Commercial 

Airplanes 737

Service Bulletin

ALERT

Number: 737-57A1326

Original Issue: September 22, 2015

ATA System: 5711

SUBJECT: WING - Wing Spars - Inspection of Upper Wing Skin at Rear Spar, Wing Buttock Line

157

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.

ECCN: 9E991

BOEING PROPRIETARY, CONFIDENTIAL AND/OR TRADE SECRET

Copyright © 2015 Boeing.

Unpublished Work. All Rights Reserved.

Treatment of this document and its content is governed by contract with Boeing. Rights to use this document

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Boeing Company.

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BOEING SERVICE BULLETIN 737-57A1326

ALERT ALERT

BLANK PAGE
Table of Contents

Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

1. PLANNING INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

A. Effectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

1. Airplanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

B. Concurrent Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

C. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

E. Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

H. Weight and Balance Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

1. Existing Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

2. Data Supplied with this Service Bulletin: . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

3. Installation Drawings Used in the Preparation of this Service Bulletin: . . . . . . . . . . . 26

K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

M. Software Accomplishment Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

2. MATERIAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

A. Material - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

C. Parts Necessary for Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

1. Kits/Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

2. Parts and Materials Supplied by the Operator . . . . . . . . . . . . . . . . . . . . . . . . 29

3. Parts Modified and Reidentified . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

4. Parts Removed and Not Replaced . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

D. Parts Necessary to Change Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

E. Special Tooling - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

F. Special Tooling Necessary to do this Service Bulletin . . . . . . . . . . . . . . . . . . . . . . . 29

3. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

B. WORK INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

FIGURE 1: HFEC INSPECTION OF INSPAR UPPER SKIN AT REAR SPAR, WBL 157 [Group 1,

Configuration 2, 5] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

FIGURE 2: HFEC INSPECTION OF INSPAR UPPER SKIN AND REPAIR DOUBLER AT REAR SPAR,

WBL 157 [Group 1, Configuration 3, 6] . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

FIGURE 3: HFEC AND LFEC INSPECTION OF INSPAR UPPER SKIN, REPAIR DOUBLER, AND REPAIR

TRIPLER AT REAR SPAR, WBL 157 [Group 1, Configuration 4, 7] . . . . . . . . . . . . . 38

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BOEING SERVICE BULLETIN 737-57A1326

ALERT ALERT
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BOEING SERVICE BULLETIN 737-57A1326

ALERT ALERT

BLANK PAGE
Commercial 

Airplanes 737

Service Bulletin

ALERT

Summary Number: 737-57A1326

Original Issue: September 22, 2015

ATA System: 5711

SUBJECT: WING - Wing Spars - Inspection of Upper Wing Skin at Rear Spar, Wing Buttock Line

157

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

For airplanes that have not been inspected using the High Frequency Eddy Current (HFEC) open hole inspection

in accordance with Service Bulletin (SB) 737-57-1318, this SB gives instructions to do inspections for any crack

in the inspar upper skin area near the rear spar at Wing Buttock Line (WBL) 157 until SB 737-57-1318 is

accomplished. For an airplane that has not been inspected using the HFEC open hole inspection in accordance

with SB 737-57-1318, if the inspections in this service bulletin are not done, a crack in the upper chord and skin

can grow undetected and result in the inability of the structure to carry limit load or result in a fuel leak and could

prevent a continued safe flight and landing.

While doing SB 737-57-1318, an operator discovered a crack in the inspar upper skin at WBL 157 just forward

of the rear spar on the right wing. The crack measured 2.375 inches long. Two additional cracks were found in

the skin at two holes common to the rear spar in the same area. Subsequent inspections per SB 737-57-1318

revealed that the rear spar upper chord was almost completely severed. Further inspections per SB 737-57-1318

revealed that the left rear spar upper chord was completely severed. Web cracks were also discovered on both

wings.

The airplane was a 737-300 with 64,095 flight hours and 51,548 flight cycles. The airplane was within the 4,500

flight cycle grace period allowed by SB 737-57-1318. The inspections in this SB will ensure there is no undetected

crack in the inspar upper skin area near the rear spar at WBL 157 prior to the accomplishment of the inspections

required by SB 737-57-1318.

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737-57A1326

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This table is provided to operators for planning purposes only. Refer to the applicable sections for more

information.

