# Boeing Alert Service Bulletin 737-57A1302: Revision 1

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- Document: [Boeing Alert Service Bulletin 737-57A1302](https://openairdocs.org/service-documents/boeing/737-57a1302.md)
- Title as filed: U.S. DOT/FAA - Service Bulletin
- Pages: 42
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## Text

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### Page 1

Commercial 
Airplanes
737
Service Bulletin
Number: 737-57A1302
Original Issue: December 15, 2008
Revision 1: October 18, 2010
ATA System: 5754
SUBJECT: WINGS - Leading Edge Slats- Main Track Down Stop Modification and Detailed
Inspection
Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15
CFR 730-774). An export license may be required before it is used for development, production or use by foreign
persons from specific countries. The controller of this data has the individual responsibility to abide by all export
laws.
9E991ECCN:
BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET
Copyright © 2008 The Boeing Company
Unpublished Work - All Rights Reserved
Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable
subject matter. Boeing also claims copyright in this document as a compilation and/or collective work.
This document includes proprietary information owned by The Boeing Company and/or one or more third parties.
Treatment of the document and the information it contains is governed by contract with Boeing. For more
information, contact The Boeing Company, P.O. Box 3707, Seattle, Washington 98124.
Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, Dreamliner,
BBJ, DC-8, DC-9, DC-10, KC-10, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8A, Poseidon and the
Boeing livery are all trademarks owned by The Boeing Company; and no trademark license is granted in
connection with this document unless provided in writing by Boeing.
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7.0

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Table of Contents
Revision Transmittal Sheet ............................................ 5
Summary ...................................................... 7
1. PLANNING INFORMATION ........................................ 1 1
A. Effectivity ............................................... 1 1
1. Airplanes ............................................ 1 1
2. Spares Affected ........................................ 2 0
B. Concurrent Requirements ...................................... 2 0
C. Reason ................................................ 2 1
D. Description .............................................. 2 2
E. Compliance .............................................. 2 2
F. Approval ............................................... 2 3
G. Manpower .............................................. 2 3
H. Weight and Balance Changes .................................... 2 4
I. Electrical Load Data ......................................... 2 4
J. References .............................................. 2 4
1. Existing Data .......................................... 2 4
2. Data supplied with this Service Bulletin ............................ 2 4
3. Installation Drawings Used in the Preparation of this Service Bulletin ............ 2 4
K. Publications Affected ........................................ 2 5
L. Interchangeability and Intermixability of Parts ........................... 2 5
2. MATERIAL INFORMATION ........................................ 2 7
A. Material - Price and Availability ................................... 2 7
B. Industry Support Information .................................... 2 7
C. Parts Necessary For Each Airplane ................................. 2 7
1. Kits/Parts ............................................ 2 7
2. Parts and Materials Supplied by the Operator ........................ 2 8
3. Parts Modified and Reidentified ................................ 2 8
4. Parts Removed and Not Replaced .............................. 2 8
D. Parts Necessary to Change Spares ................................. 2 8
E. Special Tooling - Price and Availability ............................... 2 9
F. Special Tooling Necessary to do this Service Bulletin ....................... 2 9
3. ACCOMPLISHMENT INSTRUCTIONS .................................. 3 1
A. GENERAL INFORMATION ..................................... 3 1
B. WORK INSTRUCTIONS ....................................... 3 1
FIGURE 1: SHRINK-FIT BUSHING INSTALLATION ........................... 3 5
FIGURE 2: SHRINK-FIT BUSHING REAMING .............................. 3 6
FIGURE 3: SLAT MAIN TRACK DOWN STOP AND AFT SIDE GUIDE MODIFICATION ....... 3 7
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Commercial 
Airplanes
737
Service Bulletin
Revision Transmittal SheetNumber: 737-57A1302Original Issue: December 15, 2008
Revision 1: October 18, 2010
ATA System: 5754
SUBJECT: WINGS - Leading Edge Slats- Main Track Down Stop Modification and Detailed
Inspection
This revision includes all pages of the service bulletin.
COMPLIANCE INFORMATION RELATED TO THIS REVISION
No more work is necessary on airplanes changed in accordance with the original issue of this service bulletin.
Federal Aviation Administration (FAA) Airworthiness Directive FAA AD 2007-18-52 is related to this service
bulletin.
REASON FOR REVISION
This revision is sent to add clarification to this service bulletin.
Changes to this service bulletin include:
– Added borescope inspection option for the slat main track and in the slat can.
– Updated Industry Support Information with the applicable Boeing Program Letter.
– Added Damage Tolerance Information to Publications Affected.
– Added optional stainless steel lockwire to Operator Supplied Parts table and Figure 3.
– Updated Special Tooling - Price and Availability section, with Boeing's offer of two free optional toolkits to
all operators, and removed toolkit rental option.
– Added HAND reaming recommendation in the event interference occurs between the new down stop
assembly bolt and the hole in the slat main track, in the Accomplishment Instructions.
– Added the option to remove the wing anti-icing duct elbows near the down stop assembly in the right wing
near the fuel metering manifold in order to gain easier access, in the Accomplishment Instructions. If the
duct is disassembled a leak test is required.
– Added reference to Aircraft Maintenance Manual 737-600/700/800/900 AMM 57-41-02 when reinstalling
lower leading edge wing panels at the end of the Accomplishment Instructions.
– Changed lower hole tolerance limit to 0.4375 inches in the event a bushing repair becomes necessary for
the slat main track, in Figure 2.
– Added step to apply corrosion preventive compound, MIL-C-11796, Class 3, to new aft side guide bolts
upon installation, in Figure 3.
