# Boeing Alert Service Bulletin 737-57A1334: No revision named

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- Document: [Boeing Alert Service Bulletin 737-57A1334](https://openairdocs.org/service-documents/boeing/737-57a1334.md)
- Title as filed: SB-737-57A1334
- Pages: 101
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## Text

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### Page 1

Commercial 
Airplanes
737
Service Bulletin
ALERT
Number: 737-57A1334
Original Issue: September 26, 2017
ATA System: 5743
SUBJECT: WINGS - Landing Gear Attach Fittings - Main Landing Gear Beam Forward Support
Fitting - Inspection and Repair
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 © 2017 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Unpublished Work.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.
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737-57A1334
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3.0

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### Page 3

Table of Contents
S u m m a r y  ...................................................... 5
1. PLANNING INFORMATION ........................................ 9
A . E f f e c t i v i t y  ................................................ 9
1. Airplanes ............................................. 9
2 . S p a r e s  A f f e c t e d  ........................................ 2 2
B. Concurrent Requirements ...................................... 2 2
C. Reason ................................................ 2 2
D. Description .............................................. 2 3
E. Compliance .............................................. 2 4
F . A p p r o v a l  ............................................... 3 3
G. Manpower .............................................. 3 3
H. Weight and Balance Changes .................................... 3 5
I. Electrical Load Data ......................................... 3 5
J . R e f e r e n c e s  .............................................. 3 5
1. Existing Data: ......................................... 3 5
2. Data Supplied with this Service Bulletin: ........................... 3 5
3. Installation Drawings Used in the Preparation of this Service Bulletin: ........... 3 5
K. Publications Affected ........................................ 3 6
L. Interchangeability and Intermixability of Parts ........................... 3 6
M. Software Accomplishment Summary ................................ 3 6
2. MATERIAL INFORMATION ........................................ 3 7
A. Material - Price and Availability ................................... 3 7
B. Industry Support Information .................................... 3 7
C. Parts Necessary for Each Airplane ................................. 3 7
1 . K i t s / P a r t s  ............................................ 3 7
2. Parts and Materials Supplied by the Operator ........................ 3 7
3. Parts Modified and Reidentified ................................ 3 9
4. Parts Removed and Not Replaced .............................. 3 9
D. Parts Necessary to Change Spares ................................. 3 9
E. Special Tooling - Price and Availability ............................... 3 9
F. Special Tooling Necessary to do this Service Bulletin ....................... 3 9
3. ACCOMPLISHMENT INSTRUCTIONS .................................. 4 1
A. GENERAL INFORMATION ..................................... 4 1
B. WORK INSTRUCTIONS ....................................... 4 2
FIGURE 1: LEFT WING - MAIN LANDING GEAR BEAM FORWARD SUPPORT FITTING - REMOVAL OF
FASTENERS [Group 2] .................................... 4 8
FIGURE 2: RIGHT WING - MAIN LANDING GEAR BEAM FORWARD SUPPORT FITTING - REMOVAL
OF FASTENERS [Group 2] .................................. 5 1
FIGURE 3: LEFT WING - MAIN LANDING GEAR BEAM FORWARD SUPPORT FITTING - OPEN HOLE
HFEC INSPECTION [Group 2] ................................ 5 4
FIGURE 4: RIGHT WING - MAIN LANDING GEAR BEAM FORWARD SUPPORT FITTING - OPEN HOLE
HFEC INSPECTION [Group 2] ................................ 5 7
FIGURE 5: LEFT WING - MAIN LANDING GEAR BEAM FORWARD SUPPORT FITTING - SURFACE
HFEC INSPECTION AT EACH FASTENER HOLE WITH FREEZE PLUG [Group 2, Configuration
2 ,  4 ,  6 ]  .............................................. 6 0
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FIGURE 6: RIGHT WING - MAIN LANDING GEAR BEAM FORWARD SUPPORT FITTING - SURFACE
HFEC INSPECTION AT EACH FASTENER HOLE WITH FREEZE PLUG [Group 2, Configuration
2 ,  4 ,  6 ]  .............................................. 6 3
FIGURE 7: LEFT WING - MAIN LANDING GEAR BEAM FORWARD SUPPORT FITTING - FREEZE PLUG
REPAIR [Group 2, Configuration 1, 3, 5] ........................... 6 6
FIGURE 8: RIGHT WING - MAIN LANDING GEAR BEAM FORWARD SUPPORT FITTING - FREEZE
PLUG REPAIR [Group 2, Configuration 1, 3, 5] ........................ 7 1
FIGURE 9: LEFT WING - MAIN LANDING GEAR BEAM FORWARD SUPPORT FITTING - INSTALLATION
OF FASTENERS [Group 2] .................................. 7 6
FIGURE 10: RIGHT WING - MAIN LANDING GEAR BEAM FORWARD SUPPORT FITTING - INSTALLATION
OF FASTENERS [Group 2] .................................. 8 0
APPENDIX A: TABLE 1: OPEN HOLE HFEC INSPECTION ON THE MLG BEAM FORWARD SUPPORT
FITTING WITHOUT A FREEZE PLUG INSTALLED [Group 2, Configuration 1] ...... 8 4
APPENDIX B: TABLE 2: OPEN HOLE AND SURFACE HFEC INSPECTION ON THE MLG BEAM FORWARD
SUPPORT FITTING WITH A FREEZE PLUG INSTALLED [Group 2, Configuration 2] . . . 86
APPENDIX C: TABLE 3: OPEN HOLE HFEC INSPECTION ON THE MLG BEAM FORWARD SUPPORT
FITTING WITHOUT A FREEZE PLUG INSTALLED [Group 2, Configuration 3] ...... 9 0
APPENDIX D: TABLE 4: OPEN HOLE AND SURFACE HFEC INSPECTION ON THE MLG BEAM FORWARD
SUPPORT FITTING WITH A FREEZE PLUG INSTALLED [Group 2, Configuration 4] . . . 92
APPENDIX E: TABLE 5: OPEN HOLE HFEC INSPECTION ON THE MLG BEAM FORWARD SUPPORT
FITTING WITHOUT A FREEZE PLUG INSTALLED  [Group 2, Configuration 5] ...... 9 6
APPENDIX F: TABLE 6: OPEN HOLE AND SURFACE HFEC INSPECTION ON THE MLG BEAM FORWARD
SUPPORT FITTING WITH A FREEZE PLUG INSTALLED [Group 2, Configuration 6] . . . 98
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Commercial 
Airplanes
737
Service Bulletin
ALERT
SummaryNumber: 737-57A1334Original Issue: September 26, 2017
ATA System: 5743
SUBJECT: WINGS - Landing Gear Attach Fittings - Main Landing Gear Beam Forward Support
Fitting - Inspection and Repair
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 detect cracks in the Main Landing Gear (MLG) beam forward support
fitting. If this service bulletin is not done, undetected cracks in the MLG beam forward support fitting can result
in a fuel leak or lead to the inability of a principal structural element to carry limit load, or MLG collapse that
could prevent continued safe flight and landing.
During a repair of the right wing rear spar, one operator reported crack indications in the MLG beam forward
support fitting. Other operators have reported MLG beam forward support fitting cracking around the fastener
locations common to the rear spar web below the upper chord on the inboard side of the Wing Buttock Line
(WBL) 157 rib. Cracks were found on airplanes from 62,706 to 65,827 flight hours and 50,152 to 53,039 flight
cycles. Cracks in the MLG beam forward support fitting at this location are entirely hidden. The forward side of
the fitting (inside fuel tanks) is hidden by sealant and the aft side of the fitting is hidden by the rear spar web
and MLG Beam. MLG beam forward support fitting cracks would not be reliably detected during normal
maintenance therefore requiring additional inspections.
This Service Bulletin gives instructions for the inspection of the MLG beam forward support fitting for any crack
to make sure they are found and repaired before they reach a critical length that could prevent continued safe
flight operation.
Boeing Service Related Problem (SRP) 737-SRP-57-0304 is related to this service bulletin.
Boeing Fleet Team Digest (FTD) 737 FTD 57-16002 is related to this service bulletin.
This table is provided to operators for planning purposes only. Refer to the applicable sections for more
information.
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### Page 6

