Commercial 

Airplanes 737

Service Bulletin

ALERT

Number: 737-53A1163

Original Issue: December 21, 1993

Revision 1: January 08, 2014

ATA System: 5331

SUBJECT: FUSELAGE - Skin - Forward Entry Doorway Skin Cutout - Upper Forward and Upper

Aft Corners - Inspection, Modification, and Repair

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 © 1993 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Unpublished Work.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.

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BOEING SERVICE BULLETIN 737-53A1163

ALERT ALERT

BLANK PAGE
Table of Contents

Revision Transmittal Sheet ............................................ 5

Summary ...................................................... 9

1. PLANNING INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

A. Effectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

1. Airplanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

B. Concurrent Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

C. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

E. Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

H. Weight and Balance Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

1. Existing Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

2. Data Supplied with this Service Bulletin: . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

3. Installation Drawings Used in the Preparation of this Service Bulletin: . . . . . . . . . . . 34

K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

M. Software Accomplishment Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

2. MATERIAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

A. Material - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

C. Parts Necessary for Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

1. Kits/Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

2. Parts and Materials Supplied by the Operator . . . . . . . . . . . . . . . . . . . . . . . . 42

3. Parts Modified and Reidentified . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

4. Parts Removed and Not Replaced . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

D. Parts Necessary to Change Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

E. Special Tooling - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

F. Special Tooling Necessary to do this Service Bulletin . . . . . . . . . . . . . . . . . . . . . . . 43

3. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

B. WORK INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

FIGURE 1: THIS FIGURE WAS DELETED AT REVISION 1 . . . . . . . . . . . . . . . . . . . . . . . 51

FIGURE 2: FORWARD ENTRY DOORWAY - BEARSTRAP AND SKIN ASSEMBLY - INSPECTION [Group

1, Configuration 2; Group 3] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

FIGURE 3: FORWARD ENTRY DOORWAY - BEARSTRAP AND SKIN ASSEMBLY - INSPECTION [Group

2, Configuration 2] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

FIGURE 4: FORWARD ENTRY DOORWAY - BEARSTRAP AND SKIN ASSEMBLY - CRACK REMOVAL

[Group 1, Configuration 2] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

FIGURE 5: FORWARD ENTRY DOORWAY - BEARSTRAP AND SKIN ASSEMBLY - CRACK REMOVAL

[Group 2, Configuration 2] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

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ALERT ALERT

BLANK PAGE
Commercial 

Airplanes 737

Service Bulletin

ALERT

Revision Transmittal Sheet Number: 737-53A1163

Original Issue: December 21, 1993

Revision 1: January 08, 2014

ATA System: 5331

SUBJECT: FUSELAGE - Skin - Forward Entry Doorway Skin Cutout - Upper Forward and Upper

Aft Corners - Inspection, Modification, and Repair

This revision includes all pages of the service bulletin.

COMPLIANCE INFORMATION RELATED TO THIS REVISION

More work is necessary on airplanes that have not installed the repair or preventive modification in accordance

with the original issue of this service bulletin. Inspection areas are increased and inspections methods are

changed.

No more work is necessary on the airplanes that have installed the repair or preventive modification in accordance

with the original issue of this service bulletin.

737-300/-400/-500 airplanes line numbers 1923 to 3132 are added to new Group 3 of this service bulletin

effectivity.

Federal Aviation Administration (FAA) Airworthiness Directives AD 98-11-04 R1, AD 2008-08-23 and AD

2008-09-13 are related to this service bulletin.

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.

REASON FOR REVISION

This revision is sent to add new airplanes to the service bulletin effectivity. This revision is also sent to increase

the inspection area, to remove internal inspection and to change external inspection methods for group 1 and

2 airplanes.

Airplane line numbers 1 through 291 are moved from Group 1 and 2 to new Group 4. 737-300/-400/-500 airplanes

line numbers 1923 to 3132 are added to new Group 3 of this service bulletin effectivity.

Terminology has been changed in the Work Instructions to agree with the terminology defined in Paragraph

3.A., General Information - Notes.

These sections were changed:

1. Title changed to add primary section affected by this service bulletin.

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2. Summary Section: Updated Background and added new service history, summary planning table, fleet

team digest reference and service related problem reference.

3. Summary Section - Updated Action with increased inspection areas, changed inspection methods and

instructions for new airplanes.

4. Summary Section - Updated Effectivity, Industry Support Information, Manpower and Material Information

sections.

5. Summary Section - Compliance: Added related FAA Airworthiness Directives.

6. Paragraph 1.C., Reason - added new service history, fleet team digest reference, service related

problem reference, reason for revision and Notice of Status Change 1 reference.

7. Paragraph 1.D., Description - Added increased inspection areas, changed inspection methods and

instructions for new airplanes. Added maintenance zone tables.

8. Paragraph 1.E., Compliance - Added related FAA Airworthiness Directives. Added new compliance

tables 1, 2 and 3.

9. Paragraph 1.F., Approval - Added new approval paragraph and alternative methods of compliance for

related FAA Airworthiness Directives.

10. Paragraph 1.G., Manpower - Updated manpower tables for Group 1 and 2.

11. Paragraph 1.J., References - Existing Data list is updated and new drawing is added to Data Supplied

with this Service Bulletin.

12. Paragraph 1.K.2., Damage Tolerance Based Structural Inspections - Added new section.

13. Paragraph 1.L., Interchangeability and Intermixability of Parts - Added new section.

14. Paragraph 1.M., Software Accomplishment Summary - Added new section.

15. Paragraph 2.A., Material - Price and Availability - Updated prices for all kits.

16. Paragraph 2.B., Industry Support Information - Updated warranty information.

17. Paragraph 2.C., Parts Necessary for Each Airplane - Added kit tables.

18. Paragraph 3.A., General Information - Added new notes.

19. Paragraph 3.B., Work Instructions - Updated instructions for Group 1 and 2. Added new instructions

for Group 3.

20. Figure 1 has been deleted.

21. Figures 2 and 3 have been added to show increased inspection areas and changed inspection methods.

22. Figures 4 and 5 have been added to show crack removal.

The data given in Notice of Status Change 737-53-1163 NSC 1 related to inspections is not included in revision

1 of this service bulletin as the inspections have been replaced.

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BOEING SERVICE BULLETIN 737-53A1163

ALERT ALERT
The data given in Notice of Status Change 737-53-1163 NSC 1 related to kit prices is included in revision 1 of

this service bulletin.

Vertical lines are put on the left edge of each page, except in Paragraph 1.A., Effectivity, to show the location

of important changes.

Pages with no vertical lines have no important changes.

REVISION HISTORY

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BOEING SERVICE BULLETIN 737-53A1163

ALERT ALERT

BLANK PAGE
Commercial 

Airplanes 737

Service Bulletin

ALERT

Summary Number: 737-53A1163

Original Issue: December 21, 1993

Revision 1: January 08, 2014

ATA System: 5331

SUBJECT: FUSELAGE - Skin - Forward Entry Doorway Skin Cutout - Upper Forward and Upper

Aft Corners - Inspection, Modification, and Repair

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

Seventeen operators have found cracks in the upper corners of the forward entry door skin cutout. The airplanes

had collected from 33,150 to 76,242 flight cycles. The cause of the cracks is fatigue from cabin pressure.

Continued operation with cracks in the doorway upper corners can result in cabin depressurization and

unscheduled downtime for repairs.

Installation of doublers as given in this service bulletin can prevent cracks at the doorway upper corners.

Since the release of the original issue of this service bulletin there have been 3 reports of cracking at the forward

entry doorway upper corners on airplanes that were outside the effectivity of the original issue of this service

bulletin. The reports are listed below.

Service History

Cycles/Hours Report

59804 / 69512 1 inch crack common to the bearstrap only found at the upper forward corner.

31238 / 37443 Crack in the skin only at the upper aft corner.

38126 / 46173 Crack in skin only at the upper forward corner.

Boeing Fleet Team Digest (FTD) 737 FTD 53-11003 is related to this service bulletin.

Boeing Service Related Problem (SRP) 737-SRP-53-0381 is related to this service bulletin.

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

information.

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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 Yes 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 Yes Paragraph 2.C.1., Kits/Parts

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

by the Operator

Operator Supplied Material Yes

Paragraph 2.F., Special Tooling Necessary to

do this Service Bulletin

Special Tooling Required No

ACTION

Group 1-2, Configuration 1:

Airplanes with the repair/preventive modification installed in accordance with the original issue of this SB are

not required to be inspected in accordance with the SB. Post repair/preventive modification inspections are

provided in the D6-38669 Repair Assessment Guidelines document.

Group 1-2, Configuration 2; Group 3:

Get access to the upper corners of the forward entry doorway. Do an external detailed inspection and a Low

Frequency Eddy Current (LFEC) inspection of the skin assembly and bearstrap for any crack at the upper corners

of the forward entry doorway.

