### Commercial **Airplanes** 

# 737 Service Bulletin **Number: 737-57A1271** Original Issue: September 11, 2003 Revision 3: February 13, 2012 ATA System: 5752 **SUBJECT:** WINGS - Trailing Edge And Trailing Edge Devices - Trailing Edge Flaps - Outboard Flap, Inboard Track Inspection/Overhaul/Replacement at WBL 254 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. 9E991 ECCN: 

## BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET Copyright © 2003 The Boeing Company Unpublished Work - All Rights Reserved Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable subject matter. Boeing also claims copyright in this document as a compilation and/or collective work. This document includes proprietary information owned by The Boeing Company and/or one or more third parties. Treatment of the document and the information it contains is governed by contract with Boeing. For more information, contact The Boeing Company, P.O. Box 3707, Seattle, Washington 98124. Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, Dreamliner, BBJ, DC-8, DC-9, DC-10, KC-10, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8A, Poseidon and the Boeing livery are all trademarks owned by The Boeing Company; and no trademark license is granted in connection with this document unless provided in writing by Boeing.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 1 of 77 4.0BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 2 of 77 **BOEING SERVICE BULLETIN 737-57A1271**

BLANK PAGE**Table of Contents** Revision Transmittal Sheet............................................ 5 Summary...................................................... 7 1. PLANNING INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 A. Effectivity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 1. Airplanes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2. Spares Affected. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 B. Concurrent Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 C. Reason. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 D. Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 F. Approval. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 G. Manpower. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 H. Weight and Balance Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 I. Electrical Load Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 J. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 1. Existing Data:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 2. Data supplied with this Service Bulletin:. . . . . . . . . . . . . . . . . . . . . . . . . . . 30 3. Installation Drawings Used in the Preparation of this Service Bulletin:. . . . . . . . . . . 30 K. Publications Affected. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 L. Interchangeability and Intermixability of Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . 30 2. MATERIAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 A. Material - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 B. Industry Support Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 C. Parts Necessary For Each Airplane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 1. Kits/Parts:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 2. Parts and Materials Supplied by the Operator:. . . . . . . . . . . . . . . . . . . . . . . . 31 3. Parts Modified and Reidentified:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 4. Parts Removed and Not Replaced:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 D. Parts Necessary to Change Spares. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 F. Special Tooling Necessary to do this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . 33 3. ACCOMPLISHMENT INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 A. GENERAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 B. WORK INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 FIGURE 1: INSPECTION - TRACK WEBS AND FLANGES. . . . . . . . . . . . . . . . . . . . . . . 42 FIGURE 2: INSPECTION - WITH TRACK-TO-WING ATTACHMENT ASSEMBLED. . . . . . . . . . 44 FIGURE 3: INSPECTION - WITH TRACK-TO-WING ATTACHMENT DISASSEMBLED. . . . . . . . 46 FIGURE 4: REPLACEMENT - ANTI-FRET STRIP. . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 FIGURE 5: REPLACEMENT - TAPERED SHIM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 FIGURE 6: TRACK REPAIRS AND BUSHING REPLACEMENT. . . . . . . . . . . . . . . . . . . . . 52 FIGURE 7: ALIGNMENT - TRACK INSTALLATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 FIGURE 8: INSTALLATION - NEW SPARES TRACK - GROUP 1 AIRPLANES - 737-100/200. . . . 63 FIGURE 9: INSTALLATION - NEW SPARES TRACK - GROUP 3 AIRPLANES - 737-300/400/500 . . 68 FIGURE 10: SHOP AID - PRESSURE PLATE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 FIGURE 11: TRACK OVERHAUL - SUPPLEMENTAL INSTRUCTIONS TO OHM 57-53-15. . . . . . 73

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 3 of 77 **BOEING SERVICE BULLETIN 737-57A1271**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 4 of 77 **BOEING SERVICE BULLETIN 737-57A1271**

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### Commercial **Airplanes** 

# 737 Service Bulletin **Revision Transmittal Sheet Number: 737-57A1271**  Original Issue: September 11, 2003 Revision 3: February 13, 2012 ATA System: 5752 **SUBJECT:** WINGS - Trailing Edge And Trailing Edge Devices - Trailing Edge Flaps - Outboard Flap, Inboard Track Inspection/Overhaul/Replacement at WBL 254 This revision includes all pages of the service bulletin. **COMPLIANCE INFORMATION RELATED TO THIS REVISION** No more work is necessary on the airplane(s) changed in accordance with Revision 2 of this service bulletin. Federal Aviation Administration (FAA) Airworthiness Directive AD 78-13-07, AD 90-06-02, AD 2000-25-07 & AD 2002-05-07 are related to this service bulletin.

**REASON FOR REVISION** This revision is sent to incorporate Information Notice 737-57A1271 IN 02. This Information Notice informed operators that sheet 2 of 3 in Figure 1 should be ignored. References to the related AD's were added and additional notes were added to section 3.A. General Information. These sections were changed: 1. Figure 1 was revised to remove the graphic on sheet 2 of 3. 2. 3.A. General Information, additional notes were added. 3. 1.F. Approval, updated to the current statement. The data given in Information Notice 737-57A1271 IN 02 is included in this revision.
Vertical lines are put on the left edge of each page, except in Paragraph 1.A., Effectivity, to show the location of important changes. Pages with no vertical lines have no important changes. **REVISION HISTORY** September 11, 2003 Original Issue: July 30, 2008 Revision 1: January 17, 2011 Revision 2:

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 5 of 77February 13, 2012 Revision 3:

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 6 of 77 **BOEING SERVICE BULLETIN 737-57A1271**

### Commercial **Airplanes** 

# 737 Service Bulletin **Summary Number: 737-57A1271**  Original Issue: September 11, 2003 Revision 3: February 13, 2012 ATA System: 5752 **SUBJECT:** WINGS - Trailing Edge And Trailing Edge Devices - Trailing Edge Flaps - Outboard Flap, Inboard Track Inspection/Overhaul/Replacement at WBL 254 **CONCURRENT REQUIREMENTS** None. **BACKGROUND** This service bulletin gives the instructions to inspect, repair, overhaul, and replace the flap track at Wing Buttock Line (WBL) 254. Since 1989, Boeing has more than thirty reports of cracks in the flap track at WBL 254. Cracks were found in the area of the rear spar attachment, in the track webs, and in the upper and lower flanges at the aft end of the track. The cracks in the area of the rear spar attachment were found at the edge of the hole for the outboard bolt, or at the outer edge of the flange adjacent to the outboard bolt. The cracks in the upper and lower flanges were 0.1 to 1.5 inches in length, and the cracks in the aft end of the webs were 0.75 to 7.0 inches in length. In one incident the aft end of a track had cracks through the two lower flanges, through the two webs, and through the fail-safe spacer. The two upper flanges were all that kept the aft end attached to the remaining part of the track. Also, a track was found with cracks through the two upper and two lower flanges, and through the two webs. The fail-safe spacer was all that kept the aft end of this track attached. This track also had a piece broken out in the curved area of the upper outboard flange. Some of the reports also show that tracks were found loose and had corrosion in the area of the rear spar attachment. These tracks that were found loose also had damaged, or missing, anti-fret strips and tapered shims. Initially, the loose tracks were thought to be caused by a weak bond of, or compression damage to, the phenolic anti-fret strip installed in the joint between the track and rear spar. But, subsequent reports showed that the sequence and procedures used during track installation could also be a cause of loose tracks. During installation, when full torque is applied to the forward attach bolt, it can cause the track to move laterally at the rear spar joint. If the track moves laterally at the rear spar joint during the installation procedures, it can put a side load on the inboard aft attach bolt. Then, when the inboard aft attach bolt is tightened to the specified torque value, some of the torque can be absorbed by friction. Subsequently, because of the friction, the torque applied to the bolt is not sufficient to hold the track tight against the rear spar structure. Continued operation with a cracked and/or loose attachment at the rear spar could cause the track to break. A result of a broken track could be the loss of the outboard trailing edge flap, and may preclude continued safe flight and landing of the airplane. The new spares track assemblies have increased upper flange thickness in the attachment area that mates with the wing rear spar, and improved coatings and processes for corrosion protection. The new track for the 737-100/200 also has an improved fail-safe configuration at the forward end that makes it comparable to the 737-300/400/500 track assembly.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 7 of 77The inspections given in this service bulletin will find the conditions that make repair or replacement of the flap track necessary. The repairs, scheduled overhauls, correct alignment during installation, and regularly scheduled maintenance will keep tracks in a serviceable condition. There is no terminating action for this service bulletin. This service bulletin replaces Service Bulletins 737-57A1082, 737-57A1249, and 737-57A1265. Boeing Service Related Problem (SRP) 737-SRP-57-0131 is related to this service bulletin. **ACTION (PRR 35005-238RS)** Do an initial inspection of the track webs, track flanges, and the track-to-wing attachment at WBL 254. Look for stop-drill repairs and cracks in the track webs. Look for stop-drill repairs, cracks, nicks, corrosion pits, galling, and other signs of damage on the track flanges. Look for corrosion, loose bolts, and a damaged or a missing anti-fret strip and/or tapered shim at the track-to-wing attachment. Remove a track from service if it has a stop-drill repair. If possible, make repairs to the edges of the track flange, but replace the track if cracks are found in the webs. Disassemble the track-to-wing joint and do more inspections if signs of corrosion, loose bolts, or a damaged or missing anti-fret strip or tapered shim are found. If necessary make and install a new anti-fret strip, and/or tapered shim, and remove corrosion and make repairs to the track. Do the procedures to correctly align the track during assembly of the track-to-wing joint. If the track cannot be repaired, install a serviceable flap track assembly. During installation of a serviceable flap assembly, do the procedures to correctly align the track during installation. Do the repeat inspections and schedule the initial, and repeat overhaul, of a flap track at the times given in Paragraph 1.E., Compliance. Flap track assemblies with short fail-safe bars, part number 65-46428-31 and 65-46428-33 must be removed from service during inspection or repair. **EFFECTIVITY** All 737-100, -200, -200C, -300, -400, and -500 airplanes line numbers 1 through 3132. **COMPLIANCE** Federal Aviation Administration (FAA) Airworthiness Directive AD 78-13-07, AD 90-06-02, AD 2000-25-07 & AD 2002-05-07 are related to this service bulletin. Refer to Paragraph 1.E., Compliance, for the repeat inspection and overhaul thresholds. 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. **INDUSTRY SUPPORT INFORMATION** Boeing warranty remedies are not available for the inspection, and/or repair procedures, given in this service bulletin.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 8 of 77 **BOEING SERVICE BULLETIN 737-57A1271 MANPOWER**  **Elapsed Hours Total Task Hours**  **Airplanes** 23 82 All
**MATERIAL INFORMATION** Operator Supplied Parts/Materials. Refer to Paragraph 2.A., Material - Price and Availability.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 9 of 77 **BOEING SERVICE BULLETIN 737-57A1271**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 10 of 77 **BOEING SERVICE BULLETIN 737-57A1271**

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### Commercial **Airplanes** 

# 737 Service Bulletin **Number: 737-57A1271** Original Issue: September 11, 2003 Revision 3: February 13, 2012 ATA System: 5752 **SUBJECT:** WINGS - Trailing Edge And Trailing Edge Devices - Trailing Edge Flaps - Outboard Flap, Inboard Track Inspection/Overhaul/Replacement at WBL 254 **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.
**DESCRIPTION CONFIGURATION**  **GROUP** 737-100/-200/-200C, airplanes with flap track assemblies 65-46428-() or 65C35380-(). Inspection, overhaul and replacement instructions given are applicable to Group 1 airplanes - 1

737-200/-200C, airplanes with flap track assemblies 65-67158-() or 65C35380-(). If necessary, these tracks can be replaced with 65-67158-6. - 2

737-300/400/500 airplanes with 65-46428-(), 65C35616-(), 65C35387-(), 65C34812-() or 65C35380-() flap track assemblies. The inspection, overhaul, and replacement instructions given in this service bulletin are applicable to Group 3 airplanes. - 3

Airplane Models: 737-100, 737-200, 737-200C, 737-300, 737-400, 737-500 **Group Variable Number**  1 PA001 - PA022 1 PA099 1 PA231 - PA232 2 PC001 - PC005 1 PG001 - PG075

