# Boeing Alert Service Bulletin 737-57A1304: Revision 1 - Rights: © The Boeing Company. Filed by the FAA in regulations.gov docket FAA-2009-1026; AD 2009-23-10 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. - Document: [Boeing Alert Service Bulletin 737-57A1304](https://openairdocs.org/service-documents/boeing/737-57a1304.md) - Title as filed: U.S. DOT/FAA - Boeing Service Bulletin - Pages: 37 - PDF: https://openairdocs.org/files/sha256/87/1c/871cc0f893e7b112710ac2ac15fc087428ab6f80a49b7cfd997480be90280368 - Page: https://openairdocs.org/service-documents/boeing/737-57a1304/file/871cc0f893e7 ## 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 Number: 737-57A1304 Original Issue: June 02, 2008 Revision 1: August 11, 2009 ATA System: 5752 SUBJECT: Wings - Trailing Edge Flaps - Outboard Flap, Carriage Spindle- Inspection for Corrosion Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15 CFR 730-774). An export license may be required before it is used for development, production or use by foreign persons from specific countries. The controller of this data has the individual responsibility to abide by all export laws. 9E991ECCN: BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET Copyright © 2008 The Boeing Company Unpublished Work - All Rights Reserved Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable subject matter. Boeing also claims copyright in this document as a compilation and/or collective work. This document includes proprietary information owned by The Boeing Company and/or one or more third parties. Treatment of the document and the information it contains is governed by contract with Boeing. For more information, contact The Boeing Company, P.O. Box 3707, Seattle, Washington 98124. Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, Dreamliner, BBJ, DC-8, DC-9, DC-10, KC-10, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8A, Poseidon and the Boeing livery are all trademarks owned by The Boeing Company; and no trademark license is granted in connection with this document unless provided in writing by Boeing. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 1 of 37 7.0 ### Page 2 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 2 of 37 BOEING SERVICE BULLETIN 737-57A1304 BLANK PAGE ### Page 3 Table of Contents Revision Transmittal Sheet ............................................ 5 Summary ...................................................... 7 1. PLANNING INFORMATION ........................................ 1 1 A. Effectivity ............................................... 1 1 1. Airplanes ............................................ 1 1 2. Spares Affected ........................................ 1 7 B. Concurrent Requirements ...................................... 1 7 C. Reason ................................................ 1 7 D. Description .............................................. 1 8 E. Compliance .............................................. 1 9 F. Approval ............................................... 2 2 G. Manpower .............................................. 2 2 H. Weight and Balance Changes .................................... 2 3 I. Electrical Load Data ......................................... 2 3 J. References .............................................. 2 3 1. Existing Data .......................................... 2 3 2. Data supplied with this Service Bulletin ............................ 2 3 3. Installation Drawings Used in the Preparation of this Service Bulletin ............ 2 3 K. Publications Affected ........................................ 2 4 L. Interchangeability and Intermixability of Parts ........................... 2 4 2. MATERIAL INFORMATION ........................................ 2 5 A. Material - Price and Availability ................................... 2 5 B. Industry Support Information .................................... 2 5 C. Parts Necessary For Each Airplane ................................. 2 5 1. Kits/Parts ............................................ 2 5 2. Parts and Materials Supplied by the Operator ........................ 2 5 3. Parts Modified and Reidentified ................................ 2 5 4. Parts Removed and Not Replaced .............................. 2 5 D. Parts Necessary to Change Spares ................................. 2 5 E. Special Tooling - Price and Availability ............................... 2 5 F. Special Tooling Necessary to do this Service Bulletin ....................... 2 6 3. ACCOMPLISHMENT INSTRUCTIONS .................................. 2 7 A. GENERAL INFORMATION ..................................... 2 7 B. WORK INSTRUCTIONS ....................................... 2 8 FIGURE 1: LOCATE PART NUMBER FOR CARRIAGES AT WBL 254 AND WBL 355 WITH HVOF THERMAL COATED SPINDLES ............................... 3 1 FIGURE 2: INSPECT CARRIAGES SPINDLES WITH HVOF THERMAL COATING FOR CORROSION [Group 1, Configuration 2] ................................... 3 3 APPENDIX A: SERIAL NUMBERS OF SUSPECT CARRIAGE SUB-ASSEMBLIES 65C27409-29 AND -31. .................................................. 3 5 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 3 of 37 BOEING SERVICE BULLETIN 737-57A1304 ### Page 4 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 4 of 37 BOEING SERVICE BULLETIN 737-57A1304 BLANK PAGE ### Page 5 Commercial Airplanes 737 Service Bulletin Revision Transmittal SheetNumber: 737-57A1304Original Issue: June 02, 2008 Revision 1: August 11, 2009 ATA System: 5752 SUBJECT: Wings - Trailing Edge Flaps - Outboard Flap, Carriage Spindle- Inspection for Corrosion This revision includes all pages of the service bulletin. COMPLIANCE INFORMATION RELATED TO THIS REVISION Federal Aviation Administration (FAA) Airworthiness Directive 2008-15-05, is related to this service bulletin. No more work is necessary on airplanes changed as shown in the original issue of this service bulletin. REASON FOR REVISION This revision is sent to add the warranty statement and update Appendix A by deleting table 1 and revising table 2. These sections were changed: – In the Background and Reason section the service history was updated to include 13 additional reports. – Throughout the Service bulletin, the terminating action has been expanded to include refurbished carriages that have a serial number with a R suffix or carriages that do not have a HVOF coating. – The