# Boeing Alert Service Bulletin 737-53A1301: U.S. DOT/FAA - Boeing Service Bulletin

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- Document: [Boeing Alert Service Bulletin 737-53A1301](https://openairdocs.org/service-documents/boeing/737-53a1301.md)
- Title as filed: U.S. DOT/FAA - Boeing Service Bulletin
- Pages: 24
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## Text

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### Page 1

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
Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15
CFR 730-774). 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 © 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Unpublished Work - All Rights Reserved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
subject matter. Boeing also claims copyright in this document as a compilation and/or collective work.
This document includes proprietary information owned by The Boeing Company and/or one or more third parties.
Treatment of the document and the information it contains is governed by contract with Boeing. For more
information, contact The Boeing Company, P.O. Box 3707, Seattle, Washington 98124.
Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, Dreamliner,
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Table of Contents
Summary ...................................................... 5
1. PLANNING INFORMATION ........................................ 9
A. Effectivity ................................................ 9
1. Airplanes ............................................. 9
2. Spares Affected ........................................ 1 2
B. Concurrent Requirements ...................................... 1 2
C. Reason ................................................ 1 2
D. Description .............................................. 1 2
E. Compliance .............................................. 1 3
F. Approval ............................................... 1 4
G. Manpower .............................................. 1 4
H. Weight and Balance Changes .................................... 1 5
I. Electrical Load Data ......................................... 1 5
J. References .............................................. 1 5
1. Existing Data .......................................... 1 5
2. Data supplied with this Service Bulletin ............................ 1 5
3. Installation Drawings Used in the Preparation of this Service Bulletin ............ 1 5
K. Publications Affected ........................................ 1 6
L. Interchangeability and Intermixability of Parts ........................... 1 6
2. MATERIAL INFORMATION ........................................ 1 7
A. Material - Price and Availability ................................... 1 7
B. Industry Support Information .................................... 1 7
C. Parts Necessary For Each Airplane ................................. 1 7
1. Kits/Parts ............................................ 1 7
2. Parts and Materials Supplied by the Operator ........................ 1 7
3. Parts Modified and Reidentified ................................ 1 7
4. Parts Removed and Not Replaced .............................. 1 7
D. Parts Necessary to Change Spares ................................. 1 7
E. Special Tooling - Price and Availability ............................... 1 7
F. Special Tooling Necessary to do this Service Bulletin ....................... 1 7
3. ACCOMPLISHMENT INSTRUCTIONS .................................. 1 9
A. GENERAL INFORMATION ..................................... 1 9
B. WORK INSTRUCTIONS ....................................... 1 9
FIGURE 1: FUSELAGE - SKIN AT AREA WITH ELT ANTENNA PROVISION BETWEEN STA 827 AND
STA 847 - NON DESTRUCTIVE INSPECTION [Group 2] .................. 2 1
FIGURE 2: FUSELAGE - SKIN AT AREA WITH ELT ANTENNA PROVISION BETWEEN STA 827 AND
STA 847 - NON DESTRUCTIVE INSPECTION [Group 1] .................. 2 3
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Commercial 
Airplanes
737
Service Bulletin
ALERT
SummaryNumber: 737-53A1301Original 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
Elapsed HoursTotal Task HoursAirplanes
3.004.00Group 1
3.004.00Group 2
MATERIAL INFORMATION
None.
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BOEING SERVICE BULLETIN 737-53A1301
ALERT  ALERT
DO AN MFEC INSPECTION, OR AN MOI
INSPECTION, OR A C-SCAN INSPECTION
FOR CRACKING OF THE FUSELAGE
SKIN ALONG THE CHEM-MILL LINES. IF
ANY CRACK IS FOUND, CONTACT
BOEING FOR REPAIR INSTRUCTIONS
AND INSTALL THE REPAIR.
SKIN AND DOUBLER - EMERGENCY
LOCATOR TRANSMITTER ANTENNA
LOCATION
STA  STA  STA
827  847  867
S-2R -
TYPICAL
CRACK
S-1
S-2L •
DORSAL FIN
DOUBLER  FAIRING
NDI INSPECTION AREA
20 INCH TEAR STRAP DOUBLER SHOWN  1878015
10 INCH TEAR STRAP DOUBLER EQUIVALENT
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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
DESCRIPTIONCONFIGURATIONGROUP
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
GroupVariable Number
2PJ604 - PJ615
2PM543 - PM550
2PP518 - PP520
2PP876 - PP877
2PQ297 - PQ299
2PQ345 - PQ348
2PQ370 - PQ373
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GroupVariable Number
2PQ391 - PQ395
2PQ408 - PQ410
2PQ414 - PQ418
2PQ431 - PQ438
2PQ447 - PQ448
2PQ451
2PQ454
2PQ473 - PQ475
2PQ772
1PQ931 - PQ932
2PQ933 - PQ935
2PQ951
2PQ971 - PQ997
2PR001 - PR017
2PR021 - PR034
2PR041 - PR045
2PR061 - PR072
2PR077 - PR082
2PR091 - PR092
2PR096
2PR101
2PR121 - PR122
2PR131 - PR132
2PR141 - PR143
2PR161 - PR172
2PR181
2PS617 - PS630
2PS704 - PS706
2PS763 - PS799
2PS811
2PS836 - PS837
2PS841 - PS846
2PS851 - PS852
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GroupVariable Number
2PS856
2PS861 - PS863
2PS866 - PS868
2PS871 - PS874
2PS896 - PS897
2PS901 - PS941
2PS956 - PS957
2PS961 - PS963
2PS971 - PS978
2PT012 - PT015
2PT029 - PT031
2PT064
2PT126 - PT138
1PT181 - PT187
2PT188
1PT295
2PT307 - PT309
2PT513 - PT517
2PT585 - PT586
2PT643 - PT644
2PT656
2PT681 - PT685
1PT701 - PT703
2PT716 - PT717
2PT721 - PT725
2PT801 - PT834
2PT851 - PT854
2PT871 - PT886
2PT901 - PT930
2PT971 - PT973
2PT981 - PT985
2PT996
2PU301
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GroupVariable Number
2PU311 - PU313
2PV229
2PV356 - PV357
2PW168 - PW171
2PW263 - PW264
2PW405 - PW408
2PW416 - PW418
2PW421 - PW424
2PW431 - PW435
2PW441 - PW450
2PW853 - PW856
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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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
ZoneModel
108737-300, 737-500
Group 2:
Affected Maintenance Zones
ZoneModel
108737-300, 737-400, 737-500
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)
ActionCondition
500 flight cycles
from the previous
(NDI) inspection.
Within 500 flight
cycles after the
date on this ser-
vice bulletin.
Before 35,000
total flight cy-
cles.
Do an external Non De-
structive Inspection (NDI):
Medium Frequency Eddy
Current (MFEC) or Mag-
neto Optical Imaging
(MOI) or C-Scan, Inspec-
tion for cracking in the
fuselage skin chem-mill
steps at stringers S-1 and
S-2R between STA 827
and STA 847 in accor-
dance with Accomplish-
ment Instructions 3.B.1 or
3.B.2. (a)
All Airplanes
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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)
ActionCondition
-Before further flight.Do not cut out the dam-
age prior to receiving re-
pair 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 instruc-
tions 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:
Elapsed HoursTask HoursNumber of PersonsTask
1.001.001Get Access
1.002.002Figure 2
1.001.001Close Access
3.004.00TOTAL FOR EACH AIRPLANE
Group 2:
Elapsed HoursTask HoursNumber of PersonsTask
1.001.001Get Access
1.002.002Figure 1
1.001.001Close Access
3.004.00TOTAL FOR EACH AIRPLANE
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
TitleDrawing Number
SKIN INSTL - STA 727 TO STA 908, S-10L TO S-10R65C35772
SKIN PANEL INSTL - S-10L TO S-10R STA 727 TO STA 101665-45772
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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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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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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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(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
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### Page 21 (OCR)