The data given in Information Notice 737-57A1302 IN 01 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.
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REVISION HISTORY
December 15, 2008Original Issue:
October 18, 2010Revision 1:
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737-57A1302Revision 1: October 18, 2010
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Commercial 
Airplanes
737
Service Bulletin
SummaryNumber: 737-57A1302Original Issue: December 15, 2008
Revision 1: October 18, 2010
ATA System: 5754
SUBJECT: WINGS - Leading Edge Slats- Main Track Down Stop Modification and Detailed
Inspection
CONCURRENT REQUIREMENTS
None.
BACKGROUND
Recently, a fuel leak and a subsequent fire resulted from loose down stop assembly hardware being pushed
through the slat can while the slats were being retracted. FAA Airworthiness Directive FAA AD 2007-18-52 was
initiated to inspect the 737NG fleet and re-torque the down stop assemblies as a result of this fire. Several issues
were found including missing hardware, low torque, and improper assembly. This service bulletin requires 1)
removal of the existing down stop assemblies and installation of a new down stop assembly on all 16 slat main
tracks, and 2) removal of the existing aft side guide attach bolts at all 64 locations and replacement with identical
bolts with drilled heads that are lock wired together on the ribs of the leading edge of the wing. Failure to
incorporate this service bulletin could lead to conditions that allow the down stop assembly to fall off, or the aft
side guides to become loose, and fall into the slat can. If the down stop assembly comes apart inside the slat
can or the aft side guide falls into the slat can, then the slat main track may trap a down stop assembly component
between the slat can and slat main track causing a puncture of the fuel tank creating a fuel leak and the risk of
fire.
As a part of a service bulletin validation program, this change was completed on airplane YC578 by Service
Bulletin 737-57A1302 Original Issue before the release of Revision 1 of this service bulletin. The change
completed on airplane YC578 by Service Bulletin 737-57A1302 Original Issue is equivalent to the release of
Revision 1 of this service bulletin. Airplane YC578 has the configuration of a Group 1 airplane.
Boeing Service Related Problem (SRP) 737-SRP-57-0209 is related to this service bulletin.
ACTION (PRR 38275-136S)
Remove the existing down stop assembly hardware from the slat main tracks of slats one through eight. Install
the new down stop assembly hardware in the correct order and torque the nut. Install the cotter pin after all other
hardware has been installed and bend the legs of the cotter pin. Remove the bolts which secure the aft side
guides to the leading edge slat track ribs and replace them with the new drilled head bolts. Install the lock wire
on the aft side guide boltheads. After the changes are done, do a detailed inspection or borescope inspection
for debris on the slat main track and in the slat can.
Special tooling is available from Boeing to assist with the installation of the down stop assembly hardware.
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EFFECTIVITY
737-600, 700, 700C, 800, 900, 900ER airplanes. See Paragraph 1.A.1., Airplanes, for effectivity.
COMPLIANCE
Refer to Paragraph 1.E., Compliance.
Federal Aviation Administration (FAA) Airworthiness Directive FAA AD 2007-18-52 is related to this service
bulletin.
INDUSTRY SUPPORT INFORMATION
Boeing Industry Support information is provided in Program Letter BPL 6-1151-737-PGM-190, dated March 9,
2009 . Additional copies of program letters are available from Boeing Warranty and Product Assurance Contracts.
MANPOWER
Refer to Paragraph 1.G., Manpower.
MATERIAL INFORMATION
Boeing Supplied Kits/Parts.
Refer to Paragraph 2.A., Material - Price and Availability
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BOEING SERVICE BULLETIN 737-57A1302
LEFT WING SHOWN
(RIGHT WING IS EQUIVALENT)
REMOVE AND REPLACE BOLT,
INSTALL LOCKWIRE AT EACH
MAIN TRACK
(4 LOCATIONS)
REMOVE AND REPLACE
DOWNSTOP.
DO A DETAILED
INSPECTION FOR DEBRIS
ON THE SLAT MAIN TRACK
AND IN THE SLAT CAN.
SLAT NUMBER 3 SHOWN  1571129
TYPICAL 16 LOCATIONS
Original Issue: December 15, 2008
Revision 1: October 18, 2010  737-57A1302
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Commercial 
Airplanes
737
Service Bulletin
Number: 737-57A1302
Original Issue: December 15, 2008
Revision 1: October 18, 2010
ATA System: 5754
SUBJECT: WINGS - Leading Edge Slats- Main Track Down Stop Modification and Detailed
Inspection
1.    PLANNING INFORMATION
A. Effectivity
1. Airplanes
Refer to Service Bulletin Index Document D6-19567 Part 3 for Airplane Variable Number, Line
Number, and Serial Number data.
This service bulletin is for the airplanes shown below. An equivalent change is on subsequent
production airplanes. Refer to PRR 38275-136S for data about this change.
