# Boeing Alert Service Bulletin 737-28A1273: Revision 1 - Rights: © The Boeing Company. Filed by the FAA in regulations.gov docket FAA-2017-0900; AD 2018-04-12 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. - Document: [Boeing Alert Service Bulletin 737-28A1273](https://openairdocs.org/service-documents/boeing/737-28a1273.md) - Title as filed: SB-737-28A1273-Rev01 - Pages: 234 - PDF: https://openairdocs.org/files/sha256/8b/f6/8bf6ca38082cd709cc49e22ad2c119e36c51d1216486db986665ec5f0e8aa22d - Page: https://openairdocs.org/service-documents/boeing/737-28a1273/file/8bf6ca38082c ## 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: 737-28A1273 Original Issue: December 23, 2014 Revision 1: March 14, 2017 ATA System: 2822 SUBJECT: FUEL - Engine Fuel Feed System - Wing and Center Tank Fuel Boost Pump Wire Bundle Replacement and Convoluted Liner Installation 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 Unpublished Work.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: December 23, 2014 737-28A1273Revision 1: March 14, 2017 1 of 234 2.0 ### Page 2 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 2 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT BLANK PAGE ### Page 3 Table of Contents Revision Transmittal Sheet ............................................ 7 S u m m a r y ..................................................... 1 1 1. PLANNING INFORMATION ........................................ 1 7 A . E f f e c t i v i t y ............................................... 1 7 1. Airplanes ............................................ 1 7 2 . S p a r e s A f f e c t e d ........................................ 2 9 B. Concurrent Requirements ...................................... 2 9 C. Reason ................................................ 3 0 D. Description .............................................. 3 1 E. Compliance .............................................. 3 2 F . A p p r o v a l ............................................... 3 2 G. Manpower .............................................. 3 3 H. Weight and Balance Changes .................................... 3 6 I. Electrical Load Data ......................................... 3 7 J . R e f e r e n c e s .............................................. 3 7 1. Existing Data: ......................................... 3 7 2. Data Supplied with this Service Bulletin: ........................... 3 8 3. Installation Drawings Used in the Preparation of this Service Bulletin: ........... 3 8 K. Publications Affected ........................................ 3 8 L. Interchangeability and Intermixability of Parts ........................... 3 9 M. Software Accomplishment Summary ................................ 3 9 2. MATERIAL INFORMATION ........................................ 4 1 A. Material - Price and Availability ................................... 4 1 B. Industry Support Information .................................... 4 3 C. Parts Necessary for Each Airplane ................................. 4 3 1 . K i t s / P a r t s ............................................ 4 3 2. Parts and Materials Supplied by the Operator ........................ 5 3 3. Parts Modified and Reidentified ................................ 5 3 4. Parts Removed and Not Replaced .............................. 5 3 D. Parts Necessary to Change Spares ................................. 5 4 E. Special Tooling - Price and Availability ............................... 5 4 F. Special Tooling Necessary to do this Service Bulletin ....................... 5 4 3. ACCOMPLISHMENT INSTRUCTIONS .................................. 5 5 A. GENERAL INFORMATION ..................................... 5 5 B. WORK INSTRUCTIONS ....................................... 5 7 FIGURE 1: STATION 520 LEFT GROUND BRACKET - INSTALLATION [Group 1] .......... 7 9 FIGURE 2: STATION 520 LEFT GROUND BRACKET - INSTALLATION [Group 2] .......... 8 2 FIGURE 3: STATION 520 RIGHT GROUND BRACKET - INSTALLATION [Group 1] .......... 8 5 FIGURE 4: STATION 520 RIGHT GROUND BRACKET - INSTALLATION [Group 2] .......... 8 8 FIGURE 5: LEFT WING - NO. 1 TANK AFT FUEL BOOST PUMP WIRE BUNDLE W512 AND LEFT CENTER TANK FUEL BOOST PUMP WIRE BUNDLE W514 - REMOVAL [Group 1-2] ....... 9 1 FIGURE 6: LEFT WING - NO. 1 TANK AFT FUEL BOOST PUMP WIRE BUNDLE W512 - REMOVAL [Group 1 - 2 ] ............................................... 9 4 FIGURE 7: LEFT WING - LEFT CENTER TANK FUEL BOOST PUMP WIRE BUNDLE W514 - REMOVAL [Group 1-2] ........................................... 9 5 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 3 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 4 FIGURE 8: LEFT WING - NO. 1 TANK AFT FUEL TANK CONDUIT - REPLACEMENT [Group 1] . . . 96 FIGURE 9: LEFT WING - NO. 1 TANK AFT FUEL TANK CONDUIT - REPLACEMENT [Group 2] . . . 99 FIGURE 10: LEFT WING - LEFT CENTER TANK FUEL TANK CONDUIT - REPLACEMENT [Group 1] . 102 FIGURE 11: LEFT WING - LEFT CENTER TANK FUEL TANK CONDUIT - REPLACEMENT [Group 2] . 105 FIGURE 12: LEFT WING WIRE BUNDLE W512 AND WIRE BUNDLE W514 - ROUTING [Group 1-2] . 108 FIGURE 13: NO. 1 TANK AFT FUEL BOOST PUMP WIRE BUNDLE W512 - REMOVAL OR STOWAGE [Group 1-2] .......................................... 1 1 1 FIGURE 14: LEFT CENTER TANK FUEL BOOST PUMP WIRE BUNDLE W514 - REMOVAL OR STOWAGE [Group 1-2] .......................................... 1 1 5 FIGURE 15: LEFT WING CONVOLUTED LINERS, WIRE BUNDLE W512, AND WIRE BUNDLE W514 - INSTALLATION [Group 1-2] ................................. 1 1 9 FIGURE 16: LEFT WING WIRE BUNDLE W512 AND WIRE BUNDLE W514 - ROUTING [Group 1-2] . 127 FIGURE 17: LEFT WING - NO. 1 TANK AFT FUEL BOOST PUMP - WIRING CHANGE [Group 1-2] . 132 FIGURE 18: LEFT WING - NO. 1 TANK AFT FUEL BOOST PUMP WIRE BUNDLE W512 - WIRING CHANGE [Group 1-2] .......................................... 1 3 6 FIGURE 19: LEFT WING - LEFT CENTER TANK FUEL BOOST PUMP - WIRING CHANGE [Group 1-2] ................................................. 1 4 2 FIGURE 20: LEFT WING - LEFT CENTER TANK FUEL BOOST PUMP WIRE BUNDLE W514 - WIRING CHANGE [Group 1-2] ..................................... 1 4 6 FIGURE 21: STATION 520 LEFT GROUND STUD ASSEMBLY - WIRE BUNDLE W512 AND WIRE BUNDLE W514 [Group 1] ........................................ 1 5 2 FIGURE 22: STATION 520 LEFT GROUND STUD ASSEMBLY - WIRE BUNDLE W512 AND WIRE BUNDLE W514 [Group 2] ........................................ 1 5 5 FIGURE 23: RIGHT WING - RIGHT CENTER TANK FUEL BOOST PUMP WIRE BUNDLE W516 AND NO. 2 TANK AFT FUEL BOOST PUMP WIRE BUNDLE W520 - REMOVAL [Group 1-2] . . . 158 FIGURE 24: RIGHT CENTER TANK FUEL BOOST PUMP WIRE BUNDLE W516 - REMOVAL [Group 1-2] ................................................. 1 6 1 FIGURE 25: NO. 2 TANK AFT FUEL BOOST PUMP WIRE BUNDLE W520 - REMOVAL [Group 1-2] . 162 FIGURE 26: RIGHT WING - RIGHT CENTER TANK FUEL TANK CONDUIT - REPLACEMENT [Group 1] ................................................. 1 6 3 FIGURE 27: RIGHT WING - RIGHT CENTER TANK FUEL TANK CONDUIT - REPLACEMENT [Group 2] ................................................. 1 6 6 FIGURE 28: RIGHT WING - NO. 2 TANK AFT FUEL TANK CONDUIT - REPLACEMENT [Group 1] . 169 FIGURE 29: RIGHT WING - NO. 2 TANK AFT FUEL TANK CONDUIT - REPLACEMENT [Group 2] . 172 FIGURE 30: RIGHT WING WIRE BUNDLE W516 AND WIRE BUNDLE W520 - ROUTING [Group 1] . 175 FIGURE 31: RIGHT WING WIRE BUNDLE W516 AND WIRE BUNDLE W520 - ROUTING [Group 2] . 178 FIGURE 32: RIGHT CENTER TANK FUEL BOOST PUMP WIRE BUNDLE W516 - REMOVAL OR STOWAGE [Group 1-2] .......................................... 1 8 1 FIGURE 33: NO. 2 TANK AFT FUEL BOOST PUMP WIRE BUNDLE W520 - REMOVAL OR STOWAGE [Group 1-2] .......................................... 1 8 5 FIGURE 34: RIGHT WING CONVOLUTED LINERS, WIRE BUNDLE W516, AND WIRE BUNDLE W520 - INSTALLATION [Group 1-2] ................................. 1 8 9 FIGURE 35: RIGHT WING WIRE BUNDLE W516 AND WIRE BUNDLE W520 - ROUTING [Group 1] . 197 FIGURE 36: RIGHT WING WIRE BUNDLE W516 AND WIRE BUNDLE W520 - ROUTING [Group 2] . 202 FIGURE 37: RIGHT WING - RIGHT CENTER TANK FUEL BOOST PUMP - WIRING CHANGE [Group 1-2] ................................................. 2 0 7 FIGURE 38: RIGHT WING - RIGHT CENTER TANK FUEL BOOST PUMP WIRE BUNDLE W516 - WIRING CHANGE [Group 1-2] ..................................... 2 1 1 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 4 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 5 FIGURE 39: RIGHT WING - NO. 2 TANK AFT FUEL BOOST PUMP - WIRING CHANGE [Group 1-2] . 217 FIGURE 40: RIGHT WING - NO. 2 TANK AFT FUEL BOOST PUMP WIRE BUNDLE W520 - WIRING CHANGE [Group 1-2] ..................................... 2 2 1 FIGURE 41: STATION 520 RIGHT GROUND STUD ASSEMBLY - WIRE BUNDLE W516 AND WIRE BUNDLE W520 [Group 1] ........................................ 2 2 7 FIGURE 42: STATION 520 RIGHT GROUND STUD ASSEMBLY - WIRE BUNDLE W516 AND WIRE BUNDLE W520 [Group 2] ........................................ 2 3 0 APPENDIX A: SHIELDED WIRE INSTALLATION - GENERAL SCOPE OF WORK [Group 1-2] ..... 2 3 3 APPENDIX B: PART DEMAND INTENT ................................... 2 3 4 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 5 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 6 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 6 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT BLANK PAGE ### Page 7 Commercial Airplanes 737 Service Bulletin ALERT Revision Transmittal SheetNumber: 737-28A1273Original Issue: December 23, 2014 Revision 1: March 14, 2017 ATA System: 2822 SUBJECT: FUEL - Engine Fuel Feed System - Wing and Center Tank Fuel Boost Pump Wire Bundle Replacement and Convoluted Liner Installation This revision includes all pages of the service bulletin. COMPLIANCE INFORMATION RELATED TO THIS REVISION Effects of this Revision on airplanes on which the Original Issue was previously done: None. REASON FOR REVISION This revision is sent to incorporate changes found during two validations of this service bulletin. This revision also deletes two figures that remove the fuel boost pumps, because removal of the fuel boost pumps is not necessary. Subsequent Figures are renumbered accordingly. These sections were changed: 1. Summary, Concurrent Requirements - Added statement. 