BOEING SERVICE BULLETIN 737-53A1301
ALERT  ALERT
This Figure applies only to: Group 2.
00000/
SKIN AND DOUBLER - EMERGENCY
LOCATOR TRANSMITTER ANTENNA
TYPICAL CRACK  LOCATION
STA  STA  STA
827  847  867
S-2R -
S-1
S-2L
DORSAL FIN
FAIRING
DOUBLER
NDI INSPECTION AREA
FIGURE 1: FUSELAGE - SKIN AT AREA WITH ELT ANTENNA PROVISION BETWEEN STA 827 AND STA
847 - NON DESTRUCTIVE INSPECTION
(SHEET 1 OF 2)
Original Issue: September 03, 2009
737-53A1301
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.  21 of 24

### Page 22

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for this figure.
MORE DATAQTYIDENTIFICATIONNAMETASKSTEP
(a)--SkinInspect1
(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
ALERTALERT

### Page 23 (OCR)

BOEING SERVICE BULLETIN 737-53A1301
ALERT  ALERT
This Figure applies only to: Group 1.
00000/
DD
SKIN AND DOUBLER - EMERGENCY
LOCATOR TRANSMITTER ANTENNA
LOCATION
TYPICAL CRACK
STA  STA  STA
827  847  867
S-2R
S-1
S-2L -
DORSAL FIN
DOUBLER  FAIRING
NDI INSPECTION AREA
FIGURE 2: FUSELAGE - SKIN AT AREA WITH ELT ANTENNA PROVISION BETWEEN STA 827 AND STA
847 - NON DESTRUCTIVE INSPECTION
(SHEET 1 OF 2)
Original Issue: September 03, 2009
737-53A1301
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.  23 of 24

### Page 24

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for this figure.
MORE DATAQTYIDENTIFICATIONNAMETASKSTEP
(a)--SkinInspect1
(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
ALERTALERT

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