# Boeing Alert Service Bulletin 737-57A1321: No revision named

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- Document: [Boeing Alert Service Bulletin 737-57A1321](https://openairdocs.org/service-documents/boeing/737-57a1321.md)
- Title as filed: SB-737-57A1321-00 -- BOEING
- Pages: 289
- PDF: https://openairdocs.org/files/sha256/3c/2b/3c2b9af4c2e6bcec26a62d059d027e01b8c53be96864bf9c98ce26190fc31fc0
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## Text

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### Page 1

Commercial 
Airplanes
737
Service Bulletin
ALERT
Number: 737-57A1321
Original Issue: February 08, 2019
ATA System: 5710 2811
SUBJECT: WINGS - Main Frame - Fuel Tank Fastener Sealant Application, Wire Bundle Clamp
Replacement and Teflon Sleeve Installation
Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15
CFR 300-774). An export license may be required before it is used for development, production or use by foreign
persons from specific countries. The controller of this data has the individual responsibility to abide by all export
laws.
9E991ECCN:
BOEING PROPRIETARY, CONFIDENTIAL AND/OR TRADE SECRET
Copyright © 2019 Boeing.
Unpublished Work. All Rights Reserved.
Treatment of this document and its content is governed by contract with Boeing. Rights to use this document
are licensed on a per aircraft basis and such rights may not be transferable. For more information, contact The
Boeing Company.
Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, Dreamliner,
BBJ, DC-8, DC-9, DC-10, KC-10, KC-46, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8, Poseidon and
Boeing liveries are all trademarks owned by The Boeing Company; and no trademark license is granted in
connection with this document unless provided in writing by Boeing.
Original Issue: February 08, 2019
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Table of Contents
S u m m a r y  ...................................................... 7
1. PLANNING INFORMATION ........................................ 1 1
A . E f f e c t i v i t y  ............................................... 1 1
1. Airplanes ............................................ 1 1
2 . S p a r e s  A f f e c t e d  ........................................ 3 8
B. Concurrent Requirements ...................................... 3 8
C. Reason ................................................ 3 8
D. Description .............................................. 3 8
E. Compliance .............................................. 3 9
F . A p p r o v a l  ............................................... 4 0
G. Manpower .............................................. 4 0
H. Weight and Balance Changes .................................... 4 3
I. Electrical Load Data ......................................... 4 3
J . R e f e r e n c e s  .............................................. 4 4
1. Existing Data: ......................................... 4 4
2. Data Supplied with this Service Bulletin: ........................... 4 4
3. Installation Drawings Used in the Preparation of this Service  Bulletin: ........... 4 4
K. Publications Affected ........................................ 4 5
L. Interchangeability and Intermixability of Parts ........................... 4 5
M. Software Accomplishment Summary ................................ 4 5
2. MATERIAL INFORMATION ........................................ 4 7
A. Material - Price and Availability ................................... 4 7
B. Industry Support Information .................................... 4 7
C. Parts Necessary for Each Airplane ................................. 4 7
1 . K i t s / P a r t s  ............................................ 4 7
2. Parts and Materials Supplied by the Operator ........................ 4 7
3. Parts Modified and Reidentified ................................ 4 8
4. Parts Removed and Not Replaced .............................. 4 8
D. Parts Necessary to Change Spares ................................. 4 8
E. Special Tooling - Price and Availability ............................... 4 8
F. Special Tooling Necessary to do this Service Bulletin ....................... 4 8
3. ACCOMPLISHMENT INSTRUCTIONS .................................. 4 9
A. GENERAL INFORMATION ..................................... 4 9
B. WORK INSTRUCTIONS ....................................... 5 1
FIGURE 1: LEFT WING REAR SPAR - FUEL TANK FASTENERS - LOCATION [ Group 2-48, 56-59] . 58
FIGURE 2: LEFT WING REAR SPAR - FUEL TANK FASTENERS - LOCATION [ G r o u p  3 7 - 4 8 ]  .... 6 1
FIGURE 3: LEFT WING REAR SPAR - FUEL TANK FASTENERS - LOCATION [ G r o u p  4 9 - 5 5 ]  .... 6 3
FIGURE 4: RIGHT WING REAR SPAR - FUEL TANK FASTENERS - LOCATION [Group 2-48, 56-59] . 65
FIGURE 5: RIGHT WING REAR SPAR - FUEL TANK FASTENERS - LOCATION [Group 37-48] . . . 68
FIGURE 6: RIGHT WING REAR SPAR - FUEL TANK FASTENERS - LOCATION [Group 49-55] . . . 70
FIGURE 7: LEFT WING FRONT SPAR - FUEL TANK FASTENERS - LOCATION [Group 2-7, 37-48, 56-59]
.................................................. 7 2
FIGURE 8: LEFT WING FRONT SPAR - FUEL TANK FASTENERS - LOCATION [ G r o u p  8 - 3 6 ]  .... 7 4
FIGURE 9: LEFT WING FRONT SPAR - FUEL TANK FASTENERS - LOCATION [Group 2-48, 56-59] . 76
FIGURE 10: LEFT WING FRONT SPAR - FUEL TANK FASTENERS - LOCATION  [Group 49-55] . . . 93
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FIGURE 11: RIGHT WING FRONT SPAR - FUEL TANK FASTENERS - LOCATIO N [Group 2-7, 37-48,
5 6 - 5 9 ]  ............................................. 1 1 2
FIGURE 12: RIGHT WING FRONT SPAR - FUEL TANK FASTENERS - LOCATIO N [Group 8-36] . . 114
FIGURE 13: RIGHT WING FRONT SPAR - FUEL TANK FASTENERS - LOCATIO N [Group 2-48, 56-59]
................................................. 1 1 6
FIGURE 14: RIGHT WING FRONT SPAR - FUEL TANK FASTENERS - LOCATIO N [Group 49-55] . 132
FIGURE 15: WING CENTER SECTION REAR SPAR - FUEL TANK FASTENERS - LOCATION [Group 2-48,
5 6 - 5 9 ]  ............................................. 1 5 0
FIGURE 16: WING CENTER SECTION REAR SPAR - FUEL TANK FASTENERS - LOCATION [Group 49-55]
................................................. 1 5 3
FIGURE 17: WING CENTER SECTION FRONT SPAR - FUEL TANK FASTENERS - LOCATION [Group
2 - 7 ,  5 6 - 5 9 ]  ........................................... 1 5 8
FIGURE 18: WING CENTER SECTION FRONT SPAR - FUEL TANK FASTENERS - LOCATION [Group
8 - 5 5 ]  .............................................. 1 6 5
FIGURE 19: LEFT WING RIB INSTALLATION - FUEL TANK FASTENERS - LO CATION [Group 2, 4-55]
................................................. 1 7 2
FIGURE 20: LEFT WING RIB INSTALLATION - FUEL TANK FASTENERS - LO CATION [Group 3, 56-59]
................................................. 1 7 9
FIGURE 21: RIGHT WING RIB INSTALLATION - FUEL TANK FASTENERS - L OCATION [Group 2, 4-55]
................................................. 1 8 5
FIGURE 22: RIGHT WING RIB INSTALLATION - FUEL TANK FASTENERS - L OCATION [Group 3, 56-59]
................................................. 1 9 2
FIGURE 23: FUEL TANK FASTENERS - SEALANT APPLICATION [Group 2-59 ]  ........... 1 9 8
FIGURE 24: LEFT WING REAR SPAR - WIRE BUNDLES - CLAMP REPLACEMENT AND TEFLON SLEEVE
INSTALLATION [Group 2-4, 6, 8, 10, 12, 16-17, 20, 24-25, 30-31, 37, 40, 42, 45, 47, 49, 51-52,
5 6 ,  5 8 ]  ............................................. 2 0 0
FIGURE 25: LEFT WING REAR SPAR - WIRE BUNDLES - CLAMP REPLACEMENT AND TEFLON SLEEVE
INSTALLATION [Group 9, 11, 18, 26, 28, 32-33, 35-36, 38, 41, 46 ,  5 0 ]  .......... 2 0 4
FIGURE 26: LEFT WING REAR SPAR - WIRE BUNDLES - CLAMP REPLACEMENT AND TEFLON SLEEVE
INSTALLATION [Group 5, 7, 13, 15, 19, 21-23, 27, 39, 43, 53, 55 ,  5 7 ,  5 9 ]  ........ 2 0 8
FIGURE 27: LEFT WING REAR SPAR - WIRE BUNDLES - CLAMP REPLACEMENT AND TEFLON SLEEVE
INSTALLATION [Group 14, 29, 34, 44, 48, 54] ....................... 2 1 2
FIGURE 28: RIGHT WING REAR SPAR - WIRE BUNDLES - CLAMP REPLACEME NT AND TEFLON
SLEEVE INSTALLATION [Group 2-8, 10, 12-13, 15-17, 19-25, 27, 30-31, 37, 39-40, 42-43, 45,
4 7 ,  4 9 ,  5 1 - 5 3 ,  5 5 - 5 9 ]  ..................................... 2 1 6
FIGURE 29: RIGHT WING REAR SPAR - WIRE BUNDLES - CLAMP REPLACEME NT AND TEFLON
SLEEVE INSTALLATION [Group 9, 11, 14, 18, 26, 28-29, 32-36, 38, 41, 44, 46, 48, 50, 54]
................................................. 2 2 0
FIGURE 30: LEFT WING FRONT SPAR - WIRE BUNDLES - CLAMP REPLACEME NT AND TEFLON
SLEEVE INSTALLATION [Group 2-7, 16, 20-21, 23-24, 30, 56-59] . . .......... 2 2 4
FIGURE 31: LEFT WING FRONT SPAR - WIRE BUNDLES - CLAMP REPLACEME NT AND TEFLON
SLEEVE INSTALLATION [Group 8-15, 17-19, 22, 25-29, 31-55] ............. 2 2 9
FIGURE 32: RIGHT WING FRONT SPAR - WIRE BUNDLES - CLAMP REPLACEM ENT AND TEFLON
SLEEVE INSTALLATION [Group 2-59] ........................... 2 3 4
FIGURE 33: FORWARD CARGO COMPARTMENT STATION 540 BULKHEAD - WIRE BUNDLES - CLAMP
REPLACEMENT AND TEFLON SLEEVE INSTALLATION [Group 2, 8-9] ......... 2 3 9
FIGURE 34: FORWARD CARGO COMPARTMENT STATION 540 BULKHEAD - WIRE BUNDLES - CLAMP
REPLACEMENT AND TEFLON SLEEVE INSTALLATION [Group 3, 10-15] . . ..... 2 4 2
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FIGURE 35: FORWARD CARGO COMPARTMENT STATION 540 BULKHEAD - WIRE BUNDLES - CLAMP
REPLACEMENT AND TEFLON SLEEVE INSTALLATION [Group 4-7, 16-32, 37-45, 49-59]
................................................. 2 4 5
FIGURE 36: FORWARD CARGO COMPARTMENT STATION 540 BULKHEAD - WIRE BUNDLES - CLAMP
REPLACEMENT AND TEFLON SLEEVE INSTALLATION [Group 33-35] ......... 2 4 8
FIGURE 37: FORWARD CARGO COMPARTMENT STATION 540 BULKHEAD - WIRE BUNDLES - CLAMP
REPLACEMENT AND TEFLON SLEEVE INSTALLATION [Group 36, 46-48] . . .... 2 5 1
FIGURE 38: MAIN WHEEL WELL STATION 663 BULKHEAD - WIRE BUNDLES - CLAMP REPLACEMENT
AND TEFLON SLEEVE INSTALLATION [Group 10-11, 16-19, 36-39, 46, 4 9 - 5 0 ]  ..... 2 5 4
FIGURE 39: MAIN WHEEL WELL STATION 663 BULKHEAD - WIRE BUNDLES - CLAMP REPLACEMENT
AND TEFLON SLEEVE INSTALLATION [Group 2, 4, 8-9, 12, 20, 40-41, 47, 51, 56] . . . 259
FIGURE 40: MAIN WHEEL WELL STATION 663 BULKHEAD - WIRE BUNDLES - CLAMP REPLACEMENT
AND TEFLON SLEEVE INSTALLATION [Group 13-14, 21-22, 42-44, 48, 5 2 - 5 4 ]  ..... 2 6 4
FIGURE 41: MAIN WHEEL WELL STATION 663 BULKHEAD - WIRE BUNDLES - CLAMP REPLACEMENT
AND TEFLON SLEEVE INSTALLATION [Group 5, 15, 23, 55, 57] ............ 2 6 9
FIGURE 42: MAIN WHEEL WELL STATION 663 BULKHEAD - WIRE BUNDLES - CLAMP REPLACEMENT
AND TEFLON SLEEVE INSTALLATION [Group 24-27, 33] ................ 2 7 4
FIGURE 43: MAIN WHEEL WELL STATION 663 BULKHEAD - WIRE BUNDLES - CLAMP REPLACEMENT
AND TEFLON SLEEVE INSTALLATION [Group 28-29, 34] ................ 2 7 9
FIGURE 44: MAIN WHEEL WELL STATION 663 BULKHEAD - WIRE BUNDLES - CLAMP REPLACEMENT
AND TEFLON SLEEVE INSTALLATION [Group 3, 6-7, 30-32, 35, 45, 58 - 5 9 ]  ...... 2 8 4
APPENDIX A: TEFLON SLEEVE INSTALLATION AT LOCATIONS WITH WIRE BUNDLE/WIRE BREAKOUT
THAT HAVE SMALL BEND RADIUS [Group 2-59] ..................... 2 8 9
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Commercial 
Airplanes
737
Service Bulletin
ALERT
SummaryNumber: 737-57A1321Original Issue: February 08, 2019
ATA System: 5710 2811
SUBJECT: WINGS - Main Frame - Fuel Tank Fastener Sealant Application, Wire Bundle Clamp
Replacement and Teflon Sleeve Installation
THIS DOCUMENT IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN
PARAGRAPH 1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS DOCUMENT
TO THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS DOCUMENT TO THE
NEW OWNER.
CONCURRENT REQUIREMENTS
None.
BACKGROUND
Accomplishment of this service bulletin will reduce the risk of ignition sources in the fuel tanks. If this service
bulletin is not done, there is a higher risk of ignition sources in the fuel tanks which can cause a fire or an
explosion.
Boeing has found that some fuel tank fasteners can be an ignition source if a fault current or hot short occurs.
A detailed analysis of the fault current threats was done to find the configuration necessary to safely conduct
the fault current threats without causing sparks in the fuel tanks. Application of sealant on the fasteners in the
fuel tanks at the wing rear spars, front spars and upper wing rib shear ties decreases the risk of ignition sources
at those fuel tank fastener locations. In addition, external to the fuel tanks at locations along the wing rear spars,
front spars, the forward cargo compartment station 540 bulkhead and the main wheel well station 663 bulkhead,
installation of cushion clamps over Teflon sleeves on wire bundles decreases metal-to-metal contact between
the clamps and their support brackets and will help prevent hot shorts.
This service bulletin gives instructions to seal fuel tank fasteners in the fuel tanks at the wing rear spars, front
spars and upper wing rib shear ties. This service bulletin also gives instructions to install cushion clamps over
Teflon sleeves on wire bundles external to the fuel tanks at locations along the wing rear spars, front spars, the
forward cargo compartment station 540 bulkhead and the main wheel well station 663 bulkhead.
This service bulletin is the result of the safety assessments conducted by Boeing under Special Federal Aviation
Regulation (SFAR) 88, Fuel Tank System Fault Tolerance Evaluation Requirements.
For Continued Airworthiness, the Structural Repair Manual (SRM) has been revised to add a new Section
51-80-01, GENERAL - LIGHTNING, ELECTRICAL WIRING AND EQUIPMENT FAULT CURRENT
REQUIREMENTS.
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### Page 8

