that extends beyond the oversize hole limits of Part 5 before insurance cut at a fastener hole location between STA 360 to STA 380, STA 500C+10.00 to STA 540, STA 727 to STA 727E+10.45 or between STA 897.45 to STA 908. (1) Contact Boeing for repair instructions and do the repair. f. Any crack found in a stringer that extends beyond the oversize hole limits of Part 5 before insurance cut. (1) Contact Boeing for repair instructions and do the repair. g. Any crack found in the window frame that extends beyond the oversize hole limits of Part 5 before insurance cut. (1) Do PART 7: WINDOW FRAME REPLACEMENT. PART 4 - WINDOW CORNER OPEN HOLE INSPECTION FROM STA 360 TO STA 540 AND FROM STA 727 TO STA 908 1. RC - Do an open hole HFEC inspection for cracks in the skin, stringer and window frame, at the upper forward and lower aft corners of each left side window between STA 360 to STA 540 in accordance with FIGURE 5. NOTE: Do all the applicable steps in Part 3. 2. RC - Do an open hole HFEC inspection for cracks in the skin, stringer and window frame, at the upper forward and lower aft corners of each right side window between STA 360 to STA 540 in accordance with FIGURE 6. NOTE: Do all the applicable steps in Part 3. 3. RC - Do an open hole HFEC inspection for cracks in the skin, stringer and window frame, at the lower forward and upper aft corners of each left side window between STA 727 to STA 908 in accordance with FIGURE 7. NOTE: Do all the applicable steps in Part 3. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 39 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 40 4. RC - Do an open hole HFEC inspection for cracks in the skin, stringer and window frame, at the lower forward and upper aft corners of each right side window between STA 727 to STA 908 in accordance with FIGURE 8. NOTE: Do all the applicable steps in Part 3. PART 5 - OVERSIZE HOLE REPAIR 1. RC - Oversize to the maximum oversize limit before insurance cut given in Table 2 and accomplish an open hole inspection in accordance with 737 NDT Manual Part 6, 51-00-00, Procedure 16, using a 0.02 inch notch calibration. Table 2 - Oversize hole diameters Maximum Oversize before in- surance cut (a) Original Fastener 0.2233/16 Rivet 0.2233/16 Hi Lok 0.2851/4 Rivet 0.2851/4 Hi-Lok (a) Inspect for cracks in accordance with 737 NDT Manual Part 6, 51-00-00, Procedure 16 using a 0.02 inch notch calibration before oversizing to the final diameter to make the required insurance cut. a. Crack indications are completely removed. (1) Install a new fastener in each oversized hole in accordance with Table 1. Refer to Table 3 for edge margin requirements for the window frames. When installing Hi-lok fasteners, if the collars do not sit flush and the collar rides on the radius of the window forging, do the following: (a) Make a radius filler from 7075-T6 aluminum to match the contour of the window frame. (b) Maintain a 1D minimum edge margin. (c) Maintain a thickness no greater than 0.250 inches and no less than 0.063 inches. (d) Maintain 125Ra or better surface roughness on all machined surfaces (production and repair parts). (e) Apply chemical conversion coating, refer to SOPM 20-43-03 as an accepted procedure. Apply one coat of BMS 10-11, Type I primer, refer to SOPM 20-41-02 as an accepted procedure. (f) Make sure the radius filler does not move when the nut is installed. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 40 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 41 NOTE: It is acceptable to determine the edge margins of the fasteners common to the window forging prior to enlarging the holes to the final oversize diameter. Make sure the edge margin, as defined in Table 3 is based on the final hole diameter. Table 3 - Edge margin requirements for fasteners common to the window frame NotesEdge Margin (d)Fastener Group (e) (a)Greater than or equal to 1.5DA (b)Greater than or equal to 1.2D and less than 1.5DA (c)Less than 1.2DA (a)Greater than or equal to 1.5DB (b)Greater than or equal to 1.35D and less than 1.5DB (c)Less than 1.35DB (a) The repair or preventive modification is considered structurally satisfactory without special inspections beyond normal maintenance. (b) The repair or preventive modification is structurally satisfactory with continued inspec- tions. Post modification and post repair inspections are provided in Paragraph 1.E., Compliance, Table 4 and Table 5. (c) Remove and replace the window frame with the original frame part number 65-45785- 521 or 65-45785-9. Part number 65-45785U9 is an acceptable one way forward re- placement. Make sure new window frame meets edge margin requirements above. (d) Edge margin is defined as the distance between the center of the hole and the edge of the part. D is defined as the final fastener hole diameter of the oversized hole. (e) Refer to APPENDIX A for fastener group definition. b. Any crack found in the skin that extends beyond the maximum oversize hole limits of Part 5 before insurance cut at any of the three corner fastener hole locations between STA 380 to STA 500C+10.00 or between STA 727E+10.45 to STA 897.45 and is within the maximum trimout limit of Part 6. (1) Group 1: Do PART 6: WINDOW CORNER CRACK REPAIR. (2) Group 2: Contact Boeing for repair instructions and do the repair. c. Any crack found in the skin that extends beyond the oversize hole limits of Part 5 before insurance cut and is not at the three corner fastener hole locations between STA 380 to STA 500C+10.00 or between STA 727E+10.45 to STA 897.45. (1) Contact Boeing for repair instructions and do the repair. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 41 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 42 d. Any crack found in the skin that extends beyond the oversize hole limits of Part 5 before insurance cut at a fastener hole location between STA 360 to STA 380, STA 500C+10.00 to STA 540, STA 727 to STA 727E+10.45 or between STA 897.45 to STA 908. (1) Contact Boeing for repair instructions and do the repair. e. Any crack found in a stringer that extends beyond the oversize hole limits of Part 5 before insurance cut. (1) Contact Boeing for repair instructions and do the repair. f. Any crack found in the window frame that extends beyond the oversize hole limits of Part 5 before insurance cut. (1) Do PART 7: WINDOW FRAME REPLACEMENT. Group 1: PART 6 - WINDOW CORNER CRACK REPAIR 1. Do PART 2 - ACCESS. 2. RC - Do the repair in accordance with the applicable figure given in Table 4 below. Table 4 - Crack Location/Repair Figure Repair in ac- cordance with: Window Corner Crack Location FIGURE 9Left side - Upper Forward corner - STA 380 to STA 500C+10.00 FIGURE 10Right side - Upper Forward corner - STA 380 to STA 500C+10.00 FIGURE 11Left side - Lower Aft corner - STA 380 to STA 500C+10.00 FIGURE 12Right side - Lower Aft corner - STA 380 to STA 500C+10.00 FIGURE 13Left side - Adjacent Upper Forward and Lower Aft corners - STA 380 to STA 500C+10.00 FIGURE 14Right side - Adjacent Upper Forward and Lower Aft corners - STA 380 to STA 500C+10.00 FIGURE 15Left side - Upper Aft corner - STA 727E+10.45 to STA 897.45 FIGURE 16Right side - Upper Aft corner - STA 727E+10.45 to STA 897.45 FIGURE 17Left side - Lower Forward corner - STA 727E+10.45 to STA 897.45 FIGURE 18Right side - Lower Forward corner - STA 727E+10.45 to STA 897.45 FIGURE 19Left side - Adjacent Upper Aft and Lower Aft corners - STA 727E+10.45 to STA 897.45 FIGURE 20Right side - Adjacent Upper Aft and Lower Aft corners - STA 727E+10.45 to STA 897.45 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 42 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 43 a. Any crack found outside the limits of the trim or corrosion found during accomplishment of the repair. (1) Contact Boeing for repair instructions and do the repair. 