Group 1-2, Configuration 2:

If any crack is found in the skin assembly and/or bearstrap, install a repair in accordance with this service bulletin.

If no cracks are found, install the preventive modification or do repeat inspections at the times given in Paragraph

1.E., Compliance.

Group 3:

If any crack is found in the skin assembly and/or bearstrap, install a repair in accordance with this service bulletin

and do repeat inspections of the area not covered by the repair at the times given in Paragraph 1.E., Compliance.

If no cracks are found, install the preventive modification or do repeat inspections of the entire inspection area

at the times given in Paragraph 1.E., Compliance.

Group 4:

On Group 4 airplanes, contact Boeing to get instructions for the inspection and/or repair for this service bulletin,

737-53A1163 Revision 1, and do the work instructed by Boeing.

EFFECTIVITY

All 737-100/-200/-200C/-300/-400/-500 Airplane(s). Refer to Paragraph 1.A.1., Airplanes, for the list of affected

airplane(s).

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ALERT ALERT
COMPLIANCE

Federal Aviation Administration (FAA) Airworthiness Directives AD 98-11-04 R1, AD 2008-08-23 and AD

2008-09-13 are related to this service bulletin.

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

Boeing warranty remedies are not available for the inspection, and/or repair/preventive modification procedures

given in this service bulletin.

MANPOWER

Refer to Paragraph 1.G., Manpower.

MATERIAL INFORMATION

Group 1-2, Configuration 1; Group 3-4:

None.

Group 1-2, Configuration 2:

Boeing Supplied Kits/Parts.

Group 1-2, Configuration 2:

Refer to Paragraph 2.A., Material - Price and Availability.

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BOEING SERVICE BULLETIN 737-53A1163

ALERT ALERT
Commercial 

Airplanes 737

Service Bulletin

ALERT

Number: 737-53A1163

Original Issue: December 21, 1993

Revision 1: January 08, 2014

ATA System: 5331

SUBJECT: FUSELAGE - Skin - Forward Entry Doorway Skin Cutout - Upper Forward and Upper

Aft Corners - Inspection, Modification, and Repair

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.

GROUP CONFIGURATION DESCRIPTION

1 - 737-200/-300/-400/-500 series airplanes, line numbers 292-1922.

Airplanes that have accomplished the repair or preventive modification

in accordance with the original issue of this service bulletin.

1

Airplanes that have not accomplished the repair or preventive

modification in accordance with the original issue of this service

bulletin.

2

2 - 737-200C series airplanes, line numbers 292-1113.

Airplanes that have accomplished the repair or preventive modification

in accordance with the original issue of this service bulletin.

1

Airplanes that have not accomplished the repair or preventive

modification in accordance with the original issue of this service

bulletin.

2

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GROUP CONFIGURATION DESCRIPTION

3 - 737-300/-400/-500 series airplanes, line numbers 1923-3132.

4 - 737-100/-200/-200C series airplanes, line numbers 1-291.

Airplane Models:

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

Variable Number Group

PA001 - PA022 4

PA099 4

PA231 - PA232 4

PC001 - PC005 4

PG001 - PG075 4

PG199 4

PG201 - PG230 4

PG251 - PG255 4

PG271 - PG279 4

PG301 - PG314 4

PG331 - PG332 4

PG351 - PG356 4

PG375 4

PG401 - PG403 4

PG431 - PG442 4

PG471 - PG475 4

PG501 - PG505 4

PG571 - PG583 4

PG584 - PG586 1

PG621 - PG630 4

PG651 - PG652 4

PG701 - PG705 4

PH001 1

PH011 - PH013 1

PH021 - PH024 1

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Variable Number Group

PH701 - PH715 4

PH731 - PH732 4

PH741 - PH742 4

PH743 1

PJ001 - PJ002 4

PJ003 - PJ009 1

PJ031 - PJ032 4

PJ071 - PJ072 4

PJ101 - PJ104 4

PJ105 - PJ119 1

PJ201 - PJ219 1

PJ301 - PJ302 3

PJ551 - PJ561 3

PJ601 - PJ615 3

PJ811 3

PJ816 - PJ817 3

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

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Variable Number Group

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

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

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BOEING SERVICE BULLETIN 737-53A1163