Airworthiness Limitations (AWL's) 28-AWL-31 and 28-AWL-32, listed in the 737-300/400/500 section of
737-100/200/300/400/500 AWL's and Certification Maintenance Requirements (CMR's) document, D6-38278-CMR,
are related to this service bulletin.
Boeing Service Related Problems (SRP) 737-SRP-57-0236 and 737-SRP-57-0296 are related to this service
bulletin.
Boeing Fleet Team Digest (FTD) 737 FTD 57-10001 is related to this service bulletin.
This table is provided to operators for planning purposes only. Refer to the applicable sections for more
information.
ReferenceAffectedPlanning Data
Paragraph 1.A.2., Spares AffectedNoSpares Affected
Paragraph 1.E., Compliance and Paragraph
1.F., Approval
YesAD Related
Paragraph 1.H., Weight and Balance ChangesYesWeight and Balance Change
Paragraph 1.I., Electrical Load DataNoElectrical Load Changed
Paragraph 1.K., Publications AffectedYesPublications Affected
Paragraph 1.K., Publications AffectedNoAirplane Flight Operations Affected (Flight Crew
Operations Manual and/or FAA Approved Air-
plane Flight Manual)
Paragraph 2.C.1., Kits/PartsNoKits/Parts Required
Paragraph 2.C.2., Parts and Materials Supplied
by the Operator
YesOperator Supplied Parts/Material
Paragraph 2.F., Special Tooling Necessary to
do this Service Bulletin
NoSpecial Tooling Required
ACTION
Get access to the left main, right main and center fuel tanks. Seal fasteners on the rear spar, front spar and
upper wing rib shear ties in the left main and right main fuel tanks. Seal fasteners on the rear spar and front
spar in the center fuel tank.
External to the fuel tanks, get access to the wire bundle installation along the left and right wing rear spars and
front spars, the forward cargo compartment station 540 bulkhead and the main wheel well station 663 bulkhead.
Replace wire bundle clamps and install Teflon sleeve under the clamps.
EFFECTIVITY
All 737-300, 737-400, 737-500 Airplanes. Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplanes.
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.
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### Page 9 (OCR)