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 11 of 77**Group Variable Number**  1 PG199 1 PG201 - PG230 1 PG251 - PG255 1 PG271 - PG279 1 PG301 - PG314 1 PG331 - PG332 1 PG351 - PG356 1 PG375 1 PG401 - PG403 1 PG431 - PG442 1 PG471 - PG475 1 PG501 - PG505 1 PG571 - PG586 1 PG621 - PG630 1 PG651 - PG652 1 PG701 - PG705 1 PH001 1 PH011 - PH013 1 PH021 - PH024 1 PH701 - PH715 1 PH731 - PH732 1 PH741 - PH743 2 PJ001 - PJ002 1 PJ003 - PJ009 2 PJ031 - PJ032 2 PJ071 - PJ072 2 PJ101 - PJ104 1 PJ105 - PJ119 1 PJ201 - PJ219 3 PJ301 - PJ302 3 PJ551 - PJ561 3 PJ601 - PJ615 3 PJ811

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 12 of 77 **BOEING SERVICE BULLETIN 737-57A1271 Group**  **Variable Number** 3 PJ816 - PJ817 1 PK026 - PK029 1 PK041 - PK053 1 PK061 - PK070 1 PK081 - PK082 1 PK091 - PK099 1 PK101 - PK103 1 PK111 - PK120 1 PK141 - PK146 1 PK201 - PK204 1 PK211 - PK223 1 PK231 - PK241 1 PK251 - PK258 1 PK271 - PK274 1 PK281 - PK289 1 PK291 1 PK301 - PK318 1 PK341 1 PK351 - PK361 1 PK391 1 PK431 - PK433 1 PK451 - PK452 1 PK461 - PK469 1 PK495 1 PK501 - PK504 1 PK511 - PK515 1 PK519 1 PK521 - PK528 1 PK541 - PK565 1 PK581 1 PK591 - PK599 1 PK601 - PK617 1 PK621 - PK637

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 13 of 77 **BOEING SERVICE BULLETIN 737-57A1271 Group**  **Variable Number** 1 PK641 - PK642 1 PK661 - PK666 1 PK671 - PK681 1 PK691 - PK697 1 PK711 - PK716 1 PK731 - PK765 1 PK771 - PK779 1 PK801 - PK804 1 PK819 - PK827 1 PK830 1 PK861 - PK863 1 PK871 - PK874 1 PK881 - PK884 1 PK901 - PK938 1 PK971 - PK974 1 PL001 - PL028 1 PL061 1 PL081 1 PL101 - PL113 1 PL151 1 PL171 - PL172 1 PL201 - PL203 1 PL221 1 PL401 - PL417 1 PL421 1 PL441 1 PL451 - PL456 1 PL471 1 PL491 1 PL501 - PL506 1 PL551 - PL562 1 PL581 1 PL601 - PL603

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 14 of 77 **BOEING SERVICE BULLETIN 737-57A1271 Group**  **Variable Number** 1 PL611 1 PL621 - PL626 1 PL631 - PL632 1 PL711 - PL712 1 PL716 - PL747 1 PL756 1 PL758 1 PL761 - PL770 1 PL781 - PL788 1 PL793 2 PL801 - PL803 1 PM001 - PM006 1 PM016 - PM017 1 PM021 - PM023 1 PM051 - PM066 1 PM101 - PM119 1 PM141 - PM142 1 PM171 1 PM181 1 PM251 - PM255 1 PM281 - PM283 3 PM381 - PM399 3 PM401 - PM417 3 PM541 - PM564 1 PN001 - PN002 1 PN021 - PN043 1 PN081 - PN086 1 PN101 - PN117 1 PN131 - PN163 1 PN401 - PN420 1 PN431 - PN433 1 PN451 - PN456 1 PN471 - PN474

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 15 of 77 **BOEING SERVICE BULLETIN 737-57A1271 Group**  **Variable Number** 1 PN481 1 PN491 - PN493 1 PN501 - PN502 1 PN511 - PN512 1 PN521 3 PP001 - PP054 3 PP101 - PP169 3 PP181 - PP199 3 PP201 - PP205 3 PP221 3 PP231 - PP243 3 PP281 - PP286 3 PP301 - PP305 3 PP351 - PP353 3 PP376 - PP384 3 PP391 - PP393 3 PP401 - PP440 3 PP471 - PP475 3 PP501 - PP522 3 PP631 - PP634 3 PP651 - PP652 3 PP671 - PP699 3 PP701 - PP733 3 PP771 - PP779 3 PP801 - PP808 3 PP821 - PP827 3 PP831 - PP848 3 PP851 - PP852 3 PP861 - PP877 3 PP891 - PP899 3 PP901 - PP936 3 PP946 - PP948 3 PP951 - PP952

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 16 of 77 **BOEING SERVICE BULLETIN 737-57A1271 Group**  **Variable Number** 3 PP961 - PP967 3 PP981 - PP991 3 PP993 3 PQ001 - PQ016 3 PQ026 - PQ041 3 PQ051 - PQ092 3 PQ101 - PQ199 3 PQ201 - PQ202 3 PQ221 - PQ237 3 PQ241 - PQ243 3 PQ251 - PQ267 3 PQ281 - PQ299 3 PQ301 - PQ307 3 PQ331 - PQ332 3 PQ341 - PQ348 3 PQ361 - PQ373 3 PQ391 - PQ395 3 PQ401 - PQ418 3 PQ421 3 PQ431 - PQ438 3 PQ447 - PQ448 3 PQ451 3 PQ454 3 PQ471 - PQ475 3 PQ479 - PQ481 3 PQ486 - PQ487 3 PQ491 - PQ493 3 PQ771 - PQ772 3 PQ791 - PQ793 3 PQ801 - PQ805 3 PQ931 - PQ935 3 PQ951 3 PQ971 - PQ997

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 17 of 77 **BOEING SERVICE BULLETIN 737-57A1271 Group**  **Variable Number** 3 PR001 - PR017 3 PR021 - PR034 3 PR041 - PR045 3 PR061 - PR072 3 PR077 - PR082 3 PR091 - PR092 3 PR096 3 PR101 3 PR121 - PR122 3 PR131 - PR132 3 PR141 - PR143 3 PR161 - PR172 3 PR181 3 PS601 - PS631 3 PS636 - PS638 3 PS641 - PS644 3 PS651 - PS657 3 PS666 - PS669 3 PS691 - PS692 3 PS701 - PS706 3 PS751 - PS799 3 PS811 3 PS836 - PS837 3 PS841 - PS846 3 PS851 - PS852 3 PS856 3 PS861 - PS863 3 PS866 - PS868 3 PS871 - PS874 3 PS896 - PS897 3 PS901 - PS941 3 PS956 - PS957 3 PS961 - PS963

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 18 of 77 **BOEING SERVICE BULLETIN 737-57A1271 Group**  **Variable Number** 3 PS971 - PS978 3 PT001 - PT015 3 PT021 - PT031 3 PT041 - PT064 3 PT101 - PT105 3 PT121 - PT138 3 PT146 - PT148 3 PT161 - PT170 3 PT181 - PT188 3 PT211 - PT220 3 PT295 3 PT301 - PT309 3 PT331 - PT360 3 PT381 - PT399 3 PT401 - PT438 3 PT501 - PT517 3 PT561 - PT565 3 PT581 - PT586 3 PT611 - PT621 3 PT641 - PT644 3 PT651 - PT656 3 PT671 - PT672 3 PT681 - PT685 3 PT701 - PT703 3 PT716 - PT717 3 PT721 - PT725 3 PT801 - PT834 3 PT851 - PT854 3 PT871 - PT886 3 PT901 - PT930 3 PT971 - PT973 3 PT981 - PT985 3 PT996

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 19 of 77 **BOEING SERVICE BULLETIN 737-57A1271 Group**  **Variable Number** 3 PU001 - PU025 3 PU301 3 PU311 - PU313 3 PV001 - PV055 3 PV201 - PV209 3 PV226 - PV229 3 PV231 - PV237 3 PV271 - PV272 3 PV281 - PV287 3 PV296 3 PV301 - PV302 3 PV351 3 PV356 - PV357 3 PW001 - PW054 3 PW061 - PW068 3 PW072 3 PW086 - PW088 3 PW091 - PW094 3 PW101 - PW102 3 PW106 3 PW111 - PW120 3 PW156 - PW157 3 PW161 - PW171 3 PW201 - PW252 3 PW261 - PW268 3 PW271 - PW276 3 PW278 3 PW281 - PW293 3 PW296 3 PW301 - PW327 3 PW401 - PW408 3 PW411 - PW418 3 PW421 - PW424

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 20 of 77 **BOEING SERVICE BULLETIN 737-57A1271 Group**  **Variable Number** 3 PW431 - PW435 3 PW441 - PW450 3 PW461 - PW467 3 PW501 - PW504 3 PW511 - PW522 3 PW524 - PW550 3 PW556 - PW557 3 PW561 - PW564 3 PW571 - PW576 3 PW591 - PW596 3 PW611 - PW622 3 PW631 - PW637 3 PW661 - PW662 3 PW681 - PW683 3 PW701 - PW702 3 PW711 - PW717 3 PW741 - PW742 3 PW761 3 PW771 3 PW831 3 PW851 - PW856 1 PX071 1 PX701 2 PY001 - PY006 1 PY007 - PY008 1 PY021 - PY022 1 PY031 1 PY036 - PY037 1 PY046 - PY048 1 PY051 - PY053 1 PY056 - PY057 1 PY101 - PY103 1 PY111 - PY113

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 21 of 77 **BOEING SERVICE BULLETIN 737-57A1271 Group**  **Variable Number** 1 PY131 - PY135 1 PY141 - PY143 1 PY151 - PY154 1 PY156 - PY157 1 PY161 - PY162 1 PY166 1 PY191 1 PY201 1 PY221 - PY222 1 PY231 1 PY241 - PY244 1 PY270 - PY275 1 PY281 1 PY286 2 PY301 - PY304 2 PY321 - PY323 2 PY341 - PY346 2 PY361 - PY362 1 PY381 1 PY401 1 PY409 - PY411 1 PY421 - PY422 1 PY441 1 PY451 1 PY461 - PY463 1 PY591 - PY595 1 PY611 - PY612 1 PY621 1 PY631 1 PY651 1 PY671 - PY672 1 PY721 1 PY741