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 ChangesNoWeight and Balance Change
Paragraph 1.I., Electrical Load DataNoElectrical Load Changed
Paragraph 1.K., Publications AffectedNoPublications 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
Group 1:
Boeing endorses the FAA rules related to Limit of Validity (LOV) and recommends immediate and permanent
removal from service of any airplanes upon reaching the LOV, whether or not it is operated under FAA jurisdiction.
As such, Boeing no longer provides maintenance instructions for airplanes that have accumulated flight cycles
beyond the LOV. Airplanes in Group 1 (line numbers 1-291) have accumulated flight cycles beyond the LOV of
the maintenance program. 14 CFR 121.1115 and 129.115 prohibit operation of an airplane beyond its LOV.
Group 2, Configuration 1, 3, 5:
For airplanes without a freeze plug installed in the inspection area, remove fasteners from the MLG beam forward
support fitting and do an open hole High Frequency Eddy Current (HFEC) inspection for any crack. If no crack
is found, repeat the open hole HFEC inspection. If any crack is found in one fastener hole location, ream the
fastener hole to remove the crack and install a freeze plug. Repeat inspection in new configuration (Group 2,
configuration 2, 4, or 6). If any crack is found in more than one fastener hole location, contact The Boeing
Company for repair instructions and do the repair. Install fasteners.
Group 2, Configuration 2, 4, 6:
For airplanes with a freeze plug installed in the inspection area, do a surface HFEC inspection at the freeze plug
repaired hole. At the locations without a freeze plug, remove fasteners and do open hole HFEC inspections for
any crack. If no crack is found, repeat surface and open hole HFEC inspections. If any crack is found, contact
The Boeing Company for repair instructions and do the repair. Install fasteners.
EFFECTIVITY
All 737-100, 737-200, 737-200C, 737-300, 737-400, and 737-500 airplanes. Refer to Paragraph 1.A.1., Airplanes,
for the list of affected airplanes.
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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.
Refer to Paragraph 1.E., Compliance.
INDUSTRY SUPPORT INFORMATION
Boeing warranty remedies are not available for the inspection and repair procedures 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.
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### Page 8 (OCR)

BOEING SERVICE BULLETIN 737-57A1334
ALERT  ALERT
FOR AIRPLANES WITHOUT FREEZE
PLUGS, DO AN OPEN HOLE HIGH
FREQUENCY EDDY CURRENT (HFEC)
INSPECTION FOR ANY CRACK.
FOR AIRPLANES WITH FREEZE PLUGS
INSTALLED, DO A SURFACE HFEC
INSPECTION ON FREEZE PLUGGED
HOLES AND AN OPEN HOLE HFEC
INSPECTION ON NON-FREEZE PLUGGED
HOLES FOR ANY CRACK.
WBL
135.50
WBL
157.00
LEFT WING SHOWN RIGHT WING OPPOSITE  2577571
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### Page 9