ALERT ALERT
Variable Number Group

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

PL611 1

PL621 - PL626 1

PL631 - PL632 1

PL711 - PL712 4

PL716 4

PL717 - PL747 1

PL756 1

PL758 1

PL761 - PL770 1

PL781 - PL788 1

PL793 1

PL801 - PL803 4

PM001 - PM006 1

PM016 - PM017 1

PM021 - PM023 1

PM051 - PM066 1

PM101 - PM119 1

PM141 - PM142 1

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Variable Number Group

PM171 1

PM181 1

PM251 - PM255 1

PM281 - PM283 1

PM381 - PM392 1

PM393 - PM399 3

PM401 - PM417 3

PM541 - PM564 3

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

PN481 1

PN491 - PN493 1

PN501 - PN502 1

PN511 - PN512 1

PN521 1

PP001 - PP054 1

PP101 - PP148 1

PP149 - PP160 3

PP161 - PP169 1

PP181 - PP199 1

PP201 - PP205 1

PP221 1

PP231 - PP243 1

PP281 - PP286 1

PP301 - PP305 1

PP351 - PP353 1

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Variable Number Group

PP376 - PP384 1

PP391 - PP393 1

PP401 - PP440 1

PP471 - PP475 1

PP501 - PP510 1

PP511 - PP520 3

PP521 - 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 - PP873 1

PP874 - PP877 3

PP891 - PP899 1

PP901 - PP924 1

PP925 - PP930 3

PP931 - PP936 1

PP946 - PP948 1

PP951 - PP952 1

PP961 - PP967 1

PP981 - PP987 1

PP988 - PP990 3

PP991 1

PP993 1

PQ001 - PQ016 1

PQ026 - PQ041 1

PQ051 - PQ073 1

PQ074 - PQ085 3

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Variable Number Group

PQ086 - PQ092 1

PQ101 - PQ198 1

PQ199 3

PQ201 - PQ202 3

PQ221 - PQ229 1

PQ230 3

PQ231 - PQ236 1

PQ237 3

PQ241 - PQ243 1

PQ251 - PQ255 1

PQ256 - PQ267 3

PQ281 - PQ286 1

PQ287 - PQ299 3

PQ301 - PQ305 1

PQ306 - PQ307 3

PQ331 - PQ332 1

PQ341 - PQ348 3

PQ361 - PQ373 3

PQ391 - PQ395 3

PQ401 - PQ418 3

PQ421 3

PQ431 - PQ438 3

PQ447 - PQ448 3

PQ451 3

PQ454 3

PQ471 - PQ475 3

PQ479 - PQ481 3

PQ486 - PQ487 3

PQ491 - PQ493 3

PQ771 - PQ772 3

PQ791 - PQ793 3

PQ801 - PQ805 3

PQ931 - PQ935 3

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Variable Number Group

PQ951 3

PQ971 - PQ997 3

PR001 - PR017 3

PR021 - PR034 3

PR041 - PR045 3

PR061 - PR072 3

PR077 - PR082 3

PR091 - PR092 3

PR096 3

PR101 3

PR121 - PR122 3

PR131 - PR132 3

PR141 - PR143 3

PR161 - PR172 3

PR181 3

PS601 - PS631 3

PS636 - PS638 3

PS641 - PS642 1

PS643 - PS644 3

PS651 - PS657 3

PS666 - PS668 1

PS669 3

PS691 - PS692 3

PS701 - PS706 3

PS751 - PS799 3

PS811 3

PS836 - PS837 3

PS841 - PS846 3

PS851 - PS852 3

PS856 3

PS861 - PS863 3

PS866 - PS868 3

PS871 - PS874 3

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Variable Number Group

PS896 - PS897 3

PS901 - PS941 3

PS956 - PS957 3

PS961 - PS963 3

PS971 - PS978 3

PT001 - PT015 3

PT021 - PT023 1

PT024 - PT031 3

PT041 - PT064 3

PT101 1

PT102 - PT105 3

PT121 - PT123 1

PT124 - PT138 3

PT146 1

PT147 - PT148 3

PT161 - PT170 3

PT181 - PT182 1

PT183 - PT188 3

PT211 - PT214 1

PT215 - PT220 3

PT295 1

PT301 - PT309 3

PT331 - PT360 3

PT381 - PT399 3

PT401 - PT438 3

PT501 - PT517 3

PT561 - PT565 3

PT581 - PT586 3

PT611 - PT621 3

PT641 - PT644 3

PT651 - PT656 3

PT671 - PT672 3

PT681 - PT685 3

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Variable Number Group

PT701 - PT703 3

PT716 - PT717 3

PT721 - PT725 3

PT801 - PT834 3

PT851 - PT854 3

PT871 - PT886 3

PT901 - PT930 3

PT971 - PT973 3

PT981 - PT985 3

PT996 3

PU001 - PU007 1

PU008 - PU025 3

PU301 3

PU311 - PU313 3

PV001 - PV040 1

PV041 - PV055 3

PV201 - PV209 3

PV226 - PV229 3

PV231 - PV237 3

PV271 - PV272 3

PV281 - PV287 3

PV296 3

PV301 - PV302 3

PV351 3

PV356 - PV357 3

PW001 - PW036 1

PW037 - PW050 3

PW051 1

PW052 - PW054 3

PW061 - PW063 1

PW064 - PW068 3

PW072 3

PW086 - PW088 3

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Variable Number Group

PW091 - PW093 1

PW094 3

PW101 - PW102 3

PW106 3

PW111 - PW117 1

PW118 - PW120 3

PW156 - PW157 3

PW161 - PW162 1

PW163 - PW171 3

PW201 - PW252 3

PW261 - PW268 3

PW271 - PW276 3

PW278 3

PW281 - PW293 3

PW296 3

PW301 - PW327 3

PW401 - PW408 3

PW411 - PW418 3

PW421 - PW424 3

PW431 - PW435 3

PW441 - PW450 3

PW461 - PW467 3

PW501 - PW503 1

PW504 3

PW511 - PW518 1

PW519 - PW522 3

PW524 - PW530 3

PW531 - PW535 1

PW536 - PW550 3

PW556 - PW557 3

PW561 - PW563 1

PW564 3

PW571 - PW573 1

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Variable Number Group

PW574 - PW576 3

PW591 - PW594 1

PW595 - PW596 3

PW611 - PW615 1

PW616 - PW622 3

PW631 - PW632 1

PW633 - PW637 3

PW661 1

PW662 3

PW681 - PW683 3

PW701 - PW702 3

PW711 - PW717 3

PW741 - PW742 3

PW761 3

PW771 3

PW831 3

PW851 - PW856 3

PX071 4

PX701 4

PY001 - PY008 4

PY021 4

PY022 2

PY031 4

PY036 - PY037 2

PY046 - PY048 2

PY051 - PY053 2

PY056 - PY057 2

PY101 - PY103 2

PY111 - PY113 2

PY131 - PY135 2

PY141 - PY143 2

PY151 - PY154 2

PY156 - PY157 2

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Variable Number Group

PY161 - PY162 2

PY166 2

PY191 2

PY201 2

PY221 - PY222 2

PY231 2

PY241 - PY244 2

PY270 - PY275 2

PY281 2

PY286 2

PY301 - PY304 4

PY321 - PY323 4

PY341 - PY346 4

PY361 - PY362 4

PY381 4

PY401 2

PY409 - PY411 2

PY421 - PY422 2

PY441 2

PY451 2

PY461 - PY463 2

PY591 - PY595 2

PY611 - PY612 2

PY621 2

PY631 2

PY651 2

PY671 - PY672 2

PY721 2

PY741 2

2. Spares Affected

None.

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B. Concurrent Requirements

None.

C. Reason

Seventeen operators have found cracks in the upper corners of the skin at the forward entry doorway.

The airplanes had collected from 33,150 to 76,242 flight cycles. The cause of the cracks is fatigue from

cabin pressure loads. Continued operation with cracks in the doorway upper corners can result in cabin

depressurization and unscheduled downtime for repairs.

Installation of doublers as given in this service bulletin can prevent cracks at the doorway corners.

Since the release of the original issue of this service bulletin there have been 3 reports of cracking at

the forward entry doorway upper corners on airplanes that were outside the effectivity of the original

issue of this service bulletin. The reports are listed below.

Service History

Cycles/Hours Report

59804 / 69512 1 inch crack common to the bearstrap only found at the upper forward corner.

31238 / 37443 Crack in the skin only at the upper aft corner.

38126 / 46173 Crack in skin only at the upper forward corner.

Boeing Fleet Team Digest (FTD) 737 FTD 53-11003 is related to this service bulletin.

Boeing Service Related Problem (SRP) 737-SRP-53-0381 is related to this service bulletin.

Terminology has been changed in the Work Instructions to agree with the terminology defined in

Paragraph 3.A., General Information - Notes.

Revision 1 is sent to add new airplanes to the service bulletin effectivity. Revision 1 is also sent to

increase the inspection area, to remove internal inspection and to change external inspection methods

for group 1 and 2.

The data given in Notice of Status Change 737-53-1163 NSC 1 related to inspections is not included

in revision 1 of this service bulletin as the inspections have been replaced.

The data given in Notice of Status Change 737-53-1163 NSC 1 related to kit prices is included in

revision 1 of this service bulletin.

D. Description

Group 1-2, Configuration 1:

Airplanes with the repair/preventive modification installed in accordance with the original issue of this

SB are not required to be inspected in accordance with the SB. Post repair/preventive modification

inspections are provided in the D6-38669 Repair Assessment Guidelines document.

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ALERT ALERT
Group 1-2, Configuration 2; Group 3:

Get access to the upper corners of the forward entry doorway. Do an external detailed inspection and

a Low Frequency Eddy Current (LFEC) inspection of the skin assembly and bearstrap for any crack

at the upper corners of the forward entry doorway.

Group 1-2, Configuration 2:

If any crack is found in the skin assembly and/or bearstrap, install a repair in accordance with this

service bulletin. If no cracks are found, install the preventive modification or do repeat inspections at

the times given in Paragraph 1.E., Compliance.

Group 3:

If any crack is found in the skin assembly and/or bearstrap, install a repair in accordance with this

service bulletin and do repeat inspections of the area not covered by the repair at the times given in

Paragraph 1.E., Compliance. If no cracks are found, install the preventive modification or do repeat

inspections of the entire inspection area at the times given in Paragraph 1.E., Compliance.

Group 4:

On Group 4 airplanes, contact Boeing to get instructions for the inspection and/or repair for this service

bulletin, 737-53A1163 Revision 1, and do the work instructed by Boeing.

Revision 1 - More work is necessary on airplanes that have not installed the repair or preventive

modification in accordance with the original issue of this service bulletin. Inspection areas are increased

and inspections methods are changed. No more work is necessary on the airplanes that have installed

the repair or preventive modification in accordance with the original issue of 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

737-200 1-3, 1-5, 1-7

Group 1, 3:

Affected Maintenance Zones

Model Zone

737-300, 737-400, 737-500 103, 105, 107

Group 2:

Affected Maintenance Zones

Model Zone

737-200C 1-3, 1-5, 1-7

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Group 4:

Affected Maintenance Zones

Model Zone

737-100, 737-200, 737-200C 1-3, 1-5, 1-7

E. Compliance

Federal Aviation Administration (FAA) Airworthiness Directives AD 98-11-04 R1, AD 2008-08-23 and

AD 2008-09-13 are related to this service bulletin.

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 4:

On Group 4 airplanes, contact Boeing to get instructions for the inspection and/or repair for this service

bulletin, 737-53A1163 Revision 1, and do the work instructed by Boeing, within 120 days of the issue

date of Revision 1 to this service bulletin.

Group 1-2, Configuration 1:

Airplanes with the repair/preventive modification installed in accordance with the original issue of this

SB are not required to be inspected in accordance with the SB. Post repair/preventive modification

inspections are provided in Table 3 of Paragraph 1.E., Compliance.

Group 1-2, Configuration 2:

Table 1: Inspection of Fuselage Skin Assembly and Bearstrap at the Forward Entry Doorway Upper

Corners

Repeat Interval

(Not to Exceed)

Compliance Time (Whichever

Occurs Later)

Condition Action

4,500 Flight Cycles

(a) (b)

Within 4,500

Flight Cycles after the Revision

1 date of this

service bulletin

Before 27,000

Total Flight Cycles

Do an external detailed

inspection of the skin assembly and a Low Frequency Eddy Current

(LFEC) inspection of the

skin assembly and

bearstrap for any crack in

accordance with Paragraph 3.B., Work Instructions, PART 1 - Inspection.

All airplanes

Install the repair in accor- Before further flight. -

dance with Paragraph

3.B., Work Instructions,

PART 3 - Repair.

If any crack is found in the

skin assembly or bearstrap.

(b)

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Group 1-2, Configuration 2:

Table 1: Inspection of Fuselage Skin Assembly and Bearstrap at the Forward Entry Doorway Upper

Corners

Repeat Interval

(Not to Exceed)

Compliance Time (Whichever

Occurs Later)

Condition Action

(a) Accomplishment of the preventive modification in accordance with Original issue or Revision 1 of this

service bulletin terminates the inspection of Table 1. Post preventive modification inspection are provided

in Table 3 of Paragraph 1.E., Compliance.

