Commercial 

Airplanes 737

Service Bulletin

ALERT

Number: 737-53A1301

Original Issue: September 03, 2009

ATA System: 5331

SUBJECT: FUSELAGE - Skin - Cracks at Chem-milled Steps in Crown Skins at Specified Locations

- Inspection

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ECCN: 9E991

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Copyright © 2009 The Boeing Company

Unpublished Work - All Rights Reserved

Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable

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This document includes proprietary information owned by The Boeing Company and/or one or more third parties.

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BLANK PAGE
Table of Contents

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

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

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

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

2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

B. Concurrent Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

C. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

E. Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

H. Weight and Balance Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

1. Existing Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

2. Data supplied with this Service Bulletin . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

3. Installation Drawings Used in the Preparation of this Service Bulletin . . . . . . . . . . . . 15

K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

2. MATERIAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

A. Material - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

C. Parts Necessary For Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

1. Kits/Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

2. Parts and Materials Supplied by the Operator . . . . . . . . . . . . . . . . . . . . . . . . 17

3. Parts Modified and Reidentified . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

4. Parts Removed and Not Replaced . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

D. Parts Necessary to Change Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

E. Special Tooling - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

F. Special Tooling Necessary to do this Service Bulletin . . . . . . . . . . . . . . . . . . . . . . . 17

3. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

B. WORK INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

FIGURE 1: FUSELAGE - SKIN AT AREA WITH ELT ANTENNA PROVISION BETWEEN STA 827 AND

STA 847 - NON DESTRUCTIVE INSPECTION [Group 2] . . . . . . . . . . . . . . . . . . 21

FIGURE 2: FUSELAGE - SKIN AT AREA WITH ELT ANTENNA PROVISION BETWEEN STA 827 AND

STA 847 - NON DESTRUCTIVE INSPECTION [Group 1] . . . . . . . . . . . . . . . . . . 23

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BLANK PAGE
Commercial 

Airplanes 737

Service Bulletin

ALERT

Summary Number: 737-53A1301

Original Issue: September 03, 2009

ATA System: 5331

SUBJECT: FUSELAGE - Skin - Cracks at Chem-milled Steps in Crown Skins at Specified Locations

- Inspection

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

Accomplishment of the inspections in this service bulletin will make sure that fuselage skin cracks at stringers

S-1 and S-2R, between Body Stations STA 827 and STA 847 are found and repaired. An Emergency Locator

Transmitter (ELT) Antenna structural full pad up doubler provision is at this location on the affected airplanes.

All airplanes listed in this service bulletin require inspection even if the ELT antenna was not installed or has

been removed. This action is necessary to find and repair fatigue cracking of the skin panel at the chem-mill

steps which could result in rapid decompression of the airplane.

Boeing has received one report from an operator of a hole in the fuselage skin common to stringer S-1 and

S-2L, between STA 827 and STA 847. The crack started along the chem-mill edge along stringer S-1. The

airplane skin in the area had 20 inch tear strap bays. The airplane diverted to an alternate airport due to cabin

depressurization and subsequent deployment of the oxygen masks. The airplane had accumulated 42,569 total

flight cycles. Airplanes with 10 inch tear strap bays are also susceptible to cracks at this location. The cause of

cracking is under investigation.

Boeing Service Related Problem (SRP) 737-SRP-53-0346 is related to this service bulletin.

ACTION

Get external access to the area adjacent to the ELT Antenna provision at stringers S-1 and S-2R, between STA

827 and STA 847.

Do one of the external Non Destructive Inspections (NDI) specified in the compliance section of this service

bulletin for cracking in the fuselage skin along the chem-mill step at stringer S-1 and S-2R, between STA 827

and STA 847. The NDIs that can be used are Medium Frequency Eddy Current (MFEC), Magneto Optical

Imaging (MOI) or C-Scan. If any crack is found, contact Boeing for repair instructions and do the repair. If no

cracking is found, do the repeat inspection in accordance with this service bulletin.

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EFFECTIVITY

737-300/ -400/ -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.

MANPOWER

Airplanes Total Task Hours Elapsed Hours

Group 1 4.00 3.00

Group 2 4.00 3.00

MATERIAL INFORMATION

None.