Planning Data Affected Reference

Spares Affected No Paragraph 1.A.2., Spares Affected

Paragraph 1.E., Compliance and Paragraph

1.F., Approval

AD Related Yes

Weight and Balance Change No Paragraph 1.H., Weight and Balance Changes

Electrical Load Changed No Paragraph 1.I., Electrical Load Data

Publications Affected No Paragraph 1.K., Publications Affected

Airplane Flight Operations Affected (Flight Crew No Paragraph 1.K., Publications Affected

Operations Manual and/or FAA Approved Airplane Flight Manual)

Kits/Parts Required No Paragraph 2.C.1., Kits/Parts

Paragraph 2.C.2., Parts and Materials Supplied

by the Operator

Operator Supplied Parts/Material No

Paragraph 2.F., Special Tooling Necessary to

do this Service Bulletin

Special Tooling Required No

ACTION

Airplanes that have not been inspected using the HFEC open hole inspection in accordance with SB 737-57-1318,

do an eddy current inspection for any crack in the inspar upper skin area near the rear spar at WBL 157. If a

repair has been installed, do an eddy current inspection for any crack in the repair parts. If any crack is found,

do the HFEC open hole inspection in accordance with SB 737-57-1318 and contact Boeing for repair instructions

and do the repair.

EFFECTIVITY

All 737-100, 737-200, 737-200C, 737-300, 737-400, and 737-500 airplanes. Refer to Paragraph 1.A.1., Airplanes,

for the list of affected airplanes.

COMPLIANCE

The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to this service

bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin

mandatory.

Refer to Paragraph 1.E., Compliance.

INDUSTRY SUPPORT INFORMATION

At the time of release of this service bulletin, warranty remedies have not been determined. A subsequent

revision or Information Notice will address the warranty remedies available, if any.

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BOEING SERVICE BULLETIN 737-57A1326

ALERT ALERT
MANPOWER

Refer to Paragraph 1.G., Manpower.

MATERIAL INFORMATION

None.

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BOEING SERVICE BULLETIN 737-57A1326

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BOEING SERVICE BULLETIN 737-57A1326

ALERT ALERT
Commercial 

Airplanes 737

Service Bulletin

ALERT

Number: 737-57A1326

Original Issue: September 22, 2015

ATA System: 5711

SUBJECT: WING - Wing Spars - Inspection of Upper Wing Skin at Rear Spar, Wing Buttock Line

157

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 applicable to line numbers 1 to 3132 in 1 Group. The Variable Numbers

and Group Information for the applicable airplanes is given below.

Refer to Service Bulletin Index D6-19567 Part 3 for Airplane Variable Number, Line Number, and

Serial Number data.

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737-57A1326

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GROUP CONFIGURATION DESCRIPTION

737-100, 737-200, 737-200C, 737-300, 737-400, and 737-500

airplanes Line Numbers 1 to 3132.

1 -

Airplanes that have been inspected using the High Frequency Eddy

Current (HFEC) open hole inspection in accordance with Service

Bulletin 737-57-1318.

1

Airplanes that have been inspected using only the HFEC surface

inspection in accordance with Service Bulletin 737-57-1318 and do

not have a repair doubler or repair tripler in the inspection area.

2

Airplanes that have been inspected using only the HFEC surface

inspection in accordance with Service Bulletin 737-57-1318 and have

a repair doubler in the inspection area common to the rear spar chord

fasteners that extends to the aft edge of the inspar skin similar to

repair drawing 65C30105.

3

Airplanes that have been inspected using only the HFEC surface

inspection in accordance with Service Bulletin 737-57-1318 and have

a repair tripler and a repair doubler in the inspection area common

to the rear spar chord fasteners that extends forward to the adjacent

stringer similar to repair drawing 65C30113.

4

Airplanes that have not been inspected in accordance with Service

Bulletin 737-57-1318 and do not have a repair doubler or repair tripler

in the inspection area.

5

Airplanes that have not been inspected in accordance with Service

Bulletin 737-57-1318 and have a repair doubler in the inspection area

common to the rear spar chord fasteners that extends to the aft edge

of the inspar skin similar to repair drawing 65C30105.

6

Airplanes that have not been inspected in accordance with Service

Bulletin 737-57-1318 and have a repair tripler and a repair doubler

in the inspection area common to the rear spar chord fasteners that

extends forward to the adjacent stringer similar to repair drawing

65C30113.

