# Boeing Alert Service Bulletin 737-57A1345: No revision named

- Rights: © The Boeing Company. Filed by the FAA in regulations.gov docket FAA-2020-0097, the docket of AD 2020-14-03. Not covered by OpenAirDocs’ CC0 dedication.
- Document: [Boeing Alert Service Bulletin 737-57A1345](https://openairdocs.org/service-documents/boeing/737-57a1345.md)
- Title as filed: 737-57A1345-00--RB
- Pages: 29
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## Text

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### Page 1

Commercial 
Airplanes
737
Requirements Bulletin
ALERT
Number: 737-57A1345 RB
Original Issue: December 17, 2019
ATA System: 5720
SUBJECT: WINGS - Front Spar - Inspection of Nacelle Support Overwing Fitting at WBL 191
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:
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Unpublished Work.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: December 17, 2019
737-57A1345 RB
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2.0

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Table of Contents
1. EFFECTIVITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
A. Airplanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
B. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2. CONCURRENT REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3. COMPLIANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4. APPROVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
A. General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
B. Work Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
FIGURE 2: ULTRASONIC INSPECTION OF NACELLE SUPPORT OVERWING FITTING - LEFT . . 22
FIGURE 3: GENERAL VISUAL INSPECTION OF THE STRUT TO WING - DIAGONAL BRACE - LEFT
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
FIGURE 5: ULTRASONIC INSPECTION OF NACELLE SUPPORT OVERWING FITTING - RIGHT . 26
FIGURE 6: GENERAL VISUAL INSPECTION OF THE STRUT TO WING - DIAGONAL BRACE - RIGHT
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
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Commercial 
Airplanes
737
Requirements Bulletin
ALERT
Number: 737-57A1345 RB
Original Issue: December 17, 2019
ATA System: 5720
SUBJECT: WINGS - Front Spar - Inspection of Nacelle Support Overwing Fitting at WBL 191
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. THIS IS AN ENHANCED REQUIRED FOR COMPLIANCE DOCUMENT. THE BOEING
PROCESSES USED TO CREATE THE SERVICE BULLETIN (SB) AND THE REQUIREMENTS BULLETIN
(RB) ENSURE THAT THE INFORMATION BETWEEN "RC START" AND "RC END" IN THE SB ARE IDENTICAL
TO THE INFORMATION IN THE SAME SECTIONS (COMPLIANCE, WORK INSTRUCTIONS…) OF THE RB
WHICH THE SB REFERS TO AS THE RELATED DOCUMENT.
1. Effectivity
A. Airplanes
This bulletin is applicable to 737-300, 737-400, 737-500 Airplane(s), line number(s) 1001, 1007,
1015, 1022, 1030, 1037, 1043, 1048, 1052, 1057, 1063, 1069, 1073, 1076, 1080, 1083, 1087,
1090, 1092, 1094, 1096, 1098, 1100-1101, 1103-1104, 1106-1108, 1110-1112, 1114-1116,
1118-1119, 1121-1134, 1136-1142, 1144-1150, 1152-1153, 1156-1164, 1166, 1168-1175, 1177,
1179-1185, 1187-1188, 1190-1193, 1195-1196, 1198, 1200-1202, 1204-1222, 1224-1225,
1227-1235, 1237-1240, 1242-1244, 1246-1255, 1258-1260, 1263-1264, 1268-1298, 1300-1312,
1314-1318, 1320-1328, 1330-1341, 1343-1346, 1348-1360, 1362-1368, 1370, 1372-1378,
1380-1386, 1388-1391, 1393-1396, 1398, 1400, 1402, 1404, 1406-1413, 1416-1417, 1419, 1421,
1423, 1425, 1427-1452, 1454-1455, 1457-1485, 1487-1522, 1524-1529, 1531-1564, 1566-1578,
1580, 1582, 1584, 1586-3132 in 3 Group(s). Where the effectivity is presented with hyphens
between line numbers, the airplane applicability means "through" and "inclusive", e.g. line numbers
1-9 means line numbers 1 through 9 inclusive.
DESCRIPTIONCONFIGURATIONGROUP
737-300 airplanes with Titanium, Non Shot Peened, Nacelle Support
Overwing Fittings.
-1
737-300/-400/-500 Airplanes with Titanium Shot Peened Nacelle
Support Overwing Fittings.
-2
737-300/-400/-500 Airplanes with a Steel Nacelle Support Overwing
Fitting or a Titanium Shot Peened Nacelle Support Overwing Fitting.
-3
Airplane Models:
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737-300, 737-400, 737-500
GroupVariable Number
2PJ301 - PJ302
2PJ551 - PJ560
3PJ561
2PJ601 - PJ615
3PJ811
2PJ816 - PJ817
2PM381 - PM399
2PM401 - PM417
2PM541 - PM564
1PP001 - PP026
2PP027 - PP054
1PP101 - PP125
2PP126 - PP160
1PP161 - PP168
2PP169
1PP181 - PP182