Commercial 
Airplanes
737
Service Bulletin
ALERT
Number: 737-57A1334
Original Issue: September 26, 2017
ATA System: 5743
SUBJECT: WINGS - Landing Gear Attach Fittings - Main Landing Gear Beam Forward Support
Fitting - Inspection and Repair
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
This service bulletin is applicable to all 737-100/200/200C/300/400/500 Airplanes in 2 Groups.
The Variable Numbers and Group Information for the applicable airplanes is given below.
Refer to Service Bulletin Index D6-19567 Part 3 for Airplane Variable Number, Line Number, and
Serial Number data.
DESCRIPTIONCONFIGURATIONGROUP
Airplane line numbers 1 - 291-1
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DESCRIPTIONCONFIGURATIONGROUP
Airplane line numbers 292 - 3132-2
Airplanes that have not done the rear spar web repair and
replacement in accordance with 737-300/400/500 SRM 57-20-10,
Repair 5 or a Boeing Organization Designation Authorization (ODA)
FAA 8100-9 Form and that have not installed a freeze plug for any
of the 14 fasteners on the inboard side of the MLG beam forward
support fitting common only to the rear spar web in the inspection
area.
1
Airplanes that have not done the rear spar web repair and
replacement in accordance with 737-300/400/500 SRM 57-20-10,
Repair 5 or a Boeing ODA FAA 8100-9 Form and that have installed
a freeze plug for any of the 14 fasteners on the inboard side of the
MLG beam forward support fitting common only to the rear spar web
in the inspection area.
2
Airplanes that have done the rear spar web repair and replacement
in accordance with 737-300/400/500 SRM 57-20-10, Repair 5 or a
Boeing ODA FAA 8100-9 Form and that have not installed a freeze
plug for any of the 14 fasteners on the inboard side of the MLG beam
forward support fitting common only to the rear spar web in the
inspection area.
3
Airplanes that have done the rear spar web repair and replacement
in accordance with 737-300/400/500 SRM 57-20-10, Repair 5 or a
Boeing ODA FAA 8100-9 Form and that have installed a freeze plug
for any of the 14 fasteners on the inboard side of the MLG beam
forward support fitting common only to the rear spar web in the
inspection area.
4
Airplanes that have replaced the MLG beam forward support fitting
and installed a wing rear spar chord replacement in accordance with
737-300/400/500 SRM 57-20-10, Repair 4 or a Boeing ODA FAA
8100-9 Form and that have not installed a freeze plug for any of the
14 fasteners on the inboard side of the MLG beam forward support
fitting common only to the rear spar web in the inspection area.
5
Airplanes that have replaced the MLG beam forward support fitting
and installed a wing rear upper spar chord replacement in accordance
with 737-300/400/500 SRM 57-20-10, Repair 4 or a Boeing ODA
FAA 8100-9 Form and that have installed a freeze plug for any of the
14 fasteners on the inboard side of the MLG beam forward support
fitting common only to the rear spar web in the inspection area.
6
Airplane Models:
737-100, 737-200, 737-200C, 737-300, 737-400, 737-500
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GroupVariable Number
1PA001 - PA022
1PA099
1PA231 - PA232
1PC001 - PC005
1PG001 - PG075
1PG199
1PG201 - PG230
1PG251 - PG255
1PG271 - PG279
1PG301 - PG314
1PG331 - PG332
1PG351 - PG356
1PG375
1PG401 - PG403
1PG431 - PG442
1PG471 - PG475
1PG501 - PG505
1PG571 - PG583
2PG584 - PG586
1PG621 - PG630
1PG651 - PG652
1PG701 - PG705
2PH001
2PH011 - PH013
2PH021 - PH024
1PH701 - PH715
1PH731 - PH732
1PH741 - PH742
2PH743
1PJ001 - PJ002
2PJ003 - PJ009
1PJ031 - PJ032
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GroupVariable Number
1PJ071 - PJ072
1PJ101 - PJ104
2PJ105 - PJ119
2PJ201 - PJ219
2PJ301 - PJ302
2PJ551 - PJ561
2PJ601 - PJ615
2PJ811
2PJ816 - PJ817
2PK026 - PK029
2PK041 - PK053
2PK061 - PK070
2PK081 - PK082
2PK091 - PK099
2PK101 - PK103
2PK111 - PK120
2PK141 - PK146
2PK201 - PK204
2PK211 - PK223
2PK231 - PK241
2PK251 - PK258
2PK271 - PK274
2PK281 - PK289
2PK291
2PK301 - PK318
2PK341
2PK351 - PK361
2PK391
2PK431 - PK433
2PK451 - PK452
2PK461 - PK469
2PK495
2PK501 - PK504
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GroupVariable Number
2PK511 - PK515
2PK519
2PK521 - PK528
2PK541 - PK565
2PK581
2PK591 - PK599
2PK601 - PK617
2PK621 - PK637
2PK641 - PK642
2PK661 - PK666
2PK671 - PK681
2PK691 - PK697
2PK711 - PK716
2PK731 - PK765
2PK771 - PK779
2PK801 - PK804
2PK819 - PK827
2PK830
2PK861 - PK863
2PK871 - PK874
2PK881 - PK884
2PK901 - PK938
2PK971 - PK974
2PL001 - PL028
2PL061
2PL081
2PL101 - PL113
2PL151
2PL171 - PL172
2PL201 - PL203
2PL221
2PL401 - PL417
2PL421
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GroupVariable Number
2PL441
2PL451 - PL456
2PL471
2PL491
2PL501 - PL506
2PL551 - PL562
2PL581
2PL601 - PL603
2PL611
2PL621 - PL626
2PL631 - PL632
1PL711 - PL712
1PL716
2PL717 - PL747
2PL756
2PL758
2PL761 - PL770
2PL781 - PL788
2PL793
1PL801 - PL803
2PM001 - PM006
2PM016 - PM017
2PM021 - PM023
2PM051 - PM066
2PM101 - PM119
2PM141 - PM142
2PM171
2PM181
2PM251 - PM255
2PM281 - PM283
2PM381 - PM399
2PM401 - PM417
2PM541 - PM564
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GroupVariable Number
2PN001 - PN002
2PN021 - PN043
2PN081 - PN086
2PN101 - PN117
2PN131 - PN163
2PN401 - PN420
2PN431 - PN433
2PN451 - PN456
2PN471 - PN474
2PN481
2PN491 - PN493
2PN501 - PN502
2PN511 - PN512
2PN521
2PP001 - PP054
2PP101 - PP169
2PP181 - PP199
2PP201 - PP205
2PP221
2PP231 - PP243
2PP281 - PP286
2PP301 - PP305
2PP351 - PP353
2PP376 - PP384
2PP391 - PP393
2PP401 - PP440
2PP471 - PP475
2PP501 - PP522
2PP631 - PP634
2PP651 - PP652
2PP671 - PP699
2PP701 - PP733
2PP771 - PP779
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GroupVariable Number
2PP801 - PP808
2PP821 - PP827
2PP831 - PP848
2PP851 - PP852
2PP861 - PP877
2PP891 - PP899
2PP901 - PP936
2PP946 - PP948
2PP951 - PP952
2PP961 - PP967
2PP981 - PP991
2PP993
2PQ001 - PQ016
2PQ026 - PQ041
2PQ051 - PQ092
2PQ101 - PQ199
2PQ201 - PQ202
2PQ221 - PQ237
2PQ241 - PQ243
2PQ251 - PQ267
2PQ281 - PQ299
2PQ301 - PQ307
2PQ331 - PQ332
2PQ341 - PQ348
2PQ361 - PQ373
2PQ391 - PQ395
2PQ401 - PQ418
2PQ421
2PQ431 - PQ438
2PQ447 - PQ448
2PQ451
2PQ454
2PQ471 - PQ475
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GroupVariable Number
2PQ479 - PQ481
2PQ486 - PQ487
2PQ491 - PQ493
2PQ771 - PQ772
2PQ791 - PQ793
2PQ801 - PQ805
2PQ931 - PQ935
2PQ951
2PQ971 - PQ997
2PR001 - PR017
2PR021 - PR034
2PR041 - PR045
2PR061 - PR072
2PR077 - PR082
2PR091 - PR092
2PR096
2PR101
2PR121 - PR122
2PR131 - PR132
2PR141 - PR143
2PR161 - PR172
2PR181
2PS601 - PS631
2PS636 - PS638
2PS641 - PS644
2PS651 - PS657
2PS666 - PS669
2PS691 - PS692
2PS701 - PS706
2PS751 - PS799
2PS811
2PS836 - PS837
2PS841 - PS846
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GroupVariable Number
2PS851 - PS852
2PS856
2PS861 - PS863
2PS866 - PS868
2PS871 - PS874
2PS896 - PS897
2PS901 - PS941
2PS956 - PS957
2PS961 - PS963
2PS971 - PS978
2PT001 - PT015
2PT021 - PT031
2PT041 - PT064
2PT101 - PT105
2PT121 - PT138
2PT146 - PT148
2PT161 - PT170
2PT181 - PT188
2PT211 - PT220
2PT295
2PT301 - PT309
2PT331 - PT360
2PT381 - PT399
2PT401 - PT438
2PT501 - PT517
2PT561 - PT565
2PT581 - PT586
2PT611 - PT621
2PT641 - PT644
2PT651 - PT656
2PT671 - PT672
2PT681 - PT685
2PT701 - PT703
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GroupVariable Number
2PT716 - PT717
2PT721 - PT725
2PT801 - PT834
2PT851 - PT854
2PT871 - PT886
2PT901 - PT930
2PT971 - PT973
2PT981 - PT985
2PT996
2PU001 - PU025
2PU301
2PU311 - PU313
2PV001 - PV055
2PV201 - PV209
2PV226 - PV229
2PV231 - PV237
2PV271 - PV272
2PV281 - PV287
2PV296
2PV301 - PV302
2PV351
2PV356 - PV357
2PW001 - PW054
2PW061 - PW068
2PW072
2PW086 - PW088
2PW091 - PW094
2PW101 - PW102
2PW106
2PW111 - PW120
2PW156 - PW157
2PW161 - PW171
2PW201 - PW252
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GroupVariable Number
2PW261 - PW268
2PW271 - PW276
2PW278
2PW281 - PW293
2PW296
2PW301 - PW327
2PW401 - PW408
2PW411 - PW418
2PW421 - PW424
2PW431 - PW435
2PW441 - PW450
2PW461 - PW467
2PW501 - PW504
2PW511 - PW522
2PW524 - PW550
2PW556 - PW557
2PW561 - PW564
2PW571 - PW576
2PW591 - PW596
2PW611 - PW622
2PW631 - PW637
2PW661 - PW662
2PW681 - PW683
2PW701 - PW702
2PW711 - PW717
2PW741 - PW742
2PW761
2PW771
2PW831
2PW851 - PW856
1PX071
1PX701
1PY001 - PY008
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GroupVariable Number
1PY021
2PY022
1PY031
2PY036 - PY037
2PY046 - PY048
2PY051 - PY053
2PY056 - PY057
2PY101 - PY103
2PY111 - PY113
2PY131 - PY135
2PY141 - PY143
2PY151 - PY154
2PY156 - PY157
2PY161 - PY162
2PY166
2PY191
2PY201
2PY221 - PY222
2PY231
2PY241 - PY244
2PY270 - PY275
2PY281
2PY286
1PY301 - PY304
1PY321 - PY323
1PY341 - PY346
1PY361 - PY362
1PY381
2PY401
2PY409 - PY411
2PY421 - PY422
2PY441
2PY451
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GroupVariable Number
2PY461 - PY463
2PY591 - PY595
2PY611 - PY612
2PY621
2PY631
2PY651
2PY671 - PY672
2PY721
2PY741
2. Spares Affected
None.
B. Concurrent Requirements
None.
C. Reason
Accomplishment of this service bulletin will detect cracks in the Main Landing Gear (MLG) beam forward
support fitting. If this service bulletin is not done, undetected cracks in the MLG beam forward support
fitting can lead to the inability of a principal structural element to carry limit load, MLG collapse, or result
in a fuel leak that could prevent continued safe flight and landing.
During a repair of the right wing rear spar, one operator reported crack indications in the MLG beam
forward support fitting. Other operators have reported MLG beam forward support fitting cracking around
the fastener locations common to the rear spar web below the upper chord on the inboard side of the
Wing Buttock Line (WBL) 157 rib. Cracks were found on airplanes from 62,706 to 65,827 flight hours
and 50,152 to 53,039 flight cycles. Cracks in the MLG beam forward support fitting at this location are
entirely hidden. The forward side of the fitting (inside fuel tanks) is hidden by sealant and the aft side
of the fitting is hidden by the rear spar web and MLG Beam. MLG beam forward support fitting cracks
would not be reliably detected during normal maintenance therefore requiring additional inspections.
This Service Bulletin gives instructions for the inspection of the MLG beam forward support fitting for
any crack to make sure they are found and repaired before they reach a critical length that could prevent
continued safe flight operation.
Boeing Service Related Problem (SRP) 737-SRP-57-0304 is related to this service bulletin.
Boeing Fleet Team Digest (FTD) 737 FTD 57-16002 is related to this service bulletin.
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D. Description
Group 1:
Boeing endorses the FAA rules related to Limit of Validity (LOV) and recommends immediate and
permanent removal from service of any airplanes upon reaching the LOV, whether or not it is operated
under FAA jurisdiction. As such, Boeing no longer provides maintenance instructions for airplanes that
have accumulated flight cycles beyond the LOV. Airplanes in Group 1 (line numbers 1-291) have
accumulated flight cycles beyond the LOV of the maintenance program. 14 CFR 121.1115 and 129.115
prohibit operation of an airplane beyond its LOV.
Group 2, Configuration 1, 3, 5:
For airplanes without a freeze plug installed in the inspection area, remove fasteners from the MLG
beam forward support fitting and do an open hole High Frequency Eddy Current (HFEC) inspection
for any crack. If no crack is found, repeat the open hole HFEC inspection. If any crack is found in one
fastener hole location, ream the fastener hole to remove the crack and install a freeze plug. Repeat
inspection in new configuration (Group 2, configuration 2, 4, or 6). If any crack is found in more than
one fastener hole location, contact The Boeing Company for repair instructions and do the repair. Install
fasteners.
Group 2, Configuration 2, 4, 6:
For airplanes with a freeze plug installed in the inspection area, do a surface HFEC inspection at the
freeze plug repaired hole. At the locations without a freeze plug, remove fasteners and do open hole
HFEC inspections for any crack. If no crack is found, repeat surface and open hole HFEC inspections.
If any crack is found, contact The Boeing Company for repair instructions and do the repair. Install
fasteners.
The work in this service bulletin is done in the maintenance zone(s) given below.
Group 1:
Affected Maintenance Zones
ZoneModel
3-5, 4-5737-100, 737-200, 737-200C
Group 2:
Affected Maintenance Zones
ZoneModel
3-5, 4-5737-200, 737-200C
Group 2:
Affected Maintenance Zones
ZoneModel
305, 405737-300, 737-400, 737-500
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### Page 24