FAA Airworthiness Directive 2008-15-05 has been added to the Compliance sections and the AMOC statement was added to the Approval section. – The Industry Support Information on the Summary page and Paragraph 2.B., Industry Support Information; the warranty statement has been added. – Paragraph 1.A.1. Airplanes, in the description for configuration 2; the word "suspect" was added prior to carriages. – Paragraph 1.K. Publication Affected was updated to add the damage tolerance statement. – In APPENDIX A Table 1 serial numbers were deleted and Table 2 was revised to reduce the serial number ranges showing each suspect serial number. A note was added saying serial numbers with a R suffix are not suspect. – In APPENDIX A, Table 3 has been added to include additional serial numbers that were removed by AMOC letter 120S-08-854. Vertical lines are put on the left edge of each page, except in Paragraph 1.A., Effectivity, to show the location of important changes. Pages with no vertical lines have no important changes. REVISION HISTORY June 02, 2008Original Issue: BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 5 of 37 ### Page 6 August 11, 2009Revision 1: BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 6 of 37 BOEING SERVICE BULLETIN 737-57A1304 ### Page 7 Commercial Airplanes 737 Service Bulletin SummaryNumber: 737-57A1304Original Issue: June 02, 2008 Revision 1: August 11, 2009 ATA System: 5752 SUBJECT: Wings - Trailing Edge Flaps - Outboard Flap, Carriage Spindle- Inspection for Corrosion CONCURRENT REQUIREMENTS None. BACKGROUND This service bulletin provides instruction to inspect 737-300/400/500 carriage spindles with High Velocity Oxy-Fuel (HVOF) thermal coating that are installed at WBL 254 and WBL 355 on the outboard trailing edge flaps for corrosion. These carriages would have been installed during an overhaul or replacement that would have been conducted after February 2006. If the corrosion goes undetected it could lead to a fracture of the carriage spindle. One fractured carriage spindle can be compensated for by the pilot with inputs to the aileron and or rudder. However fractures of both the inboard and the outboard carriage spindles at the forward end of the spindle through the large diameter (the critical section), on a given outboard flap may preclude continued safe flight and landing of the airplane. Boeing has received initial reports from two operators who have found corrosion on the carriage spindles that are located on the outboard trailing edge flaps. The affected carriages had been overhauled after February 2006 and the carriage sub-assembly had been replaced with a new carriage sub-assembly that had the HVOF thermal coating applied to the spindle. The HVOF thermal coating had flaked off exposing the base metal and allowing corrosion on the spindle. One of the two operators reported finding 8 carriages on 5 airplanes coated with the HVOF thermal coating, which had corrosion on the spindle. The other operator has found 1 carriage with corrosion. Since the initial release of this service bulletin, Boeing has received an additional 13 reports from operators of carriage spindles with corrosion. So far none of the HVOF thermal coated carriages have been reported with fractures. Boeing has examined the parts returned from the operator for evidence of environmental contaminants as well as reviewing the manufacturing process to determine the cause. From review of our records, approximately 500 carriage sub-assemblies with the HVOF thermal coating have been delivered to the fleet for use during overhaul. These carriages were all delivered after February 2006. Boeing has purged all suspect carriages from inventory, and all available spares have properly applied coating. FAA AMOC letter 120S-08-854 removed the Table 1 serial numbers from the inspection requirements. A subsequent discovery of a similar problem with certain serial numbers included in the AMOC necessitates the addition of Table 3 to APPENDIX A. Boeing Service Related Problem (SRP) 737-SRP-57-0221 is related to this service bulletin. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 7 of 37 ### Page 8 ACTION Review your records or inspect for the carriage part number and/or serial number to determine if you have any of the suspect carriage sub-assemblies that have the HVOF thermal coating on the spindle. These carriages would only be on 737-300/400/500 classic airplanes that have inboard (WBL 254) or outboard (WBL 355) flap carriage assemblies that were overhauled or replaced after February 2006. If you determine that you do have suspect carriages with the HVOF thermal coating on the spindle, inspect for corrosion. Do a detailed inspection or a borescope inspection on the forward end of the spindle, that is forward of the flap front spar. Do a detailed inspection on the aft section of the spindle that is exposed when the access panel is removed. Inspect the HVOF thermal coated spindles in accordance with Paragraph 1.E., Compliance. Remove and replace carriages that are corroded with a new or serviceable carriage. Perform a gap check or a NDT ultrasonic inspection if no corrosion is found. If during your inspection you find potential indications of corrosion like flaking metallic particles, disbonded sealant, cracked paint or primer and you are not able to determine if corrosion is present, remove the carriage from the midflap and perform a detailed inspection for corrosion of the entire spindle surface. The replacement of a carriage that has the suspect HVOF thermal coating on the spindle with one that does not have this HVOF coating or one that has been refurbished and the serial number has a R suffix, will terminate the inspection in this service bulletin for that carriage only. If you determine that your airplane does not have any carriage with the HVOF thermal coating, then there is no further action required. EFFECTIVITY 737-300, -400, -500 Airplanes. Refer to Paragraph 1.A.1., Airplanes for the list of affected airplanes. COMPLIANCE Refer to Paragraph 1.E., Compliance. Federal Aviation Administration (FAA) Airworthiness Directive 2008-15-05 is related to this service bulletin. The Federal Aviation Administration (FAA) will possibly release another Airworthiness Directive related to this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin mandatory. INDUSTRY SUPPORT INFORMATION Boeing warranty remedies are available for airplanes in warranty as of April 25, 2008. Please refer to Paragraph 2.B., Industry Support Information. MANPOWER Refer to Paragraph 1.G., Manpower. MATERIAL INFORMATION None. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 8 of 37 BOEING SERVICE BULLETIN 737-57A1304 ### Page 9 (OCR) BOEING SERVICE BULLETIN 737-57A1304 REMOVE ACCESS PANEL SPINDLE BEARING BEARING SUPPORT TRAILING EDGE FLAP CARRIAGE SERIAL NUMBER LOCATION DO A GAP CHECK OF THE CARRIAGE SPINDLE OUTBOARD MIDFLAP CARRIAGE DO A DETAILED INSPECTION FOR CORROSION 360 DEGREES AROUND THE CARRIAGE SPINDLES WITH HOF THERMAL COATING. CARRIAGE PART AS AN OPTION USE A BORESCOPE TO NUMBER AND SERIAL INSPECT 360 DEGREES AROUND THE NUMBER LOCATION SERIAL NUMBER ON PART NUMBER AND FORWARD SECTION OF THE SPINDLE OLDER CARRIAGES 1565392 Original Issue: June 02, 2008 Revision 1: August 11, 2009 Copyright © Unpublished Work - See page 1 for details. BOEING PROPRIETARY - 737-57A1304 9 of 37 ### Page 10 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 10 of 37 BOEING SERVICE BULLETIN 737-57A1304 BLANK PAGE ### Page 11 Commercial Airplanes 737 Service Bulletin Number: 737-57A1304 Original Issue: June 02, 2008 Revision 1: August 11, 2009 ATA System: 5752 SUBJECT: Wings - Trailing Edge Flaps - Outboard Flap, Carriage Spindle- Inspection for Corrosion 1. PLANNING INFORMATION A. Effectivity 1. Airplanes DESCRIPTIONCONFIGURATIONGROUP 737-300, -400, -500 airplanes.-1 737-300, -400, -500 airplanes.1 737-300, -400, -500 airplanes with suspect carriages that have HVOF thermal coating on the spindle. 2 Airplane Models: 737-300, 737-400, 737-500 GroupVariable Number 1PJ301 - PJ302 1PJ551 - PJ561 1PJ601 - PJ615 1PJ811 1PJ816 - PJ817 1PM381 - PM399 1PM401 - PM417 1PM541 - PM564 1PP001 - PP054 1PP101 - PP169 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 11 of 37 ### Page 12 GroupVariable Number 1PP181 - PP199 1PP201 - PP205 1PP221 1PP231 - PP243 1PP281 - PP286 1PP301 - PP305 1PP351 - PP353 1PP376 - PP384 1PP391 - PP393 1PP401 - PP440 1PP471 - PP475 1PP501 - PP522 1PP631 - PP634 1PP651 - PP652 1PP671 - PP699 1PP701 - PP733 1PP771 - PP779 1PP801 - PP808 1PP821 - PP827 1PP831 - PP848 1PP851 - PP852 1PP861 - PP877 1PP891 - PP899 1PP901 - PP936 1PP946 - PP948 1PP951 - PP952 1PP961 - PP967 1PP981 - PP991 1PP993 1PQ001 - PQ016 1PQ026 - PQ041 1PQ051 - PQ092 1PQ101 - PQ199 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 12 of 37 BOEING SERVICE BULLETIN 737-57A1304 ### Page 13 GroupVariable Number 1PQ201 - PQ202 1PQ221 - PQ237 1PQ241 - PQ243 1PQ251 - PQ267 1PQ281 - PQ299 1PQ301 - PQ307 1PQ331 - PQ332 1PQ341 - PQ348 1PQ361 - PQ373 1PQ391 - PQ395 1PQ401 - PQ418 1PQ421 1PQ431 - PQ438 1PQ447 - PQ448 1PQ451 1PQ454 1PQ471 - PQ475 1PQ479 - PQ481 1PQ486 - PQ487 1PQ491 - PQ493 1PQ771 - PQ772 1PQ791 - PQ793 1PQ801 - PQ805 1PQ931 - PQ935 1PQ951 1PQ971 - PQ997 1PR001 - PR017 1PR021 - PR034 1PR041 - PR045 1PR061 - PR072 1PR077 - PR082 1PR091 - PR092 1PR096 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 13 of 37 BOEING SERVICE BULLETIN 737-57A1304 ### Page 14 GroupVariable Number 1PR101 1PR121 - PR122 1PR131 - PR132 1PR141 - PR143 1PR161 - PR172 1PR181 1PS601 - PS631 1PS636 - PS638 1PS641 - PS644 1PS651 - PS657 1PS666 - PS669 1PS691 - PS692 1PS701 - PS706 1PS751 - PS799 1PS811 1PS836 - PS837 1PS841 - PS846 1PS851 - PS852 1PS856 1PS861 - PS863 1PS866 - PS868 1PS871 - PS874 1PS896 - PS897 1PS901 - PS941 1PS956 - PS957 1PS961 - PS963 1PS971 - PS978 1PT001 - PT015 1PT021 - PT031 1PT041 - PT064 1PT101 - PT105 1PT121 - PT138 1PT146 - PT148 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 14 of 37 BOEING SERVICE BULLETIN 737-57A1304 ### Page 15 GroupVariable Number 1PT161 - PT170 1PT181 - PT188 1PT211 - PT220 1PT295 1PT301 - PT309 1PT331 - PT360 1PT381 - PT399 1PT401 - PT438 1PT501 - PT517 1PT561 - PT565 1PT581 - PT586 1PT611 - PT621 1PT641 - PT644 1PT651 - PT656 1PT671 - PT672 1PT681 - PT685 1PT701 - PT703 1PT716 - PT717 1PT721 - PT725 1PT801 - PT834 1PT851 - PT854 1PT871 - PT886 1PT901 - PT930 1PT971 - PT973 1PT981 - PT985 1PT996 1PU001 - PU025 1PU301 1PU311 - PU313 1PV001 - PV055 1PV201 - PV209 1PV226 - PV229 1PV231 - PV237 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 15 of 37 BOEING SERVICE BULLETIN 737-57A1304 ### Page 16 GroupVariable Number 1PV271 - PV272 1PV281 - PV287 1PV296 1PV301 - PV302 1PV351 1PV356 - PV357 1PW001 - PW054 1PW061 - PW068 1PW072 1PW086 - PW088 1PW091 - PW094 1PW101 - PW102 1PW106 1PW111 - PW120 1PW156 - PW157 1PW161 - PW171 1PW201 - PW252 1PW261 - PW268 1PW271 - PW276 1PW278 1PW281 - PW293 1PW296 1PW301 - PW327 1PW401 - PW408 1PW411 - PW418 1PW421 - PW424 1PW431 - PW435 1PW441 - PW450 1PW461 - PW467 1PW501 - PW504 1PW511 - PW522 1PW524 - PW550 1PW556 - PW557 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 16 of 37 BOEING SERVICE BULLETIN 737-57A1304 ### Page 17 GroupVariable Number 1PW561 - PW564 1PW571 - PW576 1PW591 - PW596 1PW611 - PW622 1PW631 - PW637 1PW661 - PW662 1PW681 - PW683 1PW701 - PW702 1PW711 - PW717 1PW741 - PW742 1PW761 1PW771 1PW831 1PW851 - PW856 2. Spares Affected Examine your spares supply for the parts or components identified in this service bulletin. If any parts or components are found, refer to Paragraph 3.B. Work Instruction for the required action 90 days after these parts are installed. B. Concurrent Requirements None. C. Reason This service bulletin provides instruction to inspect 737-300/400/500 carriage spindles with High Velocity Oxy-Fuel (HVOF) thermal coating that are installed at WBL 254 and WBL 355 on the outboard trailing edge flaps for corrosion. These carriages would have been installed during an overhaul or carriage replacement that would have been conducted after February 2006. If the corrosion goes undetected it could lead to a fracture of the carriage spindle. One fractured carriage spindle can be compensated for by the pilot with inputs to the aileron and or rudder. However fractures of both the inboard and the outboard carriage spindles at the forward end of the spindle through the large diameter, ( the critical section) on a given outboard flap may preclude continued safe flight and landing of the airplane. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 17 of 37 BOEING SERVICE BULLETIN 737-57A1304 ### Page 18 Boeing has received initial reports from two operators who have found corrosion on the carriage spindles that are located on the outboard trailing edge flaps. The affected carriages had been overhauled after February 2006 and the carriage sub-assembly had been replaced with a new carriage sub-assembly that had the HVOF thermal coating applied to the spindle. The HVOF thermal coating had flaked off exposing the base metal and allowing corrosion on the spindle. One of the two operators reported finding 8 carriages on 5 airplanes coated with the HVOF thermal coating, which had corrosion on the spindle. The other operator has found 1 carriage with corrosion. Since the initial release of this service bulletin, Boeing has received an additional 13 reports from operators of carriage spindles with corrosion. So far none of the HVOF thermal coated carriages have been reported with fractures. Boeing has examined the parts returned from the operator for evidence of environmental contaminants as well as reviewing the manufacturing process to determine the cause. From review of our records, approximately 500 carriage sub-assemblies with the HVOF thermal coating have been delivered to the fleet for use during overhaul. These carriages were all delivered after February 2006. Boeing has purged all suspect carriages from inventory, and all available spares have properly applied coating. FAA AMOC letter 120S-08-854 removed the Table 1 serial numbers from the inspection requirements. A subsequent discovery of a similar problem with certain serial numbers included in the AMOC necessitates the addition of Table 3 to APPENDIX A. Boeing Service Related Problem (SRP) 737-SRP-57-0221 is related to this service bulletin. D. Description Review your records or inspect for the carriage part number and/or serial number to determine if you have any of the suspect carriage sub-assemblies that have the HVOF thermal coating on the spindle. These carriages would only be on 737-300/400/500 classic airplanes that have inboard (WBL 254) or outboard (WBL 355) flap carriage assemblies that were overhauled or replaced after February 2006. If you determine that you do have suspect carriages with the HVOF thermal coating on the spindle, inspect for corrosion. Do a detailed inspection or a borescope inspection on the forward end of the spindle, that is forward of the flap front spar. Do a detailed inspection on the aft section of the spindle that is exposed when the access panel is removed. Inspect the HVOF thermal coated spindles in accordance with Paragraph 1.E., Compliance. Remove and replace carriages that are corroded with a new or serviceable carriage. Perform a gap check or a NDT ultrasonic inspection if no corrosion is found. If during your inspection you find potential indications of corrosion like flaking metallic particles, disbonded sealant, cracked paint or primer and you are not able to determine if corrosion is present, remove the carriage from the midflap and perform a detailed inspection for corrosion of the entire spindle surface. The replacement of a carriage that has the suspect HVOF thermal coating on the spindle with one that does not have this HVOF coating or one that has been refurbished and the serial number has a R suffix, will terminate the inspection in this service bulletin for that carriage only. If you determine that your airplane does not have any carriage with the HVOF thermal coating, then there is no further action required. No more work is necessary on airplanes changed as shown in the original issue of this service bulletin. Revision 1 is sent to: – In the Background and Reason section the service history was updated to include 13 additional reports. – Throughout the Service bulletin, the terminating action has been expanded to include refurbished carriages that have a serial number with a R suffix or carriages that do not have a HVOF coating. – The FAA Airworthiness Directive 2008-15-05 has been added to the Compliance sections and the AMOC statement was added to the Approval section. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 18 of 37 BOEING SERVICE BULLETIN 737-57A1304 ### Page 19 – The Industry Support Information on the Summary page and Paragraph 2.B., Industry Support Information; the warranty statement has been added. – Paragraph 1.A.1. Airplanes, in the description for configuration 2; the word "suspect" was added prior to carriages. – Paragraph 1.K. Publication Affected was updated to add the damage tolerance statement. – In APPENDIX A Table 1 serial numbers were deleted and Table 2 was revised to reduce the serial number ranges showing each suspect serial number. A note was added saying serial numbers with a R suffix are not suspect. – In APPENDIX A, Table 3 has been added to include additional serial numbers that were removed by AMOC letter 120S-08-854. NOTE: Boeing recommends working service bulletins 737-57A1218 and 737-57A1277 at the same time as this service bulletin based on common access. 1. 2. If corrosion is found, send a copy of the inspection data and the serial number of the carriage. If a camera is available, include a photograph that shows the extent of the corrosion found. Send to: — BOEING COMMERCIAL AIRPLANES GROUP ATTENTION: MANAGER, AIRLINE SUPPORT The work in this service bulletin is done in the maintenance zone(s) given below. Affected Maintenance Zones ZoneModel 307, 407737-300, 737-400, 737-500 E. Compliance Federal Aviation Administration (FAA) Airworthiness Directive 2008-15-05 is related to this service bulletin. The Federal Aviation Administration (FAA) will possibly release another Airworthiness Directive related to this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin mandatory. Table 1: Inspect HVOF thermal coated Outboard Flap, Carriage Spindles at WBL 254 and WBL 355 for Corrosion. Repeat Interval (Not to Exceed) Compliance TimeActionCondition (b)Within 30 days af- ter the initial re- lease date on this service bulletin Determine if you have any suspect carriage in- stalled with the HVOF thermal coated spindle in accordance with Work In- struction, Section 3.B.1. All airplanes BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 19 of 37 BOEING SERVICE BULLETIN 737-57A1304 ### Page 20 Table 1: Inspect HVOF thermal coated Outboard Flap, Carriage Spindles at WBL 254 and WBL 355 for Corrosion. Repeat Interval (Not to Exceed) Compliance TimeActionCondition (b)Within 30 days of the date of revision 01 of this service bulletin. Determine