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 22 of 77 **BOEING SERVICE BULLETIN 737-57A1271**2. Spares Affected Examine your spares supply for the parts or components identified in Paragraph 2.C., Parts Necessary for Each Airplane. If any parts or components are found, refer to Paragraph 2.C. for the recommended use. **B. Concurrent Requirements** None. **C. Reason** This service bulletin gives the instructions to inspect, repair, overhaul, and replace the flap track at Wing Buttock Line (WBL) 254. Since 1989, Boeing has more than thirty reports of cracks in the flap track at WBL 254. Cracks were found in the area of the rear spar attachment, in the track webs, and in the upper and lower flanges at the aft end of the track. The cracks in the area of the spar attachment were found at the edge of the hole for the outboard bolt, or between the center bolt hole and the outboard bolt hole, or at the outer edge of the flange adjacent to the outboard bolt. The cracks in the upper and lower flanges were 0.1 to 1.5 inches in length, and the cracks in the aft end of the webs were 0.75 to 7.0 inches in length. In one incident the aft end of a track had cracks through the two lower flanges, through the two webs, and through the fail-safe spacer. The two upper flanges were all that kept the aft end attached to the remaining part of the track. Also, a track was found with cracks through the two upper and two lower flanges, and through the two webs. The fail-safe spacer was all that kept the aft end of this track attached. This track also had a piece broken out in the curved area of the upper outboard flange. Some of the reports also show that tracks were found loose and had corrosion in the area of the rear spar attachment. These tracks that were found loose also had damaged, or missing, anti-fret strips and tapered shims. Initially, the loose tracks were thought to be caused by a weak bond of, or compression damage to, the phenolic anti-fret strip installed in the joint between the track and rear spar. But, subsequent reports showed that the sequence and procedures used during track installation could also be a cause of loose tracks. During installation, when full torque is applied to the forward attach bolt, it can cause the track to move laterally at the rear spar joint. If the track moves laterally at the rear spar joint during the installation procedures, it can put a side load on the inboard aft attach bolt. Then, when the inboard aft attach bolt is tightened to the specified torque value, some of the torque can be absorbed by friction. Subsequently, because of the friction, the torque applied to the bolt is not sufficient to hold the track tight against the rear spar structure. Continued operation with a cracked and/or loose attachment at the rear spar could cause the track to break. A result of a broken track could be the loss of the outboard trailing edge flap, and may preclude continued safe flight and landing of the airplane. The new spares track assemblies have increased upper flange thickness in the attachment area that mates with the wing rear spar, and improved coatings and processes for corrosion protection. The new track for the 737-100/200 also has an improved fail-safe configuration at the forward end that makes it comparable to the 737-300/400/500 track assembly. The inspections given in this service bulletin will find the conditions that make repair or replacement of the flap track necessary. The repairs, scheduled overhauls, correct alignment during installation, and regularly scheduled maintenance will keep tracks in a serviceable condition. There is no terminating action for this service bulletin.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 23 of 77 **BOEING SERVICE BULLETIN 737-57A1271**This service bulletin replaces Service Bulletins 737-57A1082, 737-57A1249, and 737-57A1265. Boeing Service Related Problem (SRP) 737-SRP-57-0131 is related to this service bulletin. Revision 01 is sent to include the data given in Information Notice 737-57A1271 IN 01 and make these changes: – The two notes that read "Some small cracks in the web, that start in the fastener holes, can be repaired with the overhaul instructions given in 737 OHM 57-53-15" are removed from the work instructions. Also, this statement is not added to the Action and Description paragraphs as stated in Information Notice 737-57A1271 IN 01. – Three notes are added to Paragraph 1.E., Compliance. The notes give more data about the overhaul of the flap tracks as related to the initial and repeat inspections. – A statement that shows the relationship between this service bulletin, Service Bulletin 737-57A1082, AD 90-06-02, and Boeing Document D6-38505 is added to Paragraph 1.F., Approval. – Figure 7, Note (d), List Item 3 is corrected to read "inboard attach hole" and a caution is added before List Item 3 to make sure that the inner diameter of the steel bushing is not increased at the inboard attach bolt. – Figure 9, Note (b) is moved to the part number column of Step 9 and the note is changed to add Track Assembly 65C35616-5. Note (d) is added to Step 9 to give part usage data. – Figure 11, added an upper limit for the thermal spray coating dimensions. Added additional coating information to view E-E, and added a new detail view "C". Note (c) is added to Step 2 to show thermal spray coating requirements. Revision 02 is sent to make to following changes: – 1.A. Effectivity: - Added reference to 65C35380-( ) and 65-67158-6 part numbers in the group configuration description. – 1.D. Description: - Added reference to 65C35380-( ) and 65-67158-6 part numbers in the group configuration description. - Added Maintenance zone table. – 1.E. Compliance: - Added statement to remove flap track assemblies with short failsafe bars from service. – 1.K. Publications Affected: - Added damage tolerance statement. – 2.C. Parts Necessary For Each Airplane: - Revised note (c) for spare parts availability. – 3.B. Work Instructions: - Clarified the inspection steps. – Figure 3 and 7: - Clarified notes. – Figure 8: - Corrected fastener grip length for step 11. Revision 3 is sent to incorporate Information Notice 737-57A1271 IN 02. This Information Notice informed operators that sheet 2 of 3 in Figure 1, in revision 2 of this service bulletin should be ignored.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 24 of 77 **BOEING SERVICE BULLETIN 737-57A1271 D. Description**  Do an initial inspection of the track webs, track flanges, and the track-to-wing attachment at WBL 254. Look for stop-drill repairs and cracks in the track webs. Look for stop-drill repairs, cracks, nicks, corrosion pits, galling, and other signs of damage on the track flanges. Look for corrosion, loose bolts, and a damaged or a missing anti-fret strip and/or tapered shim at the track-to-wing attachment. Remove a track from service if it has a stop-drill repair. If possible, make repairs to the edges of the track flange, but replace the track if cracks are found in the webs. Disassemble the track-to-wing joint and do more inspections if signs of corrosion, loose bolts, or a damaged or missing anti-fret strip or tapered shim are found. If necessary make and install a new anti-fret strip, and/or tapered shim, and remove corrosion and make repairs to the track. Do the procedures to correctly align the track during assembly of the track-to-wing joint. If the track cannot be repaired, install a serviceable flap track assembly. During installation of a serviceable flap assembly, do the procedures to correctly align the track during installation. Do the repeat inspections and schedule the initial, and repeat overhaul, of a flap track at the times given in Paragraph 1.E., Compliance. Flap track assemblies with short fail-safe bars, part number 65-46428-31 and 65-46428-33, must be removed from service if damage is found during an inspection or repair. If damage is not found, these flap tracks with short fail-safe bars must be removed from service at the initial overhaul. **NOTE:** It will be necessary to keep records of the flap tracks because they can be moved from one airplane to another. **NOTE:** The steel flap track and the aluminum spacer block are a machined set. During initial assembly, the aluminum spacers are machined to fit the machined slot in the steel tracks. Thus, each assembly must be kept together, as a machined set, during the overhaul procedures. The airplane effectivity is divided in three groups as follows: • Group 1 are 737-100/200 airplanes with 65-46428-() or 65C35380-( ) Flap Track Assemblies. The inspection, overhaul, and replacement instructions given in this service bulletin are applicable to Group 1 airplanes. • Group 2 are 737-200 airplanes with 65-67158-() or 65C35380-( ) Flap Track Assemblies. The inspection and overhaul instructions given in this service bulletin are applicable to Group 2 airplanes. If necessary, these tracks can be replaced with part number 65-67158-6. • Group 3 are 737-300/400/500 airplanes with 65-46428-(), 65C35616-(), 65C35387-(), 65C34812-() or 65C35380-( ) Flap Track Assemblies. The inspection, overhaul, and replacement instructions given in this service bulletin are applicable to Group 3 airplanes. Revision 1 - no more work is necessary on airplanes changed as shown in initial release of this service bulletin. Revision 2 - No more work is necessary on airplanes changed in accordance with the original issue or Revision 1 of this service bulletin. Revision 3 - No more work is necessary on airplanes changed in accordance with Revision 2 of this service bulletin. The work in this service bulletin is done in the maintenance zone(s) given below.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 25 of 77 **BOEING SERVICE BULLETIN 737-57A1271 Group 1-2:** 
**Affected Maintenance Zones Zone**  **Model** 3-7, 4-7 737-100, 737-200, 737-200C **Group 3:**
**Affected Maintenance Zones Zone**  **Model** 307, 407 737-300, 737-400, 737-500 **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. Federal Aviation Administration Airworthiness Directive (AD) 78-13-07, Amendment 39-3253; AD 2000-25-07, Amendment 39-1204; AD 2002-05-07, Amendment 39-12675; and AD 90-06-02, Amendment 39-6489 are related to this service bulletin. Boeing recommends the inspection and overhaul of the flap track installed at Left WBL 254, and Right WBL 254, as follows. • Initial Inspection. Perform the initial inspection of the flap track, using the instructions in this service bulletin, prior to the later of the times specified below: • 15,000 flight cycles or 8 years since new or overhauled, whichever occurs first, or • 180 days after the issue date on this service bulletin • Within 24 months of the last inspection performed in accordance with Part I of the Accomplishment Instructions of Boeing Service Bulletin 737-57A1249, Revision 1, including Appendix A, dated June 1, 2000.

**NOTE:** Overhaul of a flap track, with the overhaul instructions given in this service bulletin, can satisfy the initial inspection. Flap track assemblies with short failsafe bars, part number 65-46428-31 and 65-46428-33 must be removed from service during inspection or repair. **NOTE:** Tracks overhauled to satisfy the initial inspection must be scheduled for the repeat inspections and repeat overhauls. • Initial Overhaul. Do an initial overhaul of the flap track, using the instructions in this service bulletin, within 10,000 flight cycles or 4 years, whichever occurs first, of the Initial Inspection. • Repeat Inspections. Perform repeat inspections of the flap track within 10,000 flight cycles or 4 years, whichever occurs first, of the overhaul using the instructions in this service bulletin.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 26 of 77 **BOEING SERVICE BULLETIN 737-57A1271 NOTE:**  Overhaul of a flap track, with the overhaul instructions given in this service bulletin, can satisfy a repeat inspection. • Repeat Overhauls. Repeat the overhaul of the flap track, using the instructions in this service bulletin, at intervals not to exceed 20,000 flight cycles or 8 years, whichever occurs first. **F. Approval** This service bulletin was examined by the Federal Aviation Administration (FAA). The changes specified in this service bulletin comply with the applicable regulations and are FAA approved, as well as European Aviation Safety Agency (EASA)/Joint Aviation Authorities (JAA) approved for all EASA/JAA approved airplanes listed in the service bulletin effectivity. This service bulletin and its approval were based on the airplane in its original Boeing delivery configuration or as modified by other approved Boeing changes. If an airplane has a non-Boeing modification or repair that affects a component or system also affected by this service bulletin, the operator is responsible for obtaining appropriate regulatory agency approval before incorporating this service bulletin. This service bulletin has been approved by the FAA. In addition, the Manager of the FAA Seattle Aircraft Certification Office approves these actions: 1. Performance of all requirements defined in "WORK INSTRUCTIONS, INSPECTION - TRACK WEB AND FLANGES" constitutes, for the inboard track only, an alternative method of compliance to the inspection intervals, methods and repair required by paragraphs A, B, C, and D of Airworthiness Directive 78-13-07. All other provisions of Airworthiness Directive 78-13-07, not specifically referenced in this statement, remain fully effective and must be complied with. The requirements for the outboard track defined by Airworthiness Directive 78-13-07, remain in effect and are not affected by the alternative method of compliance statement, described above. 2. Performance of detail visual inspection and requirements defined in "WORK INSTRUCTIONS, INSPECTION - TRACK WEB AND FLANGES" constitutes an alternative method of compliance to the inspection methods and corrective action required by paragraphs (a) and (b) of Airworthiness Directive 2000-25-07. All other provisions of Airworthiness Directive 2000-25-07, not specifically referenced in this statement, remain fully effective and must be complied with. 3. Performance of inspections defined in "WORK INSTRUCTIONS, INSPECTION - WITH TRACK-TO-WING ATTACHMENT ASSEMBLED" constitutes an alternative method of compliance to the inspection methods required by paragraphs (a)(1), (a)(2) and (d) of Airworthiness Directive 2002-05-07. All other provisions of Airworthiness Directive 2002-05-07, not specifically referenced in this statement, remain fully effective and must be complied with. 4. Performance of actions defined in "WORK INSTRUCTIONS, INSPECTION - WITH TRACK-TO-WING ATTACHMENT DISASSEMBLED" constitutes an alternative method of compliance to the rework required by paragraph (c) of Airworthiness Directive 2002-05-07. all other provisions of Airworthiness Directive 2002-05-07, not specifically referenced in this statement, remain fully effective and must be complied with.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 27 of 77 **BOEING SERVICE BULLETIN 737-57A1271**5. The Manager of the FAA Seattle Aircraft Certification office approves the overhaul of the outboard flap inboard track per the Accomplishment Instructions in Service Bulletin 737-57A1271, Revision 3, as an Alternative Method of Compliance to the modification requirements of Paragraph A of AD 90-06-02 for SB 737-57A1082 only. All provisions of AD 90-06-02 not specifically referenced in the above statement, including the modification threshold, remain fully applicable and must be complied with. **G. Manpower** The table below shows an estimate of the task-hours necessary to do this change 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 examine the work — Time to cure the materials — Time to make the parts — Time to find the tools. **Elapsed Hours Task-Hours**  **Number of Per- sons**  **Task**
4.0 24.0 (a) 6 Open Access 3.0 6.0 2 Inspect (b) (b) (b) Repair 8.0 16.0 4 Replace 5.0 30.0 (a) 6 Close Access 3.0 6.0 2 Test 23.0 82.0 TOTAL FOR EACH AIRPLANE The estimate shows the man hours necessary for the access procedures to do the inspection with the track-to-wing attachment disassembled. (a)No estimate given for the repair procedures. (b) **H. Weight and Balance Changes** None. **I. Electrical Load Data** Not changed.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 28 of 77 **BOEING SERVICE BULLETIN 737-57A1271 J. References**  1. Existing Data: a. Engineering Change Memo PRR 35005-238RS b. Service Related Problem (SRP) 737-SRP-57-0131 c. 737-100/200 Maintenance Manual (AMM) Subject 12-20-0, 27-51-72, 27-51-111, 27-51-121, 27-51-151, 27-51-281 d. 737-300/400/500 Maintenance Manual (AMM) Subject 27-51-49. 27-51-52 e. 737 Nondestructive Test (NDT) Manual 737, Part 4, Subject 57-50-01 f. 737 Nondestructive Test (NDT) Manual 737, Part 6, Subject 57-50-01 g. 737 Nondestructive Test (NDT) Manual 737, Part 6, Subject 57-50-06 h. 737 Nondestructive Test (NDT) Manual 737, Part 6, Subject 51-00-00, Figure 19. i. 737 Nondestructive Test (NDT) Manual 737, Part 6, Subject 51-00-00, Figure 24. j. Overhaul Manual 57-53-15 k. 737 Structural Repair Manual (SRM) Chapter 51 l. Boeing Standard Overhaul Practices Manual (BSOPM) 20-10-01, 20-10-03. 20-30-02, 20-42-05, 20-43-03 m. Boeing Service Bulletin 737-57A1082 n. Boeing Service Bulletin 737-57-1203 o. Boeing Service Bulletin 737-57A1249 p. Boeing Service Bulletin 737-57A1265 q. FAA Airworthiness Directive 78-13-07, Amendment 39-3253 r. FAA Airworthiness Directive 90-06-02, Amendment 39-6489 s. FAA Airworthiness Directive 2000-25-07, Amendment 39-12041 t. FAA Airworthiness Directive 2002-05-07, Amendment 39-12675 u. Boeing Document D6-38505 v. Boeing Parts Standards Document D-590 w. Boeing Drawing 65-88700

