# Boeing Alert Service Bulletin 737-53A1319: Revision 2

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- Document: [Boeing Alert Service Bulletin 737-53A1319](https://openairdocs.org/service-documents/boeing/737-53a1319.md)
- Title as filed: U.S. DOT/FAA - Service Bulletin 737-53A1319 Revision 02
- Pages: 62
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## Text

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### Page 1

Commercial 
Airplanes
737
Service Bulletin
ALERT
Number: 737-53A1319
Original Issue: April 04, 2011
Revision 2: April 04, 2014
ATA System: 5331
SUBJECT: FUSELAGE - Skin - Crown Skin Lap Joint - Inspection for Lower Row Cracks at Stringer
S-4, Between Body Station 360 and Body Station 1016
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 © 2011 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Unpublished Work.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: April 04, 2011
737-53A1319Revision 2: April 04, 2014
1 of 62
4.0

### Page 2

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Table of Contents
Revision Transmittal Sheet ............................................ 5
Summary ...................................................... 7
1. PLANNING INFORMATION ........................................ 1 1
A. Effectivity ............................................... 1 1
1. Airplanes ............................................ 1 1
2. Spares Affected ........................................ 1 6
B. Concurrent Requirements ...................................... 1 6
C. Reason ................................................ 1 6
D. Description .............................................. 1 7
E. Compliance .............................................. 1 8
F. Approval ............................................... 2 5
G. Manpower .............................................. 2 6
H. Weight and Balance Changes .................................... 2 7
I. Electrical Load Data ......................................... 2 7
J. References .............................................. 2 7
1. Existing Data: ......................................... 2 7
2. Data Supplied with this Service Bulletin: ........................... 2 7
3. Installation Drawings Used in the Preparation of this Service Bulletin: ........... 2 7
K. Publications Affected ........................................ 2 8
L. Interchangeability and Intermixability of Parts ........................... 2 8
M. Software Accomplishment Summary ................................ 2 8
2. MATERIAL INFORMATION ........................................ 2 9
A. Material - Price and Availability ................................... 2 9
B. Industry Support Information .................................... 2 9
C. Parts Necessary for Each Airplane ................................. 2 9
1. Kits/Parts ............................................ 2 9
2. Parts and Materials Supplied by the Operator ........................ 2 9
3. Parts Modified and Reidentified ................................ 2 9
4. Parts Removed and Not Replaced .............................. 2 9
D. Parts Necessary to Change Spares ................................. 2 9
E. Special Tooling - Price and Availability ............................... 2 9
F. Special Tooling Necessary to do this Service Bulletin ....................... 2 9
3. ACCOMPLISHMENT INSTRUCTIONS .................................. 3 1
A. GENERAL INFORMATION ..................................... 3 1
B. WORK INSTRUCTIONS ....................................... 3 3
FIGURE 1: EXTERNAL INSPECTION ................................... 4 2
FIGURE 2: INTERNAL INSPECTION ................................... 4 4
FIGURE 3: CONFIRMING A CRACK INDICATION ............................ 4 8
FIGURE 4: FIGURE DELETED AT REVISION 2 ............................. 5 2
FIGURE 5: INSPECTION ZONES [Group 1-2, 4-7] ............................ 5 3
FIGURE 6: INSPECTION ZONES [Group 3] ................................ 5 6
FIGURE 7: INSPECTION ZONES ..................................... 5 7
FIGURE 8: INTERNAL GENERAL VISUAL INSPECTION - LOWER SKIN PANEL AT S-4R, BS 908 TO BS
1016 [Group 1, 4, 6] ...................................... 6 0
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### Page 5

Commercial 
Airplanes
737
Service Bulletin
ALERT
Revision Transmittal SheetNumber: 737-53A1319Original Issue: April 04, 2011
Revision 2: April 04, 2014
ATA System: 5331
SUBJECT: FUSELAGE - Skin - Crown Skin Lap Joint - Inspection for Lower Row Cracks at Stringer
S-4, Between Body Station 360 and Body Station 1016
This revision includes all pages of the service bulletin.
COMPLIANCE INFORMATION RELATED TO THIS REVISION
Federal Aviation Administration (FAA) Airworthiness Directive AD 2011-08-51 is related to this service bulletin.
The Federal Aviation Administration (FAA) will possibly release an additional Airworthiness Directive related to
this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service
bulletin mandatory.
More work is necessary on the airplanes inspected in accordance with the Original Issue or Revision 1 of this
service bulletin.
Additional work requirements are in Paragraph 1.E., Compliance, Tables 3, 4, 5, and 6.
Optional repeat inspection intervals are in Paragraph 1.E., Compliance, Table 2.
REASON FOR REVISION
This revision is sent to define new groups, provide new compliance tables, and add more inspections. In addition,
the second external inspection in Figure 4 is deleted.
The data given in Information Notice 737-53A1319 IN-01 is included in this revision.
These sections were changed:
1. In Summary, changed Background, Action, Compliance, Industry Support Information, and Summary
Figure.
2. In Paragraph 1.A.1., Airplanes, added Service Bulletin Index and defined new Groups.
3. In Paragraph 1.C., Reason, added fleet findings, Widespread Fatigue Damage (WFD) statement,
Service Related Problem (SRP) number, and Fleet Team Digest (FTD) number.
4. In Paragraph 1.D., Description, changed to agree with Compliance and Work Instructions sections and
added Maintenance Zone tables.
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### Page 6

5. In Paragraph 1.E., Compliance - added Airworthiness Directive (AD) effective date, inspection exceptions,
new compliance requirements, and compliance tables.
6. In Paragraph 1.F., Approval, changed alternative method of compliance (AMOC) approval statement.
7. In Paragraph 1.G., Manpower, changed Manpower tables.
8. In Paragraph 1.J., References, changed Existing Data.
9. In Paragraph 1.M., Software Accomplishment Summary, added software accomplishment section.
10. In Paragraph 2.B., Industry Support Information, added warranty statement.
11. In Paragraph 3.A., General Information, changed Notes.
12. In Paragraph 3.B., Work Instructions, changed to agree with Description and Compliance sections.
13. Figure 1, added locator and changed Non-Destructive Testing (NDT) from Figure to Procedure to agree
with the 737 NDT Manual.
14. Figure 2, added locator, changed illustration, and added inspection note for locations obstructed by
the internal structures.
15. Figure 3, added locator, changed illustration, added inspection note for locations obstructed by the
internal structures and removed the optional open hole rotary probe inspection.
16. Figure 4, deleted figure because Boeing has determined that the second external inspection is no
longer required.
17. Figure 5, added Group heading.
18. Figures 6-7, added new figures for inspection zones.
19. Figure 8, added new figure for internal general visual inspection.
Vertical lines are put on the left edge of each page, except in Paragraph 1.A., Effectivity and format changes,
to show the location of all content changes.
Pages with no vertical lines have no important changes.
REVISION HISTORY
April 04, 2011Original Issue:
April 08, 2011Revision 1:
April 04, 2014Revision 2:
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ALERTALERT

### Page 7

Commercial 
Airplanes
737
Service Bulletin
ALERT
SummaryNumber: 737-53A1319Original Issue: April 04, 2011
Revision 2: April 04, 2014
ATA System: 5331
SUBJECT: FUSELAGE - Skin - Crown Skin Lap Joint - Inspection for Lower Row Cracks at Stringer
S-4, Between Body Station 360 and Body Station 1016
THIS BULLETIN 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 SERVICE BULLETIN TO
THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO
THE NEW OWNER.
CONCURRENT REQUIREMENTS
None.
BACKGROUND
A 737-300 airplane, outside of the effectivity of Service Bulletin (SB) 737-53A1255, experienced a rapid
decompression when the lap joint at stringer S-4L between BS 664 - BS 727 cracked and opened up. Investigation
shows that the cracks were caused by fatigue cracks in the lower skin at the lower row of fasteners in the lap
joint. The airplane had 39,781 total flight cycles and 48,740 total flight hours. This service bulletin gives instructions
to inspect the lower row of fasteners at stringer S-4R and S-4L, from BS 360 to BS 908 for cracks in the lower
skin of the lap joint. If cracks at this location go undetected, the cracks could link up, resulting in an uncontrolled
decompression.
After the original issue of this service bulletin, Non-Destructive Testing (NDT) inspections have resulted in
additional fleet findings in the skin at the lap joint lower fastener row. Fourteen (14) aircraft were reported with
crack indications between 38,222 - 44,784 total flight cycles and 46,822 - 54,434 total hours.
Further investigation into these reports of cracks in the lower skin at the lap joint lower row fastener hole have
identified small cracks and cracks from scratches. There were nine (9) findings with scratch cracks. Scratch
cracks form in the lower skin at the lap joint lower fastener row, local to the hole, but may not intersect the hole.
Internal crack confirmation common to doublers and tear straps using hole probe inspections have been removed
from this service bulletin because scratch cracks may not intersect the fastener hole.
Airplanes prior to Line Number 2553 are covered by Service Bulletin (SB) 737-53A1255. This SB covers airplanes
from Line Number 2553 to 3132.
The lap splice - fuselage lower fastener hole in the lower skin has been determined to be structure that is
susceptible to Widespread Fatigue Damage (WFD).
Boeing Service Related Problem (SRP) 737-SRP-53-0330 is related to this service bulletin.
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### Page 8

