Commercial 

Airplanes 737

Service Bulletin

Number: 737-53-1058

Original Issue: April 04, 1980

Revision 4: January 09, 2014

ATA System: 5313

SUBJECT: FUSELAGE - Forward Airstair Stowage Doorway Inspection, Preventive 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 © 1989 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Unpublished Work.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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4.0
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BOEING SERVICE BULLETIN 737-53-1058

BLANK PAGE
Table of Contents

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

Summary ...................................................... 7

1. PLANNING INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

A. Effectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

1. Airplanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

B. Concurrent Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

C. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

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

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

F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

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

I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

1. Existing Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

2. Data Supplied with this Service Bulletin: . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

3. Installation Drawings Used in the Preparation of this Service Bulletin: . . . . . . . . . . . 36

K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

M. Software Accomplishment Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

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

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

B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

C. Parts Necessary for Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

1. Kits/Parts: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

2. Parts and Materials Supplied by the Operator: . . . . . . . . . . . . . . . . . . . . . . . . 41

3. Parts Modified and Reidentified: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

4. Parts Removed and Not Replaced: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

D. Parts Necessary to Change Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

E. Special Tooling - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

F. Special Tooling Necessary to do this Service Bulletin . . . . . . . . . . . . . . . . . . . . . . . 41

3. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

B. WORK INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

FIGURE 1: THIS FIGURE HAS BEEN REMOVED . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

FIGURE 2: THIS FIGURE HAS BEEN REMOVED . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

FIGURE 3: THIS FIGURE HAS BEEN REMOVED . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

FIGURE 4: AIRSTAIR STOWAGE DOORWAY CORNER - LOCATION OF INSPECTION AREAS [Group

1-5] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

FIGURE 5: AIRSTAIR STOWAGE DOORWAY CORNER - INTERNAL INSPECTION OF THE BEARSTRAP

[Group 1-5] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

FIGURE 6: AIRSTAIR STOWAGE DOORWAY CORNER INSPECTION - NO PREVENTIVE MODIFICATION

OR EXTERNAL TRIPLER INSTALLED [Group 1-2] . . . . . . . . . . . . . . . . . . . . . 62

FIGURE 7: AIRSTAIR STOWAGE DOORWAY CORNER INSPECTION - PREVENTIVE MODIFICATION

TRIPLER INSTALLED PER ORIGINAL ISSUE OF THIS SERVICE BULLETIN [Group 1-2] . 64

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BOEING SERVICE BULLETIN 737-53-1058
FIGURE 8: AIRSTAIR STOWAGE DOORWAY CORNER INSPECTION - PREVENTIVE MODIFICATION

TRIPLER INSTALLED PER REVISION 1, 2 OR 3 OF THIS SERVICE BULLETIN [Group 1-2]

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

FIGURE 9: AIRSTAIR STOWAGE DOORWAY CORNER INSPECTION - PRODUCTION MODIFICATION

EXTERNAL TRIPLER INSTALLED [Group 3-5] . . . . . . . . . . . . . . . . . . . . . . . 68

FIGURE 10: AIRSTAIR STOWAGE DOORWAY CORNER INSPECTION - REPAIR INSTALLED AT THE

ORIGINAL ISSUE OF THIS SERVICE BULLETIN [Group 1] . . . . . . . . . . . . . . . . 70

FIGURE 11: AIRSTAIR STOWAGE DOORWAY CORNER INSPECTION - REPAIR INSTALLED AT THE

ORIGINAL ISSUE OF THIS SERVICE BULLETIN [Group 2] . . . . . . . . . . . . . . . . 73

FIGURE 12: AIRSTAIR STOWAGE DOORWAY CORNER - AREA OF CUTOUT FOR CRACK REMOVAL

[Group 1-5] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

FIGURE 13: POST REPAIR AND POST PREVENTIVE MODIFICATION INSPECTION - OPTION A [Group

1-5] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

FIGURE 14: POST REPAIR AND POST PREVENTIVE MODIFICATION INSPECTION - OPTION B [Group

1-5] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

Export Controlled ECCN: 9E991 - BOEING

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BOEING SERVICE BULLETIN 737-53-1058
Commercial 

Airplanes 737

Service Bulletin

Revision Transmittal Sheet Number: 737-53-1058

Original Issue: April 04, 1980

Revision 4: January 09, 2014

ATA System: 5313

SUBJECT: FUSELAGE - Forward Airstair Stowage Doorway Inspection, Preventive Modification

and Repair

This revision includes all pages of the service bulletin.

COMPLIANCE INFORMATION RELATED TO THIS REVISION

More work is necessary on airplanes changed in accordance with the original issue or Revisions 1, 2 or 3 of this

service bulletin. Airplanes with a repair installed in accordance with the original issue or preventive modification

installed in accordance with the original issue or Revision 1, 2 or 3 of this service bulletin require additional

inspections.

737 airplanes with a forward airstair stowage doorway, Line Numbers 599 and 640 thru 3132 are added to this

service bulletin effectivity.

Federal Aviation Administration (FAA) Airworthiness Directive AD 90-06-02, AD 98-11-04 R1, AD 2008-08-23

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

REASON FOR REVISION

This revision is sent to supply the operator with new inspection instructions and new repair and preventive

modification kits for all airplanes. The new kits provide a different doubler profile to address the fuselage skin

cracking below the lower aft corner of the forward airstair stowage door cutout.

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. Summary - Background section service history is updated.

2. Summary - Planning table is added.

3. Summary - Action section is updated.

4. Summary - Effectivity section, new airplane models are added.

5. Paragraph 1.C., Reason - Service history is updated

6. Paragraph 1.D., Description - New instructions are added and maintenance zone tables are added.

7. Paragraph 1.E., Compliance - New section is added.

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8. Paragraph 1.F., Approval - Alternative method of compliance paragraphs are added.

9. Paragraph 1.G., Manpower - Section is updated

10. Paragraph 1.H., Weight and Balance Changes - Section is updated for new repairs and preventive

modifications. New airplane models are added.

11. Paragraph 1.J., References - Section is updated

12. Paragraph 1.K.2, Damage Tolerance Based Structural Inspections - Section is added.

13. Paragraph 1.M., Software Accomplishment Summary - Section is added.

14. Paragraph 2.A., Material - Price and Availability - New kits are added.

15. Paragraph 2.C.1, Kits/Parts - New kits are added.

16. Paragraph 2.C.2, Parts and Materials Supplied by the Operator - New parts are added.

17. Paragraph 3.A., GENERAL INFORMATION, added new standard notes.

18. Paragraph 3.B., WORK INSTRUCTIONS, added new instructions for all airplanes.

19. FIGURE 1, 2 and FIGURE 3, have been deleted.

20. FIGURE 4 thru FIGURE 14, have been added.

Paragraph 1.A., Effectivity, shows changes of airplane operators. Each operator should examine the Effectivity

paragraph for changes.

Vertical lines are put on the left edge of each page, except in Paragraph 1.A., Effectivity and format changes,

to show the location of all content changes.

Pages with no vertical lines have no important changes.

REVISION HISTORY

Original Issue: April 04, 1980

Revision 1: March 05, 1987

Revision 2: December 07, 1989

Revision 3: March 11, 1993

Revision 4: January 09, 2014

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BOEING SERVICE BULLETIN 737-53-1058
Commercial 

Airplanes 737

Service Bulletin

Summary Number: 737-53-1058

Original Issue: April 04, 1980

Revision 4: January 09, 2014

ATA System: 5313

SUBJECT: FUSELAGE - Forward Airstair Stowage Doorway Inspection, Preventive Modification

and Repair

CONCURRENT REQUIREMENTS

None.

BACKGROUND

Operators have reported cracks in the skin assembly and in the bearstrap at the aft lower corner of the forward

airstair stowage doorway. The cracks, caused by fatigue from cyclic pressurization loading, originated in the

radius of the doorway corner and ranged in length from 0.50 to 2.75 inches. Since the release of Revision 3,

skin cracking was also found outside the existing inspection area at fastener holes in the skin assembly about

5 inches below the radius of the corner. At the time of crack detection the airplanes had accumulated between

16,177 and 74,036 total flight cycles. Continued operation with undetected doorway corner cracks could result

in pressurization difficulties and unscheduled downtime for repairs.

Based on a structural review of the 737 airplane, incorporation of the preventive modification per this service

bulletin is recommended on aging airplanes.

Since the original issue of this bulletin, two operators have reported subsequent crack growth on two airplanes

with the crack repair installed in accordance with the original issue of this service bulletin.

Since the release of Revision 3 there have also been reports of cracking on airplanes that are beyond the

effectivity of the original issue and Revisions 1, 2, or 3 of this service bulletin. Boeing has received 20 reports

of skin cracking at the aft lower corner of the forward airstair stowage doorway which ranged in length from 0.30

to 2.20 inches. The earliest report was on an airplane that had accumulated 22,328 total flight cycles. Boeing

has also received 7 reports of skin cracking at fastener locations about 5 inches below the lower aft corner of

the airstair cutout. The earliest report was on an airplane that had accumulated 42,120 total flight cycles. The

maximum crack length found was 0.125 inches on an airplane that had accumulated 56,123 total flight cycles.

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.

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

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Planning Data Affected Reference

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 (PRR 32882, PRR 35005-249RS)

Get access to the airstair stowage doorway area. At the times specified in Paragraph 1.E., Compliance, do High

Frequency Eddy Current (HFEC), Low Frequency Eddy Current (LFEC) and detailed inspections of the bearstrap

and skin assembly for any crack.

If no crack is found, install the preventive modification in accordance with this service bulletin or do repeat

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

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

service bulletin or contact The Boeing Company for repair instructions and do the repair.

For repairs installed in accordance with original release or preventive modification installed in accordance with

original release, revision 1, 2 or 3, do the inspection at the times specified in Paragraph 1.E., Compliance. If

any crack is found, contact The Boeing Company for repair instructions and do the repair.

On Group 6 airplanes, contact The Boeing Company to get instructions for the inspection, change and/or repair

for this service bulletin, 737-53-1058 Revision 4, and do the instructions.

EFFECTIVITY

737-100/-200/-200C/-300/-400/-500 Airplane(s) with a forward airstair stowage doorway. Refer to Paragraph

1.A.1., Airplanes, for the list of affected airplane(s).

COMPLIANCE

Federal Aviation Administration (FAA) Airworthiness Directive AD 90-06-02, AD 98-11-04 R1, AD 2008-08-23

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

The FAA will possibly release an additional Airworthiness Directive related to this service bulletin. The

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

On Group 6 airplanes, contact The Boeing Company to get instructions for the inspection, change and/or repair

for this service bulletin, 737-53-1058 Revision 4, and do the instructions.

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BOEING SERVICE BULLETIN 737-53-1058
Refer to Paragraph 1.E., Compliance.

INDUSTRY SUPPORT INFORMATION

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

given in this service bulletin.

MANPOWER

Refer to Paragraph 1.G., Manpower.

MATERIAL INFORMATION

Boeing Supplied Kits.

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

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BOEING SERVICE BULLETIN 737-53-1058
Commercial 

Airplanes 737

Service Bulletin

Number: 737-53-1058

Original Issue: April 04, 1980

Revision 4: January 09, 2014

ATA System: 5313

SUBJECT: FUSELAGE - Forward Airstair Stowage Doorway Inspection, Preventive Modification

and Repair

1. PLANNING INFORMATION

A. Effectivity

1. Airplanes

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

Number, and Serial Number data.

This service bulletin is for the airplanes shown below. Refer to PRR 35005-249RS for data about

this change.

GROUP CONFIGURATION DESCRIPTION

Passenger airplanes line numbers 292 thru 598 and 600 thru 639

with a forward airstair stowage doorway. These airplanes have a

bonded skin structure at the lower aft corner of the airstair stowage

doorway.

