Commercial 

Airplanes 747

Service Bulletin

ALERT

Number: 747-53A2088

Original Issue: March 08, 1974

Revision 4: January 11, 2013

ATA System: 5300

SUBJECT: FUSELAGE - Body Station 760 or 780 - Frame to Tension Tie Joint - Inspection /

Modification

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Unpublished Work.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, DreamlinerTM,

BBJ, DC-8, DC-9, DC-10, KC-10, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8A, 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. BOEING is a trademark of Boeing Management

Company.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

1 of 62

5.0
Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

2 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT

BLANK PAGE
Table of Contents

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

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

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

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

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

2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

B. Concurrent Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

C. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

E. Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

H. Weight and Balance Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

1. Existing Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

2. Data Supplied with this Service Bulletin: . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

3. Installation Drawings Used in the Preparation of this Service Bulletin: . . . . . . . . . . . 23

K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

M. Software Accomplishment Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

2. MATERIAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

A. Material - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

C. Parts Necessary for Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

1. Kits/Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

2. Parts and Materials Supplied by the Operator . . . . . . . . . . . . . . . . . . . . . . . . 26

3. Parts Modified and Reidentified . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

4. Parts Removed and Not Replaced . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

D. Parts Necessary to Change Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

E. Special Tooling - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

F. Special Tooling Necessary to do this Service Bulletin . . . . . . . . . . . . . . . . . . . . . . . 27

3. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

B. WORK INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

FIGURE 1: UNMODIFIED TENSION TIE INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . 33

FIGURE 2: MODIFIED TENSION TIE INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

FIGURE 3: FRAME TENSION TIE MODIFICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

FIGURE 4: THIS FIGURE IS DELETED (REVISION 4) . . . . . . . . . . . . . . . . . . . . . . . . . 43

FIGURE 5: THIS FIGURE IS DELETED (REVISION 4) . . . . . . . . . . . . . . . . . . . . . . . . . 44

FIGURE 6: THIS FIGURE IS DELETED (REVISION 4) . . . . . . . . . . . . . . . . . . . . . . . . . 45

FIGURE 7: ALTERNATIVE MODIFICATION [Group 1] . . . . . . . . . . . . . . . . . . . . . . . . . . 46

FIGURE 8: ALTERNATIVE MODIFICATION [Group 2] . . . . . . . . . . . . . . . . . . . . . . . . . . 51

FIGURE 9: ALTERNATIVE MODIFICATION [Group 3] . . . . . . . . . . . . . . . . . . . . . . . . . . 56

APPENDIX A: ADDENDUM - FLIGHT SAFETY SECTION . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

3 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

4 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT

BLANK PAGE
Commercial 

Airplanes 747

Service Bulletin

ALERT

Revision Transmittal Sheet Number: 747-53A2088

Original Issue: March 08, 1974

Revision 4: January 11, 2013

ATA System: 5300

SUBJECT: FUSELAGE - Body Station 760 or 780 - Frame to Tension Tie Joint - Inspection /

Modification

This revision includes all pages of the service bulletin.

COMPLIANCE INFORMATION RELATED TO THIS REVISION

More work is necessary on all airplanes that have not been modified in accordance with the original issue,

Revision 1, Revision 2 or Revision 3 of this service bulletin. Do a surface High Frequency Eddy Current (HFEC)

inspection of the radius common to the aft channel of the tension tie at the next inspection that is scheduled to

be done in accordance with Paragraph 1.E., Compliance and accomplish the tension tie modification at the time

given in Paragraph 1.E., Compliance.

Federal Aviation Administration (FAA) Airworthiness Directive AD 84-19-01 is related to this service bulletin.

REASON FOR REVISION

This revision is sent to add a surface High Frequency Eddy Current (HFEC) inspection of the upper and lower

radius common to the aft channel of the tension tie and to add a compliance time for the accomplishment of the

tension tie modification.

These sections were changed:

1. Summary Section: Added new Background information related to the revision. Updated Action section

to reflect new requirements. Added Federal Aviation Administration (FAA) Airworthiness Directive

information to the compliance section. Added new industry support information. Revised Summary

illustration text to reflect changed actions.