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 29 of 77 **BOEING SERVICE BULLETIN 737-57A1271**2. Data supplied with this Service Bulletin: None. 3. Installation Drawings Used in the Preparation of this Service Bulletin:
**Title Drawing Number**  Flap Track Installation - Inbd And Outbd Flap 65-46429 Track Assy - Outboard Flap 65-46428 Track Assy - Outboard Flap 65C34812 These drawings were used to prepare this service bulletin. These drawings are not necessary to make the specified changes, and are not supplied with this service bulletin. These drawings may not be applicable to all airplane configurations or operators. **K. Publications Affected** 1. Publications: None. 2. Damage Tolerance Based Structural Inspections: Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the Maintenance Program. This service bulletin affects FCS but no new DTIs are necessary. **L. Interchangeability and Intermixability of Parts** Refer to Paragraph 2.C., Parts Necessary For Each Airplane, for interchangeability and intermixability information.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 30 of 77 **BOEING SERVICE BULLETIN 737-57A1271 2. MATERIAL INFORMATION**  **A. Material - Price and Availability** The operator can supply the parts and materials shown in Paragraph 2.C., Parts Necessary For Each Airplane. As an alternative, operators can purchase the parts from Boeing Spares. This service bulletin does not show the Boeing price and supply data. **B. Industry Support Information** Boeing warranty remedies are not available for the inspection, and/or repair procedures given in this service bulletin. **C. Parts Necessary For Each Airplane** 1. Kits/Parts: None. 2. Parts and Materials Supplied by the Operator: **NOTE:** Quantity is for the replacement of one flap track.
**Notes Existing Part Number**  **Name QTY**  **Part Number / Specification**  (b) (a) Flap Track Assy (Group 1 Airplanes) 1 65-46428-36 (c) 65-67158-2, or -3, or -6 Flap Track Assy (Group 2 Airplanes)

- - (e) (d) Flap Track Assy (Group 3 Airplanes) 1 65C34812-8 (j) 66-23210-6 Sleeve 1 66-23210-1 (h) (j)

- Bolt 1 BACB30LE7HK26 (i) (j)

- Bolt 1 BACB30LE8HK32 (i) (j)

- Bolt 1 BACB30LE8HK31 (j)

- Bolt 1 BACB30LT7DU27 (j)

- Bolt 1 BACB30LT7DU17 (j)

- Nut 1 BACN10HR7CD (j)

- Nut 1 BACN10JD107 (j)

- Washer 1 BACW10BN7SC (j)

- Washer 1 BACW10BP7C (j)

- Washer 1 BACW10BP7CD (j)

- Washer 1 BACW10BP7P (k)

- Washer, Torque-Indicating 1 BACW10DN8 (j)

- Barrel Nut 1 NAS577B8A

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 31 of 77 **BOEING SERVICE BULLETIN 737-57A1271 Notes**  **Existing Part Number Name**  **QTY Part Number /**  **Specification** (j)

- Retainer 1 NAS578-8A (j)

- Washer

- NAS1149F0716P (j)

- Washer

- NAS1149F0732P (j)

- Washer

- NAS1149F0763P (i) (j)

- Washer

- NAS1149F0816P (i) (j)

- Washer

- NAS1149F0832P

- Lockwire

- NASM20995C32

- Cotter Pin 1 MS24665-285

- Sealant 1 pt BMS 5-95

- Primer 8 oz BMS 10-11, Type I Refer to BSOPM 20-43-03 - Chemical Conversion Coating 8 oz Type 2, Class A

- Corrosion Preventive Compound 8 oz MIL-C-11796, Class 3 (l)

- Thermal Spray Powder

- BMS 10-67, Type 1, Class 2 or 4 (l)

- Retaining Compound

- Loctite 262 or MIL- S-46163, Type II, Grade O (l)

- Adhesion Promoter

- Locquic Primer N 7649
65-46428-2, or -3, or -5, or -7, or -9, or -11, or -15, or -17, or -19, or -21, or -23, or -25, or-27, or -33, or -35. (a)You can use the existing part 65-46428-2, or -3, or -5, or -7, or -9, or -11, or -15, or -17, or -19, or -21, or -23, or -25, or-27, or -35, overhauled with the instructions in this service bulletin to replace the new or changed part. (b)
You cannot use the existing part 65-46428-33 to replace the new or changed part. Boeing recommends that you remove the 65-46428-33 from service as given in Service Bulletin 737-57-1203. If you use the existing part 65-46428-2, or -3, or -5, or -7, or -9, or -11, or -15, or -17, or -19, or -21, or -23, or -25, or-27, or -35, you reduce the effect of the change given in this service bulletin. The existing track assembly does not have the fail safe capability of the new spares track assembly. The new spare flap track assembly for Group 2 airplanes is 65-67158-6. See 737-100/-200 AMM 27- 51-151 for removal and installation of these flap track assemblies. (c)65-46428-31, or 65C35387-4, or 65C35616-5, or 65C34812-3, or -4, or -6 (d)You can use the existing part 65C35616-5, or 65C35387-4, or 65C34812-3, or -4, or -6, overhauled with the instructions in this service bulletin to replace the new or changed part. (e)You cannot use the existing part 65-46428-31 to replace the new or changed part. Boeing recommends that you remove the 65-46428-31 from service as given in Service Bulletin 737-57-1203.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 32 of 77 **BOEING SERVICE BULLETIN 737-57A1271**See the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier data. (f) Refer to 737 Structural Repair Manual Chapter 51 for alternative fasteners. (g)It is possible, because of shim thickness, that a bolt one grip length shorter or longer can be necessary for installation of the new spares track assembly. One Washer NAS1149F0716P, or NAS1149F0732, can be used to adjust the grip length of the bolt. See Figures 8 and 9. (h)

It is possible, because of shim thickness, that a bolt one grip length shorter or longer can be necessary for installation of the new spares track assembly. One Washer NAS1149F0816P, or NAS1149F0832P, can be used to adjust the grip length of the bolt. See Figures 8 and 9. (i)

If installed on the configuration of your airplane: The removed part can be serviceable and satisfactory for installation of the new spares flap track assembly. See Figures 8 and 9. (j) A new torque-indicating washer is necessary if the wing-to-track attachment is disassembled during the inspection procedures, and for the track alignment and installation procedures given in Figures 7, 8, and 9. (k)

The retaining compound and adhesion promoter are necessary for the overhaul of a flap track. The application of the thermal spray powder (Tungsten-Carbide-Cobalt) is optional during the overhaul procedures, unless the track had Tungsten-Carbide-Cobalt applied during manufacture. Tracks that had Tungsten-Carbide-Cobalt applied during manufacture, must also have the compound applied during the overhaul procedures. See Figure 11. (l)

3. Parts Modified and Reidentified: None. 4. Parts Removed and Not Replaced: None. **D. Parts Necessary to Change Spares** None. **E. Special Tooling - Price and Availability** None. **F. Special Tooling Necessary to do this Service Bulletin** No special tools or equipment are necessary to do the change in this service bulletin. But, maintenance and overhaul tools in the manuals given in Paragraph 1.J., References, can be necessary. Examine operator tool supply to make sure all necessary tools are available.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 33 of 77 **BOEING SERVICE BULLETIN 737-57A1271**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 34 of 77 **BOEING SERVICE BULLETIN 737-57A1271**

BLANK PAGE**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 are in Structural Repair Manual 737 (SRM) 51 – Torque limits to tighten nuts and bolts are in 737 SRM 51 4. Use the approved fastener and process material substitutions in accordance with 737 SRM 51. Alternate fasteners are listed in 737 SRM 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. If the length of any fastener specified in this service bulletin does not meet the installation standards in 737 SRM 51, then a fastener of the same specification, or an approved substitute, with a length which meets the installation standards in 737 SRM 51 may be used. In addition, washers may be installed for fastener grip length in accordance with SRM Chapter 51. 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 access procedures may be required. 8. A General Visual Inspection is defined as: A visual examination of an interior or exterior area, installation or assembly to detect obvious damage, failure or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to enhance visual access to all exposed surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight or drop-light and may require removal or opening of access panels or doors. Stands, ladders or platforms may be required to gain proximity to the area being checked.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 35 of 77 **BOEING SERVICE BULLETIN 737-57A1271**9. 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. 10. Boeing Service Letter 737-SL-51-042, Damage Reporting and Repair Plan/Design Guidelines, is an acceptable procedure to request information from Boeing for additional structural repair instructions. The Service Letter describes what information must be provided to Boeing before a structural repair can be provided. 11. 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. 12. 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. 13. 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. The removed part can be discarded if a new or serviceable part is installed. 14. 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. 15. Some Boeing parts are supplied in a temporary configuration. Those parts are identified with a 'U', 'W', or 'Y' in place of the '-' (dash) in the part number. It is permitted to install parts identified with a 'U', 'W', or 'Y' as an alternative to the '-' (dash) part number. Boeing Drawing 005W0900 contains more data. **B. WORK INSTRUCTIONS INSPECTION - GROUP 1 AND GROUP 2 AIRPLANES - 737-100/200/200C**  1. Remove the forward fairing from Flap Track Position 2 (Position 7 opposite). **NOTE:** Position 2 is equivalent to Left WBL 254 and Position 7 is equivalent to Right WBL 254. 2. Refer to 737-100/200 AMM 27-51-121 and remove the center and aft fairings from Position 2 (Position 7 opposite). **NOTE:** When you disconnect the push rod from the aft flap, install a support to sufficiently hold the aft flap in a stable position during the inspection procedures. During the inspection procedures it will be necessary to extend and retract the flaps to get access to all areas of the flap track. 3. INSPECTION - TRACK WEBS AND FLANGES. Do a visual and eddy current inspection of the flap track web and flanges as shown in Figure 1.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 36 of 77 **BOEING SERVICE BULLETIN 737-57A1271**a. If damage is found in the web or on the upper and/or lower flanges of the track: (1) Make repairs as given in 737 OHM 57-53-15. (2) If the damage cannot be repaired as given in OHM 57-53-15: Replace the flap track with a serviceable flap track. Do not stop-drill cracks in the flanges of the track. Go to Step 5 for instructions for removal and installation. b. If an existing stop-drill repair is found on the upper and/or lower flanges of the track: (1) Replace the flap track with a serviceable flap track. Do not stop-drill cracks in the flanges. Go to Step 5 for instructions for removal and installation. c. If the web has an existing stop-drill repair: (1) Replace the flap track with a serviceable flap track. Do not stop-drill cracks in the web. Go to Step 5 for instructions for removal and installation. d. If you do not find damage in the flanges and/or the web, or you made repairs as given in 737 OHM 57-53-15, continue with the detail visual, ultrasonic, and eddy current inspections given in Step 4, below. e. If a flap track assembly with a short failsafe bar, part number 65-46428-31 or 65-46428-33, is found, it must be removed from service during inspection or repair. 4. INSPECTION - WITH TRACK-TO-WING ATTACHMENT ASSEMBLED. Using Figure 2, do a detail visual inspection, ultrasonic inspection, and an eddy current inspection in the area where the flap track is attached to the wing rear spar. a. If the track is loose at the attachment to the wing rear spar: Do the inspection with the track-to-wing attachment disassembled as shown in Step 5, below. b. If there are signs of damage, or corrosion, to the tapered shim and/or anti-fret strip: Do the inspection with the track-to-wing attachment disassembled as shown in Step 5, below. c. If the ultrasonic or eddy current inspection shows an indication of a crack: Do the inspection with the track-to-wing attachment disassembled as shown in Step 5, below. d. If no signs of cracks, damage, corrosion, or a loose track are found: Schedule the overhaul of the flap track at the flight cycle or in-service time given in Paragraph 1. E., Compliance 5. INSPECTION - WITH TRACK-TO-WING ATTACHMENT DISASSEMBLED. a. Refer to 737-100/200 AMM 27-51-72 and remove the trailing edge flaps. b. Refer to 737-100/200 AMM 27-51-281 and remove the flap transmission. c. Refer to 737-100/200 AMM 27-51-111 and remove the fore-flap sequencing carriage from the track. d. Remove the bolts, lower the aft end of the track, and do the inspections given in Figure 3.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 37 of 77 **BOEING SERVICE BULLETIN 737-57A1271**(1) If the anti-fret strip is discarded during the inspection: Make and install a new anti-fret strip as shown in Figure 4. Make the shop aid, shown in Figure 10, to get a satisfactory installation of the new anti-fret strip. (2) If the tapered shim is discarded during the inspection: Make and install a new tapered shim as shown in Figure 5. Make the shop aid, shown in Figure 10, to get a satisfactory installation of the new tapered shim. (3) If the steel bushing is discarded during the inspection: Make and install a new bushing as shown in Figure 6. (4) If corrosion is found on the mating surface, and/or in the bolt holes: Remove the corrosion as given in Figure 6. (5) If corrosion is found during the inspection along the outboard edge of the track flange adjacent to the outboard bolt: Make repairs as shown in the rework tables of Figure 6. If damage is too large and cannot be removed within the limits of the rework tables: Replace the flap track with a serviceable flap track. (6) If damage is found with the eddy current inspection of the outboard hole: Remove the damage as given in the eddy current inspection procedures, but make sure the hole remains in the limits given in Figure 6. If damage is too large and cannot be removed during rework in accordance with Figure 6: Replace the flap track with a serviceable flap track. e. Align and install the track as shown in Figure 7. f. Refer to 737-100/200 AMM 27-51-111 and install the fore-flap sequencing carriage. g. Refer to 737-100/200 AMM 27-51-281 and install the flap transmission. h. Refer to 737-100/200 AMM 27-51-72 and install the trailing edge flaps. 6. Refer to 737-100/200 AMM 12-20-0 and lubricate the flap track. 7. Refer to 737-100/200 AMM 27-51-121 and install the center and aft fairings at Position 2 (Position 7 opposite). 8. Install the forward fairing at Position 2 (Position 7 opposite). 9. Put the airplane back to a serviceable condition. **INSPECTION - GROUP 3 AIRPLANES - 737-300/400/500** 1. Remove the forward fairing from Flap Track Position 2 (Position 7 opposite). 2. Refer to 737-300/400/500 AMM 27-51-52 and remove the center and aft fairing from Flap Track Position 2 (Position 7 opposite).