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BLANK PAGE
Commercial 

Airplanes 737

Service Bulletin

ALERT

Number: 737-53A1301

Original Issue: September 03, 2009

ATA System: 5331

SUBJECT: FUSELAGE - Skin - Cracks at Chem-milled Steps in Crown Skins at Specified Locations

- Inspection

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

GROUP CONFIGURATION DESCRIPTION

737-300/-500 Airplanes with ELT Antenna provisions and 10 inch

tear strap bays

1 -

737-300/-400/-500 Airplanes with ELT Antenna provisions and 20

inch tear strap bays

2 -

Airplane Models:

737-300, 737-400, 737-500

Variable Number Group

PJ604 - PJ615 2

PM543 - PM550 2

PP518 - PP520 2

PP876 - PP877 2

PQ297 - PQ299 2

PQ345 - PQ348 2

PQ370 - PQ373 2

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Variable Number Group

PQ391 - PQ395 2

PQ408 - PQ410 2

PQ414 - PQ418 2

PQ431 - PQ438 2

PQ447 - PQ448 2

PQ451 2

PQ454 2

PQ473 - PQ475 2

PQ772 2

PQ931 - PQ932 1

PQ933 - PQ935 2

PQ951 2

PQ971 - PQ997 2

PR001 - PR017 2

PR021 - PR034 2

PR041 - PR045 2

PR061 - PR072 2

PR077 - PR082 2

PR091 - PR092 2

PR096 2

PR101 2

PR121 - PR122 2

PR131 - PR132 2

PR141 - PR143 2

PR161 - PR172 2

PR181 2

PS617 - PS630 2

PS704 - PS706 2

PS763 - PS799 2

PS811 2

PS836 - PS837 2

PS841 - PS846 2

PS851 - PS852 2

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Variable Number Group

PS856 2

PS861 - PS863 2

PS866 - PS868 2

PS871 - PS874 2

PS896 - PS897 2

PS901 - PS941 2

PS956 - PS957 2

PS961 - PS963 2

PS971 - PS978 2

PT012 - PT015 2

PT029 - PT031 2

PT064 2

PT126 - PT138 2

PT181 - PT187 1

PT188 2

PT295 1

PT307 - PT309 2

PT513 - PT517 2

PT585 - PT586 2

PT643 - PT644 2

PT656 2

PT681 - PT685 2

PT701 - PT703 1

PT716 - PT717 2

PT721 - PT725 2

PT801 - PT834 2

PT851 - PT854 2

PT871 - PT886 2

PT901 - PT930 2

PT971 - PT973 2

PT981 - PT985 2

PT996 2

PU301 2

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BOEING SERVICE BULLETIN 737-53A1301

ALERT ALERT
Variable Number Group

PU311 - PU313 2

PV229 2

PV356 - PV357 2

PW168 - PW171 2

PW263 - PW264 2

PW405 - PW408 2

PW416 - PW418 2

PW421 - PW424 2

PW431 - PW435 2

PW441 - PW450 2

PW853 - PW856 2

2. Spares Affected

None.

B. Concurrent Requirements

None.

C. Reason

Accomplishment of the inspections in this service bulletin will make sure that fuselage skin cracks at

stringers S-1 and S-2R, between Body Stations STA 827 and STA 847 are found and repaired. An

Emergency Locator Transmitter (ELT) Antenna structural full pad up doubler provision is at this location

on the affected airplanes. All airplanes listed in this service bulletin require inspection even if the ELT

antenna was not installed or has been removed. This action is necessary to find and repair fatigue

cracking of the skin panel at the chem-mill steps which could result in rapid decompression of the

airplane.

Boeing has received one report from an operator of a hole in the fuselage skin common to stringer S-1

and S-2L, between STA 827 and STA 847. The crack started along the chem-mill edge along stringer

S-1. The airplane skin in the area had 20 inch tear strap bays. The airplane diverted to an alternate

airport due to cabin depressurization and subsequent deployment of the oxygen masks. The airplane

had accumulated 42,569 total flight cycles. Airplanes with 10 inch tear strap bays are also susceptible

to cracks at this location. The cause of cracking is under investigation.

Boeing Service Related Problem (SRP) 737-SRP-53-0346 is related to this service bulletin.

D. Description

Get external access to the area adjacent to the ELT Antenna provision at stringers S-1 and S-2R,

between STA 827 and STA 847.

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BOEING SERVICE BULLETIN 737-53A1301

ALERT ALERT
Do one of the external Non Destructive Inspections (NDI) specified in the compliance section of this

service bulletin for cracking in the fuselage skin along the chem-mill step at stringer S-1 and S-2R,

between STA 827 and STA 847. The NDIs that can be used are Medium Frequency Eddy Current

(MFEC), Magneto Optical Imaging (MOI) or C-Scan. If any crack is found, contact Boeing for repair

instructions and do the repair. If no cracking is found, do the repeat inspection in accordance with this

service bulletin.

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

Group 1:

Affected Maintenance Zones

Model Zone

737-300, 737-500 108

Group 2:

Affected Maintenance Zones

Model Zone

737-300, 737-400, 737-500 108

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.