2. Summary, Background - Added validation statement. Added Limit of Validity (LOV) statement for Group 3. 3. Summary, Action - Revised to match Accomplishment Instructions. Added LOV statement for Group 3. 4. Summary, Compliance and Paragraph 1.E., Compliance - Revised statement. Added LOV statement for Group 3. 5. Paragraph 1.B., Concurrent Requirements - Added table. 6. Paragraph 1.C., Reason - Added revision information. Added LOV statement for Group 3. 7. Paragraph 1.D., Description - Revised to match Accomplishment Instructions. Added LOV statement for Group 3. 8. Paragraph 1.F., Approval - Revised statement. 9. Paragraph 1.G., Manpower - Revised estimate. Added LOV statement for Group 3. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 7 of 234 ### Page 8 10. Paragraph 1.H., Weight and Balance Changes - Revised data. 11. Paragraph 1.J., References - Updated the reference list. 12. Paragraph 1.K., Publications Affected - Revised data. 13. Paragraph 2.A., Material - Price - and Availability - Revised data. Added LOV statement for Group 3. 14. Paragraph 2.C., Parts Necessary for Each Airplane - Revised part numbers and added footnotes. 15. Paragraph 2.C.2., Parts and Materials Supplied by the Operator - Updated table. 16. Paragraph 3.A., General Information - Added caution and updated notes. 17. Paragraph 3.B., Work Instructions, Group 1 and Group 2 - Deleted step to remove the fuel boost pumps, added and revised access information, revised Figure numbers. Added LOV statement for Group 3. 18. FIGURE 1 to FIGURE 4 - Revised footnote (a). 19. FIGURE 5 and FIGURE 6 in the Original Issue were deleted. Subsequent Figures were renumbered accordingly. 20. FIGURE 8 to FIGURE 11 and FIGURE 26 to FIGURE 29 - Revised quantities. 21. FIGURE 15, FIGURE 21, FIGURE 22, FIGURE 34, FIGURE 41 and FIGURE 42 - Changed part numbers. 22. FIGURE 16, FIGURE 35 and FIGURE 36 - Revised quantities and footnote (a). 23. FIGURE 17, FIGURE 19, FIGURE 37 and FIGURE 39 - Revised Title, Sheet 1, Sheet 2 and step table. 24. FIGURE 18, FIGURE 20, FIGURE 38 and FIGURE 40 - Revised wire kit numbers and footnotes. As a part of a service bulletin validation program, this change was completed on airplane PW595 by Service Bulletin 737-28A1273 Original Issue before the release of Revision 1 of this service bulletin. The change completed on airplane PW595 by Service Bulletin 737-28A1273 Original Issue is equivalent to the release of Revision 1 of this service bulletin. Airplane PW595 has the configuration of a Group 2 airplane. As a part of a service bulletin validation program, this change was completed on airplane PS973 by Service Bulletin 737-28A1273 Revision 1, Validation Copy 1 before the release of Revision 1 of this service bulletin. The change completed on airplane PS973 by Service Bulletin 737-28A1273 Revision 1, Validation Copy 1 is equivalent to the release of Revision 1 of this service bulletin. Airplane PS973 has the configuration of a Group 2 airplane. Vertical lines are put on the left edge of each page, except in Paragraph 1.A., Effectivity and format changes, to show the location of all content changes. Pages with no vertical lines have no changes. REVISION HISTORY December 23, 2014Original Issue: Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 8 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 9 March 14, 2017Revision 1: Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 9 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 10 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 10 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT BLANK PAGE ### Page 11 Commercial Airplanes 737 Service Bulletin ALERT SummaryNumber: 737-28A1273Original Issue: December 23, 2014 Revision 1: March 14, 2017 ATA System: 2822 SUBJECT: FUEL - Engine Fuel Feed System - Wing and Center Tank Fuel Boost Pump Wire Bundle Replacement and Convoluted Liner Installation THIS DOCUMENT 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 DOCUMENT TO THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS DOCUMENT TO THE NEW OWNER. CONCURRENT REQUIREMENTS Refer to Paragraph 1.B., Concurrent Requirements. BACKGROUND This service bulletin installs new fuel boost pump wire bundles in the wing and center fuel tanks. New shielded wire bundles in convoluted liners are installed in the fuel tank conduits with wire shield grounding at the fuel boost pump housing and pressure seal. Boeing has issued this service bulletin so that the wiring and sleeve no longer need to be removed and inspected every 15,000 hours in accordance with Boeing Service Bulletin 737-28A1263 and the subject of Federal Aviation Administration (FAA) Airworthiness Directive AD 2007-24-02. If this service bulletin is not done, wire bundle damage can occur, which could cause arcing and a possible burn through condition which could result in a potential source of ignition in a fuel tank and consequent fire or explosion. Boeing Service Bulletin 737-28A1263 was issued because damage was found during the repetitive inspection in accordance with Boeing Service Bulletin 737-28A1120 and mandated by Federal Aviation Administration (FAA) Airworthiness Directive AD 99-21-15. The damage was found to the sleeve, jacket, and insulation on the electrical wire. The sleeve was worn through at three locations. At two of the locations the damage was also through the jacket of the electrical wire and exposed the insulation on the electrical wire inside the jacket. The wear did not expose the conductor of the electrical wire. The damage was found approximately 21,000 hours after installation of the sleeve. The 21,000 hours is less than the 30,000 repeat inspection interval hours specified in Federal Aviation Administration (FAA) Airworthiness Directive AD 99-21-15. Boeing has issued this service bulletin as a final solution to this condition and to replace Boeing Service Bulletin 737-28A1263. Accomplishment of this service bulletin installs new shielded wire bundles in convoluted liners in the wing and center fuel tank conduits. The convoluted liner will decrease the chance of wire bundle damage. The new shielded wiring will provide a ground path for the Ground Fault Interrupter (GFI) to trip if there is shorting in the wiring. This installation will help prevent a potential ignition sources that can cause consequent fire or explosion. The GFI is installed by Boeing Service Bulletin 737-28A1212. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 11 of 234 ### Page 12 Group 1: This change affects Airworthiness Limitations document D6-38278-CMR. The new Airworthiness Limitation (AWL) that follows is added: 28-AWL-26 (for 737-100, -200, -200C airplanes). This AWL provides maintenance instructions and replaces the requirements of Airworthiness Limitation 28-AWL-18. Group 2: This change affects Airworthiness Limitations document D6-38278-CMR. The new Airworthiness Limitation (AWL) that follows is added: 28-AWL-25 (for 737-300, -400, -500 airplanes). This AWL provides maintenance instructions and replaces the requirements of Airworthiness Limitation 28-AWL-18. Group 3: Boeing endorses the FAA rules related to Limit of Validity (LOV) and recommends immediate and permanent removal from service of any airplanes upon reaching the LOV, whether or not it is operated under FAA jurisdiction. As such, Boeing no longer provides maintenance instructions for airplanes that have accumulated flight cycles beyond the LOV. Airplanes in Group 3 (line numbers 1-291) have accumulated flight cycles beyond the LOV of the maintenance program. 14 CFR 121.1115 and 129.115 prohibit operation of an airplane beyond its LOV. As a part of a service bulletin validation program, this change was completed on airplane PW595 by Service Bulletin 737-28A1273 Original Issue before the release of Revision 1 of this service bulletin. The change completed on airplane PW595 by Service Bulletin 737-28A1273 Original Issue is equivalent to the release of Revision 1 of this service bulletin. Airplane PW595 has the configuration of a Group 2 airplane. As a part of a service bulletin validation program, this change was completed on airplane PS973 by Service Bulletin 737-28A1273 Revision 1, Validation Copy 1 before the release of Revision 1 of this service bulletin. The change completed on airplane PS973 by Service Bulletin 737-28A1273 Revision 1, Validation Copy 1 is equivalent to the release of Revision 1 of this service bulletin. Airplane PS973 has the configuration of a Group 2 airplane. Accomplishment of the work in accordance with this service bulletin gives terminating action to the repeat inspections in accordance with service bulletin 737-28A1263. Boeing Service Related Problem (SRP) 737-SRP-28-0113 is related to this service bulletin. 