BOEING SERVICE BULLETIN 737-57A1321
ALERT  ALERT
Group 2-59:
Boeing recommends that the modification given in this service bulletin be done within 5 years after the original
issue date of this service bulletin.
Group 1:
Contact The Boeing Company for modification instructions and do the modification within 5 years after the
original issue date of this service bulletin.
INDUSTRY SUPPORT INFORMATION
Boeing warranty remedies are not available for the configuration changes given in this service bulletin.
MANPOWER
Refer to Paragraph 1.G., Manpower.
MATERIAL INFORMATION
Operator Supplied Parts/Materials. Refer to Paragraph 2.A., Material - Price and Availability.
GET ACCESS TO THE LEFT MAIN, RIGHT MAIN AND CENTER FUEL TANKS. SEAL FASTENERS ON
THE REAR SPAR, FRONT SPAR AND UPPER WING RIB SHEAR TIES IN THE LEFT MAIN AND RIGHT
MAIN FUEL TANKS. SEAL FASTENERS ON THE REAR SPAR AND FRONT SPAR IN THE CENTER
FUEL TANK.
EXTERNAL TO THE FUEL TANKS, GET ACCESS TO THE WIRE BUNDLE INSTALLATION ALONG THE
LEFT AND RIGHT WING REAR SPARS AND FRONT SPARS, THE FORWARD CARGO
COMPARTMENT STATION 540 BULKHEAD AND THE MAIN WHEEL WELL STATION 663 BULKHEAD.
REPLACE WIRE BUNDLE CLAMPS AND INSTALL TEFLON SLEEVE UNDER THE CLAMPS.
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### Page 11

Commercial 
Airplanes
737
Service Bulletin
ALERT
Number: 737-57A1321
Original Issue: February 08, 2019
ATA System: 5710 2811
SUBJECT: WINGS - Main Frame - Fuel Tank Fastener Sealant Application, Wire Bundle Clamp
Replacement and Teflon Sleeve Installation
THIS DOCUMENT IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN
PARAGRAPH 1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS DOCUMENT
TO THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS DOCUMENT TO THE
NEW OWNER.
1.    PLANNING INFORMATION
A. Effectivity
1. Airplanes
Refer to Service Bulletin Index D6-19567 Part 3 for Airplane Variable Number, Line Number, and
Serial Number data.
This service bulletin is applicable to all 737-300/400/500 Airplanes, in 59 Groups. The Variable
Numbers and Group Information for the applicable airplanes are given below. Refer to PRR
35005-304RS for data about this change.
DESCRIPTIONCONFIGURATIONGROUP
737-300/-400/-500 Airplanes with a different configuration of fuel tank
fasteners and wire bundles than the other airplane groups.
-1
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-2
737-300 Airplane with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-3
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-4
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-5
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### Page 12

DESCRIPTIONCONFIGURATIONGROUP
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-6
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-7
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-8
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-9
737-500 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-10
737-500 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-11
737-500 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-12
737-500 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-13
737-500 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-14
737-500 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-15
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-16
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-17
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-18
737-300 Airplane with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-19
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-20
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-21
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### Page 13

DESCRIPTIONCONFIGURATIONGROUP
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-22
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-23
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-24
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-25
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-26
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-27
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-28
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-29
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-30
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-31
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-32
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-33
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-34
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-35
737-500 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-36
737-400 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-37
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### Page 14

DESCRIPTIONCONFIGURATIONGROUP
737-400 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-38
737-400 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-39
737-400 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-40
737-400 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-41
737-400 Airplane with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-42
737-400 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-43
737-400 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-44
737-400 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-45
737-400 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-46
737-400 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-47
737-400 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-48
737-400 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-49
737-400 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-50
737-400 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-51
737-400 Airplane with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-52
737-400 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-53
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### Page 15

DESCRIPTIONCONFIGURATIONGROUP
737-400 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-54
737-400 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-55
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-56
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-57
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-58
737-300 Airplanes with a different configuration of fuel tank fasteners
and wire bundles than the other airplane groups.
-59
Airplane Models:
737-300, 737-400, 737-500
GroupVariable Number
37PJ301 - PJ302
40PJ551 - PJ554
1PJ555 - PJ556
40PJ557 - PJ558
1PJ559
41PJ560 - PJ561
41PJ601 - PJ615
54PJ811
49PJ816 - PJ817
1PM381
20PM382
30PM383 - PM384
20PM385
1PM386
20PM387
1PM388
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### Page 16

GroupVariable Number
20PM389 - PM392
1PM393 - PM394
20PM395 - PM396
1PM397
20PM398 - PM399
20PM401
1PM402 - PM403
20PM404 - PM405
1PM406
20PM407 - PM408
16PM409 - PM411
17PM412 - PM416
1PM417
1PM541 - PM542
17PM543 - PM549
1PM550
49PM551 - PM557
1PM558
49PM559 - PM564
1PP001 - PP002
58PP003 - PP004
1PP005
58PP006
1PP007
58PP008
1PP009
58PP010
1PP011 - PP012
6PP013 - PP014
1PP015 - PP016
6PP017 - PP020
1PP021
6PP022 - PP023
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### Page 17

GroupVariable Number
1PP024 - PP027
6PP028
1PP029 - PP033
6PP034
1PP035
6PP036
1PP037 - PP038
6PP039 - PP041
1PP042
6PP043
1PP044 - PP046
6PP047
1PP048
20PP049 - PP053
1PP054
1PP101 - PP113
6PP114
1PP115 - PP122
6PP123 - PP124
1PP125 - PP131
6PP132
1PP133 - PP135
6PP136 - PP137
1PP138 - PP150
20PP151 - PP153
17PP154 - PP160
1PP161 - PP168
6PP169
56PP181 - PP182
1PP183 - PP191
6PP192
1PP193 - PP197
20PP198 - PP199
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### Page 18

GroupVariable Number
1PP201 - PP205
3PP221
1PP231
58PP232
1PP233 - PP236
6PP237 - PP243
56PP281 - PP282
1PP283
56PP284 - PP285
4PP286
57PP301 - PP302
1PP303 - PP304
5PP305
1PP351
6PP352 - PP353
58PP376 - PP377
1PP378 - PP379
4PP380
6PP381
1PP382 - PP383
6PP384
4PP391 - PP392
1PP393
58PP401 - PP403
6PP404 - PP407
1PP408 - PP409
6PP410
1PP411 - PP412
6PP413 - PP414
1PP415 - PP416
6PP417
1PP418 - PP419
6PP420
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### Page 19

GroupVariable Number
1PP421
6PP422 - PP423
1PP424
6PP425
1PP426
6PP427 - PP430
1PP431
6PP432 - PP436
1PP437 - PP439
6PP440
1PP471
58PP472
1PP473
58PP474
1PP475
59PP501 - PP502
7PP503 - PP504
5PP505 - PP506
1PP507
23PP508 - PP512
21PP513
1PP514
21PP515
22PP516 - PP520
6PP521 - PP522
6PP631
1PP632 - PP633
6PP634
1PP651
6PP652
1PP671 - PP672
58PP673
1PP674 - PP678
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### Page 20

GroupVariable Number
58PP679
1PP680 - PP681
58PP682 - PP683
1PP684
6PP685
1PP686 - PP689
6PP690 - PP691
1PP692
6PP693 - PP694
1PP695 - PP697
6PP698
1PP699
1PP701
6PP702 - PP703
1PP704 - PP710
6PP711
1PP712 - PP720
6PP721
1PP722
6PP723
1PP724 - PP726
6PP727 - PP729
1PP730 - PP733
58PP771 - PP772
1PP773
6PP774 - PP779
7PP801 - PP802
5PP803 - PP804
23PP805 - PP808
1PP821 - PP822
6PP823
1PP824
4PP825 - PP827
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### Page 21

GroupVariable Number
1PP831
4PP832 - PP834
1PP835 - PP836
4PP837
1PP838 - PP840
4PP841
1PP842 - PP844
4PP845 - PP848
1PP851
4PP852
1PP861
2PP862
1PP863 - PP864
2PP865
1PP866 - PP867
2PP868
1PP869 - PP873
8PP874 - PP875
9PP876 - PP877
1PP891
4PP892 - PP899
4PP901
6PP902
1PP903
4PP904
1PP905 - PP908
4PP909
6PP910
1PP911 - PP912
4PP913 - PP914
1PP915 - PP916
20PP917
1PP918
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### Page 22

GroupVariable Number
20PP919
1PP920
20PP921
1PP922 - PP924
20PP925 - PP930
1PP931
6PP932
1PP933 - PP934
4PP935 - PP936
1PP946
6PP947 - PP948
4PP951 - PP952
1PP961 - PP962
4PP963 - PP965
20PP966
1PP967
1PP981 - PP982
4PP983
1PP984 - PP985
20PP986 - PP990
6PP991
1PP993
1PQ001
4PQ002 - PQ004
1PQ005
4PQ006 - PQ011
1PQ012 - PQ016
5PQ026 - PQ028
1PQ029 - PQ030
5PQ031 - PQ036
1PQ037
5PQ038 - PQ041
5PQ051 - PQ055
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### Page 23

GroupVariable Number
1PQ056
5PQ057 - PQ059
1PQ060 - PQ073
21PQ074 - PQ081
1PQ082 - PQ083
21PQ084
1PQ085
5PQ086 - PQ090
23PQ091 - PQ092
4PQ101 - PQ102
1PQ103 - PQ112
4PQ113
1PQ114
4PQ115 - PQ124
1PQ125 - PQ126
4PQ127 - PQ131
1PQ132 - PQ133
4PQ134 - PQ136
1PQ137 - PQ139
4PQ140 - PQ141
1PQ142
4PQ143 - PQ145
1PQ146 - PQ148
4PQ149 - PQ151
1PQ152 - PQ153
20PQ154 - PQ158
1PQ159
20PQ160 - PQ163
1PQ164 - PQ167
20PQ168 - PQ174
1PQ175
20PQ176 - PQ179
1PQ180
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### Page 24