Boeing Fleet Team Digest (FTD) 737 FTD 53-09004 is related to this service bulletin.
This table is provided to operators for planning purposes only. Refer to the applicable sections for more
information.
ReferenceAffectedPlanning Data
Paragraph 1.A.2., Spares AffectedNoSpares Affected
Paragraph 1.E., Compliance and Paragraph
1.F., Approval
YesAD Related
Paragraph 1.H., Weight and Balance 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
NoOperator Supplied Parts/Material
Paragraph 2.F., Special Tooling Necessary to
do this Service Bulletin
NoSpecial Tooling Required
ACTION
This service bulletin gives instructions to do as follows:
1. Part 1: (Option 1) External eddy current inspection at S-4L and S-4R, BS 360 to BS 908 for cracks,
excluding BS 540 to BS 727E for Group 3 airplanes.
Or
Part 1: (Option 2) Internal detailed and eddy current inspections at S-4L and S-4R, BS 360 to BS 908
for cracks, excluding BS 540 to BS 727E for Group 3 airplanes.
2. Part 2: One-time internal detailed and eddy current inspections at S-4L and S-4R, BS 360 to BS 908
for cracks, excluding BS 540 to BS 727E for Group 3 airplanes.
3. Group 2-3, 5, 7:
Part 3: One-time internal detailed and eddy current inspections at S-4R, BS 908 to BS 1016 for cracks.
4. Group 2-3, 5, 7:
Part 4: (Option 1) External eddy current inspection at S-4R, BS 908 to BS 1016 for cracks.
Or
Part 4: (Option 2) Internal detailed and eddy current inspections at S-4R, BS 908 to BS 1016 for cracks.
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### Page 9

5. Group 1, 4, 6:
Part 5: Internal general visual inspection of lower skin panel at S-4R, BS 908 to BS 1016 for open or
closed pockets.
EFFECTIVITY
737-300, 737-400, and 737-500 Airplanes. Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplanes.
COMPLIANCE
The Federal Aviation Administration (FAA) will possibly release an additional Airworthiness Directive related to
this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service
bulletin mandatory.
Federal Aviation Administration (FAA) Airworthiness Directive AD 2011-08-51 is related to this service bulletin.
The effective date of AD 2011-08-51 is June 2, 2011.
Refer to Paragraph 1.E., Compliance.
INDUSTRY SUPPORT INFORMATION
Boeing warranty remedies are not available for the inspection and/or repair procedures given in this service
bulletin.
MANPOWER
Refer to Paragraph 1.G., Manpower.
MATERIAL INFORMATION
None.
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### Page 10 (OCR)

BOEING SERVICE BULLETIN 737-53A1319
ALERT  ALERT
STA
1016
STA
908
STA
540
STA
360  UPPER SKIN AND DOUBLER
S-4R •
S-4L
* * SAUR
LOWER SKIN
TEAR STRAP
S-4L/R
INSPECT LAP JOINT BETWEEN
STA 360 AND STA 908 AT S-4L
AND S-4R AND BETWEEN STA
908 AND STA 1016 AT S-4R
CRACKS SHOWN IN THE LOWER SKIN
AT THE LOWER ROW OF FASTENERS
TYPICAL LAP JOINT CONFIGURATION  2068118
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### Page 11

Commercial 
Airplanes
737
Service Bulletin
ALERT
Number: 737-53A1319
Original Issue: April 04, 2011
Revision 2: April 04, 2014
ATA System: 5331
SUBJECT: FUSELAGE - Skin - Crown Skin Lap Joint - Inspection for Lower Row Cracks at Stringer
S-4, Between Body Station 360 and Body Station 1016
THIS BULLETIN 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 SERVICE BULLETIN TO
THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO
THE NEW OWNER.
1.    PLANNING INFORMATION
A. Effectivity
1. Airplanes
This service bulletin is for the airplane(s) shown below.
Refer to Service Bulletin Index D6-19567 Part 3 for Airplane Variable Number, Line Number, and
Serial Number data.
DESCRIPTIONCONFIGURATIONGROUP
737-300 airplanes with specific inspection zones S-4R and S-4L, BS
360 to BS 908 and internal general visual inspection for open or
closed pockets at S-4R, BS 908 to BS 1016.
-1
737-300 airplanes with specific inspection zones S-4R and S-4L, BS
360 to BS 908 and S-4R, BS 908 to BS 1016.
-2
737-300 airplanes with specific inspection zones S-4R and S-4L, BS
360 to BS 540 and BS 727E to BS 908 and S-4R, BS 908 to BS
1016.
-3
737-400 airplanes with specific inspection zones S-4R and S-4L, BS
360 to BS 908 and internal general visual inspection for open or
closed pockets at S-4R, BS 908 to BS1016.
-4
737-400 airplanes with specific inspection zones S-4R and S-4L, BS
360 to BS 908 and S-4R, BS 908 to BS 1016.
-5
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### Page 12

DESCRIPTIONCONFIGURATIONGROUP
737-500 airplanes with specific inspection zones S-4R and S-4L, BS
360 to BS 908 and internal general visual inspection for open or
closed pockets at S-4R, BS 908 to BS 1016.
-6
737-500 airplanes with specific inspection zones S-4R and S-4L, BS
360 to BS 908 and S-4R, BS 908 to BS 1016.
-7
Airplane Models:
737-300, 737-400, 737-500
GroupVariable Number
5PJ552 - PJ559
4PJ560 - PJ561
4PJ601 - PJ615
4PJ811
4PJ816 - PJ817
2PM543 - PM550
2PP518 - PP520
1PP876 - PP877
2PQ297 - PQ299
2PQ345 - PQ348
2PQ370 - PQ373
2PQ391 - PQ393
1PQ394 - PQ395
2PQ408 - PQ410
2PQ414
1PQ415 - PQ418
2PQ431 - PQ438
2PQ447
1PQ448
1PQ451
1PQ454
2PQ473 - PQ475
2PQ772
2PQ933 - PQ935
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GroupVariable Number
2PQ951
2PQ971
1PQ972 - PQ997
1PR001 - PR017
1PR021 - PR034
1PR041 - PR045
1PR061 - PR072
1PR077 - PR082
1PR091 - PR092
1PR096
1PR101
1PR121 - PR122
1PR131 - PR132
1PR141 - PR143
1PR161 - PR172
1PR181
2PS617 - PS629
1PS630
2PS704 - PS706
3PS763 - PS799
2PS811
2PS836 - PS837
2PS841 - PS846
2PS851 - PS852
2PS856
2PS861 - PS863
2PS866 - PS868
1PS871 - PS874
2PS896 - PS897
3PS901 - PS906
2PS907 - PS924
1PS925 - PS941
2PS956 - PS957
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GroupVariable Number
1PS961 - PS963
1PS971 - PS978
7PT012 - PT014
6PT015
7PT029 - PT031
7PT064
7PT126 - PT131
6PT132 - PT138
7PT188
7PT307 - PT309
7PT513 - PT517
7PT585
6PT586
7PT643 - PT644
7PT656
6PT681 - PT685
7PT716 - PT717
7PT721
6PT722 - PT725
7PT801 - PT834
7PT851 - PT853
6PT854
7PT871 - PT876
6PT877 - PT886
6PT901 - PT930
7PT971 - PT973
6PT981 - PT985
6PT996
6PU301
6PU311 - PU313
5PV204 - PV205
4PV206 - PV209
5PV226
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GroupVariable Number
4PV227 - PV229
5PV284 - PV285
4PV286 - PV287
5PV296
5PV301
4PV302
4PV351
4PV356 - PV357
5PW086 - PW088
4PW168 - PW171
5PW245 - PW251
4PW252
5PW262
4PW263 - PW264
5PW271 - PW275
4PW276
5PW282 - PW292
5PW401 - PW403
4PW404 - PW408
5PW411 - PW413
4PW414 - PW418
4PW421 - PW424
4PW431 - PW435
4PW441 - PW450
5PW521 - PW522
5PW524 - PW525
5PW527 - PW530
5PW547 - PW550
5PW621 - PW622
5PW635 - PW637
4PW831
4PW851 - PW856
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### Page 16