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 38 of 77 **BOEING SERVICE BULLETIN 737-57A1271 NOTE:**  When you disconnect the push rod from the aft flap, install a support to sufficiently hold the aft flap in a stable position during the inspection procedures. During the inspection procedures it will be necessary to extend and retract the flaps to get access to all areas of the flap track. 3. INSPECTION - TRACK WEBS AND FLANGES. Do a visual and eddy current inspection of the flap track web and flanges as shown in Figure 1. a. If damage is found in the web or on the upper and/or lower flanges of the track: (1) Make repairs as given in 737 OHM 57-53-15. (2) If the damage cannot be repaired as given in OHM 57-53-15: Replace the flap track with a serviceable flap track. Do not stop-drill cracks in the flanges of the track. Go to Step 5 for instructions for removal and installation. b. If an existing stop-drill repair is found on the upper and/or lower flanges of the track: (1) Replace the flap track with a serviceable flap track. Do not stop-drill cracks in the flanges. Go to Step 5 for instructions for removal and installation. c. If the web has an existing stop-drill repair: (1) Replace the flap track with a serviceable flap track. Do not stop-drill cracks in the web. Go to Step 5 for instructions for removal and installation. d. If you do not find damage in the flanges and/or the web, or you made repairs as given in 737 OHM 57-53-15: Continue with the detail visual, ultrasonic, and eddy current inspections given in Step 4, below. e. If a flap track assembly with a short failsafe bar, part number 65-46428-31 or 65-46428-33, is found, it must be removed from service during inspection or repair. 4. INSPECTION - WITH TRACK-TO-WING ATTACHMENT ASSEMBLED. Using Figure 2, do a detail visual inspection, and an ultrasonic and eddy current inspection in the area where the flap track is attached to the wing rear spar. a. If the track is loose at the attachment to the wing rear spar: Do the inspection with the track-to-wing attachment disassembled as shown in Step 5, below. b. If there are signs of damage, or corrosion, to the tapered shim and/or anti-fret strip: Do the inspection with the track-to-wing attachment disassembled as shown in Step 5, below. c. If the ultrasonic or eddy current inspection shows an indication of a crack: Do the inspection with the track-to-wing attachment disassembled as shown in Step 5, below. d. If no signs of cracks, damage, corrosion, or a loose track are found: Schedule the overhaul of the flap track at the flight cycle or in-service time given in Paragraph 1. E., Compliance. e. If a flap track assembly with a short failsafe bar, part number 65-46428-31 or 65-46428-33, is found, it must be removed from service during inspection or repair.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 39 of 77 **BOEING SERVICE BULLETIN 737-57A1271**5. INSPECTION - WITH TRACK-TO-WING ATTACHMENT DISASSEMBLED. a. Refer to 737-300/400/500 AMM 27-51-34 and remove the trailing edge flaps. b. Refer to 737-300/400/500 AMM 27-51-71 and remove the flap transmission. c. Refer to 737-300/400/500 AMM 27-51-47 and remove the fore-flap sequencing carriage from the track. d. Remove the bolts, lower the aft end of the track, and do the inspections given in Figure 3. (1) If the anti-fret strip is discarded during the inspection: Make and install a new anti-fret strip as shown in Figure 4. Make the shop aid, shown in Figure 10, to get a satisfactory installation of the new anti-fret strip. (2) If the tapered shim is discarded during the inspection: Make and install a new tapered shim as shown in Figure 5. Make the shop aid, shown in Figure 10, to get a satisfactory installation of the new tapered shim. (3) If the steel bushing is discarded during the inspection: Make and install a new bushing as shown in Figure 6. (4) If corrosion is found on the mating surface, and/or in the bolt holes: Remove the corrosion as given in Figure 6. (5) If corrosion is found during the inspection along the outboard edge of the track flange adjacent to the outboard bolt: Make repairs as shown in the rework tables of Figure 6. If damage is too large and cannot be removed within the limits of the rework tables: Replace the flap track with a serviceable flap track. (6) If damage is found with the eddy current inspection of the outboard hole: Remove the damage as given in the eddy current inspection procedures, but make sure the hole remains in the limits given in Figure 6. If damage is too large and cannot be removed during the rework in accordance with Figure 6: Replace the flap track with a serviceable flap track. e. Align and install the track as shown in Figure 7. f. Refer to 737-300/400/500 AMM 27-51-47 and install the fore-flap sequencing carriage. g. Refer to 737-300/400/500 AMM 27-51-71 and install the flap transmission. h. Refer to 737-300/400/500 AMM 27-51-34 and install the trailing edge flaps. 6. Refer to 737-300/400/500 AMM 12-20-0 and lubricate the flap track. 7. Refer to 737-300/400/500 AMM 27-51-52 and install the center and aft fairings at Position 2 (Position 7 opposite). 8. Install the forward fairing at Position 2 (Position 7 opposite).

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 40 of 77 **BOEING SERVICE BULLETIN 737-57A1271**9. Put the airplane back to a serviceable condition. **OVERHAUL - GROUPS 1, 2, AND 3, AIRPLANES - 737-100/200/200C/300/400/500** 1. At the flight cycle or in- service time given in Paragraph 1. E.,Compliance: Refer to 737-100/200 AMM 27-51-151 and remove the flap track from the wing at Position 2 (Position 7 opposite). Refer to 737-300/400/500 AMM 27-51-49 and remove the flap track from the wing at Position 2 (Position 7 opposite). 2. Do an overhaul of the flap track as given in 737 OHM 57-53-15 and Figure 11. 3. Install an overhauled flap track at Position 2 (Position 7 opposite) as given in 737-100/200 AMM 27-51-151. Align the flap track during installation as shown in Figure 7. Install an overhauled flap track at Position 2 (Position 7 opposite) as given in 737-300/400/500 AMM 27-51-49. Align the flap track during installation as shown in Figure 7. 4. Schedule the repeat inspections and the repeat overhaul of the flap track at the flight cycles or times given in Paragraph 1. E., Compliance. 5. Put the airplane back to a serviceable condition. **REPLACEMENT - GROUP 1 AIRPLANES** 1. Refer to 737-100/200 AMM 27-51-151 and remove the flap track assembly. During removal, discard the parts shown in Figure 8. 2. Refer to 737-100/200 AMM 27-51-151 and install the new track assembly. During installation, do the alignment procedures given in Figure 7 and install the parts shown in Figure 8. 3. Put the airplane back to a serviceable condition. **REPLACEMENT - GROUP 2 AIRPLANES** 1. Replace the track assembly with an identical spares track assembly. **REPLACEMENT - GROUP 3 AIRPLANES - 737-300/400/500** 1. Refer to 737-300/400/500 AMM 27-51-49 and remove the flap track assembly. During removal, discard the parts shown in Figure 9. 2. Refer to 737-300/400/500 AMM 27-51-49 and install the new spares track assembly. During installation, do the alignment procedures given in Figure 7 and install the parts shown in Figure 9. 3. Put the airplane back to a serviceable condition.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3: February 13, 2012 41 of 77 **BOEING SERVICE BULLETIN 737-57A1271**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for one side of the airplane.

**FIGURE 1: INSPECTION - TRACK WEBS AND FLANGES (SHEET 1 OF 2)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 42 of 77 **BOEING SERVICE BULLETIN 737-57A1271 WARNING:**  MAKE SURE THAT PERSONS AND EQUIPMENT ARE CLEAR OF ALL CONTROL SURFACES BEFORE YOU SUPPLY HYDRAULIC POWER. CONTROL SURFACES CAN MOVE QUICKLY WHEN YOU SUPPLY HYDRAULIC POWER. THIS CAN CAUSE INJURY TO PERSONS AND DAMAGE TO EQUIPMENT. **WARNING:** MAKE SURE THAT PERSONS AND EQUIPMENT ARE CLEAR OF THE LEADING EDGE AND TRAILING EDGE FLAPS AND FLAP DRIVE MECHANISMS BEFORE YOU MOVE THE FLAP CONTROL HANDLE. AN ACCIDENTAL FLAP MOVEMENT CAN CAUSE INJURY TO PERSONS OR DAMAGE TO EQUIPMENT.
**NOTES QTY**  **PART NUMBER NAME**  **TASK STEP**  (a)

- - Hydraulic Power Supply 1

- - Flaps Extend/Retract

- - Hydraulic Power Remove (b) 1
- Flap Track Clean 2 (c)

- - Track Flanges Inspect 3 (d)

- - Track Webs Inspect 4 (e)

- - Eddy Current Inspection Do 5 Refer to 737-100/200 AMM 27-51-0 and supply hydraulic power. Group 3: Refer to 737-300/400/500AMM 27-51-00 and supply hydraulic power. As necessary, extend and retract the flaps during the inspection procedures to get access to all areas of the flap track. (a)
Warning: MAKE SURE TO REMOVE HYDRAULIC POWER BEFORE PERSONS GO INTO THE INSPECTION AREA. AN ACCIDENTAL FLAP MOVEMENT CAN CAUSE INJURY TO PERSONS OR DAMAGE TO EQUIPMENT. Remove loose paint, sealant, corrosion inhibiting compounds, dirt and grease from the flanges and webs of the track. Removal of the finish is not necessary, unless signs of cracks or corrosion are found during the subsequent inspections. (b)

Caution: DO NOT PRESSURE WASH THE FLAP TRACK. WATER OR SOLVENTS UNDER HIGH PRESSURE CAN GET UNDER THE FASTENER HEADS AND BETWEEN THE WEBS AND SPACER BAR. A RESULT CAN BE UNWANTED CORROSION AND CRACKS. Do a detailed visual inspection along the full length of the upper and lower flanges of the flap track. Look for stop-drill repairs, cracks, nicks, corrosion pits, galling, pieces broken off, or other signs of damage. Give special attention to the edges of the flanges. Reject a track that shows these signs of damage, or has existing stop-drill repairs. (c)

Do a detailed visual inspection along the full length of the track webs. Look for stop-drill repairs, cracks,or other signs of damage. During the inspection, give special attention to the area adjacent to the fastener countersinks in the webs. (d)
Reject tracks that have existing stop-drill repairs, and/or cracks in the web. No repair instructions are given in this service bulletin for web cracks. Do the eddy current inspection given in 737 NDT Part 6, 57-50-06. Reject a track that shows indications of cracks. (e)

**FIGURE 1: INSPECTION - TRACK WEBS AND FLANGES (SHEET 2 OF 2)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 43 of 77 **BOEING SERVICE BULLETIN 737-57A1271**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for one side of the airplane.