GroupVariable Number
20PQ181 - PQ183
1PQ184 - PQ185
20PQ186 - PQ191
1PQ192
20PQ193 - PQ199
20PQ201 - PQ202
4PQ221 - PQ223
20PQ224 - PQ225
1PQ226 - PQ227
20PQ228
1PQ229 - PQ230
4PQ231
1PQ232
6PQ233
1PQ234 - PQ235
4PQ236
16PQ237
1PQ241
6PQ242 - PQ243
1PQ251
4PQ252 - PQ255
1PQ256
20PQ257 - PQ259
1PQ260
20PQ261
17PQ262 - PQ264
1PQ265
17PQ266
1PQ267
4PQ281
1PQ282 - PQ283
20PQ284 - PQ289
16PQ290 - PQ291
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### Page 25

GroupVariable Number
1PQ292
17PQ293
1PQ294
17PQ295 - PQ299
4PQ301
20PQ302 - PQ305
1PQ306
16PQ307
20PQ331 - PQ332
16PQ341 - PQ344
17PQ345 - PQ348
1PQ361
16PQ362 - PQ363
1PQ364
17PQ365 - PQ369
1PQ370
17PQ371 - PQ373
17PQ391 - PQ393
1PQ394
18PQ395
16PQ401
1PQ402 - PQ403
17PQ404 - PQ410
16PQ411
17PQ412
1PQ413
17PQ414
18PQ415 - PQ418
16PQ421
17PQ431 - PQ432
1PQ433
17PQ434 - PQ438
1PQ447
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### Page 26

GroupVariable Number
18PQ448
18PQ451
18PQ454
17PQ471 - PQ475
17PQ479 - PQ481
1PQ486
17PQ487
16PQ491
17PQ492 - PQ493
17PQ771 - PQ772
17PQ791 - PQ793
17PQ801 - PQ805
22PQ931 - PQ932
1PQ933
22PQ934 - PQ935
19PQ951
17PQ971 - PQ972
1PQ973
18PQ974 - PQ987
1PQ988
18PQ989 - PQ990
26PQ991 - PQ997
26PR001 - PR014
33PR015 - PR017
26PR021 - PR026
1PR027
26PR028 - PR033
33PR034
29PR041 - PR045
28PR061 - PR063
1PR064
28PR065 - PR067
1PR068
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### Page 27

GroupVariable Number
28PR069
1PR070 - PR072
34PR077 - PR080
26PR081
33PR082
26PR091 - PR092
26PR096
26PR101
33PR121 - PR122
26PR131 - PR132
26PR141 - PR142
33PR143
26PR161 - PR162
33PR163 - PR164
1PR165
33PR166 - PR172
33PR181
24PS601 - PS604
1PS605
24PS606 - PS608
25PS609 - PS612
1PS613
25PS614 - PS616
1PS617
25PS618
1PS619
25PS620 - PS629
26PS630
25PS631
24PS636 - PS638
30PS641 - PS642
24PS643
25PS644
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### Page 28

GroupVariable Number
1PS651
30PS652 - PS655
1PS656
30PS657
30PS666 - PS668
1PS669
1PS691 - PS692
1PS701 - PS704
27PS705 - PS706
25PS751
1PS752
25PS753
1PS754
25PS755 - PS757
1PS758
25PS759 - PS799
25PS811
25PS836 - PS837
25PS841 - PS844
1PS845
25PS846
25PS851 - PS852
25PS856
27PS861 - PS863
27PS866 - PS867
1PS868
26PS871 - PS874
25PS896 - PS897
31PS901 - PS928
32PS929 - PS933
1PS934
32PS935 - PS941
31PS956
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### Page 29

GroupVariable Number
1PS957
35PS961 - PS963
35PS971 - PS978
1PT001 - PT002
12PT003 - PT004
10PT005 - PT009
1PT010
10PT011 - PT014
11PT015
10PT021 - PT025
1PT026
10PT027 - PT031
12PT041 - PT045
1PT046
10PT047 - PT052
1PT053
10PT054 - PT057
1PT058
10PT059
1PT060
10PT061 - PT062
1PT063 - PT064
12PT101 - PT105
15PT121
1PT122 - PT123
15PT124 - PT125
13PT126 - PT131
14PT132 - PT138
12PT146 - PT147
1PT148
12PT161 - PT165
10PT166
1PT167
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### Page 30

GroupVariable Number
10PT168 - PT170
15PT181
1PT182
15PT183 - PT184
13PT185 - PT187
1PT188
1PT211 - PT213
10PT214
1PT215 - PT217
10PT218 - PT220
13PT295
10PT301 - PT304
1PT305
10PT306 - PT309
1PT331 - PT335
13PT336 - PT337
1PT338 - PT339
13PT340
1PT341
13PT342
1PT343
13PT344 - PT355
1PT356
13PT357
1PT358 - PT360
12PT381 - PT382
1PT383 - PT387
12PT388 - PT389
1PT390
12PT391
1PT392 - PT394
12PT395
1PT396
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### Page 31

GroupVariable Number
10PT397
1PT398 - PT399
10PT401 - PT402
1PT403 - PT406
10PT407
1PT408
10PT409
1PT410 - PT411
10PT412
1PT413 - PT419
10PT420 - PT421
1PT422 - PT423
10PT424 - PT427
1PT428
10PT429 - PT431
1PT432
10PT433 - PT438
1PT501 - PT504
10PT505 - PT512
1PT513 - PT514
10PT515 - PT517
10PT561
1PT562
10PT563 - PT565
10PT581
1PT582
10PT583 - PT585
11PT586
10PT611 - PT621
10PT641 - PT644
10PT651 - PT653
1PT654
10PT655 - PT656
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### Page 32

GroupVariable Number
10PT671 - PT672
14PT681 - PT685
10PT701 - PT703
10PT716 - PT717
10PT721
11PT722 - PT725
10PT801 - PT810
1PT811
10PT812 - PT815
1PT816
10PT817 - PT834
1PT851
10PT852 - PT853
11PT854
1PT871 - PT873
13PT874 - PT876
14PT877 - PT886
11PT901 - PT905
1PT906
11PT907 - PT930
10PT971 - PT973
11PT981 - PT984
36PT985
11PT996
1PU001 - PU008
12PU009 - PU010
1PU011 - PU016
10PU017
1PU018
10PU019 - PU024
1PU025
11PU301
36PU311 - PU313
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### Page 33

GroupVariable Number
40PV001 - PV002
45PV003
1PV004 - PV005
45PV006
1PV007 - PV008
40PV009
1PV010 - PV011
40PV012 - PV023
1PV024
40PV025
1PV026 - PV027
40PV028 - PV036
1PV037
40PV038 - PV039
1PV040
40PV041 - PV043
1PV044
40PV045
1PV046
40PV047 - PV055
37PV201 - PV205
38PV206 - PV209
49PV226 - PV227
50PV228 - PV229
1PV231
43PV232 - PV236
42PV237
37PV271
1PV272
43PV281 - PV285
44PV286 - PV287
37PV296
37PV301 - PV302
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### Page 34

GroupVariable Number
54PV351
38PV356
46PV357
40PW001 - PW002
1PW003
40PW004 - PW007
1PW008 - PW010
40PW011
1PW012
40PW013
1PW014
40PW015
51PW016
1PW017 - PW018
51PW019 - PW025
1PW026 - PW027
51PW028 - PW029
1PW030
51PW031
1PW032
51PW033
1PW034
51PW035 - PW041
1PW042
51PW043
1PW044
51PW045
49PW046 - PW050
51PW051 - PW053
49PW054
40PW061
1PW062
40PW063
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### Page 35

GroupVariable Number
1PW064
40PW065 - PW068
37PW072
37PW086 - PW088
40PW091
1PW092
51PW093
49PW094
37PW101 - PW102
49PW106
40PW111 - PW116
37PW117
40PW118
37PW119 - PW120
49PW156 - PW157
37PW161 - PW162
1PW163
37PW164
1PW165
37PW166 - PW167
38PW168 - PW171
37PW201 - PW202
1PW203
37PW204 - PW207
1PW208 - PW209
37PW210 - PW217
1PW218 - PW220
37PW221 - PW251
38PW252
49PW261 - PW262
50PW263 - PW264
49PW265 - PW268
49PW271 - PW272
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### Page 36

GroupVariable Number
1PW273
49PW274
1PW275
49PW276
1PW278
49PW281 - PW291
1PW292
49PW293
49PW296
39PW301
1PW302
39PW303 - PW319
1PW320 - PW321
39PW322 - PW327
37PW401 - PW403
38PW404 - PW405
46PW406 - PW408
37PW411 - PW413
38PW414 - PW418
38PW421 - PW424
38PW431 - PW432
46PW433 - PW435
44PW441 - PW446
48PW447 - PW450
43PW461 - PW464
1PW465
43PW466 - PW467
55PW501 - PW504
55PW511 - PW516
53PW517
55PW518
53PW519 - PW522
53PW524 - PW530
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### Page 37