2. Spares Affected
None.
B. Concurrent Requirements
None.
C. Reason
A 737-300 airplane, outside of the effectivity of Service Bulletin (SB) 737-53A1255, experienced a rapid
decompression when the lap joint at stringer S-4L between BS 664 - BS 727 cracked and opened up.
Investigation shows that the cracks were caused by fatigue cracks in the lower skin at the lower row
of fasteners in the lap joint. The airplane had 39,781 total flight cycles and 48,740 total flight hours.
This service bulletin gives instructions to inspect the lower row of fasteners at stringer S-4R and S-4L,
from BS 360 to BS 908 for cracks in the lower skin of the lap joint. If cracks at this location go undetected,
the cracks could link up, resulting in an uncontrolled decompression.
After the original issue of this service bulletin, Non-Destructive Testing (NDT) inspections have resulted
in additional fleet findings in the skin at the lap joint lower fastener row. Fourteen (14) aircraft were
reported with crack indications between 38,222 - 44,784 total flight cycles and 46,822 - 54,434 total
hours.
Further investigation into these reports of cracks in the lower skin at the lap joint lower row fastener
hole have identified small cracks and cracks from scratches. There were nine (9) findings with scratch
cracks. Scratch cracks form in the lower skin at the lap joint lower fastener row, local to the hole, but
may not intersect the hole. Internal crack confirmation common to doublers and tear straps using hole
probe inspections have been removed from this service bulletin because scratch cracks may not
intersect the fastener hole.
Airplanes prior to Line Number 2553 are covered by Service Bulletin (SB) 737-53A1255. This SB covers
airplanes from Line Number 2553 to 3132.
The lap splice - fuselage lower fastener hole in the lower skin has been determined to be structure that
is susceptible to Widespread Fatigue Damage (WFD).
Boeing Service Related Problem (SRP) 737-SRP-53-0330 is related to this service bulletin.
Boeing Fleet Team Digest (FTD) 737 FTD 53-09004 is related to this service bulletin.
Revision 1 was sent to correct a figure label and to clarify figure details. Manpower estimates are also
included.
Revision 2 is sent to define new groups, provide new compliance tables, and add more inspections.
In addition, the second external inspection in Figure 4 is deleted.
The data given in Information Notice 737-53A1319 IN-01 is included in Revision 2.
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### Page 17