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 Paragraph 1.I., Electrical Load DataNoElectrical Load Changed Paragraph 1.K., Publications AffectedYesPublications Affected Paragraph 1.K., Publications AffectedNoAirplane Flight Operations Affected (Flight Crew Operations Manual and/or FAA Approved Air- plane Flight Manual) Paragraph 2.C.1., Kits/PartsYesKits/Parts Required Paragraph 2.C.2., Parts and Materials Supplied by the Operator YesOperator Supplied Parts/Material Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 12 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 13 ReferenceAffectedPlanning Data Paragraph 2.F., Special Tooling Necessary to do this Service Bulletin NoSpecial Tooling Required ACTION (PRR 35005-283RS) Group 1-2: Get access to the forward cargo compartment between stations 500A and 520. Install new ground bracket at station 520 on the left and right side of the forward cargo compartment. Get access to the left wing and right wing leading edge, tank No.1 and tank No.2 aft fuel boost pumps, left and right center tank fuel boost pumps, and center fuselage splice areas. Remove or stow fuel boost pump wire bundles from between the left, right and center fuel boost pumps and the center fuselage splice area. Do a test of the fuel boost pump conduits for leaks, and repair or replace conduit if any leak is found. Install new wire bundles and convoluted liners in the left, right, and center fuel boost pump conduits and connect wire bundles to each fuel boost pump. Route new wire bundles along the left and right wing leading edge to center fuselage splice area and connect. Do a test of the fuel boost pumps. Close tank No.1 and tank No.2 aft fuel boost pump access panels, and left and right center tank fuel boost pump access panels. Close access to the forward cargo compartment between stations 500A and 520. Group 3: Boeing endorses the FAA rules related to Limit of Validity (LOV) and recommends immediate and permanent removal from service of any airplanes upon reaching the LOV, whether or not it is operated under FAA jurisdiction. As such, Boeing no longer provides maintenance instructions for airplanes that have accumulated flight cycles beyond the LOV. Airplanes in Group 3 (line numbers 1-291) have accumulated flight cycles beyond the LOV of the maintenance program. 14 CFR 121.1115 and 129.115 prohibit operation of an airplane beyond its LOV. EFFECTIVITY 737-100, -200, -200C, -300, -400, -500 Airplanes. Refer to Paragraph 1.A., Effectivity, for the list of affected airplane(s). 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. Group 1-2: Boeing recommends that the change given in this service bulletin be done within 60 months after the original issue date of this service bulletin. Group 3: Boeing endorses the FAA rules related to Limit of Validity (LOV) and recommends immediate and permanent removal from service of any airplanes upon reaching the LOV, whether or not it is operated under FAA jurisdiction. As such, Boeing no longer provides maintenance instructions for airplanes that have accumulated flight cycles beyond the LOV. Airplanes in Group 3 (line numbers 1-291) have accumulated flight cycles beyond the LOV of the maintenance program. 14 CFR 121.1115 and 129.115 prohibit operation of an airplane beyond its LOV. INDUSTRY SUPPORT INFORMATION Boeing warranty remedies are not available for the configuration changes given in this service bulletin. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 13 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 14 MANPOWER Refer to Paragraph 1.G., Manpower. MATERIAL INFORMATION Boeing Supplied Kits. Operator Supplied Materials. Refer to Paragraph 2.A., Material - Price and Availability. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 14 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 15 (OCR) BOEING SERVICE BULLETIN 737-28A1273 ALERT ALERT GROUP 1-2 AIRPLANES: PULL WIRE BUNDLES AND TEFLON SLEEVES OUT OF THE FUEL TANK CONDUITS. REMOVE OR STOW WIRE BUNDLES. CLEAN FUEL TANK CONDUITS AND INSPECT FOR LEAKS. INSTALL NEW WIRE BUNDLES AND NEW CONVOLUTED LINERS INTO FUEL TANK CONDUITS. ROUTE WIRE BUNDLES TO SPLICE AREA AND GROUND BRACKETS IN THE FUSELAGE AND CONNECT. GROUP 1-2 AIRPLANES: GROUP 1-2 AIRPLANES INSTALL NEW GROUNDING BOAT NEN WIRE BUNDLES TO FUEL BOOST PUMP SLE BRACKETS. INSTALL AND TEST FUEL BOOST PUMPS. 1860695 Original Issue: December 23, 2014 Revision 1: March 14, 2017 Export Controlled ECCN: 9E991 - BOEING 737-28A1273 PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 15 of 234 ### Page 16 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 16 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT BLANK PAGE ### Page 17 Commercial Airplanes 737 Service Bulletin ALERT Number: 737-28A1273 Original Issue: December 23, 2014 Revision 1: March 14, 2017 ATA System: 2822 SUBJECT: FUEL - Engine Fuel Feed System - Wing and Center Tank Fuel Boost Pump Wire Bundle Replacement and Convoluted Liner Installation THIS DOCUMENT 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 DOCUMENT TO THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS DOCUMENT 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. Refer to PRR 35005-283RS for data about this change. DESCRIPTIONCONFIGURATIONGROUP 737-200, -200C Airplane line numbers 292 thru 1585.-1 737-300, -400, -500 Airplane line numbers 1001 thru 3132.-2 737-100, -200, -200C Airplane line numbers 1 thru 291.-3 Airplane Models: 737-100, 737-200, 737-200C, 737-300, 737-400, 737-500 GroupVariable Number 3PA001 - PA022 3PA099 3PA231 - PA232 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 17 of 234 ### Page 18 GroupVariable Number 3PC001 - PC005 3PG001 - PG075 3PG199 3PG201 - PG230 3PG251 - PG255 3PG271 - PG279 3PG301 - PG314 3PG331 - PG332 3PG351 - PG356 3PG375 3PG401 - PG403 3PG431 - PG442 3PG471 - PG475 3PG501 - PG505 3PG571 - PG583 1PG584 - PG586 3PG621 - PG630 3PG651 - PG652 3PG701 - PG705 1PH001 1PH011 - PH013 1PH021 - PH024 3PH701 - PH715 3PH731 - PH732 3PH741 - PH742 1PH743 3PJ001 - PJ002 1PJ003 - PJ009 3PJ031 - PJ032 3PJ071 - PJ072 3PJ101 - PJ104 1PJ105 - PJ119 1PJ201 - PJ219 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 18 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 19 GroupVariable Number 2PJ301 - PJ302 2PJ551 - PJ561 2PJ601 - PJ615 2PJ811 2PJ816 - PJ817 1PK026 - PK029 1PK041 - PK053 1PK061 - PK070 1PK081 - PK082 1PK091 - PK099 1PK101 - PK103 1PK111 - PK120 1PK141 - PK146 1PK201 - PK204 1PK211 - PK223 1PK231 - PK241 1PK251 - PK258 1PK271 - PK274 1PK281 - PK289 1PK291 1PK301 - PK318 1PK341 1PK351 - PK361 1PK391 1PK431 - PK433 1PK451 - PK452 1PK461 - PK469 1PK495 1PK501 - PK504 1PK511 - PK515 1PK519 1PK521 - PK528 1PK541 - PK565 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 19 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 20 GroupVariable Number 1PK581 1PK591 - PK599 1PK601 - PK617 1PK621 - PK637 1PK641 - PK642 1PK661 - PK666 1PK671 - PK681 1PK691 - PK697 1PK711 - PK716 1PK731 - PK765 1PK771 - PK779 1PK801 - PK804 1PK819 - PK827 1PK830 1PK861 - PK863 1PK871 - PK874 1PK881 - PK884 1PK901 - PK938 1PK971 - PK974 1PL001 - PL028 1PL061 1PL081 1PL101 - PL113 1PL151 1PL171 - PL172 1PL201 - PL203 1PL221 1PL401 - PL417 1PL421 1PL441 1PL451 - PL456 1PL471 1PL491 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 20 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 21 GroupVariable Number 1PL501 - PL506 1PL551 - PL562 1PL581 1PL601 - PL603 1PL611 1PL621 - PL626 1PL631 - PL632 3PL711 - PL712 3PL716 1PL717 - PL747 1PL756 1PL758 1PL761 - PL770 1PL781 - PL788 1PL793 3PL801 - PL803 1PM001 - PM006 1PM016 - PM017 1PM021 - PM023 1PM051 - PM066 1PM101 - PM119 1PM141 - PM142 1PM171 1PM181 1PM251 - PM255 1PM281 - PM283 2PM381 - PM399 2PM401 - PM417 2PM541 - PM564 1PN001 - PN002 1PN021 - PN043 1PN081 - PN086 1PN101 - PN117 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 21 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 22 GroupVariable Number 1PN131 - PN163 1PN401 - PN420 1PN431 - PN433 1PN451 - PN456 1PN471 - PN474 1PN481 1PN491 - PN493 1PN501 - PN502 1PN511 - PN512 1PN521 2PP001 - PP054 2PP101 - PP169 2PP181 - PP199 2PP201 - PP205 2PP221 2PP231 - PP243 2PP281 - PP286 2PP301 - PP305 2PP351 - PP353 2PP376 - PP384 2PP391 - PP393 2PP401 - PP440 2PP471 - PP475 2PP501 - PP522 2PP631 - PP634 2PP651 - PP652 2PP671 - PP699 2PP701 - PP733 2PP771 - PP779 2PP801 - PP808 2PP821 - PP827 2PP831 - PP848 2PP851 - PP852 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 22 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 23 GroupVariable Number 2PP861 - PP877 2PP891 - PP899 2PP901 - PP936 2PP946 - PP948 2PP951 - PP952 2PP961 - PP967 2PP981 - PP991 2PP993 2PQ001 - PQ016 2PQ026 - PQ041 2PQ051 - PQ092 2PQ101 - PQ199 2PQ201 - PQ202 2PQ221 - PQ237 2PQ241 - PQ243 2PQ251 - PQ267 2PQ281 - PQ299 2PQ301 - PQ307 2PQ331 - PQ332 2PQ341 - PQ348 2PQ361 - PQ373 2PQ391 - PQ395 2PQ401 - PQ418 2PQ421 2PQ431 - PQ438 2PQ447 - PQ448 2PQ451 2PQ454 2PQ471 - PQ475 2PQ479 - PQ481 2PQ486 - PQ487 2PQ491 - PQ493 2PQ771 - PQ772 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 23 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 24 GroupVariable Number 2PQ791 - PQ793 2PQ801 - PQ805 2PQ931 - PQ935 2PQ951 2PQ971 - PQ997 2PR001 - PR017 2PR021 - PR034 2PR041 - PR045 2PR061 - PR072 2PR077 - PR082 2PR091 - PR092 2PR096 2PR101 2PR121 - PR122 2PR131 - PR132 2PR141 - PR143 2PR161 - PR172 2PR181 2PS601 - PS631 2PS636 - PS638 2PS641 - PS644 2PS651 - PS657 2PS666 - PS669 2PS691 - PS692 2PS701 - PS706 2PS751 - PS799 2PS811 2PS836 - PS837 2PS841 - PS846 2PS851 - PS852 2PS856 2PS861 - PS863 2PS866 - PS868 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 24 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 25 GroupVariable Number 2PS871 - PS874 2PS896 - PS897 2PS901 - PS941 2PS956 - PS957 2PS961 - PS963 2PS971 - PS978 2PT001 - PT015 2PT021 - PT031 2PT041 - PT064 2PT101 - PT105 2PT121 - PT138 2PT146 - PT148 2PT161 - PT170 2PT181 - PT188 2PT211 - PT220 2PT295 2PT301 - PT309 2PT331 - PT360 2PT381 - PT399 2PT401 - PT438 2PT501 - PT517 2PT561 - PT565 2PT581 - PT586 2PT611 - PT621 2PT641 - PT644 2PT651 - PT656 2PT671 - PT672 2PT681 - PT685 