7

Airplane Models:

737-100, 737-200, 737-200C, 737-300, 737-400, 737-500

Variable Number Group

PA001 - PA022 1

PA099 1

PA231 - PA232 1

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BOEING SERVICE BULLETIN 737-57A1326

ALERT ALERT
Variable Number Group

PC001 - PC005 1

PG001 - PG075 1

PG199 1

PG201 - PG230 1

PG251 - PG255 1

PG271 - PG279 1

PG301 - PG314 1

PG331 - PG332 1

PG351 - PG356 1

PG375 1

PG401 - PG403 1

PG431 - PG442 1

PG471 - PG475 1

PG501 - PG505 1

PG571 - PG586 1

PG621 - PG630 1

PG651 - PG652 1

PG701 - PG705 1

PH001 1

PH011 - PH013 1

PH021 - PH024 1

PH701 - PH715 1

PH731 - PH732 1

PH741 - PH743 1

PJ001 - PJ009 1

PJ031 - PJ032 1

PJ071 - PJ072 1

PJ101 - PJ119 1

PJ201 - PJ219 1

PJ301 - PJ302 1

PJ551 - PJ561 1

PJ601 - PJ615 1

PJ811 1

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BOEING SERVICE BULLETIN 737-57A1326

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Variable Number Group

PJ816 - PJ817 1

PK026 - PK029 1

PK041 - PK053 1

PK061 - PK070 1

PK081 - PK082 1

PK091 - PK099 1

PK101 - PK103 1

PK111 - PK120 1

PK141 - PK146 1

PK201 - PK204 1

PK211 - PK223 1

PK231 - PK241 1

PK251 - PK258 1

PK271 - PK274 1

PK281 - PK289 1

PK291 1

PK301 - PK318 1

PK341 1

PK351 - PK361 1

PK391 1

PK431 - PK433 1

PK451 - PK452 1

PK461 - PK469 1

PK495 1

PK501 - PK504 1

PK511 - PK515 1

PK519 1

PK521 - PK528 1

PK541 - PK565 1

PK581 1

PK591 - PK599 1

PK601 - PK617 1

PK621 - PK637 1

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BOEING SERVICE BULLETIN 737-57A1326

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Variable Number Group

PK641 - PK642 1

PK661 - PK666 1

PK671 - PK681 1

PK691 - PK697 1

PK711 - PK716 1

PK731 - PK765 1

PK771 - PK779 1

PK801 - PK804 1

PK819 - PK827 1

PK830 1

PK861 - PK863 1

PK871 - PK874 1

PK881 - PK884 1

PK901 - PK938 1

PK971 - PK974 1

PL001 - PL028 1

PL061 1

PL081 1

PL101 - PL113 1

PL151 1

PL171 - PL172 1

PL201 - PL203 1

PL221 1

PL401 - PL417 1

PL421 1

PL441 1

PL451 - PL456 1

PL471 1

PL491 1

PL501 - PL506 1

PL551 - PL562 1

PL581 1

PL601 - PL603 1

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BOEING SERVICE BULLETIN 737-57A1326

ALERT ALERT
Variable Number Group

PL611 1

PL621 - PL626 1

PL631 - PL632 1

PL711 - PL712 1

PL716 - PL747 1

PL756 1

PL758 1

PL761 - PL770 1

PL781 - PL788 1

PL793 1

PL801 - PL803 1

PM001 - PM006 1

PM016 - PM017 1

PM021 - PM023 1

PM051 - PM066 1

PM101 - PM119 1

PM141 - PM142 1

PM171 1

PM181 1

PM251 - PM255 1

PM281 - PM283 1

PM381 - PM399 1

PM401 - PM417 1

PM541 - PM564 1

PN001 - PN002 1

PN021 - PN043 1

PN081 - PN086 1

PN101 - PN117 1

PN131 - PN163 1

PN401 - PN420 1

PN431 - PN433 1

PN451 - PN456 1

PN471 - PN474 1

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BOEING SERVICE BULLETIN 737-57A1326