3. RC - Apply BMS 3-23 corrosion inhibiting compound to the internal surfaces of the repair area after the repair has been installed and the BMS 5-95 sealant has cured. Refer to SOPM 20-41-05 as an accepted procedure. 4. RC - Apply the finish to the repair. Refer to 737-300/400/500 AMM 51-21-00 as an accepted procedure. PART 7 - WINDOW FRAME REPLACEMENT 1. RC - Replace the window frame with the original frame part number 65-45785-521 or 65-45785-9. Part number 65-45785U9 is also an acceptable replacement. It is identical to 65-45785-9 except all pilot holes are omitted. Make sure new window frame meets edge margin requirements as shown in Table 3 above. a. When installing fasteners, if the collars do not sit flush and the collar rides on the radius of the window forging, do the following: (1) Make a radius filler from 7075-T6 aluminum to match the contour of the window frame. (2) Maintain a 1D minimum edge margin. (3) Maintain a thickness no greater than 0.250 inches and no less than 0.063 inches. (4) Maintain 125Ra or better surface roughness on all machined surfaces (production and repair parts). (5) Apply chemical conversion coating, refer to SOPM 20-43-03 as an accepted procedure. Apply one coat of BMS 10-11, Type I primer, refer to SOPM 20-41-02 as accepted procedure. (6) Make sure the radius filler does not move when the nut is installed. b. Install a replacement oversize fastener at locations inspected in Part 1 in accordance with Table 5 below. Table 5 - Replacement Oversize Fasteners Replacement FastenerProduction Fastener More Data Hole DiameterPart NumberTypeDiameterType (a) (b)(0.263-0.266)BACB30FP8A( )Hi-lok3/16 inchRivet --BACC30M( )Collar Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 43 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 44 Table 5 - Replacement Oversize Fasteners Replacement FastenerProduction Fastener More Data Hole DiameterPart NumberTypeDiameterType (a)(0.263-0.266)BACB30FP8A( )Hi-lok3/16 inchHi-lok --BACC30M( )Collar (a) (c)(0.325-0.328)BACB30FP10A( )Hi-lok1/4 inchRivet --BACC30M( )Collar (a)(0.325-0.328)BACB30FP10A( )Hi-lok1/4 inchHi-lok --BACC30M( )Collar (a) Install hi-lok wet with BMS 5-95 sealant. The titanium equivalent BACB30MY( )K( )X of the same diameter can be substituted for the cad plated stainless steel hi-lok. ( ) Use grip length as necessary for correct installation. Refer to SRM Chapter 51. (b) Install a BACR15BB8AD( )C rivet in 0.263 - 0.265 inch diameter hole if the hi-lok collar interferes with the window retaining clip. ( ) Use grip length as necessary for correct in- stallation. Refer to SRM Chapter 51 (c) Install a BACR15BB10AD( )C rivet in 0.325 - 0.327 inch diameter hole if the hi-lok collar interferes with the window retaining clip. ( ) Use grip length as necessary for correct in- stallation. Refer to SRM Chapter 51 PART 8 - POST REPAIR/POST MODIFICATION INSPECTIONS 1. Do PART 2 - ACCESS NOTE: Internal access is only required at locations where the step 5 or step 6 internal inspections are necessary. 2. For window corner locations that have done the preventive modification or oversize hole repair (without an external doubler) do the inspections that follow. If any crack is found, contact Boeing for repair instructions and do the repair. a. Do an external surface HFEC inspection for cracks at left side upper forward and lower aft window corners between STA 360 to STA 540 in accordance with FIGURE 33. b. Do an external surface HFEC inspection for cracks at right side upper forward and lower aft window corners between STA 360 to STA 540 in accordance with FIGURE 34. c. Do an external surface HFEC inspection for cracks at left side upper aft and lower forward window corners between STA 727 to STA 908 in accordance with FIGURE 35. d. Do an external surface HFEC inspection for cracks at right side upper aft and lower forward window corners between STA 727 to STA 908 in accordance with FIGURE 36. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 44 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 45 3. Group 1: For window corner locations between STA 380 and STA 500C+10 that have installed the Part 6, external doubler repair, do the inspections that follow. If any crack is found, contact Boeing for repair instructions and do the repair. a. Do external LFEC and HFEC inspections for cracks in the skin and doubler at the left side upper forward window corner repair in accordance with FIGURE 21. b. Do external LFEC and HFEC inspections for cracks in the skin and doubler at the right side upper forward window corner repair in accordance with FIGURE 22. c. Do external LFEC and HFEC inspections for cracks in the skin and doubler at the left side lower aft window corner repair in accordance with FIGURE 23. d. Do external LFEC and HFEC inspections for cracks in the skin and doubler at the right side lower aft window corner repair in accordance with FIGURE 24. e. Do external LFEC and HFEC inspections for cracks in the skin and doubler at the left side upper forward and lower aft corners in accordance with FIGURE 25. f. Do external LFEC and HFEC inspections for cracks in the skin and doubler at the right side upper forward and lower aft window corner repair in accordance with FIGURE 26. 4. Group 1: For window corner locations between STA 727E+10.45 and STA 897.45 that have installed the Part 6, external doubler repair, do the inspections that follow. If any crack is found, contact Boeing for repair instructions and do the repair. a. Do external LFEC and HFEC inspections for cracks in the skin and doubler at the left side upper aft window corner repair in accordance with FIGURE 27. b. Do external LFEC and HFEC inspections for cracks in the skin and doubler at the right side upper aft window corner repair in accordance with FIGURE 28. c. Do external LFEC and HFEC inspections for cracks in the skin and doubler at the left side lower forward window corner repair in accordance with FIGURE 29. d. Do external LFEC and HFEC inspections for cracks in the skin and doubler at the right side lower forward window corner repair in accordance with FIGURE 30. e. Do external LFEC and HFEC inspections for cracks in the skin and doubler at the left side upper aft and lower forward corners in accordance with FIGURE 31. f. Do external LFEC and HFEC inspections for cracks in the skin and doubler at the right side upper aft and lower forward window corner repair in accordance with FIGURE 32. 5. RC - For window frames where the edge margin is greater than or equal to 1.2D and less than 1.5D at a Group A fastener location as a result of accomplishing the preventive modification (Part 3) or oversize hole repair (Part 5) or external doubler repair (Part 6), do an internal detailed inspection for cracks in the window forging all around the bolts and collars. In particular look for cracks at the edge of the frame common to the short edge margin. The use of a 10X magnifying glass is required for the edge inspection. If any crack is found, contact Boeing for repair instructions and do the repair. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 45 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 46 NOTE: Edge margin is defined as the distance between the center of the hole and the edge of the part. D is defined as the final fastener hole diameter of the oversized hole. NOTE: Refer to APPENDIX A for fastener group definition. 