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.
Accomplish the required actions, based on the applicable conditions in Tables 1 through 6, in accordance
with Paragraph 3. Accomplishment Instructions.
When more than one OPTION is given for a CONDITION, do only one of the OPTION numbers. When
more than one ACTION is given for a CONDITION number or an OPTION number, do all of the ACTION
numbers for that CONDITION number or OPTION number.
Logic diagrams showing compliance tasks and compliance times are included as an aid in APPENDIX
A, APPENDIX B, APPENDIX C, APPENDIX D, APPENDIX E and APPENDIX F.
Group 1:
Boeing endorses the FAA rules related to Limit of Validity (LOV) and recommends immediate and
permanent removal from service of any airplanes upon reaching the LOV, whether or not it is operated
under FAA jurisdiction. As such, Boeing no longer provides maintenance instructions for airplanes that
have accumulated flight cycles beyond the LOV. Airplanes in Group 1 (line numbers 1-291) have
accumulated flight cycles beyond the LOV of the maintenance program. 14 CFR 121.1115 and 129.115
prohibit operation of an airplane beyond its LOV.
Group 2, Configuration 1:
Table 1: Open hole High Frequency Eddy Current (HFEC) inspection on the MLG beam forward support
fitting without a freeze plug installed
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
-Within 4,500
flight cycles af-
ter the original
issue date of
this service bul-
letin.
Before 30,000
total flight cy-
cles.
Do PART 2: OPEN HOLE
HFEC INSPECTION OF
THE MLG BEAM FOR-
WARD SUPPORT FIT-
TING AT FASTENER
HOLES WITHOUT A
FREEZE PLUG IN-
STALLED for any crack.
All Airplanes
-Before further flight.Do PART 4: CRACK RE-
MOVAL AND OPEN
HOLE HFEC INSPEC-
TION OF THE MLG
BEAM FORWARD SUP-
PORT FITTING for any
crack.
CONDITION 1: ANY
CRACK FOUND AT ANY
ONE FASTENER HOLE IN
THE INSPECTION AREA
-Before further flight.Contact The Boeing
Company for repair in-
structions and do the re-
pair.
CONDITION 1.1: ANY RE-
MAINING CRACK FOUND
AFTER THE HOLE DIAM-
ETER WAS INCREASED
TO THE MAXIMUM
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### Page 25

Group 2, Configuration 1:
Table 1: Open hole High Frequency Eddy Current (HFEC) inspection on the MLG beam forward support
fitting without a freeze plug installed
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
-Before further flight.Do PART 5: FREEZE
PLUG REPAIR (a)
CONDITION 1.2: NO RE-
MAINING CRACK FOUND
-Before further flight.Contact The Boeing
Company for repair in-
structions and do the re-
pair.
CONDITION 2: ANY
CRACK FOUND AT MORE
THAN ONE FASTENER
HOLE IN THE INSPEC-
TION AREA
15,000 flight cycles-Repeat PART 2: OPEN
HOLE HFEC INSPEC-
TION OF THE MLG
BEAM FORWARD SUP-
PORT FITTING AT FAS-
TENER HOLES WITH-
OUT A FREEZE PLUG
INSTALLED for any
crack.
CONDITION 3: NO
CRACK FOUND
(a) After accomplishment of PART 5: FREEZE PLUG REPAIR the airplane will be in Group 2, Configuration
2. Refer to Table 2 for additional actions.
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### Page 26

Group 2, Configuration 2:
Table 2: Open hole and surface High Frequency Eddy Current (HFEC) inspection on the MLG beam
forward support fitting with a freeze plug installed
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
-Within 4,500
flight cycles af-
ter the original
issue date of
this service bul-
letin.
Before 30,000
total flight cy-
cles.
ACTION 1: Do PART 2:
OPEN HOLE HFEC IN-
SPECTION OF THE MLG
BEAM FORWARD SUP-
PORT FITTING AT FAS-
TENER HOLES WITH-
OUT A FREEZE PLUG
INSTALLED for any
crack.
Existing freeze plug in the
inspection area that was
not installed in accordance
with this service bulletin
-4,500 flight cy-
cles after the
original issue
date of this ser-
vice bulletin.
Within 25,000
flight cycles af-
ter the installa-
tion of the
freeze plug re-
pair.
ACTION 2: Do PART 3:
SURFACE HFEC IN-
SPECTION OF THE MLG
BEAM FORWARD SUP-
PORT FITTING AT FAS-
TENER HOLE WITH A
FREEZE PLUG IN-
STALLED for any crack.
(a)
15,000 flight cycles-ACTION 1: Repeat PART
2: OPEN HOLE HFEC
INSPECTION OF THE
MLG BEAM FORWARD
SUPPORT FITTING AT
FASTENER HOLES
WITHOUT A FREEZE
PLUG INSTALLED for
any crack.
Freeze plug installed in ac-
cordance with this service
bulletin
-Within 25,000 flight cycles after
the installation of the freeze plug.
ACTION 2: Do PART 3:
SURFACE HFEC IN-
SPECTION OF THE MLG
BEAM FORWARD SUP-
PORT FITTING AT FAS-
TENER HOLE WITH A
FREEZE PLUG IN-
STALLED for any crack.
-Before further flight.Contact The Boeing
Company for repair in-
structions and do the re-
pair.
CONDITION 4: ANY
CRACK FOUND DURING
PART 2 INSPECTION
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### Page 27

Group 2, Configuration 2:
Table 2: Open hole and surface High Frequency Eddy Current (HFEC) inspection on the MLG beam
forward support fitting with a freeze plug installed
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
15,000 flight cycles-Repeat PART 2: OPEN
HOLE HFEC INSPEC-
TION OF THE MLG
BEAM FORWARD SUP-
PORT FITTING AT FAS-
TENER HOLES WITH-
OUT A FREEZE PLUG
INSTALLED for any
crack.
CONDITION 5: NO
CRACK FOUND DURING
PART 2 INSPECTION
-Before further flight.Contact The Boeing
Company for repair in-
structions and do the re-
pair.
CONDITION 6: ANY
CRACK FOUND DURING
PART 3 INSPECTION
4,000 flight cycles-Repeat PART 3: SUR-
FACE HFEC INSPEC-
TION OF THE MLG
BEAM FORWARD SUP-
PORT FITTING AT FAS-
TENER HOLE WITH A
FREEZE PLUG IN-
STALLED for any crack.
CONDITION 7: NO
CRACK FOUND DURING
PART 3 INSPECTION
(a) This service bulletin requires a surface HFEC inspection of the MLG beam forward support fitting at the
fastener hole with an existing freeze plug repair. This requirement does not supersede any existing 8100-
9 inspection requirements on the freeze plug repair.
Group 2, Configuration 3:
Table 3: Open hole High Frequency Eddy Current (HFEC) inspection on the MLG beam forward support
fitting without a freeze plug installed
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
-Within 15,000
flight cycles af-
ter installation of
the rear spar
web repair or
within 4,500
flight cycles af-
ter the original
issue date of
this service bul-
letin, whichever
occurs later.
Before 30,000
total flight cy-
cles.
Do PART 2: OPEN HOLE
HFEC INSPECTION OF
THE MLG BEAM FOR-
WARD SUPPORT FIT-
TING AT FASTENER
HOLES WITHOUT A
FREEZE PLUG IN-
STALLED for any crack.
All Airplanes
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### Page 28

Group 2, Configuration 3:
Table 3: Open hole High Frequency Eddy Current (HFEC) inspection on the MLG beam forward support
fitting without a freeze plug installed
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
-Before further flight.Do PART 4: CRACK RE-
MOVAL AND OPEN
HOLE HFEC INSPEC-
TION OF THE MLG
BEAM FORWARD SUP-
PORT FITTING for any
crack.
CONDITION 1: ANY
CRACK FOUND AT ANY
ONE FASTENER HOLE IN
THE INSPECTION AREA
-Before further flight.Contact The Boeing
Company for repair in-
structions and do the re-
pair.
CONDITION 1.1: ANY RE-
MAINING CRACK FOUND
AFTER THE HOLE DIAM-
ETER WAS INCREASED
TO THE MAXIMUM
-Before further flight.Do PART 5: FREEZE
PLUG REPAIR. (a)
CONDITION 1.2: NO RE-
MAINING CRACK FOUND
-Before further flight.Contact The Boeing
Company for repair in-
structions and do the re-
pair.
CONDITION 2: ANY
CRACK FOUND AT MORE
THAN ONE FASTENER
HOLE IN THE INSPEC-
TION AREA
15,000 flight cycles-Repeat PART 2: OPEN
HOLE HFEC INSPEC-
TION OF THE MLG
BEAM FORWARD SUP-
PORT FITTING AT FAS-
TENER HOLES WITH-
OUT A FREEZE PLUG
INSTALLED for any
crack.
CONDITION 3: NO
CRACK FOUND
(a) After accomplishment of PART 5: FREEZE PLUG REPAIR the airplane will be in Group 2, Configuration
4. Refer to Table 4 for additional actions.
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### Page 29