2PP183 - PP199
1PP201 - PP204
2PP205
1PP221
1PP231 - PP243
1PP281 - PP286
1PP301 - PP305
1PP351 - PP352
2PP353
1PP376 - PP384
2PP391 - PP393
1PP401 - PP420
2PP421 - PP440
1PP471 - PP475
1PP501 - PP504
GroupVariable Number
2PP505 - PP520
1PP521 - PP522
1PP631 - PP634
1PP651 - PP652
1PP671 - PP699
1PP701 - PP718
2PP719 - PP733
1PP771 - PP777
2PP778 - PP779
1PP801 - PP804
2PP805 - PP808
1PP821 - PP827
1PP831 - PP835
2PP836 - PP845
1PP846 - PP847
2PP848
1PP851
2PP852
1PP861 - PP870
2PP871 - PP877
1PP891 - PP898
2PP899
2PP901 - PP930
1PP931 - PP934
2PP935 - PP936
1PP946 - PP947
2PP948
2PP951 - PP952
2PP961 - PP967
2PP981 - PP991
2PP993
GroupVariable Number
1PQ001 - PQ012
2PQ013 - PQ016
1PQ026 - PQ037
2PQ038 - PQ041
1PQ051 - PQ060
2PQ061 - PQ092
1PQ101 - PQ110
2PQ111 - 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
3PQ451
2PQ454
2PQ471 - PQ475
2PQ479 - PQ481
2PQ486 - PQ487
2PQ491 - PQ493
2PQ771 - PQ772
2PQ791 - PQ793
2PQ801 - PQ805
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GroupVariable Number
2PQ931 - PQ935
2PQ951
2PQ971 - PQ974
3PQ975 - PQ976
2PQ977 - PQ997
2PR001 - PR002
3PR003 - PR004
2PR005 - PR017
2PR021 - PR031
3PR032
2PR033 - PR034
3PR041 - PR042
2PR043 - 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
GroupVariable Number
2PS841 - PS846
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
GroupVariable Number
2PT701 - PT703
2PT716 - PT717
2PT721 - PT725
2PT801 - PT834
2PT851 - PT854
2PT871 - PT886
2PT901 - PT930
2PT971 - PT973
2PT981 - PT982
3PT983
2PT984 - 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
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GroupVariable Number
2PW156 - PW157
2PW161 - PW171
2PW201 - PW252
2PW261 - PW268
2PW271 - PW276
2PW278
2PW281 - PW293
2PW296
2PW301 - PW327
2PW401 - PW408
2PW411 - PW418
GroupVariable Number
2PW421 - PW424
2PW431 - PW435
2PW441 - PW450
2PW461 - PW467
2PW501 - PW504
2PW511 - PW522
2PW524 - PW550
2PW556 - PW557
2PW561 - PW564
2PW571 - PW576
2PW591 - PW596
GroupVariable Number
2PW611 - PW622
2PW631 - PW637
2PW661 - PW662
2PW681 - PW683
2PW701 - PW702
2PW711 - PW717
2PW741 - PW742
2PW761
2PW771
3PW831
2PW851 - PW856
B. Spares Affected
None.
2. CONCURRENT REQUIREMENTS
None.
3. COMPLIANCE
The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to
Requirements Bulletin 737-57A1345 RB. The Airworthiness Directive will make the compliance tasks and
times given in this service bulletin mandatory.
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 or an OPTION, do all of the ACTION numbers for that
CONDITION or OPTION.
Group 1:
Table 1: Ultrasonic Inspection of the Nacelle Support Overwing Fitting - Airplanes with Titanium Non
Shot Peened Fitting - Left
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
-Within 4,500 Flight Cycles after
the original issue date of Require-
ments Bulletin (RB) 737-57A1345
RB.
Do an ultrasonic inspec-
tion of the Nacelle Sup-
port Overwing Fitting at
WBL 191 for any crack.
All Airplanes
-Before further flight.Contact The Boeing
Company for repair in-
structions and do the re-
pair.
CONDITION 1: ANY
CRACK FOUND
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Group 1:
Table 1: Ultrasonic Inspection of the Nacelle Support Overwing Fitting - Airplanes with Titanium Non
Shot Peened Fitting - Left
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
4,500 Flight Cy-
cles.
-Repeat ultrasonic inspec-
tion of the Nacelle Sup-
port Overwing Fitting at
WBL 191 for any crack.
(a)
CONDITION 2: NO
CRACK FOUND
(a) Replacement with a steel nacelle support overwing fitting is terminating action to the repeat inspection.
Group 1:
Table 2: Ultrasonic Inspection of the Nacelle Support Overwing Fitting - Airplanes with Titanium Non
Shot Peened Fitting - Right
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
-Within 4,500 Flight Cycles after
the original issue date of Require-
ments Bulletin (RB) 737-57A1345
RB.
Do an ultrasonic inspec-
tion of the Nacelle Sup-
port Overwing Fitting at
WBL 191 for any crack.
All Airplanes
-Before further flight.Contact The Boeing
Company for repair in-
structions and do the re-
pair.
CONDITION 3: ANY
CRACK FOUND
4,500 Flight Cy-
cles.
-Repeat ultrasonic inspec-
tion of the Nacelle Sup-
port Overwing Fitting at
WBL 191 for any crack.
(a)
CONDITION 4: NO
CRACK FOUND
(a) Replacement with a steel nacelle support overwing fitting is terminating action to the repeat inspection.
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### Page 10