D. Description
This service bulletin gives instructions to do as follows:
1. Part 1: (Option 1) External eddy current inspection at S-4L and S-4R, BS 360 to BS 908 for cracks,
excluding BS 540 to BS 727E for Group 3 airplanes.
Or
Part 1: (Option 2) Internal detailed and eddy current inspections at S-4L and S-4R, BS 360 to BS
908 for cracks, excluding BS 540 to BS 727E for Group 3 airplanes.
2. Part 2: One-time internal detailed and eddy current inspections at S-4L and S-4R, BS 360 to BS
908 for cracks, excluding BS 540 to BS 727E for Group 3 airplanes.
3. Group 2-3, 5, 7:
Part 3: One-time internal detailed and eddy current inspections at S-4R, BS 908 to BS 1016 for
cracks.
4. Group 2-3, 5, 7:
Part 4: (Option 1) External eddy current inspection at S-4R, BS 908 to BS 1016 for cracks.
Or
Part 4: (Option 2) Internal detailed and eddy current inspections at S-4R, BS 908 to BS 1016 for
cracks.
5. Group 1, 4, 6:
Part 5: Internal general visual inspection of lower skin panel at S-4R, BS 908 to BS 1016 for open
or closed pockets.
Revision 2 - More work is necessary on airplanes inspected in accordance with the Original Issue or
Revision 1 of this service bulletin.
Additional work requirements are in Paragraph 1.E., Compliance, Tables 3, 4, 5, and 6.
Optional repeat inspection intervals are in Paragraph 1.E., Compliance, Table 2.
The work in this service bulletin is done in the maintenance zone(s) given below.
Group 1-3:
Affected Maintenance Zones
ZoneModel
107, 108737-300
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Group 4-5:
Affected Maintenance Zones
ZoneModel
107, 108737-400
Group 6-7:
Affected Maintenance Zones
ZoneModel
107, 108737-500
E. Compliance
The Federal Aviation Administration (FAA) will possibly release an additional Airworthiness Directive
related to this service bulletin. The Airworthiness Directive will make the compliance tasks and times
given in this service bulletin mandatory.
Federal Aviation Administration (FAA) Airworthiness Directive AD 2011-08-51 is related to this service
bulletin. The effective date of AD 2011-08-51 is June 2, 2011.
If the airplane has had a skin panel replaced common to the subject lap joint areas, the compliance
times for inspection of the lower skin may be affected. Contact Boeing for alternate lap joint lower row
inspections for the lap joint areas affected by skin panel replacements.
Inspection Exceptions:
1. If an existing external repair doubler is common to the inspection area of the lap joint lower fastener
row and meets the criteria shown below, then it is not required to inspect the lower skin at the lap
joint lower fastener row under the existing repair doubler.
a. The installed repair was approved by the FAA or by a Boeing Authorized Representative who
was authorized by the FAA to make such findings.
b. The installed repair extends a minimum of three rows of fasteners above the chem-mill step
and three rows of fasteners below the lap joint lower row.
2. If the repair does not meet the above conditions, then inspect the lower skin lap joint lower row
internally in the area covered by the doubler in accordance with FIGURE 2.
If any inspection has not been accomplished in accordance with the Original Issue or Revision 1 of this
service bulletin, then Table 1 requirements must be accomplished before starting Table 2 requirements.
Follow-on repetitive inspections may be accomplished using Table 2.
Do the required actions 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.
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Table 1: Eddy Current Inspections for Cracks at S-4L and S-4R, BS 360 to BS 908
Repeat Interval (Not
to Exceed)
Compliance Time (Whichever Occurs
Later)
ActionCondition
-Within 20 days after
the effective date of
AD 2011-08-51
Before 30,000 total
flight cycles
Do PART 1: (OP-
TION 1) EXTERNAL
EDDY CURRENT
INSPECTION AT S-
4L AND S-4R, BS
360 TO BS 908 for
cracks.
Airplanes with less
than 30,000 total
flight cycles as of the
effective date of AD
2011-08-51
OR
Do PART 1: (OP-
TION 2) INTERNAL
DETAILED AND ED-
DY CURRENT IN-
SPECTIONS AT S-
4L AND S-4R, BS
360 TO BS 908 for
cracks.
-Within 20 days after
the effective date of
AD 2011-08-51
-Do PART 1: (OP-
TION 1) EXTERNAL
EDDY CURRENT
INSPECTION AT S-
4L AND S-4R, BS
360 TO BS 908 for
cracks.
Airplanes with
30,000 or more total
flight cycles and less
than 35,000 total
flight cycles as of the
effective date of AD
2011-08-51
OR
Do PART 1: (OP-
TION 2) INTERNAL
DETAILED AND ED-
DY CURRENT IN-
SPECTIONS AT S-
4L AND S-4R, BS
360 TO BS 908 for
cracks.
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Table 1: Eddy Current Inspections for Cracks at S-4L and S-4R, BS 360 to BS 908
Repeat Interval (Not
to Exceed)
Compliance Time (Whichever Occurs
Later)
ActionCondition
-Within 5 days after
the effective date of
AD 2011-08-51
-Do PART 1: (OP-
TION 1) EXTERNAL
EDDY CURRENT
INSPECTION AT S-
4L AND S-4R, BS
360 TO BS 908 for
cracks.
Airplanes with
35,000 or more total
flight cycles as of the
effective date of AD
2011-08-51
OR
Do PART 1: (OP-
TION 2) INTERNAL
DETAILED AND ED-
DY CURRENT IN-
SPECTIONS AT S-
4L AND S-4R, BS
360 TO BS 908 for
cracks.
500 flight cycles--Repeat inspection in
PART 1: (OPTION 1)
EXTERNAL EDDY
CURRENT INSPEC-
TION AT S-4L AND
S-4R, BS 360 TO BS
908 for cracks.
CONDITION 1:
NO CRACK FOUND
---OR
500 flight cycles--Repeat inspections
in PART 1: (OPTION
2) INTERNAL DE-
TAILED AND EDDY
CURRENT INSPEC-
TIONS AT S-4L AND
S-4R, BS 360 TO BS
908 for cracks.
-Before further flightContact Boeing for
repair instructions
and do the repair.
CONDITION 2:
ANY CRACK
FOUND
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Table 2: Airplanes on which any inspection specified in Table 1 or Table 2 of this service bulletin has
been accomplished - Optional Repeat Inspection Intervals
Repeat Interval (Not
to Exceed)
Compliance Time (Whichever Occurs
Later)
ActionCondition
2,000 flight cycles
until the accumula-
tion of 38,001 total
flight cycles
--Repeat inspection in
PART 1: (OPTION 1)
EXTERNAL EDDY
CURRENT INSPEC-
TION AT S-4L AND
S-4R, BS 360 TO BS
908 for cracks.
Airplanes with
38,000 total flight cy-
cles or less as of the
most recent inspec-
tion
CONDITION 1:
NO CRACK FOUND
OR
Repeat inspections
in PART 1: (OPTION
2) INTERNAL DE-
TAILED AND EDDY
CURRENT INSPEC-
TIONS AT S-4L AND
S-4R, BS 360 TO BS
908 for cracks.
1,500 flight cycles
until the accumula-
tion of 42,501 total
flight cycles
--Repeat inspection in
PART 1: (OPTION 1)
EXTERNAL EDDY
CURRENT INSPEC-
TION AT S-4L AND
S-4R, BS 360 TO BS
908 for cracks.
Airplanes with more
than 38,000 total
flight cycles but less
than or equal to
42,500 total flight cy-
cles as of the most
recent inspection
CONDITION 1:
NO CRACK FOUND OR
Repeat inspections
in PART 1: (OPTION
2) INTERNAL DE-
TAILED AND EDDY
CURRENT INSPEC-
TIONS AT S-4L AND
S-4R, BS 360 TO BS
908 for cracks.
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Table 2: Airplanes on which any inspection specified in Table 1 or Table 2 of this service bulletin has
been accomplished - Optional Repeat Inspection Intervals
Repeat Interval (Not
to Exceed)
Compliance Time (Whichever Occurs
Later)
ActionCondition
500 flight cycles--Repeat inspections
in PART 1: (OPTION
1) EXTERNAL EDDY
CURRENT INSPEC-
TION AT S-4L AND
S-4R, BS 360 TO BS
908 for cracks.
Airplanes with more
than 42,500 total
flight cycles as of the
most recent inspec-
tion
CONDITION 1:
NO CRACK FOUND
OR
Repeat inspections
in PART 1: (OPTION
2) INTERNAL DE-
TAILED AND EDDY
CURRENT INSPEC-
TIONS AT S-4L AND
S-4R, BS 360 TO BS
908 for cracks.
-Before further flightContact Boeing for
repair instructions
and do the repair.
CONDITION 2:
ANY CRACK
FOUND
Table 3: One-Time Internal Detailed and Eddy Current Inspections for Cracks at S-4L and S-4R, BS 360
to BS 908
Repeat Interval (Not
to Exceed)
Compliance Time (Whichever Occurs
Later)
ActionCondition
-Within 1,000 flight
cycles after the Revi-
sion 2 date of this
service bulletin
Before 45,000 total
flight cycles, but not
earlier than 40,000
total flight cycles
Do PART 2: ONE-
TIME INTERNAL
DETAILED AND ED-
DY CURRENT IN-
SPECTIONS AT S-
4L AND S-4R, BS
360 TO BS 908 for
cracks. (a)
All Airplanes
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Table 3: One-Time Internal Detailed and Eddy Current Inspections for Cracks at S-4L and S-4R, BS 360
to BS 908
Repeat Interval (Not
to Exceed)
Compliance Time (Whichever Occurs
Later)
ActionCondition
In accordance with
Table 1 or Table 2
--Continue repeat in-
spection in PART 1:
(OPTION 1) EXTER-
NAL EDDY CUR-
RENT INSPECTION
AT S-4L AND S-4R,
BS 360 TO BS 908
for cracks.
CONDITION 3:
NO CRACK FOUND
OR
Continue repeat in-
spections in PART 1:
(OPTION 2) INTER-
NAL DETAILED AND
EDDY CURRENT
INSPECTIONS AT
S-4L AND S-4R, BS
360 TO BS 908 for
cracks.
-Before further flightContact Boeing for
repair instructions
and do the repair.
CONDITION 4:
ANY CRACK
FOUND
(a) Accomplishment of the one-time internal inspection is an acceptable method of compliance for the accom-
plishment of one Option 1 or one Option 2 inspection specified in Table 1 or Table 2.
Group 2-3, 5, 7:
Table 4: One-Time Internal Detailed and Eddy Current Inspections for Cracks at S-4R, BS 908 TO BS
1016
Repeat Interval (Not
to Exceed)
Compliance Time (Whichever Occurs
Later)
ActionCondition
-Within 1,000 flight
cycles after the Revi-
sion 2 date of this
service bulletin
Before 76,000 total
flight cycles, but not
earlier than 75,000
total flight cycles
Do PART 3: ONE-
TIME INTERNAL
DETAILED AND ED-
DY CURRENT IN-
SPECTIONS AT S-
4R, BS 908 TO BS
1016 for cracks.
All Airplanes
--No further Table 4
work required.
CONDITION 5:
NO CRACK FOUND
Do the work in Table
5.
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Group 2-3, 5, 7:
Table 4: One-Time Internal Detailed and Eddy Current Inspections for Cracks at S-4R, BS 908 TO BS
1016
Repeat Interval (Not
to Exceed)
Compliance Time (Whichever Occurs
Later)
ActionCondition
-Before further flightContact Boeing for
repair instructions
and do the repair.
CONDITION 6:
ANY CRACK
FOUND
Group 2-3, 5, 7:
Table 5: Eddy Current Inspections for Cracks at S-4R, BS 908 TO BS 1016
Repeat Interval (Not
to Exceed)
Compliance Time (Whichever Occurs
Later)
ActionCondition
-Within 1,500 flight
cycles after the Revi-
sion 2 date of this
service bulletin
Before 76,500 total
flight cycles
Do PART 4: (OP-
TION 1) EXTERNAL
EDDY CURRENT
INSPECTION AT S-
4R, BS 908 TO BS
1016 for cracks.
All Airplanes
OR
Do PART 4: (OP-
TION 2) INTERNAL
DETAILED AND ED-
DY CURRENT IN-
SPECTIONS AT S-
4R, BS 908 TO BS
1016 for cracks.
1,500 flight cycles
until the accumula-
tion of 80,000 total
flight cycles
--Repeat inspection in
PART 4: (OPTION 1)
EXTERNAL EDDY
CURRENT INSPEC-
TION AT S-4R, BS
908 TO BS 1016 for
cracks.
CONDITION 7:
NO CRACK FOUND
THEN
500 flight cycles after
the accumulation of
80,000 total flight cy-
clesOR
Repeat inspections
in PART 4: (OPTION
2) INTERNAL DE-
TAILED AND EDDY
CURRENT INSPEC-
TIONS AT S-4R, BS
908 TO BS 1016 for
cracks.
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Group 2-3, 5, 7:
Table 5: Eddy Current Inspections for Cracks at S-4R, BS 908 TO BS 1016
Repeat Interval (Not
to Exceed)
Compliance Time (Whichever Occurs
Later)
ActionCondition
-Before further flightContact Boeing for
repair instructions
and do the repair.
CONDITION 8:
ANY CRACK
FOUND
Group 1, 4, 6:
Table 6: Internal General Visual Inspection of Lower Skin Panel at S-4R, BS 908 to BS 1016
Repeat Interval (Not
to Exceed)
Compliance Time (Whichever Occurs
Later)
ActionCondition
-Within 1,500 flight
cycles after the Revi-
sion 2 date of this
service bulletin.
Before 75,000 total
flight cycles
Do PART 5: INTER-
NAL GENERAL VI-
SUAL INSPECTION
OF LOWER SKIN
PANEL AT S-4R, BS
908 TO BS 1016 for
open or closed pock-
ets. (a)
All Airplanes
---No further work re-
quired at S-4R, BS
908 TO BS 1016.
CONDITION 9: ANY
CLOSED POCKETS
FOUND ADJACENT
TO THE S-4R LAP
JOINT, BS 908 TO
BS 1016
(b)Before further flightContact Boeing for
inspections or repair
instructions and do
the work instructed
by Boeing.
CONDITION 10:
ANY OPEN POCK-
ETS FOUND ADJA-
CENT TO THE S-4R
LAP JOINT, BS 908
TO BS 1016
(a) Refer to FIGURE 8 for illustrations of open or closed pockets.
(b) Depending on configuration information, the repair instructions may result in repetitive inspection instructions
similar to Part 3 and Part 4 for Group 2-3, 5, and 7 airplanes.
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.
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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.
In addition, the Manager of the FAA Seattle Aircraft Certification Office approves accomplishment of
the Stringer S-4L and S-4R, BS 360 to BS 908 inspections and compliance times in accordance with
Boeing Alert Service Bulletin 737-53A1319 Revision 2 as an alternative method of compliance to the
inspections required by paragraphs (g), (i) and (k) of AD 2011-08-51. All provisions of AD 2011-08-51
that are not specifically referenced in the above statement remain fully applicable and must be complied
with accordingly.
G. Manpower
The table below shows an estimate of the task hours necessary to do this inspections for each airplane.
This estimate is for direct labor only, done by an experienced crew. Adjust the estimate with operator
task hour data if necessary. The estimate does not include lost time. These are some examples of lost
time:
 Time to adjust to the workplace
 Time to schedule the work
 Time to inspect the work
 Time to cure the materials
 Time to make the parts
 Time to find the tools.
Group 1, 4, 6:
Elapsed HoursTask HoursNumber of PersonsTask
3.006.002Part 1 (Option 1)
213.504270.0020Part 1 (Option 2)
213.504270.0020Part 2
55.00550.0010Part 5
(b)(b)TOTAL FOR EACH AIRPLANE (a)
(a) Additional hours will be required for repair if any crack is found.
(b) Total hours dependent upon Parts and Options accomplished.
Group 2-3, 5, 7:
Elapsed HoursTask HoursNumber of PersonsTask
3.006.002Part 1 (Option 1)
213.504270.0020Part 1 (Option 2)
213.504270.0020Part 2
55.00550.0010Part 3
2.004.002Part 4 (Option 1)
55.00550.0010Part 4 (Option 2)
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Group 2-3, 5, 7:
Elapsed HoursTask HoursNumber of PersonsTask
(b)(b)TOTAL FOR EACH AIRPLANE (a)
(a) Additional hours will be required for repair if any crack is found.
(b) Total hours dependent upon Parts and Options accomplished.
H. Weight and Balance Changes
None.
I. Electrical Load Data
None.
J. References
1. Existing Data:
a. Boeing Service Bulletin 737-53A1255
b. Boeing Service Letter 737-SL-51-042
c. Boeing Service Related Problem (SRP) 737-SRP-53-0330
d. Federal Aviation Administration (FAA) Airworthiness Directive (AD) 2011-08-51
e. Service Bulletin Index D6-19567
f. Standard Overhaul Practices Manual (SOPM) 20-50-01
g. 737 Fleet Team Digest (FTD) 53-09004
h. 737 Non-Destructive Testing (NDT) Manual Part 6, 53-30-00 Procedure 9, Part 6, 53-30-12,
Part 6, 53-30-16
i. 737-300/400/500 Aircraft Maintenance Manual (AMM) 21-23-25, 25-21-39, 25-21-45, 25-21-71,
25-23-61, 25-24-31, 25-31-21, 25-31-31, 25-31-61, 25-40-01
2. Data Supplied with this Service Bulletin:
None.
3. Installation Drawings Used in the Preparation of this Service Bulletin:
None.
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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 does not affect FCS, therefore DTIs are not necessary.
L. Interchangeability and Intermixability of Parts
None.
M. Software Accomplishment Summary
Not affected.
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2.    MATERIAL INFORMATION
A. Material - Price and Availability
None.
B. Industry Support Information
Boeing warranty remedies are not available for the inspection and/or repair procedures given in this
service bulletin.
C. Parts Necessary for Each Airplane
1. Kits/Parts
None.
2. Parts and Materials Supplied by the Operator
None.
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
CAUTION: KEEP THE WORK AREA, WIRES AND ELECTRICAL BUNDLES CLEAN OF METAL
PARTICLES OR CONTAMINATION WHEN YOU USE TOOLS. UNWANTED MATERIAL,
METAL PARTICLES OR CONTAMINATION CAUGHT IN WIRE BUNDLES CAN CAUSE
DAMAGE TO THE BUNDLES. DAMAGED WIRE BUNDLES CAN CAUSE SPARKS OR
OTHER ELECTRICAL DAMAGE.
NOTE: 1. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for
definition of the acronyms.
2. Obey all of the warnings and cautions given in the specified manual sections.
3. Unless shown differently, these dimensions and tolerances are used:
– Linear dimensions are in inches
– Tolerance on linear dimensions, other than rivet and bolt edge margins, is plus
or minus 0.03 inch
– Tolerance on rivet and bolt edge margin is plus or minus 0.05 inch
– Angular tolerance is plus or minus 2 degrees
– Hole dimensions for standard solid rivets 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
Airplane Maintenance Manual (AMM).
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. A Detailed Inspection is defined as: An intensive examination of a specific item,
installation, or assembly to detect damage, failure, or irregularity. Available lighting
is normally supplemented with a direct source of good lighting at an intensity deemed
appropriate.
Inspection aids such as mirrors, magnifying lenses, etc. may be necessary. Surface
cleaning and elaborate procedures may be required.
7. A General Visual Inspection is defined as: A visual examination of an interior or
exterior area, installation or assembly to detect obvious damage, failure or irregularity.
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This level of inspection is made from within touching distance unless otherwise
specified. A mirror may be necessary to enhance visual access to all exposed surfaces
in the inspection area. This level of inspection is made under normally available
lighting conditions such as daylight, hangar lighting, flashlight or drop-light and may
require removal or opening of access panels or doors.
Stands, ladders or platforms may be required to gain proximity to the area being
checked.
8. 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.
9. 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.
10. The instructions in Paragraph 3.B., Work Instructions and the figures can include
operation of tools or test equipment. Boeing Engineering Tool Drawings, the Illustrated
Tool and Equipment Manual, and the Special Tool and Ground Handling Drawing
Index contain data on versions of the tools or test equipment that you can use. It is
permitted to use replaced tools. It is not permitted to use superseded tools.
11. If it is necessary to remove more parts for access, you can remove those parts. If
you can get access without removing identified parts, it is not necessary to remove
all of the identified parts. Jacking and shoring limitations must be observed.
12. Where the work instructions include installation of a kept part, a new or serviceable
part with the same part number can be installed as an alternative to the kept part.
13. If shading is used, shaded areas in Figures are to separate the non-critical and
non-authoritative information from the critical and authoritative information.
14. 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.
15. The compliance times for the actions in Paragraph 3.B., WORK INSTRUCTIONS
are in Paragraph 1.E., Compliance.
16. Inspection Exceptions:
— If an existing external repair doubler is common to the inspection area of the lap
joint lower fastener row and meets the criteria shown below, then it is not required
to inspect the lower skin at the lap joint lower fastener row under the existing
repair doubler.
— The installed repair was approved by the FAA or by a Boeing Authorized
Representative who was authorized by the FAA to make such findings.
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— The installed repair extends a minimum of three rows of fasteners above
the chem-mill step and three rows of fasteners below the lap joint lower
row.
— If the repair does not meet the above conditions, then inspect the lower skin lap
joint lower row internally in the area covered by the doubler in accordance with
FIGURE 2.
B. WORK INSTRUCTIONS
1. Do PART 1: (OPTION 1) EXTERNAL EDDY CURRENT INSPECTION AT S-4L AND S-4R, BS
360 TO BS 908 for cracks.
Or
Do PART 1: (OPTION 2) INTERNAL DETAILED AND EDDY CURRENT INSPECTIONS AT S-4L
AND S-4R, BS 360 TO BS 908 for cracks.
CONDITION 1: NO CRACK FOUND
a. Repeat inspection in PART 1: (OPTION 1) EXTERNAL EDDY CURRENT INSPECTION AT
S-4L AND S-4R, BS 360 TO BS 908 for cracks.
Or
Repeat inspections in PART 1: (OPTION 2) INTERNAL DETAILED AND EDDY CURRENT
INSPECTIONS AT S-4L AND S-4R, BS 360 TO BS 908 for cracks.
CONDITION 2: ANY CRACK FOUND
a. Contact Boeing for repair instructions and do the repair.
2. Do PART 2: ONE-TIME INTERNAL DETAILED AND EDDY CURRENT INSPECTIONS AT S-4L
AND S-4R, BS 360 TO BS 908 for cracks.
CONDITION 3: NO CRACK FOUND
a. Continue repeat inspection in PART 1: (OPTION 1) EXTERNAL EDDY CURRENT
INSPECTION AT S-4L AND S-4R, BS 360 TO BS 908 for cracks.
Or
Continue repeat inspections in PART 1: (OPTION 2) INTERNAL DETAILED AND EDDY
CURRENT INSPECTIONS AT S-4L AND S-4R, BS 360 TO BS 908 for cracks.
CONDITION 4: ANY CRACK FOUND
a. Contact Boeing for repair instructions and do the repair.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
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ALERTALERT