6. RC - For window frames where the edge margin is greater than or equal to 1.35D and less than 1.5D at a Group B fastener location as a result of accomplishing the preventive modification (Part 3) or oversize hole repair (Part 5) or external doubler repair (Part 6), do an internal detailed inspection for cracks in the window forging all around the bolts and collars. In particular look for cracks at the edge of the frame common to the short edge margin. The use of a 10X magnifying glass is required for the edge inspection. If any crack is found, contact Boeing for repair instructions and do the repair. NOTE: Edge margin is defined as the distance between the center of the hole and the edge of the part. D is defined as the final fastener hole diameter of the oversized hole. NOTE: Refer to APPENDIX A for fastener group definition. 7. Do PART 9 - CLOSE ACCESS AND TEST. PART 9 - CLOSE ACCESS AND TEST 1. Install and test the forward and aft galley and associated header panels. Refer to 737-300/400/500 AMM 25-31-11 for Galley No.1, 737-300/400/500 AMM 25-31-31 for Galley No.3, 737-300/400/500 AMM 25-31-41 for Galley No.4, 737-300/400/500 AMM 25-31-83 for Forward Header and 737-300/400/500 AMM 25-31-87 for Aft Header as accepted procedures. 2. Install the overhead stowage bins. Refer to 737-300/400/500 AMM 25-24-31 as an accepted procedure. 3. Install and test the passenger Service Units. Refer to 737-300/400/500 AMM 25-23-61 as an accepted procedure. 4. Install the sidewall panels and insulations blankets to the passenger cabin. Refer to 737-300/400/500 AMM 25-21-46 and 737-300/400/500 AMM 25-21-39 as accepted procedures. NOTE: Prior to installation of the insulation blankets apply BMS 3-23 Type II to the inside of the newly installed skins in accordance with SOPM 20-41-05. NOTE: If necessary refer to SOPM 20-20-11 as an accepted procedure for instructions to Repair Insulation Blankets. 5. Install the sculptured ceiling panels to the passenger cabin. Refer to 737-300/400/500 AMM 25-21-45 as an accepted procedure. 6. Install the lowered ceiling panels to the passenger cabin. Refer to 737-300/400/500 AMM 25-21-71 as an accepted procedure. 7. Install and test the ECS ducting. Refer to 737-300/400/500 AMM 21-23-25 as an accepted procedure. 8. Install windows. Refer to 737-300/400/500 AMM 56-21-00 as an accepted procedure. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 46 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 47 9. Install partitions and wind screens. Refer to 737-300/400/500 AMM 25-24-15 as accepted procedures. 10. Install entry door and service door liners. Refer to 737-300/400/500 AMM 25-21-25, 737-300/400/500 AMM 25-21-31, 737-300/400/500 AMM 25-21-35 and 737-300/400/500 AMM 25-21-39 as accepted procedures. 11. Install and retest passenger seats. Refer to 737-300/400/500 AMM 25-22-00 as an accepted procedure. 12. Do Cabin Pressurization Leakage Check. Refer to 737-300/400/500 AMM 05-51-91 as an accepted procedure. 13. Operationally or functionally test any disturbed systems. Refer to 737-300/400/500 AMM or operator approved equivalent procedure. 14. Return airplane to a serviceable condition. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 47 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 48 (OCR) BOEING SERVICE BULLETIN 737-53A1328 ALERT ALERT STA 540 STA 360 S-10 THREE CORNER (2 FASTENERS THREE CORNER FASTENERS S4-======= FWD STA 360-540 (TYPICAL) FIGURE 1: STA 360 TO STA 540 LEFT SIDE - UPPER FORWARD AND LOWER AFT WINDOW CORNER - EXTERNAL SURFACE INSPECTION (SHEET 1 OF 2) Original Issue: July 22, 2014 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished 737-53A1328 Work - See page 1 for details. 