2PT701 - PT703 2PT716 - PT717 2PT721 - PT725 2PT801 - PT834 2PT851 - PT854 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 25 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 26 GroupVariable Number 2PT871 - PT886 2PT901 - PT930 2PT971 - PT973 2PT981 - PT985 2PT996 2PU001 - PU025 2PU301 2PU311 - PU313 2PV001 - PV055 2PV201 - PV209 2PV226 - PV229 2PV231 - PV237 2PV271 - PV272 2PV281 - PV287 2PV296 2PV301 - PV302 2PV351 2PV356 - PV357 2PW001 - PW054 2PW061 - PW068 2PW072 2PW086 - PW088 2PW091 - PW094 2PW101 - PW102 2PW106 2PW111 - PW120 2PW156 - PW157 2PW161 - PW171 2PW201 - PW252 2PW261 - PW268 2PW271 - PW276 2PW278 2PW281 - PW293 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 26 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 27 GroupVariable Number 2PW296 2PW301 - PW327 2PW401 - PW408 2PW411 - PW418 2PW421 - PW424 2PW431 - PW435 2PW441 - PW450 2PW461 - PW467 2PW501 - PW504 2PW511 - PW522 2PW524 - PW550 2PW556 - PW557 2PW561 - PW564 2PW571 - PW576 2PW591 - PW596 2PW611 - PW622 2PW631 - PW637 2PW661 - PW662 2PW681 - PW683 2PW701 - PW702 2PW711 - PW717 2PW741 - PW742 2PW761 2PW771 2PW831 2PW851 - PW856 3PX071 3PX701 3PY001 - PY008 3PY021 1PY022 3PY031 1PY036 - PY037 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 27 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 28 GroupVariable Number 1PY046 - PY048 1PY051 - PY053 1PY056 - PY057 1PY101 - PY103 1PY111 - PY113 1PY131 - PY135 1PY141 - PY143 1PY151 - PY154 1PY156 - PY157 1PY161 - PY162 1PY166 1PY191 1PY201 1PY221 - PY222 1PY231 1PY241 - PY244 1PY270 - PY275 1PY281 1PY286 3PY301 - PY304 3PY321 - PY323 3PY341 - PY346 3PY361 - PY362 3PY381 1PY401 1PY409 - PY411 1PY421 - PY422 1PY441 1PY451 1PY461 - PY463 1PY591 - PY595 1PY611 - PY612 1PY621 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 28 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 29 GroupVariable Number 1PY631 1PY651 1PY671 - PY672 1PY721 1PY741 2. Spares Affected None. B. Concurrent Requirements The Airworthiness Limitations (AWLs) and Certification Maintenance Requirements (CMRs) listed below must be added to the airplanes maintenance program before or at the same time as this service bulletin. DescriptionAWLDocumentCompany Fuel Boost Pump Wires in Conduit Installation - In Fuel Tank. 737- 100/200/200C airplanes that have incorporated Service Bulletin 737- 28A1263, but have not incorporated Service Bulletin 737-28A1273. 28-AWL- 18 D6-38278-CMR, 737-12345 Airwor- thiness Limitations (AWLs)/Certifica- tion Maintenance Requirements (CMRs), Revision May 2016 or later revisions. Boeing Fuel Boost Pump Wires in Conduit Installation - In Fuel Tank. 737- 100/200/200C airplanes that have incorporated Service Bulletin 737- 28A1273. 28-AWL- 26 Fuel Boost Pump Wires in Conduit Installation - In Fuel Tank. 737- 300/400/500 airplanes that have in- corporated Service Bulletin 737- 28A1263, but have not incorporated Service Bulletin 737-28A1273. 28-AWL- 18 Fuel Boost Pump Wires in Conduit Installation - In Fuel Tank. 737- 300/400/500 airplanes that have in- corporated Service Bulletin 737- 28A1273. 28-AWL- 25 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 29 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 30 C. Reason This service bulletin installs new fuel boost pump wire bundles in the wing and center fuel tanks. New shielded wire bundles in convoluted liners are installed in the fuel tank conduits with wire shield grounding at the fuel boost pump housing and pressure seal. Boeing has issued this service bulletin so that the wiring and sleeve no longer need to be removed and inspected every 15,000 hours in accordance with Boeing Service Bulletin 737-28A1263 and the subject of Federal Aviation Administration (FAA) Airworthiness Directive AD 2007-24-02. If this service bulletin is not done, wire bundle damage can occur, which could cause arcing and a possible burn through condition which could result in a potential source of ignition in a fuel tank and consequent fire or explosion. Boeing Service Bulletin 737-28A1263 was issued because damage was found during the repetitive inspection in accordance with Boeing Service Bulletin 737-28A1120 and mandated by Federal Aviation Administration (FAA) Airworthiness Directive AD 99-21-15. The damage was found to the sleeve, jacket, and insulation on the electrical wire. The sleeve was worn through at three locations. At two of the locations the damage was also through the jacket of the electrical wire and exposed the insulation on the electrical wire inside the jacket. The wear did not expose the conductor of the electrical wire. The damage was found approximately 21,000 hours after installation of the sleeve. The 21,000 hours is less than the 30,000 repeat inspection interval hours specified in Federal Aviation Administration (FAA) Airworthiness Directive AD 99-21-15. Boeing has issued this service bulletin as a final solution to this condition and to replace Boeing Service Bulletin 737-28A1263. Accomplishment of this service bulletin installs new shielded wire bundles in convoluted liners in the wing and center fuel tank conduits. The convoluted liner will decrease the chance of wire bundle damage. The new shielded wiring will provide a ground path for the Ground Fault Interrupter (GFI) to trip if there is shorting in the wiring. This installation will help prevent a potential ignition sources that can cause consequent fire or explosion. The GFI is installed by Boeing Service Bulletin 737-28A1212. Group 1: This change affects Airworthiness Limitations document D6-38278-CMR. The new Airworthiness Limitation (AWL) that follows is added: 28-AWL-26 (for 737-100, -200, -200C airplanes). This AWL provides maintenance instructions and replaces the requirements of Airworthiness Limitation 28-AWL-18. Group 2: This change affects Airworthiness Limitations document D6-38278-CMR. The new Airworthiness Limitation (AWL) that follows is added: 28-AWL-25 (for 737-300, -400, -500 airplanes). This AWL provides maintenance instructions and replaces the requirements of Airworthiness Limitation 28-AWL-18. Group 3: Boeing endorses the FAA rules related to Limit of Validity (LOV) and recommends immediate and permanent removal from service of any airplanes upon reaching the LOV, whether or not it is operated under FAA jurisdiction. As such, Boeing no longer provides maintenance instructions for airplanes that have accumulated flight cycles beyond the LOV. Airplanes in Group 3 (line numbers 1-291) have accumulated flight cycles beyond the LOV of the maintenance program. 14 CFR 121.1115 and 129.115 prohibit operation of an airplane beyond its LOV. Accomplishment of the work in accordance with this service bulletin gives terminating action to the repeat inspections in accordance with service bulletin 737-28A1263. Boeing Service Related Problem (SRP) 737-SRP-28-0113 is related to this service bulletin. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 30 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 31 Revision 1 is sent to incorporate changes found during two validations of this service bulletin. This revision also deletes two figures that remove the fuel boost pumps, because removal of the fuel boost pumps is not necessary. Subsequent Figures are renumbered accordingly. D. Description Group 1-2: Get access to the forward cargo compartment between stations 500A and 520. Install new ground bracket at station 520 on the left and right side of the forward cargo compartment. Get access to the left wing and right wing leading edge, tank No.1 and tank No.2 aft fuel boost pumps, left and right center tank fuel boost pumps, and center fuselage splice areas. Remove or stow fuel boost pump wire bundles from between the left, right and center fuel boost pumps and the center fuselage splice area. Do a test of the fuel boost pump conduits for leaks, and repair or replace conduit if any leak is found. Install new wire bundles and convoluted liners in the left, right, and center fuel boost pump conduits and connect wire bundles to each fuel boost pump. Route new wire bundles along the left and right wing leading edge to center fuselage splice area and connect. Do a test of the fuel boost pumps. Close tank No.1 and tank No.2 aft fuel boost pump access panels, and left and right center tank fuel boost pump access panels. Close access to the forward cargo compartment between stations 500A and 520. Group 3: Boeing endorses the FAA rules related to Limit of Validity (LOV) and recommends immediate and permanent removal from service of any airplanes upon reaching the LOV, whether or not it is operated under FAA jurisdiction. As such, Boeing no longer provides maintenance instructions for airplanes that have accumulated flight cycles beyond the LOV. Airplanes in Group 3 (line numbers 1-291) have accumulated flight cycles beyond the LOV of the maintenance program. 14 CFR 121.1115 and 129.115 prohibit operation of an airplane beyond its LOV. Revision 1 - Effects of this Revision on airplanes on which the Original Issue was previously done: None. The work in this service bulletin is done in the maintenance zone(s) given below. Group 1: Affected Maintenance Zones ZoneModel 3-3, 3-5, 4-3, 4-5737-200, 737-200C Group 2: Affected Maintenance Zones ZoneModel 303, 305, 403, 405737-300, 737-400, 737-500 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 31 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 32 Group 3: Affected Maintenance Zones ZoneModel 3-3, 3-5, 4-3, 4-5737-100, 737-200, 737-200C E. 