GroupVariable Number
51PW531 - PW533
1PW534
51PW535 - PW537
49PW538 - PW550
1PW556
49PW557
55PW561 - PW564
1PW571
55PW572 - PW574
53PW575 - PW576
51PW591
1PW592
51PW593 - PW595
49PW596
51PW611 - PW612
1PW613 - PW615
51PW616
47PW617 - PW619
1PW620
47PW621 - PW622
51PW631 - PW632
49PW633 - PW636
1PW637
51PW661 - PW662
49PW681 - PW683
49PW701 - PW702
53PW711 - PW717
52PW741
49PW742
49PW761
49PW771
50PW831
50PW851 - PW856
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### Page 38

2. Spares Affected
None.
B. Concurrent Requirements
None.
C. Reason
Accomplishment of this service bulletin will reduce the risk of ignition sources in the fuel tanks. If this
service bulletin is not done, there is a higher risk of ignition sources in the fuel tanks which can cause
a fire or an explosion.
Boeing has found that some fuel tank fasteners can be an ignition source if a fault current or hot short
occurs. A detailed analysis of the fault current threats was done to find the configuration necessary to
safely conduct the fault current threats without causing sparks in the fuel tanks. Application of sealant
on the fasteners in the fuel tanks at the wing rear spars, front spars and upper wing rib shear ties
decreases the risk of ignition sources at those fuel tank fastener locations. In addition, external to the
fuel tanks at locations along the wing rear spars, front spars, the forward cargo compartment station
540 bulkhead and the main wheel well station 663 bulkhead, installation of cushion clamps over Teflon
sleeves on wire bundles decreases metal-to-metal contact between the clamps and their support
brackets and will help prevent hot shorts.
This service bulletin gives instructions to seal fuel tank fasteners in the fuel tanks at the wing rear spars,
front spars and upper wing rib shear ties. This service bulletin also gives instructions to install cushion
clamps over Teflon sleeves on wire bundles external to the fuel tanks at locations along the wing rear
spars, front spars, the forward cargo compartment station 540 bulkhead and the main wheel well station
663 bulkhead.
This service bulletin is the result of the safety assessments conducted by Boeing under Special Federal
Aviation Regulation (SFAR) 88, Fuel Tank System Fault Tolerance Evaluation Requirements.
For Continued Airworthiness, the Structural Repair Manual (SRM) has been revised to add a new
Section 51-80-01, GENERAL - LIGHTNING, ELECTRICAL WIRING AND EQUIPMENT FAULT
CURRENT REQUIREMENTS.
Airworthiness Limitations (AWL's) 28-AWL-31 and 28-AWL-32, listed in the 737-300/400/500 section
of 737-100/200/300/400/500 AWL's and Certification Maintenance Requirements (CMR's) document,
D6-38278-CMR, are related to this service bulletin.
Boeing Service Related Problems (SRP) 737-SRP-57-0236 and 737-SRP-57-0296 are related to this
service bulletin.
Boeing Fleet Team Digest (FTD) 737 FTD 57-10001 is related to this service bulletin.
D. Description
Get access to the left main, right main and center fuel tanks. Seal fasteners on the rear spar, front spar
and upper wing rib shear ties in the left main and right main fuel tanks. Seal fasteners on the rear spar
and front spar in the center fuel tank.
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External to the fuel tanks, get access to the wire bundle installation along the left and right wing rear
spars and front spars, the forward cargo compartment station 540 bulkhead and the main wheel well
station 663 bulkhead. Replace wire bundle clamps and install Teflon sleeve under the clamps.
The work in this service bulletin is done in the maintenance zone(s) given below.
Group 1:
Affected Maintenance Zones
ZoneModel
221, 305, 405737-300, 737-400, 737-500
Group 2-9, 16-35, 56-59:
Affected Maintenance Zones
ZoneModel
221, 305, 405737-300
Group 10-15, 36:
Affected Maintenance Zones
ZoneModel
221, 305, 405737-500
Group 37-55:
Affected Maintenance Zones
ZoneModel
221, 305, 405737-400
E. Compliance
The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to
this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this
service bulletin mandatory.
Group 2-59:
Boeing recommends that the modification given in this service bulletin be done within 5 years after the
original issue date of this service bulletin.
Group 1:
Contact The Boeing Company for modification instructions and do the modification within 5 years after
the original issue date of this service bulletin.
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F. Approval
This service bulletin was examined by the Federal Aviation Administration (FAA). The changes specified
in this service bulletin comply with the applicable regulations and are FAA approved, as well as European
Aviation Safety Agency (EASA)/Joint Aviation Authorities (JAA) approved for all EASA/JAA approved
airplanes listed in the service bulletin effectivity. This service bulletin and its approval were based on
the airplane in its original Boeing delivery configuration or as modified by other approved Boeing
changes.
If an airplane has a non-Boeing modification or repair that affects a component or system also affected
by this service bulletin, the operator is responsible for obtaining appropriate regulatory agency approval
before incorporating this service bulletin.
G. Manpower
The table below shows an estimate of the task hours necessary to do this 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.
Group 1:
Contact Boeing.
Group 2-59:
WORK PACKAGE 1 : FUEL TANKS - FASTENER SEALING
Elapsed HoursTask HoursNumber of PersonsTask
7.2529.004Open Access
3.406.802FIGURE 1
0.500.501FIGURE 2
2.252.251FIGURE 3
4.509.002FIGURE 4
0.500.501FIGURE 5
2.254.502FIGURE 6
2.002.001FIGURE 7
2.002.001FIGURE 8
9.2036.804FIGURE 9
9.7539.004FIGURE 10
2.002.001FIGURE 11
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Group 2-59:
WORK PACKAGE 1 : FUEL TANKS - FASTENER SEALING
Elapsed HoursTask HoursNumber of PersonsTask
2.002.001FIGURE 12
9.7539.004FIGURE 13
10.7543.004FIGURE 14
2.502.501FIGURE 15
3.503.501FIGURE 16
25.25101.004FIGURE 17
25.25101.004FIGURE 18
4.804.801FIGURE 19
3.903.901FIGURE 20
4.804.801FIGURE 21
3.903.901FIGURE 22
14.5529.102FIGURE 23
5.0020.004Close Access
(a)(a)TOTAL FOR EACH AIRPLANE
(a) Refer to Paragraph 3.B., Work Instructions to find the applicability of each
figure. The total hours for an airplane can then be calculated.
Group 2-59:
WORK PACKAGE 2: EXTERNAL TO THE FUEL TANKS AT THE LEFT AND RIGHT WING
REAR SPAR - WIRE BUNDLE CLAMP REPLACEMENT AND TEFLON SLEEVE INSTALLATION
Elapsed HoursTask HoursNumber of PersonsTask
1.001.001Open Access
5.5011.002FIGURE 24
5.5011.002FIGURE 25
5.5011.002FIGURE 26
5.5011.002FIGURE 27
5.5011.002FIGURE 28
5.5011.002FIGURE 29
1.001.001Close Access
(a)(a)TOTAL FOR EACH AIRPLANE
(a) Refer to Paragraph 3.B., Work Instructions to find the applicability of each
figure. The total hours for an airplane can then be calculated.
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Group 2-59:
WORK PACKAGE 3: EXTERNAL TO THE FUEL TANKS AT THE LEFT AND RIGHT WING
FRONT SPAR - WIRE BUNDLE CLAMP REPLACEMENT AND TEFLON SLEEVE INSTALLA-
TION
Elapsed HoursTask HoursNumber of PersonsTask
0.500.501Open Access
4.4517.804FIGURE 30
4.4517.804FIGURE 31
4.4517.804FIGURE 32
0.500.501Close Access
(a)(a)TOTAL FOR EACH AIRPLANE
(a) Refer to Paragraph 3.B., Work Instructions to find the applicability of each
figure. The total hours for an airplane can then be calculated.
Group 2-59:
WORK PACKAGE 4 - EXTERNAL TO THE FUEL TANKS AT THE FORWARD CARGO COM-
PARTMENT STATION 540 BULKHEAD - WIRE BUNDLE CLAMP REPLACEMENT AND
TEFLON SLEEVE INSTALLATION
Elapsed HoursTask HoursNumber of PersonsTask
0.650.651Open Access
2.752.751FIGURE 33
2.752.751FIGURE 34
2.752.751FIGURE 35
2.752.751FIGURE 36
2.752.751FIGURE 37
0.650.651Close Access
(a)(a)TOTAL FOR EACH AIRPLANE
(a) Refer to Paragraph 3.B., Work Instructions to find the applicability of each
figure. The total hours for an airplane can then be calculated.
Group 2-59:
WORK PACKAGE 5 - EXTERNAL TO THE FUEL TANKS AT THE MAIN WHEEL WELL STA-
TION 663 BULKHEAD - WIRE BUNDLE CLAMP REPLACEMENT AND TEFLON SLEEVE IN-
STALLATION
Elapsed HoursTask HoursNumber of PersonsTask
0.600.601Open Access
3.3013.204FIGURE 38
3.3013.204FIGURE 39
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Group 2-59:
WORK PACKAGE 5 - EXTERNAL TO THE FUEL TANKS AT THE MAIN WHEEL WELL STA-
TION 663 BULKHEAD - WIRE BUNDLE CLAMP REPLACEMENT AND TEFLON SLEEVE IN-
STALLATION
Elapsed HoursTask HoursNumber of PersonsTask
3.3013.204FIGURE 40
3.3013.204FIGURE 41
3.3013.204FIGURE 42
3.3013.204FIGURE 43
3.3013.204FIGURE 44
1.151.151Close Access
(a)(a)TOTAL FOR EACH AIRPLANE
(a) Refer to Paragraph 3.B., Work Instructions to find the applicability of each
figure. The total hours for an airplane can then be calculated.
H. Weight and Balance Changes
The below weight and balance changes are after all work packages in Paragraph 3.B., Work Instructions
have been done.
Change in Moment
(Pound-Inches)
Change in Weight
(Pounds)Airplane
(a)(a)Group 1
6822.311.3Group 2
5531.09.2Group 3-7, 20-21, 23-24, 30, 56-59
7468.012.4Group 8-9
5337.38.9Group 10-11, 17-19, 36-39, 46, 49-50
5251.28.7Group 12, 54
6176.710.3Group 13, 15, 22, 25-27, 31-33, 35, 40-43, 45, 47, 51-53
6198.210.3Group 14, 29, 34, 44, 48
4691.77.8Group 16
5939.99.9Group 28
7123.611.8Group 55
(a) Contact Boeing.
I. Electrical Load Data
Not changed.
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J. References
1. Existing Data:
a. Boeing Service Related Problem (SRP) 737-SRP-57-0236, 737-SRP -57-0296
b. Service Bulletin Index D6-19567
c. Standard Overhaul Practices Manual (SOPM) 20-30-93, 20-50-01
d. Standard Wiring Practices Manual (SWPM) 20-00-11, 20-10-11, 2 0-10-12, 20-10-19
e. 737 Fleet Team Digest (FTD) 57-10001
f. 737-300/400/500 Aircraft Maintenance Manual (AMM) 12-31-61, 25-52-81, 27-61-00, 27-81-00,
28-10-00, 28-11-00, 28-11-11, 28-11-31, 28-23-00, 32-00-01, 52-31-00
2. Data Supplied with this Service Bulletin:
None.
3. Installation Drawings Used in the Preparation of this Service  Bulletin:
TitleDrawing Number
FRONT SPAR INSTALLATION - WING65-45320
REAR SPAR INSTALLATION - WING65-45321
FRONT SPAR INSTALLATION - WING CENTER SECTION65-45401
REAR SPAR INSTALLATION - WING CENTER SECTION65-45402
RIB INSTL-WBL 135.565-45445
RIB INSTL-WBL 157.0065-45446
RIB INSTALLATION-INSPAR, WBL 183.4065-45447
RIB INSTL-INSPAR, WBL 198.6065-45449
WIRE BUNDLE INSTALLATION - L. H. LEADING EDGE & FRONT
SPAR SECTION 20 WBL 71.24 TO FSS 626.93
65-48301
WIRE BUNDLE INSTALLATION - R. H. LEADING EDGE & FRONT
SPAR SECTION 20 WBL 71.24 TO FSS 626.93
65-48302
WIRE BUNDLE INSTALLATION - L. H. REAR SPAR RSS 259.38
TO RSS 652.9 SECTION 20
65-48307
WIRE BUNDLE INSTALLATION - R. H. REAR SPAR RSS 259.38
TO RSS 637.96 SECTION 20
65-48308
WIRE BUNDLE INSTALLATION - L. H. FILLET AREA & REAR
SPAR SECTION 20 WBL 71.24 TO RSS 259.38
65-48309
WIRE BUNDLE INSTALLATION - R. H. FILLET AREA & REAR
SPAR SECTION 20 WBL 71.24 TO RSS 259.38
65-48310
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TitleDrawing Number
WIRE BUNDLE INSTALLATION - FORWARD CARGO COMPART-
MENT STATION 380 - 540 & FLOOR BEAMS STATION 380 - 727
65-48331
WIRE BUNDLE INSTALLATION - MAIN WHEEL WELL STATION
663.75 - 727
65-48339
The table above lists applicable drawings used to prepare this service bulletin. The drawings are
not necessary to make the specified changes, and are not supplied with this service bulletin. The