1 -

Cargo airplanes line numbers 292 thru 639 with a forward airstair

stowage doorway. These airplanes have a bonded skin structure at

the lower aft corner of the airstair stowage doorway.

2 -

Passenger airplanes line numbers 599 and 640 thru 1922 with a

forward airstair stowage doorway. These airplanes have a bonded

skin structure at the lower aft corner of the airstair stowage doorway.

3 -

Cargo airplanes line numbers 640 thru 1113 with a forward airstair

stowage doorway. These airplanes have a bonded skin structure at

the lower aft corner of the airstair stowage doorway.

4 -

Passenger airplanes line numbers 1923 thru 3132 with a forward

airstair stowage doorway. These airplanes have a solid skin structure

at the lower aft corner of the airstair stowage doorway.

5 -

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GROUP CONFIGURATION DESCRIPTION

Airplanes line numbers 1-291 with a forward airstair stowage doorway.

These airplanes have a cold bonded skin.

6 -

Airplane Models:

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

Variable Number Group

PA001 - PA022 6

PA099 6

PA231 - PA232 6

PC001 - PC005 6

PG001 - PG075 6

PG199 6

PG201 - PG230 6

PG251 - PG255 6

PG271 - PG279 6

PG301 - PG314 6

PG331 - PG332 6

PG351 - PG356 6

PG375 6

PG401 - PG403 6

PG431 - PG442 6

PG471 - PG475 6

PG501 - PG505 6

PG571 - PG583 6

PG584 - PG586 1

PG621 - PG630 6

PG651 - PG652 6

PG701 - PG705 6

PH001 1

PH011 - PH013 1

PH021 - PH024 1

PH701 - PH715 6

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BOEING SERVICE BULLETIN 737-53-1058
Variable Number Group

PH731 - PH732 6

PH741 - PH742 6

PH743 1

PJ001 - PJ002 6

PJ003 - PJ009 1

PJ031 - PJ032 6

PJ071 - PJ072 6

PJ101 - PJ104 6

PJ105 - PJ116 1

PJ117 - PJ119 3

PJ201 - PJ219 1

PJ816 - PJ817 5

PK026 - PK029 1

PK047 1

PK051 1

PK061 - PK070 1

PK081 1

PK082 3

PK091 - PK099 1

PK101 - PK103 1

PK111 - PK120 1

PK141 - PK146 1

PK201 - PK203 1

PK204 3

PK211 - PK213 1

PK214 - PK220 3

PK221 - PK223 1

PK231 - PK235 1

PK236 - PK240 3

PK241 1

PK251 - PK258 1

PK271 - PK273 1

PK274 3

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BOEING SERVICE BULLETIN 737-53-1058
Variable Number Group

PK281 - PK282 1

PK283 - PK284 3

PK285 - PK289 1

PK291 1

PK301 - PK306 1

PK307 - PK310 3

PK311 - PK318 1

PK341 1

PK351 - PK358 1

PK359 - PK361 3

PK391 1

PK451 - PK452 1

PK461 - PK469 1

PK495 1

PK501 1

PK502 - PK504 3

PK511 - PK512 1

PK513 - PK515 3

PK519 3

PK521 - PK523 1

PK524 - PK528 3

PK541 - PK551 1

PK552 - PK560 3

PK561 - PK562 1

PK563 - PK565 3

PK581 1

PK591 - PK597 1

PK598 - PK599 3

PK601 - PK610 3

PK611 - PK613 1

PK614 - PK617 3

PK621 - PK622 1

PK623 - PK637 3

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BOEING SERVICE BULLETIN 737-53-1058
Variable Number Group

PK641 - PK642 1

PK661 1

PK662 - PK666 3

PK671 1

PK672 - PK681 3

PK691 - PK693 1

PK694 - PK697 3

PK711 - PK716 1

PK731 3

PK732 - PK734 1

PK735 - PK765 3

PK771 - PK779 3

PK801 - PK804 3

PK819 - PK820 3

PK821 1

PK822 - PK827 3

PK830 3

PK861 1

PK862 - PK863 3

PK871 - PK874 3

PK881 - PK884 3

PK901 - PK910 3

PL001 - PL017 1

PL018 - PL028 3

PL061 3

PL081 3

PL151 3

PL171 - PL172 3

PL201 - PL203 3

PL221 3

PL401 - PL403 1

PL404 - PL417 3

PL421 1

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BOEING SERVICE BULLETIN 737-53-1058
Variable Number Group

PL441 1

PL451 - PL456 3

PL471 3

PL491 3

PL501 - PL506 3

PL551 - PL562 3

PL581 3

PL601 - PL603 3

PL611 3

PL621 - PL626 3

PL631 - PL632 3

PL711 - PL712 6

PL716 6

PL717 - PL735 1

PL756 1

PL761 - PL770 1

PL781 - PL782 1

PL783 - PL788 3

PL793 1

PL801 - PL803 6

PM001 - PM006 3

PM016 - PM017 3

PM021 - PM023 3

PM051 - PM066 3

PM101 - PM119 3

PM141 - PM142 3

PM171 3

PM181 3

PM251 - PM255 3

PM281 - PM283 3

PM381 - PM392 3

PM393 - PM399 5

PM401 - PM417 5

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BOEING SERVICE BULLETIN 737-53-1058
Variable Number Group

PM541 - PM564 5

PN001 - PN002 3

PN021 - PN043 3

PN081 - PN086 3

PN101 - PN117 3

PN131 - PN163 3

PN431 - PN433 3

PN451 - PN456 3

PN471 - PN474 3

PN481 3

PN491 - PN493 3

PN501 - PN502 3

PN511 - PN512 3

PN521 3

PP101 3

PP201 - PP205 3

PP221 3

PP351 - PP353 3

PP376 - PP384 3

PP391 - PP393 3

PP501 - PP510 3

PP511 - PP520 5

PP521 - PP522 3

PP651 - PP652 3

PP801 - PP808 3

PP821 - PP827 3

PP831 - PP848 3

PP851 - PP852 3

PP891 - PP899 3

PP901 - PP924 3

PP925 - PP930 5

PP931 - PP936 3

PP946 - PP948 3

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BOEING SERVICE BULLETIN 737-53-1058
Variable Number Group

PP951 - PP952 3

PP993 3

PQ221 - PQ229 3

PQ230 5

PQ241 - PQ243 3

PQ251 - PQ255 3

PQ256 - PQ267 5

PQ281 - PQ286 3

PQ287 - PQ291 5

PQ298 5

PQ361 - PQ373 5

PQ391 - PQ395 5

PQ401 - PQ418 5

PQ421 5

PQ447 - PQ448 5

PQ472 - PQ475 5

PQ951 5

PQ971 - PQ997 5

PR001 - PR017 5

PR021 - PR030 5

PR081 - PR082 5

PR091 - PR092 5

PR096 5

PR101 5

PR121 - PR122 5

PR131 - PR132 5

PR141 - PR143 5

PR161 - PR172 5

PS601 - PS631 5

PS636 - PS638 5

PS641 - PS642 3

PS651 - PS657 5

PS811 5

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BOEING SERVICE BULLETIN 737-53-1058
Variable Number Group

PS836 - PS837 5

PS841 - PS846 5

PS851 - PS852 5

PS856 5

PS861 - PS863 5

PS866 - PS868 5

PS871 - PS874 5

PS896 - PS897 5

PS956 - PS957 5

PS961 - PS963 5

PS971 - PS978 5

PT041 - PT064 5

PT121 - PT123 3

PT124 - PT138 5

PT146 3

PT147 - PT148 5

PT161 - PT170 5

PT181 - PT182 3

PT183 - PT185 5

PT211 - PT214 3

PT215 - PT220 5

PT295 3

PT501 - PT517 5

PT671 - PT672 5

PT721 - PT725 5

PT871 - PT886 5

PT996 5

PU301 5

PU311 - PU313 5

PV296 5

PV301 - PV302 5

PV356 - PV357 5

PW001 - PW036 3

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BOEING SERVICE BULLETIN 737-53-1058
Variable Number Group

PW037 - PW050 5

PW051 3

PW052 - PW054 5

PW061 3

PW072 5

PW086 - PW088 5

PW091 - PW093 3

PW094 5

PW101 - PW102 5

PW106 5

PW111 - PW117 3

PW118 - PW120 5

PW156 - PW157 5

PW161 - PW162 3

PW163 - PW171 5

PW261 - PW268 5

PW271 - PW276 5

PW278 5

PW281 - PW293 5

PW296 5

PW301 - PW327 5

PW501 - PW503 3

PW504 5

PW556 - PW557 5

PW591 - PW594 3

PW595 - PW596 5

PW661 3

PW662 5

PW701 - PW702 5

PW741 - PW742 5

PW831 5

PW851 - PW856 5

PX071 6

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BOEING SERVICE BULLETIN 737-53-1058
Variable Number Group

PY031 6

PY051 - PY053 2

PY101 - PY103 2

PY161 2

PY221 - PY222 2

PY231 2

PY281 2

PY286 2

PY321 - PY323 6

PY341 - PY346 6

PY361 - PY362 6

PY381 6

PY411 2

PY441 4

PY611 - PY612 2

PY621 2

PY631 4

PY651 4

PY741 4

2. Spares Affected

None

B. Concurrent Requirements

None.

C. Reason

Operators have reported cracks in the skin assembly and in the bearstrap at the aft lower corner of the

forward airstair stowage doorway. The cracks, caused by fatigue from cyclic pressurization loading,

originated in the radius of the doorway corner and ranged in length from 0.50 to 2.75 inches. Since the

release of Revision 3, skin cracking was also found outside the existing inspection area at fastener

holes in the skin assembly about 5 inches below the radius of the corner. At the time of crack detection

the airplanes had accumulated between 16,177 and 74,036 total flight cycles. Continued operation

with undetected doorway corner cracks could result in pressurization difficulties and unscheduled

downtime for repairs.

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BOEING SERVICE BULLETIN 737-53-1058
As a result of the FAA sponsored Aging Fleet Conference, a 737 Structures Working Group with Airline

and Boeing members and FAA observers was formed to review structural service bulletin modifications

and recommend selected bulletins for incorporation of aging airplanes. This service bulletin preventive

modification has been recommended for incorporation on aging 737 airplanes.

Inspection and preventive modification as given in this service bulletin will provide timely crack detection

in the forward airstair stowage doorway and reduce the possibility of future corner cracks.

Since the original issue of this bulletin, two operators have reported subsequent crack growth on two

airplanes with the crack repair installed in accordance with the original issue of this service bulletin.

Since the release of Revision 3 there have also been reports of cracking on airplanes that are beyond

the effectivity of the original issue and Revisions 1, 2, or 3 of this service bulletin. Boeing has received

20 reports of skin cracking at the aft lower corner of the forward airstair stowage doorway which ranged

in length from 0.30 to 2.20 inches. The earliest report was on an airplane that had accumulated 22,328

total flight cycles. Boeing has also received 7 reports of skin cracking at fastener locations about 5

inches below the lower aft corner of the airstair cutout. The earliest report was on an airplane that had

accumulated 42,120 total flight cycles. The maximum crack length found was 0.125 inches on an

airplane that had accumulated 56,123 total flight cycles.

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 was issued to provide improved preventive modification and repair information and to call

for inspection of airplanes repaired per the original issue.

Notice of Status Change dated November 21, 1980 was incorporated in Revision 1.

Revision 2 of this bulletin was issued to provide the recommendations of the Aging Fleet 737 Structures

Working Group.