Table 1: Fuselage Skin Inspections at Stringers S-1 and S-2R, STA 827 - STA 847

Repeat Interval

(Not to Exceed)

Compliance Time (Whichever

Occurs Later)

Condition Action

500 flight cycles

from the previous

(NDI) inspection.

Within 500 flight

cycles after the

date on this service bulletin.

Before 35,000

total flight cycles.

Do an external Non Destructive Inspection (NDI):

Medium Frequency Eddy

Current (MFEC) or Magneto Optical Imaging

(MOI) or C-Scan, Inspection for cracking in the

fuselage skin chem-mill

steps at stringers S-1 and

S-2R between STA 827

and STA 847 in accordance with Accomplishment Instructions 3.B.1 or

3.B.2. (a)

All Airplanes

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BOEING SERVICE BULLETIN 737-53A1301

ALERT ALERT
Table 1: Fuselage Skin Inspections at Stringers S-1 and S-2R, STA 827 - STA 847

Repeat Interval

(Not to Exceed)

Compliance Time (Whichever

Occurs Later)

Condition Action

Do not cut out the dam- Before further flight. -

age prior to receiving repair instructions from

Boeing. It is likely that the

cutout will be requested

for further metallurgical

analysis so the cutout will

likely be larger than a

typical repair. Contact

Boeing for repair instructions and do the repair.

Any crack found in the

fuselage skin

(a) It is not necessary to inspect the chem-mill steps under an existing external repair doubler provided all of

the following apply:

1. The repair was installed after the release date of this service bulletin.

2. The repair was approved by the FAA or by a Boeing company authorized representative who was

authorized by the FAA to make such findings, and

3. The repair extends a minimum of three rows of fasteners on each side of the chem-mill line in the

circumferential direction.

F. Approval

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

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

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

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

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

changes.

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

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

before incorporating this service bulletin.

G. Manpower

The table below shows an estimate of the task hours necessary to do this inspection 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

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• Time to cure the materials

• Time to make the parts

• Time to find the tools.

Group 1:

Task Number of Persons Task Hours Elapsed Hours

Get Access 1 1.00 1.00

Figure 2 2 2.00 1.00

Close Access 1 1.00 1.00

TOTAL FOR EACH AIRPLANE 4.00 3.00

Group 2:

Task Number of Persons Task Hours Elapsed Hours

Get Access 1 1.00 1.00

Figure 1 2 2.00 1.00

Close Access 1 1.00 1.00

TOTAL FOR EACH AIRPLANE 4.00 3.00

H. Weight and Balance Changes

None.

I. Electrical Load Data

Not changed.

J. References

1. Existing Data

a. Service Related Problem (SRP) 737-53-0346

b. 737 Nondestructive Test (NDT) Manual, Part 6, Subject Eddy Current

2. Data supplied with this Service Bulletin

None.

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

Drawing Number Title

65C35772 SKIN INSTL - STA 727 TO STA 908, S-10L TO S-10R

65-45772 SKIN PANEL INSTL - S-10L TO S-10R STA 727 TO STA 1016

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BOEING SERVICE BULLETIN 737-53A1301

ALERT ALERT
These drawings were used to prepare this service bulletin. These drawings are not necessary to

make the specified changes, and are not supplied with this service bulletin. These drawings may

not be applicable to all airplane configurations or operators.

K. Publications Affected

1. Publications:

None.

2. Damage Tolerance Based Structural Inspections:

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

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

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

L. Interchangeability and Intermixability of Parts

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

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ALERT ALERT
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

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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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. The instructions identified in Paragraph 3.B., Work Instructions, and the Figure(s)

give the recommended sequence of steps. The sequence of steps to do this service

bulletin can be changed.

2. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for

definition of the acronyms.

3. Obey all of the warnings and cautions given in the specified manual sections.

4. A Special Detailed Inspection is defined as: An intensive examination of a specific

item, installation, or assembly to detect damage, failure, or irregularity. The

examination is likely to make extensive use of specialized Inspection Techniques

and/or equipment. Intricate cleaning and substantial access or disassembly procedure

may be required.

5. 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.

B. WORK INSTRUCTIONS

1. Group 1:

a. Initial Inspection

(1) Get external access to the area around the ELT antenna provision at stringer S-1 and

S-2R between STA 827 and STA 847.

(2) Do an NDI Inspection using one of the following methods - Medium Frequency Eddy

Current (MFEC), Magneto Optical Imaging (MOI) or C-Scan, for cracking in the fuselage

skin along the chem-mill step at stringer S-1 and S-2R between STA 827 and STA 847

in accordance with FIGURE 2.