(b) Accomplishment of the repair in accordance with the Original issue or Revision 1 of this service bulletin

terminates the inspection of Table 1. Post repair inspection are provided in Table 3 of Paragraph 1.E.,

Compliance.

Group 3:

Table 2: Inspection of Fuselage Skin Assembly and Bearstrap at the Forward Entry Doorway Upper

Corners

Repeat Interval

(Not to Exceed)

Compliance Time (Whichever

Occurs Later)

Condition Action

4,500 Flight Cycles

(a) (b)

Within 4,500

Flight Cycles after the Revision

1 date of this

service bulletin.

Before 27,000

Total Flight Cycles

Do an external detailed

inspection of the skin assembly and a LFEC inspection of the skin assembly and bearstrap for

any crack in accordance

with Paragraph 3.B.,

Work Instructions, PART

1 - Inspection.

All Airplanes

Install a repair in accor- Before further flight. -

dance with Paragraph

3.B., Work Instructions,

PART 3 - Repair. (b)

If any crack is found in the

skin assembly or bearstrap.

(a) Accomplishment of the preventive modification in accordance with Revision 1 of this Service Bulletin

terminates the inspection of Table 2. Post preventive modification inspections are provided in the applicable SRM.

(b) Accomplishment of the repair in accordance with Revision 1 of this Service Bulletin terminates the inspection of Table 2 in the repaired area. If a repair is only installed on one corner, inspections in the area not

repaired are still required in accordance with Table 2. Post repair inspections are provided in the applicable

SRM.

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ALERT ALERT
Group 1-2:

Table 3: Inspection of Fuselage Skin Assembly and Bearstrap For Airplanes With a Repair or Preventive

Modification Installed

Repeat Interval

(Not to Exceed)

Compliance Time (Whichever

Occurs Later)

Condition Action

Repeat the inspection at interval in

accordance with

RAG.

Within 12,000

flight cycles after repair has

been installed

Before 60,000

total flight cycles

Do the inspection in accordance with D6-38669,

Repair Assessment

Guidelines-Model 737-

100 to -500.

Airplanes that have installed the repair or preventive modification in accordance with the Original Issue or Revision 1 of this

Service Bulletin.

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.

For Boeing 737-200 series airplanes, the Manager of the FAA Seattle Aircraft Certification Office (ACO)

approves the supplemental inspection methods, thresholds and repeat intervals as given in Table 3 of

Paragraph 1.E., Compliance for the repair or preventive modification defined in Table 1 of Paragraph

1.E., Compliance, of Revision 1 of this service bulletin as a method of compliance (MOC) to paragraph

(g) of AD 98-11-04 R1 for the inspections of Structurally Significant Items (SSI) F-13A and F-14A. This

approval applies to these SSIs and only for the portions of the skin and bear strap that have been

repaired in accordance with this SB. If operators choose this MOC, then they must revise their

FAA-approved maintenance or inspection program to incorporate these alternative inspections. All

provisions of AD 98-11-04 R1 that are not specifically referenced above remain fully applicable and

must be complied with accordingly.

For Boeing 737-200C series airplanes, the Manager of the FAA Seattle ACO approves the inspection

methods, thresholds and repeat intervals as given in Table 3 of Paragraph 1.E., Compliance for the

repair or preventive modification defined in Table 1 of Paragraph 1.E., Compliance, of Revision 1 of

this service bulletin as an alternative method of compliance (AMOC) to the inspections of SSIs F-13A

and F-14A, required by paragraphs (g) and (h) of AD 2008-08-23. This approval applies to these SSIs

and only for the portions of the skin and bear strap that have been repaired in accordance with this

SB. If operators choose this AMOC, then they must revise their FAA-approved maintenance or inspection

program to incorporate these alternative inspections. All provisions of AD 2008-08-23 that are not

specifically referenced above remain fully applicable and must be complied with accordingly.

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ALERT ALERT
For Boeing 737-300/-400/-500 series airplanes identified as Group 1 airplanes, the Manager of the

FAA Seattle ACO approves the inspection methods, thresholds and repeat intervals as given in Table

3 of Paragraph 1.E., Compliance for the repair or preventive modification defined in Table 1 of Paragraph

1.E., Compliance, of Revision 1 of this service bulletin as an AMOC to the inspections of SSIs F-13A

and F-14A, required by paragraphs (g) and (h) of AD 2008-09-13. This approval applies to these SSIs

and only for the portions of the skin and bear strap that have been repaired or modified in accordance

with this SB. If operators choose this AMOC, then they must revise their FAA-approved maintenance

or inspection program to incorporate these alternative inspections. All provisions of AD 2008-09-13

that are not specifically referenced above 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 change 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:

Task Number of Persons Task Hours Elapsed Hours

FIGURE 2 1 3.00 3.00

FIGURE 4 2 5.50 2.75

Open Access 1 1.00 (a) 1.00

Repair (a) 2 60.00 (a) 30.00 (a)

Preventive Modification (a) 2 44.00 (a) 22.00 (a)

Close Access 1 1.00 (a) 1.00

TOTAL FOR EACH AIRPLANE 8.50 5.75

(a) The Repair and Preventive Modification estimates are not included in the total estimates.

Group 2, Configuration 2:

Task Number of Persons Task Hours Elapsed Hours

FIGURE 3 1 3.00 3.00

FIGURE 5 2 5.50 2.75

Open Access 1 1.00 (a) 1.00

Repair (a) 2 60.00 (a) 30.00 (a)

Preventive Modification (a) 2 44.00 (a) 22.00 (a)

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Group 2, Configuration 2:

Task Number of Persons Task Hours Elapsed Hours

Close Access 1 1.00 (a) 1.00 (a)

TOTAL FOR EACH AIRPLANE 8.50 5.75

(a) The Repair and Preventive Modification estimates are not included in the total estimates.

Group 3:

Task Number of Persons Task Hours Elapsed Hours

FIGURE 2 1 3.00 3.00

H. Weight and Balance Changes

Group 1, Configuration 2:

Change in Change in Moment (Pound-Inches)

Weight

(Pounds)

Kit

737-100 737-200 737-300 737-400 737-500

65C36941-1 + 3.9 + 1279.2 + 1138.8 + 967.2 + 686.4 + 1177.8

65C36941-5 + 5.8 + 1902.4 + 1693.6 + 1438.4 + 1020.8 + 1751.6

65C36941-7 + 10.1 + 3312.8 + 2949.2 + 2504.8 + 1777.6 + 3050.2

Group 2, Configuration 2:

737-200C Model Series Airplanes

Change in Moment

(Pound-Inches)

Change in Weight

Kit (Pounds)

65C36941-13 + 5.6 + 1635.2

65C36941-15 + 7.6 + 2219.2

65C36941-17 + 10.6 + 3095.2

Group 1-2, Configuration 1; Group 3-4:

None.

I. Electrical Load Data

Not applicable.

J. References

1. Existing Data:

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

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ALERT ALERT
b. Boeing Service Related Problem (SRP) 737-SRP-53-0381.

c. Federal Aviation Administration (FAA) Airworthiness Directive (AD) 2008-08-23, 2008-09-13,

98-11-04 R1.

d. Service Bulletin Index D6-19567.

e. D6-38669 Repair Assessment Guidelines (RAG) -Model 737-100 to -500.

f. Standard Overhaul Practices Manual (SOPM) 20-41-02, 20-43-03, 20-50-19.

g. 737 Fleet Team Digest (FTD) 53-11003.

h. 737 Non-Destructive Testing (NDT) Manual Part 6, 51-00-00, Part 6, 51-00-26, Part 6, 53-30-00.

i. 737-100/200 Aircraft Maintenance Manual (AMM) 25-21-31, 25-21-41.

j. 737-300/400/500 Aircraft Maintenance Manual (AMM) 25-21-31.

k. 737-100/200 Structural Repair Manual (SRM) 51-30-08

l. 737-300 Structural Repair Manual (SRM) 51-40-08, 53-10-01.

m. 737-400 Structural Repair Manual (SRM) 51-40-08, 53-10-01.

n. 737-500 Structural Repair Manual (SRM) 51-40-08, 53-10-01.

2. Data Supplied with this Service Bulletin:

a. Drawings:

Drawing No Title Sheet DCN/REV ADCN

Repair and Preventive Modification, Upper 1 - -

Forward Entry Doorway - Kit

65C36941

2 - -

PL - 1, 2

PSDL A -

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

None.

Boeing Process Specifications referred to on drawings are not given in this service bulletin since

these procedures are frequently used as standard shop practices.