DESCRIPTIONCONFIGURATIONGROUP
737-600/700/700C/800/900/900ER airplanes line numbers 1 through
2699
-1
Airplane Models:
737-600, 737-700, 737-700C, 737-800, 737-900, 737-900ER
GroupVariable Number
1YA001 - YA099
1YA101 - YA199
1YA201 - YA211
1YA221
1YA231 - YA242
1YA251 - YA256
1YA271 - YA272
1YA291
1YA301 - YA302
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GroupVariable Number
1YA311 - YA314
1YA321 - YA323
1YA336 - YA345
1YA351
1YA356 - YA357
1YA366 - YA367
1YA371 - YA377
1YA501 - YA536
1YA541 - YA552
1YA571 - YA578
1YA601 - YA615
1YA621 - YA622
1YA626 - YA631
1YA635 - YA636
1YA641 - YA642
1YA645 - YA650
1YA656 - YA659
1YA666 - YA667
1YA671 - YA672
1YA681 - YA691
1YA701 - YA710
1YA721 - YA722
1YA731 - YA734
1YA751 - YA756
1YA801 - YA803
1YA809
1YA811 - YA814
1YA831 - YA835
1YA841 - YA862
1YA881 - YA882
1YA891 - YA892
1YA961 - YA978
1YB001 - YB006
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GroupVariable Number
1YB101 - YB132
1YB151 - YB153
1YB156 - YB158
1YB161 - YB164
1YB171 - YB172
1YB181 - YB184
1YB201 - YB208
1YB271
1YB276
1YB301 - YB310
1YB371 - YB392
1YB501 - YB502
1YB521 - YB526
1YB541 - YB544
1YB551
1YB561 - YB598
1YB601 - YB632
1YB651
1YB656
1YB671 - YB672
1YB851 - YB863
1YB871 - YB874
1YB881 - YB893
1YB901 - YB903
1YB911
1YB961 - YB974
1YB986 - YB987
1YC001 - YC030
1YC051 - YC084
1YC091 - YC094
1YC101 - YC104
1YC111 - YC113
1YC121
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GroupVariable Number
1YC126 - YC127
1YC136 - YC141
1YC146 - YC147
1YC151 - YC156
1YC166 - YC171
1YC176 - YC179
1YC186 - YC190
1YC201 - YC203
1YC206 - YC207
1YC301 - YC305
1YC321 - YC387
1YC391 - YC394
1YC396
1YC401 - YC417
1YC421 - YC422
1YC426 - YC428
1YC436 - YC439
1YC441 - YC448
1YC451 - YC455
1YC459
1YC461 - YC467
1YC471 - YC499
1YC501 - YC526
1YC571 - YC583
1YC587 - YC589
1YC591 - YC593
1YC601 - YC655
1YC681 - YC696
1YC701 - YC715
1YC720 - YC725
1YC727 - YC752
1YC761 - YC770
1YC781 - YC793
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GroupVariable Number
1YC801 - YC892
1YC901 - YC907
1YC921 - YC922
1YC931 - YC932
1YC941 - YC951
1YC971 - YC978
1YC981 - YC983
1YD001 - YD007
1YD021 - YD025
1YD041 - YD057
1YD081 - YD084
1YD101 - YD110
1YD121 - YD126
1YD151 - YD159
1YD171 - YD172
1YD201 - YD203
1YD206 - YD209
1YD216 - YD219
1YD251 - YD254
1YD256 - YD257
1YD261
1YD301 - YD334
1YD391
1YD401 - YD410
1YD412 - YD415
1YD481 - YD485
1YD491 - YD499
1YD501 - YD512
1YD531 - YD535
1YD541 - YD547
1YD561 - YD564
1YD571 - YD572
1YD591 - YD595
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GroupVariable Number
1YD601 - YD612
1YD651 - YD655
1YE001 - YE020
1YE051
1YE101 - YE109
1YE151 - YE157
1YE171 - YE172
1YE201 - YE206
1YE301 - YE305
1YE321 - YE326
1YE371 - YE383
1YF001
1YF021 - YF026
1YF051 - YF052
1YF086
1YF106 - YF107
1YF111
1YF176 - YF178
1YG001 - YG044
1YG061 - YG064
1YG066 - YG089
1YG091 - YG099
1YG101 - YG103
1YG111 - YG114
1YG116 - YG120
1YG201 - YG205
1YG211 - YG214
1YG251 - YG252
1YG501 - YG509
1YG601 - YG602
1YG701
1YG711
1YH001 - YH012
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GroupVariable Number
1YH051 - YH054
1YH101 - YH114
1YH201 - YH202
1YH206 - YH207
1YH301
1YJ001 - YJ013
1YJ021
1YJ471 - YJ480
1YJ501 - YJ517
1YJ531 - YJ566
1YJ591 - YJ597
1YJ631 - YJ632
1YJ671 - YJ694
1YJ801 - YJ867
1YJ871 - YJ875
1YJ901 - YJ904
1YJ908
1YJ911 - YJ929
1YJ931 - YJ937
1YJ941 - YJ956
1YJ976 - YJ977
1YK001 - YK007
1YK101 - YK104
1YK111 - YK112
1YK121 - YK122
1YK131 - YK133
1YK136 - YK139
1YK141 - YK142
1YK146 - YK148
1YK151 - YK154
1YK161 - YK167
1YK171
1YK176
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GroupVariable Number
1YK301 - YK309
1YK321 - YK338
1YK361 - YK375
1YK401 - YK406
1YK426 - YK427
1YK431 - YK450
1YK456 - YK460
1YK476
1YK480 - YK485
1YK495
1YK511 - YK516
1YK521 - YK523
1YK551 - YK569
1YK571
1YK576 - YK577
1YK580 - YK585
1YK601 - YK602
1YK606 - YK607
1YK611 - YK616
1YK621 - YK627
1YK631 - YK634
1YK641 - YK644
1YK651 - YK661
1YK671
1YK701 - YK712
1YK716 - YK719
1YK721 - YK741
1YK751 - YK759
1YK791 - YK792
1YK796 - YK797
1YK801 - YK887
1YK901 - YK911
1YK918
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GroupVariable Number
1YK921 - YK927
1YK941 - YK952
1YK961 - YK971
1YK981 - YK985
1YL001 - YL005
1YL011 - YL016
1YL021 - YL024
1YL051 - YL052
1YL056 - YL057
1YL061
1YL066 - YL069
1YL076 - YL077
1YL101 - YL116
1YL201 - YL208
1YL271 - YL272
1YL281 - YL282
1YL301 - YL303
1YL311 - YL312
1YL316 - YL319
1YL371 - YL373
1YL421 - YL426
1YL431 - YL437
1YL461 - YL473
1YL501 - YL505
1YL531 - YL533
1YL561 - YL565
1YL591 - YL592
1YL601 - YL606
1YL611
1YL661 - YL663
1YL901 - YL906
1YL931 - YL932
1YL951 - YL952
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GroupVariable Number
1YM101 - YM103
1YM201 - YM238
1YM251 - YM299
1YM301 - YM374
1YM471
1YM481 - YM484
1YM501 - YM515
1YM521 - YM522
1YM541
1YM551 - YM553
1YM571 - YM572
1YM581 - YM582
1YM591 - YM593
1YM631 - YM634
1YM641 - YM651
1YM671 - YM672
1YM691
1YM701 - YM702
1YN001 - YN016
1YN021 - YN024
1YN061
1YN071 - YN079
1YN091 - YN092
1YN101 - YN112
1YN121
1YN201
1YN211 - YN216
1YN231 - YN232
2. Spares Affected
None.