(3) If any crack is found, contact Boeing for repair instructions and do the repair.

(4) If no crack is found do the repeat inspection in accordance with Paragraph 1.E.,

Compliance.

b. Repeat Inspections

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BOEING SERVICE BULLETIN 737-53A1301

ALERT ALERT
(1) Get external access to the area around the ELT antenna provision at stringer S-1 and

S-2R between STA 827 and STA 847.

(2) Do an NDI Inspection using one of the following methods - Medium Frequency Eddy

Current (MFEC), Magneto Optical Imaging (MOI) or C-Scan, for cracking in the fuselage

skin along the chem-mill step at stringer S-1 and S-2R between STA 827 and STA 847

in accordance with FIGURE 2.

(3) If any crack is found, contact Boeing for repair instructions and do the repair.

(4) If no crack is found do the repeat inspection in accordance with Paragraph 1.E.,

Compliance.

2. Group 2:

a. Initial Inspection

(1) Get external access to the area around the ELT antenna provision at stringer S-1 and

S-2R between STA 827 and STA 847.

(2) Do an NDI Inspection using one of the following methods - Medium Frequency Eddy

Current (MFEC), Magneto Optical Imaging (MOI) or C-Scan, for cracking in the fuselage

skin along the chem-mill step at stringer S-1 and S-2R between STA 827 and STA 847

in accordance with FIGURE 1

(3) If any crack is found, contact Boeing for repair instructions and do the repair.

(4) If no crack is found do the repeat inspection in accordance with Paragraph 1.E.,

Compliance.

b. Repeat Inspections

(1) Get external access to the area around the ELT antenna provision at stringer S-1 and

S-2R between STA 827 and STA 847.

(2) Do an NDI Inspection using one of the following methods - Medium Frequency Eddy

Current (MFEC), Magneto Optical Imaging (MOI) or C-Scan, for cracking in the fuselage

skin along the chem-mill step at stringer S-1 and S-2R between STA 827 and STA 847

in accordance with FIGURE 1.

(3) If any crack is found, contact Boeing for repair instructions and do the repair.

(4) If no crack is found do the repeat inspection in accordance with Paragraph 1.E.,

Compliance.

3. Put the airplane back to a serviceable condition.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: September 03, 2009

737-53A1301

20 of 24

BOEING SERVICE BULLETIN 737-53A1301

ALERT ALERT
This Figure applies only to: Group 2.

FIGURE 1: FUSELAGE - SKIN AT AREA WITH ELT ANTENNA PROVISION BETWEEN STA 827 AND STA

847 - NON DESTRUCTIVE INSPECTION

(SHEET 1 OF 2)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: September 03, 2009

737-53A1301

21 of 24

BOEING SERVICE BULLETIN 737-53A1301

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

numbers shown below are the number of parts necessary for this figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Inspect Skin - - (a)

(a) Do an external eddy current inspection for chem-mill cracks as given in 737 NDT [Part 6, 53-30-09] or

737 NDT [Part 6, 53-30-18] or 737 NDT [Part 6, 53-30-19] or 737 NDT [Part 6, 53-30-25].

FIGURE 1: FUSELAGE - SKIN AT AREA WITH ELT ANTENNA PROVISION BETWEEN STA 827 AND STA

847 - NON DESTRUCTIVE INSPECTION

(SHEET 2 OF 2)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: September 03, 2009

737-53A1301

22 of 24

BOEING SERVICE BULLETIN 737-53A1301

ALERT ALERT
This Figure applies only to: Group 1.

FIGURE 2: FUSELAGE - SKIN AT AREA WITH ELT ANTENNA PROVISION BETWEEN STA 827 AND STA

847 - NON DESTRUCTIVE INSPECTION

(SHEET 1 OF 2)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: September 03, 2009

737-53A1301

23 of 24

BOEING SERVICE BULLETIN 737-53A1301

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

numbers shown below are the number of parts necessary for this figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Inspect Skin - - (a)

(a) Do an external eddy current inspection for chem-mill cracks as given in 737 NDT [Part 6, 53-30-09] or

737 NDT [Part 6, 53-30-18] or 737 NDT [Part 6, 53-30-19] or 737 NDT [Part 6, 53-30-25].

FIGURE 2: FUSELAGE - SKIN AT AREA WITH ELT ANTENNA PROVISION BETWEEN STA 827 AND STA

847 - NON DESTRUCTIVE INSPECTION

(SHEET 2 OF 2)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: September 03, 2009

737-53A1301

24 of 24

BOEING SERVICE BULLETIN 737-53A1301

ALERT ALERT