K. Publications Affected

1. Publications:

None.

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ALERT ALERT
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. DTI requirements for the structure affected

are contained in Paragraph 1.E., Compliance of this service bulletin.

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
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BLANK PAGE
2. MATERIAL INFORMATION

A. Material - Price and Availability

Group 1-2, Configuration 1; Group 3-4:

None.

Group 1-2, Configuration 2:

Boeing can supply the kits shown in Paragraph 2.C., Parts Necessary for Each Airplane. Operators

are encouraged to share schedule requirements with Boeing for incorporation of the service bulletin.

The kits are subject to the terms and conditions of the Boeing standard purchase order acknowledgment.

Prices are in United States Dollars. Terms: Net 30 days.

Group 1-2, Configuration 2:

Reference this service bulletin and submit your purchase order by one of these methods:

Group 1-2, Configuration 2:

1. Order on-line via ATA Spec 2000 or The Boeing PART Page

2. Fax to (206) 662-7145

Group 1-2, Configuration 2:

REFER TO THE BOEING PART PAGE ON MYBOEINGFLEET.COM OR CONTACT FIRST RESPONDER

AT FR@BOEING.COM FOR THE LATEST REORDER LEAD TIME (ROLT) AND PRICE INFORMATION

Unit Price as of

the Revision 1

date of this Service Bulletin (US

Dollars)

ROLT as of the

original issue

date of this Service Bulletin

(Weeks)

Kit Number Name

65C36941-1 Kit - Preventive Modification 25 $2222.00

65C36941-5 Kit - Repair 25 $2527.00

65C36941-7 Kit - Repair 25 $4573.00

65C36941-13 Kit - Preventive Modification 25 $3912.00

65C36941-15 Kit - Repair 25 $4103.00

65C36941-17 Kit - Repair 25 $4964.00

B. Industry Support Information

Boeing warranty remedies are not available for the inspection, and/or repair/preventive modification

procedures given in this service bulletin.

C. Parts Necessary for Each Airplane

1. Kits/Parts

Group 1-2, Configuration 1; Group 3-4:

None.

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ALERT ALERT
Group 1-2, Configuration 2:

To get the kits/parts shown below, refer to Paragraph 2.A., Material - Price and Availability.

Group 1-2, Configuration 2:

NOTE: One top kit and the items shown in Paragraph 2.C.2., Parts and Materials Supplied by

the Operator, are necessary for each airplane.

Group 1, Configuration 2:

Kit 65C36941 Upper Forward Entry Doorway - Repair and Preventive Modification

Part Number QTY Name Notes

-1 -5 -7

PREVENTIVE MODIFICATION65C36941-1 - . . REPAIR INSTL

65C36941-5 . - . REPAIR INSTL (a)

65C36941-7 . . - REPAIR INSTL (b)

65C36941-2 1 1 . STOCK DOUBLER (c)

65C36941-3 1 1 . DOUBLER (c)

65C36941-4 . 1 . STOCK TRIPLER (d)

65C36941-6 . 1 . TRIPLER (d)

65C36941-8 . . 1 STOCK DOUBLER (e)

65C36941-9 . . 1 DOUBLER (e)

65C36941-10 . . 1 STOCK TRIPLER (f)

65C36941-11 . . 1 TRIPLER (f)

66-2955-40 250 250 250 WASHER, REPAIR (g)

66-2955-41 5 5 5 WASHER, REPAIR (g)

66-2955-47 50 50 50 WASHER, REPAIR (g)

BACB30NW6K10X 6 3 14 HI-LOK, 3/16 DIA (g) (h)

BACB30NW6K11X . 4 . HI-LOK, 3/16 DIA (g) (h)

BACB30NW6K13X . . 3 HI-LOK, 3/16 DIA (g) (h)

BACB30NW6K3X 3 3 3 HI-LOK, 3/16 DIA (g) (h)

BACB30NW6K4X 76 42 3 HI-LOK, 3/16 DIA (g) (h)

BACB30NW6K5X 50 57 50 HI-LOK, 3/16 DIA (g) (h)

BACB30NW6K6X 40 35 12 HI-LOK, 3/16 DIA (g) (h)

BACB30NW6K7X 34 60 34 HI-LOK, 3/16 DIA (g) (h)

BACB30NW6K8X 3 14 54 HI-LOK, 3/16 DIA (g) (h)

BACB30NW6K9X . . 40 HI-LOK, 3/16 DIA (g) (h)

BACB30NW8K8X 5 5 5 HI-LOK, 1/4 DIA (g) (h)

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ALERT ALERT
Group 1, Configuration 2:

Kit 65C36941 Upper Forward Entry Doorway - Repair and Preventive Modification

Part Number QTY Name Notes

-1 -5 -7

BACB30VU6K2 6 5 . HI-LOK, 3/16 DIA (g) (h)

BACB30VU6K3 58 58 62 HI-LOK, 3/16 DIA (g) (h)

BACB30VU6K4 54 28 . HI-LOK, 3/16 DIA (g) (h)

BACB30VU6K5 3 20 28 HI-LOK, 3/16 DIA (g) (h)

BACB30VU6K6 . 2 2 HI-LOK, 3/16 DIA (g) (h)

BACB30VU6K7 . . 20 HI-LOK, 3/16 DIA (g) (h)

BACC30BL6 114 114 114 COLLAR (g)

BACC30M6 220 220 220 COLLAR (g)

BACC30M8 5 5 5 COLLAR (g)

BACF3F010J175NN 1 1 1 FILLER

BACF3F010J225NN . 1 1 FILLER

BACR15BB4D10 . . 2 RIVET (g) (h)

BACR15BB4D5 3 . . RIVET (g) (h)

BACR15BB4D6 2 3 . RIVET (g) (h)

BACR15BB4D8 . 2 . RIVET (g) (h)

BACR15BB4D9 . . 3 RIVET (g) (h)

BACR15BB5D11 . . 4 RIVET (g) (h)

BACR15BB5D5 2 . . RIVET (g) (h)

BACR15BB5D7 4 2 . RIVET (g) (h)

BACR15CE5D9 . 4 2 RIVET (g) (h)

BACR15CE6D10 . 3 . RIVET (g) (h)

BACR15CE6D11 . . 34 RIVET (g) (h)

BACR15CE6D12 . . 3 RIVET (g) (h)

BACR15CE6D7 33 4 . RIVET (g) (h)

BACR15CE6D8 9 36 10 RIVET (g) (h)

BACR15CE6D9 3 4 . RIVET (g) (h)

BACW10BN3AP 50 50 50 WASHER (i)

BACW10BN31AP 100 100 100 WASHER (i)

BACW10BN41AP 10 10 10 WASHER (i)

(a) For repair use if crack is in skin assembly but there are no cracks in the bearstrap.

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BOEING SERVICE BULLETIN 737-53A1163

ALERT ALERT
Group 1, Configuration 2:

Kit 65C36941 Upper Forward Entry Doorway - Repair and Preventive Modification

Part Number QTY Name Notes

-1 -5 -7

(b) For repair use if crack is in skin assembly and bearstrap.

(c) 65C36941-2 is used to make 65C36941-3.

(d) 65C36941-4 is used to make 65C36941-6.

(e) 65C36941-8 is used to make 65C36941-9.

(f) 65C36941-10 is used to make 65C36941-11.

(g) There are more parts than are necessary.

(h) If grip length shown is not available at Boeing, fasteners supplied in kits may be one grip length longer

than indicated. Also, if any fasteners part numbers listed are not available or have been superseded,

substitute fasteners may be supplied in kits.

(i) Use if required to bring material thickness within bolt grip range. Maximum of (2) washers allowed.