Revision 3 was sent to supply the operator with supplemental kits and new kit information. The new

kits and supplemental kits supplied larger parts with material for additional edge margin. The

supplemental fastener kit was added to supply oversize fasteners when the new repair replaces the

original issue repair. Also, the repeat inspection interval was changed from "C" check to 4,500 flight

cycles. This revision also clarified the procedure of the inspection and crack termination in FIGURE 1.

Revision 4 is sent to supply the operator with new inspection instructions and new repair and preventive

modification kits for all airplanes. The new kits provide a different doubler profile to address the fuselage

skin cracking below the lower aft corner of the forward airstair stowage door cutout.

D. Description

Get access to the airstair stowage doorway area. At the times specified in Paragraph 1.E., Compliance,

do High Frequency Eddy Current (HFEC), Low Frequency Eddy Current (LFEC) and detailed inspections

of the bearstrap and skin assembly for any crack.

If no crack is found, install the preventive modification in accordance with this service bulletin or do

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

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BOEING SERVICE BULLETIN 737-53-1058
If any crack is found in the skin assembly or bearstrap, install the permanent repair in accordance with

this service bulletin or contact The Boeing Company for repair instructions and do the repair.

For repairs installed in accordance with original release or preventive modification installed in accordance

with original release, revision 1, 2 or 3, do the inspection at the times specified in Paragraph 1.E.,

Compliance. If any crack is found, contact The Boeing Company for repair instructions and do the

repair.

On Group 6 airplanes, contact The Boeing Company to get instructions for the inspection, change

and/or repair for this service bulletin, 737-53-1058 Revision 4, and do the instructions.

Revision 4 - More work is necessary on airplanes changed in accordance with the original issue or

Revisions 1, 2 or 3 of this service bulletin. Airplanes with a repair installed in accordance with the

original issue or preventive modification installed in accordance with the original issue or Revision 1,

2 or 3 of this service bulletin require additional inspections.

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

Group 1, 3:

Affected Maintenance Zones

Model Zone

737-200 2-6

Group 2, 4:

Affected Maintenance Zones

Model Zone

737-200C 2-6

Group 3, 5:

Affected Maintenance Zones

Model Zone

737-300, 737-400, 737-500 206

Group 6:

Affected Maintenance Zones

Model Zone

737-100, 737-200, 737-200C 2-6

E. Compliance

Federal Aviation Administration (FAA) Airworthiness Directive AD 90-06-02, AD 98-11-04 R1, AD

2008-08-23 and AD 2008-09-13 are related to this service bulletin.

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BOEING SERVICE BULLETIN 737-53-1058
The FAA will possibly release an additional Airworthiness Directive related to this service bulletin. The

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

As recommended by the model 737 Aging Fleet Structures Task Group, accomplish the preventive

modification per the accomplishment instructions at or before the accumulation of 75,000 flight cycles.

The repair/preventive modifications of this service bulletin have been reviewed as required by AD

98-11-04 R1 paragraphs (e) or (g), AD 2008-08-23 paragraphs (g) and (h) and AD 2008-09-13

paragraphs (g) and (h). The repair/preventive modifications, per Revision 4, are found to affect SSI

F-14A and makes the F-14A inspections ineffective in the repair/preventive modification area. The

alternate inspection intervals for the repair/preventive modification are shown in Table 3: Post Repair

and Post Preventive Modification Inspections. The repair/preventive modification also affects SSI F-14B

and prohibits the external LFEC inspection of F-14B. However the internal inspection options of F-14B

provides the required Damage Tolerance Rating (DTR) in this area. Therefore, an alternate inspection

for F-14B is not necessary in the area of the repair/preventive modification.

Boeing repairs that were previously approved by Boeing Authorized Representative (AR) via FAA

8100-9 Form terminates the inspections of this service bulletin. For post repair inspection, refer to the

approval documents.

Group 1-2:

Table 1: Skin Assembly and Bearstrap Inspections

Repeat Interval (Not to

Exceed)

Compliance Time (whichever occurs later)Condition Action

4,500 flight

cycles

Within 4,500 flight

cycles after the Revision 4 date of this

service bulletin.

Before 20,000

total flight cycles

Do a HFEC inspection and detailed inspection for any crack

in the bearstrap in accordance

with Paragraph 3.B., Work Instructions, PART 2, step 1.

Airplanes without a Preventive Modification or

Repair installed in accordance with the original issue or Revision 1, 2 or 3

of this service bulletin. (a) (b)

4,500 flight

cycles

Within 4,500 flight

cycles after the Revision 4 date of this

service bulletin.

Before 20,000

total flight cycles

Do a HFEC inspection and detailed inspection for any crack

in the skin assembly in accordance with Paragraph 3.B.,

Work Instructions, PART 2, step

1.

(a) (b)

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BOEING SERVICE BULLETIN 737-53-1058
Group 1-2:

Table 1: Skin Assembly and Bearstrap Inspections

Repeat Interval (Not to

Exceed)

Compliance Time (whichever occurs later)Condition Action

4,500 flight

cycles

Within 4,500 flight

cycles after the Revision 4 date of this

service bulletin.

Before 20,000

total flight cycles

Do a HFEC inspection and detailed inspection for any crack

in the bearstrap in accordance

with Paragraph 3.B., Work Instructions, PART 2, step 1.

Airplanes with a Repair

installed in accordance

with the original issue of

this service bulletin.

(a) (b)

4,500 flight

cycles

Within 4,500 flight

cycles after the Revision 4 date of this

service bulletin.

Before 20,000

total flight cycles

Do a detailed inspection for any

crack in the skin assembly in

accordance with Paragraph

3.B., Work Instructions, PART

2, step 1.

(a) (b)

4,500 flight

cycles

Within 4,500 flight

cycles after the Revision 4 date of this

service bulletin.

Before 20,000

total flight cycles

Do a LFEC inspection for any

crack in the skin assembly and

bearstrap in accordance with

Paragraph 3.B., Work Instructions, PART 2, step 1.

(a) (b)

6,000 flight

cycles

Within 4,500 flight

cycles after the Revision 4 date of this

service bulletin.

Before 30,000

total flight cycles

Do a HFEC Inspection and Detailed Inspection for any crack

in the Bearstrap in accordance

with Paragraph 3.B., Work Instructions, PART 2, step 1.

Airplanes with a Preventive Modification installed

in accordance with the

original issue, Revision 1,

2 or 3 of this service bulletin. (a) (b)

6,000 flight

cycles

Within 4,500 flight

cycles after the Revision 4 date of this

service bulletin.

Before 30,000

total flight cycles

Do a LFEC Inspection for any

crack in the skin assembly and

Bearstrap in accordance with

Paragraph 3.B., Work Instructions, PART 2, step 1.

(a) (b)

6,000 flight

cycles

Within 4,500 flight

cycles after the Revision 4 date of this

service bulletin.

Before 30,000

total flight cycles

Do a Detailed Inspection for any

crack in the skin assembly in

accordance with Paragraph

3.B., Work Instructions, PART

2, step 1.

(a) (b)

Install a repair in accordance Before further flight -

with Paragraph 3.B., Work Instructions, PART 2, step 1.e.

If any crack is found in the

skin assembly or

bearstrap, but not both.

(b)

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BOEING SERVICE BULLETIN 737-53-1058
Group 1-2:

Table 1: Skin Assembly and Bearstrap Inspections

Repeat Interval (Not to

Exceed)

Compliance Time (whichever occurs later)Condition Action

Install a repair in accordance Before further flight -

with Paragraph 3.B., Work Instructions, PART 2, step 1.f.

If any crack is found in

both the skin assembly

and bearstrap.

(b)

(a) Installation of the Preventive Modification in accordance with Paragraph 3.B., Work Instructions, PART

2, step 1.a. or PART 2, step 1.b or PART 2, step 1.c. terminates this inspection. Post preventive modification

inspections are provided in Table 3.

(b) Installation of the Repair in accordance with Paragraph 3.B., Work Instructions, PART 2, step 1.e. or PART

2 step 1.f. terminates this inspection. Repairs that were previously accomplished in accordance with Revision 1, 2 or 3 of this service bulletin terminate this inspection. Post repair inspections are provided in

Table 3.

Group 3-5:

Table 2: Skin Assembly and Bearstrap Inspections

Repeat Interval (Not to

Exceed)

Compliance Time (whichever occurs later)Condition Action

6,000 flight

cycles

Within 4,500 flight

cycles after the Revision 4 date of this

service bulletin.

Before 20,000

total flight cycles

Do a HFEC and Detailed Inspection for any crack in the

Bearstrap in accordance with

Paragraph 3.B., Work Instructions, PART 2, step 1.

All Airplanes.

(a) (b)

6,000 flight

cycles

Within 4,500 flight

cycles after the Revision 4 date of this

service bulletin.

Before 20,000

total flight cycles

Do a LFEC Inspection for any

crack in the skin assembly and

Bearstrap in accordance with

Paragraph 3.B., Work Instructions, PART 2, step 1.

(a) (b)

6,000 flight

cycles

Within 4,500 flight

cycles after the Revision 4 date of this

service bulletin.

Before 20,000

total flight cycles

Do a Detailed Inspection for any

crack in the skin assembly in

accordance with Paragraph

3.B., Work Instructions, PART

2, step 1.

(a) (b)

Install a repair in accordance Before further flight -

with Paragraph 3.B., Work Instructions, PART 2, step 1.e.

If any crack is found in the

skin assembly or

bearstrap, but not both.

(b)

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BOEING SERVICE BULLETIN 737-53-1058
Group 3-5:

Table 2: Skin Assembly and Bearstrap Inspections

Repeat Interval (Not to

Exceed)

Compliance Time (whichever occurs later)Condition Action

Install a repair in accordance Before further flight -

with Paragraph 3.B., Work Instructions, PART 2, step 1.f.

If any crack is found in

both the skin assembly

and bearstrap.

(b)

(a) Installation of the Preventive Modification in accordance with Paragraph 3.B., Work Instructions, PART

2, step 1.d. terminates this inspection. Post preventive modification inspections are provided in Table 4.

(b) Installation of the Repair in accordance with Paragraph 3.B., Work Instructions, PART 2, step 1.e. or PART

2, step 1.f. terminates this inspection. Post repair inspections are provided in Table 4.

Group 1-2:

Table 3: Post Repair and Post Preventive Modification Inspections

Repeat

Interval

(Not to

Exceed)

Compliance Time (whichever occurs later)Condition Action

24,000

flight cycles

Within 4,500

flight cycles

after the Revision 4 date of

this service

bulletin.

Within 12,000

flight cycles

after the installation of

the repair or

preventive

modification.

Before

60,000 total

flight cycles.

Do an Internal HFEC Inspection for any crack in the

Bearstrap and Skin Assembly and an Internal General

Visual Inspection for any

crack in the frame outer

chord in accordance with

Paragraph 3.B., Work Instructions PART 3, step 1.(Option

A)

Airplanes that have

a Repair installed in

accordance with the

Revision 1, 2, or 3

of this service bulletin.

OR

4,000

flight cycles

Within 4,500

flight cycles

after the Revision 4 date of

this service

bulletin.

Within 12,000

flight cycles

after the installation of

the repair or

preventive

modification.

Before

60,000 total

flight cycles.

Do an External LFEC Inspection for any crack in the

Bearstrap and Skin Assembly in accordance with Paragraph 3.B., Work Instructions

PART 3, step 1. (Option B)

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BOEING SERVICE BULLETIN 737-53-1058
Group 1-2:

Table 3: Post Repair and Post Preventive Modification Inspections

Repeat

Interval

(Not to

Exceed)

Compliance Time (whichever occurs later)Condition Action

24,000

flight cycles

Within 12,000

flight cycles

after the installation of

the repair or

preventive

modification.