B. Concurrent Requirements
None.
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C. Reason
Recently, a fuel leak and a subsequent fire resulted from loose down stop assembly hardware being
pushed through the slat can while the slats were being retracted. FAA Airworthiness Directive FAA AD
2007-18-52 was initiated to inspect the 737NG fleet and re-torque the down stop assemblies as a result
of this fire. Several issues were found including missing hardware, low torque, and improper assembly.
This service bulletin requires 1) removal of the existing down stop assemblies and installation of a new
down stop assembly on all 16 slat main tracks, and 2) removal of the existing aft side guide attach bolts
at all 64 locations and replacement with identical bolts with drilled heads that are lock wired together
on the ribs of the leading edge of the wing. Failure to incorporate this service bulletin could lead to
conditions that allow the down stop assembly to fall off, or the aft side guides to become loose, and
fall into the slat can. If the down stop assembly comes apart inside the slat can or the aft side guide
falls into the slat can, then the slat main track may trap a down stop assembly component between the
slat can and slat main track causing a puncture of the fuel tank creating a fuel leak and the risk of fire.
As a part of a service bulletin validation program, this change was completed on airplane YC578 by
Service Bulletin 737-57A1302 Original Issue before the release of Revision 1 of this service bulletin.
The change completed on airplane YC578 by Service Bulletin 737-57A1302 Original Issue is equivalent
to the release of Revision 1 of this service bulletin. Airplane YC578 has the configuration of a Group
1 airplane.
Revision 1: This revision is sent to add clarification to this service bulletin.
Changes to this service bulletin include:
– Added borescope inspection option for the slat main track and in the slat can.
– Updated Industry Support Information with the applicable Boeing Program Letter.
– Updated the Compliance Time in the Compliance Table.
– Updated Reference Listing.
– Added Damage Tolerance Information to Publications Affected.
– Added optional stainless steel lockwire to Operator Supplied Parts table and Figure 3.
– Updated Special Tooling - Price and Availability section, with Boeing's offer of two free optional
toolkits to all operators, and removed toolkit rental option.
– Added HAND reaming recommendation in the event interference occurs between the new down
stop assembly bolt and the hole in the slat main track, in the Accomplishment Instructions.
– Added the option to remove the wing anti-icing duct elbows near the down stop assembly in the
right wing near the fuel metering manifold in order to gain easier access, in the Accomplishment
Instructions. If the duct is disassembled a leak test is required.
– Added reference to Aircraft Maintenance Manual 737-600/700/800/900 AMM 57-41-02 when
reinstalling lower leading edge wing panels at the end of the Accomplishment Instructions.
– Changed lower hole tolerance limit to 0.4375 inches in the event a bushing repair becomes
necessary for the slat main track, in Figure 2.
– Added step to apply corrosion preventive compound, MIL-C-11796, Class 3, to new aft side guide
bolts upon installation, in Figure 3.
Boeing Service Related Problem (SRP) 737-SRP-57-0209 is related to this service bulletin.
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D. Description
Remove the existing down stop assembly hardware from the slat main tracks of slats one through eight.
Install the new down stop assembly hardware in the correct order and torque the nut. Install the cotter
pin after all other hardware has been installed and bend the legs of the cotter pin. Remove the bolts
which secure the aft side guides to the leading edge slat track ribs and replace them with the new
drilled head bolts. Install the lock wire on the aft side guide boltheads. After the changes are done, do
a detailed inspection or borescope inspection for debris on the slat main track and in the slat can.
Special tooling is available from Boeing to assist with the installation of the down stop assembly
hardware.
Revision 1 - No more work is necessary on airplanes changed in accordance with the original issue of
this service bulletin.
The work in this service bulletin is done in the maintenance zone(s) given below.
Affected Maintenance Zones
ZoneModel
522, 523, 524, 525, 622, 623, 624, 625737-600, 737-700, 737-700C,
737-800, 737-900, 737-900ER
E. Compliance
Federal Aviation Administration (FAA) Airworthiness Directive FAA AD 2007-18-52 is related to this
service bulletin.