Group 2:
Table 3: Ultrasonic Inspection of the Nacelle Support Overwing Fitting - Airplanes with a Titanium Shot
Peened Fitting - Left
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
-Within 4,500
Flight Cycles af-
ter the original
issue date of
Requirements
Bulletin (RB)
737-57A1345
RB.
Before 44,000
total Flight Cy-
cles.
Do an ultrasonic inspec-
tion of the Nacelle Sup-
port Overwing Fitting at
WBL 191 for any crack.
All Airplanes
-Before further flight.Contact The Boeing
Company for repair in-
structions and do the re-
pair.
CONDITION 5: ANY
CRACK FOUND
4,500 Flight Cy-
cles.
-Repeat ultrasonic inspec-
tion of the Nacelle Sup-
port Overwing Fitting at
WBL 191 for any crack.
(a)
CONDITION 6: NO
CRACK FOUND
(a) Replacement with a steel nacelle support overwing fitting is terminating action to the repeat inspection.
Group 2:
Table 4: Ultrasonic Inspection of the Nacelle Support Overwing Fitting - Airplanes with a Titanium Shot
Peened Fitting - Right
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
-Within 4,500
Flight Cycles af-
ter the original
issue date of
Requirements
Bulletin (RB)
737-57A1345
RB.
Before 44,000
total Flight Cy-
cles.
Do an ultrasonic inspec-
tion of the Nacelle Sup-
port Overwing Fitting at
WBL 191 for any crack.
All Airplanes
-Before further flight.Contact The Boeing
Company for repair in-
structions and do the re-
pair.
CONDITION 7: ANY
CRACK FOUND
4,500 Flight Cy-
cles.
-Repeat ultrasonic inspec-
tion of the Nacelle Sup-
port Overwing Fitting at
WBL 191 for any crack.
(a)
CONDITION 8: NO
CRACK FOUND
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Group 2:
Table 4: Ultrasonic Inspection of the Nacelle Support Overwing Fitting - Airplanes with a Titanium Shot
Peened Fitting - Right
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
(a) Replacement with a steel nacelle support overwing fitting is terminating action to the repeat inspection.
Group 3:
Table 5: Magnetic Check and Ultrasonic Inspection of the Nacelle Support Overwing Fitting - Airplanes
with a Steel or a Titanium Shot Peened Nacelle Support Overwing Fitting - Left
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
-Within 4,500
Flight Cycles af-
ter the original
issue date of
Requirements
Bulletin (RB)
737-57A1345
RB.
Before 44,000
total Flight Cy-
cles.
Do a magnetic check to
determine the material of
the Nacelle Support
Overwing Fitting at WBL
191.
All Airplanes
--No further action is re-
quired.
CONDITION 9: NACELLE
SUPPORT OVERWING
FITTING IS STEEL
-Before further flight.Do an ultrasonic inspec-
tion of the Nacelle Sup-
port Overwing Fitting at
WBL 191 for any crack.
CONDITION 10: NACELLE
SUPPORT OVERWING
FITTING IS TITANIUM
-Before further flight.Contact The Boeing
Company for repair in-
structions and do the re-
pair.
CONDITION 10.1: ANY
CRACK FOUND
4,500 Flight Cy-
cles.
-Repeat ultrasonic inspec-
tion of the Nacelle Sup-
port Overwing Fitting at
WBL 191 for any crack.
(a)
CONDITION 10.2: NO
CRACK FOUND
(a) Replacement with a steel nacelle support overwing fitting is terminating action to the repeat inspection.
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### Page 12