if you have any suspect carriage with a serial number listed in APPENDIX A, Table 2 or 3, in accordance with Work Instruction, Section 3.B.1. All airplanes 90 days. (a) (b)Within 30 days af- ter the initial re- lease date on this service bulletin or 90 days from the installation of a new suspect HVOF thermal coated spindle, whichever occurs later. Do a detail inspection for corrosion on the carriage with HVOF thermal coat- ed spindle in accordance with Work Instruction, Section 3.B.6. Airplanes with the HVOF thermal coated suspect carriage spindles having serial numbers listed in APPENDIX A, Table 2. As an option for the for- ward section, do a borescope inspection for corrosion on the carriage with HVOF thermal coat- ed spindle in accordance with Work Instruction, Section 3.B.6. (a) (b)within 4 years of the release date of revision 1 of this service bulletin. Replace the carriage in accordance with work in- struction, Section 3.B.8 90 days (a) (b)Within 30 days af- ter the date of revi- sion 01 of this ser- vice bulletin or within 90 days of the last inspection required by rev 0 of this service bul- letin, whichever occurs later. Do a detailed inspection for corrosion on the car- riages with APPENDIX A, Table 3 serial numbers in accordance with Work In- struction, Section 3.B.6.b. Airplanes with carriages having serial numbers list- ed in APPENDIX A, Table 3. As an option, do a borescope inspection for corrosion on the carriage with APPENDIX A, Table 3 serial numbers in accor- dance with Work Instruc- tion, Section 3.B.6.b. (a) (b)within 4 years of the release date of revision 1 of this service bulletin. Replace the carriage in accordance with Work In- struction, Section 3.B.8. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 20 of 37 BOEING SERVICE BULLETIN 737-57A1304 ### Page 21 Table 1: Inspect HVOF thermal coated Outboard Flap, Carriage Spindles at WBL 254 and WBL 355 for Corrosion. Repeat Interval (Not to Exceed) Compliance TimeActionCondition (a) (b)Before further flight. Replace the carriage in accordance with Work In- struction, Section 3.B.8. If corrosion is found on a carriage listed in either Ta- ble 2 or 3. -Before further flightDo a detailed inspection for corrosion on the entire spindle surface in accor- dance with Work Instruc- tion, Section 3.B.6. If only potential indications are found on carriages list- ed in either Table 2 or 3. 15 days or 150 flight cycles whichever occurs later. (a) (b) Before further flight. Perform a gap check on Midflaps that have car- riage with HVOF thermal coated spindle in accor- dance with service bul- letin 737-57A1277 Work Instruction 3.B Work Package 2 - Midflap / Spindle Carriage Gap Check. If no corrosion is found on a carriage listed in either Table 2 or 3. As an option do a NDT ultrasonic inspection in accordance with service bulletin 737-57A1277 Work Instruction 3.B Work Package 1 - On Wing NDT Ultrasonic & General Visual Inspec- tion. (a) (b)Before further flight. Replace the carriage in accordance with Work In- struction, Section 3.B.8. If a severed spindle is indi- cated. (a) (b)-As an option replace the suspect carriage spindle with a non-suspect car- riage spindle. Airplanes with the HVOF thermal coated suspect carriage spindles having serial numbers listed in APPENDIX A, Table 2 or 3. (a) Replacement of a HVOF thermal coated carriage spindle with a carriage that is not coated with HVOF will provide terminating action for the inspections in this service bulletin for that carriage spindle only. (b) Refurbishment of suspect HVOF carriage spindles will provide terminating action for the inspections in this service bulletin for that carriage spindle only. (A Refurbished carriage spindle is indicated by the R suffix that follows the serial number.) Refer to Multi-Operator Message (MOM) MOM-MOM-09-0191-01B for information on the carriage spindle refurbishment program.. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 21 of 37 BOEING SERVICE BULLETIN 737-57A1304 ### Page 22 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. This service bulletin has been approved by the FAA. In addition, the Manager of the FAA Seattle Aircraft Certification Office approves the accomplishment of the repetitive inspections, and investigative and corrective actions defined in paragraph 3.B., Work Instruction of Revision 1 of this SB as an alternative method of compliance (AMOC) to the repetitive inspections, and investigative and corrective actions specified in the initial revision to this service bulletin and required by paragraphs (g), (h) and (i) of AD 2008-15-05. All provisions of AD 2008-15-05 that are not specifically referenced in the preceding sentence remain in effect and must be complied with. The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to revision 1 of this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin revision mandatory. 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 This estimate does not include the task hour data given in the service bulletins in Paragraph 1.B., Concurrent Requirements. The table below shows an estimate of the task hours necessary to do this service bulletin for each carriage spindle. 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. Elapsed HoursTask HoursNumber of Per- sons Task 0.600.601Open Access 1.251.251Inspect 4.2517.004Replace 0.600.601Close Access BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 22 of 37 BOEING SERVICE BULLETIN 737-57A1304 ### Page 23 Elapsed HoursTask HoursNumber of Per- sons Task 0.751.502Test 7.4520.95TOTAL FOR EACH AIRPLANE CAR- RIAGE SPINDLE H. Weight and Balance Changes None. I. Electrical Load Data Not applicable. J. References 1. Existing Data a. Service Related Problem (SRP) 737-SRP-57-0221 b. Boeing Service Bulletin 737-57A1277 c. Boeing Parts Standards Document D-590 d. Boeing Drawing 65-88700 e. 737-300/400/500 Aircraft Maintenance Manual (AMM) 27-51-00, 27-51-34, 27-51-44 f. Standard Overhaul Practices Manual (SOPM) SOPM 20-50-10 g. Multi-Operator Message (MOM) MOM-MOM-09-0191-01B h. Federal Aviation Administration (FAA) AD 2008-15-05 i. FAA AMOC letter 120S-08-854 j. Boeing Service Bulletin 737-57A1218 2. Data supplied with this Service Bulletin None. 3. Installation Drawings Used in the Preparation of this Service Bulletin TitleDrawing Number Trailing Edge Flap Installation and Rigging Procedures65C16930 