Table 1: Slats 1 through 8 Main Track Down Stop Assembly- Modification
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
-Within 3 years after
the original issue
date of this service
bulletin
Replace down stop as-
sembly hardware with
new down stop assembly
hardware and do a de-
tailed inspection of the
slat cans and slat main
tracks for debris in accor-
dance with Paragraph
3.B., Work Instructions,
Step 2, at all 16 slat main
track locations.(a)
All Airplanes
-Within 3 years after
the original issue
date of this service
bulletin
Replace aft side guide
bolts with new aft side
guide bolts in accordance
with Paragraph 3.B.,
Work Instructions, Step
2, at all 16 slat main track
locations.(a)
All Airplanes
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Table 1: Slats 1 through 8 Main Track Down Stop Assembly- Modification
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
-Before Further
Flight
Remove debris in accor-
dance with Paragraph
3.B., Work Instructions,
Step 2.b.
Debris found in slat can
(a) Replacement of down stop assembly hardware and detailed inspection for debris on slat
main track and in slat can, in accordance with this service bulletin, terminates the repeat
inspections in FAA AD 2007-18-52.
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 the inspections and installation of the modification defined in this service
bulletin as an alternative method of compliance to the inspections and torquing required by paragraphs
(f) and (g) of AD 2007-18-52. All provisions of AD 2007-18-52 that are not specifically referenced in
this paragraph 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 inspect the work
 Time to cure the materials
 Time to make the parts
 Time to find the tools.
Elapsed HoursTask HoursNumber of Per-
sons
Task
2.7511.004Open Access
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Elapsed HoursTask HoursNumber of Per-
sons
Task
4.5018.004Figure 3 (16 loca-
tions)
3.006.002Close Access
10.2535.00TOTAL FOR EACH AIRPLANE
H. Weight and Balance Changes
Change in Moment
(Pound-Inches)
Change in Weight
(Pounds)Airplane
-270 Pound-Inches-0.4 Pounds
I. Electrical Load Data
Not applicable.
J. References
1. Existing Data
a. Engineering Change Memo PRR 38275-136S
b. Boeing Program Letter 6-1151-737-PGM-190, dated March 9, 2009
c. Boeing Service Bulletin 737-57-1293, 737-57A1301
d. Federal Aviation Administration (FAA) Airworthiness Directive 2007-18-52
e. Standard Overhaul Practices Manual (SOPM) 20-30-03, 20-44-04, 20-50-02, 20-50-03
f. 737-600/700/800/900 Aircraft Maintenance Manual (AMM) 12-22, 27-81, 27-81-21, 30-11-00,
57-41-02
g. 737-600/700/800/900 Illustrated Parts Catalog (IPC) 57-54
2. Data supplied with this Service Bulletin
None.
3. Installation Drawings Used in the Preparation of this Service Bulletin
TitleDrawing Number
SLAT RIGGING INSTL-OUTBD LE114A4001
SLAT INSTL-OUTBD LEADING EDGE, WING114A4002
SIDE GUIDE AND ROLLER INSTL-OUTBD FIXED LE116A8300
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These drawings were used to prepare this service bulletin. These drawings are not necessary to
make the specified changes, and are not supplied with this service bulletin. These drawings may
not be applicable to all airplane configurations or operators.
K. Publications Affected
1. Publications:
Chapter-SectionPublication
737-600/700/800/900 AMM 27-81,
737-600/700/800/900 AMM 12-22
737 Maintenance Manual
737-600/700/800/900 IPC 57-54737 Illustrated Parts Catalog
2. Damage Tolerance Based Structural Inspections:
Boeing has evaluated this service bulletin for effects on Fatigue Critical Structure (FCS) and for
changes to Damage Tolerance Inspections (DTI) required in the Maintenance Program. This
service bulletin does not affect FCS, therefore DTIs are not necessary.
L. Interchangeability and Intermixability of Parts
Refer to Paragraph 2.C., Parts Necessary for Each Airplane, for interchangeability and intermixability
information.
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### Page 27

2.    MATERIAL INFORMATION
A. Material - Price and Availability
Boeing can supply the kit shown in Paragraph 2.C., Parts Necessary for Each Airplane as shown below.
If there is a limit in the quantity (QTY) of kits, a supply sequence is given by Spares.
Unit Price thru
12/31/2008
QTYDateNameNumber
$5,388.00110/31/08TOP KIT, RETROFIT -
DOWNSTOP REPLACE-
MENT
002A0001-90
2001/09/09
3001/16/09
3001/23/09
5001/30/09
5003/12/09
5003/20/09
B. Industry Support Information
Boeing Industry Support information is provided in Program Letter BPL 6-1151-737-PGM-190, dated
March 9, 2009 . Additional copies of program letters are available from Boeing Warranty and Product
Assurance Contracts.
C. Parts Necessary For Each Airplane
1. Kits/Parts
To get the kits/parts shown below, refer to Paragraph 2.A., Material - Price and Availability.
Figure Kit
3Top Kit
1002A0001-90
ALL
KIT 002A0001-90
NOTES
Existing Part
NumberName
Figure
New Part Number
3
QTY
DOWN STOP FIT-
TING - SLAT MAIN
TRACK
32114A4103-5
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ALL
KIT 002A0001-90
NOTES
Existing Part
NumberName
Figure
New Part Number
3
QTY
BOLT, HEX HEAD64BACB30NM4HK13
BOLT16BACB30NR7DK12
SELF-LOCKING
NUT
16BACN10YR7CM
PIN16BACP18BC03A06P
WASHER32BACW10P22CC
2. Parts and Materials Supplied by the Operator
NotesNameQTYPart Number/ Specification
Sealant4 OzBMS 5-95, TYPE I, CLASS B
Bushing-BACB28AW06A017C
Primer1 OzBMS 10-79, TYPE III
Paint1 OzBMS 10-60, TYPE II
Corrosion Inhibiting Material4 OzBMS 3-38
Corrosion Preventive Com-
pound
4 OzMIL-C-11796, CLASS 3
Lockwire32 ftMS20995NC32  (MS20995C32
optional)
3. Parts Modified and Reidentified
None.