ALERT ALERT
Variable Number Group

PN481 1

PN491 - PN493 1

PN501 - PN502 1

PN511 - PN512 1

PN521 1

PP001 - PP054 1

PP101 - PP169 1

PP181 - PP199 1

PP201 - PP205 1

PP221 1

PP231 - PP243 1

PP281 - PP286 1

PP301 - PP305 1

PP351 - PP353 1

PP376 - PP384 1

PP391 - PP393 1

PP401 - PP440 1

PP471 - PP475 1

PP501 - PP522 1

PP631 - PP634 1

PP651 - PP652 1

PP671 - PP699 1

PP701 - PP733 1

PP771 - PP779 1

PP801 - PP808 1

PP821 - PP827 1

PP831 - PP848 1

PP851 - PP852 1

PP861 - PP877 1

PP891 - PP899 1

PP901 - PP936 1

PP946 - PP948 1

PP951 - PP952 1

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Variable Number Group

PP961 - PP967 1

PP981 - PP991 1

PP993 1

PQ001 - PQ016 1

PQ026 - PQ041 1

PQ051 - PQ092 1

PQ101 - PQ199 1

PQ201 - PQ202 1

PQ221 - PQ237 1

PQ241 - PQ243 1

PQ251 - PQ267 1

PQ281 - PQ299 1

PQ301 - PQ307 1

PQ331 - PQ332 1

PQ341 - PQ348 1

PQ361 - PQ373 1

PQ391 - PQ395 1

PQ401 - PQ418 1

PQ421 1

PQ431 - PQ438 1

PQ447 - PQ448 1

PQ451 1

PQ454 1

PQ471 - PQ475 1

PQ479 - PQ481 1

PQ486 - PQ487 1

PQ491 - PQ493 1

PQ771 - PQ772 1

PQ791 - PQ793 1

PQ801 - PQ805 1

PQ931 - PQ935 1

PQ951 1

PQ971 - PQ997 1

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Variable Number Group

PR001 - PR017 1

PR021 - PR034 1

PR041 - PR045 1

PR061 - PR072 1

PR077 - PR082 1

PR091 - PR092 1

PR096 1

PR101 1

PR121 - PR122 1

PR131 - PR132 1

PR141 - PR143 1

PR161 - PR172 1

PR181 1

PS601 - PS631 1

PS636 - PS638 1

PS641 - PS644 1

PS651 - PS657 1

PS666 - PS669 1

PS691 - PS692 1

PS701 - PS706 1

PS751 - PS799 1

PS811 1

PS836 - PS837 1

PS841 - PS846 1

PS851 - PS852 1

PS856 1

PS861 - PS863 1

PS866 - PS868 1

PS871 - PS874 1

PS896 - PS897 1

PS901 - PS941 1

PS956 - PS957 1

PS961 - PS963 1

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BOEING SERVICE BULLETIN 737-57A1326