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. Group 1-2: Boeing recommends that the change given in this service bulletin be done within 60 months after the original issue date of this service bulletin. Group 3: Boeing endorses the FAA rules related to Limit of Validity (LOV) and recommends immediate and permanent removal from service of any airplanes upon reaching the LOV, whether or not it is operated under FAA jurisdiction. As such, Boeing no longer provides maintenance instructions for airplanes that have accumulated flight cycles beyond the LOV. Airplanes in Group 3 (line numbers 1-291) have accumulated flight cycles beyond the LOV of the maintenance program. 14 CFR 121.1115 and 129.115 prohibit operation of an airplane beyond its LOV. 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. In addition, the Manager of the FAA Seattle Aircraft Certification Office approves the action (i.e., inspection or modification) defined in this service bulletin, in combination with incorporation of Airworthiness Limitation (AWL) No. 28-AWL-18 and 28-AWL-26 for the 737-100/200/200C airplanes, AWL No. 28-AWL-18 and 28-AWL-25 for the 737-300/400/500 airplanes, from the Boeing Document D6-38278-CMR, 737-12345 Airworthiness Limitations (AWLs)/Certification Maintenance Requirements (CMRs), Revision May 2016 or later revisions, into the operator's maintenance program, as an alternative method of compliance to the requirements of paragraphs (f), (i) and (j) of AD 2007-24-02. FAA approved revision May 2016 or later revisions of the D6-38278-CMR must be used. The accomplishment of the modification defined in this service bulletin terminates the repeat inspections required by paragraph (f) of AD 2007-24-02. All provisions of AD 2007-24-02 that are not specifically referenced in the above statement remain fully applicable and must be complied with accordingly. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 32 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 33 G. Manpower The table below shows an estimate of the task hours necessary to do this service bulletin 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. Group 1: Elapsed Hours Task HoursNumber of Persons Task 3.5014.004Open Access 2.002.001FIGURE 1 2.002.001FIGURE 3 2.002.001FIGURE 5 0.300.301FIGURE 6 0.300.301FIGURE 7 4.004.001FIGURE 8 3.003.001FIGURE 10 ---FIGURE 12 (Wire routing only) 2.655.302FIGURE 13 Option 1: Remove wire bundle W512 0.600.601FIGURE 13 Option 2: Cap and stow wire bundle W512 2.755.502FIGURE 14 Option 1: Remove wire bundle W514 0.600.601FIGURE 14 Option 2: Cap and stow wire bundle W514 3.503.501FIGURE 15 4.004.001FIGURE 16 1.751.751FIGURE 17 5.0010.002FIGURE 18 1.751.751FIGURE 19 5.0010.002FIGURE 20 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 33 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 34 Group 1: Elapsed Hours Task HoursNumber of Persons Task 0.500.501FIGURE 21 2.002.001FIGURE 23 0.300.301FIGURE 24 0.300.301FIGURE 25 3.003.001FIGURE 26 4.004.001FIGURE 28 ---FIGURE 30 (Wire routing only) 2.655.302FIGURE 32 Option 1: Remove wire bundle W516 0.600.601FIGURE 32 Option 2: Cap and stow wire bundle W516 2.755.502FIGURE 33 Option 1: Remove wire bundle W520 0.600.601FIGURE 33 Option 2: Cap and stow wire bundle W520 3.503.501FIGURE 34 4.004.001FIGURE 35 1.751.751FIGURE 37 5.0010.002FIGURE 38 1.751.751FIGURE 39 5.0010.002FIGURE 40 0.500.501FIGURE 41 7.5030.004Close Access 1.701.701Test (a)(a)TOTAL FOR EACH AIRPLANE (a) The total Task Hours and Elapsed Hours are not given as the work done on each airplane is variable. Group 2: Elapsed Hours Task HoursNumber of Persons Task 3.5014.004Open Access 2.002.001FIGURE 2 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 34 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 35 Group 2: Elapsed Hours Task HoursNumber of Persons Task 2.002.001FIGURE 4 2.002.001FIGURE 5 0.300.301FIGURE 6 0.300.301FIGURE 7 4.004.001FIGURE 9 3.003.001FIGURE 11 ---FIGURE 12 (Wire routing only) 2.655.302FIGURE 13 Option 1: Remove wire bundle W512 0.600.601FIGURE 13 Option 2: Remove wire bundle W512 2.755.502FIGURE 14 Option 1: Remove wire bundle W514 0.600.601FIGURE 14 Option 2: Remove wire bundle W514 3.503.501FIGURE 15 4.004.001FIGURE 16 1.751.751FIGURE 17 5.0010.002FIGURE 18 1.751.751FIGURE 19 5.0010.002FIGURE 20 0.500.501FIGURE 22 2.002.001FIGURE 23 0.300.301FIGURE 24 0.300.301FIGURE 25 3.003.001FIGURE 27 4.004.001FIGURE 29 ---FIGURE 31 (Wire routing only) 2.655.302FIGURE 32 Option 1: Remove wire bundle W516 0.600.601FIGURE 32 Option 2: Cap and stow wire bundle W516 2.755.502FIGURE 33 Option 1: Remove wire bundle W520 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 35 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 36 Group 2: Elapsed Hours Task HoursNumber of Persons Task 0.600.601FIGURE 33 Option 2: Cap and stow wire bundle W520 3.503.501FIGURE 34 4.004.001FIGURE 36 1.751.751FIGURE 37 5.0010.002FIGURE 38 1.751.751FIGURE 39 5.0010.002FIGURE 40 0.500.501FIGURE 42 7.5030.004Close Access 1.701.701Test (a)(a)TOTAL FOR EACH AIRPLANE (a) The total Task Hours and Elapsed Hours are not given as the work done on each airplane is variable. Group 3: Boeing endorses the FAA rules related to Limit of Validity (LOV) and recommends immediate and permanent removal from service of any airplanes upon reaching the LOV, whether or not it is operated under FAA jurisdiction. As such, Boeing no longer provides maintenance instructions for airplanes that have accumulated flight cycles beyond the LOV. Airplanes in Group 3 (line numbers 1-291) have accumulated flight cycles beyond the LOV of the maintenance program. 14 CFR 121.1115 and 129.115 prohibit operation of an airplane beyond its LOV. H. Weight and Balance Changes Group 1: Change in Moment (Pound-Inches) Change in Weight (Pounds)Airplane + 1016.4+ 2.1737-200, -200C Group 2: Change in Moment (Pound-Inches) Change in Weight (Pounds)Airplane + 836.0+ 1.9737-300 + 699.2+ 1.9737-400 + 938.6+ 1.9737-500 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 36 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 37 Group 3: Change in Moment (Pound-Inches) Change in Weight (Pounds)Airplane NoneNone737-100, -200, - 200C I. Electrical Load Data Not changed. J. References 1. Existing Data: a. Engineering Change Memo PRR 35005-283RS b. Boeing Service Bulletin 737-28A1120, 737-28A1212, 737-28A1263 c. Boeing Service Related Problem (SRP) 737-SRP-28-0113 d. Federal Aviation Administration (FAA) Airworthiness Directive (AD) 2007-24-02, 99-21-15 e. Standard Overhaul Practices Manual (SOPM) 20-11-03, 20-41-02, 20-43-03, 20-50-00, 20-50-01, 20-50-02, 20-50-05, 20-50-19 f. Standard Wiring Practices Manual (SWPM) 20-00-10, 20-00-11, 20-10-11, 20-10-12, 20-10-15, 20-10-19, 20-10-20, 20-20-00, 20-20-10, 20-30-11, 20-30-12, 20-30-16, 20-30-22, 20-60-07, 20-60-08, 20-60-09, 20-61-11 g. 737-100/200 Aircraft Maintenance Manual (AMM) 12-11-02, 12-31-21, 12-31-61, 12-31-71, 20-10-51, 21-21-00, 25-52-111, 25-52-131, 27-81-00, 28-10-00, 28-22-41, 28-23-00, 52-31-00, 57-30-11 h. 737-100/200 Structural Repair Manual (SRM) 51-30-02 i. 737-100/200 Wiring Diagram Manual (WDM) 28-23-01 j. 737-300/400/500 Aircraft Maintenance Manual (AMM) 12-11-02, 12-31-21, 12-31-61, 12-31-71, 20-10-51, 21-21-00, 25-52-65, 25-52-81, 27-81-00, 28-10-00, 28-11-52, 28-22-41, 28-23-00, 52-31-00, 57-30-11 k. Airworthiness Limitation (AWL) and Certification Maintenance Requirements (CMR) 28-AWL-18 for 737-100/200/200C l. Airworthiness Limitation (AWL) and Certification Maintenance Requirements (CMR) 28-AWL-26 for 737-100/200/200C m. Airworthiness Limitation (AWL) and Certification Maintenance Requirement (CMR) 28-AWL-18 for 737-300/400/500 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 37 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 38 n. Airworthiness Limitation (AWL) and Certification Maintenance Requirement (CMR) 28-AWL-25 for 737-300/400/500 o. 737-300/400/500 Wiring Diagram Manual (WDM) 28-23-01 p. 737-300 Structural Repair Manual (SRM) 51-40-02 q. 737-400 Structural Repair Manual (SRM) 51-40-02 r. 737-500 Structural Repair Manual (SRM) 51-40-02 2. Data Supplied with this Service Bulletin: None. 3. Installation Drawings Used in the Preparation of this Service Bulletin: TitleDrawing Number Wire Bundle Instl. LH Leading Edge & Front Spar65-48301 Wire Bundle Instl. RH Leading Edge & Front Spar65-48302 Wire Bundle Instl - Sec 20 LH Inboard Inspar WBL 71.24 - WBL 227 65-48303 Wire Bundle Instl - Sec 20 RH Inboard Inspar WBL 71.24 - WBL 227 65-48304 Wire Bundle Installation - FWD Cargo Compartment65-48331 Wire Instl Kit, Fuel Boost Pump - Wiring Change65C38810 The table above lists applicable drawings used to prepare this service bulletin. The drawings are not necessary to make the specified changes, and are not supplied with this service bulletin. The drawings may not be applicable to all airplane configurations or operators. K. Publications Affected 1. Publications: Chapter-SectionPublication Section C.1D6-38278-CMR, 737-12345 Airworthiness Limitations (AWLs)/Certification Maintenance Requirements (CMRs), Revision May 2016 or later revisions 28-22737 Aircraft Maintenance Manual 28-23737 Wiring Diagram Manual 28-41, 47-31737-100/200 Illustrated Parts Catalog 28-40737-300/400/500 Illustrated Parts Catalog 28-22737 System Schematic Manual Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 38 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 39 2. Damage Tolerance Based Structural Inspections: Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the Maintenance Program. This service bulletin affects FCS but no new DTIs are necessary. L. Interchangeability and Intermixability of Parts Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts. M. Software Accomplishment Summary Not affected. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 39 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 40 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 40 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT BLANK PAGE ### Page 41 2. MATERIAL INFORMATION A. Material - Price and Availability Boeing can supply the kits shown in Paragraph 2.C., Parts Necessary for Each Airplane. Operators are encouraged to share schedule requirements with Boeing for incorporation of the service bulletin. The kits are subject to the terms and conditions of the Boeing standard purchase order acknowledgment. Prices are in United States Dollars. Terms: Net 30 days. Reference this service bulletin and submit your purchase order by one of these methods: 1. Order on-line via ATA Spec 2000 or The Boeing PART Page 2. Fax to (206) 662-7145 Group 1: REFER TO THE BOEING PART PAGE ON MYBOEINGFLEET.COM OR CONTACT FIRST RESPONDER AT FR@BOEING.COM FOR THE LATEST REORDER LEAD TIME (ROLT) AND PRICE INFORMATION Unit Price as of the Re- vision 1 date of this Service Bulletin (US Dollars) ROLT as of the Revision 1 date of this Service Bul- letin (Calendar Days) QTYDateNameKit Number $5,561.003531Sept 20, 2016Top Kit - Grounding Bracket, Boost Pump Wiring 65C38809-2 75Mar 02, 2017 43Mar 09, 2017 Group 2: REFER TO THE BOEING PART PAGE ON MYBOEINGFLEET.COM OR CONTACT FIRST RESPONDER AT FR@BOEING.COM FOR THE LATEST REORDER LEAD TIME (ROLT) AND PRICE INFORMATION Unit Price as of the Re- vision 1 date of this Service Bulletin (US Dollars) ROLT as of the Revision 1 date of this Service Bul- letin (Calendar Days) QTYDateNameKit Number $5,525.003531Sept 20, 2016Top Kit - Grounding Bracket, Boost Pump Wiring 65C38809-1 90Mar 02, 2017 90Mar 09, 2017 108Mar 16, 2017 Group 3: Boeing endorses the FAA rules related to Limit of Validity (LOV) and recommends immediate and permanent removal from service of any airplanes upon reaching the LOV, whether or not it is operated under FAA jurisdiction. As such, Boeing no longer provides maintenance instructions for airplanes that have accumulated flight cycles beyond the LOV. Airplanes in Group 3 (line numbers 1-291) have accumulated flight cycles beyond the LOV of the maintenance program. 14 CFR 121.1115 and 129.115 prohibit operation of an airplane beyond its LOV. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 41 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 42 The parts that follow are only necessary for the replacement of the existing fuel tank conduit(s). Group 1: REFER TO THE BOEING PART PAGE ON MYBOEINGFLEET.COM OR CONTACT FIRST RESPONDER AT FR@BOEING.COM FOR THE LATEST REORDER LEAD TIME (ROLT) AND PRICE INFORMATION Unit Price as of the original issue date of this Service Bulletin (US Dollars) ROLT as of the original issue date of this Service Bulletin (Calendar Days) NameKit Number $992.00-TUBE ASSY65-46509-157 $1,034.00-TUBE ASSY65-46509-158 $933.00-TUBE ASSY65-46509-163 $986.00-TUBE ASSY65-46509-164 $855.00-TUBE ASSY65-46509-165 $955.00-CONDUIT ASSY65-46509-166 Group 2: REFER TO THE BOEING PART PAGE ON MYBOEINGFLEET.COM OR CONTACT FIRST RESPONDER AT FR@BOEING.COM FOR THE LATEST REORDER LEAD TIME (ROLT) AND PRICE INFORMATION Unit Price as of the original issue date of this Service Bulletin (US Dollars) ROLT as of the original issue date of this Service Bulletin (Calendar Days) NameKit Number $1,066.00-TUBE ASSY-ELECTRICAL CONDUIT, BOOST PUMP 65C26901-38 $800.00-TUBE ASSY-ELECTRICAL CONDUIT, BOOST PUMP 65C26901-47 $1,457.00-TUBE ASSY-ELECTRICAL CONDUIT, BOOST PUMP 65C26901-48 $563.00-TUBE ASSY-ELECTRICAL CONDUIT, BOOST PUMP 65C26901-49 $835.00-TUBE ASSY-ELECTRICAL CONDUIT, BOOST PUMP 65C26901-88 $875.00-TUBE ASSY65C26901-91 $646.00-TUBE ASSY65C26901-135 Group 3: Boeing endorses the FAA rules related to Limit of Validity (LOV) and recommends immediate and permanent removal from service of any airplanes upon reaching the LOV, whether or not it is operated under FAA jurisdiction. As such, Boeing no longer provides maintenance instructions for airplanes that have accumulated flight cycles beyond the LOV. Airplanes in Group 3 (line numbers 1-291) have accumulated flight cycles beyond the LOV of the maintenance program. 14 CFR 121.1115 and 129.115 prohibit operation of an airplane beyond its LOV. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 42 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 43 Operators are encouraged to complete the survey provided in APPENDIX B of this service bulletin to help Boeing predict the quantity and timing of the Boeing Supplied Kits/Parts. B. Industry Support Information Boeing warranty remedies are not available for the configuration changes given in this service bulletin. C. Parts Necessary for Each Airplane 1. Kits/Parts To get the kits/parts shown below, refer to Paragraph 2.A., Material - Price and Availability. NOTE: One top kit and the items shown in Paragraph 2.C.2., Parts and Materials Supplied by the Operator, are necessary for each airplane. Group 1-2: Kit 65C38809 NotesExisting Part Number NameQtyNew Part Number -2-1 TOP KIT - GROUNDING BRACKET, BOOST PUMP WIRING. 737-300/- 400/-500 .-65C38809-1 TOP KIT - GROUNDING BRACKET, BOOST PUMP WIRING. 737-100/- 200 -.65C38809-2 WIRE KIT - FINAL BOOST PUMP WIRING - WITH CENTER TANKS 1161-74492-1 KIT INSTL - GROUNDING BRACKET, BOOST PUMP WIRING .165C38810-1 KIT INSTL - GROUNDING BRACKET, BOOST PUMP WIRING 1.65C38810-2 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 43 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 44 Group 1-2: Kit 65C38809 NotesExisting Part Number NameQtyNew Part Number -2-1 KIT-INSTL, CON- DUIT TERMINAL SHIELD 1165C38811-1 ALL Kit 61-74492 NotesExisting Part Number NameQtyNew Part Number -133-132W-132-131W-131-1 WIRE KIT - FINAL BOOST PUMP WIRING - WITH CENTER TANKS .....-61-74492-1 ASSY - W512....-.61-74492-131 WIRE LIST...-..61-74492-131W ASSY - W514..-...61-74492-132 WIRE LIST.-....61-74492-132W ASSY - W516-.....61-74492-133 TERMINAL2.2.2.322320 ASSY - W512.....161-74492-131 ASSY - W512 - PARTIAL PREFAB OF WIRING ....1.61-74492-131A ASSY - W514.....161-74492-132 ASSY - W514 - PARTIAL PREFAB OF WIRING ..1...61-74492-132A ASSY - W516.....161-74492-133 ASSY - W516 - PARTIAL PREFAB OF WIRING 1.....61-74492-133A ASSY - W520.....161-74492-134 Assy - W512 SUP- PLEMENTAL .....161-74492-231 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 44 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 45 ALL Kit 61-74492 NotesExisting Part Number NameQtyNew Part Number -133-132W-132-131W-131-1 Assy - W514 SUP- PLEMENTAL .....161-74492-232 Assy - W516 SUP- PLEMENTAL .....161-74492-233 Assy - W520 SUP- PLEMENTAL .....161-74492-234 LACING TAPE - WHITE .....161-74492-2001 THERMOFIT SLEEVE, TFE-2X, SIZE 8 .....161-74492-2002 THERMOFIT SLEEVE, INNER DIA 0.093 IN. .....161-74492-2004 THERMOFIT SLEEVE, INNER DIA 0.375 IN. .....161-74492-2005 THERMOFIT SLEEVE, INNER DIA 0.5 IN. .....161-74492-2006 THERMOFIT SLEEVE, INNER DIA 0.25 IN. .....161-74492-2007 SHIELD BRAID, INNER DIA. 0.125 IN. .....161-74492-2008 SHIELD BRAID, INNER DIA. 0.25 IN. .....161-74492-2009 LACING TAPE - WHITE .....161-74492-2010 THERMOFIT SLEEVE - TFE-4X - 0.25 IN. I.D. .....161-74492-2011 THERMOFIT SLEEVE - TFE-4X - 0.375 IN. I.D. .....161-74492-2012 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 45 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 46 ALL Kit 61-74492 NotesExisting Part Number NameQtyNew Part Number -133-132W-132-131W-131-1 THERMOFIT SLEEVE - TFE-2X - SIZE 8 .....161-74492-2013 THERMOFIT SLEEVE - YEL- LOW - 0.375 IN. I.D. .....161-74492-2015 THERMOFIT SLEEVE - TFE-2X - SIZE 10 .....161-74492-2016 THERMOFIT SLEEVE - TFE-2X - SIZE 10 .....161-74492-2017 SPLICE I.D. SLEEVE - SP792 ....1.61-74492-10101 SPLICE I.D. SLEEVE - SP794 ....1.61-74492-10102 SPLICE I.D. SLEEVE - SP796 ....1.61-74492-10103 WIRE I.D. SLEEVE - W0512- 405R,6B,7Y,8G-18 ....1.61-74492-10104 SPLICE I.D. SLEEVE - SP878 ..1...61-74492-10201 SPLICE I.D. SLEEVE - SP880 ..1...61-74492-10202 SPLICE I.D. SLEEVE - SP882 ..1...61-74492-10203 WIRE I.D. SLEEVE - W0514- 405R,6B,7Y,8G-18 ..1...61-74492-10204 SPLICE I.D. SLEEVE - SP884 1.....61-74492-10301 SPLICE I.D. SLEEVE - SP886 1.....61-74492-10302 SPLICE I.D. SLEEVE - SP888 1.....61-74492-10303 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 46 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 47 ALL Kit 61-74492 NotesExisting Part Number NameQtyNew Part Number -133-132W-132-131W-131-1 WIRE I.D. SLEEVE - W0516- 405R,6B,7Y,8G-18 1.....61-74492-10304 CONTACT, SOCK- ET, SIZE 16 5.5.5.BACC47CP2S SLEEVE2.2.2.BACS13S165B SLEEVE2.2.2.BACS13S175B SLEEVE2.2.2.BACS13S187B SLEEVE2.2.2.BACS13S232C (b)SLEEVE2.2.2.BACS13S261C SLEEVE2.2.2.BACS13S275C SLEEVE2.2.2.BACS13S287C TERMINAL, LUG2.2.2.BACT12AC3 SLEEVE, HEAT SHRINK 10.10.10.BACT63D1 SLEEVE, HEAT SHRINK 10.10.10.BACT63D2 WIRE.1.1..BMS13- 48T10C01G020 (a)SPLICE4.4.4.D-436-37 (a) There are more parts than are necessary. (b) Optional part number BACS13S281C. ALL Kit 61-74492 NotesExisting Part Number NameQtyNew Part Number -233W-232W-231W-134W-134-133W WIRE LIST.....-61-74492-133W ASSY - W520....-.61-74492-134 WIRE LIST...-..61-74492-134W WIRE LIST..-...61-74492-231W WIRE LIST.