Group 2, Configuration 4:
Table 4: Open hole and surface High Frequency Eddy Current (HFEC) inspection on the MLG beam
forward support fitting with a freeze plug installed
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
-Within 15,000
flight cycles af-
ter the installa-
tion of approved
rear spar web
repair or within
4,500 flight cy-
cles after the
original issue
date of this ser-
vice bulletin,
whichever oc-
curs later.
Before 30,000
total flight cy-
cles.
ACTION 1: Do PART 2:
OPEN HOLE HFEC IN-
SPECTION OF THE MLG
BEAM FORWARD SUP-
PORT FITTING AT FAS-
TENER HOLES WITH-
OUT A FREEZE PLUG
INSTALLED for any
crack.
Existing freeze plug in the
inspection area that was
not installed in accordance
with this service bulletin
-4,500 flight cy-
cles after the
original issue
date of this ser-
vice bulletin.
Within 25,000
flight cycles af-
ter the installa-
tion of the
freeze plug.
ACTION 2: Do PART 3:
SURFACE HFEC IN-
SPECTION OF THE MLG
BEAM FORWARD SUP-
PORT FITTING AT FAS-
TENER HOLE WITH A
FREEZE PLUG IN-
STALLED for any crack.
(a)
15,000 flight cycles-ACTION 1: Repeat PART
2: OPEN HOLE HFEC
INSPECTION OF THE
MLG BEAM FORWARD
SUPPORT FITTING AT
FASTENER HOLES
WITHOUT A FREEZE
PLUG INSTALLED for
any crack.
Freeze plug installed in ac-
cordance with this service
bulletin
-Within 25,000 flight cycles after
the installation of the freeze plug.
ACTION 2: Do PART 3:
SURFACE HFEC IN-
SPECTION OF THE MLG
BEAM FORWARD SUP-
PORT FITTING AT FAS-
TENER HOLE WITH A
FREEZE PLUG IN-
STALLED for any crack.
-Before further flight.Contact The Boeing
Company for repair in-
structions and do the re-
pair
CONDITION 4: ANY
CRACK FOUND DURING
PART 2 INSPECTION
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### Page 30

Group 2, Configuration 4:
Table 4: Open hole and surface High Frequency Eddy Current (HFEC) inspection on the MLG beam
forward support fitting with a freeze plug installed
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
15,000 flight cycles-Repeat PART 2: OPEN
HOLE HFEC INSPEC-
TION OF THE MLG
BEAM FORWARD SUP-
PORT FITTING AT FAS-
TENER HOLES WITH-
OUT A FREEZE PLUG
INSTALLED for any
crack.
CONDITION 5: NO
CRACK FOUND DURING
PART 2 INSPECTION
-Before further flight.Contact The Boeing
Company for repair in-
structions and do the re-
pair.
CONDITION 6: ANY
CRACK FOUND DURING
PART 3 INSPECTION
4,000 flight cycles-Repeat PART 3: SUR-
FACE HFEC INSPEC-
TION OF THE MLG
BEAM FORWARD SUP-
PORT FITTING AT FAS-
TENER HOLE WITH A
FREEZE PLUG IN-
STALLED for any crack.
CONDITION 7: NO
CRACK FOUND DURING
PART 3 INSPECTION
(a) This service bulletin requires a surface HFEC inspection of the MLG beam forward support fitting at the
fastener hole with an existing freeze plug repair. This requirement does not supersede any existing 8100-
9 inspection requirements on the freeze plug repair.
Group 2, Configuration 5:
Table 5: Open hole High Frequency Eddy Current (HFEC) inspection on the MLG beam forward support
fitting without a freeze plug installed
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
-Within 4,500
flight cycles af-
ter the original
issue date of
this service bul-
letin.
Within 30,000
flight cycles af-
ter the installa-
tion of MLG fit-
ting and wing
rear spar upper
chord.
Do PART 2: OPEN HOLE
HFEC INSPECTION OF
THE MLG BEAM FOR-
WARD SUPPORT FIT-
TING AT FASTENER
HOLES WITHOUT A
FREEZE PLUG IN-
STALLED for any crack.
All Airplanes
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### Page 31

Group 2, Configuration 5:
Table 5: Open hole High Frequency Eddy Current (HFEC) inspection on the MLG beam forward support
fitting without a freeze plug installed
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
-Before further flight.Do PART 4: CRACK RE-
MOVAL AND OPEN
HOLE HFEC INSPEC-
TION OF THE MLG
BEAM FORWARD SUP-
PORT FITTING for any
crack.
CONDITION 1: ANY
CRACK FOUND AT ANY
ONE FASTENER HOLE IN
THE INSPECTION AREA
-Before further flight.Contact The Boeing
Company for repair in-
structions and do the re-
pair.
CONDITION 1.1: ANY RE-
MAINING CRACK FOUND
AFTER THE HOLE DIAM-
ETER WAS INCREASED
TO THE MAXIMUM
-Before further flight.Do PART 5: FREEZE
PLUG REPAIR. (a)
CONDITION 1.2: NO RE-
MAINING CRACK FOUND
-Before further flight.Contact The Boeing
Company for repair in-
structions and do the re-
pair.
CONDITION 2: ANY
CRACK FOUND AT MORE
THAN ONE FASTENER
HOLE IN THE INSPEC-
TION AREA.
15,000 flight cycles-Repeat PART 2: OPEN
HOLE HFEC INSPEC-
TION OF THE MLG
BEAM FORWARD SUP-
PORT FITTING AT FAS-
TENER HOLES WITH-
OUT A FREEZE PLUG
INSTALLED for any
crack.
CONDITION 3: NO
CRACK FOUND
(a) After accomplishment of PART 5: FREEZE PLUG REPAIR the airplane will be in Group 2, Configuration
6. Refer to Table 6 for additional actions.
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### Page 32

Group 2, Configuration 6:
Table 6: Open hole and surface High Frequency Eddy Current (HFEC) inspection on the MLG beam
forward support fitting with a freeze plug installed
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
-Within 4,500
flight cycles af-
ter the original
issue date of
this service bul-
letin.
Within 30,000
flight cycles af-
ter the installa-
tion of MLG fit-
ting and wing
rear spar upper
chord.
ACTION 1: Do PART 2:
OPEN HOLE HFEC IN-
SPECTION OF THE MLG
BEAM FORWARD SUP-
PORT FITTING AT FAS-
TENER HOLES WITH-
OUT A FREEZE PLUG
INSTALLED for any
crack.
Existing freeze plug in the
inspection area that was
not installed in accordance
with this service bulletin
-4,500 flight cy-
cles after the
original issue
date of this ser-
vice bulletin.
Within 25,000
flight cycles af-
ter the installa-
tion of the
freeze plug.
ACTION 2: Do PART 3:
SURFACE HFEC IN-
SPECTION OF THE MLG
BEAM FORWARD SUP-
PORT FITTING AT FAS-
TENER HOLE WITH A
FREEZE PLUG IN-
STALLED for any crack.
(a)
15,000 flight cycles-ACTION 1: Repeat PART
2: OPEN HOLE HFEC
INSPECTION OF THE
MLG BEAM FORWARD
SUPPORT FITTING AT
FASTENER HOLES
WITHOUT A FREEZE
PLUG INSTALLED for
any crack.
Freeze plug installed in ac-
cordance with this service
bulletin
-Within 25,000 flight cycles after
the installation of the freeze plug.
ACTION 2: Do PART 3:
SURFACE HFEC IN-
SPECTION OF THE MLG
BEAM FORWARD SUP-
PORT FITTING AT FAS-
TENER HOLE WITH A
FREEZE PLUG IN-
STALLED for any crack.
-Before further flight.Contact The Boeing
Company for repair in-
structions and do the re-
pair
CONDITION 4: ANY
CRACK FOUND DURING
PART 2 INSPECTION
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### Page 33