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 23 of 37 BOEING SERVICE BULLETIN 737-57A1304 ### Page 24 TitleDrawing Number Carriage Sub Assy - Outboard Flap65C27409 Carriage Assy, Outboard Flap, Wing65-46481 These drawings were used to prepare this service bulletin. These drawings are not necessary to make the specified changes, and are not supplied with this service bulletin. These drawings may not be applicable to all airplane configurations or operators. K. Publications Affected Chapter-SectionPublication 27-51-TBD737 Illustrated Parts Catalog 57-53-TBDComponent Maintenance Manual 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. No new Damage Tolerance Inspections (DTIs) are required by this Service Bulletin. L. Interchangeability and Intermixability of Parts Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 24 of 37 BOEING SERVICE BULLETIN 737-57A1304 ### Page 25 2. MATERIAL INFORMATION A. Material - Price and Availability None. B. Industry Support Information Boeing warranty remedies are available for spare parts in warranty as of April 25, 2008. For inspection man-hour reimbursement for airplanes in warranty as of that date, send a warranty claim to Boeing Product Assurance Contracts. If the condition described in this service bulletin is found during the inspection for airplanes in warranty as of that date and additional man-hours and parts are required, send a warranty claim to Boeing Product Assurance Contracts C. Parts Necessary For Each Airplane 1. Kits/Parts None. 2. Parts and Materials Supplied by the Operator None. 3. Parts Modified and Reidentified None. 4. Parts Removed and Not Replaced None. D. Parts Necessary to Change Spares If you have outboard flap, carriage spindles 65C27409-29 / -31 with the High Velocity Oxy-Fuel (HVOF) coating, refer to Paragraph 3.B., Work Instructions for the required action 90 days after these parts are installed. E. Special Tooling - Price and Availability None. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 25 of 37 BOEING SERVICE BULLETIN 737-57A1304 ### Page 26 F. Special Tooling Necessary to do this Service Bulletin No special tools or equipment are necessary to do the change in this service bulletin. But, maintenance and overhaul tools in the manuals given in Paragraph 1.J., References, can be necessary. Examine operator tool supply to make sure all necessary tools are available. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 26 of 37 BOEING SERVICE BULLETIN 737-57A1304 ### Page 27 3. ACCOMPLISHMENT INSTRUCTIONS A. GENERAL INFORMATION CAUTION: KEEP THE WORK AREA, WIRES AND ELECTRICAL BUNDLES CLEAN OF METAL PARTICLES OR CONTAMINATION WHEN YOU USE TOOLS. UNWANTED MATERIAL, METAL PARTICLES OR CONTAMINATION CAUGHT IN WIRE BUNDLES CAN CAUSE DAMAGE TO THE BUNDLES. DAMAGED WIRE BUNDLES CAN CAUSE SPARKS OR OTHER ELECTRICAL DAMAGE. NOTE: 1. The instructions identified in Paragraph 3.B., Work Instructions and the Figure(s) give the recommended sequence of steps. The sequence of steps to do this service bulletin can be changed. 2. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for definition of the acronyms. 3. Obey all of the warnings and cautions given in the specified manual sections. 4. Unless shown differently, these dimensions and tolerances are used: – Linear dimensions are in inches – Tolerance on linear dimensions, other than rivet and bolt edge margins, is plus or minus 0.03 inch – Tolerance on rivet and bolt edge margin is plus or minus 0.05 inch – Angular tolerance is plus or minus 2 degrees – Hole dimensions for standard solid rivets are given in 737 SRM, Chapter 51 – Torque limits to tighten nuts and bolts are given in 737 SRM, Chapter 51 5. For approved fastener and process material substitutions, refer to 737 SRM, Chapter 51. Alternate fasteners are given in 737 SRM Chapter 51 and Boeing Drawing 65-88700. 6. If the length of any fastener specified in this service bulletin does not meet the installation standards 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. 7. A Detailed Inspection is defined as: An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirrors, magnifying lenses, etc. may be necessary. Surface cleaning and elaborate procedures may be required. 8. These work instructions refer to procedures included in other Boeing documents. When the words "refer to" are used and the operator has an accepted alternative procedure, the accepted alternative procedure can be used. When the words "in accordance with" are included in the instruction, the procedure in the Boeing document must be used. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 27 of 37 BOEING SERVICE BULLETIN 737-57A1304 ### Page 28 B. WORK INSTRUCTIONS 1. Determine if you have any suspect carriages with the High Velocity Oxy-Fuel (HVOF) coating installed at WBL 254 or WBL 355. Any carriage installed before March 2006 does not have HVOF coating on it. If you do not have a carriage with HVOF coating, then there is no further action required. All 737-300, -400, -500 carriage sub-assemblies have the base part number 65C27409-( ), the only two suspect part numbers are 65C27409-29 and 65C27409-31. Here are are a couple methods that you can use for part identification. a. You may use your records, if your record review positively identifies the carriage sub-assembly part number and serial number. If your records indicate a sub-assembly 65C27409 with a dash number other than -29, -30, -31, or -32, then there is no further action required. If your records indicate that you have a sub-assembly 65C27409-29 or 65C27409-31, or machined part 65C27409-30 or 65C27409-32, you have a suspect carriage sub-assembly. b. You can identify the carriage by the sub-assembly part number and/or serial number on the part. Gain access as required to the carriages on the outboard flap at WBL 254 and WBL 355. Removal of the flap fairing may be required to read the part mark information on the bottom side of the carriage. All carriages have a serial number steel stamped, dot peened, vibro engraved or electro chemical etched somewhere on the carriage. Refer to FIGURE 1 for the location of the Boeing part number and serial number. See APPENDIX A for a list of suspect carriage serial numbers. If your serial number is on the list you have a suspect carriage sub-assembly. Serial numbers with a R suffix are no longer suspect. If your serial number is not on the list, no further action is required. NOTE: Care must be taken, as an older assembly number does not preclude a newer sub assembly carriage with the HVOF coated spindle. c. If you are not able to identify the sub-assembly part number you must positively identify the carriage serial number or assume you have a suspect carriage or contact Boeing for additional information. See APPENDIX A for a list of suspect carriage serial numbers. 