**FIGURE 2: INSPECTION - WITH TRACK-TO-WING ATTACHMENT ASSEMBLED (SHEET 1 OF 2)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 44 of 77 **BOEING SERVICE BULLETIN 737-57A1271 NOTES**  **QTY PART NUMBER**  **NAME TASK**  **STEP** Remove sealant sufficiently to get a clear view ofthe outer edges of the tapered shim and anti-fret strip. - - Sealant Remove 1

(a)

- - Tapered Shim Inspect 2

- - Anti-Fret Strip (b)

- - Track Attachment Inspect 3 (c)

- - Track Attachment Inspect 4 (d)

- - Track Attachment Inspect 5 (e)

- BMS 5-95 Sealant Apply 6 Do a detailed visual inspection of the tapered shim and anti-fret strip. Look for signs of movement between the components. Look to make sure the anti-fret strip is installed. Look for corrosion. (a)Do a detailed visual inspection of the area where the track is attached to the wing rear spar. Use manual force, up to 150 pounds, and try to move the track from the installed position. Look for signs of movement, cracks, and corrosion. (b)

Do the eddy current inspection given in 737 NDT Part 6, 57-50-01. Do this inspection to find cracks in the outboard edge of the track adjacent to the outboard attach bolt. (c) Do the ultrasonic inspection given in 737 NDT Part 4, 57-50-01. Do this inspection to find cracks in the inner edge of the track adjacent to the outboard attach bolt. (d)Apply around the outer edges of the tapered shim and anti-fret strip. Do not apply the sealant at this time if disassembly of the track-to-wing attachment is made necessary as given in the Paragraph 3.B., Work Instructions. (e)

**FIGURE 2: INSPECTION - WITH TRACK-TO-WING ATTACHMENT ASSEMBLED (SHEET 2 OF 2)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 45 of 77 **BOEING SERVICE BULLETIN 737-57A1271**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for one side of the airplane.

**FIGURE 3: INSPECTION - WITH TRACK-TO-WING ATTACHMENT DISASSEMBLED (SHEET 1 OF 2)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 46 of 77 **BOEING SERVICE BULLETIN 737-57A1271 NOTES**  **QTY PART NUMBER**  **NAME TASK**  **STEP** 1
- Cotter Pin Remove 1 1
- Nut Loosen 1
- Bolt Remove/Keep 2 2
- Washer 1
- Nut 1
- Bolt Remove/Keep 3 1
- Washer Remove/Discard 4 Put a support below the track to hold it in positionduring the inspection procedures. 1
- Track Lower 5

(a) 1
- Anti-Fret Strip Inspect 6 (b) 1
- Tapered Shim Inspect 7 (c) 1
- Track Attachment Inspect 8 (d) 1
- Bushing Inspect 9 (e) 1
- Track Flange Inspect 10 (f) 2
- Hole Inspect 11 Do a detailed visual inspection of the anti-fret strip. Look for signs that show the strip is loose or damaged. Discard a strip if it is made from phenolic material, or if it is loose, or if it is damaged. (a)Do a detailed visual inspection of the tapered shim. Discard a shim if it is damaged or shows signs of corrosion. Discard a shim if it is less than 1.70 inches wide as measured normal to the aft edge of the shim. Discard a shim if it is made from laminated material. (b)

Do a detailed visual inspection of the track in the area where it mates against the wing skin. Look for corrosion on the surface and corrosion in the bolt holes. Rework/overhaul a track if it shows signs of corrosion. (c)

If corrosion is found in the area where the track mates against the wing skin, do a detailed visual inspection of the bushing. Discard a bushing if there are signs of corrosion between the outer wall and track. (d)

Refer to 737 NDT Part 6, 51-00-00, Figure 24 and do an eddy current inspection on the upper surface of the track flange adjacent to the inboard and outboard bolt holes. Set the eddy current instrument frequency setting to 50 KHz to prevent false crack indications caused by scratches in the cadmium plating. Repair or replace a track that shows an indication of a crack. (e)

As an alternative to the eddy current inspection, you can do a magnetic particle inspection as given in BSOPM 20-20-01. Refer to 737 NDT Part 6, 51-00-00, Figure 19 and do an eddy current inspection of the inboard and outboard bolt holes. Repair or replace a track that shows an indication of a crack. As an alternative to the eddy current inspection, you can do a magnetic particle inspection as given in BSOPM 20-20-01. (f)

**FIGURE 3: INSPECTION - WITH TRACK-TO-WING ATTACHMENT DISASSEMBLED (SHEET 2 OF 2)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 47 of 77 **BOEING SERVICE BULLETIN 737-57A1271**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for one side of the airplane.

**FIGURE 4: REPLACEMENT - ANTI-FRET STRIP (SHEET 1 OF 2)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 48 of 77 **BOEING SERVICE BULLETIN 737-57A1271 NOTES**  **QTY PART NUMBER**  **NAME TASK**  **STEP** (a) 1 69-50772-( ) Anti-Fret Strip Remove 1

- - Thickness Measure (b) 1
- Anti-Fret Strip Make 2 Apply to all surfaces. Refer to BSOPM 20-43-03. - Type 2, Class A Chemical Conversion Coating Apply one layer to all surfaces.

- BMS 10-11, Type I Primer (c)

- - Surface Clean 3 Apply to all bare aluminum. Refer to BSOPM 20-43-03. - Type 2, Class A Chemical Conversion Coating Apply

Two layers.

- BMS 10-11, Type I Primer To mating surface of new anti-fret strip. - BMS 5-95 Sealant Apply 4

1
- Anti-Fret Strip Install 1
- Pressure Plate Install 5 2
- Temporary Fasteners Install 6 (d)

- - Torque Apply 7 2
- Temporary Fasteners Remove 8 1
- Pressure Plate Apply a bead around the edges of the strip. - BMS 5-95 Sealant Apply 9

Remove the damaged anti-fret strip and measure the thickness. The new replacement strip must have the same thickness as the removed strip. (a)Make from 7075-T6 Aluminum Alloy Sheet, AMS-QQ-A-250/12. (b)Clean and remove all signs of enamel paint from the wing lower surface in the wing-to-track attachment area. Refer to BSOPM 20-30-02. (c)Apply 360-420 inch-pound. Give the sealant sufficient time to cure before you continue with the subsequent step. (d)

**FIGURE 4: REPLACEMENT - ANTI-FRET STRIP (SHEET 2 OF 2)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 49 of 77 **BOEING SERVICE BULLETIN 737-57A1271**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for one side of the airplane.

**FIGURE 5: REPLACEMENT - TAPERED SHIM (SHEET 1 OF 2)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 50 of 77 **BOEING SERVICE BULLETIN 737-57A1271 NOTES**  **QTY PART NUMBER**  **NAME TASK**  **STEP** (a) 1 65-46429-( ), 69- 50772-( ) or 69- 77633 Tapered Shim Remove 1

- - Thickness Measure (b) 1
- Tapered Shim Make 2 Apply to all surfaces. Refer to BSOP 20-43-03. - Type 2, Class A Chemical Conversion Coating Apply one layer to all surfaces.

- BMS 10-11, Type I Primer (c)

- - Surface Clean 3 Two layers.

- BMS 10-11, Type I Primer To mating surface of new tapered shim. - BMS 5-95 Sealant Apply 4

1
- Tapered Shim Install 1
- Pressure Plate Install 5 2
- Temporary Fasteners Install 6 (e) 2
- Self-Aligning Washer 360-420 inch-pound.

- - Torque Apply 7 (d)

- - Torque Apply 8 2
- Temporary Fasteners Remove 9 1
- Pressure Plate Apply a bead around the edges of the shim. - BMS 5-95 Sealant Apply 10

Remove the rejected shim and measure the thickness. The new replacement shim must have the same thickness as the removed shim, unless corrosion was removed from the upper surface of the track. If corrosion was removed from the track, increase the thickness of the new shim to adjust for the change in the thickness of the track. If you do not know the correct thickness of the new shim, refer to 737-100/200 AMM 27-51-151 for Group 1 and Group 2 Airplanes, and 737-300/400/500 AMM 27- 51-49 for Group 3 Airplanes. (a)

Make from 2024-T351 Aluminum Alloy Plate, or Sheet, AMS-QQ-A-250/12. The thickness at all points along the aft edge of the shim must not be less than 0.03 inches. (b)Clean and remove all signs of enamel paint from the mating surface of the track. Refer to BSOPM 20- 30-02. (c)Apply 400-460 inch-pounds. Give the sealant sufficient time to cure before you continue with the subsequent step. (d)The two holes are not perpendicular to the surfaces of the tapered shim. To get a satisfactory pressure during the torque procedure, use self-aligning washers. (e)

**FIGURE 5: REPLACEMENT - TAPERED SHIM (SHEET 2 OF 2)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 51 of 77 **BOEING SERVICE BULLETIN 737-57A1271 FIGURE 6: TRACK REPAIRS AND BUSHING REPLACEMENT**  **(SHEET 1 OF 5)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 52 of 77 **BOEING SERVICE BULLETIN 737-57A1271 FIGURE 6: TRACK REPAIRS AND BUSHING REPLACEMENT**  **(SHEET 2 OF 5)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 53 of 77 **BOEING SERVICE BULLETIN 737-57A1271 Rework Table 1 - Flap Track 65-46427-4** 
**MAXIMUM ALLOWABLE HOLE DIAM ETERS**  **MINIMUM ALLOWABLE DIMENSIONS**
**d3 d2**  **d1 W**  **T4 (a) T3 (a)**  **T2 (a) T1 (a)**  0.5835 0.6855 0.5835 4.270 0.380 0.235 0.380 0.235 **Rework Table 2 - Flap Tracks 65-46427-5/-7/-11/-13/-17/-21/-23/-25/-27/-29/-31/-44/-46 & 65C35380-2**
**MAXIMUM ALLOWABLE HOLE DIAM ETERS**  **MINIMUM ALLOWABLE DIMENSIONS**
**d3 d2**  **d1 W**  **T4 (a) T3 (a)**  **T2 (a) T1 (a)**  0.5835 0.6855 0.5835 4.270 0.340 0.195 0.340 0.195 **Rework Table 3 - Flap Tracks 65-67156-2/-12/-14**
**MAXIMUM ALLOWABLE HOLE DIAM ETERS**  **MINIMUM ALLOWABLE DIMENSIONS**
**d3 d2**  **d1 W**  **T4 (a) T3 (a)**  **T2 (a) T1 (a)**  0.5835 0.6855 0.5835 4.270 0.348 0.208 0.348 0.208 **Rework Table 4 - Flap Tracks 65-46427-35/-39**
**MAXIMUM ALLOWABLE HOLE DIAM ETERS**  **MINIMUM ALLOWABLE DIMENSIONS**
**d3 d2**  **d1 W**  **T4 (a) T3 (a)**  **T2 (a) T1 (a)**  Do Not Rework - Remove from service if damaged **Rework Table 5 - Flap Tracks 65C34809-2 & 65C35387-2 & 65C35616-3**
**MAXIMUM ALLOWABLE HOLE DIAM ETERS**  **MINIMUM ALLOWABLE DIMENSIONS**
**d3 d2**  **d1 W**  **T4 (a) T3 (a)**  **T2 (a) T1 (a)**  0.5835 0.6855 0.5835 4.270 0.340 0.195 0.340 0.195

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for one side of the airplane.

**FIGURE 6: TRACK REPAIRS AND BUSHING REPLACEMENT (SHEET 3 OF 5)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 54 of 77 **BOEING SERVICE BULLETIN 737-57A1271 NOTES**  **QTY PART NUMBER**  **NAME TASK**  **STEP** (a)

- - Corrosion Remove 1 (b)

- - Repair Area Measure 2 (c) 1 69-37234-( ) Bushing Remove 3 (d) 1
- Hole Inspect 4

- - Diameter Increase

- - Diameter Measure Shot peen the holes as given in BSOPM 20-10-03, Intensity.012A, Coverage 2.0. 1
- Hole Shot peen Apply cadmium-titanium alloy plating to the holes as given in BSOPM 20-42-02. - - Plating Apply (e) 2
- Hole Inspect 5

- - Diameter Increase

- - Diameter Measure Shot peen the holes as given in BSOPM 20-10-03, Intensity.012A, Coverage 2.0. 2
- Hole Shot peen Apply cadmium-titanium alloy plating to the holes as given in BSOPM 20-42-02. - - Plating Apply Shot peen all surfaces of the repair areaas given in BSOPM 20-10-03, Intensity.012A, Coverage 2.0. - - Repair Area Shot peen 6

Apply cadmium-titanium alloy plating to all surfaces of the repair area as given in BSOPM 20-42-02. - - Plating Apply 7

(f) 1
- Repair Bushing Make 8

- - Plating Apply Install bushing wet with sealant.