Group 2, Configuration 6:
Table 6: Open hole and surface High Frequency Eddy Current (HFEC) inspection on the MLG beam
forward support fitting with a freeze plug installed
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
15,000 flight cycles-Repeat PART 2: OPEN
HOLE HFEC INSPEC-
TION OF THE MLG
BEAM FORWARD SUP-
PORT FITTING AT FAS-
TENER HOLES WITH-
OUT A FREEZE PLUG
INSTALLED for any
crack.
CONDITION 5: NO
CRACK FOUND DURING
PART 2 INSPECTION
-Before further flight.Contact The Boeing
Company for repair in-
structions and do the re-
pair.
CONDITION 6: ANY
CRACK FOUND DURING
PART 3 INSPECTION
4,000 flight cycles-Repeat PART 3: SUR-
FACE HFEC INSPEC-
TION OF THE MLG
BEAM FORWARD SUP-
PORT FITTING AT FAS-
TENER HOLE WITH A
FREEZE PLUG IN-
STALLED for any crack.
CONDITION 7: NO
CRACK FOUND DURING
PART 3 INSPECTION
(a) This service bulletin requires a surface HFEC inspection of the MLG beam forward support fitting at the
fastener hole with an existing freeze plug repair. This requirement does not supersede any existing 8100-
9 inspection requirements on the freeze plug repair.
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 inspection and repair 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:
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• 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 2, Configuration 1, 3, 5:
Elapsed HoursTask HoursNumber of PersonsTask
23.0039.004Open Access
0.500.501FIGURE 1
0.500.501FIGURE 2
1.001.001FIGURE 3
1.001.001FIGURE 4
(a)(a)(a)PART 4
0.100.101FIGURE 5
0.100.101FIGURE 6
0.100.101FIGURE 7
0.100.101FIGURE 8
0.500.501FIGURE 9
0.500.501FIGURE 10
23.0039.004Close Access
50.4082.40TOTAL FOR EACH AIRPLANE
(a) Hours for repair are dependant on inspection findings and are not included.
Group 2, Configuration 2, 4, 6:
Elapsed HoursTask HoursNumber of PersonsTask
23.0039.004Open Access
0.500.501FIGURE 1
0.500.501FIGURE 2
1.001.001FIGURE 3
1.001.001FIGURE 4
0.100.101FIGURE 5
0.100.101FIGURE 6
0.500.501FIGURE 9
0.500.501FIGURE 10
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Group 2, Configuration 2, 4, 6:
Elapsed HoursTask HoursNumber of PersonsTask
23.0039.004Close Access
50.2082.20TOTAL FOR EACH AIRPLANE
H. Weight and Balance Changes
None.
I. Electrical Load Data
Not applicable.
J. References
1. Existing Data:
a. Boeing Service Related Problem (SRP) 737-SRP-57-0304
b. Service Bulletin Index D6-19567
c. Standard Overhaul Practices Manual (SOPM) 20-42-05, 20-44-04, 20-50-01, 20-50-19
d. 737 Fleet Team Digest (FTD) 57-16002
e. 737 Non-Destructive Testing (NDT) Manual Part 6, 51-00-00
f. 737-100/200 Aircraft Maintenance Manual (AMM) 27-11-00, 27-51-00, 28-10-00, 28-11-00,
28-23-00, 32-00-01, 51-31-00, 57-15-00
g. 737-100/200 Structural Repair Manual (SRM) 51-10-09, 51-40-02
h. 737-300/400/500 Aircraft Maintenance Manual (AMM) 27-11-00, 27-51-00, 28-10-00, 28-11-00,
28-23-00, 32-00-01, 51-31-00, 57-15-00
i. 737-300 Structural Repair Manual (SRM) 51-20-10, 51-40-02
j. 737-400 Structural Repair Manual (SRM) 51-20-10, 51-40-02
k. 737-500 Structural Repair Manual (SRM) 51-20-10, 51-40-02
2. Data Supplied with this Service Bulletin:
None.
3. Installation Drawings Used in the Preparation of this Service Bulletin:
TitleDrawing Number
REAR SPAR INSTALLATION - WING65-45321
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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:
None.
2. Damage Tolerance Based Structural Inspections:
Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue
Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the
Maintenance Program. This service bulletin affects FCS but no new DTIs are necessary.
L. Interchangeability and Intermixability of Parts
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 inspection and repair procedures given in this
service bulletin.
C. Parts Necessary for Each Airplane
1. Kits/Parts
None.
2. Parts and Materials Supplied by the Operator
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.
Group 2, Configuration 1, 3, 5:
NotesNameQTYPart Number / Specifi-
cation
(a)(f)Bolt2BACB30NX10K8
(a)(d)(f)Bolt2BACB30NX10K8X
(a)(f)Bolt2BACB30NX10K8Y
(a)(f)Bolt2BACB30NX12K8
(a)(f)Bolt26BACB30NX8K8
(a)(d)(f)Bolt26BACB30NX8K8X
(a)(f)Bolt26BACB30NX8K8Y
(a)(f)Bolt26BACB30NX10K8
(a)Collar28BACC30BH10
(a)Collar26BACC30AC8
(a)Collar26BACC30BH8
(a)Collar2BACC30AC10
(a)Collar2BACC30BH12
(b)(c)Corrosion Resistant Finish1 PtBMS10-20, TYPE II
(b)Sealant1 QtBMS5-45
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Group 2, Configuration 1, 3, 5:
NotesNameQTYPart Number / Specifi-
cation
(d)(e)Retainer Washer215-5PH
(d)(e)Retainer Washer217-7PH
(a) Refer to 737 Structural Repair Manual Chapter 51 for alternate fasteners.
(b) Refer to the Qualified Products List at the end of the Boeing Material Specification (BMS) for
supplier data.
(c) Some types of corrosion resistant finish contain Pentazinc Chromate Octahydroxide and will
not be available in the European Union (EU) after January 2019 without an authorization. EU
operators are encouraged to make sure their suppliers are authorized to provide the material
after January 2019 and that users of this material comply with the risk mitigation measures
and operational conditions.
(d) This part is only necessary for a freeze plug repair in accordance with FIGURE 7 or FIGURE
8.
(e) Fabricate from 0.125 inch thick 15-5PH or 17-7PH CRES in accordance with FIGURE 7 or
FIGURE 8.
(f) The quantities of fasteners are the maximum amount that are necessary.
Group 2, Configuration 2, 4, 6:
NotesNameQTYPart Number / Specifi-
cation
(a)(c)Bolt2BACB30NX10K8
(a)(c)Bolt2BACB30NX10K8X
(a)(c)Bolt2BACB30NX10K8Y
(a)(c)Bolt2BACB30NX12K8
(a)(c)Bolt26BACB30NX8K8
(a)(c)Bolt26BACB30NX8K8X
(a)(c)Bolt26BACB30NX8K8Y
(a)(c)Bolt26BACB30NX10K8
(a)Collar28BACC30BH10
(a)Collar26BACC30BH8
(a)Collar26BACC30AC8
(a)Collar2BACC30AC10
(a)Collar2BACC30BH12
(b)Sealant1 QtBMS5-45
(a) Refer to 737 Structural Repair Manual Chapter 51 for alternate fasteners.
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Group 2, Configuration 2, 4, 6:
NotesNameQTYPart Number / Specifi-
cation
(b) Refer to the Qualified Products List at the end of the Boeing Material Specification (BMS) for
supplier data.
(c) The quantities of fasteners are the maximum amount that are necessary.
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. Unless shown differently, these dimensions and tolerances are used:
– Linear dimensions are in inches
– Tolerance on linear dimensions, other than rivet and bolt edge margins, is plus
or minus 0.03 inch
– Tolerance on rivet and bolt edge margin is plus or minus 0.05 inch
– Angular tolerance is plus or minus 2 degrees
– Hole dimensions for standard solid rivets and fasteners are in Structural Repair
Manual (SRM) Chapter 51
– Torque Values:
— Values for structural fasteners are given in 737 Structural Repair Manual,
Chapter 51.
— Values for airframe maintenance tasks are included in Chapter 20 of 737
Aircraft Maintenance Manual (AMM).
— Values for electrical maintenance tasks are included in Chapter 20 of
Standard Wiring Practices Manual (SWPM).
— Values for engine maintenance tasks are included in Chapter 70 of 737
Aircraft Maintenance Manual (AMM).
— Non-standard torque values for maintenance tasks are included in the
applicable installation step.
4. Use the approved fastener, process and material substitutions in accordance with
SRM Chapter 51.
5. If the length of any fastener specified in this service bulletin does not meet installation
standards given in SRM Chapter 51, then a fastener of the same specification, or
an approved substitute, with a length which meets the installation standards given
in SRM Chapter 51 may be used. In addition, washers may be installed for fastener
grip length in accordance with SRM Chapter 51. Refer to SOPM 20-50-01 for alternate
full threaded fasteners (screws) needed for installation in this service bulletin.
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.
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7. Boeing Service Letter 737-SL-51-042, Damage Reporting and Repair Plan/Design
Guidelines, is an acceptable procedure to request information from Boeing for
additional structural repair instructions. The Service Letter describes what information
must be provided to Boeing before a structural repair can be provided.
8. Refer to Appendix APPENDIX A, APPENDIX B, APPENDIX C, APPENDIX D,
APPENDIX E and APPENDIX F for logic diagrams. Logic diagrams are provided as
an aid only. Information contained in Paragraph 1.E., Compliance is the primary
source for compliance times. Information in Paragraph 3.B., Work Instructions is the
primary source for tasks required for compliance.
9. 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.
10. Use of colors in Figures is based on guidance from the ATA e-Business Program
(ATA) iSpec 2200.
11. When more than one OPTION is given for a CONDITION, do only one of the OPTION