2. Group 1, Configuration 2: Gain access as required to the carriages on the outboard flap at WBL 254 and WBL 355. 3. Group 1, Configuration 2: Supply power to the hydraulic system. Refer to 737-300/400/500 AMM 27-51-00 as an accepted procedure. 4. Group 1, Configuration 2: Extend the flaps to 40 detent or as required, to expose the spindle area of the carriage. 5. Group 1, Configuration 2: Remove power from the hydraulic system. Refer to 737-300/400/500 AMM 27-51-00 as an accepted procedure. 6. Group 1, Configuration 2: Perform the detailed inspections on any suspect carriage with the HVOF thermal coated spindle. Inspect 360 degrees around the exposed sections of the spindle in accordance with Paragraph 1.E., Compliance. Look for corrosion in accordance with FIGURE 2. Flaking metallic particles, disbonded sealant, cracked paint or primer may be potential indications of corrosion. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 28 of 37 BOEING SERVICE BULLETIN 737-57A1304 ### Page 29 a. Remove wing upper surface access panels to expose the aft section of the carriage spindle for detailed inspection. Refer to 737-300/400/500 AMM 27-51-44 as an accepted procedure. (1) If no indication of corrosion is found the carriage does not need to be disassembled or removed. (2) If any potential indication of corrosion is found, remove the carriage from the midflap and perform a detailed inspection for corrosion of the entire spindle surface. (3) If corrosion is found the carriage will need to be replaced with a new or serviceable carriage. Contact Boeing for instructions on how to get your carriage refurbished. Refer to Multi-Operator Message (MOM) MOM-MOM-09-0191-01B for information on the carriage spindle refurbishment program. The refurbished carriage will have a R suffix dot peened or vibroengraved in accordance with SOPM 20-50-10 after the serial number, if refurbished by Boeing. b. Gain access through the front of the trailing edge flap for a detailed inspection or an optional borescope inspection on the carriage spindle forward section. (1) If no indication of corrosion is found the carriage does not need to be disassembled or removed. (2) If any potential indication of corrosion is found, remove the carriage from the midflap and perform a detailed inspection for corrosion of the entire spindle surface. (3) If corrosion is found the carriage will need to be replaced with a new or serviceable carriage. Contact Boeing for instructions on how to get your carriage refurbished. Refer to Multi-Operator Message (MOM) MOM-MOM-09-0191-01B for information on the carriage spindle refurbishment program. The refurbished carriage will have a R suffix dot peened or vibroengraved in accordance with SOPM 20-50-10 after the serial number, if refurbished by Boeing. 7. Group 1, Configuration 2: Perform a gap check or NDT ultrasonic inspection in accordance with service bulletin 737-57A1277, Work Instruction, Section 3.B. Work Package 2 - Midflap/Spindle Carriage Gap Check or Work Package 1 - On Wing NDT Ultrasonic & General Visual Inspection. a. If you find differential movement between the midflap and the carriage spindle, this may be an indication of a severed spindle. Confirm the severed spindle condition be either performing the NDT ultrasonic inspection, or by removing the spindle from the flap. A negative NDT inspection result would allow the carriage to remain in service. A carriage with a failed spindle will need to be replaced with a new or serviceable carriage. Contact Boeing for part disposition. b. If the optional NDT ultrasonic inspection indicates a crack or severed spindle, the carriage will need to be replaced with a new or serviceable carriage. Contact Boeing for part disposition. 8. Group 1, Configuration 2: Use the following step if you need to remove or replace any carriage. NOTE: Replacement with a non suspect carriage, with one that has a serial number with a R suffix or with one that is not coated with HVOF will terminate the inspections for that location. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 29 of 37 BOEING SERVICE BULLETIN 737-57A1304 ### Page 30 a. Remove the outboard trailing edge flap. refer to 737-300/400/500 AMM 27-51-34 as an accepted procedure. b. Remove the midflap carriage from the outboard midflap. Refer to 737-300/400/500 AMM 27-51-44 as an accepted procedure. c. Install the midflap carriage in the outboard midflap. Refer to 737-300/400/500 AMM 27-51-44 as an accepted procedure. d. Install the outboard trailing edge flap. Refer to 737-300/400/500 AMM 27-51-34 as an accepted procedure. 9. Group 1, Configuration 2: Supply power to the hydraulic system. Refer to 737-300/400/500 AMM 27-51-00 as an accepted procedure 10. Group 1, Configuration 2: Retract the flaps fully to 0 detent position. 11. Group 1, Configuration 2: Remove power from the hydraulic system. Refer to 737-300/400/500 AMM 27-51-00 as an accepted procedure. 12. Put the airplane back to a serviceable condition BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1: August 11, 2009 30 of 37 BOEING SERVICE BULLETIN 737-57A1304 ### Page 31 (OCR) BOEING SERVICE BULLETIN 737-57A1304 ACCESS PANEL SPINDLE BEARING BEARING SUPPORT TRAILING EDGE FLAP SERIAL NUMBER OUTBOARD MIDFLAP CARRIAGE CARRIAGE SPINDLE ) PART NUMBER AND SERIAL NUMBER ON OLDER CARRIAGES PART NUMBER AND SERIAL NUMBER A-A 1565427 FIGURE 1: LOCATE PART NUMBER FOR CARRIAGES AT WBL 254 AND WBL 355 WITH HVOF THERMAL COATED SPINDLES (SHEET 1 OF 2) Original Issue: June 02, 2008 Revision 1 August 11, 2009 BOEING PROPRIETARY - 737-57A1304 Copyright © Unpublished Work - See page 1 for details. 