- BMS 5-95 Sealant Apply 9 (g) 1
- Repair Bushing Install If corrosion was found during the inspection, refer to the track repair procedures given in the 737 OHM 57-53-15 and BSOPM 20-10-01, and remove the damaged material from the repair area of the track. Maintain flatness of the repaired surface. (a)

Measure the width (W) of the track in the repair area. Measure the thickness (T) of the track in the repair area at the four locations shown. Do not include the thickness of the tapered shim. (b)If the width and thickness are in the limits shown in the tables: Continue with the inspection of the bushing. - If the width and thickness are not in the limits shown in the tables: Write to Boeing for repair instructions.

-

**FIGURE 6: TRACK REPAIRS AND BUSHING REPLACEMENT (SHEET 4 OF 5)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 55 of 77 **BOEING SERVICE BULLETIN 737-57A1271**Refer to BSOPM 20-50-03 and remove the bushing if it was rejected during the inspection. (c)Note: It can be necessary to remove the tapered shim before you remove the bushing. To remove the tapered shim use a heat gun to make the sealant soft, and then use steel lockwire to cut the sealant between the lower surface of the shim and the track. Find and record the thickness of the tapered shim before removal. To find the shim thickness do one of these procedures: — Measure the shim thickness before removal. — Refer to the thickness that is recorded on the decal bonded to the wing rear spar adjacent to the flap track. — Use the procedure given in 737-100/200 AMM 27-51-151 for Group 1 and Group 2 Airplanes and 737-300/400/500 AMM 27-51-49 for Group 3 Airplanes. Note: The anti-fret strip must be installed if you use the AMM procedure to find the shim thickness. Do a detailed visual inspection of the hole. Look for signs of corrosion. (d)If corrosion is found: Increase the hole diameter, as given in BSOPM 20-10-01, to remove corrosion. Make and install a repair bushing. Hole diameter, before bushing installation, must remain in the limits shown in the tables. -
Do a detailed visual inspection of the d1 and d3 holes. Look for signs of corrosion. (e)— If corrosion is found: Increase the hole diameters as given in BSOPM 20-10-01 to remove the corrosion. Hole diameters must remain in the limits shown in the rework tables. Make the bushing from 15-5PH or 17-4PH 180-200 ksi Steel Bar, AMS 5643, as shown in the 737 OHM 57-53-15. Use the dimensions shown in this service bulletin illustration. The outer diameter (OD) must be 0.0015 - 0.0017 inches larger than the diameter of the hole. Apply cadmium plating to all surfaces of the bushing as given in BSOPM 20-42-05, Finish Code F-15.02. (f)

Refer to BSOPM 20-50-03 and install the bushing with the shrink fit procedure. Make sure the bushing does not protrude above the upper surface of the track, within 0.000/ -0.003 inches. (g)

**FIGURE 6: TRACK REPAIRS AND BUSHING REPLACEMENT (SHEET 5 OF 5)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 56 of 77 **BOEING SERVICE BULLETIN 737-57A1271 FIGURE 7: ALIGNMENT - TRACK INSTALLATION**  **(SHEET 1 OF 6)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 57 of 77 **BOEING SERVICE BULLETIN 737-57A1271 FIGURE 7: ALIGNMENT - TRACK INSTALLATION**  **(SHEET 2 OF 6)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 58 of 77 **BOEING SERVICE BULLETIN 737-57A1271**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for one side of the airplane.

**FIGURE 7: ALIGNMENT - TRACK INSTALLATION (SHEET 3 OF 6)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 59 of 77 **BOEING SERVICE BULLETIN 737-57A1271 NOTES**  **QTY PART NUMBER**  **NAME TASK**  **STEP** (a) 1
- Alignment Pin Make 1 1
- Alignment Pin Install (b) 1
- Flap Track Lift/Align/Hold 2 Apply to the shank and threads of the bolt. - MIL-C-11796, Class 3 Compound Apply 3 (c) 1 BACB30LE7HU( ) or BACB30LE7HK( ) Bolt Install (c) Under bolt head. 1 BACW10AK-C7 or BACW10BN7SC Washer (c) Under nut. 1 or 2 NAS1149F0716P or AN960-716L Washer (c) 1 BACN10HR7C or BACN10HR7CD or BACN10B7L Nut

Temporarily tighten the nut to 40-60 pound-inch. - - Torque Apply 4 Temporarily tighten thenut to 270-300 poundinch. - - Torque Apply 5

Temporarily tighten thenut to 360-420 poundinch. - - Torque Apply 6

(d)

- - Alignment Pin Inspect 7 1
- Alignment Pin Remove 8 Decrease the torque to 40-60 pound-inch. 1
- Nut Loosen 9 Decrease the torque to 40-60 pound-inch. 1
- Nut Loosen 10 (c) 1 NAS577-8A or NAS577B8A Barrel Nut Install 11

1 NAS578-8A Retainer

- MIL-C-11796, Class 3 Compound Apply (c) 1 BACB30LE8H( ) or BACB30LE8HU( ) or BACB30LE8HK( ) Bolt Install

(e) 1 BACW10DN8 Washer - Torque-In- dicating

**FIGURE 7: ALIGNMENT - TRACK INSTALLATION (SHEET 4 OF 6)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 60 of 77 **BOEING SERVICE BULLETIN 737-57A1271 NOTES**  **QTY PART NUMBER**  **NAME TASK**  **STEP** Temporarily tighten the bolt to 40-60 pound-inch - - Torque Apply Tighten nut to 270 - 300 pound-inch. - - Torque Apply 12 (f) 1 MS24665-285 Cotter Pin Install Tighten nut to 360 - 420 pound-inch. (h) - - Torque Apply 13 Cation: DURING THE INSTALLATION OF THE INBOARD ATTACH BOLT, MAKE SURE THAT THE SHANK OF THE BOLT DOES NOT TOUCH AGAINST THE THREADS OF THE BARREL NUT. IF THE SHANK OF THE BOLT TOUCHES THE THREADS OF THE BARREL NUT, THE FLAP TRACK WILL NOT BE HELD WITH SUFFICIENT FORCE TO PREVENT MOVEMENT DURING FLIGHT. MOVEMENT DURING FLIGHT CAN DAMAGE THE TRACK, ATTACH BOLTS, AND MATING STRUCTURE. (g)

- - Torque Apply 14 Refer to BSOPM 20-50- 02. - MS20995C32, or MS20995N32, or MS20995F41 Lockwire Install 15

Apply a bead around the heads of the bolts. - BMS 5-95 Sealant Apply 16 Apply a bead around the edges of the tapered shim and anti-fret strip. - BMS 5-95 Sealant Apply 17

Make from steel. Diameter 0.4990 inch (+0.0005 to -0.0000). Length as necessary to extend through track. (a)Lift the track up until it engages the alignment pin and touches firmly against the wing skin. Hold the track in position until the bolt is installed. (b)Use the components that were removed from your airplane to do the installation of a track that was disassembled for inspection, or for the installation of a repaired or overhauled track. (c)Use the components shown in Figure 8 for the installation of a New Spares Track Assembly 65-46428-36. Use the components shown in Figure 9 for the installation of a New Spares Track Assembly 65C34812-8. Apply a light force and try to turn the pin in the hole and move the pin up and down in the hole. Look for easy movement of the pin. If the pin moves easily the track is aligned correctly. If the pin does not move easily, do the steps below: (d)

Decrease the torque on the forward attach bolt to 40-60 pound-inch 1. Remove the outboard attach bolt and lower the aft end of the track down to a support. 2. Caution: DO NOT INCREASE THE INNER DIAMETER OF THE STEEL BUSHING AT THE INBOARD ATTACH BOLT. A RESULT OF AN INCREASED DIAMETER AT THIS LOCATION CAN BE A LOOSE TRACK. A LOOSE TRACK CAN MOVE DURING FLIGHT AND DAMAGE THE TRACK, ATTACH BOLTS, AND MATING STRUCTURE.

**FIGURE 7: ALIGNMENT - TRACK INSTALLATION (SHEET 5 OF 6)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 61 of 77 **BOEING SERVICE BULLETIN 737-57A1271**Increase the inner diameter of the aluminum bushing in the inboard attach hole in the wing skin and aft track support fitting to 0.5015 inch maximum. 3. Apply a chemical conversion coating to the inner surface of the bushing as given in BSOPM 20-43- 03. 4. Install the 0.4990 (+0.0005 to -0.0000) diameter alignment pin in the inboard hole. 5. Lift the track up until it engages the alignment pin and touches against the wing skin. 6. Install the outboard attach bolt and apply a torque of 40-60 inch-pound to the nut. 7. Remove the alignment pin. 8. Apply a 270-300 pound-inch torque on the nut of the forward attach bolt. 9. Apply a 360-420 pound-inch torque on the nut of the outboard attach bolt. 10. Install the alignment pin in the inboard attach hole. If the pin moves easily the track is aligned correctly. If the pin does not move easily, do these steps, 1 through 11, again, or write to Boeing for instructions. 11. Install a new torque-indicating washer. Make sure to put the special countersink washer, that is a component of the new torque-indicating washer, against the bolt head. (e)If there is a castellated nut on the forward attach bolt, install a cotter pin. (f) Tighten the bolt until the torque-indicating washer does not turn. Maximum torque permitted is 1,300 poundinch. Make sure one full thread on the bolt extends through the nut. (g)If the outer ring of the torque-indicating washer continues to turn at 950 pound-inch, or more, of torque; it is possible that the track installation has one or more of these conditions: The shank of the bolt is too long and bottoms out against the nut. If the bolt shank is too long, install one or two Washers BACW10AKP8 under the torque-indicating washer. -
There is too much sealant in the bolt hole. Remove the bolt and remove the unwanted sealant.

- The track is not aligned correctly. Do the alignment procedures again, or contact Boeing for instructions.

- Make sure that the bolt protrudes from the nut by a minimum of one thread and that the nut does not bottom out on the thread run-out. If a bottoming out condition exists, add an extra washer under the nut or bolt head. Additionally, the bolt length may be adjusted two grip lengths longer or shorter. (h)

**FIGURE 7: ALIGNMENT - TRACK INSTALLATION (SHEET 6 OF 6)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 62 of 77 **BOEING SERVICE BULLETIN 737-57A1271 FIGURE 8: INSTALLATION - NEW SPARES TRACK - GROUP 1 AIRPLANES - 737-100/200**  **(SHEET 1 OF 5)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 63 of 77 **BOEING SERVICE BULLETIN 737-57A1271 FIGURE 8: INSTALLATION - NEW SPARES TRACK - GROUP 1 AIRPLANES - 737-100/200**  **(SHEET 2 OF 5)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 64 of 77 **BOEING SERVICE BULLETIN 737-57A1271**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for one side of the airplane. **NOTE:** Refer to 737 AMM 27-51-151 for track removal and installation procedures.
**NOTES QTY**  **PART NUMBER NAME**  **TASK STEP**  (a) 1 MS24665-285 Cotter Pin Remove/Discard 1 (a) 1 BACN10HR7C Nut Remove/Discard (a) 1 AN310-7 Nut (a) 1 BACN10JD107 Nut Remove/Keep 1 MS20002-7 Washer 1 MS20002-C7 Washer (a) 1 BACB30LM7DU17 Bolt Remove/Discard (a) 1 BACB30NM7DK( ) Bolt (a) 1 66-23210-6 Sleeve (a) 1 66-23210-1 Sleeve Remove/Keep (a) 1 BACN10B7L Nut Remove/Discard 2 (a) 1 BACN10HR7C Nut (a) 1 BACN10HR7CD Nut Remove/Keep 1 AN960-716L Washer Remove/Keep 3 1 BACW10AK-C7 Washer Remove/Discard 4 1 BACB30LE7HU( ) Bolt Remove/Discard 5 1 BACB30LE8HU( ) Bolt Remove/Discard 6 (a) 1 BACW10AK-C8 Washer Remove/Discard 7 (a) 1 BACW10DN8 Washer Remove/Discard 1 NAS577-8A Barrel Nut Remove/Discard 8 1 NAS578-8A Retainer Remove/Keep (b) 1 65-46428-( ) Flap Track Assy Remove 9Caution: MAKE SURE TO ALIGN THE NEW TRACK CORRECTLY DURING INSTALLATION. AN INCORRECTLY ALIGNED TRACK CAN MOVE DURING FLIGHT. MOVEMENT DURING FLIGHT CAN DAMAGE THE TRACK, ATTACH BOLTS, AND MATING STRUCTURE.