### Page 34

3. Group 2-3, 5, 7:
Do PART 3: ONE-TIME INTERNAL DETAILED AND EDDY CURRENT INSPECTIONS AT S-4R,
BS 908 TO BS 1016 for cracks.
CONDITION 5: NO CRACK FOUND
a. Do PART 4: (OPTION 1) EXTERNAL EDDY CURRENT INSPECTION AT S-4R, BS 908 TO
BS 1016 for cracks.
Or
Do PART 4: (OPTION 2) INTERNAL DETAILED AND EDDY CURRENT INSPECTIONS AT
S-4R, BS 908 TO BS 1016 for cracks.
CONDITION 6: ANY CRACK FOUND
a. Contact Boeing for repair instructions and do the repair.
4. Group 2-3, 5, 7:
Do PART 4: (OPTION 1) EXTERNAL EDDY CURRENT INSPECTION AT S-4R, BS 908 TO BS
1016 for cracks.
Or
Do PART 4: (OPTION 2) INTERNAL DETAILED AND EDDY CURRENT INSPECTIONS AT S-4R,
BS 908 TO BS 1016 for cracks.
CONDITION 7: NO CRACK FOUND
a. Repeat inspection in PART 4: (OPTION 1) EXTERNAL EDDY CURRENT INSPECTION AT
S-4R, BS 908 TO BS 1016 for cracks.
Or
Repeat inspections in PART 4: (OPTION 2) INTERNAL DETAILED AND EDDY CURRENT
INSPECTIONS AT S-4R, BS 908 TO BS 1016 for cracks.
CONDITION 8: ANY CRACK FOUND
a. Contact Boeing for repair instructions and do the repair.
5. Group 1, 4, 6:
Do PART 5: INTERNAL GENERAL VISUAL INSPECTION OF LOWER SKIN PANEL AT S-4R,
BS 908 TO BS 1016 for open or closed pockets.
CONDITION 9: ANY CLOSED POCKETS FOUND ADJACENT TO THE S-4R LAP JOINT, BS
908 TO BS 1016
a. No further work required at S-4R, BS 908 TO BS 1016.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
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ALERTALERT