-....61-74492-232W Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 47 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 48 ALL Kit 61-74492 NotesExisting Part Number NameQtyNew Part Number -233W-232W-231W-134W-134-133W WIRE LIST-.....61-74492-233W TERMINAL....2.322320 ASSY - W520 - PARTIAL PREFAB OF WIRING ....1.61-74492-134A SPLICE I.D. SLEEVE - SP804 ....1.61-74492-10401 SPLICE I.D. SLEEVE - SP806 ....1.61-74492-10402 SPLICE I.D. SLEEVE - SP808 ....1.61-74492-10403 WIRE I.D. SLEEVE - W0520- 405R,6B,7Y,8G-18 ....1.61-74492-10404 CONTACT, SOCK- ET, SIZE 16 ....5.BACC47CP2S SLEEVE....2.BACS13S165B SLEEVE....2.BACS13S175B SLEEVE....2.BACS13S187B SLEEVE....2.BACS13S232C (b)SLEEVE....2.BACS13S261C SLEEVE....2.BACS13S275C SLEEVE....2.BACS13S287C TERMINAL, LUG....2.BACT12AC3 SLEEVE, HEAT SHRINK ....10.BACT63D1 SLEEVE, HEAT SHRINK ....10.BACT63D2 WIRE111...BMS13- 48T10C01G018 WIRE...1.1BMS13- 48T10C01G020 Wire111...BMS13- 60T10C01G018 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 48 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 49 ALL Kit 61-74492 NotesExisting Part Number NameQtyNew Part Number -233W-232W-231W-134W-134-133W (a)SPLICE....4.D-436-37 (a) There are more parts than are necessary. (b) Optional part number BACS13S281C. ALL Kit 61-74492 NotesExisting Part Number NameQtyNew Part Number -234W WIRE LIST-61-74492-234W WIRE1BMS13- 48T10C01G018 Wire1BMS13- 60T10C01G018 Group 1-2: Kit 65C38810 NotesExisting Part Number NameQtyNew Part Number -2-1 KIT INSTL - GROUNDING BRACKET, BOOST PUMP WIRING .-65C38810-1 KIT INSTL - GROUNDING BRACKET, BOOST PUMP WIRING -.65C38810-2 INSTALLATION ADAPTER FOR LINER ASSEMBLY 1121A00355-1 (04999A025017 optional) CONVOLUTED LINER 2223A03595-1 CONVOLUTED LINER 2223A03595-3 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 49 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 50 Group 1-2: Kit 65C38810 NotesExisting Part Number NameQtyNew Part Number -2-1 KIT - ELECTRICAL BRACKET, NITRO- GEN GENERA- TION SYSTEM 2265C38706-2 TAPE, ID1165C38810-3 TAPE, ID1165C38810-4 TAPE, ID1165C38810-5 TAPE, ID1165C38810-6 TAPE, ID1165C38810-7 TAPE, ID1165C38810-8 TAPE2265C38810-9 CLAMP, WIRE BUNDLE 44BACC10GU104 CLAMP, WIRE BUNDLE 44BACC10GU114 NUT22BACN10YR3CD (a)RIVET, UNIVER- SAL HD 66BACR15BB6D4C (a)BOLT22BACS12HN3-7 (a)BOLT44BACS12HN3-8 (a)BOLT88BACS12HN3-9 SPACER88BACS18AY3 SPACER88BACS18AY5 SEAL1212BACS45A13 WASHER66NAS1149D0316H (a) If grip length shown is not available at Boeing, fasteners supplied in kits may be one grip length longer than indicated. Also, if any fasteners part numbers listed are not available or have been superseded, substitute fasteners may be supplied in kits. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 50 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 51 ALL Kit 65C38811 NotesExisting Part Number NameQtyNew Part Number -1 KIT-INSTL, CON- DUIT TERMINAL SHIELD -65C38811-1 (a) (b)BOLT-SHOULDER46-84527-1 (a)BOLT4BACB30LM4-10 (c)WASHER, FLAT8NAS1149D0416H (a) If grip length shown is not available at Boeing, fasteners supplied in kits may be one grip length longer than indicated. Also, if any fasteners part numbers listed are not available or have been superseded, substitute fasteners may be supplied in kits. (b) There are more parts than necessary. (c) Optional part number NAS1149D0463H. Group 1: The parts that follow are only necessary for the replacement of the existing fuel tank conduit(s). Kit 65-46509 NotesExisting Part Number NameQTYNew Part Number -166-165-164-163-158-157 (a) (b) (c) TUBE ASSY.....-65-46509-157 (a) (b)TUBE ASSY....-.65-46509-158 (a) (b)TUBE ASSY...-..65-46509-163 (a) (b)TUBE ASSY..-...65-46509-164 (a) (b) (c) TUBE ASSY.-....65-46509-165 (a) (b) (c) CONDUIT ASSY-.....65-46509-166 COUPLING, NUT..222.BACN10CS08D COUPLING, NUT22...2BACN10CS8D SLEEVE, FLARELESS222222BACS13BX08HP WW-T-700/6 6061 T6 TUBING ..111.MR576N (a) Discard the existing part. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 51 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 52 Group 1: The parts that follow are only necessary for the replacement of the existing fuel tank conduit(s). Kit 65-46509 NotesExisting Part Number NameQTYNew Part Number -166-165-164-163-158-157 (b) This part is not used for Production. (c) Use seamless aluminum tubing WW-T-700/6 6061-T6 to assemble the identified Tube Assembly. Group 2: The parts that follow are only necessary for the replacement of the existing fuel tank conduit(s). Kit 65C26901 NotesExisting Part Number NameQTYNew Part Number -91-88-49-48-47-38 (a) (b)TUBE ASSY-ELECTRI- CAL CONDUIT, BOOST PUMP .....-65C26901-38 (a) (b)TUBE ASSY-ELECTRI- CAL CONDUIT, BOOST PUMP ....-.65C26901-47 (a) (b)TUBE ASSY-ELECTRI- CAL CONDUIT, BOOST PUMP ...-..65C26901-48 (a) (b)TUBE ASSY-ELECTRI- CAL CONDUIT, BOOST PUMP ..-...65C26901-49 (a) (b)TUBE ASSY-ELECTRI- CAL CONDUIT, BOOST PUMP .-....65C26901-88 (a) (b) (c) TUBE ASSY--.....65C26901-91 COUPLING, NUT222222BACN10CS08D SLEEVE, FLARELESS222222BACS13BX08HP ALUMINUM ALLOY TUBING; SEE RM PL FOR COMPLETE DE- SCRIPTION .11111MR674X (a) Discard the existing part. (b) This part is not used for Production. (c) Use seamless aluminum tubing WW-T-700/6 6061-T6 to assemble the identified Tube Assembly. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 52 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 53 2. Parts and Materials Supplied by the Operator NotesNameQTYPart Number / Specifi- cation CHEMICAL CONVERSION COATING1 PTBAC5719, TYPE II, CLASS A (a)SEALANT24 OuncesBMS5-37 (a)SEALANT24 OuncesBMS5-45, CLASS B (a)SEALANT24 OuncesBMS5-95 (a)PRIMER24 OuncesBMS 10-11, TYPE I (a)ABSORBENT WIPERS FOR PRO- CESS CLEANING 12 OuncesBMS15-5 BEARING GREASE, LIGHT OR MEDI- UM 24 OuncesDOW CORNING MOLYKOTE 33 THREAD LOCKING COMPOUND12 OuncesLOCTITE 222 LOCKWIRE10 FeetMS20995NC20 ADHESIVE TAPE, WIDTH 0.5 IN1 RollSCOTCH 63 (b) (c)SEAMLESS ALUMINUM TUBING100 inchesWW-T-700/6 6061-T6 Used as mold for vapor seal and pressure seal. PAPER TAPE1 Roll- Length 120 inches.PULL WIRE, #16 OR #18 GAGE4- (a)Lacing Tape - White1 RollBMS13-54, Type III, Class 1, Finish C TERMINAL, LUG4BACT12AC8 (a) (d)SPLICE - SEALING SLEEVE8D-436-59 (a) See the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier data. (b) Use 0.5 inch outer diameter X 0.028 inch wall thickness with finish MIL-C-5541, Class 3. (c) Use to assemble Tube Assembly part number 65-46509-157, 65-46509-165, 65-46509-166, 65C26901- 91, or 65C26901-135. (d) There are more parts than are necessary. 3. Parts Modified and Reidentified None. 4. Parts Removed and Not Replaced None. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 53 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 54 D. Parts Necessary to Change Spares None. E. Special Tooling - Price and Availability None. F. Special Tooling Necessary to do this Service Bulletin No special tools or equipment are necessary to do the change in this service bulletin. But, maintenance and overhaul tools in the manuals given in Paragraph 1.J., References, can be necessary. Examine operator tool supply to make sure all necessary tools are available. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 54 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 55 3. ACCOMPLISHMENT INSTRUCTIONS A. GENERAL INFORMATION CAUTION: KEEP THE WORK AREA, WIRES AND ELECTRICAL BUNDLES CLEAN OF METAL PARTICLES OR CONTAMINATION WHEN YOU USE TOOLS. UNWANTED MATERIAL, METAL PARTICLES OR CONTAMINATION CAUGHT IN WIRE BUNDLES CAN CAUSE DAMAGE TO THE BUNDLES. DAMAGED WIRE BUNDLES CAN CAUSE SPARKS OR OTHER ELECTRICAL DAMAGE. NOTE: 1. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for definition of the acronyms. 2. Obey all of the warnings and cautions given in the specified manual sections. 3. Unless shown differently, these dimensions and tolerances are used: – Linear dimensions are in inches – Tolerance on linear dimensions, other than rivet and bolt edge margins, is plus or minus 0.03 inch – Tolerance on rivet and bolt edge margin is plus or minus 0.05 inch – Angular tolerance is plus or minus 2 degrees – Hole dimensions for standard solid rivets and fasteners are in Structural Repair Manual (SRM) Chapter 51 – Torque 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 Aircraft Maintenance Manual (AMM). — Values for electrical maintenance tasks are included in Chapter 20 of Standard Wiring Practices Manual (SWPM). — Values for engine maintenance tasks are included in Chapter 70 of 737 Aircraft Maintenance Manual (AMM). — Non-standard torque values for maintenance tasks are included in the applicable installation step. 4. Use the approved fastener, process and material substitutions in accordance with SRM Chapter 51. 5. Refer to the SWPM 20-10-11 and SWPM 20-10-12 for the wire installation procedures, and SWPM 20-10-19 for the wire separation requirements, as accepted procedures. 6. The necessary conditions for selection of clamp type and size are included in SWPM 20-10-12. If any wire bundle support clamp specified in this service bulletin does not make a correct fit on the wire bundle, refer to SWPM 20-10-12 as an accepted procedure to select a clamp that fits correctly. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 55 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 56 7. 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. 8. These work instructions refer to procedures included in other Boeing documents. When the words "refer to" are used and the operator has an accepted alternative procedure, the accepted alternative procedure can be used. When the words "in accordance with" are included in the instruction, the procedure in the Boeing document must be used. 9. Refer to Appendix A for a general schematic overview of the scope of work for a Shielded Wire Installation for a typical fuel boost pump. 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. If shading is used, shaded areas in Figures are to separate the non-critical and non-authoritative information from the critical and authoritative information. 15. 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. 16. The compliance times for the actions in Paragraph 3.B., WORK INSTRUCTIONS are in Paragraph 1.E., Compliance. 17. The CONDITIONS, ACTIONS and OPTIONS shown apply to each wing fuel tank conduit independently. 