Group 3:
Table 6: Magnetic Check and Ultrasonic Inspection of the Nacelle Support Overwing Fitting - Airplanes
with a Steel or a Titanium Shot Peened Nacelle Support Overwing Fitting - Right
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
-Within 4,500
Flight Cycles af-
ter the original
issue date of
Requirements
Bulletin (RB)
737-57A1345
RB.
Before 44,000
total Flight Cy-
cles.
Do a magnetic check to
determine the material of
the Nacelle Support
Overwing Fitting at WBL
191.
All Airplanes
--No further action is re-
quired.
CONDITION 11: NACELLE
SUPPORT OVERWING
FITTING IS STEEL
-Before further flight.Do an ultrasonic inspec-
tion of the Nacelle Sup-
port Overwing Fitting at
WBL 191 for any crack.
CONDITION 12: NACELLE
SUPPORT OVERWING
FITTING IS TITANIUM
-Before further flight.Contact The Boeing
Company for repair in-
structions and do the re-
pair.
CONDITION 12.1: ANY
CRACK FOUND
4,500 Flight Cy-
cles.
-Repeat ultrasonic inspec-
tion of the Nacelle Sup-
port Overwing Fitting at
WBL 191 for any crack.
(a)
CONDITION 12.2: NO
CRACK FOUND
(a) Replacement with a steel nacelle support overwing fitting is terminating action to the repeat inspection.
Table 7: General Visual Inspection of the Strut to Wing - Diagonal Brace - Left
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
-Within 4,500 Flight Cycles after
the original issue date of Require-
ments Bulletin (RB) 737-57A1345
RB.
Do a general visual in-
spection of the Strut to
Wing Diagonal Brace at
nacelle STA 278 for any
crack.
All Airplanes
-Before further flight.Contact the Boeing Com-
pany for repair instruc-
tions and do the repair.
CONDITION 13: ANY
CRACK FOUND
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### Page 13