ALERT ALERT
Variable Number Group

PS971 - PS978 1

PT001 - PT015 1

PT021 - PT031 1

PT041 - PT064 1

PT101 - PT105 1

PT121 - PT138 1

PT146 - PT148 1

PT161 - PT170 1

PT181 - PT188 1

PT211 - PT220 1

PT295 1

PT301 - PT309 1

PT331 - PT360 1

PT381 - PT399 1

PT401 - PT438 1

PT501 - PT517 1

PT561 - PT565 1

PT581 - PT586 1

PT611 - PT621 1

PT641 - PT644 1

PT651 - PT656 1

PT671 - PT672 1

PT681 - PT685 1

PT701 - PT703 1

PT716 - PT717 1

PT721 - PT725 1

PT801 - PT834 1

PT851 - PT854 1

PT871 - PT886 1

PT901 - PT930 1

PT971 - PT973 1

PT981 - PT985 1

PT996 1

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Variable Number Group

PU001 - PU025 1

PU301 1

PU311 - PU313 1

PV001 - PV055 1

PV201 - PV209 1

PV226 - PV229 1

PV231 - PV237 1

PV271 - PV272 1

PV281 - PV287 1

PV296 1

PV301 - PV302 1

PV351 1

PV356 - PV357 1

PW001 - PW054 1

PW061 - PW068 1

PW072 1

PW086 - PW088 1

PW091 - PW094 1

PW101 - PW102 1

PW106 1

PW111 - PW120 1

PW156 - PW157 1

PW161 - PW171 1

PW201 - PW252 1

PW261 - PW268 1

PW271 - PW276 1

PW278 1

PW281 - PW293 1

PW296 1

PW301 - PW327 1

PW401 - PW408 1

PW411 - PW418 1

PW421 - PW424 1

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Variable Number Group

PW431 - PW435 1

PW441 - PW450 1

PW461 - PW467 1

PW501 - PW504 1

PW511 - PW522 1

PW524 - PW550 1

PW556 - PW557 1

PW561 - PW564 1

PW571 - PW576 1

PW591 - PW596 1

PW611 - PW622 1

PW631 - PW637 1

PW661 - PW662 1

PW681 - PW683 1

PW701 - PW702 1

PW711 - PW717 1

PW741 - PW742 1

PW761 1

PW771 1

PW831 1

PW851 - PW856 1

PX071 1

PX701 1

PY001 - PY008 1

PY021 - PY022 1

PY031 1

PY036 - PY037 1

PY046 - PY048 1

PY051 - PY053 1

PY056 - PY057 1

PY101 - PY103 1

PY111 - PY113 1

PY131 - PY135 1

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Variable Number Group

PY141 - PY143 1

PY151 - PY154 1

PY156 - PY157 1

PY161 - PY162 1

PY166 1

PY191 1

PY201 1

PY221 - PY222 1

PY231 1

PY241 - PY244 1

PY270 - PY275 1

PY281 1

PY286 1

PY301 - PY304 1

PY321 - PY323 1

PY341 - PY346 1

PY361 - PY362 1

PY381 1

PY401 1

PY409 - PY411 1

PY421 - PY422 1

PY441 1

PY451 1

PY461 - PY463 1

PY591 - PY595 1

PY611 - PY612 1

PY621 1

PY631 1

PY651 1

PY671 - PY672 1

PY721 1

PY741 1

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2. Spares Affected

None.

B. Concurrent Requirements

None.

C. Reason

For airplanes that have not been inspected using the High Frequency Eddy Current (HFEC) open hole

inspection in accordance with Service Bulletin (SB) 737-57-1318, this SB gives instructions to do

inspections for any crack in the inspar upper skin area near the rear spar at Wing Buttock Line (WBL)

157 until SB 737-57-1318 is accomplished. For an airplane that has not been inspected using the HFEC

open hole inspection in accordance with SB 737-57-1318, if the inspections in this service bulletin are

not done, a crack in the upper chord and skin can grow undetected and result in the inability of the

structure to carry limit load or result in a fuel leak and could prevent a continued safe flight and landing.

While doing SB 737-57-1318, an operator discovered a crack in the inspar upper skin at WBL 157 just

forward of the rear spar on the right wing. The crack measured 2.375 inches long. Two additional cracks

were found in the skin at two holes common to the rear spar in the same area. Subsequent inspections

per SB 737-57-1318 revealed that the rear spar upper chord was almost completely severed. Further

inspections per SB 737-57-1318 revealed that the left rear spar upper chord was completely severed.

Web cracks were also discovered on both wings.

The airplane was a 737-300 with 64,095 flight hours and 51,548 flight cycles. The airplane was within

the 4,500 flight cycle grace period allowed by SB 737-57-1318. The inspections in this SB will ensure

there is no undetected crack in the inspar upper skin area near the rear spar at WBL 157 prior to the

accomplishment of the inspections required by SB 737-57-1318.

D. Description

Airplanes that have not been inspected using the HFEC open hole inspection in accordance with SB

737-57-1318, do an eddy current inspection for any crack in the inspar upper skin area near the rear

spar at WBL 157. If a repair has been installed, do an eddy current inspection for any crack in the repair

parts. If any crack is found, do the HFEC open hole inspection in accordance with SB 737-57-1318

and contact Boeing for repair instructions and do the repair.

The work in this service bulletin is done in the maintenance zone(s) given below.

Group 1:

Affected Maintenance Zones

Model Zone

737-100, 737-200, 737-200C 3-5, 4-5

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Group 1:

Affected Maintenance Zones

Model Zone

737-300, 737-400, 737-500 305, 405

E. Compliance

The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to

this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this

service bulletin mandatory.

Group 1, Configuration 1:

No action required.

Group 1, Configuration 2-7:

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.

Group 1, Configuration 2-7:

Do the required actions in accordance with Paragraph 3. Accomplishment Instructions.