**FIGURE 8: INSTALLATION - NEW SPARES TRACK - GROUP 1 AIRPLANES - 737-100/200 (SHEET 3 OF 5)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 65 of 77 **BOEING SERVICE BULLETIN 737-57A1271 NOTES**  **QTY PART NUMBER**  **NAME TASK**  **STEP** Refer to Figure 7 for alignment and torqueprocedures during the installation of the new flap track. 1 65-46428-36 Flap Track Assy Install/Align 10

1 66-23210-1 Sleeve Install 11 1 BACB30LT7DU17 Bolt 1 BACW10BP7C Washer 1 BACW10BP7P Washer 1 BACN10JD107 Nut Apply to shank and threads of bolt - MIL-C-11796, Class 3 Compound Apply 12 1 BACB30LE7HK26 Bolt Install 1 BACW10BP7CD Washer Install 13 AN960-716L is optional. 1 or 2 NAS1149F0732P Washer Install 14 1 BACN10HR7CD Nut Install 15 1 NAS578-8A Retainer Install 16 1 NAS577B8A Barrel Nut 1 BACW10DN8 Washer Install 17 Apply to shank and threads of bolt - MIL-C-11796, Class 3 Compound Apply 18 1 BACB30LE8HK31 Bolt Install (c) AN960-716L or AN960-716 optional 1 NAS1149F0763P or NAS1149F0732P Washer Install 19

1 MS24665-285 Cotter Pin Refer to BSOPM 20-50- 02. - NASM20995C32, or NASM20995N32 Lockwire Install 20 Apply a bead around the heads of the bolts. - BMS 5-95 Sealant Apply 21 Apply a bead around the edges of the tapered shim and anti-fret strip. - BMS 5-95 Sealant Apply 22

This part is not installed on all airplanes. Keep or discard the part that is applicable to your airplane. (a)Remove a 65-46428-2, or -3, or -5, or -7, or -9, or -11, or -15, or -17, or -19, or -21, or -23, or -25, or27, or -33. (b)

**FIGURE 8: INSTALLATION - NEW SPARES TRACK - GROUP 1 AIRPLANES - 737-100/200 (SHEET 4 OF 5)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 66 of 77 **BOEING SERVICE BULLETIN 737-57A1271**If necessary, install one of these washers between the nut and Washer BACW10BP7P to get the correct alignment of the nut for installation of the cotter pin. (c)

**FIGURE 8: INSTALLATION - NEW SPARES TRACK - GROUP 1 AIRPLANES - 737-100/200 (SHEET 5 OF 5)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 67 of 77 **BOEING SERVICE BULLETIN 737-57A1271 FIGURE 9: INSTALLATION - NEW SPARES TRACK - GROUP 3 AIRPLANES - 737-300/400/500**  **(SHEET 1 OF 4)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 68 of 77 **BOEING SERVICE BULLETIN 737-57A1271 FIGURE 9: INSTALLATION - NEW SPARES TRACK - GROUP 3 AIRPLANES - 737-300/400/500**  **(SHEET 2 OF 4)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 69 of 77 **BOEING SERVICE BULLETIN 737-57A1271**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for one side of the airplane. **NOTE:** Refer to 737 AMM 27-51-49 for track removal and installation procedures.
**NOTES QTY**  **PART NUMBER NAME**  **TASK STEP**  1 MS24665-285 Cotter Pin Remove/Discard 1 1 BACN10JD107 Nut Remove/Keep (a) 1 AN960-716L Washer (a) 1 AN960-716 Washer 1 BACB30LT7DU27 Bolt 1 66-23210-1 Sleeve 1 BACN10HR7CD Nut Remove/Keep 2 1 AN960-716L Washer Remove/Keep 3 (a) 1 BACW10BN7SC Washer Remove/Keep 4 (a) 1 BACW10BP7CD Washer Remove/Discard (a) 1 BACW10AK-C7 Washer (a) 1 BACB30LE7HU( ) Bolt Remove/Discard 5 (a) 1 BACB30LE7HK26 Bolt Remove/Keep (a) 1 BACB30LE8HU( ) Bolt Remove/Discard 6 (a) 1 BACB30LE8HK31 Bolt Remove/Keep 1 BACW10DN8 Washer Remove/Discard 7 1 NAS577B8A Barrel Nut Remove/Keep 8 1 NAS578-8A Retainer (d) 1 (b) Flap Track Assy Remove 9Caution: MAKE SURE TO ALIGN THE NEW TRACK CORRECTLY DURING INSTALLATION. AN INCORRECTLY ALIGNED TRACK CAN MOVE DURING FLIGHT. MOVEMENT DURING FLIGHT CAN DAMAGE THE TRACK, ATTACH BOLTS, AND MATING STRUCTURE. Refer to Figure 7 for alignment and torqueprocedures during the installation of the new flap track. 1 65C34812-8 Flap Track Assy Install/Align 10

**FIGURE 9: INSTALLATION - NEW SPARES TRACK - GROUP 3 AIRPLANES - 737-300/400/500 (SHEET 3 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 70 of 77 **BOEING SERVICE BULLETIN 737-57A1271 NOTES**  **QTY PART NUMBER**  **NAME TASK**  **STEP** 1 66-23210-1 Sleeve Install 11 1 BACB30LT7DU27 Bolt 1 BACW10BP7C Washer 1 BACW10BP7P Washer 1 BACN10JD107 Nut Apply to shank and treads of bolt - MIL-C-11796, Class 3 Compound Apply 12 BACB30LE7HK26 Bolt Install 1 BACW10BN7SC Washer Install 13 AN960-716L is optional. 1 or 2 NAS1149F0732P Washer Install 14 1 BACN10HR7CD Nut Install 15 1 NAS578-8A Retainer Install 16 1 NAS577B8A Barrel Nut 1 BACW10DN8 Washer Install 17

- MIL-G-23827 Grease Apply 18 1 BACB30LE8HK31 Bolt Install (c) AN960-716L or AN960-716 optional 1 NAS1149F0716P or NAS1149F0732P Washer Install 19

1 MS24665-285 Cotter Pin Refer to BSOPM 20-50- 02. - MS20995C32, or MS20995N32, or MS20995F41 Lockwire Install 20

Apply a bead around the heads of the bolts. - BMS 5-95 Sealant Apply 21 Apply a bead around the edges of the tapered shim and anti-fret strip. - BMS 5-95 Sealant Apply 22

This part is not installed on all airplanes. Keep or discard the part that is applicable to your airplane. (a)65-46428-31, or 65C35387-4, or 65C35616-5, or 65C34812-3, or -4, or -6 (b)If necessary, install one of these washers between the nut and Washer BACW10BP7P to get the correct alignment of the nut for installation of the cotter pin. (c)You can use the existing part 65C35616-5, or 65C35387-4, or 65C34812-3, or -4, or -6, overhauled with the instructions in this service bulletin to replace the new or changed part. (d)You cannot use the existing part 65-46428-31 to replace the new or changed part.

**FIGURE 9: INSTALLATION - NEW SPARES TRACK - GROUP 3 AIRPLANES - 737-300/400/500 (SHEET 4 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 71 of 77 **BOEING SERVICE BULLETIN 737-57A1271**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for one side of the airplane.
**NOTES QTY**  **PART NUMBER NAME**  **TASK STEP**  (a) 2
- Shop Aid Make 1 Make from any Aluminum Plate, or equivalent material. (a)

**FIGURE 10: SHOP AID - PRESSURE PLATE (SHEET 1 OF 1)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 72 of 77 **BOEING SERVICE BULLETIN 737-57A1271 FIGURE 11: TRACK OVERHAUL - SUPPLEMENTAL INSTRUCTIONS TO OHM 57-53-15**  **(SHEET 1 OF 5)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 73 of 77 **BOEING SERVICE BULLETIN 737-57A1271 FIGURE 11: TRACK OVERHAUL - SUPPLEMENTAL INSTRUCTIONS TO OHM 57-53-15**  **(SHEET 2 OF 5)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 74 of 77 **BOEING SERVICE BULLETIN 737-57A1271 FIGURE 11: TRACK OVERHAUL - SUPPLEMENTAL INSTRUCTIONS TO OHM 57-53-15**  **(SHEET 3 OF 5)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 75 of 77 **BOEING SERVICE BULLETIN 737-57A1271 Table 1- Flap Track 65-46427-4** 
**MAXIMUM ALLOWABLE HOLE DIAM ETERS**  **MINIMUM ALLOWABLE DIMENSIONS**
**d3 d2**  **d1 W**  **T4 (a) T3 (a)**  **T2 (a) T1 (a)**  0.5835 0.6855 0.5835 4.270 0.380 0.235 0.380 0.235 **Table 2 - Flap Tracks 65-46427-5/-7,/-11/-13/-17/-21/-23/-25/-27 -29 -31/-44/-46/ & 65C35380-2**
**MAXIMUM ALLOWABLE HOLE DIAM ETERS**  **MINIMUM ALLOWABLE DIMENSIONS**
**d3 d2**  **d1 W**  **T4 (a) T3 (a)**  **T2 (a) T1 (a)**  0.5835 0.6855 0.5835 4.270 0.340 0.195 0.340 0.195 **Table 3 - Flap Tracks 65-67156-2/-12/-14**
**MAXIMUM ALLOWABLE HOLE DIAM ETERS**  **MINIMUM ALLOWABLE DIMENSIONS**
**d3 d2**  **d1 W**  **T4 (a) T3 (a)**  **T2 (a) T1 (a)**  0.5835 0.6855 0.5835 4.270 0.348 0.208 0.348 0.208 **Table 4 - Flap Tracks 65-46427-35/-39**
**MAXIMUM ALLOWABLE HOLE DIAM ETERS**  **MINIMUM ALLOWABLE DIMENSIONS**
**d3 d2**  **d1 W**  **T4 (a) T3 (a)**  **T2 (a) T1 (a)**  Do Not Rework - Remove from Service **Table 5 - Flap Tracks 65C34809-2 & 65C35387-2 & 65C35616-3**
**MAXIMUM ALLOWABLE HOLE DIAM ETERS**  **MINIMUM ALLOWABLE DIMENSIONS**
**d3 d2**  **d1 W**  **T4 (a) T3 (a)**  **T2 (a) T1 (a)**  0.5835 0.6855 0.5835 4.270 0.340 0.195 0.340 0.195 The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for one side of the airplane. **NOTE:** During the overhaul of a flap track assembly, as given in OHM 57-53-15, do the three work steps below.

**FIGURE 11: TRACK OVERHAUL - SUPPLEMENTAL INSTRUCTIONS TO OHM 57-53-15 (SHEET 4 OF 5)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 76 of 77 **BOEING SERVICE BULLETIN 737-57A1271 NOTES**  **QTY PART NUMBER**  **NAME TASK**  **STEP** (a)

- - Tables 1, 2, 3, 4, 5 Refer To 1 (b) (c) Apply the finish as given in BSOPM 20-10-05, except as noted in note (c) below and view C in this figure. Thickness 0.004 - 0.006. Class 2: Cobalt composition to be a minimum of 15 percent by weight. Class 4: Surface roughness as shown. - BMS 10-67, Type I, Class 2 or Class 4 Finish Apply 2

Apply to bolt threads and tapped hole at 23 locations. Apply Locquic Primer N 7649 to the threads and tapped hole before you apply Loctite 262. To apply MIL-S-46163, refer to BSOPM 20-50- 12. - Loctite 262 or MIL-S-46163, Type II, Grade O Retaining Compound Apply 3

Apply the sealant to the countersink and counterbore. - BMS 5-95 Sealant

During the OHM 57-53-15 overhaul procedures: Refer to Tables 1 through 5 of this figure for the minimum track thickness, and maximum hole diameter, in the track attachment area. Minimum track thickness refers to the track thickness after the removal of corrosion during the overhaul procedures. (a)

Application of this Tungsten Carbide-Cobalt finish is optional, however, fatigue tests and service experience shows that the Tungsten Carbide-Cobalt finish can help prevent corrosion damage. With this finish applied, roller wear coating failure occurs within the coating itself (cohesive), thereby leaving a thin (protective) coating remaining on the 4340M surface after failing. This is unlike the current failure mode with standard finishes, which yields an adhesive failure (primer to 4340M substrate) leaving the surface unprotected to the corrosive elements. (b)

Note: Application of this finish is not optional on flap tracks that had Tungsten Carbide-Cobalt applied during manufacture. Thermal Spray Coating shall not terminate with a square edge, but shall taper from full to zero thickness over a minimum length of 0.006 inches. The tapered edge of the coating shall be contained within a0.080 inch (wide) band as shown. This band shall start at a tangent point of a shoulder, chamfer, undercut, hole, keyway or similar feature of the part being coated. (c)

**FIGURE 11: TRACK OVERHAUL - SUPPLEMENTAL INSTRUCTIONS TO OHM 57-53-15 (SHEET 5 OF 5)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 11, 2003 737-57A1271 Revision 3 February 13, 2012 77 of 77 **BOEING SERVICE BULLETIN 737-57A1271**