Before

60,000 total

flight cycles.

Do an Internal HFEC Inspection for any crack in the

Bearstrap and Skin Assembly and an Internal General

Visual Inspection for any

crack in the frame outer

chord in accordance with

Paragraph 3.B., Work Instructions, PART 3, step 2. (Option A)

Airplanes that have

a Repair or Preventive Modification installed in accordance with Revision

4 of this Service

Bulletin.

OR

4,000

flight cycles

Within 12,000 .

flight cycles

after the installation of

the repair or

preventive

modification.

Before

60,000 total

flight cycles.

Do an External LFEC Inspection for any crack in the

Bearstrap and Skin Assembly in accordance with Paragraph 3.B., Work Instructions, PART 3, step 2. (Option B)

Contact The Boeing Compa- Before further flight -

ny for repair instructions and

do the repair.

If any crack is

found.

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BOEING SERVICE BULLETIN 737-53-1058
Group 3-5:

Table 4: Post Repair and Post Preventive Modification Inspections

Repeat

Interval

(Not to

Exceed)

Compliance Time (whichever occurs later)Condition Action

24,000

flight cycles

Within 12,000 flight cycles

after the installation of the

repair or preventive modification.

Before

60,000 total

flight cycles.

Do an Internal HFEC Inspection for any crack in the

Bearstrap and Skin Assembly and an Internal General

Visual Inspection for any

crack in the frame outer

chord in accordance with

Paragraph 3.B., Work Instructions, PART 3, step 2. (Option A)

Airplanes that have

a Repair or Preventive Modification installed in accordance with Revision

4 of this Service

Bulletin.

OR

4,000

flight cycles

Within 12,000 flight cycles

after the installation of the

repair or preventive modification.

Before

60,000 total

flight cycles.

Do an External LFEC Inspection for any crack in the

Bearstrap and Skin Assembly in accordance with Paragraph 3.B., Work Instructions, PART 3, step 2. (Option B)

Contact The Boeing Compa- Before further flight -

ny for repair instructions and

do the repair.

If any crack is

found.

Group 6:

On Group 6 airplanes, contact The Boeing Company to get instructions for the inspection, change

and/or repair for this service bulletin, 737-53-1058 Revision 4, and do the instructions within 120 days

of the issue date of revision 4 to 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.

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BOEING SERVICE BULLETIN 737-53-1058
The Manager of the FAA Seattle Aircraft Certification Office (ACO) approves the action (i.e. repair or

preventive modification) defined in this service bulletin, 737-53-1058 Revision 4 as an alternative

method of compliance to the modifications per SB 737-53-1058 Revision 1, of the Aging Airplane

Service Bulletin Structural Modification Program - Model 737-100/-200/-200C of paragraph (A) of AD

90-06-02. This alternative method of compliance applies only to the modification specified in Boeing

document D6-38505 for service bulletin 737-53-1058. All provisions of AD 90-06-02 that are not

specifically referenced in the above statement remain fully applicable and must be complied with.

For Boeing Model 737-100/200 series airplanes, the Manager of the FAA Seattle ACO approves the

supplemental inspection methods, thresholds and repeat intervals as given in Tables 3 and 4 of

Paragraph 1.E, Compliance for the repair or preventive modification defined in the applicable tables

of Paragraph 1.E., Compliance, of Boeing Alert Service Bulletin 737-53-1058, Revision 4 as a method

of compliance (MOC) to Paragraph (g) of AD 98-11-04 R1 for the inspections of Structurally Significant

Item (SSI) F-14A. This approval applies to this SSI and only for the portions of the bear strap and skin

that have been repaired in accordance with this service bulletin. 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.

In addition, for Boeing Model 737-200C series airplanes, the Manager of the FAA Seattle ACO approves

the inspection methods, thresholds, repeat intervals, as given in Table 3 and 4 of Paragraph 1.E for

the repairs and preventive modification defined in the applicable tables of Paragraph 1.E., Compliance

, of Boeing Alert Service Bulletin 737-53A1058, Revision 4 as an AMOC to the inspections of SSI F-14A

required by paragraphs (g) and (h) of AD 2008-08-23. This approval applies to this SSI and only for

the portions of the bearstrap and skin that have been repaired in accordance with this service bulletin.

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.

In addition, for Boeing Model 737-300/-400/-500 series airplanes, the Manager of the FAA Seattle ACO

approves the inspection methods, thresholds, repeat intervals as given in Table 4 for the repairs or

preventive modification defined in the applicable tables of Paragraph 1.E., Compliance, of Boeing Alert

Service Bulletin 737-53A1058, Revision 4 as an AMOC to the inspections of SSI F-14A as required by

paragraphs (g) and (h) of AD 2008-09-13. This approval applies to this SSI and only for the portions

of the bearstrap and frame chord that have been repaired in accordance with this service bulletin. 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 examine the work

— Time to cure the materials

— Time to make the parts

— Time to find the tools.

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BOEING SERVICE BULLETIN 737-53-1058
Group 1-2:

Table 1: No preventive modification or repair installed at the original issue of this service bulletin

Task Number of Persons Task Hours Elapsed Hours

Open Access 2 0.50 0.25

FIGURE 5 1 1.75 1.75

FIGURE 6 1 1.75 1.75

Close Access 2 0.50 0.25

TOTAL FOR EACH AIRPLANE 4.50 4.00

Note: If a repair is required more time will be needed but cannot be specified as the extent of the repair is unknown and can be different on each airplane.

Group 1-2:

Table 2: Preventive modification installed at the original issue of this service bulletin

Task Number of Persons Task Hours Elapsed Hours

Open Access 2 0.50 0.25

FIGURE 5 1 1.75 1.75

FIGURE 7 1 1.75 1.75

Close Access 2 0.50 0.25

TOTAL FOR EACH AIRPLANE 4.50 4.00

Note: If a repair is required more time will be needed but cannot be specified as the extent of the repair is unknown and can be different on each airplane.

Group 1:

Table 3: Preventive modification installed at Revision 1, 2 or 3 of this service bulletin

Task Number of Persons Task Hours Elapsed Hours

Open Access 2 0.50 0.25

FIGURE 5 1 1.75 1.75

FIGURE 8 1 2.00 2.00

Close Access 2 0.50 0.25

TOTAL FOR EACH AIRPLANE 4.75 4.25

Note: If a repair is required more time will be needed but cannot be specified as the extent of the repair is unknown and can be different on each airplane.

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BOEING SERVICE BULLETIN 737-53-1058
Group 2:

Table 4: Preventive modification installed at Revision 1, 2 or 3 of this service bulletin

Task Number of Persons Task Hours Elapsed Hours

Open Access 2 0.50 0.25

FIGURE 5 1 1.75 1.75

FIGURE 8 1 2.00 2.00

Close Access 2 0.50 0.25

TOTAL FOR EACH AIRPLANE 4.75 4.25

Note: If a repair is required more time will be needed but cannot be specified as the extent of the repair is unknown and can be different on each airplane.

Group 1:

Table 5: Repair installed at the original issue of this service bulletin

Task Number of Persons Task Hours Elapsed Hours

Open Access 2 0.50 0.25

FIGURE 5 1 1.75 1.75

FIGURE 10 1 1.50 1.50

Close Access 2 0.50 0.25

TOTAL FOR EACH AIRPLANE 4.25 3.75

Note: If a repair is required more time will be needed but cannot be specified as the extent of the repair is unknown and can be different on each airplane.

Group 2:

Table 6: Repair installed at the original issue of this service bulletin

Task Number of Persons Task Hours Elapsed Hours

Open Access 2 0.50 0.25

FIGURE 5 1 1.75 1.75

FIGURE 11 1 1.50 1.50

Close Access 2 0.50 0.25

TOTAL FOR EACH AIRPLANE 4.25 3.75

Note: If a repair is required more time will be needed but cannot be specified as the extent of the repair is unknown and can be different on each airplane.

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BOEING SERVICE BULLETIN 737-53-1058
Group 3-5:

Table 7: Inspection

Task Number of Persons Task Hours Elapsed Hours

Open Access 2 0.50 0.25

FIGURE 5 1 1.75 1.75

FIGURE 9 1 2.00 2.00

Close Access 2 0.50 0.25

TOTAL FOR EACH AIRPLANE 4.75 4.25

Note: If a repair is required more time will be needed but cannot be specified as the extent of the repair is unknown and can be different on each airplane.

Group 1-5:

Table 8: Open Hole Inspection Before Repair and Preventive Modification Installation

Task Number of Persons Task Hours Elapsed Hours

Inspection 1 1.6 1.6

Group 1-5:

Table 9: Post Repair and Post Preventive Modification Inspections

Task Number of Persons Task Hours Elapsed Hours

Open Access 2 0.50 0.25

FIGURE 13 (Option A) 1 1.50 1.50

FIGURE 14 (Option B) 1 1.00 1.00

Close Access 1 0.50 0.25

TOTAL FOR EACH AIRPLANE (Option A) 2.50 2.00

TOTAL FOR EACH AIRPLANE (Option B) 2.00 1.5

H. Weight and Balance Changes

Group 1-5:

Modification - Skin Assembly or Bearstrap (Kits 65C20843-35, 65C20843-36, 65C20843-39) without

previous preventive modification or repair installed

Change in Moment

(Pounds-Inches)

Change in Weight

(Pounds)

Applicability

737-100 +9.0 +3,010

737-200/-200C +9.0 +2,690

737-300 +9.0 +2,300

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BOEING SERVICE BULLETIN 737-53-1058
Group 1-5:

Modification - Skin Assembly or Bearstrap (Kits 65C20843-35, 65C20843-36, 65C20843-39) without

previous preventive modification or repair installed

Change in Moment

(Pounds-Inches)

Change in Weight

(Pounds)

Applicability

737-400 +9.0 +1,650

737-500 +9.0 +2,780

Group 1-5:

Modification - Skin Assembly and Bearstrap (Kits 65C20843-37, 65C20843-38, 65C20843-40) without

previous preventive modification or repair installed

Change in Moment

(Pounds-Inches)

Change in Weight

(Pounds)

Applicability

737-100 +11.0 +3,690

737-200/-200C +11.0 +3,290

737-300 +11.0 +2,800

737-400 +11.0 +2,010

737-500 +11.0 +3,400

Group 1-5:

With Aluminum Doubler and One Steel Tripler Replacing Previously Installed Preventive Modification

or Repair

Change in Moment

(Pounds-Inches)

Change in Weight

(Pounds)

Applicability

737-100 +3.0 +1,010.0

737-200/-200C +3.0 +900.0

737-300 +3.0 +770.0

737-400 +3.0 +550.0

737-500 +3.0 + 920.0

Group 1-5:

With Aluminum Doubler and Two Steel Tripler Replacing Previously Installed Preventive Modification

or Repair

Change in Moment

(Pounds-Inches)

Change in Weight

(Pounds)

Applicability

737-100 +5.0 +1,680.0

737-200/-200C +5.0 +1,500.0

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BOEING SERVICE BULLETIN 737-53-1058
Group 1-5:

With Aluminum Doubler and Two Steel Tripler Replacing Previously Installed Preventive Modification

or Repair

Change in Moment

(Pounds-Inches)

Change in Weight

(Pounds)

Applicability

737-300 +5.0 +1,280.0

737-400 +5.0 +920.0

737-500 +5.0 + 1,540.0

Group 6:

None.