drawings may not be applicable to all airplane configurations or operators.
K. Publications Affected
1. Publications:
Chapter-SectionPublication
Section C.1 Fuel Systems Ignition Prevention, 737-
300/400/500 Maintenance Planning Data 28-AWL-31
and 28-AWL-32
D6-38278-CMR, 737-12345 Airworthiness Limita-
tions/Certification Maintenance Requirements
2. Damage Tolerance Based Structural Inspections:
Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue
Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the
Maintenance Program. This service bulletin affects FCS but no new DTIs are necessary.
L. Interchangeability and Intermixability of Parts
Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts.
M. Software Accomplishment Summary
Not affected.
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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 configuration changes given in this service bulletin.
C. Parts Necessary for Each Airplane
1. Kits/Parts
None.
2. Parts and Materials Supplied by the Operator
The following parts or materials are necessary to do the change in this service bulletin. Parts and
materials in the manuals given in Paragraph 1.J., References, can also be necessary. Examine
operator part and material supply to make sure all necessary parts and materials are available.
NotesNameQTYPart Number / Specification
(a)CUSHION CLAMP294BACC10JU(103 thru 109); or BACC10GU(101 thru 109)
(b)TEFLON SLEEVE120 FEETTFE-2X, STANDARD WALL
(c)TEFLON TAPE20 FEETPTFE, GRADE D, CLASS 2
(d)LACING TAPE1200 FEETBMS13-54, TYPE III, CLASS 1, FINISH C, WHITE; or
BMS13-54, TYPE III, CLASS 1, FINISH C, BLACK
SEALANT10
OUNCES
BMS 5-45, CLASS A-2, GRADE 1; or BMS 5-45, CLASS
A-2, GRADE 2
SEALANT10
OUNCES
BMS 5-45, CLASS B-2
WIPER5BMS 15-5, CLASS A, PROCESS CLEANING AB-
SORBENT WIPER
(a) The quantity and size of the clamp required can vary and depends on clamp location, wire bundle
installation and airplane configuration. Refer to wire bundle FIGURES 24 thru 44, as applicable, for
more information. Cushion clamps are available from Boeing.
(b) Use Teflon sleeve material that is twice the diameter of the wire bundle and will provide a minimum
of a 50% circumferential overlap when cut and wound around the wire bundle. Refer to wire bundle
FIGURES 24 thru 44, as applicable, for more information. Refer to SWPM 20-10-11 for supplier in-
formation.
(c) Refer to SWPM 20-00-11 for materials and supplier information. Teflon tape is used in APPENDIX
A.
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NotesNameQTYPart Number / Specification
(d) See the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier
data.
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.
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3.    ACCOMPLISHMENT INSTRUCTIONS
A. GENERAL INFORMATION
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.
CAUTION
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. The work instructions are divided into work packages. Each wo rk package can be
completed independently during separate maintenance visits. Task Hours and Elapsed
Hours for each package are given in Paragraph 1.G., Manpower.
4. Unless shown differently, these dimensions and tolerances are  used:
– Linear dimensions are in inches
– Tolerance on linear dimensions, other than rivet and bolt edge  margins, is plus
or minus 0.03 inch
– Tolerance on rivet and bolt edge margin is plus or minus 0.05 inch
– Angular tolerance is plus or minus 2 degrees
– Hole dimensions for standard solid rivets and fasteners are in  Structural Repair
Manual (SRM) Chapter 51
– Torque Values:
— Values for structural fasteners are given in 737 Structural Repair Manual,
Chapter 51.
— Values for airframe maintenance tasks are included in Chapter 20 of 737
Aircraft Maintenance Manual (AMM).
— Values for electrical maintenance tasks are included in Chapter 20 of
Standard Wiring Practices Manual (SWPM).
— Non-standard torque values for maintenance tasks are included in the
applicable installation step.
5. Use the approved fastener, process and material substitutions  in accordance with
SRM Chapter 51.
6. Refer to the SWPM 20-10-11 and SWPM 20-10-12 for the wire ins tallation procedures,
and SWPM 20-10-19 for the wire separation requirements, as accepted procedures.
7. The necessary conditions for selection of clamp type and size  are included in SWPM
20-10-12. If any wire bundle support clamp specified in this service bulletin does not
make a correct fit on the wire bundle, refer to SWPM 20-10-12 as an accepted
procedure to select a clamp that fits correctly.
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8. If the length of any fastener specified in this service bulle tin does not meet installation
standards given in SRM Chapter 51, then a fastener of the same specification, or
an approved substitute, with a length which meets the installation standards given
in SRM Chapter 51 may be used. In addition, washers may be installed for fastener
grip length in accordance with SRM Chapter 51. Refer to SOPM 20-50-01 for alternate
full threaded fasteners (screws) needed for installation in this service bulletin.
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. The instructions in Paragraph 3.B., Work Instructions and th e figures can include
operation of tools or test equipment. Boeing Engineering Tool Drawings, the Illustrated
Tool and Equipment Manual, and the Special Tool and Ground Handling Drawing
Index contain data on versions of the tools or test equipment that you can use. It is
permitted to use replaced tools. It is not permitted to use superseded tools.
11. If it is necessary to remove more parts for access, you can remove those parts. If
you can get access without removing identified parts, it is not necessary to remove
all of the identified parts. Jacking and shoring limitations must be observed.
12. Where the work instructions include installation of a kept p art, a new or serviceable
part with the same part number can be installed as an alternative to the kept part.
13. This service bulletin includes functional test procedures fo r the systems changed by
this service bulletin. More functional tests can possibly be necessary in accordance
with standard maintenance practices because of interruption to other airplane systems.
14. Use of colors in Figures is based on guidance from the ATA e -Business Program
(ATA) iSpec 2200.
15. The compliance times for the actions in Paragraph 3.B., WORK  INSTRUCTIONS
are in Paragraph 1.E., Compliance.
16. Some steps in the Work Instructions are labeled as Required for Compliance (RC).
If this service bulletin is mandated by an Airworthiness Directive (AD), then the steps
labeled as RC, including sub-steps under an RC step and any figures identified in
an RC step, must be done to comply with the AD. If a step or sub-step is labeled
"RC Exempt," then the RC requirement is removed from that step or sub-step. An
Alternative Method of Compliance (AMOC) is required for any deviations to RC steps,
including sub-steps and identified figures. Steps not labeled as RC may be deviated
from using accepted methods in accordance with the operator's maintenance or
inspection program without obtaining approval of an AMOC. This is provided that
the RC steps, including sub-steps and identified figures, can still be done as specified,
and the airplane can be put back in an airworthy condition.
17. Approved wire bundle clamp installation deviations:
• At locations where tandem clamps are shown in figures, single clamps can exist
for your airplane configuration and this is acceptable.
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• The existing clamp quantity and location can be different to t hat shown in the
figures. If the existing clamp quantity or location is different, make sure that the
work at each clamp agrees with the requirements for installing a clamp with a
TFE-2X, STANDARD WALL Teflon sleeve under the clamp in accordance with
this service bulletin.
• Orientation of existing clamps shown in figures are for refere nce only, and can
be different from your airplane configuration.
• Wire bundles and routing shown in this service bulletin can be  different to that
on the airplane. Existing wire bundle configuration is acceptable if installed
(clamp size, routing and bend radii) to the standards of SWPM 20-10-11 and
SWPM 20-10-12, and the clamps and TFE-2X, STANDARD WALL Teflon sleeves
are installed in accordance with the requirements of this service bulletin. If
existing wire bundle configuration are not installed to the standards of SWPM
20-10-11 or SWPM 20-10-12, then contact Boeing for further review and
disposition.
• Wire bundles that are protected by existing BMS13-52 expando s leeves must
be covered with TFE-2X, STANDARD WALL Teflon Sleeve.
• Wire bundle segments with sharp bends (small radius) near a cl amp or other
interference, can deviate from centering of the TFE-2X, STANDARD WALL
Teflon sleeve to the clamp. It is acceptable to center the minimum 3 inch TFE-2X,
STANDARD WALL Teflon sleeve as close as possible to the clamp.
18. Refer to SWPM 20-10-12 for the definition of cushion clamp r ubber cushion damage,
as an accepted procedure.
B. WORK INSTRUCTIONS
Group 1:
Contact The Boeing Company for modification instructions and do the modification.
Group 2-59:
WORK PACKAGE 1: FUEL TANKS - FASTENER SEALING
1. Defuel the left main, right main and center fuel tanks. Refer  to 737-300/400/500 AMM 28-23-00
as an accepted procedure.
2. Purge the left main, right main and center fuel tanks. Refer to 737-300/400/500 AMM 28-10-00 as
an accepted procedure.
3. Remove and keep the left main and right main fuel tank access  doors. Refer to 737-300/400/500
AMM 28-11-11 as an accepted procedure.
Main Fuel Tank Access Doors
Access Door Number
(Right Tank)
Access Door Number
(Left Tank)
Name
75017101Surge Tank Access Door
74027202Fuel Tank Access Door No. 1
74047204Fuel Tank Access Door No. 2
74057205Fuel Tank Access Door No. 3
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Main Fuel Tank Access Doors
Access Door Number
(Right Tank)
Access Door Number
(Left Tank)
Name
74067206Fuel Tank Access Door No. 4
74077207Fuel Tank Access Door No. 5
74087208Fuel Tank Access Door No. 6
74097209Fuel Tank Access Door No. 7
74107210Fuel Tank Access Door No. 8
74117211Fuel Tank Access Door No. 9
74127212Fuel Tank Access Door No. 10
74137213Fuel Tank Access Door No. 11
74147214Fuel Tank Access Door No. 12
4. Remove and keep the center fuel tank access doors. Refer to 7 37-300/400/500 AMM 28-11-31
as an accepted procedure.
Center Fuel Tank Access Doors
Access Door Number
(Right)
Access Door Number
(Left)
Name
33043303Fuel Tank Access Door
5. RC - Locate and seal fuel tank fasteners as follows:
a. Left Wing Rear Spar
(1) Group 2-36, 56-59:
Locate and seal the fasteners common to the left wing rear spar in accordance with
FIGURE 1 and FIGURE 23.
(2) Group 37-48:
Locate and seal the fasteners common to the left wing rear spar in accordance with
FIGURE 1, FIGURE 2, and FIGURE 23.
(3) Group 49-55:
Locate and seal the fasteners common to the left wing rear spar in accordance with
FIGURE 3 and FIGURE 23.
b. Right Wing Rear Spar
(1) Group 2-36, 56-59:
Locate and seal the fasteners common to the right wing rear spar in accordance with
FIGURE 4 and FIGURE 23.
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### Page 53