18. Some steps in the Work Instructions are labeled as Required for Compliance (RC). If this service bulletin is mandated by an Airworthiness Directive (AD), then the steps labeled as RC, including sub-steps under an RC step and any figures identified in an RC step, must be done to comply with the AD. If a step or sub-step is labeled "RC Exempt," then the RC requirement is removed from that step or sub-step. An Alternative Method of Compliance (AMOC) is required for any deviations to RC steps, Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 56 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 57 including sub-steps and identified figures. Steps not labeled as RC may be deviated from using accepted methods in accordance with the operator's maintenance or inspection program without obtaining approval of an AMOC. This is provided that the RC steps, including sub-steps and identified figures, can still be done as specified, and the airplane can be put back in an airworthy condition. B. WORK INSTRUCTIONS Group 1: 1. Set the switches for the fuel boost pumps on the pilot’s overhead P5 panel to the OFF position. NOTE: The fuel boost pump that is on the front spar of each wing is not part of this service bulletin. 2. Open the circuit breakers that follow and attach "DO-NOT-CLOSE" tags: NUMBERNAMEPANEL / LOCATION C828TANK 2 AFT BOOST PUMPP6-3 / C3 C361FUEL CROSSFEED VLVP6-3 / C5 C826TANK 1 AFT BOOST PUMPP6-3 / C7 C360ENG 2 FUEL SOVP6-3 / D3 C846CTR TANK R BOOST PUMPP6-3 / D5 C359ENG 1 FUEL SOVP6-3 / D7 C64FUEL CONT FWD 2, AFT 1, CTR LP6-3 / E3 C845CTR TANK L BOOST PUMPP6-3 / E5 C65FUEL CONT FWD 1, AFT 2, CTR RP6-3 / E7 WARNING: PRESSURIZING HYDRAULIC SYSTEMS FOR OPERATION OF THE LEADING EDGE FLAPS AND SLATS ALSO PERMITS OPERATION OF THE TRAILING EDGE FLAPS AND GROUND SPOILERS SIMPLY BY MOVING THE RESPECTIVE CONTROLS. OTHER FLIGHT CONTROL SYSTEMS MAY BE ISOLATED BY SHUTOFF VALVES. ISOLATE OR TAG ALL FLIGHT CONTROL SYSTEMS NOT BEING TESTED AND ENSURE THAT PERSONNEL AND EQUIPMENT ARE CLEAR OF CONTROL SURFACES BEFORE APPLYING HYDRAULIC POWER. WARNING: INSTALL LEADING EDGE FLAP AND SLAT LOCKS TO PREVENT ACCIDENTAL OPERATION OF LEADING EDGE FLAPS AND SLATS. FLAPS AND SLATS ARE FAST ACTING AND CAN CAUSE SERIOUS INJURY TO PERSONNEL. 3. Extend the leading edge slats and install locks. Refer to 737-100/200 AMM 27-81-00 as an accepted procedure. 4. Remove the left wing-to-body fairing panel 3378L and right wing-to-body fairing panel 3478R. Refer to 737-100/200 AMM 12-31-21 for panel locations. 5. Remove the left front spar access panel 6302L and right front spar access panel 6402R. Refer to 737-100/200 AMM 12-31-71 for panel locations. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 57 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 58 6. Remove the panels that follow for access to the aft tank fuel boost pumps. Refer to 737-100/200 AMM 12-31-61 for panel locations and 737-100/200 AMM 57-30-11 as an accepted procedure. a. Panel 7203 (Tank No. 1, aft fuel boost pump). b. Panel 7403 (Tank No. 2, aft fuel boost pump). 7. Remove the panels that follow for access to the center tank fuel boost pumps. Refer to 737-100/200 AMM 12-31-61 for panel locations and 737-100/200 AMM 57-30-11 as an accepted procedure. a. Panel 7201 (Center tank, left fuel boost pump). b. Panel 7401 (Center tank, right fuel boost pump). 8. Open the forward cargo door to get access to the forward cargo compartment. Refer to 737-100/200 AMM 52-31-00 as an accepted procedure. 9. In the forward cargo compartment between station 500A and station 520, remove and keep the left aft bulkhead lining panels and right aft bulkhead lining panels. Refer to 737-100/200 AMM 25-52-131 as an accepted procedure. 10. In the forward cargo compartment, remove and keep the left mixing chamber and right mixing chamber. Refer to 737-100/200 AMM 21-21-00 as an accepted procedure. 11. In the forward cargo compartment between station 500A and station 520, remove and keep the right ceiling lining. Refer to 737-100/200 AMM 25-52-111 as an accepted procedure. 12. RC - Install new grounding bracket at station 520 on the left side of the forward cargo compartment in accordance with FIGURE 1. 13. RC - Install new grounding bracket at station 520 on the right side of the forward cargo compartment in accordance with FIGURE 3. 14. RC - Remove wire bundle W512 and Teflon sleeve, if Teflon sleeve is installed, from between the No.1 tank aft fuel boost pump and left wing front spar area in accordance with FIGURE 5 and FIGURE 6 . 15. RC - Remove wire bundle W514 and Teflon sleeve, if Teflon sleeve is installed, from between the left center tank fuel boost pump and the left wing front spar area in accordance with FIGURE 5 and FIGURE 7 . 16. RC - Do one of the three options that follow to find leaks in the left wing fuel tank conduits: a. OPTION 1: (1) Fill the applicable fuel tank with fuel to full, covering the conduit. (2) After a minimum of 5 minutes, make sure there are no signs of fuel leakage at the ends of the electrical conduit. (3) Examine the end of the electrical conduit at the front spar and the end near the fuel boost pump for indications of fuel leakage. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 58 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 59 b. OPTION 2: (1) Fill the applicable fuel tank with fuel to full, covering the conduit. (2) Pull a clean cotton wiper (BMS 15-5) through the fuel tank conduit with lacing tape. NOTE: Tie a second lacing tape to the cotton wiper so that you will have lacing tape available to pull the electrical wire through the conduit. (3) Make sure there is no fuel on the cotton wiper (BMS 15-5). c. OPTION 3: NOTE: This test can be done with any quantity of fuel in the tank. (1) Use fittings to plug one end of the fuel tank conduit and to connect a pressure gage and air supply to the other end of the fuel tank conduit. NOTE: A pressure gage must be connected so it reads the pressure in the fuel tank conduit when the air supply is shut off. (2) Pressurize the fuel tank conduit to 20 psi (+/- 2 psi) and shut off the air supply. (3) After a minimum of 5 minutes with no supply of air, make sure the pressure shown on the pressure gage does not decrease. CONDITION 1 - LEAK FOUND a. If a leak is found, repair or replace the fuel tank conduit in accordance with Step 17. CONDITION 2 - NO LEAK IS FOUND a. If no leak is found it is not necessary to repair or replace the fuel tank conduit. Go to Step 18. 17. Repair fuel tank conduit leaks. NOTE: The left wing No. 1 tank fuel tank conduit is two assemblies joined together with a union. 1. 2. The left wing center tank fuel tank conduit is a single assembly. a. Defuel and purge the fuel tank. Refer to 737-100/200 AMM 28-10-00 and 737-100/200 AMM 28-23-00 as accepted procedures. b. Remove the fuel tank access panel 7202L for the left wing fuel tank. Refer to 737-100/200 AMM 12-31-61 as an accepted procedure. c. RC - Test for leaks in the fuel tank conduit in accordance with Step 16, Option 3. CONDITION 1 - LEAK FOUND AT FUEL TANK CONDUIT B-NUTS - TIGHTEN FUEL TANK CONDUIT B-NUTS a. Remove sealant. Refer to SOPM 20-50-19 as an accepted procedure. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 59 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT ### Page 60 b. Remove lockwire. Refer to SOPM 20-50-02 as an accepted procedure. c. Torque the B-nuts to 266 - 294 inch-pounds. Refer to SOPM 20-50-00 as an accepted procedure. d. Install lockwire. Refer to SOPM 20-50-02 as an accepted procedure. e. Apply BMS5-45 sealant. Refer to SOPM 20-50-19 as an accepted procedure. f. RC - Check for leaks in the fuel tank conduit in accordance with Step 16, Option 3. CONDITION 2 - LEAK FOUND IN LEFT WING NO. 1 FUEL TANK CONDUIT - REPLACE CONDUIT a. RC - If the leak is in the left wing No. 1 tank fuel tank conduit replace the conduit in accordance with FIGURE 8 . b. RC - Check for leaks in the fuel tank conduit in accordance with Step 16, Option 3. CONDITION 3 - LEAK FOUND IN LEFT WING CENTER TANK FUEL TANK - REPLACE CONDUIT a. RC - If the leak is in the left wing center tank fuel tank conduit replace the conduit in accordance with FIGURE 10 . b. RC - Check for leaks in the fuel tank conduit in accordance with Step 16, Option 3. 18. Internally clean the left wing fuel boost pump conduits. Use compressed air (20 psi maximum) to blow out any contamination or pull a wiper through the conduits with lacing tape. 19. RC - Remove or stow No. 1 tank aft fuel boost pump wire bundle W512 in accordance with FIGURE 12 and FIGURE 13 . 20. RC - Remove or stow left center tank fuel boost pump wire bundle W514 in accordance with FIGURE 12 and FIGURE 14 . 21. RC - Install new convoluted liners, new wire bundle W512, and new wire bundle W514 in the fuel tank conduits between the applicable fuel boost pump housing and left wing front spar in accordance with FIGURE 15 . 22. RC - Route new wire bundle W512 and new wire bundle W514 in accordance with FIGURE 16 . 23. RC - Change ground wire to the No. 1 tank aft fuel boost pump in accordance with FIGURE 17 and make the changes to wire bundle W512 in accordance with FIGURE 18 . 24. RC - Change ground wire to the left center fuel boost pump in accordance with FIGURE 19 and make the changes to wire bundle W514 in accordance with FIGURE 20. 25. RC - Install the left ground stud assembly at station 520 for wire bundle W512 and wire bundle W514 in accordance with FIGURE 21 . Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 23, 2014 737-28A1273Revision 1: March 14, 2017 60 of 234 BOEING SERVICE BULLETIN 737-28A1273 ALERTALERT The text continues at https://openairdocs.org/service-documents/boeing/737-28a1273/file/8bf6ca38082c.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.