numbers. When more than one ACTION is given for a CONDITION number or an
OPTION number, do all of the ACTION numbers for that CONDITION number or
OPTION number.
12. The compliance times for the actions in Paragraph 3.B., WORK INSTRUCTIONS
are in Paragraph 1.E., Compliance.
13. 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.
B. WORK INSTRUCTIONS
Group 1:
1. Boeing endorses the FAA rules related to Limit of Validity (LOV) and recommends immediate and
permanent removal from service of any airplanes upon reaching the LOV, whether or not it is
operated under FAA jurisdiction. As such, Boeing no longer provides maintenance instructions for
airplanes that have accumulated flight cycles beyond the LOV. Airplanes in Group 1 (line numbers
1-291) have accumulated flight cycles beyond the LOV of the maintenance program. 14 CFR
121.1115 and 129.115 prohibit operation of an airplane beyond its LOV.
Group 2:
1. Do PART 1: OPEN ACCESS.
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2. Group 2, Configuration 1, 3, 5:
RC - Do PART 2: OPEN HOLE HFEC INSPECTION OF THE MLG BEAM FORWARD SUPPORT
FITTING AT FASTENER HOLES WITHOUT A FREEZE PLUG INSTALLED for any crack.
a. CONDITION 1: ANY CRACK FOUND AT ONE FASTENER HOLE IN THE INSPECTION
AREA
(1) Do PART 4: CRACK REMOVAL AND OPEN HOLE HFEC INSPECTION OF THE MLG
BEAM FORWARD SUPPORT FITTING for any crack.
(a) CONDITION 1.1: ANY REMAINING CRACK FOUND AFTER THE HOLE DIAMETER
WAS INCREASED TO THE MAXIMUM
1) Contact The Boeing Company for repair instructions and do the repair.
(b) CONDITION 1.2: NO REMAINING CRACK FOUND
1) Do PART 5: FREEZE PLUG REPAIR.
NOTE: After accomplishment of PART 5: FREEZE PLUG REPAIR the airplane
will be in a new configuration. Refer to the group-configuration table in
Paragraph 1.A., Effectivity for the applicable configuration.
b. CONDITION 2: ANY CRACK FOUND AT MORE THAN ONE FASTENER HOLE IN THE
INSPECTION AREA
(1) Contact The Boeing Company for repair instructions and do the repair.
c. CONDITION 3: NO CRACK FOUND
(1) Repeat PART 2: OPEN HOLE HFEC INSPECTION OF THE MLG BEAM FORWARD
SUPPORT FITTING AT FASTENER HOLES WITHOUT A FREEZE PLUG INSTALLED
for any crack at the times specified in Paragraph 1.E., Compliance.
3. Group 2, Configuration 2, 4, 6:
RC - For airplanes with existing freeze plug in the inspection area that was not installed in
accordance with PART 5, do the actions that follow:
a. ACTION 1: Do PART 2: OPEN HOLE HFEC INSPECTION OF THE MLG BEAM FORWARD
SUPPORT FITTING AT FASTENER HOLES WITHOUT A FREEZE PLUG INSTALLED for
any crack.
(1) CONDITION 4: ANY CRACK FOUND DURING PART 2 INSPECTION
(a) Contact The Boeing Company for repair instructions and do the repair.
(2) CONDITION 5: NO CRACK FOUND DURING PART 2 INSPECTION
(a) Repeat PART 2: OPEN HOLE HFEC INSPECTION OF THE MLG BEAM FORWARD
SUPPORT FITTING AT FASTENER HOLES WITHOUT A FREEZE PLUG
INSTALLED for any crack.
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b. ACTION 2: Do PART 3: SURFACE HFEC INSPECTION OF THE MLG BEAM FORWARD
SUPPORT FITTING AT FASTENER HOLE WITH A FREEZE PLUG INSTALLED for any
crack.
NOTE: This inspection does not supersede any existing 8100-9 inspection requirements on
the freeze plug repair.
(1) CONDITION 6: ANY CRACK FOUND DURING PART 3 INSPECTION
(a) Contact The Boeing Company for repair instructions and do the repair.
(2) CONDITION 7: NO CRACK FOUND DURING PART 3 INSPECTION
(a) Repeat PART 3: SURFACE HFEC INSPECTION OF THE MLG BEAM FORWARD
SUPPORT FITTING AT FASTENER HOLE WITH A FREEZE PLUG INSTALLED
for any crack.
4. Group 2, Configuration 2, 4, 6:
RC - For airplanes with freeze plug installed in accordance with PART 5, do the actions that follow:
a. ACTION 1: Repeat PART 2: OPEN HOLE HFEC INSPECTION OF THE MLG BEAM
FORWARD SUPPORT FITTING AT FASTENER HOLES WITHOUT A FREEZE PLUG
INSTALLED for any crack.
(1) CONDITION 4: ANY CRACK FOUND DURING PART 2 INSPECTION
(a) Contact The Boeing Company for repair instructions and do the repair.
(2) CONDITION 5: NO CRACK FOUND DURING PART 2 INSPECTION
(a) Repeat PART 2: OPEN HOLE HFEC INSPECTION OF THE MLG BEAM FORWARD
SUPPORT FITTING AT FASTENER HOLES WITHOUT A FREEZE PLUG
INSTALLED for any crack.
b. ACTION 2: Do PART 3: SURFACE HFEC INSPECTION OF THE MLG BEAM FORWARD
SUPPORT FITTING AT FASTENER HOLE WITH A FREEZE PLUG INSTALLED for any
crack.
(1) CONDITION 6: ANY CRACK FOUND DURING PART 3 INSPECTION
(a) Contact The Boeing Company for repair instructions and do the repair.
(2) CONDITION 7: NO CRACK FOUND DURING PART 3 INSPECTION
(a) Repeat PART 3: SURFACE HFEC INSPECTION OF THE MLG BEAM FORWARD
SUPPORT FITTING AT FASTENER HOLE WITH A FREEZE PLUG INSTALLED
for any crack.
5. Do PART 6: CLOSE ACCESS.
6. Put the airplane back to a serviceable condition.
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Group 2:
PART 1: OPEN ACCESS
1. Install ground lock assembly in the nose landing gear and in the left and right main landing gear
(MLG). Refer to 737-100/200 AMM 32-00-01 or 737-300/400/500 AMM 32-00-01 as an accepted
procedure.
2. Deactivate the trailing edge flap system. Refer to 737-100/200 AMM 27-51-00 or 737-300/400/500
AMM 27-51-00 as an accepted procedure.
3. Defuel the No.1 and No.2 fuel tanks. Refer to 737-100/200 AMM 28-23-00 or 737-300/400/500
AMM 28-23-00 as an accepted procedure.
4. Purge the No.1 and No.2 fuel tanks. Refer to 737-100/200 AMM 28-10-00 or 737-300/400/500
AMM 28-10-00 as an accepted procedure.
5. Install the flight control lock assembly to prevent operation of the aileron and aileron trim control
system. Refer to 737-100/200 AMM 27-11-00 or 737-300/400/500 AMM 27-11-00 as an accepted
procedure.
6. Open the No.1 and No. 2 access panels. Refer to 737-100/200 AMM 28-11-00 or 737-300/400/500
AMM 28-11-00 as an accepted procedure.
7. Remove the main landing gear support beam. Refer to 737-100/200 AMM 57-15-00 and
737-300/400/500 AMM 57-15-00 as an accepted procedure.
8. Remove fasteners at fastener holes without freeze plug in accordance with the figures below:
Right WingLeft Wing
FIGURE 2FIGURE 1
Group 2:
PART 2: OPEN HOLE HFEC INSPECTION OF THE MLG BEAM FORWARD SUPPORT FITTING
AT FASTENER HOLES WITHOUT A FREEZE PLUG INSTALLED
1. Do an open hole High Frequency Eddy Current (HFEC) inspection of the MLG beam forward
support fitting for any crack in accordance with the figures below:
Right WingLeft Wing
FIGURE 4FIGURE 3
Group 2, Configuration 2, 4, 6:
PART 3: SURFACE HFEC INSPECTION OF THE MLG BEAM FORWARD SUPPORT FITTING AT
FASTENER HOLE WITH A FREEZE PLUG INSTALLED
1. Do a surface HFEC inspection of the MLG beam forward support fitting, around the fastener, for
any crack in accordance with the figures below:
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Right WingLeft Wing
FIGURE 6FIGURE 5
Group 2, Configuration 1, 3, 5:
PART 4: CRACK REMOVAL AND OPEN HOLE HFEC INSPECTION OF THE MLG BEAM FORWARD
SUPPORT FITTING
1. Increase the diameter of the hole in the MLG beam forward support fitting in increments of 1/64
inch. The maximum hole diameter is specified in Table 1 below. Keep a minimum 2D edge margin.
Table 1: Hole Diameter Limits for Crack Removal
Maximum Hole DiameterInitial Hole Diameter
0.4500.247-0.250
0.5130.303-0.313
2. After each increment, do an open hole HFEC inspection of the MLG beam forward support fitting
for any remaining crack in accordance with 737 NDT Manual Part 6, 51-00-00, Procedure 1, 11,
or 16.
Group 2, Configuration 1, 3, 5:
PART 5: FREEZE PLUG REPAIR
1. Increase the diameter of the hole in the MLG beam forward support fitting by 1/16 inch. Keep a
minimum 2D edge margin.
2. Do a freeze plug repair in accordance with the figures below:
Right WingLeft Wing
FIGURE 8FIGURE 7
Group 2:
PART 6: CLOSE ACCESS
1. Install fasteners at fastener holes without freeze plug in accordance with the figures below:
Right WingLeft Wing
FIGURE 10FIGURE 9
2. Install the main landing gear support beam. Refer to 737-100/200 AMM 57-15-00 and
737-300/400/500 AMM 57-15-00 as an accepted procedure.
3. Close the No.1 and No. 2 access panels. Refer to 737-100/200 AMM 28-11-00 or 737-300/400/500
AMM 28-11-00 as an accepted procedure.
4. Remove the flight control lock assembly. Refer to 737-100/200 AMM 27-11-00 or 737-300/400/500
AMM 27-11-00 as an accepted procedure.
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5. Reactivate the trailing edge flap system. Refer to 737-100/200 AMM 27-51-00 or 737-300/400/500
AMM 27-51-00 as an accepted procedure.
6. Remove the ground lock assembly from the nose landing gear and the left and right MLG. Refer
to 737-100/200 AMM 32-00-01 or 737-300/400/500 AMM 32-00-01 as an accepted procedure.
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BOEING SERVICE BULLETIN 737-57A1334
ALERT  ALERT
This Figure applies only to: Group 2.
NBI
57.00
2576153
FIGURE 1: LEFT WING - MAIN LANDING GEAR BEAM FORWARD SUPPORT FITTING - REMOVAL OF
FASTENERS
(SHEET 1 OF 3)
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### Page 49 (OCR)