I. Electrical Load Data

Not changed

J. References

1. Existing Data:

a. Engineering Change Memo PRR 35005-249RS

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

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

d. 737-100/200 Aircraft Maintenance Manual (AMM) 52-61-0

e. 737-300/400/500 Aircraft Maintenance Manual (AMM) 52-61-50

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

90-06-02, 98-11-04 R1

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

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

i. Boeing Document D6-37089: “737 Supplemental Structural Inspection Document (SSID)

Revision E".

j. Boeing Document D6-38505: “Aging Airplane Service Bulletin Structural Modification Program

- Model 737-100/-200/-200C.

k. 737-100/200 Structural Repair Manual (SRM) 51-30-02

l. 737-300 Structural Repair Manual (SRM) 51-40-02

m. 737-400 Structural Repair Manual (SRM) 51-40-02

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BOEING SERVICE BULLETIN 737-53-1058
n. 737-500 Structural Repair Manual (SRM) 51-40-02

2. Data Supplied with this Service Bulletin:

a. Drawings:

Drawing No Title Sheet DCN/REV ADCN

Fwd Airstairs Reinforcement STA.302.6 - 1 A 1

352.6

65C20843

2 B 4

3 - -

PL C 11

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

Drawing Number Title

65-45800 Skin and Stringer Installation - Section 41

65C34778 Skin and Stringer Installation - Forward Entry and Galley Doors

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. 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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BOEING SERVICE BULLETIN 737-53-1058
2. MATERIAL INFORMATION

A. Material - Price and Availability

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.

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

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

2. Fax to (206) 662-7145

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 4 date of

this Service Bulletin

(US Dollars)

ROLT as of the Revision 4 date of this

Service Bulletin (Calendar Days)

Kit Number Name Date QTY

65-91127-1 Modification Kit - - Inactive For Procurement

65-91127-2 Repair Kit - - Inactive For Procurement

65-91127-3 Repair Kit - - Inactive For Procurement

65C20843-13 Kit - - Inactive For Procurement

65C20843-14 Kit - - Inactive For Procurement

65C20843-15 Kit - - Inactive For Procurement

65C20843-16 Kit - - Inactive For Procurement

65C20843-17 Kit - - Inactive For Procurement

65C20843-18 Kit - - Inactive For Procurement

65C20843-23 Supplemental Kit - - Inactive For Procurement

65C20843-24 Supplemental Kit - - Inactive For Procurement

65C20843-25 Supplemental Kit - - Inactive For Procurement

65C20843-26 Supplemental Kit - - Inactive For Procurement

65C20843-27 Supplemental Kit - - Inactive For Procurement

65C20843-28 Supplemental Kit - - Inactive For Procurement

65C20843-29 Kit - - Inactive For Procurement

65C20843-30 Kit - - Inactive For Procurement

65C20843-31 Kit - - Inactive For Procurement

65C20843-32 Kit - - Inactive For Procurement

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BOEING SERVICE BULLETIN 737-53-1058
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 4 date of

this Service Bulletin

(US Dollars)

ROLT as of the Revision 4 date of this

Service Bulletin (Calendar Days)

Kit Number Name Date QTY

65C20843-33 Kit - - Inactive For Procurement

65C20843-34 Kit - - Inactive For Procurement

65C36884-1 Fastener Kit - - Inactive For Procurement

65C20843-35 Top Kit 13-May-2013 30 555 $2,024.00

65C20843-36 Top Kit - - 555 $1,841.00

65C20843-37 Top Kit 13-May-2013 70 555 $1,863.00

65C20843-38 Top Kit - - 555 $2,142.00

65C20843-39 Top Kit 13-May-2013 30 555 $1,756.00

65C20843-40 Top Kit 13-May-2013 70 555 $1,779.00

B. Industry Support Information

Boeing warranty remedies are not available for the inspection, repair and modification procedures given

in this service bulletin.

C. Parts Necessary for Each Airplane

1. Kits/Parts:

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

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.

Applicability Usage Kit Number

Repair Crack in Skin, 65C20843-35

Bonded Doubler or

Bearstrap

Groups 1 and 3

Repair Crack in Skin, 65C20843-37

Bonded Doubler and

Bearstrap

Repair Crack in Skin, 65C20843-36

Bonded Doubler or

Bearstrap

Groups 2 and 4

Repair Crack in Skin, 65C20843-38

Bonded Doubler and

Bearstrap

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BOEING SERVICE BULLETIN 737-53-1058
Applicability Usage Kit Number

Repair Crack in Skin, 65C20843-39

Bonded Doubler or

Bearstrap

Group 5

Repair Crack in Skin, 65C20843-40

Bonded Doubler and

Bearstrap

NOTE: The table below lists the inactive kits and what the superseding replacement kit is.

Inactive Supplemen- Superseding Kit

tal Kit

Inactive Kit

65C20843-13, 29 65C20843-24 65C20843-35

65C20843-14, 30 65C20843-25 65C20843-36

65C20843-15, 31 65C20843-26 65C20843-37

65C20843-16, 32 65C20843-27 65C20843-38

65C20843-17, 33 65C20843-23 65C20843-39

65C20843-18, 34 65C20843-28 65C20843-40

Kit 65C20843 - AIRSTAIRS REINFORCEMENT STA 302.6 - STA 352.6

Existing Part Notes

Number

New Part Number QTY Name

-40 -39 -38 -37 -36 -35

TOP KIT - 65C20843-29

AIRSTAIR REINFORCEMENT

65C20843-35 . . . . . -

TOP KIT - 65C20843-30

AIRSTAIR REINFORCEMENT

65C20843-36 . . . . - .

TOP KIT - 65C20843-31

AIRSTAIR REINFORCEMENT

65C20843-37 . . . - . .

TOP KIT - 65C20843-32

AIRSTAIR REINFORCEMENT

65C20843-38 . . - . . .

TOP KIT - 65C20843-33

AIRSTAIR REINFORCEMENT

65C20843-39 . - . . . .

TOP KIT - 65C20843-34

AIRSTAIR REINFORCEMENT

65C20843-40 - . . . . .

EXTERNAL (a) (b) (c)

TRIPLER

65C20843-21 1 1 1 1 1 1

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BOEING SERVICE BULLETIN 737-53-1058
Kit 65C20843 - AIRSTAIRS REINFORCEMENT STA 302.6 - STA 352.6

Existing Part Notes

Number

New Part Number QTY Name

-40 -39 -38 -37 -36 -35

EXTERNAL (a) (b) (c)

TRIPLER

65C20843-22 1 . 1 1 . .

KIT DETAIL - EX- (a) (b) (c)

TERNAL DOUBLER

65C20843-41 1 1 1 1 1 1

BACB30KF6A10 4 2 4 4 2 2 BOLT (d)

BOLT, 100 DEG (d)

HEX D

BACB30KF6A11 7 . 4 7 3 .

BACB30KF6A12 . . 1 . . . BOLT (d)

BACB30KF6A3 44 44 34 44 34 44 BOLT (d)

BACB30KF6A4 9 9 8 9 8 9 BOLT (d)

BOLT, 100 DEG (d)

HEX D

BACB30KF6A5 23 23 27 23 27 23

BACB30KF6A6 128 128 28 128 36 128 BOLT (d)

BACB30KF6A7 13 42 108 13 106 42 BOLT, HEX DRIVE (d)

BACB30KF6A8 42 14 18 42 47 14 BOLT (d)

BOLT, 100 DEG (d)

HEX D

BACB30KF6A9 1 4 36 1 7 4

BACB30KF8A7 5 5 . 5 . 5 BOLT (d)

BACB30KF8A8 2 2 . 2 . 2 BOLT (d)

BACB30KF8A9 1 1 . 1 . 1 BOLT (d)

BACC30R6 278 272 273 278 273 272 COLLAR

BACC30R8 8 8 . 8 . 8 COLLAR

BACR15GF5D7 33 33 . 33 . 33 RIVET, 100 DEG (d)

BACR15GF5D8 . . 33 . 33 . RIVET, 100 DEG (d)

BACR15GF6D10 1 6 12 1 . 6 RIVET, 100 DEG (d)

BACR15GF6D11 5 . . 5 . . RIVET, 100 DEG (d)

BACR15GF6D7 1 1 1 1 1 1 RIVET, 100 DEG (d)

BACR15GF6D8 10 10 . 10 12 10 RIVET, 100 DEG (d)

BACR15GF6D9 11 11 3 11 15 11 RIVET, 100 DEG (d)

(a) Discard the existing part.

(b) This part is not used in production.

(c) You cannot use the existing part to replace the new or changed part

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BOEING SERVICE BULLETIN 737-53-1058
Kit 65C20843 - AIRSTAIRS REINFORCEMENT STA 302.6 - STA 352.6

Existing Part Notes

Number

New Part Number QTY Name

-40 -39 -38 -37 -36 -35

(d) 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.

2. Parts and Materials Supplied by the Operator:

Part Number / Specifica- QTY Name Notes

tion

Chemical Conversion (a)

Coating

Type 2, Class A 1 Ounce

BMS 10-11, Type I 2 Ounce Primer (b)

BMS 5-95, Type I or II, Class 8 Ounce Sealant (b)

B-1/2 or 2

2024-T3 1 Filler (Skin Assembly) Maximum size 10 x 4 inches. (c)

2024-T3 1 Filler (Bearstrap) Maximum size 10 x 4 inches. (d)

(a) Refer to SOPM 20-43-03 for material sources.

(b) See the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier

data

(c) Fabricate from 0.072 inch thick material. Refer to FIGURE 12.

(d) Fabricate from 0.100 inch thick material. Refer to FIGURE 12.

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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BOEING SERVICE BULLETIN 737-53-1058

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. 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.

6. A Detailed Inspection is defined as: An intensive examination of a specific item,

installation, or assembly to detect damage, failure, or irregularity. Available lighting

is normally supplemented with a direct source of good lighting at an intensity deemed

appropriate. Inspection aids such as mirrors, magnifying lenses, etc. may be

necessary. Surface cleaning and elaborate procedures may be required.

7. A General Visual Inspection is defined as: A visual examination of an interior or

exterior area, installation or assembly to detect obvious damage, failure or irregularity.

This level of inspection is made from within touching distance unless otherwise

specified. A mirror may be necessary to enhance visual access to all exposed surfaces

in the inspection area. This level of inspection is made under normally available

lighting conditions such as daylight, hangar lighting, flashlight or drop-light and may

require removal or opening of access panels or doors. Stands, ladders or platforms

may be required to gain proximity to the area being checked.

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BOEING SERVICE BULLETIN 737-53-1058
8. These work instructions refer to procedures included in other Boeing documents.

When the words "refer to" are used and the operator has an accepted alternative

procedure, the accepted alternative procedure can be used. When the words "in

accordance with" are included in the instruction, the procedure in the Boeing document

must be used.

9. Boeing Service Letter 737-SL-51-042, Damage Reporting and Repair Plan/Design

Guidelines, is an acceptable procedure to request information from Boeing for

additional structural repair instructions. The Service Letter describes what information

must be provided to Boeing before a structural repair can be provided.

10. Refer to Appendix A for the Flight Safety Section.

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. Group 1-5: General repair notes in addition to 65C20843 parts list notes:

– Maintain a minimum 2D edge margin on all repair/preventive modification parts

except for repair filler. Maintain a 1.5D edge margin on fillers.

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

all hi-lok fasteners wet with BMS 5-95 sealant in transition fit or close reamed

holes as defined within 65C20843 parts list.

– Before clamp up, shim all gaps greater than 0.01 inches up to a maximum of

0.04 inches. Contact The Boeing Company for additional instructions and do

the instructions 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 accepted procedure.

– When installing repair or modification parts in accordance with Revision 4 of this

Service Bulletin, it is structurally acceptable to install a 1/64 oversize fastener

(BACB30LW6A) at existing BACB30KF6A locations such that either transition

or close ream fastener installation is maintained. Hole size for a close ream fit

is, 0.2339 - 0.2349 inch diameter hole,and hole size for a transition fit is, 0.232

- 0.235 inch diameter hole.