### Page 35

CONDITION 10: ANY OPEN POCKETS FOUND ADJACENT TO THE S-4R LAP JOINT, BS 908
TO BS 1016
a. Contact Boeing for inspections or repair instructions and do the work instructed by Boeing.
NOTE: Depending on configuration information, the repair instructions may result in repetitive
inspection instructions similar to Part 3 and Part 4 for Group 2-3, 5, and 7 airplanes.
PART 1: (OPTION 1) EXTERNAL EDDY CURRENT INSPECTION AT S-4L AND S-4R, BS 360 TO
BS 908
1. Group 1-2, 4-7:
Do the external eddy current inspection for cracks in the lower skin lap joint lower fastener row at
S-4L and S-4R from BS 360 to BS 908 in accordance with FIGURE 5 inspection zones.
2. Group 3:
Do the external eddy current inspection for cracks in the lower skin lap joint lower fastener row at
S-4L and S-4R from BS 360 to BS 540 and BS 727E to BS 908 in accordance with FIGURE 6
inspection zones.
3. Do the external eddy current inspection for cracks along the centerline of the lap joint lower fastener
row at stringers S-4L and S-4R in accordance with FIGURE 1.
4. Optional. Airplanes with any crack indication when external eddy current inspections are
accomplished, do internal eddy current inspections at crack indication in accordance with FIGURE
3 to confirm crack indications.
5. Put the airplane back to a serviceable condition.
PART 1: (OPTION 2) INTERNAL DETAILED AND EDDY CURRENT INSPECTIONS AT S-4L AND
S-4R, BS 360 TO BS 908
1. Remove and keep interior equipment at the inspection body station locations. Refer to the applicable
AMM reference below as an accepted procedure.
737-300/-400/-500 AMM SubjectEquipment
737-300/400/500 AMM 25-31-21Galley No. 2
737-300/400/500 AMM 25-31-31Galley No. 3
737-300/400/500 AMM 25-31-61Galley No. 6
737-300/400/500 AMM 25-40-01Lavatory
737-300/400/500 AMM 25-21-45Sculptured Ceiling Panels
737-300/400/500 AMM 25-21-71Lowered Ceiling Panels
737-300/400/500 AMM 25-21-39Sidewall and Ceiling Insulation
737-300/400/500 AMM 25-24-31Overhead Stowage Bins
737-300/400/500 AMM 25-23-61Passenger Service Units
737-300/400/500 AMM 21-23-25Overhead Air Distribution Duct
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
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ALERTALERT

### Page 36

2. Group 1-2, 4-7:
a. Do internal detailed and eddy current inspections for cracks in the lower skin at the lap joint
lower fastener row at S-4L and S-4R from BS 360 to BS 908 in accordance with FIGURE 5
inspection zones.
3. Group 3:
a. Do internal detailed and eddy current inspections for cracks in the lower skin at the lap joint
lower fastener row at S-4L and S-4R from BS 360 to BS 540 and BS 727E to BS 908 in
accordance with FIGURE 6 inspection zones.
4. Do internal detailed and eddy current inspections for cracks in the lower skin at the lap joint lower
fastener row at S-4L and S-4R in accordance with FIGURE 2.
a. At locations where the stringer channel prevents the inspection probe from scanning 360
degrees around the fastener formed tail, do an internal eddy current inspection for cracks in
the lower skin in accordance with FIGURE 2, View A-A.
NOTE: Inspection procedures 737 NDT Manual Part 6, 53-30-12 and 737 NDT Manual Part 6,
53-30-16 show limited effectivity. The inspections applicable to the lower skin at the lap
joint lower fastener row at stringers S-4L and S-4R in these procedures are applicable
to the full effectivity in this service bulletin.
5. Install kept interior equipment at the inspection body station locations. Refer to the applicable AMM
reference below as an accepted procedure.
737-300/-400/-500 AMM SubjectEquipment
737-300/400/500 AMM 25-31-21Galley No. 2
737-300/400/500 AMM 25-31-31Galley No. 3
737-300/400/500 AMM 25-31-61Galley No. 6
737-300/400/500 AMM 25-40-01Lavatory
737-300/400/500 AMM 25-21-45Sculptured Ceiling Panels
737-300/400/500 AMM 25-21-71Lowered Ceiling Panels
737-300/400/500 AMM 25-21-39Sidewall and Ceiling Insulation
737-300/400/500 AMM 25-24-31Overhead Stowage Bins
737-300/400/500 AMM 25-23-61Passenger Service Units
737-300/400/500 AMM 21-23-25Overhead Air Distribution Duct
6. Put the airplane back to a serviceable condition.
PART 2: ONE-TIME INTERNAL DETAILED AND EDDY CURRENT INSPECTIONS AT S-4L AND
S-4R, BS 360 TO BS 908
1. Remove and keep interior equipment at the inspection body station locations. Refer to the applicable
AMM reference below as an accepted procedure.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: April 04, 2011
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ALERTALERT

### Page 37

NOTE: Accomplishment of the one-time internal inspection is an acceptable method of compliance
for the accomplishment of one Option 1 or one Option 2 inspection specified in PART 1.
737-300/-400/-500 AMM SubjectEquipment
737-300/400/500 AMM 25-31-21Galley No. 2
737-300/400/500 AMM 25-31-31Galley No. 3
737-300/400/500 AMM 25-31-61Galley No. 6
737-300/400/500 AMM 25-40-01Lavatory
737-300/400/500 AMM 25-21-45Sculptured Ceiling Panels
737-300/400/500 AMM 25-21-71Lowered Ceiling Panels
737-300/400/500 AMM 25-21-39Sidewall and Ceiling Insulation
737-300/400/500 AMM 25-24-31Overhead Stowage Bins
737-300/400/500 AMM 25-23-61Passenger Service Units
737-300/400/500 AMM 21-23-25Overhead Air Distribution Duct
2. Group 1-2, 4-7:
a. Do internal detailed and eddy current inspections for cracks in the lower skin at the lap joint
lower fastener row at S-4L and S-4R from BS 360 to BS 908 in accordance with FIGURE 5
inspection zones.
3. Group 3:
a. Do internal detailed and eddy current inspections for cracks in the lower skin at the lap joint
lower fastener row at S-4L and S-4R from BS 360 to BS 540 and BS 727E to BS 908 in
accordance with FIGURE 6 inspection zones.
4. Do internal detailed and eddy current inspections for cracks in the lower skin at the lap joint lower
fastener row at S-4L and S-4R in accordance with FIGURE 2.
a. At locations where the stringer channel prevents the inspection probe from scanning 360
degrees around the fastener formed tail, do an internal eddy current inspection for cracks in
the lower skin in accordance with FIGURE 2, View A-A.
NOTE: Inspection procedures 737 NDT Manual Part 6, 53-30-12 and 737 NDT Manual Part 6,
53-30-16 show limited effectivity. The inspections applicable to the lower skin at the lap
joint lower fastener row at stringers S-4L and S-4R in these procedures are applicable
to the full effectivity in this service bulletin.
5. Install kept interior equipment at the inspection body station locations. Refer to the applicable AMM
reference below as an accepted procedure.
737-300/-400/-500 AMM SubjectEquipment
737-300/400/500 AMM 25-31-21Galley No. 2
737-300/400/500 AMM 25-31-31Galley No. 3
Export Controlled ECCN: 9E991 - BOEING
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Work - See page 1 for details.
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ALERTALERT

### Page 38

737-300/-400/-500 AMM SubjectEquipment
737-300/400/500 AMM 25-31-61Galley No. 6
737-300/400/500 AMM 25-40-01Lavatory
737-300/400/500 AMM 25-21-45Sculptured Ceiling Panels
737-300/400/500 AMM 25-21-71Lowered Ceiling Panels
737-300/400/500 AMM 25-21-39Sidewall and Ceiling Insulation
737-300/400/500 AMM 25-24-31Overhead Stowage Bins
737-300/400/500 AMM 25-23-61Passenger Service Units
737-300/400/500 AMM 21-23-25Overhead Air Distribution Duct
6. Put the airplane back to a serviceable condition.
Group 2-3, 5, 7:
PART 3: ONE-TIME INTERNAL DETAILED AND EDDY CURRENT INSPECTIONS AT S-4R, BS
908 TO BS 1016
1. Remove and keep interior equipment at S-4R from BS 908 to BS 1016. Refer to the applicable
AMM reference below as an accepted procedure.
737-300/-400/-500 AMM SubjectEquipment
737-300/400/500 AMM 25-31-31Galley No. 3
737-300/400/500 AMM 25-40-01Lavatory
737-300/400/500 AMM 25-21-45Sculptured Ceiling Panels
737-300/400/500 AMM 25-21-71Lowered Ceiling Panels
737-300/400/500 AMM 25-21-39Sidewall and Ceiling Insulation
737-300/400/500 AMM 25-24-31Overhead Stowage Bins
737-300/400/500 AMM 25-23-61Passenger Service Units
737-300/400/500 AMM 21-23-25Overhead Air Distribution Duct
2. Do internal detailed and eddy current inspections for cracks in the lower skin at the lap joint lower
fastener row at stringer S-4R from BS 908 to BS 1016 in accordance with FIGURE 7 inspection
zones.
3. Do internal detailed and eddy current inspections for cracks in the lower skin at the lap joint lower
fastener row at S-4R in accordance with FIGURE 2.
a. At locations where the stringer channel prevents the inspection probe from scanning 360
degrees around the fastener formed tail, do an internal eddy current inspection for cracks in
the lower skin in accordance with FIGURE 2, View A-A.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: April 04, 2011
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BOEING SERVICE BULLETIN 737-53A1319
ALERTALERT