4. Parts Removed and Not Replaced
None.
D. Parts Necessary to Change Spares
None.
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E. Special Tooling - Price and Availability
No special tooling is necessary to do this service bulletin. However, special tooling is available to help
with the installation of the down stop assembly hardware. Boeing will supply two optional toolkits free
of charge to all operators. Refer to BPL 6-1151-737-PGM-190, dated March 9, 2009 . Send a Purchase
Order to the Director of Spares. Give this service bulletin number and the date the tools will be used.
NOTE: Customers with a fleet consisting of 737NG and Classic airplanes will receive only (2) toolkits,
one toolkit for their 737NG fleet and one for their 737 Classic fleet (refer to Boeing Service
Bulletin 737-57A1301). Additional toolkits are available for purchase.
Purchase Data:
Unit Price thru
12/31/2008
NameTool Kit Number
$2,678.00Miscellaneous Tool Main Slat
Downstop Installation Collector
MIT002A0001-90
The kits are subject to the terms and conditions of the Boeing standard purchase order
acknowledgement. After the Price date, new price data is applicable. Prices are in United States dollars.
Terms: Net 30 days.
Reference this service bulletin number and submit purchase order by one of the methods that follow:
1. Order on-line via ATA Spec 2000 or Boeing Part Page
2. Fax to (206) 662-7145
3. Spares Customer Support - MC 36-65
Boeing Spares Department
P.O. Box 3707
Seattle, Washington 98124-2207 USA
(Service Bulletin 737-57A1302)
F. Special Tooling Necessary to do this Service Bulletin
No special tooling is necessary to do this service bulletin. However, special tooling is available to help
with the installation of the down stop assembly hardware. Refer to Paragraph 2.E., Special Tooling -
Price and Availability. Maintenance and overhaul tools in the manuals shown in Paragraph 1.J.,
References, can also be necessary. Examine operator tool supply to make sure all necessary tools
are available.
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### Page 31

3.    ACCOMPLISHMENT INSTRUCTIONS
A. GENERAL INFORMATION
CAUTION: KEEP THE WORK AREA, WIRES AND ELECTRICAL BUNDLES CLEAN OF METAL
PARTICLES OR CONTAMINATION WHEN YOU USE TOOLS. UNWANTED MATERIAL,
METAL PARTICLES OR CONTAMINATION CAUGHT IN WIRE BUNDLES CAN CAUSE
DAMAGE TO THE BUNDLES. DAMAGED WIRE BUNDLES CAN CAUSE SPARKS OR
OTHER ELECTRICAL DAMAGE.
NOTE: 1. The instructions identified in Paragraph 3.B., Work Instructions and the Figure(s)
give the recommended sequence of steps. The sequence of steps to do this service
bulletin can be changed.
2. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for
definition of the acronyms.
3. Obey all of the warnings and cautions given in the specified manual sections.
4. Unless shown differently, these dimensions and tolerances are used:
– Linear dimensions are in inches
5. A Detailed Inspection is defined as: An intensive examination of a specific item,
installation, or assembly to detect damage, failure, or irregularity. Available lighting
is normally supplemented with a direct source of good lighting at an intensity deemed
appropriate. Inspection aids such as mirrors, magnifying lenses, etc. may be
necessary. Surface cleaning and elaborate procedures may be required.
6. 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.
B. WORK INSTRUCTIONS
1. PART 1 - Access
a. Do the following steps for each slat main track for slats one through eight:
(1) Remove the applicable panels from the lower leading edge surface of the wing in order
to gain access to the slat main track. Refer to 737-600/700/800/900 AMM 27-81-21 as
an accepted procedure.
(2) Align the down stop assembly with the access holes in the ribs to get access to the down
stop assembly. The slats may be positioned using the hydraulic system as given in the
following procedure.
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(a) Pressurize hydraulic system B by toggling the Hydraulic System B electric motor
pump switch, located on the P5-8 panel, to ON.
(b) Place the flap handle to detent 40.
(c) Allow the leading edge slats to fully extend.
(d) Toggle the hydraulic system B electric motor pump switch to OFF.
(e) Place the flap handle to detent 5.
(f) Turn ON, and then immediately turn OFF (Pulse), the hydraulic system B electric
motor pump switch.
(g) If the down stop assembly has not moved far enough to line up with the access holes
in the ribs, then pulse the hydraulic system B electric motor pump switch again.
Repeat this step until the down stop assembly lines up with the access holes.
NOTE: Successive start up cycles (pulses) of the hydraulic system B electric motor
pump can overheat the pump and damage it. Do not let the pump get too
hot to touch. If the pump gets hot and/or the overheat light on the P5-8
panel is illuminated, wait until the pump is cool enough to touch and the
warning light goes off before pulsing or turning on the pump.
(h) Once the down stop assembly lines up with the access holes, place the flap handle
to detent 40.
(i) After using the hydraulic system to align the down stop assembly with the access
holes, install DO-NOT-OPERATE Tags on the hydraulic switch and flap lever in the
cockpit.
WARNING: Failure to do this may result in the slats being retracted which could
cause serious bodily injury and damage to the slats.
(3) As an option to the above procedure, you can deactivate the slats, disconnect the actuator
from the slat, and move the slat manually to line up the down stop assembly with the
access holes in the ribs. Refer to 737-600/700/800/900 AMM 27-81-21 as an accepted
procedure to disconnect the actuator.
b. It is optional to remove the wing anti-icing duct elbows near the aft side of the fuel metering
manifold in the right wing in order to gain access to the down stop assembly near that location.