14. Group 1-2: Fastener hole oversize notes in addition to 65C20843 parts list notes for

airplanes that have an existing repair or preventive modification installed:

– It is structurally acceptable to install a 1/64 oversize fastener (BACB30LW6A)

at existing BACB30KF6A locations such that either transition or close ream

fastener installation is maintained. Use a close ream hole when the hole is

through both stainless steel and aluminum parts. Use a transition fit hole when

the hole is through aluminum parts only. Close ream hole diameter is 0.2339 -

0.2349 and transition fit hole diameter is 0.232 - 0.235.

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BOEING SERVICE BULLETIN 737-53-1058
– It is structurally acceptable to install a 1/64 oversize fastener (BACB30LW8A)

at existing BACB30KF8A locations such that either transition or close ream

fastener installation is maintained. Use a close ream hole when the hole is

through both stainless steel and aluminum parts. Use a transition fit hole when

the hole is through aluminum parts only. Close ream hole diameter is 0.2963 -

0.2973 and transition fit hole diameter is 0.294 - 0.297.

– It is structurally acceptable to install a BACR15GF6D rivet at existing

BACR15GF5D locations.

– It is structurally acceptable to install a BACR15GF7D rivet at existing

BACR15GF6D locations.

B. WORK INSTRUCTIONS

Group 6:

On Group 6 airplanes, contact The Boeing Company to get instructions for the inspection, change

and/or repair for this service bulletin, 737-53-1058 Revision 4, and do the instructions.

Group 1-5:

PART 1 - GET ACCESS

1. For airplanes with a forward airstair installed, extend the forward airstair. For airplanes without a

forward airstair installed, open the forward airstair door. Refer to 737-100/200 AMM 52-61-0 and

737-300/400/500 AMM 52-61-50 as an accepted procedure to open the forward airstair door.

Group 1-5:

PART 2 - SKIN ASSEMBLY AND BEARSTRAP INSPECTIONS

1. Determine what preventive modification or repair (if any) is currently installed on the airplane and

do the applicable inspections in accordance with the appropriate Figure listed in the tables below.

Refer to Table 1 for Group 1 airplanes, Table 2 for Group 2 airplanes, and Table 3 for Group 3, 4

and 5 airplanes. Refer to FIGURE 4 that shows the inspection areas.

Group 1:

Table 1: Inspection

Condition Action - Inspection

Do a HFEC inspection and detailed inspection for any crack

in the bearstrap and skin assembly in accordance with FIGURE

5 and FIGURE 6.

Airplanes without a preventive modification or

repair installed in accordance with the original

issue or Revision 1, 2 or 3 of this service bulletin

Do a HFEC inspection and detailed inspection for any crack

in the bearstrap in accordance

with FIGURE 5, and do a LFEC

inspection of the skin assembly

and bearstrap, and a detailed

inspection of the skin assembly

for any crack in accordance with

FIGURE 7.

Airplanes with preventive modification installed

in accordance with the original issue of this service bulletin.

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Group 1:

Table 1: Inspection

Condition Action - Inspection

Do a HFEC inspection and detailed inspection for any crack

in the bearstrap in accordance

with FIGURE 5, and do an

LFEC inspection of the skin assembly and bearstrap, and a

detailed inspection of the skin

assembly for any crack in accordance with FIGURE 8.

Airplanes with preventive modification installed

in accordance with Revisions 1, 2 or 3 of this

service bulletin.

Do a HFEC inspection and detailed inspection for any crack

in the bearstrap in accordance

with FIGURE 5, and do a detailed inspection of the skin assembly, and a LFEC inspection

of the skin assembly and

bearstrap for any crack in accordance with FIGURE 10.

Airplanes with repair installed in accordance with

the original issue of this service bulletin.

Group 2:

Table 2: Inspection

Condition Action - Inspection

Do a HFEC inspection and detailed inspection for any crack in the bearstrap

and skin assembly in accordance with

FIGURE 5 and FIGURE 6.

Airplanes without a preventive modification

or repair installed in accordance with the

original issue or Revision 1, 2 or 3 of this

service bulletin

Do a HFEC inspection and detailed inspection for any crack in the bearstrap

in accordance with FIGURE 5, and do a

LFEC inspection of the skin assembly

and bearstrap and a detailed inspection

of the skin assembly for any crack in

accordance with FIGURE 7.

Airplanes with preventive modification installed in accordance with the original issue of this service bulletin.

Do a HFEC inspection and detailed inspection for any crack in the bearstrap

in accordance with FIGURE 5, and do a

LFEC inspection of the skin assembly

and bearstrap and a detailed inspection

of the skin assembly for any crack in

accordance with FIGURE 8.

Airplanes with preventive modification installed in accordance with Revisions 1, 2

or 3 of this service bulletin.

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Group 2:

Table 2: Inspection

Condition Action - Inspection

Do a HFEC inspection and detailed inspection for any crack in the bearstrap

in accordance with FIGURE 5, and do a

detailed inspection of the skin assembly

and a LFEC inspection of the skin assembly and bearstrap for any crack in accordance with FIGURE 11.

Airplanes with repair installed in accordance with the original issue of this service

bulletin.

Group 3-5:

Table 3: Inspection

Condition Action - Inspection

Do a HFEC and detailed inspection for

any crack in the bearstrap in accordance

with FIGURE 5, and do a LFEC inspection of the skin assembly and bearstrap,

and a detailed inspection of the skin assembly for any crack in accordance with

FIGURE 9.

All airplanes.

a. Group 1-2:

For airplanes that do not have a repair or preventive installed in accordance with the original

issue or revision 1, 2 or 3 of this service bulletin and no cracks are found in the skin assembly

or bearstrap, do repeat inspections at the times given in Paragraph 1.E., Compliance or do

the preventive modification as follows:

(1) Remove all fasteners that will be common to the 65C20843-35 or 65C20843-36 preventive

modification doubler.

(2) Group 1:

Do an open hole High Frequency Eddy Current (HFEC) inspection in accordance with

737 NDT Part 6, 51-00-00, Figure 16 for any crack at all fastener holes that will be common

to the new preventive modification (or repair) given in 65C20843-35 .

(a) If no crack is found, install the preventive modification in accordance with

65C20843-35 and Paragraph 3.A., General Information, Note 13.

(b) If any crack is found in the skin assembly or bearstrap, but not both, repair in

accordance with Part 2, step 1.e.

(c) If any crack is in both the skin assembly and bearstrap, repair in accordance with

Part 2, step 1.f.

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(3) Group 2:

Do an open hole HFEC inspection in accordance with 737 NDT Part 6, 51-00-00, Figure

16 for any crack in all fastener holes that will be common to the new preventive modification

given in 65C20843-36 .

(a) If no crack is found, install the preventive modification in accordance with

65C20843-36 and Paragraph 3.A., General Information, Note 13.

(b) If any crack is found in the skin assembly or bearstrap, but not both, repair in

accordance with Part 2, step 1.e.

(c) If any crack is in both the skin assembly and bearstrap, repair in accordance with

Part 2, step 1.f.

b. Group 1-2:

For airplanes that have a repair installed in accordance with the original issue of this service

bulletin and no cracks are found in the skin assembly and bearstrap, do repeat inspections

at the times given in Paragraph 1.E., Compliance or remove the existing repair and install a

new repair as follows:

(1) Remove the previous repair parts.

(2) Cut out the previously stop drilled cracks in accordance with FIGURE 12.

(a) If the cutout is larger than the maximum cutout area given in FIGURE 12, contact

The Boeing Company for repair instructions and do the repair.

(3) If the cutout is in the skin assembly or bearstrap, but not both, repair in accordance with

Part 2, step 1.e.

(4) If the cutout is in the skin assembly and bearstrap, repair in accordance with Part 2, step

1.f.

c. Group 1-2:

For airplanes that have a preventive modification installed in accordance with the original

issue, Revision 1, 2 or 3 of this service bulletin and no cracks are found in the skin assembly

and bearstrap, do the repeat inspections at times given in Paragraph 1.E., Compliance or do

the preventive modification as follows:

(1) Remove the previous preventive modification parts and all fasteners that will be common

to the 65C20843-35 or 65C20843-36 preventive modification doubler.

(2) Group 1:

Do an open hole HFEC inspection in accordance with 737 NDT Part 6, 51-00-00 Figure

16 for any crack in all fastener holes that will be common to the new 65C20843-35

preventive modification doubler.

(a) If no crack is found, install the new preventive modification in accordance with

65C20843-35 and Paragraph 3.A., General Information, Note 13. Make sure any

fillers fabricated in FIGURE 12 are installed wet with BMS 5-95 sealant at the same

time as the preventive modification. Refer to SOPM 20-50-19 as an accepted

procedure. It is acceptable to oversize existing holes in accordance with Paragraph

3.A., General Information, Note 14.

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(b) If any crack is found in the skin assembly or bearstrap, but not both, repair in

accordance with Part 2, step 1.e.

(c) If any crack is found in the skin assembly and bearstrap, repair in accordance with

Part 2, step 1.f.

(3) Group 2:

Do an open hole HFEC inspection in accordance with 737 NDT Part 6, 51-00-00 Figure

16 for any crack in all fastener holes that will be common to the new 65C20843-36

preventive modification doubler (or repair).

(a) If no crack is found, install the new preventive modification in accordance with

65C20843-36 and Paragraph 3.A., General Information, Note 13. Make sure any

fillers fabricated in FIGURE 12 are installed wet with BMS 5-95 sealant at the same

time as the preventive modification. Refer to SOPM 20-50-19 as an accepted

procedure. It is acceptable to oversize existing holes in accordance with Paragraph

3.A., General Information, Note 14.

(b) If any crack is found in the skin assembly or bearstrap, but not both, repair in

accordance with Part 2, step 1.e.

(c) If any crack is found in the skin assembly and bearstrap, repair in accordance with

Part 2, step 1.f.

d. Group 3-5:

If no crack is found in the skin assembly, or bearstrap, do repeat inspections at the times

given in Paragraph 1.E., Compliance or do the preventive modification as follows:

(1) Remove the external tripler 65-45800-1115 production modification parts.

(2) Group 3:

Do an open hole HFEC inspection in accordance with 737 NDT Part 6, 51-00-00 Figure

16 for any crack in all fastener holes that will be common to the new preventive modification

(or repair) given in 65C20843-35.

(a) If no crack is found, install the preventive modification in accordance with

65C20843-35 and Paragraph 3.A., General Information, Note 13.

(b) If any crack is found in the skin or bearstrap, but not both, repair in accordance with

Part 2, step 1.e.

(c) If any crack is found in both the skin and bearstrap, repair in accordance with Part

2, step 1.f.

(3) Group 4:

Do an open hole HFEC inspection in accordance with 737 NDT Part 6, 51-00-00 Figure

16 for any crack in all fastener holes that will be common to the new preventive modification

(or repair) given in 65C20843-36.

(a) If no crack is found, install the preventive modification in accordance with

65C20843-36 and Paragraph 3.A., General Information, Note 13.

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(b) If any crack is found in the skin or bearstrap, but not both, repair in accordance with

Part 2, step 1.e.

(c) If any crack is found in both the skin and bearstrap, repair in accordance with Part

2, step 1.f.

(4) Group 5:

Do an open hole HFEC inspection in accordance with 737 NDT Part 6, 51-00-00 Figure

16 for any crack in all fastener holes that will be common to the new preventive modification

(or repair) given in 65C20843-39.

(a) If no crack is found, install the preventive modification in accordance with

65C20843-39 and Paragraph 3.A., General Information, Note 13.