### Page 39

NOTE: Inspection procedures 737 NDT Manual Part 6, 53-30-12 and 737 NDT Manual Part
6, 53-30-16 show limited effectivity. The inspections applicable to the lower skin at
the lap joint lower fastener row at stringer S-4R in these procedures are applicable
to the full effectivity in this service bulletin.
4. Install kept interior equipment at the inspection body station locations. Refer to the applicable AMM
reference below as an accepted procedure.
737-300/-400/-500 AMM SubjectEquipment
737-300/400/500 AMM 25-31-31Galley No. 3
737-300/400/500 AMM 25-40-01Lavatory
737-300/400/500 AMM 25-21-45Sculptured Ceiling Panels
737-300/400/500 AMM 25-21-71Lowered Ceiling Panels
737-300/400/500 AMM 25-21-39Sidewall and Ceiling Insulation
737-300/400/500 AMM 25-24-31Overhead Stowage Bins
737-300/400/500 AMM 25-23-61Passenger Service Units
737-300/400/500 AMM 21-23-25Overhead Air Distribution Duct
5. Put the airplane back to a serviceable condition.
Group 2-3, 5, 7:
PART 4: (OPTION 1) EXTERNAL EDDY CURRENT INSPECTION AT S-4R, BS 908 TO BS 1016
1. Do the external eddy current inspection for cracks in the lower skin lap joint lower fastener row at
stringer S-4R from BS 908 to BS 1016 in accordance with FIGURE 7 inspection zones.
2. Do the external eddy current inspection for cracks along the centerline of the lower skin at the lap
joint lower fastener row at stringer S-4R from BS 908 to BS 1016 in accordance with FIGURE 1.
3. Optional. Airplanes with any crack indication when external eddy current inspections are
accomplished, do internal eddy current inspections at crack indication in accordance with FIGURE
3 to confirm crack indications.
4. Put the airplane back to a serviceable condition.
Group 2-3, 5, 7:
PART 4: (OPTION 2) INTERNAL DETAILED AND EDDY CURRENT INSPECTIONS AT S-4R, BS
908 TO BS 1016
1. Remove and keep interior equipment at S-4R from BS 908 to BS 1016. Refer to the applicable
AMM reference below as an accepted procedure.
737-300/-400/-500 AMM SubjectEquipment
737-300/400/500 AMM 25-31-31Galley No. 3
737-300/400/500 AMM 25-40-01Lavatory
737-300/400/500 AMM 25-21-45Sculptured Ceiling Panels
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
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ALERTALERT

### Page 40

737-300/-400/-500 AMM SubjectEquipment
737-300/400/500 AMM 25-21-71Lowered Ceiling Panels
737-300/400/500 AMM 25-21-39Sidewall and Ceiling Insulation
737-300/400/500 AMM 25-24-31Overhead Stowage Bins
737-300/400/500 AMM 25-23-61Passenger Service Units
737-300/400/500 AMM 21-23-25Overhead Air Distribution Duct
2. Do internal detailed and eddy current inspections for cracks in the lower skin at the lap joint lower
fastener row at stringer S-4R from BS 908 to BS 1016 in accordance with FIGURE 7 inspection
zones.
3. Do internal detailed and eddy current inspections for cracks in the lower skin at the lap joint lower
fastener row at S-4R in accordance with FIGURE 2.
a. At locations where the stringer channel prevents the inspection probe from scanning 360
degrees around the fastener formed tail, do an internal eddy current inspection for cracks in
the lower skin in accordance with FIGURE 2, View A-A.
NOTE: Inspection procedures 737 NDT Manual Part 6, 53-30-12 and 737 NDT Manual Part
6, 53-30-16 show limited effectivity. The inspections applicable to the lower skin at
the lap joint lower fastener row at stringer S-4R in these procedures are applicable
to the full effectivity in this service bulletin.
4. Install kept interior equipment at the inspection body station locations. Refer to the applicable AMM
reference below as an accepted procedure.
737-300/-400/-500 AMM SubjectEquipment
737-300/400/500 AMM 25-31-31Galley No. 3
737-300/400/500 AMM 25-40-01Lavatory
737-300/400/500 AMM 25-21-45Sculptured Ceiling Panels
737-300/400/500 AMM 25-21-71Lowered Ceiling Panels
737-300/400/500 AMM 25-21-39Sidewall and Ceiling Insulation
737-300/400/500 AMM 25-24-31Overhead Stowage Bins
737-300/400/500 AMM 25-23-61Passenger Service Units
737-300/400/500 AMM 21-23-25Overhead Air Distribution Duct
5. Put the airplane back to a serviceable condition.
Group 1, 4, 6:
PART 5: INTERNAL GENERAL VISUAL INSPECTION OF LOWER SKIN PANEL AT S-4R, BS 908
TO BS 1016
1. Remove and keep interior equipment at S-4R from BS 908 to BS 1016. Refer to the applicable
AMM reference below as an accepted procedure.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: April 04, 2011
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ALERTALERT

### Page 41

737-300/-400/-500 AMM SubjectEquipment
737-300/400/500 AMM 25-31-31Galley No. 3
737-300/400/500 AMM 25-40-01Lavatory
737-300/400/500 AMM 25-21-45Sculptured Ceiling Panels
737-300/400/500 AMM 25-21-71Lowered Ceiling Panels
737-300/400/500 AMM 25-21-39Sidewall and Ceiling Insulation
737-300/400/500 AMM 25-24-31Overhead Stowage Bins
737-300/400/500 AMM 25-23-61Passenger Service Units
737-300/400/500 AMM 21-23-25Overhead Air Distribution Duct
2. Do an internal general visual inspection of the lower skin panel at S-4R, from BS 908 to BS 1016
for open or closed pockets adjacent to the S-4R lap joint in accordance with FIGURE 7 inspection
zones.
3. Do an internal general visual inspection of the lower skin panel at S-4R, from BS 908 to BS 1016
for open or closed pockets adjacent to the S-4R lap joint in accordance with FIGURE 8.
4. Install kept interior equipment at the inspection body station locations. Refer to the applicable AMM
reference below as an accepted procedure.
737-300/-400/-500 AMM SubjectEquipment
737-300/400/500 AMM 25-31-31Galley No. 3
737-300/400/500 AMM 25-40-01Lavatory
737-300/400/500 AMM 25-21-45Sculptured Ceiling Panels
737-300/400/500 AMM 25-21-71Lowered Ceiling Panels
737-300/400/500 AMM 25-21-39Sidewall and Ceiling Insulation
737-300/400/500 AMM 25-24-31Overhead Stowage Bins
737-300/400/500 AMM 25-23-61Passenger Service Units
737-300/400/500 AMM 21-23-25Overhead Air Distribution Duct
5. Put the airplane back to a serviceable condition.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: April 04, 2011
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BOEING SERVICE BULLETIN 737-53A1319
ALERTALERT

### Page 42 (OCR)

BOEING SERVICE BULLETIN 737-53A1319
ALERT  ALERT
STA
1016
STA
908  UPPER SKIN AND DOUBLER
STA
540
S-4R  10000
S-4L
_ S-4L/R
LOWER SKIN
TEAR STRAP
S-ALR C
CRACKS SHOWN IN THE LOWER SKIN
AT THE LOWER ROW OF FASTENERS
TYPICAL LAP JOINT CONFIGURATION  2068143
FIGURE 1: EXTERNAL INSPECTION
(SHEET 1 OF 2)
Original Issue: April 04, 2011
Revision 2 April 04, 2014  PROPRIETARY - Copyright © Unpublished  Export Controlled ECCN: 9E991 - BOEING  Work - See page 1 for details.  737-53A1319  42 of 62

### Page 43

The step numbers shown below agree with the numbers shown in the circle symbols in the figure.
MORE DATAQTYIDENTIFICATIONNAMETASKSTEP
(a)--Crown Lap Joints Lower
Skin
Inspect1
(a) Do an external eddy current inspection for cracks along the centerline of the lap joint lower fastener row
in accordance with 737 NDT Manual Part 6, 53-30-00 Procedure 9.
FIGURE 1: EXTERNAL INSPECTION
(SHEET 2 OF 2)
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
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BOEING SERVICE BULLETIN 737-53A1319
ALERTALERT

### Page 44 (OCR)

BOEING SERVICE BULLETIN 737-53A1319
ALERT  ALERT
STA
1016
727E  STA  STA
908
STA
540
STA
360  0000 0on0ogosoa0000o0oй.
S-4R
S-4L
TEAR STRAP
S-4L/R
CHEM-MILLED
TYPICAL LAP JOINT CONFIGURATION WHERE LOWER
SKIN DOUBLER IS CHEM-MILLED AT THE LAP JOINT
2068124
FIGURE 2: INTERNAL INSPECTION
(SHEET 1 OF 4)
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PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.  44 of 62

### Page 45 (OCR)

BOEING SERVICE BULLETIN 737-53A1319
ALERT  ALERT
TEAR STRAP
NON CHEM-MILLED
S-4L/R
CHEM-MILLED
TEWD
TYPICAL LAP JOINT CONFIGURATION WHERE LOWER
SKIN DOUBLER IS NOT CHEM-MILLED AT THE LAP JOINT
B  2243741
FIGURE 2: INTERNAL INSPECTION
(SHEET 2 OF 4)
Original Issue: April 04, 2011
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PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.  45 of 62