2. In Paragraph 1.C., Reason: Added new background information related to the revision.

3. In Paragraph 1.D., Description: Updated the action descriptions to reflect new requirements, added

"More work" statement and added maintenance zone tables.

4. In Paragraph 1.E., Compliance: Updated compliance times and added new compliance tables.

5. In Paragraph 1.F., Approval: Is updated and a new approval statement added.

6. In Paragraph 1.G., Manpower: Updated manpower estimate.

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

5 of 62
7. In Paragraph 1.H., Weight and Balance Changes: Updated weight and balance and added new weight

and balance tables.

8. In Paragraph 1.J., References: Added new references related to this revision.

9. In Paragraph 1.K., Publications Affected: Added statement for damage tolerance inspections.

10. In Paragraph 2.B., Industry Support Information: Added new industry support information.

11. In Paragraph 3.A., General Information: Updated general notes to current requirements.

12. In Paragraph 3.B., Work Instructions, PART I - Flight Safety Inspection Program: Added a new surface

High Frequency Eddy Current (HFEC) inspection of tension ties. Removed compliance times and

removed the reference to report any discrepancies in the Flight Safety Addendum.

13. Figure 1: Added a new detailed inspection and surface High Frequency Eddy Current (HFEC) inspection

of tension ties.

14. Figure 2: Updated the AMM reference for ceiling panel removal. Removed the word optional from the

view A-A illustration. Changed close visual inspection to a detailed inspection.

15. Figure 3: Added a new section view to the illustration.

16. Figure 4, Figure 5 and Figure 6 logic diagrams have been deleted. The flight safety and economic

based inspection program information can be found in Paragraph 1.E., Compliance.

17. Figure 7, Figure 8 and Figure 9: Added and removed typical measurements from the illustrations.

18. APPENDIX A: In table 1 the inspection method and repeat inspection threshold times have been

updated.

19. ADDENDUM: Removed the evaluation form from the addendum section.

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

of important changes.

Pages with no vertical lines have no important changes.

REVISION HISTORY

Original Issue: March 08, 1974

Revision 1: May 01, 1974

Revision 2: August 26, 1983

Revision 3: September 08, 1994

Revision 4: January 11, 2013

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

6 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
Commercial 

Airplanes 747

Service Bulletin

ALERT

Summary Number: 747-53A2088

Original Issue: March 08, 1974

Revision 4: January 11, 2013

ATA System: 5300

SUBJECT: FUSELAGE - Body Station 760 or 780 - Frame to Tension Tie Joint - Inspection /

Modification

THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH

1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO

THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO

THE NEW OWNER.

CONCURRENT REQUIREMENTS

None.

BACKGROUND

Accomplishment of the inspection program detailed in this bulletin will make sure the structural integrity of the

Body Station 760 or 780 (as applicable) tension tie throughout the operational life of the airplane. Undetected

tension tie cracking could eventually result in in-flight depressurization of the airplane and the inability to withstand

current regulatory failsafe loads.

Inspection of the fatigue test airplane after the equivalent of 12,000 flight-cycles revealed a crack in the BS 760

tension tie as a result of bending due to cabin pressurization.

Structural reassessment of the 747 airplane has been conducted under the requirements of Federal Aviation

Administration (FAA) Advisory Circular 91-56, in accordance with Federal Aviation Regulation (FAR) 25.571 as

amended in 1978, to ensure the safe operation of 747 airplanes throughout their operational life. As a result of

this reassessment, the BS 760 or 780 (as applicable) tension tie has been determined to be structurally significant

in that it is critical to the structural integrity of the airplane. Tension tie cracking not detected prior to it reaching

critical crack length may result in in-flight depressurization of the airplane and the inability to withstand current

regulatory failsafe loads.

Therefore, a flight-safety inspection program which will continue throughout the operational life of the airplane

is defined in this service bulletin.

The upper deck tension ties have been determined to be structure that is susceptible to Widespread Fatigue

Damage (WFD).