(2) Group 37-48:
Locate and seal the fasteners common to the right wing rear spar in accordance with
FIGURE 4, FIGURE 5 and FIGURE 23.
(3) Group 49-55:
Locate and seal the fasteners common to the right wing rear spar in accordance with
FIGURE 6 and FIGURE 23.
c. Left Wing Front Spar
(1) Group 2-7, 37-48, 56-59:
Locate and seal the fasteners common to the left wing front spar in accordance with
FIGURE 7, FIGURE 9 and FIGURE 23.
(2) Group 8-36:
Locate and seal the fasteners common to the left wing front spar in accordance with
FIGURE 8, FIGURE 9 and FIGURE 23.
(3) Group 49-55:
Locate and seal the fasteners common to the left wing front spar in accordance with
FIGURE 10 and FIGURE 23.
d. Right Wing Front Spar
(1) Group 2-7, 37-48, 56-59:
Locate and seal the fasteners common to the right wing front spar in accordance with
FIGURE 11, FIGURE 13 and FIGURE 23.
(2) Group 8-36:
Locate and seal the fasteners common to the right wing front spar in accordance with
FIGURE 12, FIGURE 13 and FIGURE 23.
(3) Group 49-55:
Locate and seal the fasteners common to the right wing front spar in accordance with
FIGURE 14 and FIGURE 23.
e. Wing Center Section Rear Spar
(1) Group 2-48, 56-59:
Locate and seal the fasteners common to the wing center section rear spar in accordance
with FIGURE 15 and FIGURE 23.
(2) Group 49-55:
Locate and seal the fasteners common to the wing center section rear spar in accordance
with FIGURE 16 and FIGURE 23.
f. Wing Center Section Front Spar
(1) Group 2-7, 56-59:
Locate and seal the fasteners common to the wing center section front spar in accordance
with FIGURE 17 and FIGURE 23.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: February 08, 2019
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ALERTALERT

### Page 54

(2) Group 8-55:
Locate and seal the fasteners common to the wing center section front spar in accordance
with FIGURE 18 and FIGURE 23.
g. Left Upper Wing Rib Shear Ties
(1) Group 2, 4-55:
Locate and seal the fasteners common to the left upper wing rib shear ties in accordance
with FIGURE 19 and FIGURE 23.
(2) Group 3, 56-59:
Locate and seal the fasteners common to the left upper wing rib shear ties in accordance
with FIGURE 20 and FIGURE 23.
h. Right Upper Wing Rib Shear Ties
(1) Group 2, 4-55:
Locate and seal the fasteners common to the right upper wing rib shear ties in accordance
with FIGURE 21 and FIGURE 23.
(2) Group 3, 56-59:
Locate and seal the fasteners common to the right upper wing rib shear ties in accordance
with FIGURE 22 and FIGURE 23.
MAKE SURE YOU REMOVE ALL UNWANTED PARTICLES AND MATERIALS
FROM THE FUEL TANKS. UNWANTED MATERIALS CAN COLLECT IN THE
FUEL TANKS, WHICH CAN CAUSE BLOCKAGE OR INCORRECT SYSTEM
OPERATION.CAUTION
6. Install kept center fuel tank access doors. Refer to 737-300/400/500 AMM 28-11-31 as an accepted
procedure.
7. Install kept left main and right main fuel tank access doors. Refer to 737-300/400/500 AMM 28-11-11
as an accepted procedure.
8. Make sure that all removed and then installed fuel tank acces s doors do not leak fuel. Refer to
737-300/400/500 AMM 28-11-00 as an accepted procedure.
9. Put the airplane back to a serviceable condition.
Group 2-59:
WORK PACKAGE 2: EXTERNAL TO THE FUEL TANKS AT THE LEFT AND RIGHT WING REAR
SPAR - WIRE BUNDLE CLAMP REPLACEMENT AND TEFLON SLEEVE INSTALLATION
1. Get access to the left and right wing rear spar. Extend the i nboard and outboard spoilers. Refer
to 737-300/400/500 AMM 27-61-00 as an accepted procedure.
2. Remove and keep the left wing access panel 8408. Refer to 737 -300/400/500 AMM 12-31-61 as
an accepted procedure.
3. Remove and keep the right wing access panel 8508. Refer to 73 7-300/400/500 AMM 12-31-61
as an accepted procedure.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
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ALERTALERT