Table 7: General Visual Inspection of the Strut to Wing - Diagonal Brace - Left
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
4,500 Flight Cy-
cles.
-Repeat general visual in-
spection of the Strut to
Wing Diagonal Brace at
nacelle STA 278 for any
crack.
CONDITION 14: NO
CRACK FOUND
Table 8: General Visual Inspection of the Strut to Wing - Diagonal Brace - Right
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
-Within 4,500 Flight Cycles after
the original issue date of Require-
ments Bulletin (RB) 737-57A1345
RB.
Do a general visual in-
spection of the Strut to
Wing Diagonal Brace at
nacelle STA 278 for any
crack.
All Airplanes
-Before further flight.Contact the Boeing Com-
pany for repair instruc-
tions and do the repair.
CONDITION 15: ANY
CRACK FOUND
4,500 Flight Cy-
cles.
-Repeat general visual in-
spection of the Strut to
Wing Diagonal Brace at
nacelle STA 278 for any
crack.
CONDITION 16: NO
CRACK FOUND
4. APPROVAL
This Requirements Bulletin was examined by the Federal Aviation Administration (FAA). The changes
specified in this document 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 document and its approval were based on the airplane
in its original Boeing delivery configuration or as modified by other Boeing changes.
If an airplane has a non-Boeing modification or repair that affects a component or system also affected by
this Requirements Bulletin, the operator is responsible for obtaining appropriate regulatory agency approval
before incorporating this Requirements Bulletin.
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5.    ACCOMPLISHMENT INSTRUCTIONS
A. GENERAL INFORMATION
NOTE: 1. This is an Enhanced Required for Compliance document. There will be a separate
Service Bulletin (SB) and a separate Requirements Bulletin (RB). If an RB is mandated
by an Airworthiness Directive (AD), then all applicable requirements specified in the
RB must be done. For the related SB, some locations are marked RC Start and RC
End to identify the requirements that are restated from the RB. For the related SB,
the areas between RC Start and RC End, including sub-steps and any figures
identified between RC Start and RC End, must be done to comply with the AD.
Therefore, an Alternative Method of Compliance (AMOC) is required for any deviations
to steps between RC Start and RC End, including substeps and identified figures.
For the related SB, the steps not between RC Start and RC End 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
steps between RC Start and RC End, including sub-steps and identified figures, can
still be done as specified, and the airplane can be put back in an airworthy condition.
Figures not required for compliance are omitted from the RB.
2. This is an Enhanced Required for Compliance document. The Boeing processes
used to create the Service Bulletin (SB) and the Requirements Bulletin (RB) ensure
that the information between "RC Start" and "RC End" in the SB are identical to the
information in the same sections (Compliance, Work Instructions...) of the RB which
the SB refers to as the related document.
3. The compliance times for the actions in WORK INSTRUCTIONS are in Compliance.
4. 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.
5. 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).
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REQUIREMENTS BULLETIN 737-57A1345
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— Non-standard torque values for maintenance tasks are included in the
applicable installation step.
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.
7. Where the work instructions include installation of a kept part, a new or serviceable
part with the same part number can be installed as an alternative to the kept part.
8. 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.
9. A Detailed Inspection is defined as: An intensive examination of a specific item,
installation or assembly to detect damage, failure or irregularity. This could include
tactile assessment in which a component or assembly can be checked for
tightness/security. Available lighting is normally supplemented with a direct source
of good lighting at an intensity deemed appropriate. Inspection aids such as mirrors
and magnifying lenses may be necessary. Surface cleaning and elaborate access
procedures may be required.
10. 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 or an OPTION,
do all of the ACTION numbers for that CONDITION or OPTION.
B. WORK INSTRUCTIONS
Actions Required for Compliance
1. Requirements
Group 1:
Table 1: Ultrasonic Inspection of the Nacelle Support Overwing Fitting - Airplanes with Titanium
Non Shot Peened Fitting - Left
Refer to the listed
procedures in SB 737-
57A1345 Original Is-
sue or later approved
revisions as an ac-
cepted procedure.
Method of
Compliance
ActionCondition
PART 1: Open Access.-Do an ultrasonic inspection
of the Nacelle Support
Overwing Fitting at WBL
191 for any crack.
All Airplanes
-FIGURE 2
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### Page 17