For more information about WFD, refer to Boeing Service Letter 747-SL-53-088.

Boeing Fleet Team Digest (FTD) 747 FTD 53-03005 is related to this service bulletin.

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

7 of 62
Boeing Service Related Problem (SRP) 747-SRP-53-0403 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

AD Related Yes Paragraph 1.E., Compliance

Weight and Balance Change Yes Paragraph 1.H., Weight and Balance Changes

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

Publications Affected Yes 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 85901-120RS)

This bulletin contains a flight safety inspection, an economics based inspection, and a modification. The flight

safety inspection is the minimum inspection program to maintain the structural integrity of the affected area of

the airplane. The economics based inspection, applicable to airplanes on which the modification described

herein has not been incorporated, may be used in lieu of the flight safety inspection, at operator's option, until

the modification is incorporated. The modification described herein will improve the resistance to cracking of

the tension tie but does not alter the structural environment of the tension tie such that a flight safety inspection

is not required. It does enable the initiation of the flight safety inspection to be deferred and increases the

reinspection interval.

Flight Safety Inspection Program - Do a detailed inspection and a surface High Frequency Eddy Current (HFEC)

inspection for cracking in the outboard ends of each affected tension tie. If any cracking is found within specified

limits, do the modification. If any cracking is found out of specified limits, contact Boeing for repair instructions

and do the work instructed by Boeing. If no cracking is found, repeat the inspections until the tension tie is

repaired or modified.

Do the tension tie modification at the time in accordance with Paragraph 1.E., Compliance. The modification

consists of replacing the existing tension tie doubler with a longer doubler.

At tension tie locations that have been repaired or modified, do a detailed inspection for any cracking. If any

cracking is found in a repaired or modified tension tie, contact Boeing for repair instructions and do the work

instructed by Boeing. If no cracking is found, repeat the inspections at the times in accordance with Paragraph

1.E., Compliance.

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

8 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
Economic Inspection Program - The economics based inspections (detailed and surface HFEC inspections at

operator's option) are used to detect cracking at an earlier stage. If any cracking is found within specified limits

do the modification. If cracking is found out of specified limits, contact Boeing for repair instructions and do the

work instructed by Boeing. If no cracking is found, repeat the inspections until the tension tie is repaired or

modified.

EFFECTIVITY

747-100, 747-200B, 747-200F Airplane(s). Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplane(s).

COMPLIANCE

Refer to Paragraph 1.E., Compliance.

Federal Aviation Administration (FAA) Airworthiness Directive AD 84-19-01 is related to this service bulletin.

INDUSTRY SUPPORT INFORMATION

This service bulletin was first released before October of 1994. Thus industry support for affected airplanes

depends upon whether the operator previously filed a warranty claim with Boeing on this service bulletin.

MANPOWER

Airplanes Total Task Hours Elapsed Hours

Inspection 5.00 2.50

Modification 32.00 16.00

MATERIAL INFORMATION

Boeing Supplied Kits/Parts.

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

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

9 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

10 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

11 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

12 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT

BLANK PAGE
Commercial 

Airplanes 747

Service Bulletin

ALERT

Number: 747-53A2088

Original Issue: March 08, 1974

Revision 4: January 11, 2013

ATA System: 5300

SUBJECT: FUSELAGE - Body Station 760 or 780 - Frame to Tension Tie Joint - Inspection /

Modification

THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH

1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO

THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO

THE NEW OWNER.

1. PLANNING INFORMATION

A. Effectivity

1. Airplanes

This service bulletin is for the airplane(s) shown below. Refer to PRR85901-120RS for data about

this change.

Refer to Service Bulletin Index D6-30300 Part 3 for Airplane Variable Number, Line Number, and

Serial Number data.

NOTE:

Airplanes that follow that have been modified by Boeing to the Special Freighter

configuration are not affected by this service bulletin.

1.

2. Airplanes that follow that have been modified by Boeing to the Extended Upper

Deck configuration are not affected by this service bulletin.