### Page 55

4. RC - Replace wire bundle clamps and install TFE-2X Teflon sleeve under the clamps on the wire
bundle installation along the left wing rear spar:
a. Group 2-4, 6, 8, 10, 12, 16-17, 20, 24-25, 30-31, 37, 40, 42, 45, 47, 49, 51-52, 56, 58:
In accordance with FIGURE 24.
b. Group 9, 11, 18, 26, 28, 32-33, 35-36, 38, 41, 46, 50:
In accordance with FIGURE 25.
c. Group 5, 7, 13, 15, 19, 21-23, 27, 39, 43, 53, 55, 57, 59:
In accordance with FIGURE 26.
d. Group 14, 29, 34, 44, 48, 54:
In accordance with FIGURE 27.
5. RC - Replace wire bundle clamps and install TFE-2X Teflon sleeve under the clamps on the wire
bundle installation along the right wing rear spar:
a. Group 2-8, 10, 12-13, 15-17, 19-25, 27, 30-31, 37, 39-40, 42-43, 45, 47, 49, 51-53, 55-59:
In accordance with FIGURE 28.
b. Group 9, 11, 14, 18, 26, 28-29, 32-36, 38, 41, 44, 46, 48, 50, 54:
In accordance with FIGURE 29.
6. Install kept left wing access panel 8408. Refer to 737-300/400/500 AMM 12-31-61 as an accepted
procedure.
7. Install kept right wing access panel 8508. Refer to 737-300/400/500 AMM 12-31-61 as an accepted
procedure.
MAKE SURE ALL PERSONS AND EQUIPMENT ARE CLEAR OF THE FLIGHT
CONTROL SURFACES, THE THRUST REVERSERS, AND THE LANDING GEAR.
THESE COMPONENTS CAN MOVE SUDDENLY WHEN YOU SUPPLY
HYDRAULIC POWER. THIS CAN CAUSE INJURY TO PERSONS AND DAMAGE
TO EQUIPMENT.
WARNING
8. Retract the inboard and outboard spoilers. Refer to 737-300/400/500 AMM 27-61-00 as an accepted
procedure.
9. Put the airplane back to a serviceable condition.
Group 2-59:
WORK PACKAGE 3: EXTERNAL TO THE FUEL TANKS AT THE LEFT AND RIGHT WING FRONT
SPAR - WIRE BUNDLE CLAMP REPLACEMENT AND TEFLON SLEEVE INSTALLATION
1. Get access to the left and right wing front spar by extending  the leading edge slats and Krueger
Flap Numbers 1, 2, 3 and 4. Refer to 737-300/400/500 AMM 27-81-00 as an accepted procedure.
2. RC - Replace wire bundle clamps and install TFE-2X Teflon sleeve under the clamps on the wire
bundle installation along the left wing front spar:
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
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ALERTALERT

### Page 56

a. Group 2-7, 16, 20-21, 23-24, 30, 56-59:
In accordance with FIGURE 30.
b. Group 8-15, 17-19, 22, 25-29, 31-55:
In accordance with FIGURE 31.
3. RC - Replace wire bundle clamps and install TFE-2X Teflon sleeve under the clamps on the wire
bundle installation along the right wing front spar:
a. Group 2-59:
In accordance with FIGURE 32.
KEEP PERSONS AND EQUIPMENT AWAY FROM ALL CONTROL SURFACES
WHEN HYDRAULIC POWER IS SUPPLIED. AILERONS, ELEVATORS, RUDDER,
FLAPS, SLATS, SPOILERS AND STABILIZER ARE FULLY POWERED
SURFACES. INJURY TO PERSONS OR DAMAGE TO EQUIPMENT CAN OCCUR
WHEN HYDRAULIC POWER IS SUPPLIED.
WARNING
MAKE SURE THE ACCESS DOOR FOR THE ENGINE STRUT, THE INBOARD
FAN COWLING, AND THE THRUST REVERSER COWLING ARE CLEAR FROM
MOVEMENT OF THE SLATS. IF THE MOVEMENT OF THE SLATS IS BLOCKED,
IT CAN CAUSE DAMAGE TO THE AIRPLANE.CAUTION
4. Retract the leading edge slats and Krueger Flap Numbers 1, 2, 3 and 4. Refer to 737-300/400/500
AMM 27-81-00 as an accepted procedure.
5. Put the airplane back to a serviceable condition.
Group 2-59:
WORK PACKAGE 4 - EXTERNAL TO THE FUEL TANKS AT THE FORWARD CARGO
COMPARTMENT STATION 540 BULKHEAD - WIRE BUNDLE CLAMP REPLACEMENT AND
TEFLON SLEEVE INSTALLATION
1. Open the forward cargo compartment door. Refer to 737-300/400 /500 AMM 52-31-00 as an
accepted procedure.
2. Remove and keep the forward cargo compartment bulkhead lining  to get access to the Station
540 bulkhead in the forward cargo compartment. Refer to 737-300/400/500 AMM 25-52-81 as an
accepted procedure.
3. RC - Replace wire bundle clamps and install TFE-2X Teflon sleeve under the clamps on the wire
bundle installation along the Station 540 bulkhead in the forward cargo compartment:
a. Group 2, 8-9:
In accordance with FIGURE 33.
b. Group 3, 10-15:
In accordance with FIGURE 34.
c. Group 4-7, 16-32, 37-45, 49-59:
In accordance with FIGURE 35.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
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ALERTALERT

### Page 57

d. Group 33-35:
In accordance with FIGURE 36.
e. Group 36, 46-48:
In accordance with FIGURE 37.
4. Install kept forward cargo compartment bulkhead lining. Refer to 737-300/400/500 AMM 25-52-81
as an accepted procedure.
5. Close the forward cargo compartment door. Refer to 737-300/40 0/500 AMM 52-31-00 as an
accepted procedure.
6. Put the airplane back to a serviceable condition.
Group 2-59:
WORK PACKAGE 5 - EXTERNAL TO THE FUEL TANKS AT THE MAIN WHEEL WELL STATION
663 BULKHEAD - WIRE BUNDLE CLAMP REPLACEMENT AND TEFLON SLEEVE INSTALLATION
1. Open the left and right main landing gear door and install th e main gear ground lock assembly.
Refer to 737-300/400/500 AMM 32-00-01 as an accepted procedure.
2. RC - Replace wire bundle clamps and install TFE-2X Teflon sleeve under the clamps on the wire
bundle installation along the Station 663 bulkhead in the main wheel well:
a. Group 10-11, 16-19, 36-39, 46, 49-50:
In accordance with FIGURE 38.
b. Group 2, 4, 8-9, 12, 20, 40-41, 47, 51, 56:
In accordance with FIGURE 39.
c. Group 13-14, 21-22, 42-44, 48, 52-54:
In accordance with FIGURE 40.
d. Group 5, 15, 23, 55, 57:
In accordance with FIGURE 41.
e. Group 24-27, 33:
In accordance with FIGURE 42.
f. Group 28-29, 34:
In accordance with FIGURE 43.
g. Group 3, 6-7, 30-32, 35, 45, 58-59:
In accordance with FIGURE 44.
3. Remove the main gear ground lock assembly and close the left and right main landing gear door.
Refer to 737-300/400/500 AMM 32-00-01 as an accepted procedure.
4. Put the airplane back to a serviceable condition.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: February 08, 2019
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BOEING SERVICE BULLETIN 737-57A1321
ALERTALERT

### Page 58 (OCR)

BOEING SERVICE BULLETIN 737-57A1321
ALERT  ALERT
This Figure applies only to: Group 2-48, 56-59.
WBL
71.24
WBL
541.69
REAR SPAR
UPPER CHORD
RIB
NO.
RIB
NO. 2
- REAR SPAR WEB
REAR SPAR
LOWER CHORD
INBD  VIEW LOOKING AFT THROUGH ACCESS DOOR NO. 1, 7202
2218491
FIGURE 1: LEFT WING REAR SPAR - FUEL TANK FASTENERS - LOCATION
(SHEET 1 OF 3)
Original Issue: February 08, 2019
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.  68789

### Page 59

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The fastener
quantity or configuration can be different than that shown at the identified locations, thus make sure that all
fasteners at the identified locations are included.
More DataQtyIdentificationNameTaskStep
3-FASTENERLocate1
2-FASTENERLocate2
2-FASTENERLocate3
FIGURE 1: LEFT WING REAR SPAR - FUEL TANK FASTENERS - LOCATION
(SHEET 2 OF 3)
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
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BOEING SERVICE BULLETIN 737-57A1321
ALERTALERT

### Page 60

More DataQtyIdentificationNameTaskStep
10-FASTENERLocate4
10-FASTENERLocate5
FIGURE 1: LEFT WING REAR SPAR - FUEL TANK FASTENERS - LOCATION
(SHEET 3 OF 3)
Export Controlled ECCN: 9E991 - BOEING
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Original Issue: February 08, 2019
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