48 of 157 ### Page 49 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)18-SkinInspect1 (b)6-SkinInspect2 (a) Do an external surface HFEC inspection for cracks in the skin around the fastener locations in accordance with 737 NDT Manual Part 6, 51-00-00, Procedure 4 or 23. (b) Do an external surface HFEC inspection of the three corner fasteners for cracks in the skin around the fastener locations in accordance with 737 NDT Manual Part 6, 51-00-00, Procedure 4 or 23. FIGURE 1: STA 360 TO STA 540 LEFT SIDE - UPPER FORWARD AND LOWER AFT WINDOW CORNER - EXTERNAL SURFACE INSPECTION (SHEET 2 OF 2) Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 49 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 50 (OCR) BOEING SERVICE BULLETIN 737-53A1328 ALERT ALERT STA 540 STA 360 S-10 THREE 2 CORNER FASTENERS THREE CORNER FASTENERS FWD STA 360-540 2271518 (TYPICAL) FIGURE 2: STA 360 TO STA 540 RIGHT SIDE - UPPER FORWARD AND LOWER AFT WINDOW CORNER - EXTERNAL SURFACE INSPECTION (SHEET 1 OF 2) Original Issue: July 22, 2014 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished 737-53A1328 Work - See page 1 for details. 50 of 157 ### 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 (a)18-SkinInspect1 (b)6-SkinInspect2 (a) Do an external surface HFEC inspection for cracks in the skin around the fastener locations in accordance with 737 NDT Manual Part 6, 51-00-00, Procedure 4 or 23. (b) Do an external surface HFEC inspection of the three corner fasteners for cracks in the skin around the fastener locations in accordance with 737 NDT Manual Part 6, 51-00-00, Procedure 4 or 23. FIGURE 2: STA 360 TO STA 540 RIGHT SIDE - UPPER FORWARD AND LOWER AFT WINDOW CORNER - EXTERNAL SURFACE INSPECTION (SHEET 2 OF 2) Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 51 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 52 (OCR) BOEING SERVICE BULLETIN 737-53A1328 ALERT ALERT STA STA 908 727 S-10 THREE CORNER FASTENERS THREE CORNER 2 FASTENERS S-14 - FWD STA 727-908 (TYPICAL) FIGURE 3: STA 727 TO STA 908 LEFT SIDE - LOWER FORWARD AND UPPER AFT WINDOW CORNER - EXTERNAL SURFACE INSPECTION (SHEET 1 OF 2) Original Issue: July 22, 2014 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished 737-53A1328 Work - See page 1 for details. 52 of 157 ### 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)18-SkinInspect1 (b)6-SkinInspect2 (a) Do an external surface HFEC inspection for cracks in the skin around the fastener locations in accordance with 737 NDT Manual Part 6, 51-00-00, Procedure 4 or 23. (b) Do an external surface HFEC inspection of the three corner fasteners for cracks in the skin around the fastener locations in accordance with 737 NDT Manual Part 6, 51-00-00, Procedure 4 or 23. FIGURE 3: STA 727 TO STA 908 LEFT SIDE - LOWER FORWARD AND UPPER AFT WINDOW CORNER - EXTERNAL SURFACE INSPECTION (SHEET 2 OF 2) Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 53 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 54 (OCR) BOEING SERVICE BULLETIN 737-53A1328 ALERT ALERT STA 908 S-10 THREE CORNER FASTENERS THREE 2) CORNER FASTENERS EZEE FWD STA 727-908 2271514 (TYPICAL) FIGURE 4: STA 727 TO STA 908 RIGHT SIDE - LOWER FORWARD AND UPPER AFT WINDOW CORNER - EXTERNAL SURFACE INSPECTION (SHEET 1 OF 2) Original Issue: July 22, 2014 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished 737-53A1328 Work - See page 1 for details. 54 of 157 ### 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)18-SkinInspect1 (b)6-SkinInspect2 (a) Do an external surface HFEC inspection for cracks in the skin around the fastener locations in accordance with 737 NDT Manual Part 6, 51-00-00, Procedure 4 or 23. (b) Do an external surface HFEC inspection of the three corner fasteners for cracks in the skin around the fastener locations in accordance with 737 NDT Manual Part 6, 51-00-00, Procedure 4 or 23. FIGURE 4: STA 727 TO STA 908 RIGHT SIDE - LOWER FORWARD AND UPPER AFT WINDOW CORNER - EXTERNAL SURFACE INSPECTION (SHEET 2 OF 2) Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 55 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 56 (OCR) BOEING SERVICE BULLETIN 737-53A1328 ALERT ALERT STA 540 STA 360 S-10 S-14 - FWD STA 360-540 (TYPICAL) FIGURE 5: STA 360 TO STA 540 LEFT SIDE - UPPER FORWARD AND LOWER AFT WINDOW CORNERS - OPEN HOLE INSPECTION (SHEET 1 OF 2) Original Issue: July 22, 2014 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished 737-53A1328 Work - See page 1 for details. 