3. Airplanes that follow that have been modified as shown in Boeing Service Bulletin

747-25-2692, "Equipment/Furnishings - Upper Deck Passenger Compartment

Conversion - Upper Deck Extension Station 710 - Station 780 Modification," are

not affected by this service bulletin.

GROUP CONFIGURATION DESCRIPTION

747-100 and 747-200B Passenger airplanes with a different Tension

tie lay out to Group 2 and Group 3 airplanes.

1 -

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

13 of 62
GROUP CONFIGURATION DESCRIPTION

747-100 and 747-200B Passenger airplanes with a different Tension

tie lay out to Group 1 and Group 3 airplanes.

2 -

747-200F airplanes with a different Tension tie lay out to Group 1

and Group 2 airplanes.

3 -

Airplane Models:

747-100, 747-200B, 747-200F

Variable Number Group

RA001 - RA025 1

RA027 - RA028 1

RA030 - RA032 1

RA034 1

RA104 - RA110 1

RA113 - RA115 1

RA164 2

RA201 - RA203 1

RA216 1

RA217 2

RA251 - RA255 1

RA256 - RA261 2

RA309 2

RA311 2

RA351 - RA360 1

RA369 - RA371 1

RA372 - RA373 2

RA404 1

RA413 2

RA501 - RA502 1

RA521 - RA523 1

RA525 - RA527 2

RA532 - RA534 1

RA535 - RA540 2

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

14 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
Variable Number Group

RA551 - RA552 1

RA559 - RA560 1

RA561 2

RA581 - RA582 1

RA585 2

RA601 - RA602 1

RA631 1

RA633 1

RA651 - RA652 1

RA676 2

RA701 1

RA702 2

RA721 1

RA741 1

RA761 1

RA781 1

RA903 - RA909 1

RA914 1

RB071 - RB075 2

RB101 - RB102 1

RR201 3

2. Spares Affected

None.

B. Concurrent Requirements

None.

C. Reason

Accomplishment of the inspection program detailed in this bulletin will make sure the structural integrity

of the Body Station 760 or 780 (as applicable) tension tie throughout the operational life of the airplane.

Undetected tension tie cracking could eventually result in in-flight depressurization of the airplane and

the inability to withstand current regulatory failsafe loads.

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

15 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
Body tension ties are located in the upper body just aft of the upper deck floor structure to reduce body

flexure caused by pressurization cycles. On the fatigue test airplane, the tension tie at BS 760 was

found cracked after the equivalent of 12,000 flights. Cracking occurred near the inboard end of the

splice doubler at the juncture of the tension tie and the BS 760 frame. Cracking is attributed to bending

loads induced by frame flexure during cabin pressurization.

Structural reassessment of the 747 airplane has been conducted under the requirements of Federal

Aviation Administration (FAA) Advisory Circular 91-56, in accordance with Federal Aviation Regulation

(FAR) 25.571 as amended in 1978, to ensure the safe operation of 747 airplanes throughout their

operational life. As a result of this reassessment, the affected tension tie has been determined to be

structurally significant in that it is critical to the structural integrity of the airplane. Tension tie cracking

not detected prior to it reaching critical crack length may result in in-flight depressurization of the

airplane.

Therefore, a flight-safety inspection program which will continue throughout the operational life of the

airplane is defined in this service bulletin.

Revision 1 added previously omitted airplanes to Group 1 of the effectivity and incorporated Notice of

Status Change dated 5 April, 1974 which corrected a typographical error in the note under Paragraph

I .A.1.

Revision 2 added the flight safety and economics based inspection program definitions, where applicable,

throughout the service bulletin. In addition, a flight safety addendum is added to the bulletin as a

summary of the inspections required to ensure the structural integrity of the applicable area and to

provide the format for reporting inspection results to Boeing. Notices of Status Change dated 16 October,

1975 and 4 April, 1980 are incorporated to revise subkit nomenclature and to note that airplanes

converted to the Special Freighter configuration are not affected by this bulletin. Also, the effectivity is

updated to reflect current airplane ownership.