(b) If any crack is found in the skin or bearstrap, but not both, repair in accordance with

Part 2, step 1.e.

(c) If any crack is found in both the skin and bearstrap, repair in accordance with Part

2, step 1.f.

e. If any crack is found in either the skin assembly or bearstrap, but not both:

(1) Remove the previous modification or repair parts (if applicable).

(2) Cut out all cracks found in accordance with FIGURE 12.

NOTE: Existing cracks that have been previously stop-drilled must be cut out in

accordance with FIGURE 12.

(a) If the cutout is larger than the maximum cutout area shown in FIGURE 12, contact

The Boeing Company for repair instructions and do the repair.

(3) Group 1, 3:

Do an open hole HFEC inspection in accordance with 737 NDT Part 6, 51-00-00 Figure

16 for any crack in all fastener holes that will be common to the new repair given in

65C20843-35.

(a) If no crack is found, install the repair in accordance with Boeing drawing 65C20843

Sheet 3 and Paragraph 3.A., General Information, Note 13. Reference kit

65C20843-35. Make sure any fillers fabricated in FIGURE 12 are installed at the

same time as the repair. For Group 1 airplanes that had an existing repair or

preventive modification installed, it is acceptable to oversize existing holes in

accordance with Paragraph 3.A., General Information, Note 14.

(b) If any additional crack is found and is within the maximum cutout area shown in

FIGURE 12:

1) Remove the damage in accordance with FIGURE 12.

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2) Install the repair in accordance with Boeing drawing 65C20843 Sheet 3.

Reference kit 65C20843-35 and Paragraph 3.A., General Information, Note 13.

Make sure any fillers fabricated in FIGURE 12 are installed at the same time as

the repair. For Group 1 airplanes that had an existing repair or preventive

modification installed, it is acceptable to oversize existing holes in accordance

with Paragraph 3.A., General Information, Note 14.

(c) If any additional crack is found and is not within the maximum cutout area shown in

Figure 12, contact The Boeing Company for repair instructions and do the repair.

(4) Group 2, 4:

Do an open hole HFEC inspection in accordance with 737 NDT Part 6, 51-00-00 Figure

16 for any crack in all fastener holes that will be common to the new repair given in

65C20843-36.

(a) If no crack is found, install the repair in accordance with Boeing drawing 65C20843

Sheet 3 and Paragraph 3.A., General Information, Note 13. Reference kit

65C20843-36. Make sure any fillers fabricated in FIGURE 12 are installed wet with

BMS 5-95 sealant at the same time as the repair. Refer to SOPM 20-50-19 as an

accepted procedure. For Group 2 airplanes that had an existing repair or preventive

modification installed, it is acceptable to oversize existing holes in accordance with

Paragraph 3.A., General Information, Note 14.

(b) If any additional crack is found and is within the maximum cutout area shown in

FIGURE 12:

1) Remove the damage in accordance with FIGURE 12.

2) Install the repair in accordance with Boeing drawing 65C20843 Sheet 3 and

Paragraph 3.A., General Information, Note 13. Reference kit 65C20843-36.

Make sure any fillers fabricated in FIGURE 12 are installed wet with BMS 5-95

sealant at the same time as the repair. Refer to SOPM 20-50-19 as an accepted

procedure. For Group 2 airplanes that had an existing repair or preventive

modification installed, it is acceptable to oversize existing holes in accordance

with Paragraph 3.A., General Information, Note 14.

(c) If any additional crack is found and is not within the maximum cutout area shown in

FIGURE 12, contact The Boeing Company for repair instructions and do the repair.

(5) Group 5:

Do an open hole HFEC inspection in accordance with 737 NDT Part 6, 51-00-00 Figure

16 for any crack in all fastener holes that will be common to the new repair given in

65C20843-39.

(a) If no crack is found, install the repair in accordance with Boeing drawing 65C20843

Sheet 3 and Paragraph 3.A., General Information, Note 13. Reference kit

65C20843-39. Make sure any fillers fabricated in FIGURE 12 are installed wet with

BMS 5-95 sealant at the same time as the repair. Refer to SOPM 20-50-19 as an

accepted procedure.

(b) If any additional crack is found and is within the maximum cutout area shown in

FIGURE 12:

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1) Remove the damage in accordance with FIGURE 12.

2) Install the repair in accordance with Boeing drawing 65C20843 Sheet 3 and

Paragraph 3.A., General Information, Note 13. Reference kit 65C20843-39.

Make sure any fillers fabricated in FIGURE 12 are installed wet with BMS 5-95

sealant at the same time as the repair. Refer to SOPM 20-50-19 as an accepted

procedure.

(c) If any additional crack is found and is not within the maximum cutout area shown in

FIGURE 12, contact The Boeing Company for repair instructions and do the repair.

f. If any crack is found in both the skin assembly and bearstrap:

(1) Remove the previous modification or repair parts (if applicable).

(2) Cut out the cracks in accordance with FIGURE 12.

NOTE: Existing cracks that have been previously stop-drilled must be cut out in

accordance with Figure 12.

(a) If the cutout is larger than the maximum cutout area shown in FIGURE 12, contact

The Boeing Company for repair instructions and do the repair.

(3) Group 1, 3:

Do an open hole HFEC inspection in accordance with 737 NDT Part 6, 51-00-00 Figure

16 for any crack in all fastener holes that will be common to the new repair given in

65C20843-37.

(a) If no crack is found, install the repair in accordance with drawing 65C20843 Sheet

3 and Paragraph 3.A., General Information, Note 13. Reference kit 65C20843-37.

Make sure any fillers fabricated in FIGURE 12 are installed wet with BMS 5-95 sealant

at the same time as the repair. Refer to SOPM 20-50-19 as an accepted procedure.

For Group 1 airplanes that had an existing repair or preventive modification installed,

it is acceptable to oversize existing holes in accordance with Paragraph 3.A., General

Information, Note 14.

(b) If any additional crack is found and is within the maximum cutout area shown in

FIGURE 12:

1) Remove the damage as shown in FIGURE 12.

2) Install the repair in accordance with Boeing drawing 65C20843 Sheet 3 and

Paragraph 3.A., General Information, Note 13. Reference kit 65C20843-37.

Make sure any fillers fabricated in FIGURE 12 are installed wet with BMS 5-95

sealant at the same time as the repair. Refer to SOPM 20-50-19 as an accepted

procedure.

(c) If any additional crack is found and is not within the maximum cutout area shown in

FIGURE 12, contact The Boeing Company for repair instructions and do the repair.

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(4) Group 2, 4:

Do an open hole HFEC inspection in accordance with 737 NDT Part 6, 51-00-00 Figure

16 for any crack in all fastener holes that will be common to the new repair given in

65C20843-38.

(a) If no crack is found, install the repair in accordance with drawing 65C20843 Sheet

3 and Paragraph 3.A., General Information, Note 13. Reference kit 65C20843-38.

Make sure any fillers fabricated in FIGURE 12 are installed wet with BMS 5-95 sealant

at the same time as the repair. Refer to SOPM 20-50-19 as an accepted procedure.

For Group 2 airplanes that had an existing repair or preventive modification installed,

it is acceptable to oversize existing holes in accordance with Paragraph 3.A., General

Information, Note 14.

(b) If any additional crack is found and is within the maximum cutout area shown in

FIGURE 12:

1) Remove the damage in accordance with FIGURE 12.

2) Install the repair in accordance with Boeing drawing 65C20843 Sheet 3 and

Paragraph 3.A., General Information, Note 13. Reference kit 65C20843-38.

Make sure any fillers fabricated in FIGURE 12 are installed wet with BMS 5-95

sealant at the same time as the repair. Refer to SOPM 20-50-19 as an accepted

procedure. For Group 1 airplanes that had an existing repair or preventive

modification installed, it is acceptable to oversize existing holes in accordance

with Paragraph 3.A., General Information, Note 14.

(c) If any additional crack is found and is not within the maximum cutout area shown in

FIGURE 12, contact The Boeing Company for repair instructions and do the repair.

(5) Group 5:

Do an open hole HFEC inspection in accordance with 737 NDT Part 6, 51-00-00 Figure

16 for any crack in all fastener holes that will be common to the new repair given in

65C20843-40.

(a) If no crack is found, install the repair in accordance with drawing 65C20843 Sheet

3 and Paragraph 3.A., General Information, Note 13. Reference kit 65C20843-40.

Make sure any fillers fabricated in FIGURE 12 are installed wet with BMS 5-95 sealant

at the same time as the repair. Refer to SOPM 20-50-19 as an accepted procedure.

(b) If any additional crack is found and is within the maximum cutout area shown in

FIGURE 12:

1) Remove the damage in accordance with FIGURE 12.

2) Install the repair in accordance with Boeing drawing 65C20843 Sheet 3 and

Paragraph 3.A., General Information, Note 13. Reference kit 65C20843-40.

Make sure any fillers fabricated in FIGURE 12 are installed wet with BMS 5-95

sealant at the same time as the repair. Refer to SOPM 20-50-19 as an accepted

procedure.

(c) If any additional crack is found and is not within the maximum cutout area shown in

FIGURE 12, contact The Boeing Company for repair instructions and do the repair.

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g. Accomplishment of the repair or preventive modification in accordance with 65C20843-35,

65C20843-36, 65C20843-37, 65C20843-38, 65C20843-39, 65C20843-40 as given in paragraph

a, c, d, e and f above terminates the inspection of this service bulletin. Post repair or preventive

modification inspections are provided in Paragraph 1.E, Compliance Table 3 and Table 4 as

applicable.

Group 1-5:

PART 3 - POST REPAIR AND POST PREVENTIVE MODIFICATION INSPECTIONS

1. Group 1-2:

Do an Internal HFEC Inspection for any crack in the Bearstrap and Skin Assembly and an Internal

General Visual Inspection for any crack in the frame outer chord in accordance with FIGURE 13

(OPTION A) at the times specified in Paragraph 1.E., Compliance, Table 3 or

do an External LFEC Inspection for any crack in the Bearstrap and Skin Assembly in accordance

with FIGURE 14 (OPTION B) at the times specified in Paragraph 1.E., Compliance, Table 3.

If any crack is found, contact The Boeing Company for repair instructions and do the repair.

2. Group 3-5:

Do an Internal HFEC Inspection for any crack in the Bearstrap and Skin Assembly and an Internal

General Visual Inspection for any crack in the frame outer chord in accordance with FIGURE 13

(OPTION A) at the times specified in Paragraph 1.E., Compliance, Table 4 or

do an External LFEC Inspection for any crack in the Bearstrap and Skin Assembly in accordance

with FIGURE 14 (OPTION B) at the times specified in Paragraph 1.E., Compliance, Table 4.

If any crack is found, contact The Boeing Company for repair instructions and do the repair.

Group 1-5:

PART 4 - CLOSE ACCESS

1. Put the airplane back to a serviceable condition.

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FIGURE 1: THIS FIGURE HAS BEEN REMOVED

(SHEET 1 OF 1)

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FIGURE 2: THIS FIGURE HAS BEEN REMOVED

(SHEET 1 OF 1)

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FIGURE 3: THIS FIGURE HAS BEEN REMOVED

(SHEET 1 OF 1)

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BOEING SERVICE BULLETIN 737-53-1058
This Figure applies only to: Group 1-5.

FIGURE 4: AIRSTAIR STOWAGE DOORWAY CORNER - LOCATION OF INSPECTION AREAS

(SHEET 1 OF 2)

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BOEING SERVICE BULLETIN 737-53-1058
The step numbers shown below agree with the numbers shown in the circle symbols in the figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

Eddy current in- - - (a)

spection area

1 Locate

Detailed inspection - - (b)

area

2 Locate

(a) Area to be inspected using eddy current inspections.