Group 2, Configuration 2:

Kit 65C36941 Upper Forward Entry Doorway - Repair and Preventive Modification

Part Number QTY Name Notes

-13 -15 -17

PREVENTIVE MODIFICATION65C36941-13 - . . REPAIR INSTL

65C36941-15 . - . REPAIR INSTL (a)

65C36941-17 . . - REPAIR INSTL (b)

65C36941-8 1 1 1 STOCK DOUBLER (c)

65C36941-14 1 1 1 DOUBLER (c)

65C36941-4 . 1 . STOCK TRIPLER (d)

65C36941-16 . 1 . TRIPLER (d)

65C36941-18 . . 1 TRIPLER (e)

65C36941-10 . . 1 STOCK TRIPLER (e)

66-2955-11 10 10 10 WASHER, REPAIR (f)

66-2955-40 250 250 250 WASHER, REPAIR (f)

66-2955-41 20 20 20 WASHER, REPAIR (f)

66-2955-47 50 50 50 WASHER, REPAIR (f)

BACB30NW6K10X 16 8 12 HI-LOK, 3/16 DIA (f) (g)

BACB30NW6K11X 4 12 14 HI-LOK, 3/16 DIA (f) (g)

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BOEING SERVICE BULLETIN 737-53A1163

ALERT ALERT
Group 2, Configuration 2:

Kit 65C36941 Upper Forward Entry Doorway - Repair and Preventive Modification

Part Number QTY Name Notes

-13 -15 -17

BACB30NW6K12X . . 8 HI-LOK, 3/16 DIA (f) (g)

BACB30NW6K4X 3 3 3 HI-LOK, 3/16 DIA (f) (g)

BACB30NW6K5X 50 22 22 HI-LOK, 3/16 DIA (f) (g)

BACB30NW6K6X 66 48 20 HI-LOK, 3/16 DIA (f) (g)

BACB30NW6K7X 90 108 62 HI-LOK, 3/16 DIA (f) (g)

BACB30NW6K8X 17 34 63 HI-LOK, 3/16 DIA (f) (g)

BACB30NW6K9X 4 14 47 HI-LOK, 3/16 DIA (f) (g)

BACB30NW8K7X 9 9 9 HI-LOK, 1/4 DIA (f) (g)

BACB30NW8K8X 4 4 4 HI-LOK, 1/4 DIA (f) (g)

BACB30NW8K9X 3 3 3 HI-LOK, 1/4 DIA (f) (g)

BACB30VU6K3 24 22 21 HI-LOK, 3/16 DIA (f) (g)

BACB30VU6K4 16 18 16 HI-LOK, 3/16 DIA (f) (g)

BACB30VU6K5 38 29 30 HI-LOK, 3/16 DIA (f) (g)

BACB30VU6K6 3 12 4 HI-LOK, 3/16 DIA (f) (g)

BACB30VU6K7 2 2 2 HI-LOK, 3/16 DIA (f) (g)

BACB30VU6K8 . . 10 HI-LOK, 3/16 DIA (f) (g)

BACC30BL6 84 84 84 COLLAR (f)

BACC30M6 250 250 250 COLLAR (f)

BACC30M8 16 16 16 COLLAR (f)

BACF3F010M175NN 1 1 1 FILLER

BACF3F010J225NN . 1 . FILLER

BACF3F010V225NN . . 1 FILLER

BACR15BB4D11 . . 2 RIVET (f) (g)

BACR15BB4D6 3 . . RIVET (f) (g)

BACR15BB4D7 . 3 RIVET (f) (g)

BACR15BB4D8 2 . . RIVET (f) (g)

BACR15BB4D9 . 2 3 RIVET (f) (g)

BACR15BB5D11 . . 5 RIVET (f) (g)

BACR15BB5D8 5 RIVET (f) (g)

BACR15BB5D9 . 5 RIVET (f) (g)

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BOEING SERVICE BULLETIN 737-53A1163

ALERT ALERT
Group 2, Configuration 2:

Kit 65C36941 Upper Forward Entry Doorway - Repair and Preventive Modification

Part Number QTY Name Notes

-13 -15 -17

BACR15CE6D10 . 3 . RIVET (f) (g)

BACR15CE6D11 . . 32 RIVET (f) (g)

BACR15CE6D8 36 7 7 RIVET (f) (g)

BACR15CE6D9 3 29 . RIVET (f) (g)

BACR15DS7D10 9 7 6 RIVET (f) (g)

BACR15DS7D11 . 4 2 RIVET (f) (g)

BACR15DS7D13 . . 4 RIVET (f) (g)

BACR15DS7D9 2 . . RIVET (f) (g)

BACW10BN3AP 50 50 50 WASHER (h)

BACW10BN31AP 100 100 100 WASHER (h)

BACW10BN41AP 10 10 10 WASHER (h)

(a) For repair use if crack is in skin assembly but there are no cracks in the bearstrap.

(b) For repair use if crack is in skin assembly and bearstrap.

(c) 65C36941-8 is used to make 65C36941-14.

(d) 65C36941-4 is used to make 65C36941-16.

(e) 65C36941-10 is used to make 65C36941-18.

(f) There are more parts than are necessary.

(g) If grip length shown is not available at Boeing, fasteners supplied in kits may be one grip length longer

than indicated. Also, if any fasteners part numbers listed are not available or have been superseded,

substitute fasteners may be supplied in kits.

(h) Use if required to bring material thickness within bolt grip range. Maximum of (2) washers allowed.

2. Parts and Materials Supplied by the Operator

Group 1-2, Configuration 1; Group 4:

None.

Group 1-2, Configuration 2:

The following parts or materials are necessary to do the change in this service bulletin. Parts and

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

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

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BOEING SERVICE BULLETIN 737-53A1163

ALERT ALERT
Group 1-2, Configuration 2:

Part Number / QTY Name Notes

Specification

BMS 5-95, Class 8 Oz Sealant (a)

B-1/2, -2 or -4

(a) Refer to the Qualified Products List at the end of the Boeing Material Specification (BMS)

for supplier data.

Group 3:

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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Export Controlled ECCN: 9E991 - BOEING

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BOEING SERVICE BULLETIN 737-53A1163

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 limits to tighten nuts and bolts are in SRM Chapter 51

4. Use the approved fastener and process material substitutions in accordance with

SRM Chapter 51.

5. Refer to 737-100/200 SRM 51-30-08, or 737-300 SRM 51-40-08, or 737-400 SRM

51-40-08, or 737-500 SRM 51-40-08 for countersink instructions and instructions on

how to install countersink repair washers.

6. Refer to the SOPM 20-50-11 for application of aerodynamic smoother.

7. 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.

8. 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.

9. 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.

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BOEING SERVICE BULLETIN 737-53A1163

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10. 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.

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. Some Boeing parts are supplied in a temporary configuration. Those parts are

identified with a 'U', 'W', or 'Y' in place of the '-' (dash) in the part number. It is

permitted to install parts identified with a 'U', 'W', or 'Y' as an alternative to the '-'

(dash) part number. Boeing Drawing 005W0900 contains more data.

14. Shaded areas in Figures are reference only. Shaded areas in Figures may look

different than your airplane.

B. WORK INSTRUCTIONS

1. Group 4:

Contact Boeing to get instructions for the inspection and/or repair for this service bulletin,

737-53A1163 Revision 1, and do the work instructed by Boeing.

2. Group 1-2, Configuration 1:

Airplanes with the repair or preventive modification installed in accordance with the original issue

of this SB are not required to be inspected in accordance with the SB. Post repair/preventive

modification inspections are provided in Table 3 of Paragraph 1.E., Compliance.

3. Group 1-2, Configuration 2; Group 3:

Do Parts 1, 2 and 3 as applicable. Refer to Paragraph 1.E., Compliance.

4. Group 1-3:

For door corners that have a repair provided by Boeing and approved via FAA Form 8100-9

installed, the inspection in this SB is not required for the repaired door corner(s). Refer to the repair

approval for any supplemental inspection of the repair area.

Group 1-2, Configuration 2; Group 3:

PART 1 - INSPECTION

1. Get external access to the upper corners of the forward entry doorway.

2. Group 1, Configuration 2; Group 3:

Do an external detailed inspection of the skin assembly and a Low Frequency Eddy Current (LFEC)

inspection of the skin assembly and bearstrap for any crack in accordance with FIGURE 2.

a. If any crack is found, do Part 3 - Repair.

b. If no cracks are found, do Part 2 - Preventive Modification or do repeat inspections at the

times given in Paragraph 1.E., Compliance.

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ALERT ALERT
3. Group 2, Configuration 2:

Do an external detailed inspection of the skin assembly and a LFEC inspection of the skin assembly

and bearstrap for any crack in accordance with FIGURE 3.

a. If any crack is found, do Part 3 - Repair.

b. If no cracks are found, do Part 2 - Preventive Modification or do repeat inspections at the

times given in Paragraph 1.E., Compliance.

4. Put the airplane back to a serviceable condition.

Group 1-2, Configuration 2; Group 3:

PART 2 - PREVENTIVE MODIFICATION

1. Get access to the passenger cabin side of the forward entry doorway upper corners by removing

the sidewall lining panels. Refer to 737-100/200 AMM 25-21-41 and 737-100/200 AMM 25-21-31

or 737-300/400/500 AMM 25-21-31 as an accepted procedure.

2. Group 1, Configuration 2:

Install the preventive modification (Kit 65C36941-1) in accordance with 65C36941 Sheet 1 and

Sheet PSDL and general repair notes given below.

– Remove all fasteners common to the preventive modification area. At all open holes common

to the preventive modification area, do fastener hole probe inspection in accordance with 737

NDT Manual Part 6, 51-00-00, Figure 16.

– Make sure that all repair parts and machine surfaces have a minimum of 63 RMS finish or

better. This requirement supersedes the 125 RMS for all machine surfaces of 65C36941

PSDL, General Note 1.