Group 1:
Table 1: Ultrasonic Inspection of the Nacelle Support Overwing Fitting - Airplanes with Titanium
Non Shot Peened Fitting - Left
Refer to the listed
procedures in SB 737-
57A1345 Original Is-
sue or later approved
revisions as an ac-
cepted procedure.
Method of
Compliance
ActionCondition
--Contact The Boeing Com-
pany for repair instructions
and do the repair.
CONDITION 1: ANY
CRACK FOUND PART 2: Close Access.-
PART 2: Close Access.-Repeat ultrasonic inspec-
tion of the Nacelle Support
Overwing Fitting at WBL
191 for any crack. (a)
CONDITION 2: NO
CRACK FOUND PART 1: Open Access.-
-FIGURE 2
(a) Replacement with a steel nacelle support overwing fitting is terminating action to the repeat
inspection.
Group 1:
Table 2: Ultrasonic Inspection of the Nacelle Support Overwing Fitting - Airplanes with Titanium
Non Shot Peened Fitting - Right
Refer to the listed
procedures in SB 737-
57A1345 Original Is-
sue or later approved
revisions as an ac-
cepted procedure.
Method of
Compliance
ActionCondition
PART 1: Open Access.-Do an ultrasonic inspection
of the Nacelle Support
Overwing Fitting at WBL
191 for any crack.
All Airplanes
-FIGURE 5
--Contact The Boeing Com-
pany for repair instructions
and do the repair.
CONDITION 3: ANY
CRACK FOUND PART 2: Close Access.-
PART 2: Close Access.-Repeat ultrasonic inspec-
tion of the Nacelle Support
Overwing Fitting at WBL
191 for any crack. (a)
CONDITION 4: NO
CRACK FOUND PART 1: Open Access.-
-FIGURE 5
(a) Replacement with a steel nacelle support overwing fitting is terminating action to the repeat
inspection.
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### Page 18

Group 2:
Table 3: Ultrasonic Inspection of the Nacelle Support Overwing Fitting - Airplanes with Titanium
Shot Peened Fitting - Left
Refer to the listed
procedures in SB 737-
57A1345 Original Is-
sue or later approved
revisions as an ac-
cepted procedure.
Method of
Compliance
ActionCondition
PART 1: Open Access.-Do an ultrasonic inspection
of the Nacelle Support
Overwing Fitting at WBL
191 for any crack.
All Airplanes
-FIGURE 2
--Contact The Boeing Com-
pany for repair instructions
and do the repair.
CONDITION 5: ANY
CRACK FOUND PART 2: Close Access.-
PART 2: Close Access.-Repeat ultrasonic inspec-
tion of the Nacelle Support
Overwing Fitting at WBL
191 for any crack. (a)
CONDITION 6: NO
CRACK FOUND PART 1: Open Access.-
-FIGURE 2
(a) Replacement with a steel nacelle support overwing fitting is terminating action to the repeat
inspection.
Group 2:
Table 4: Ultrasonic Inspection of the Nacelle Support Overwing Fitting - Airplanes with Titanium
Shot Peened Fitting - Right
Refer to the listed
procedures in SB 737-
57A1345 Original Is-
sue or later approved
revisions as an ac-
cepted procedure.
Method of
Compliance
ActionCondition
PART 1: Open Access.-Do an ultrasonic inspection
of the Nacelle Support
Overwing Fitting at WBL
191 for any crack.
All Airplanes
-FIGURE 5
--Contact The Boeing Com-
pany for repair instructions
and do the repair.
CONDITION 7: ANY
CRACK FOUND PART 2: Close Access.-
PART 2: Close Access.-Repeat ultrasonic inspec-
tion of the Nacelle Support
Overwing Fitting at WBL
191 for any crack. (a)
CONDITION 8: NO
CRACK FOUND PART 1: Open Access.-
-FIGURE 5
(a) Replacement with a steel nacelle support overwing fitting is terminating action to the repeat
inspection.
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### Page 19