BOEING SERVICE BULLETIN 737-57A1334
ALERT  ALERT
14 LOCATIONS
STIFFENER  UPPER SKIN
REAR
SPAR
WEB.
FORWARD  LOWER SKIN
SUPPORT FITTING
INBD
FORWARD SUPPORT FITTING
(VIEW LOOKING AFT)
/ SEALANT  REFERENCE FASTENER  A-A  2576400
FIGURE 1: LEFT WING - MAIN LANDING GEAR BEAM FORWARD SUPPORT FITTING - REMOVAL OF
FASTENERS
(SHEET 2 OF 3)
Original Issue: September 26, 2017
Export Controlled ECCN: 9E991 - BOEING  737-57A1334
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.  49 of 101

### Page 50

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for this figure.
More DataQtyIdentificationNameTaskStep
(a)--SealantRemove1
(b)14-FastenerRemove2
(a) Refer to 737-100/200 AMM 51-31-00 or 737-300/400/500 AMM 51-31-00 as an accepted procedure.
(b) Remove fasteners at fastener holes without a freeze plug repair installed.
FIGURE 1: LEFT WING - MAIN LANDING GEAR BEAM FORWARD SUPPORT FITTING - REMOVAL OF
FASTENERS
(SHEET 3 OF 3)
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: September 26, 2017
737-57A1334
50 of 101
BOEING SERVICE BULLETIN 737-57A1334
ALERTALERT

### Page 51 (OCR)

BOEING SERVICE BULLETIN 737-57A1334
ALERT  ALERT
This Figure applies only to: Group 2.
WBL
135.50
WBL
157.00
2576484
FIGURE 2: RIGHT WING - MAIN LANDING GEAR BEAM FORWARD SUPPORT FITTING - REMOVAL OF
FASTENERS
(SHEET 1 OF 3)
Original Issue: September 26, 2017
Export Controlled ECCN: 9E991 - BOEING  737-57A1334
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.  51 of 101

### Page 52 (OCR)

BOEING SERVICE BULLETIN 737-57A1334
ALERT  ALERT
14 LOCATIONS
UPPER SKIN  STIFFENER
REAR
SPAR
WEB
LOWER SKIN  FORWARD
SUPPORT FITTING
INBD
FORWARD SUPPORT FITTING
(VIEW LOOKING AFT)
REFERENCE FASTENER
SEALANT  A-A  2576492
FIGURE 2: RIGHT WING - MAIN LANDING GEAR BEAM FORWARD SUPPORT FITTING - REMOVAL OF
FASTENERS
(SHEET 2 OF 3)
Original Issue: September 26, 2017
PROPRIETARY - Copyright © Unpublished  Export Controlled ECCN: 9E991 - BOEING  737-57A1334
Work - See page 1 for details.  52 of 101

### Page 53

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for this figure.
More DataQtyIdentificationNameTaskStep
(a)--SealantRemove1
(b)14-FastenerRemove2
(a) Refer to 737-100/200 AMM 51-31-00 or 737-300/400/500 AMM 51-31-00 as an accepted procedure.
(b) Remove fasteners at fastener holes without a freeze plug repair installed.
FIGURE 2: RIGHT WING - MAIN LANDING GEAR BEAM FORWARD SUPPORT FITTING - REMOVAL OF
FASTENERS
(SHEET 3 OF 3)
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: September 26, 2017
737-57A1334
53 of 101
BOEING SERVICE BULLETIN 737-57A1334
ALERTALERT

### Page 54 (OCR)

BOEING SERVICE BULLETIN 737-57A1334
ALERT  ALERT
This Figure applies only to: Group 2.
NBI
57.00
2576670
FIGURE 3: LEFT WING - MAIN LANDING GEAR BEAM FORWARD SUPPORT FITTING - OPEN HOLE HFEC
INSPECTION
(SHEET 1 OF 3)
Original Issue: September 26, 2017
PROPRIETARY - Copyright © Unpublished  Export Controlled ECCN: 9E991 - BOEING  737-57A1334
Work - See page 1 for details.  54 of 101

### Page 55 (OCR)

BOEING SERVICE BULLETIN 737-57A1334
ALERT  ALERT
14 LOCATIONS
STIFFENER  •  UPPER SKIN
REAR
SPAR
WEB
FORWARD  LOWER SKIN
SUPPORT FITTING
INBD
FORWARD SUPPORT FITTING
(VIEW LOOKING AFT)
A-A
REFERENCE FASTENER
2576671
FIGURE 3: LEFT WING - MAIN LANDING GEAR BEAM FORWARD SUPPORT FITTING - OPEN HOLE HFEC
INSPECTION
(SHEET 2 OF 3)
Original Issue: September 26, 2017
Export Controlled ECCN: 9E991 - BOEING  737-57A1334
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.  55 of 101

### Page 56

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for this figure.
More DataQtyIdentificationNameTaskStep
(a)(b)14-Fastener HoleInspect1
(a) Do an open hole HFEC inspection of the MLG beam forward support fitting for any crack in accordance
with 737 NDT Manual Part 6, 51-00-00, Procedure 1, 11, or 16.
(b) It is not necessary to do the open hole HFEC inspection at any fastener hole with a freeze plug installed.
FIGURE 3: LEFT WING - MAIN LANDING GEAR BEAM FORWARD SUPPORT FITTING - OPEN HOLE HFEC
INSPECTION
(SHEET 3 OF 3)
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: September 26, 2017
737-57A1334
56 of 101
BOEING SERVICE BULLETIN 737-57A1334
ALERTALERT

### Page 57 (OCR)

BOEING SERVICE BULLETIN 737-57A1334
ALERT  ALERT
This Figure applies only to: Group 2.
WBL
135.50
WBL
157.00
2576673
FIGURE 4: RIGHT WING - MAIN LANDING GEAR BEAM FORWARD SUPPORT FITTING - OPEN HOLE
HFEC INSPECTION
(SHEET 1 OF 3)
Original Issue: September 26, 2017
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.  57 of 101

### Page 58 (OCR)

BOEING SERVICE BULLETIN 737-57A1334
ALERT  ALERT
14 LOCATIONS
UPPER SKIN  STIFFENER
REAR
SPAR
WEB
LOWER SKIN  FORWARD
SUPPORT FITTING
INBD
FORWARD SUPPORT FITTING
(VIEW LOOKING AFT)
A-A
REFERENCE FASTENER
2576674
FIGURE 4: RIGHT WING - MAIN LANDING GEAR BEAM FORWARD SUPPORT FITTING - OPEN HOLE
HFEC INSPECTION
(SHEET 2 OF 3)
Original Issue: September 26, 2017
PROPRIETARY - Copyright © Unpublished  Export Controlled ECCN: 9E991 - BOEING  737-57A1334
Work - See page 1 for details.  58 of 101

### Page 59

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for this figure.
More DataQtyIdentificationNameTaskStep
(a)(b)14-Fastener HoleInspect1
(a) Do an open hole HFEC inspection of the MLG beam forward support fitting for any crack in accordance
with 737 NDT Manual Part 6, 51-00-00, Procedure 1, 11, or 16.
(b) It is not necessary to do the open hole HFEC inspection at any fastener hole with a freeze plug installed.
FIGURE 4: RIGHT WING - MAIN LANDING GEAR BEAM FORWARD SUPPORT FITTING - OPEN HOLE
HFEC INSPECTION
(SHEET 3 OF 3)
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: September 26, 2017
737-57A1334
59 of 101
BOEING SERVICE BULLETIN 737-57A1334
ALERTALERT

### Page 60 (OCR)

BOEING SERVICE BULLETIN 737-57A1334
ALERT  ALERT
This Figure applies only to: Group 2, Configuration 2, 4, 6.
NBI
57.00
2576677
FIGURE 5: LEFT WING - MAIN LANDING GEAR BEAM FORWARD SUPPORT FITTING - SURFACE HFEC
INSPECTION AT EACH FASTENER HOLE WITH FREEZE PLUG
(SHEET 1 OF 3)
Original Issue: September 26, 2017
Export Controlled ECCN: 9E991 - BOEING  PROPRIETARY - Copyright © Unpublished  737-57A1334
Work - See page 1 for details.  60 of 101

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