56 of 157 ### Page 57 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 -24-FastenersRemove1 (b) (c) (d) (e)24-HolesReam2 Do an HFEC inspection for cracks in the upper forward and lower aft window corners in accordance with 737 NDT Manual Part 6, 51-00-00, Procedure 16, using a 0.03 inch notch calibration. (a) 24-HolesInspect3 (a) If a crack is found but it is unclear which structural member is cracked, remove the window frame before the hole is oversized and inspected. (b) For Group A fastener holes, accomplish a clean up ream to a maximum hole diameter of 0.203 in ac- cordance with 737-300 SRM 51-40-05, 737-400 SRM 51-40-05, 737-500 SRM 51-40-05. (c) For Group B fastener holes, accomplish a clean up ream to a maximum hole diameter of 0.261 in ac- cordance with 737-300 SRM 51-40-05, 737-400 SRM 51-40-05, 737-500 SRM 51-40-05. (d) Refer to APPENDIX A for fastener area identification. (e) Refer to Paragraph 3.B., Work Instructions, Table 2 for edge margin requirements. FIGURE 5: STA 360 TO STA 540 LEFT SIDE - UPPER FORWARD AND LOWER AFT WINDOW CORNERS - OPEN HOLE INSPECTION (SHEET 2 OF 2) Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 57 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 58 (OCR) BOEING SERVICE BULLETIN 737-53A1328 ALERT ALERT STA 540 STA 360 S-10 377700# - S-14 FWD STA 360-540 2271510 (TYPICAL) FIGURE 6: STA 360 TO STA 540 RIGHT SIDE - UPPER FORWARD AND LOWER AFT WINDOW CORNERS - OPEN HOLE INSPECTION (SHEET 1 OF 2) Original Issue: July 22, 2014 PROPRIETARY - Copyright © Unpublished Export Controlled ECCN: 9E991 - BOEING 737-53A1328 Work - See page 1 for details. 58 of 157 ### 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 -24-FastenersRemove1 (b) (c) (d) (e)24-HolesReam2 Do an HFEC inspection for cracks in the upper forward and lower aft window corners in accordance with 737 NDT Manual Part 6, 51-00-00, Procedure 16, using a 0.03 inch notch calibration. (a) 24-HolesInspect3 (a) If a crack is found but it is unclear which structural member is cracked, remove the window frame before the hole is oversized and inspected. (b) For Group A fastener holes, accomplish a clean up ream to a maximum hole diameter of 0.203 in ac- cordance with 737-300 SRM 51-40-05, 737-400 SRM 51-40-05, 737-500 SRM 51-40-05. (c) For Group B fastener holes, accomplish a clean up ream to a maximum hole diameter of 0.261 in ac- cordance with 737-300 SRM 51-40-05, 737-400 SRM 51-40-05, 737-500 SRM 51-40-05. (d) Refer to APPENDIX A for fastener area identification (e) Refer to Paragraph 3.B., Work Instructions, Table 3 for edge margin requirements. FIGURE 6: STA 360 TO STA 540 RIGHT SIDE - UPPER FORWARD AND LOWER AFT WINDOW CORNERS - OPEN HOLE INSPECTION (SHEET 2 OF 2) Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 22, 2014 737-53A1328 59 of 157 BOEING SERVICE BULLETIN 737-53A1328 ALERTALERT ### Page 60 (OCR) BOEING SERVICE BULLETIN 737-53A1328 ALERT ALERT STA STA 908 727 S-10 S-14 - FWD STA 727-908 2220212 (TYPICAL) FIGURE 7: STA 727 TO STA 908 LEFT SIDE - LOWER FORWARD AND UPPER AFT WINDOW CORNERS - OPEN HOLE INSPECTION (SHEET 1 OF 2) Original Issue: July 22, 2014 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished 737-53A1328 Work - See page 1 for details. 60 of 157 The text continues at https://openairdocs.org/service-documents/boeing/737-53a1328/file/f5ebc065a682.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.