2. PART 2 - Preventive Modification
a. Do the following steps for each slat main track for slats one through eight:
(1) Remove the existing down stop assembly hardware (bolt, washer, down stop fitting,
sleeve, stop locator, down stop fitting, washer and nut) from the slat main track. Refer to
737-600/700/800/900 AMM 27-81-21 as an accepted procedure.
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NOTE: Be careful in handling the small parts. Do not drop them. Dropping a part into
the slat can can result in unscheduled downtime. A part left in the slat can also
create a risk of puncturing the slat can, which in turn could allow fuel to leak and
pose a risk of fire.
(2) Check the fit of the new down stop assembly bolt in the hole in the slat main track (the
new down stop bolt is identified in Figure 3):
(a) If the hole diameter is less than the bolt's shank diameter, then ream the hole up to
a max of 0.4375 inches. It is recommended that you hand ream the hole. Clean in
accordance with Boeing SOPM 20-30-03. Apply BMS 3-38, corrosion inhibiting
material, to reamed hole. If slat removal is necessary, refer to 737-600/700/800/900
AMM 27-81-21 as an accepted procedure.
(b) If the bolt has side-to-side play in the hole, then measure the hole. If the hole diameter
is less than 0.4421 no further modification is needed for the slat track. If the hole
diameter is 0.4421 to 0.5005 inches, then install a bushing in accordance with Figures
1 and 2. If slat removal is necessary, refer to 737-600/700/800/900 AMM 27-81-21
as an accepted procedure for removal and installation of the slat.
(c) If the hole diameter is greater than 0.5005 inches, then contact Boeing for further
repair instructions, or replace the slat main track.
(3) Install the new down stop assembly hardware and aft side guide bolts in accordance with
Figure 3. Optional tooling is available from Boeing to assist in installing the new down
stop assembly hardware. Refer to Paragraph 2.E., Special Tooling - Price and Availability.
NOTE: Be careful in handling the small parts. Do not drop them. Dropping a part into
the slat can can result in unscheduled downtime. A part left in the slat can also
create a risk of puncturing the slat can, which in turn could allow fuel to leak and
pose a risk of fire.
b. After all the down stop assemblies and aft side guide bolts have been modified, do a detailed
inspection or a borescope inspection for debris in the slat cans of each wing. Also look for
debris that may have fallen onto the lower rail of the slat main track. If debris is found, remove
the debris.
c. If an actuator was disconnected, then reconnect it. Refer to 737-600/700/800/900 AMM
27-81-21 as an accepted procedure. Remove the DO-NOT-OPERATE tags from the hydraulic
switch and flap lever in the cockpit if they were installed earlier.
d. If the wing anti-icing duct was disassembled, then reassemble it, and perform a leak test on
the wing anti-icing duct. Refer to 737-600/700/800/900 AMM 30-11-00 as an accepted
procedure.
3. PART III - Close Access
a. Reinstall the panels that were removed from the lower leading edge of the wing. Refer to
737-600/700/800/900 AMM 57-41-02 as an accepted procedure.
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NOTE: Before reinstalling the panels that were removed from the lower leading edge of the
wing, you may want to do the changes in Service Bulletin 737-57-1293.
b. Return the airplane to a serviceable condition.
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MORE DATAQTYIDENTIFICATIONNAMETASKSTEP
Ream the hole in
main slat track to
0.5000 - 0.5005
inches diameter.
--Slat Main TrackDrill / Ream1
Clean hole in slat
main track. Refer to
Boeing SOPM 20-
30-03 as an accept-
ed procedure.
--Slat Main TrackClean2
Apply to the hole in
the slat main track.
-BMS 5-95, TYPE I,
CLASS B
SealantApply3
Install Bushing, wet
with BMS 5-95
sealant, using the
shrink-fit method.
Refer to Boeing
SOPM 20-50-03 as
an accepted proce-
dure. Wipe off any
excess sealant.
-BACB28AW06A017CBushingInstall (New)
FIGURE 1: SHRINK-FIT BUSHING INSTALLATION
(SHEET 1 OF 1)
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MORE DATAQTYIDENTIFICATIONNAMETASKSTEP
Ream bushing inner
diameter to 0.4375 -
0.4420 inches.
-BACB28AW06A017CBushingDrill / Ream1
Clean bushing. Re-
fer to Boeing SOPM
20-30-03 as an ac-
cepted procedure.
-BACB28AW06A017CBushingClean2
Apply 1 layer of
primer to bushing
face. Refer to Boe-
ing SOPM 20-44-04
as an accepted pro-
cedure.
-BMS 10-79, TYPE IIIPrimerApply3
Apply 1 layer of
gloss enamel to
bushing face. Refer
to Boeing SOPM 20-
44-04 as an accept-
ed procedure.