– Maintain a minimum 2D edge margin on all repair parts except for repair filler. Maintain a

minimum 1.5D edge margin on fillers.

– Install all rivets dry and over-driven to a minimum of 1.4D driven head. Install all hex-drive

bolts wet with BMS 5-95 sealant in transition fit holes.

– Prior to clamp up, shim all gaps greater than 0.01 inches up to a maximum of 0.04 inches.

Contact Boeing for any gap greater than 0.04 inches.

– Install all parts wet with faying surface seal BMS 5-95 sealant. Refer to SOPM 20-50-19 as

an acceptable procedure.

NOTE: Accomplishment of the preventive modification in accordance with the above noted repair

terminates the inspection requirements in Table 1 of Paragraph 1.E., Compliance. Post

preventive modification inspections are provided in Table 3 of Paragraph 1.E., Compliance.

3. Group 2, Configuration 2:

Install the preventive modification (Kit 65C36941-13) in accordance with 65C36941 Sheet 2 and

Sheet PSDL and general repair notes given below.

– Remove all fasteners common to the preventive modification area. At all open holes common

to the preventive modification area, do fastener hole probe inspection in accordance with 737

NDT Manual Part 6, 51-00-00, Figure 16.

– Make sure that all repair parts and machine surfaces have a minimum of 63 RMS finish or

better. This requirement supersedes the 125 RMS for all machine surfaces of 65C36941

PSDL, General Note 1.

– Maintain a minimum 2D edge margin on all repair parts except for repair filler. Maintain a

minimum 1.5D edge margin on fillers.

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ALERT ALERT
– Install all rivets dry and over-driven to a minimum of 1.4D driven head. Install all hex-drive

bolts wet with BMS 5-95 sealant in transition fit holes.

– Prior to clamp up, shim all gaps greater than 0.01 inches up to a maximum of 0.04 inches.

Contact Boeing for any gap greater than 0.04 inches.

– Install all parts wet with faying surface seal BMS 5-95 sealant. Refer to SOPM 20-50-19 as

an acceptable procedure.

NOTE: Accomplishment of the preventive modification in accordance with the above noted repair

terminates the inspection requirements in Table 3 of Paragraph 1.E., Compliance. Post

preventive modification inspections are provided in Table 3 of Paragraph 1.E., Compliance.

4. Group 3:

Install the preventive modification in accordance with 737-300 SRM 53-10-01 Repair 22, or 737-400

SRM 53-10-01 Repair 22, or 737-500 SRM 53-10-01 Repair 22.

NOTE: Accomplishment of the preventive modification in accordance with the above noted repair

terminates the inspection requirements of this service bulletin. Post preventive modification

inspections are provided in the applicable SRM.

5. Install the forward entry doorway sidewall lining panels that were removed. Refer to 737-100/200

AMM 25-21-41 and 737-100/200 AMM 25-21-31 or 737-300/400/500 AMM 25-21-31 as an accepted

procedure.

6. Put the airplane back to a serviceable condition.

Group 1-2, Configuration 2; Group 3:

PART 3 - REPAIR

1. Get access to the passenger cabin side of the forward entry doorway upper corners by removing

the sidewall lining panels. Refer to 737-100/200 AMM 25-21-41 and 737-100/200 AMM 25-21-31

or 737-300/400/500 AMM 25-21-31 as an accepted procedure.

2. Group 1, Configuration 2:

Do as follows:

a. Cut out all cracks found in accordance with FIGURE 4.

NOTE: Stop drill to terminate a crack is no longer an accepted procedure.

b. Remove all the fasteners common to the repair area. At all open fastener holes common to

the repair area, do an HFEC hole probe inspection for any crack in accordance with 737 NDT

Manual Part 6, 51-00-00, Figure 16. If any crack is found, contact Boeing for repair instructions

and do the work instructed by Boeing.

c. If any crack is found outside the maximum cutout area or if the cutout area is larger than then

maximum cutout area allowed, contact Boeing for instructions and do the work instructed by

Boeing.

d. If cutout in only in the skin assembly but not in the bearstrap, install the repair (Kit 65C36941-5)

in accordance with 65C36941 Sheet 1 and Sheet PSDL and general notes below.

e. If cutout is in the skin assembly and the bearstrap, install the repair (Kit 65C36941-7) in

accordance with 65C36941 Sheet 1 and Sheet PSDL and general notes below.

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f. General repair notes:

– Make sure that all repair parts and machine surfaces have a minimum of 63 RMS finish

or better. This requirement supersedes the 125 RMS for all machine surfaces of 65C36941

PSDL, General Note 1.

– Maintain a minimum 2D edge margin on all repair parts except for repair filler. Maintain

a minimum 1.5D edge margin on fillers.

– Install all rivets dry and over-driven to a minimum of 1.4D driven head. Install all hex-drive

bolts wet with BMS 5-95 sealant in transition fit holes.

– Prior to clamp up, shim all gaps greater than 0.01 inches up to a maximum of 0.04 inches.

Contact Boeing for any gap greater than 0.04 inches.

– Install all parts wet with faying surface seal BMS 5-95 sealant. Refer to SOPM 20-50-19

as an acceptable procedure.

g. Accomplishment of the repairs in accordance with the procedure above terminates the

inspection requirements of Table 1 of Paragraph 1.E., Compliance. Post repair inspections

are provided in Table 3 of Paragraph 1.E., Compliance.

3. Group 2, Configuration 2:

Do as follows:

a. Cut out all cracks found in accordance with FIGURE 5.

NOTE: Stop drill to terminate a crack is no longer an accepted procedure.

b. Remove all the fasteners common to the repair area. At all open fastener holes common to

the repair, do an HFEC hole probe inspection for any crack in accordance with 737 NDT

Manual Part 6, 51-00-00, Figure 16.

c. If any crack is found outside the maximum cutout area or if the cutout area is larger than then

maximum cutout area allowed, contact Boeing for instructions and do the work instructed by

Boeing.

d. If cutout in only in the skin assembly but not in the bearstrap, install the repair (Kit

65C36941-15) in accordance with 65C36941 Sheet 1 and Sheet PSDL and general notes

below.

e. If cutout is in the skin assembly and the bearstrap, install the repair (Kit 65C36941-17) in

accordance with 65C36941 Sheet 1 and Sheet PSDL and general notes below.

f. General repair notes:

– Make sure that all repair parts and machine surfaces have a minimum of 63 RMS finish

or better. This requirement supersedes the 125 RMS for all machine surfaces of 65C36941

PSDL, General Note 1.

– Maintain a minimum 2D edge margin on all repair parts except for repair filler. Maintain

a minimum 1.5D edge margin on fillers.

– Install all rivets dry and over-driven to a minimum of 1.4D driven head. Install all hex-drive

bolts wet with BMS 5-95 sealant in transition fit holes.

– Prior to clamp up, shim all gaps greater than 0.01 inches up to a maximum of 0.04 inches.

Contact Boeing for any gap greater than 0.04 inches.

– Install all parts wet with faying surface seal BMS 5-95 sealant. Refer to SOPM 20-50-19

as an acceptable procedure.

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g. Accomplishment of the repairs in accordance with the procedure above terminates the

inspection requirements of Table 1 of Paragraph 1.E., Compliance. Post repair inspections

are provided in Table 3 of Paragraph 1.E., Compliance.

4. Group 3:

Do as follows:

a. If any crack is found in the forward upper corner of the doorway but there are no cracks at

the aft upper corner, install the repair in accordance with the applicable 737-300 SRM 53-10-01

Repair 17, or 737-400 SRM 53-10-01 Repair 17, or 737-500 SRM 53-10-01 Repair 17.

NOTE: As an option, in addition to the repair, install the preventive portion for the aft upper

corner in accordance with the applicable 737-300 SRM 53-10-01 Repair 17, or

737-400 SRM 53-10-01 Repair 17, or 737-500 SRM 53-10-01 Repair 17.

b. If any crack is found in the aft upper corner of the doorway but there are no cracks at the

forward upper corner, install the repair in accordance with the applicable 737-300 SRM

53-10-01 Repair 21, or 737-400 SRM 53-10-01 Repair 21, or 737-500 SRM 53-10-01 Repair

21.

NOTE: As an option, in addition to the repair, install the preventive portion for the forward

upper corner in accordance with the applicable 737-300 SRM 53-10-01 Repair 21,

or 737-400 SRM 53-10-01 Repair 21, or 737-500 SRM 53-10-01 Repair 21.

c. If any crack is found in the forward and aft upper corner of the doorway, install the repair in

accordance with the applicable 737-300 SRM 53-10-01 Repair 22, or 737-400 SRM 53-10-01

Repair 22, or 737-500 SRM 53-10-01 Repair 22.

d. Accomplishment of the repairs or preventive modification in accordance with the applicable

SRM terminates the inspection requirements of this service bulletin in the modified area. Post

repair inspections are provided in the applicable SRM.