NOTE: "Repair Parts" are defined as any combination of a repair doubler and repair tripler.

NOTE: Boeing endorses the new FAA rules related to Limit of Validity (LOV) and recommends

immediate and permanent removal from service of any airplane upon reaching the LOV,

whether or not it is operated under FAA jurisdiction. As such, Boeing no longer provides

maintenance instructions for airplanes that have accumulated flight cycles beyond the LOV.

Line numbers 1-291 have accumulated flight cycles beyond the LOV of the airplane. 14 Code

of Federal Regulations (CFR) Part 121.1115 and 129.115 prohibit operation of an airplane

beyond its LOV.

Group 1, Configuration 2-4:

Table 1: Eddy Current Inspection of Inspar Upper Skin Common to the Rear Spar at WBL 157

Repeat Interval

(Not to Exceed)

Compliance Time (Whichever

Occurs Later)

Condition Action

Within 500 flight -

cycles after the

Original Issue

date of this service bulletin.

Before 30,000

total flight cycles.

Do PART 1: EDDY CURRENT INSPECTION for

any crack in the inspar

upper skin and, if installed, the repair parts.

All Airplanes.

No further action re- - - -

quired.

CONDITION 1: NO

CRACK FOUND

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Group 1, Configuration 2-4:

Table 1: Eddy Current Inspection of Inspar Upper Skin Common to the Rear Spar at WBL 157

Repeat Interval

(Not to Exceed)

Compliance Time (Whichever

Occurs Later)

Condition Action

Before further -

flight.

ACTION 1: Do the HFEC

open hole inspection in

accordance with SB 737-

57-1318.

CONDITION 2: ANY

CRACK FOUND

Before further - -

flight.

ACTION 2: Contact Boeing for repair instructions

and do the repair.

Group 1, Configuration 5-7:

Table 2: Eddy Current Inspection of Inspar Upper Skin Common to the Rear Spar at WBL 157

Repeat Interval

(Not to Exceed)

Compliance Time (Whichever

Occurs Later)

Condition Action

Within 500 flight -

cycles after the

Original Issue

date of this service bulletin.

Before 30,000

total flight cycles.

Do PART 1: EDDY CURRENT INSPECTION for

any crack in the inspar

upper skin and, if installed, the repair parts.

All Airplanes with 40,000

total flight cycles or less as

of the Original Issue date

of this service bulletin.

Within 30 days -

after the Original Issue date of

this service bulletin.

Do PART 1: EDDY CUR- -

RENT INSPECTION, for

any crack in the inspar

upper skin and, if installed, the repair parts.

All Airplanes with more

than 40,000 total flight cycles as of the Original Issue date of this service

bulletin.

500 flight cycles.

(a)

Repeat PART 1: EDDY - -

CURRENT INSPECTION, for any crack in the

inspar upper skin and, if

installed, the repair parts.

CONDITION 1: NO

CRACK FOUND

Before further -

flight.

ACTION 1: Do the HFEC

open hole inspection in

accordance with SB 737-

57-1318. (b)

CONDITION 2: ANY

CRACK FOUND

Before further - -

flight.

ACTION 2: Contact Boeing for repair instructions

and do the repair.

(a) Accomplishment of any inspection in accordance with SB 737-57-1318 terminates the repeat inspections

in this SB.

(b) Accomplishment of the HFEC open hole inspection in accordance with SB 737-57-1318 terminates the

repeat inspections in this SB.

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F. Approval

This service bulletin was examined by the Federal Aviation Administration (FAA). The changes specified

in this service bulletin comply with the applicable regulations and are FAA approved, as well as European

Aviation Safety Agency (EASA)/Joint Aviation Authorities (JAA) approved for all EASA/JAA approved

airplanes listed in the service bulletin effectivity. This service bulletin and its approval were based on

the airplane in its original Boeing delivery configuration or as modified by other approved Boeing

changes.

If an airplane has a non-Boeing modification or repair that affects a component or system also affected

by this service bulletin, the operator is responsible for obtaining appropriate regulatory agency approval

before incorporating this service bulletin.