### Page 46

The step numbers shown below agree with the numbers shown in the circle symbols in the figure.
MORE DATAQTYIDENTIFICATIONNAMETASKSTEP
Between tear straps (a) (b)
(e)
--Crown Lap Joints Lower
Skin
Inspect1
At tear straps (a) (c) (e)--Crown Lap Joints Lower
Skin
Inspect2
Where lower skin doubler is
not chem-milled at the lap
joint (a) (d) (e)
--Crown Lap Joints Lower
Skin
Inspect3
(a) Do a Detailed Inspection of the lap joint lower fastener row for cracks.
(b) Do an internal Mid Frequency Eddy Current (MFEC) inspection for cracks in the lap joint lower fastener
row between tear straps in accordance with 737 NDT Manual Part 6, 53-30-16.
(c) Do an internal Low Frequency Eddy Current (LFEC) inspection for cracks in the lap joint lower fastener
row through the tear strap in accordance with 737 NDT Manual Part 6, 53-30-12.
(d) Do an internal Low Frequency Eddy Current (LFEC) inspection for cracks in the lap joint lower fastener
row through the lower doubler in accordance with 737 NDT Manual Part 6, 53-30-12.
FIGURE 2: INTERNAL INSPECTION
(SHEET 3 OF 4)
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ALERTALERT

### Page 47

MORE DATAQTYIDENTIFICATIONNAMETASKSTEP
(e) View A-A provides an alternative inspection method to note (b), (c), or (d) the full 360-degree probe
scanning around the fastener formed tail that is obstructed by the internal structures. View A-A is illustrated
for between tear straps, but the method can be used at tear straps and where the lower skin is not chem-
milled at the lap joint.
FIGURE 2: INTERNAL INSPECTION
(SHEET 4 OF 4)
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ALERTALERT

### Page 48 (OCR)

BOEING SERVICE BULLETIN 737-53A1319
ALERT  ALERT
STA
1016
727E  STA  STA
908
STA
540
STA
360  0000 0on0ogosoa0000o0oй.
S-4R
S-4L
TEAR STRAP
S-4L/R
CHEM-MILLED
TYPICAL LAP JOINT CONFIGURATION WHERE LOWER
SKIN DOUBLER IS CHEM-MILLED AT THE LAP JOINT
2068144
FIGURE 3: CONFIRMING A CRACK INDICATION
(SHEET 1 OF 4)
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Work - See page 1 for details.  48 of 62

### Page 49 (OCR)

BOEING SERVICE BULLETIN 737-53A1319
ALERT  ALERT
TEAR STRAP
NON CHEM-MILLED
S-4L/R
CHEM-MILLED
TEWD
TYPICAL LAP JOINT CONFIGURATION WHERE LOWER
SKIN DOUBLER IS NOT CHEM-MILLED AT THE LAP JOINT
B  2244133
FIGURE 3: CONFIRMING A CRACK INDICATION
(SHEET 2 OF 4)
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### Page 50

The step numbers shown below agree with the numbers shown in the circle symbols in the figure.
MORE DATAQTYIDENTIFICATIONNAMETASKSTEP
Between tear straps (a) (d)--Crown Lap Joints Lower
Skin
Inspect1
At tear straps (b) (d)--Crown Lap Joints Lower
Skin
Inspect2
Where lower skin doubler is
not chem-milled at the lap
joint (c) (d)
--Crown Lap Joints Lower
Skin
Inspect3
(a) If there was a crack indication at this location as a result of the external eddy current inspection: Do an
internal Mid Frequency Eddy Current (MFEC) inspection for cracks in the lap joint lower fastener row be-
tween tear straps in accordance with 737 NDT Manual Part 6, 53-30-16.
(b) If there was a crack indication at this location: Do an internal Low Frequency Eddy Current (LFEC) inspection
for cracks in the lap joint lower fastener row through the tear strap in accordance with 737 NDT Manual
Part 6, 53-30-12.
(c) If there was a crack indication at this location: Do an internal Low Frequency Eddy Current (LFEC) inspection
for cracks in the lap joint lower fastener row through the lower doubler in accordance with 737 NDT Man-
ual Part 6, 53-30-12.
FIGURE 3: CONFIRMING A CRACK INDICATION
(SHEET 3 OF 4)
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737-53A1319Revision 2 April 04, 2014
50 of 62
BOEING SERVICE BULLETIN 737-53A1319
ALERTALERT

### Page 51

MORE DATAQTYIDENTIFICATIONNAMETASKSTEP
(d) View A-A provides an alternative inspection method to note (a), (b), or (c) the full 360-degree probe
scanning around the fastener formed tail that is obstructed by the internal structures. View A-A is illustrated
for between tear straps, but the method can be used at tear straps and where the lower skin is not chem-
milled at the lap joint.
FIGURE 3: CONFIRMING A CRACK INDICATION
(SHEET 4 OF 4)
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
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51 of 62
BOEING SERVICE BULLETIN 737-53A1319
ALERTALERT

### Page 52 (OCR)

BOEING SERVICE BULLETIN 737-53A1319
ALERT  ALERT
THIS FIGURE IS DELETED.
FIGURE 4: FIGURE DELETED AT REVISION 2
(SHEET 1 OF 1)
riginal issue: April 04, 201  evision 2 April 04, 201•  Export Controlled ECCN: 9E991 - BOEING  737-53A1319
PROPRIETARY - Copyright © Unpublished
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### Page 53 (OCR)

BOEING SERVICE BULLETIN 737-53A1319
ALERT  ALERT
This Figure applies only to: Group 1-2, 4-7.
S-4R S-4L
STA
1016
•
STA
908
STA
STA
540
STA
360
STA
259.50  737-300  2068147
FIGURE 5: INSPECTION ZONES
(SHEET 1 OF 3)
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Work - See page 1 for details.  53 of 62

### Page 54 (OCR)

BOEING SERVICE BULLETIN 737-53A1319
ALERT  ALERT
SAR SAL
STA
1016
STA
908
00
•0000.
STA  0000
727
STA
540
0000  •0u.uoo
STA
360
STA
259.50  737-400  2068148
FIGURE 5: INSPECTION ZONES
(SHEET 2 OF 3)
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Work - See page 1 for details.  54 of 62

### Page 55 (OCR)

BOEING SERVICE BULLETIN 737-53A1319
ALERT  ALERT
S-4R S-4L
STA
1016
STA
908
00  0000
•00
STA
360
STA
259.50  737-500  2068149
FIGURE 5: INSPECTION ZONES
(SHEET 3 OF 3)
Original Issue: April 04, 2011
Revision 2 April 04, 2014  PROPRIETARY - Copyright © Unpublished  Export Controlled ECCN: 9E991 - BOEING  737-53A1319
Work - See page 1 for details.  55 of 62

### Page 56 (OCR)

BOEING SERVICE BULLETIN 737-53A1319
ALERT  ALERT
This Figure applies only to: Group 3.
S-4R S-4L
STA
1016
STA
908
o 0 0
STA
727
STA
540
•
O C
STA
360
STA
259.50  737-300  2244119
FIGURE 6: INSPECTION ZONES
(SHEET 1 OF 1)
Original Issue: April 04, 2011
Revision 2 April 04, 2014  Export Controlled ECCN: 9E991 - BOEING  PROPRIETARY - Copyright @ Unpublished  737-53A1319
Work - See page 1 for details.  56 of 62

### Page 57 (OCR)

BOEING SERVICE BULLETIN 737-53A1319
ALERT  ALERT
S-4R  S-4L
STA
1016
STA-
908
•
0 0  o o
ol
STA
727
000
STA
540
0l0
STA
360
STA
259.50  737-300  2293362
FIGURE 7: INSPECTION ZONES
(SHEET 1 OF 3)
Original Issue: April 04, 2011
Revision 2 April 04, 2014  PROPRIETARY - Copyright © Unpublished  Export Controlled ECCN: 9E991 - BOEING  737-53A1319
Work - See page 1 for details.  57 of 62

### Page 58 (OCR)

BOEING SERVICE BULLETIN 737-53A1319
ALERT  ALERT
SAR SAL
STA
1016
STA
908
STA  000000000
727
STA
540
0o•.•....00
STA
360
STA
259.50
737-400  2293366
FIGURE 7: INSPECTION ZONES
(SHEET 2 OF 3)
Original Issue: April 04, 2011
Revision 2 April 04, 2014  Export Controlled ECCN: 9E991 - BOEING  PROPRIETARY - Copyright @ Unpublished  737-53A1319
Work - See page 1 for details.  58 of 62

### Page 59 (OCR)

BOEING SERVICE BULLETIN 737-53A1319
ALERT  ALERT
S-4R S-4L
STA
1016
STA
908
SIA
727
STA
J  000
STA
360
STA
259.50  737-500  2293368
FIGURE 7: INSPECTION ZONES
(SHEET 3 OF 3)
Original Issue: April 04, 2011
Revision 2 April 04, 2014  PROPRIETARY - Copyright © Unpublished  Export Controlled ECCN: 9E991 - BOEING  737-53A1319
Work - See page 1 for details.  59 of 62

### Page 60 (OCR)

BOEING SERVICE BULLETIN 737-53A1319
ALERT  ALERT
This Figure applies only to: Group 1, 4, 6.
STA
1016
STA
908
AND
70
S-4R
STA
908
TEAR STRAP  STA
927
*S-3R
S-AR
CHEM-MILLED  WITH OPEN  VaNo
POCKETS
TYPICAL LAP JOINT CONFIGURATION WHERE LOWER
SKIN DOUBLER IS CHEM-MILLED AT THE LAP JOINT
2265295
FIGURE 8: INTERNAL GENERAL VISUAL INSPECTION - LOWER SKIN PANEL AT S-4R, BS 908 TO BS
1016
(SHEET 1 OF 3)
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