5. Install the forward entry doorway sidewall lining panels that were removed. Refer to 737-100/200

AMM 25-21-41 and 737-100/200 AMM 25-21-31 or 737-300/400/500 AMM 25-21-31 as an accepted

procedure.

6. Put the airplane back to a serviceable condition.

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FIGURE 1: THIS FIGURE WAS DELETED AT REVISION 1

(SHEET 1 OF 1)

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BOEING SERVICE BULLETIN 737-53A1163

ALERT ALERT
This Figure applies only to: Group 1, Configuration 2; Group 3.

FIGURE 2: FORWARD ENTRY DOORWAY - BEARSTRAP AND SKIN ASSEMBLY - INSPECTION

(SHEET 1 OF 4)

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FIGURE 2: FORWARD ENTRY DOORWAY - BEARSTRAP AND SKIN ASSEMBLY - INSPECTION

(SHEET 2 OF 4)

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FIGURE 2: FORWARD ENTRY DOORWAY - BEARSTRAP AND SKIN ASSEMBLY - INSPECTION

(SHEET 3 OF 4)

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BOEING SERVICE BULLETIN 737-53A1163

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 Assembly - - (a)

Skin Assembly and - - (b)

Bearstrap

2 Inspect

(a) Do an external detailed inspection for any crack in the Skin Assembly in the area shown.

(b) Do an external Low Frequency Eddy Current (LFEC) inspection around the fastener head for any crack

in the skin assembly and bear strap in accordance with 737 NDT Manual Part 6, 51-00-26.

FIGURE 2: FORWARD ENTRY DOORWAY - BEARSTRAP AND SKIN ASSEMBLY - INSPECTION

(SHEET 4 OF 4)

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BOEING SERVICE BULLETIN 737-53A1163

ALERT ALERT
This Figure applies only to: Group 2, Configuration 2.

FIGURE 3: FORWARD ENTRY DOORWAY - BEARSTRAP AND SKIN ASSEMBLY - INSPECTION

(SHEET 1 OF 4)

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BOEING SERVICE BULLETIN 737-53A1163

ALERT ALERT
FIGURE 3: FORWARD ENTRY DOORWAY - BEARSTRAP AND SKIN ASSEMBLY - INSPECTION

(SHEET 2 OF 4)

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BOEING SERVICE BULLETIN 737-53A1163

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FIGURE 3: FORWARD ENTRY DOORWAY - BEARSTRAP AND SKIN ASSEMBLY - INSPECTION

(SHEET 3 OF 4)

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BOEING SERVICE BULLETIN 737-53A1163

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 Assembly - - (a)

Skin Assembly and - - (b)

Bearstrap

2 Inspect

(a) Do an external detailed inspection for any crack in the Skin Assembly in the area shown.

(b) Do an external Low Frequency Eddy Current (LFEC) inspection around the fastener head for any crack

in the skin assembly and bearstrap in accordance with 737 NDT Manual Part 6, 51-00-26.

FIGURE 3: FORWARD ENTRY DOORWAY - BEARSTRAP AND SKIN ASSEMBLY - INSPECTION

(SHEET 4 OF 4)

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BOEING SERVICE BULLETIN 737-53A1163

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

FIGURE 4: FORWARD ENTRY DOORWAY - BEARSTRAP AND SKIN ASSEMBLY - CRACK REMOVAL

(SHEET 1 OF 4)

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BOEING SERVICE BULLETIN 737-53A1163

ALERT ALERT
FIGURE 4: FORWARD ENTRY DOORWAY - BEARSTRAP AND SKIN ASSEMBLY - CRACK REMOVAL

(SHEET 2 OF 4)

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BOEING SERVICE BULLETIN 737-53A1163

ALERT ALERT
FIGURE 4: FORWARD ENTRY DOORWAY - BEARSTRAP AND SKIN ASSEMBLY - CRACK REMOVAL

(SHEET 3 OF 4)

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BOEING SERVICE BULLETIN 737-53A1163

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 Cut Skin Assembly - - (a)

Cut Bearstrap - - (a)

2 Inspect Cutout - - (b)

Skin Assembly (As Re- - - (c)

quired)

3 Cut

Bearstrap (As Re- - - (c)

quired)

Cut

4 Make Filler 2024-T3 - (d) (e)

Chemical Conversion TYPE 2, CLASS A - (e)

Coating

5 Apply

Apply Primer BMS10-11, TYPE 1 - (f)

(a) Cut out the skin assembly and/or bearstrap as required to remove all damages. Maintain a minimum 0.5

inch radius. If the cut out exceeds the maximum dimension shown, contact Boeing for repair and do the

repair. Maintain 2D edge margin to adjacent fasteners. For skin and bonded doubler assemblies, cut both

skin and doubler together.

(b) Do a High Frequency Eddy Current (HFEC) inspection of the cutout for any crack in accordance with 737

NDT Manual Part 6, 51-00-00, Figure 4 or Figure 23.

(c) If any crack is found, re-accomplish Step 1. If there are no crack indications, oversize the cutout by 0.04

inches minimum. Maintain a minimum of 63 RMS finish on the cutout and a 2D minimum edge margin

for adjacent fasteners. If the cut out exceeds the maximum dimension shown, contact Boeing for repair

and do the repair.

(d) Size of filler to be determined by size of cutout and thickness of filler to be determined by build up of repair

thickness at the crack location.

(e) Apply chemical conversion coating to the edge of the cutout and the filler. Refer to SOPM 20-43-03 as

an accepted procedure.

(f) Apply two coats of primer BMS 10-11, Type 1 to the edge of the cutout and the filler. Refer to SOPM 20-

41-02 as an accepted procedure.

FIGURE 4: FORWARD ENTRY DOORWAY - BEARSTRAP AND SKIN ASSEMBLY - CRACK REMOVAL

(SHEET 4 OF 4)

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BOEING SERVICE BULLETIN 737-53A1163

ALERT ALERT
This Figure applies only to: Group 2, Configuration 2.

FIGURE 5: FORWARD ENTRY DOORWAY - BEARSTRAP AND SKIN ASSEMBLY - CRACK REMOVAL

(SHEET 1 OF 4)

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FIGURE 5: FORWARD ENTRY DOORWAY - BEARSTRAP AND SKIN ASSEMBLY - CRACK REMOVAL

(SHEET 2 OF 4)

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FIGURE 5: FORWARD ENTRY DOORWAY - BEARSTRAP AND SKIN ASSEMBLY - CRACK REMOVAL

(SHEET 3 OF 4)

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BOEING SERVICE BULLETIN 737-53A1163

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 Cut Skin Assembly - - (a)

Cut Bearstrap - - (a)

2 Inspect Cutout - - (b)

Skin Assembly (As Re- - - (c)

quired)

3 Cut

Bearstrap (As Re- - - (c)

quired)

Cut

4 Make Filler 2024-T3 - (d) (e)

Chemical Conversion TYPE 2, CLASS A - (e)

Coating

5 Apply

Apply Primer BMS10-11, TYPE 1 - (f)

(a) Cut out the skin assembly and/or bearstrap as required to remove all damages. Maintain a minimum 0.5

inch radius. If the cut out exceeds the maximum dimension shown, contact Boeing for repair and do the

repair. Maintain 2D edge margin to adjacent fasteners. For skin and bonded doubler assemblies, cut both

skin and doubler together.

(b) Do a High Frequency Eddy Current (HFEC) inspection of the cutout for any crack in accordance with 737

NDT Manual Part 6, 51-00-00, Figure 4 or Figure 23.

(c) If any crack is found, re-accomplish Step 1. If there are no crack indications, oversize the cutout by 0.04

inches minimum. Maintain a minimum of 63 RMS finish on the cutout and a 2D minimum edge margin

for adjacent fasteners. If the cut out exceeds the maximum dimension shown, contact Boeing for repair

and do the repair.

(d) Size of filler to be determined by size of cutout and thickness of filler to be determined by build up of repair

thickness at the crack location.

(e) Apply chemical conversion coating to the edge of the cutout and the filler. Refer to SOPM 20-43-03 as

an accepted procedure.

(f) Apply two coats of primer BMS 10-11, Type 1 to the edge of the cutout and the filler. Refer to SOPM 20-

41-02 as an accepted procedure.

FIGURE 5: FORWARD ENTRY DOORWAY - BEARSTRAP AND SKIN ASSEMBLY - CRACK REMOVAL

(SHEET 4 OF 4)

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BOEING SERVICE BULLETIN 737-53A1163

ALERT ALERT