G. Manpower

The table below shows an estimate of the task hours necessary to do this work 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, Configuration 2, 5:

Task Number of Persons Task Hours Elapsed Hours

Figure 1 1 1.0 1.0

TOTAL FOR EACH AIRPLANE 1.0 1.0

Group 1, Configuration 3, 6:

Task Number of Persons Task Hours Elapsed Hours

Figure 2 1 1.0 1.0

TOTAL FOR EACH AIRPLANE 1.0 1.0

Group 1, Configuration 4, 7:

Task Number of Persons Task Hours Elapsed Hours

Figure 3 1 1.0 1.0

TOTAL FOR EACH AIRPLANE 1.0 1.0

H. Weight and Balance Changes

None.

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I. Electrical Load Data

Not changed.

J. References

1. Existing Data:

a. Boeing Service Bulletin 737-57-1318

b. Boeing Service Letter 737-SL-51-042

c. Service Bulletin Index D6-19567

d. 737 Non-Destructive Testing (NDT) Manual Part 6, 51-00-00 Procedure 4 or Procedure 23,

Part 6, 51-00-26

2. Data Supplied with this Service Bulletin:

a. Drawings:

Drawing No Title Sheet DCN/REV ADCN

UPPER REAR SPAR CHORD REINFORCE- DWG - -

MENT - RSS 224

65C30105

SKIN REPAIR INSTL - UPPER, WBL 157.0, DWG - -

REAR SPAR TO S-4

65C30113

3. Installation Drawings Used in the Preparation of this Service Bulletin:

Drawing Number Title

65C25204 WING SKIN

65-45321 REAR SPAR INSTALLATION - WING

65C30105 UPPER REAR SPAR CHORD REINFORCEMENT - RSS 224

65C30113 SKIN REPAIR INSTL - UPPER, WBL 157.0, REAR SPAR TO S-4

The table above lists applicable drawings used to prepare this service bulletin. The drawings are

not necessary to make the specified changes, and are not supplied with this service bulletin. The

drawings may not be applicable to all airplane configurations or operators.

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ALERT ALERT
K. Publications Affected

1. Publications:

None.

2. Damage Tolerance Based Structural Inspections:

Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue

Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the

Maintenance Program. This service bulletin affects FCS but no new DTIs are necessary.

L. Interchangeability and Intermixability of Parts

Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts.

M. Software Accomplishment Summary

Not affected.

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ALERT ALERT

BLANK PAGE
2. MATERIAL INFORMATION

A. Material - Price and Availability

None.

B. Industry Support Information

At the time of release of this service bulletin, warranty remedies have not been determined. A subsequent

revision or Information Notice will address the warranty remedies available, if any.

C. Parts Necessary for Each Airplane

1. Kits/Parts

None.

2. Parts and Materials Supplied by the Operator

No special parts or materials are necessary to do the change in this service bulletin. But, parts

and materials in the manuals given in Paragraph 1.J., References, can be necessary. Examine

operator part and material supply to make sure all necessary parts and materials are available.

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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ALERT ALERT

BLANK PAGE
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

Aircraft Maintenance Manual (AMM).

— Non-standard torque values for maintenance tasks are included in the

applicable installation step.

4. 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.

5. 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.

6. 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.

7. Use of colors in Figures is based on guidance from the ATA e-Business Program

(ATA) iSpec 2200.

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ALERT ALERT
8. 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.

9. The compliance times for the actions in Paragraph 3.B., WORK INSTRUCTIONS

are in Paragraph 1.E., Compliance.

10. Some steps in the Work Instructions are labeled as Required for Compliance (RC).

If this service bulletin is mandated by an Airworthiness Directive (AD), then the steps

labeled as RC, including sub-steps under an RC step and any figures identified in

an RC step, must be done to comply with the AD. An Alternative Method of

Compliance (AMOC) is required for any deviations to RC steps, including sub-steps

and identified figures. Steps not labeled as RC may be deviated from using accepted

methods in accordance with the operator's maintenance or inspection program without

obtaining approval of an AMOC. This is provided that the RC steps, including

sub-steps and identified figures, can still be done as specified, and the airplane can

be put back in an airworthy condition.

11. "Repair Parts" are defined as any combination of a repair doubler and repair tripler.

B. WORK INSTRUCTIONS

Group 1, Configuration 2-7:

1. RC - Do PART 1: EDDY CURRENT INSPECTION for any crack in the inspar upper skin, and if

installed, the repair parts.

a. CONDITION 1: NO CRACK FOUND.

(1) Group 1, Configuration 2-4:

No further action required.