-BMS 10-60, TYPE IIPaintApply4
FIGURE 2: SHRINK-FIT BUSHING REAMING
(SHEET 1 OF 1)
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### Page 37 (OCR)

BOEING SERVICE BULLETIN 737-57A1302
LEFT WING SHOWN
(RIGHT WING IS EQUIVALENT)
SLAT NUMBER 3 SHOWN  1573193
TYPICAL 16 LOCATIONS
FIGURE 3: SLAT MAIN TRACK DOWN STOP AND AFT SIDE GUIDE MODIFICATION
(SHEET 1 OF 6)
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### Page 38 (OCR)

BOEING SERVICE BULLETIN 737-57A1302
BOLT (1
SLAT
MAIN
TRACK
WASHER
DOWNSTOP
FITTING - SLAT
MAIN TRACK
PIN T  ) DOWNSTOP
FITTING - SLAT
SELF-LOCKING NUT (1)  1 WAsHER  MAIN TRACK
B
TYPICAL DOWNSTOP INSTALLATION
D
TYPICAL PIN INSTALLATION  1571121
FIGURE 3: SLAT MAIN TRACK DOWN STOP AND AFT SIDE GUIDE MODIFICATION
(SHEET 2 OF 6)
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### Page 39 (OCR)

BOEING SERVICE BULLETIN 737-57A1302
FWD
PARTS REMOVED FOR CLARITY  _ LOCKWIRE
(4 (REPRESENTATIVE)
LOCKWIRE
(REPRESENTATIVE) 4  FWD
A-A
TYPICAL SIDE GUIDE BOLT INSTALLATION
FIGURE 3: SLAT MAIN TRACK DOWN STOP AND AFT SIDE GUIDE MODIFICATION
(SHEET 3 OF 6)
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### Page 40

MORE DATAQTYIDENTIFICATIONNAMETASKSTEP
One bolt for each
slat main track, 16
per airplane. Mark
reference line on
threaded end of bolt
to show cotter pin
hole using felt-tip
pen. Install bolt with
BMS 3-38 corrosion
inhibiting material.(a)
(b)
16BACB30NR7DK12BOLTInstall (New)1
One washer under
the bolt head for
each slat main track,
16 per airplane(b)
16BACW10P22CCWASHERInstall (New)
One down stop fit-
ting on each side of
slat main track, 2 per
slat main track, 32
per airplane. Install
down stop fitting with
BMS 3-38 corrosion
inhibiting material.(b)
32114A4103-5DOWN STOP FITTING
- SLAT MAIN TRACK
Install (New)
Apply corrosion in-
hibiting material to
bolt shank and inner
faces of both down
stop fittings.
-BMS 3-38Corrosion Inhibiting
Material
Apply
One washer under
the nut for each slat
main track, 16 per
airplane(b)
16BACW10P22CCWASHERInstall (New)
Torque the nut to
180-200 inch
pounds. One nut per
slat main track, 16
per airplane(b)
16BACN10YR7CMSELF-LOCKING NUTInstall (New)
16BACP18BC03A06PPINInstall (New)
FIGURE 3: SLAT MAIN TRACK DOWN STOP AND AFT SIDE GUIDE MODIFICATION
(SHEET 4 OF 6)
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### Page 41

MORE DATAQTYIDENTIFICATIONNAMETASKSTEP
Using marked line
as reference, rotate
bolt so that cotter pin
can be installed. In-
stall cotter pin ap-
proximately as
shown in the illustra-
tion. Be careful not
to damage the bolt
threads when in-
stalling the cotter
pin. One cotter pin
for each slat main
track, 16 per air-
plane.(b)
Remove/Install one
bolt at a time per aft
side guide. If you re-
move both of the ex-
isting bolts from an
aft side guide, then
it is possible you
may have to re-
move/reinstall the
slat main track to re-
install the aft side
guide. Keep existing
washers.
32BACB30()BOLTRemove2
32 per airplane, 2 at
each slat main track
location. Install bolt
with MIL-C-11796,
Class 3, corrosion
preventive com-
pound. Re-Install
existing washers.
32BACB30NM4HK13BOLT, HEX HEADInstall (New)
Apply to new bolts
before installation.
-MIL-C-11796, CLASS
3
Corrosion Preventive
Compound
Apply
Torque bolts to 78-
82 inch pounds. 32
per airplane, 2 at
each slat main track
location.
32BACB30NM4HK13BOLT, HEX HEADTorque
FIGURE 3: SLAT MAIN TRACK DOWN STOP AND AFT SIDE GUIDE MODIFICATION
(SHEET 5 OF 6)
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: December 15, 2008
737-57A1302Revision 1 October 18, 2010
41 of 42
BOEING SERVICE BULLETIN 737-57A1302

### Page 42

MORE DATAQTYIDENTIFICATIONNAMETASKSTEP
Remove/Install one
bolt at a time per aft
side guide. If you re-
move both of the ex-
isting bolts from an
aft side guide, then
it is possible you
may have to re-
move/reinstall the
slat main track to re-
install the aft side
guide. Keep existing
washers.
32BACB30()BOLTRemove3
32 per airplane, 2 at
each slat main track
location. Install bolt
with MIL-C-11796,
Class 3, corrosion
preventive com-
pound. Re-Install
existing washers.
32BACB30NM4HK13BOLT, HEX HEADInstall (New)
Apply to new bolts
before installation.
-MIL-C-11796, CLASS
3
Corrosion Preventive
Compound
Apply
Torque bolts to 78-
82 inch pounds. 32
per airplane, 2 at
each slat main track
location.
32BACB30NM4HK13BOLT, HEX HEADTorque
Refer to Boeing
SOPM 20-50-02 as
an accepted proce-
dure.
-MS20995NC32
(MS20995C32 optional)
LockwireInstall (New)4
(a) The down stop assembly can be installed with the bolt head on either the inboard side or the outboard
side of the slat main track
(b) Optional Tool MIT002A0001-90 will ease installation of the down stop assembly and cotter pin.
FIGURE 3: SLAT MAIN TRACK DOWN STOP AND AFT SIDE GUIDE MODIFICATION
(SHEET 6 OF 6)
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: December 15, 2008
737-57A1302Revision 1 October 18, 2010
42 of 42
BOEING SERVICE BULLETIN 737-57A1302

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