(b) Area to be inspected using detailed inspections.

FIGURE 4: AIRSTAIR STOWAGE DOORWAY CORNER - LOCATION OF INSPECTION AREAS

(SHEET 2 OF 2)

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This Figure applies only to: Group 1-5.

FIGURE 5: AIRSTAIR STOWAGE DOORWAY CORNER - INTERNAL INSPECTION OF THE BEARSTRAP

(SHEET 1 OF 2)

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BOEING SERVICE BULLETIN 737-53-1058
The step numbers shown below agree with the numbers shown in the circle symbols in the figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Inspect Bearstrap - - (a)

2 Inspect Bearstrap - - (b)

(a) Do an internal HFEC surface inspection for any crack in the bearstrap within the area shown in accordance with 737 NDT Part 6, 51-00-00, Figure 4 or Figure 23.

(b) Do an Internal Detailed Inspection for any crack in the visible inboard side of the bearstrap within

the area shown.

FIGURE 5: AIRSTAIR STOWAGE DOORWAY CORNER - INTERNAL INSPECTION OF THE BEARSTRAP

(SHEET 2 OF 2)

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This Figure applies only to: Group 1-2.

FIGURE 6: AIRSTAIR STOWAGE DOORWAY CORNER INSPECTION - NO PREVENTIVE MODIFICATION

OR EXTERNAL TRIPLER INSTALLED

(SHEET 1 OF 2)

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BOEING SERVICE BULLETIN 737-53-1058
The step numbers shown below agree with the numbers shown in the circle symbols in the figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Inspect Skin Assembly - - (a)

2 Inspect Skin Assembly - - (b)

(a) Do an external HFEC inspection for any crack in the skin assembly surface in accordance with 737

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

(b) Do an external Detailed Inspection for any crack in the skin assembly within the inspection area shown.

FIGURE 6: AIRSTAIR STOWAGE DOORWAY CORNER INSPECTION - NO PREVENTIVE MODIFICATION

OR EXTERNAL TRIPLER INSTALLED

(SHEET 2 OF 2)

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BOEING SERVICE BULLETIN 737-53-1058
This Figure applies only to: Group 1-2.

FIGURE 7: AIRSTAIR STOWAGE DOORWAY CORNER INSPECTION - PREVENTIVE MODIFICATION

TRIPLER INSTALLED PER ORIGINAL ISSUE OF THIS SERVICE BULLETIN

(SHEET 1 OF 2)

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BOEING SERVICE BULLETIN 737-53-1058
The step numbers shown below agree with the numbers shown in the circle symbols in the figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Inspect Bearstrap - - (a)

Skin Assembly - - (a)

2 Inspect Skin Assembly - - (b)

(a) Do an external LFEC inspection for any crack in the surface of the skin assembly and bear strap through

an external preventive modification tripler installed per the original issue of this service bulletin in accordance

with 737 NDT Manual Part 6, 53-30-00, Figure 5.

(b) Do an external Detailed Inspection for any crack in the visible skin assembly within the inspection area

shown.

FIGURE 7: AIRSTAIR STOWAGE DOORWAY CORNER INSPECTION - PREVENTIVE MODIFICATION

TRIPLER INSTALLED PER ORIGINAL ISSUE OF THIS SERVICE BULLETIN

(SHEET 2 OF 2)

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BOEING SERVICE BULLETIN 737-53-1058
This Figure applies only to: Group 1-2.

FIGURE 8: AIRSTAIR STOWAGE DOORWAY CORNER INSPECTION - PREVENTIVE MODIFICATION

TRIPLER INSTALLED PER REVISION 1, 2 OR 3 OF THIS SERVICE BULLETIN

(SHEET 1 OF 2)

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66 of 81

BOEING SERVICE BULLETIN 737-53-1058
The step numbers shown below agree with the numbers shown in the circle symbols in the figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Inspect Bearstrap - - (a)

Skin Assembly - - (a)

2 Inspect Skin Assembly - - (b)

(a) Do an external LFEC inspection for any crack in the surface of the skin assembly and bearstrap through

an external preventive modification tripler installed per Revision 1, 2 or 3 of this service bulletin in accordance with 737 NDT Manual Part 6, 53-30-00, Figure 5.

(b) Do an external Detailed Inspection for any crack in the skin assembly within the inspection area shown.

FIGURE 8: AIRSTAIR STOWAGE DOORWAY CORNER INSPECTION - PREVENTIVE MODIFICATION

TRIPLER INSTALLED PER REVISION 1, 2 OR 3 OF THIS SERVICE BULLETIN

(SHEET 2 OF 2)

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BOEING SERVICE BULLETIN 737-53-1058
This Figure applies only to: Group 3-5.

FIGURE 9: AIRSTAIR STOWAGE DOORWAY CORNER INSPECTION - PRODUCTION MODIFICATION

EXTERNAL TRIPLER INSTALLED

(SHEET 1 OF 2)

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68 of 81

BOEING SERVICE BULLETIN 737-53-1058
The step numbers shown below agree with the numbers shown in the circle symbols in the figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Inspect Bearstrap - - (a)

Skin Assembly - - (a)

2 Inspect Skin Assembly - - (b)

(a) Do external LFEC inspection for any crack in the surface of the skin assembly and bearstrap through the

65-45800-1115 external production modification tripler in accordance with 737 NDT Manual Part 6, 53-

30-00, Figure 5.

(b) Do an external Detailed Inspection for any crack in the skin assembly within the inspection area shown.

FIGURE 9: AIRSTAIR STOWAGE DOORWAY CORNER INSPECTION - PRODUCTION MODIFICATION

EXTERNAL TRIPLER INSTALLED

(SHEET 2 OF 2)

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BOEING SERVICE BULLETIN 737-53-1058
This Figure applies only to: Group 1.

FIGURE 10: AIRSTAIR STOWAGE DOORWAY CORNER INSPECTION - REPAIR INSTALLED AT THE

ORIGINAL ISSUE OF THIS SERVICE BULLETIN

(SHEET 1 OF 3)

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BOEING SERVICE BULLETIN 737-53-1058
FIGURE 10: AIRSTAIR STOWAGE DOORWAY CORNER INSPECTION - REPAIR INSTALLED AT THE

ORIGINAL ISSUE OF THIS SERVICE BULLETIN

(SHEET 2 OF 3)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

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71 of 81

BOEING SERVICE BULLETIN 737-53-1058
The step numbers shown below agree with the numbers shown in the circle symbols in the figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Inspect Skin Assembly - - (a)

2 Inspect Skin Assembly - - (b)

Bearstrap - - (b)

(a) Do an external Detailed Inspection for any crack in the skin assembly within the inspection

area shown.

(b) Do an external LFEC inspection for any crack in the skin assembly and bearstrap within the

inspection area shown in accordance with 737 NDT Manual Part 6, 53-30-00, Figure 5.

FIGURE 10: AIRSTAIR STOWAGE DOORWAY CORNER INSPECTION - REPAIR INSTALLED AT THE

ORIGINAL ISSUE OF THIS SERVICE BULLETIN

(SHEET 3 OF 3)

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BOEING SERVICE BULLETIN 737-53-1058
This Figure applies only to: Group 2.

FIGURE 11: AIRSTAIR STOWAGE DOORWAY CORNER INSPECTION - REPAIR INSTALLED AT THE

ORIGINAL ISSUE OF THIS SERVICE BULLETIN

(SHEET 1 OF 3)

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BOEING SERVICE BULLETIN 737-53-1058
FIGURE 11: AIRSTAIR STOWAGE DOORWAY CORNER INSPECTION - REPAIR INSTALLED AT THE

ORIGINAL ISSUE OF THIS SERVICE BULLETIN

(SHEET 2 OF 3)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

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Original Issue: April 04, 1980

Revision 4 January 09, 2014 737-53-1058

74 of 81

BOEING SERVICE BULLETIN 737-53-1058
The step numbers shown below agree with the numbers shown in the circle symbols in the figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Inspect Skin Assembly - - (a)

2 Inspect Skin Assembly - - (b)

Bearstrap - - (b)

(a) Do an external Detailed Inspection for any crack in the skin assembly within the inspection area

shown.

(b) Do an external LFEC inspection for any crack in the skin assembly and bearstrap within the inspection area shown in accordance with 737 NDT Manual Part 6, 53-30-00, Figure 5.

FIGURE 11: AIRSTAIR STOWAGE DOORWAY CORNER INSPECTION - REPAIR INSTALLED AT THE

ORIGINAL ISSUE OF THIS SERVICE BULLETIN

(SHEET 3 OF 3)

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PROPRIETARY - Copyright © Unpublished

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BOEING SERVICE BULLETIN 737-53-1058
This Figure applies only to: Group 1-5.

FIGURE 12: AIRSTAIR STOWAGE DOORWAY CORNER - AREA OF CUTOUT FOR CRACK REMOVAL

(SHEET 1 OF 2)

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BOEING SERVICE BULLETIN 737-53-1058
The step numbers shown below agree with the numbers shown in the circle symbols in the figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Cut Skin Assembly - - (a)

Bearstrap - - (a)

2 Inspect Cutout - - (b)

3 Cut Skin Assembly - - (c)

Bearstrap - - (c)

4 Make Filler 2024-T3 2 (d) (e)

Chemical Conversion Type 2, Class A 1 (e)

Coating

5 Apply

BMS 10-11, Type 1 (f)

1

6 Apply Primer

(a) Cut out the crack in the structure with a minimum 0.5 inch radius. Cut must not exceed the maximum

dimension shown. Maintain 2D edge margin to adjacent fasteners. For skin 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 Part 6, 51-00-00, Figure 4, or Figure 23.

(c) If there are no crack indications, oversize the cutout by a minimum of 0.04 inches. Maintain a

minimum of 63 RMS finish on the cutout and 2D edge margin for adjacent fasteners.

(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 12: AIRSTAIR STOWAGE DOORWAY CORNER - AREA OF CUTOUT FOR CRACK REMOVAL

(SHEET 2 OF 2)

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BOEING SERVICE BULLETIN 737-53-1058
This Figure applies only to: Group 1-5.

FIGURE 13: POST REPAIR AND POST PREVENTIVE MODIFICATION INSPECTION - OPTION A

(SHEET 1 OF 2)

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BOEING SERVICE BULLETIN 737-53-1058
The step numbers shown below agree with the numbers shown in the circle symbols in the figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Inspect Frame - - (a)

2 Inspect Bearstrap - - (b)

Skin Assembly - - (b)

(a) Do an internal General Visual Inspection for any crack in the frame.

(b) Do a internal HFEC inspection for any crack in the Skin Assembly and Bearstrap in accordance with 737

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

FIGURE 13: POST REPAIR AND POST PREVENTIVE MODIFICATION INSPECTION - OPTION A

(SHEET 2 OF 2)

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BOEING SERVICE BULLETIN 737-53-1058
This Figure applies only to: Group 1-5.

FIGURE 14: POST REPAIR AND POST PREVENTIVE MODIFICATION INSPECTION - OPTION B

(SHEET 1 OF 2)

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80 of 81

BOEING SERVICE BULLETIN 737-53-1058
The step numbers shown below agree with the numbers shown in the circle symbols in the figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Inspect Bearstrap - - (a)

Skin Assembly - - (a)

(a) Do a external Low Frequency Eddy Current (LFEC) inspection for any crack in the Skin Assembly and

Bearstrap in accordance with 737 NDT Manual Part 6, 53-30-00, Figure 5.

FIGURE 14: POST REPAIR AND POST PREVENTIVE MODIFICATION INSPECTION - OPTION B

(SHEET 2 OF 2)

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BOEING SERVICE BULLETIN 737-53-1058