31 of 37 ### Page 32 MORE DATAQTYIDENTIFICATIONNAMETASKSTEP (a) (b) (c)-65C27409-29Carriage Sub-assem- bly Identify1 -65C27409-31 (d) (c)-65C27409-( )Carriage Sub-assem- bly Identify2 (a) The carriage part number and serial number are etched at the bottom of the carriage. The serial number is also dot peened, vibro engraved or steel stamped on the top of the carriage, located near the front of the spindle. (b) The serial number must be used to identify the carriage as a suspect HVOF thermal coated part. See APPENDIX A for a list of suspect serial numbers. (c) Care must be taken, as an older assembly number does not preclude a newer sub assembly carriage with the HVOF coated spindle (d) This is the location of the serial number and part number location on older, non suspect carriage sub-as- semblies. Removal of the flap may be required to access this area. FIGURE 1: LOCATE PART NUMBER FOR CARRIAGES AT WBL 254 AND WBL 355 WITH HVOF THERMAL COATED SPINDLES (SHEET 2 OF 2) BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1 August 11, 2009 32 of 37 BOEING SERVICE BULLETIN 737-57A1304 ### Page 33 (OCR) BOEING SERVICE BULLETIN 737-57A1304 This Figure applies only to: Group 1, Configuration 2. CARRIAGE ACCESS PANEL TRAILING EDGE FLAP OUTBOARD MIDFLAP CARRIAGE 1565429 FIGURE 2: INSPECT CARRIAGES SPINDLES WITH HVOF THERMAL COATING FOR CORROSION (SHEET 1 OF 2) Original Issue: June 02, 2008 Revision 1 August 11, 2009 BOEING PROPRIETARY - 737-57A1304 Copyright © Unpublished Work - See page 1 for details. 33 of 37 ### Page 34 MORE DATAQTYIDENTIFICATIONNAMETASKSTEP Do a detailed inspection of the aft section of the spin- dle that is exposed for cor- rosion. (a) (c) -65C27409-29Carriage SpindleInspect1 -65C27409-31 Do a detailed inspection at the forward end of the spindle for corrosion. (a) (b) (c) -65C27409-29Carriage SpindleInspect2 -65C27409-31 (a) Flaking metallic particles, disbonded sealant, cracked paint or primer may be potential indications of corrosion. (b) As an option, use a zero degree borescope and inspect the forward end of the spindle through the front of the trailing edge flap for corrosion. (c) Inspect 360 degrees around the exposed sections of the spindle FIGURE 2: INSPECT CARRIAGES SPINDLES WITH HVOF THERMAL COATING FOR CORROSION (SHEET 2 OF 2) BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1 August 11, 2009 34 of 37 BOEING SERVICE BULLETIN 737-57A1304 ### Page 35 TABLE: 1 Table 1 has been deleted. See Table 2 and Table 3 for suspect carriage serial numbers. APPENDIX A: SERIAL NUMBERS OF SUSPECT CARRIAGE SUB-ASSEMBLIES 65C27409-29 AND -31. (SHEET 1 OF 3) BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1 August 11, 2009 35 of 37 BOEING SERVICE BULLETIN 737-57A1304 ### Page 36 (OCR) BOEING SERVICE BULLETIN 737-57A1304 TABLE 2: SERIAL NUMBERS OF SUSPECT CARRIAGE SUB-ASSEMBLIES B4073 B5206 B4107 B5207 B4111 B4267 B4365 B4422 B4557 B4705 B4768 B4903 B4977 B5056 B5126 B5209 B4112 B4269 B4368 B4423 B4558 B4706 B4780 B4936 B4978 B5057 B5127 B5211 B4164 B4270 B4369 B4424 B4599 B4707 B4781 B4938 B4979 B5058 B5128 B5212 B4168 B4271 B4370 B4425 B4600 B4708 B4782 B4939 B4980 B5075 B5129 B5213 B4172 B4272 B4372 B4426 B4601 B4709 B4784 B4940 B4981 B5076 B5130 B5214 B4180 B4273 B4373 B4427 B4603 B4710 B4785 B4941 B4982 B5077 B5131 B5215 B4195 B4274 B4374 B4428 B4605 B4711 B4786 B4942 B4983 B5079 B5132 B5217 B4201 B4279 B4375 B4434 B4606 B4729 B4787 B4943 B4984 B5080 B5134 B5218 B4203 B4288 B4376 B4439 B4607 B4730 B4788 B4944 B4993 B5082 B5135 B5219 B4204 B4292 B4377 B4440 B4608 B4731 B4789 B4945 B4994 B5092 B5136 B5220 B4205 B4296 B4378 B4441 B4609 B4732 B4790 B4946 B4995 B5093 B5137 B5223 B4206 B4298 B4381 B4442 B4610 B4733 B4799 B4947 B4996 B5094 B5139 B5225 B4207 B4300 B4382 B4443 B4611 B4734 B4819 B4948 B4997 B5095 B5140 B5226 B4208 B4304 B4383 B4444 B4614 B4735 B4820 B4949 B4998 B5096 B5141 B5230 B4209 B4306 B4385 B4454 B4615 B4736 B4837 B4950 B5098 B5142 B5231 B4210 B4310 B4386 B4455 B4665 B4746 B4838 B4951 B5000 B5099 B5143 B5232 B4229 B4311 B4387 B4457 B4666 B4747 B4839 B4952 B5011 B5100 B5144 B5235 B4230 B4312 B4388 B4458 B4667 B4748 B4840 B4953 B5012 B5109 B5145 B5239 B4233 B4313 B4389 B4491 B4668 B4749 B4841 B4957 B5013 B5110 B5240 B4245 B4314 B4396 B4497 B4669 B4751 B4842 B4958 B5014 B5111 B5147 B5242 B4246 B4315 B4397 B4498 B4671 B4752 B4844 B4959 B5015 B5112 B5148 B5243 B4248 B4316 B4406 B4499 B4672 B4754 B4845 B4960 B5113 B5156 B5245 B4252 B4317 B4407 B4501 B4673 B4755 B4846 B4961 B5042 B5114 B5158 B5246 B4253 B4324 B4409 B4502 B4675 B4757 B4851 B4962 B5043 B5115 B5160 B5248 B4254 B4326 B4410 B4503 B4676 B4758 B4852 B4963 B5044 B5116 B5161 B5250 B4255 B4328 B4411 B4504 B4677 B4759 B4853 B4965 B5045 B5117 B5166 B5251 B4256 B4329 B4413 B4505 B4678 B4760 B4854 B4968 B5046 B5118 B5169 B5255 B4257 B4330 B4414 B4506 B4679 B4761 B4855 B4969 B5047 B5119 B5172 B5256 B4258 B4331 B4415 B4508 B4680 B4762 B4859 B4970 B5048 B5120 B5177 B5258 B4259 B4332 B4416 B4509 B4689 B4763 B4878 B4971 B5121 B5178 B4260 B4333 B4417 B4511 B4690 B4764 B4880 B4973 B5051 B5122 B5183 B4261 B4361 B4418 B4512 B4692 B4765 B4881 B4974 B5053 B5123 B5185 65C27409 -31 B4121 B4395 B4519 B4591 B4652 B4727 B4796 B4867 B4898 B5004 B5027 B4163 B4448 B4520 B4594 B4656 B4742 B4821 B4868 B4904 B5005 B5028 B5089 B4184 B4462 B4521 B4595 B4688 B4771 B4822 B4870 B5006 B4197 B4464 B4564 B4596 B4697 B4772 B4823 B4907 B5007 B5037 B4228 B4467 B4565 B4634 B4713 B4774 B4825 B4872 B4908 B5008 B5039 B4231 B4468 B4579 B4635 B4715 B4791 B4826 B4873 B4910 B5017 B5041 B4242 B4480 B4581 B4637 B4716 B4792 B4827 B4874 B4923 B5018 B5065 B4266 B4492 B4586 B4638 B4717 B4793 B4828 B4894 B5001 B5019 B5083 B4285 B4507 B4587 B4639 B4719 B4794 B4829 B4895 B5002 B5022 B5084 B4286 B4514 B4589 B4640 B4720 B4795 B4831 B4897 B5003 B5026 B5086 NOTE: Serial numbers with a R suffix are no longer suspect. APPENDIX A: SERIAL NUMBERS OF SUSPECT CARRIAGE SUB-ASSEMBLIES 65C27409-29 AND -31. (SHEET 2 OF 3) Original Issue: June 02, 2008 Revision 1 August 11, 2009 737-57A1304 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 36 of 37 ### Page 37 TABLE: 3 SERIAL NUMBERS OF SUSPECT CARRIAGE SUB-ASSEMBLIES 65C27409-29 B4193B4161B4155B4105B3988B3947 B4194B4188B4156B4122B3990B3949 B4301B4189B4157B4123B3993B3950 B4190B4158B4125B4101B3960 B4191B4159B4127B4102B3971 B4192B4160B4154B4104B3974 65C27409-31 B3951B3694 NOTE: Serial numbers with a R suffix are no longer suspect. APPENDIX A: SERIAL NUMBERS OF SUSPECT CARRIAGE SUB-ASSEMBLIES 65C27409-29 AND -31. (SHEET 3 OF 3) BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 02, 2008 737-57A1304Revision 1 August 11, 2009 37 of 37 BOEING SERVICE BULLETIN 737-57A1304 --- 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.