Group 3:
Table 5: Magnetic Check and Ultrasonic Inspection of the Nacelle Support Overwing Fitting - Air-
planes with a Steel or a Titanium Shot Peened Nacelle Support Overwing Fitting - Left
Refer to the listed
procedures in SB 737-
57A1345 Original Is-
sue or later approved
revisions as an ac-
cepted procedure.
Method of
Compliance
ActionCondition
PART 1: Open Access.-Do a magnetic check to
determine the material and
ultrasonic inspection of the
Nacelle Support Overwing
Fitting at WBL 191 for any
crack.
All Airplanes
FIGURE 1-
PART 2: Close Access.-No further action is re-
quired.
CONDITION 9: NACELLE
SUPPORT OVERWING
FITTING IS STEEL
-FIGURE 2Do an ultrasonic inspection
of the Nacelle Support
Overwing Fitting at WBL
191 for any crack. (a)
CONDITION 10: NACELLE
SUPPORT OVERWING
FITTING IS TITANIUM
--Contact The Boeing Com-
pany for repair instructions
and do the repair.
CONDITION 10.1: ANY
CRACK FOUND PART 2: Close Access.-
PART 2: Close Access.-Repeat ultrasonic inspec-
tion of the Nacelle Support
Overwing Fitting at WBL
191 for any crack. (a)
CONDITION 10.2: NO
CRACK FOUND PART 1: Open Access.-
-FIGURE 2
(a) Replacement with a steel nacelle support overwing fitting is terminating action to the repeat
inspection.
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### Page 20

Group 3:
Table 6: Magnetic Check and Ultrasonic Inspection of the Nacelle Support Overwing Fitting - Air-
planes with a Steel or a Titanium Shot Peened Nacelle Support Overwing Fitting - Right
Refer to the listed
procedures in SB 737-
57A1345 Original Is-
sue or later approved
revisions as an ac-
cepted procedure.
Method of
Compliance
ActionCondition
PART 1: Open Access.-Do a magnetic check to
determine the material and
ultrasonic inspection of the
Nacelle Support Overwing
Fitting at WBL 191 for any
crack.
All Airplanes
FIGURE 4-
PART 2: Close Access-No further action is re-
quired.
CONDITION 11: NACELLE
SUPPORT OVERWING
FITTING IS STEEL
-FIGURE 5Do an ultrasonic inspection
of the Nacelle Support
Overwing Fitting at WBL
191 for any crack. (a)
CONDITION 12: NACELLE
SUPPORT OVERWING
FITTING IS TITANIUM
--Contact The Boeing Com-
pany for repair instructions
and do the repair.
CONDITION 12.1: ANY
CRACK FOUND PART 2: Close Access.-
PART 2: Close Access.-Repeat ultrasonic inspec-
tion of the Nacelle Support
Overwing Fitting at WBL
191 for any crack. (a)
CONDITION 12.2: NO
CRACK FOUND PART 1: Open Access.-
-FIGURE 5
(a) Replacement with a steel nacelle support overwing fitting is terminating action to the repeat
inspection.
Table 7: General Visual Inspection of the Strut to Wing - Diagonal Brace - Left
Refer to the listed
procedures in SB 737-
57A1345 Original Is-
sue or later approved
revisions as an ac-
cepted procedure.
Method of
Compliance
ActionCondition
PART 1: Open Access.-Do a general visual inspec-
tion of the Strut to Wing Di-
agonal Brace nacelle at
STA 278 for any crack.
All Airplanes
-FIGURE 3
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### Page 21