(2) Group 1, Configuration 5-7:

Repeat PART 1: EDDY CURRENT INSPECTION for any crack in the inspar upper skin,

and if installed, the repair parts.

Group 1, Configuration 5-7:

NOTE: Accomplishment of any inspection in accordance with SB 737-57-1318 terminates

the repeat inspections in this SB.

b. CONDITION 2: ANY CRACK FOUND.

(1) ACTION 1: Do the High Frequency Eddy Current (HFEC) open hole inspection in

accordance with Service Bulletin (SB) 737-57-1318.

(2) ACTION 2: Contact Boeing for repair instructions and do the repair.

Group 1, Configuration 5-7:

NOTE: Accomplishment of the HFEC open hole inspection in accordance with SB

737-57-1318 terminates the repeat inspections in this SB.

2. Put the airplane back to a serviceable condition.

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PART 1: EDDY CURRENT INSPECTION

1.

Group 1, Configuration 2, 5:

Do the inspections in accordance with FIGURE 1.

Group 1, Configuration 3, 6:

Do the inspections in accordance with FIGURE 2.

Group 1, Configuration 4, 7:

Do the inspections in accordance with FIGURE 3.

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This Figure applies only to: Group 1, Configuration 2, 5.

FIGURE 1: HFEC INSPECTION OF INSPAR UPPER SKIN AT REAR SPAR, WBL 157

(SHEET 1 OF 2)

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The step numbers shown below agree with the numbers shown in the circle symbols in the figure.

Step Task Name Identification Qty More Data

Do an HFEC inspection in accordance

with 737 NDT Manual Part 6, 51-00-00

Procedure 4 or Procedure 23 around

the fasteners indicated.

1 Inspect Inspar Upper Skin - -

FIGURE 1: HFEC INSPECTION OF INSPAR UPPER SKIN AT REAR SPAR, WBL 157

(SHEET 2 OF 2)

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This Figure applies only to: Group 1, Configuration 3, 6.

FIGURE 2: HFEC INSPECTION OF INSPAR UPPER SKIN AND REPAIR DOUBLER AT REAR SPAR, WBL

157

(SHEET 1 OF 2)

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Step Task Name Identification Qty More Data

Do an HFEC inspection in accordance

with 737 NDT Manual Part 6, 51-00-00

Procedure 4 or Procedure 23 around

the fasteners indicated. (a)

Inspar Upper Skin and - -

Repair Doubler

1 Inspect

Do an HFEC inspection in accordance

with 737 NDT Manual Part 6, 51-00-00

Procedure 4 or Procedure 23 along the

forward edge of the

repair doubler.

2 Inspect Inspar Upper Skin - -

(a) It is a requirement that the repair doubler is the same material, thickness, and profile as repair drawing

65C30105.

FIGURE 2: HFEC INSPECTION OF INSPAR UPPER SKIN AND REPAIR DOUBLER AT REAR SPAR, WBL

157

(SHEET 2 OF 2)

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This Figure applies only to: Group 1, Configuration 4, 7.

FIGURE 3: HFEC AND LFEC INSPECTION OF INSPAR UPPER SKIN, REPAIR DOUBLER, AND REPAIR

TRIPLER AT REAR SPAR, WBL 157

(SHEET 1 OF 2)

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Step Task Name Identification Qty More Data

Do an HFEC inspection in accordance

with 737 NDT Manual Part 6, 51-00-00

Procedure 4 or Procedure 23 around

the fasteners indicated. (a)

1 Inspect Repair Tripler - -

Do a Low Frequency

Eddy Current

(LFEC) inspection in

accordance with 737

NDT Manual Part 6,

51-00-26 around the

fasteners indicated.

(a)

2 Inspect Repair Doubler - -

Do an HFEC inspection in accordance

with 737 NDT Manual Part 6, 51-00-00

Procedure 4 or Procedure 23 along the

aft edge of the repair

doubler.

3 Inspect Inspar Upper Skin - -

(a) It is a requirement that the repair doubler and the repair tripler are the same material, thickness, and

profile as repair drawing 65C30113.

FIGURE 3: HFEC AND LFEC INSPECTION OF INSPAR UPPER SKIN, REPAIR DOUBLER, AND REPAIR

TRIPLER AT REAR SPAR, WBL 157

(SHEET 2 OF 2)

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