Revision 3 is sent to add an alternative tension tie modification. This is shown in new Figures 7, 8, and

9. Revision 3 is also sent to add reference to Boeing Service Bulletin 747-25-2692,

"Equipment/Furnishings - Upper Deck Passenger Compartment Conversion - Upper Deck Extension

Station 710 - Station 780 Modification." As part of the change in Service Bulletin 747-25-2692, the

tension tie at STA 760 is removed and replaced with a floor beam. The work shown in this service

bulletin is not necessary after the change in Service Bulletin 747-25-2692 has been installed. The

airplanes that follow have been removed from Paragraph I.A.1, Effectivity. These airplanes were

changed by Boeing to the Special Freighter or Extended Upper Deck configuration:

RA029, RA033, RA101-RA103, RA111-RA112, RA161-RA163, RA245-RA246, RA301-RA306,

RA307-RA308, RA310, RA312, RA524, RA632, RA634-RA635, RA671-RA675, RA677, RA722-RA724,

RA742-RA743, RA901-RA902, RA910-RA913, RA915-RA916, RB041, RB043.

As part of the change to the Special Freighter or Extended Upper Deck configuration, the tension tie

at STA 760 was removed and replaced with a floor beam. Airplane RB013 has also been removed

from Paragraph I.A.1, Effectivity. On this airplane, a floor beam was installed at BS 760 in production.

All affected airplanes, unmodified or modified per previous issues of this bulletin require flight safety

inspection as noted herein.

The upper deck tension ties have been determined to be structure that is susceptible to Widespread

Fatigue Damage (WFD).

For more information about WFD, refer to Boeing Service Letter 747-SL-53-088.

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

16 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
Boeing Fleet Team Digest (FTD) 747 FTD 53-03005 is related to this service bulletin.

Boeing Service Related Problem (SRP) 747-SRP-53-0403 is related to this service bulletin.

Revision 4 is sent to add a surface High Frequency Eddy Current (HFEC) inspection of the upper and

lower radius common to the aft channel of the tension tie and to add a compliance time for the

accomplishment of the tension tie modification.

D. Description

This bulletin contains a flight safety inspection, an economics based inspection, and a modification.

The flight safety inspection is the minimum inspection program to maintain the structural integrity of

the affected area of the airplane. The economics based inspection, applicable to airplanes on which

the modification described herein has not been incorporated, may be used in lieu of the flight safety

inspection, at operator's option, until the modification is incorporated. The modification described herein

will improve the resistance to cracking of the tension tie but does not alter the structural environment

of the tension tie such that a flight safety inspection is not required. It does enable the initiation of the

flight safety inspection to be deferred and increases the reinspection interval.

Flight Safety Inspection Program - Do a detailed inspection and a surface High Frequency Eddy Current

(HFEC) inspection for cracking in the outboard ends of each affected tension tie. If any cracking is

found within specified limits, do the modification. If any cracking is found out of specified limits, contact

Boeing for repair instructions and do the work instructed by Boeing. If no cracking is found, repeat the

inspections until the tension tie is repaired or modified.

Do the tension tie modification at the time in accordance with Paragraph 1.E., Compliance. The

modification consists of replacing the existing tension tie doubler with a longer doubler.

At tension tie locations that have been repaired or modified, do a detailed inspection for any cracking.

If any cracking is found in a repaired or modified tension tie, contact Boeing for repair instructions and

do the work instructed by Boeing. If no cracking is found, repeat the inspections at the times in

accordance with Paragraph 1.E., Compliance.

Economic Inspection Program - The economics based inspections (detailed and surface HFEC

inspections at operator's option) are used to detect cracking at an earlier stage. If any cracking is found

within specified limits do the modification. If cracking is found out of specified limits, contact Boeing for

repair instructions and do the work instructed by Boeing. If no cracking is found, repeat the inspections

until the tension tie is repaired or modified.

Revision 3 - No more work is necessary on airplanes changed by the initial release, Revision 1, or

Revision 2 of this service bulletin as a result of Revision 3.

The effectivity is divided into three groups because of differences in inspection and modification area.