Table 7: General Visual Inspection of the Strut to Wing - Diagonal Brace - Left
Refer to the listed
procedures in SB 737-
57A1345 Original Is-
sue or later approved
revisions as an ac-
cepted procedure.
Method of
Compliance
ActionCondition
--Contact the Boeing Compa-
ny for repair instructions
and do the repair.
CONDITION 13: ANY
CRACK FOUND PART 2: Close Access.-
PART 2: Close Access.-Repeat general visual in-
spection of the Strut to
Wing Diagonal Brace at
nacelle STA 278 for any
crack.
CONDITION 14: NO
CRACK FOUND PART 1: Open Access.-
-FIGURE 3
Table 8: General Visual Inspection of the Strut to Wing - Diagonal Brace - Right
Refer to the listed
procedures in SB 737-
57A1345 Original Is-
sue or later approved
revisions as an ac-
cepted procedure.
Method of
Compliance
ActionCondition
PART 1: Open Access.-Do a general visual inspec-
tion of the Strut to Wing Di-
agonal Brace nacelle at
STA 278 for any crack.
All Airplanes
-FIGURE 6
--Contact the Boeing Compa-
ny for repair instructions
and do the repair.
CONDITION 15: ANY
CRACK FOUND PART 2: Close Access.-
PART 2: Close Access.-Repeat general visual in-
spection of the Strut to
Wing Diagonal Brace at
nacelle STA 278 for any
crack.
CONDITION 16: NO
CRACK FOUND PART 1: Open Access.-
-FIGURE 6
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### Page 22 (OCR)

REQUIREMENTS BULLETIN 737-57A1345
ALERT  ALERT
OVERWING
FITTING
UPPER LINK
FITTING
e
FRONT SPAR
2887284
FIGURE 2: ULTRASONIC INSPECTION OF NACELLE SUPPORT OVERWING FITTING - LEFT
(SHEET 1 OF 2)
Original Issue: December 17, 2019
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Work - See page 1 for details.  22 of 29

### Page 23

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)165C25202-( )OVERWING FITTINGInspect1
(a) Do an Ultrasonic Inspection of the nacelle support overwing fitting for any crack, in accordance with 737
NDT Manual Part 4, 57-10-20.
FIGURE 2: ULTRASONIC INSPECTION OF NACELLE SUPPORT OVERWING FITTING - LEFT
(SHEET 2 OF 2)
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### Page 24 (OCR)

REQUIREMENTS BULLETIN 737-57A1345
ALERT  ALERT
UPPER LINK  WING
NACELLE STRUT
1 DIAGONA
BRACI
LEFT WING SHOWN
RIGHT WING OPPOSITE  2887348
FIGURE 3: GENERAL VISUAL INSPECTION OF THE STRUT TO WING - DIAGONAL BRACE - LEFT
(SHEET 1 OF 2)
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### Page 25

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)1311A1730-( )DIAGONAL BRACEInspect1
(a) Do a general visual inspection of the diagonal brace for any crack.
FIGURE 3: GENERAL VISUAL INSPECTION OF THE STRUT TO WING - DIAGONAL BRACE - LEFT
(SHEET 2 OF 2)
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### Page 26 (OCR)

REQUIREMENTS BULLETIN 737-57A1345
ALERT  ALERT
OVERWING
FITTING
UPPER LINK
FITTING
FRONT SPAR
2887565
FIGURE 5: ULTRASONIC INSPECTION OF NACELLE SUPPORT OVERWING FITTING - RIGHT
(SHEET 1 OF 2)
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Work - See page 1 for details.  26 of 29

### Page 27

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)165C25202-( )OVERWING FITTINGInspect1
(a) Do an Ultrasonic Inspection of the nacelle support overwing fitting for any crack, in accordance with 737
NDT Manual Part 4, 57-10-20.
FIGURE 5: ULTRASONIC INSPECTION OF NACELLE SUPPORT OVERWING FITTING - RIGHT
(SHEET 2 OF 2)
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### Page 28 (OCR)

REQUIREMENTS BULLETIN 737-57A1345
ALERT  ALERT
WING  UPPER LINK
NACELLE STRUT
DIAGONAL (1
BRACE
2887575
FIGURE 6: GENERAL VISUAL INSPECTION OF THE STRUT TO WING - DIAGONAL BRACE - RIGHT
(SHEET 1 OF 2)
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### Page 29

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)1311A1730-( )DIAGONAL BRACEInspect1
(a) Do a general visual inspection of the diagonal brace for any crack.
FIGURE 6: GENERAL VISUAL INSPECTION OF THE STRUT TO WING - DIAGONAL BRACE - RIGHT
(SHEET 2 OF 2)
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REQUIREMENTS BULLETIN 737-57A1345
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