PLEASE REPORT ADVERSE INSPECTION RESULTS TO BOEING USING THE REPORT SYSTEM

DESCRIBED IN APPENDIX A OF THIS SERVICE BULLETIN.

NOTE: Contact Boeing for instructions if any damaged areas exceed the specified limits. To expedite

Boeing response, be specific when defining and locating the damage. Circumstances leading

up to the damage and any secondary effects, when known, should be included in the

communication and followed up by sketches and photographs when appropriate.

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

17 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
SEND TO: BOEING COMMERCIAL AIRPLANE GROUP ATTENTION: MANAGER, AIRLINE

SUPPORT

Revision 4 - More work is necessary on all airplanes that have not been modified in accordance with

the original issue, Revision 1, Revision 2 or Revision 3 of this service bulletin. Do a surface High

Frequency Eddy Current (HFEC) inspection of the radius common to the aft channel of the tension tie

at the next inspection that is scheduled to be done in accordance with Paragraph 1.E., Compliance

and accomplish the tension tie modification at the time given in Paragraph 1.E., Compliance.

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

Group 1-2:

Affected Maintenance Zones

Model Zone

747-100, 747-200B 233, 234

Group 3:

Affected Maintenance Zones

Model Zone

747-200F 233, 234

E. Compliance

Federal Aviation Administration (FAA) Airworthiness Directive AD 84-19-01 is related to this service

bulletin.

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

18 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
Table 1: Tension Tie Inspection and Modification (Flight Safety Inspection Program)

Repeat Interval

(Not to Exceed)

Compliance Time (Whichever

Occurs Later)

Condition Action

3,700 flight cycles.(a)Within 500 flight

cycles after the

effective date of

AD 84-19-01.

Before 8,000 total flight cycles.Do a detailed inspection

of the tension tie at BS

760 (Group 1 and 2 airplanes) or BS 780 (Group

3 airplanes) for any

cracking in accordance

with Paragraph 3.B.,

Work Instructions Part I.

Airplanes that have not accomplished the modification to the tension tie at BS

760 (Group 1 and 2) or BS

780 (Group 3) in accordance with this service bulletin.

Within 3,700

flight cycles after the Revision

4 date of this

service bulletin.

Before 8,000 total flight cycles.Do a detailed inspection

and a surface High Frequency Eddy Current

(HFEC) inspection of the

tension tie at BS 760

(Group 1 and 2 airplanes)

or BS 780 (Group 3 airplanes) for any cracking

in accordance with Paragraph 3.B., Work Instructions Part I.

Do the modification in ac- Before further flight. -

cordance with Paragraph

3.B., Work Instructions

Part III.

If cracking is found within

limits.

(a)

Contact Boeing for repair Before further flight. -

instructions and do the

work instructed by Boeing.

If cracking is found in the

tension tie out of limits.

Within 2,000 -

flight cycles after the Revision

4 date of this

service bulletin.

Before 16,000

total flight cycles.

Do the modification in accordance with Paragraph

3.B., Work Instructions

Part III.

(a)

If no cracking is found.

(a) Accomplishment of the modification terminates the repeat inspection requirement. Refer to Table 2 for

post modification inspections.

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

19 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
Table 2: Post Modification Inspection (Flight Safety Inspection Program)

Repeat Interval

(Not to Exceed)

Compliance Time (Whichever

Occurs Later)

Condition Action

8,000 flight cycles.

(a)

Within 1,000

flight cycles after the effective

date of AD 84-

19-01. (a)

Within 10,000

flight cycles after the accomplishment of the

modification. (a)

Do a detailed inspection

of the tension tie at BS

760 (Group 1 and 2 airplanes) or BS 780 (Group

3 airplanes) for any

cracking in accordance

with Paragraph 3.B.,

Work Instructions Part I.

Airplanes that have accomplished the Modification to

the tension tie at BS 760

(Group 1 and 2 airplanes)

or BS 780 (Group 3 airplanes) in accordance with

this service bulletin.

Contact Boeing for repair Before further flight. -

instructions and do the

work instructed by Boeing.

If any crack is found in a

modified tension tie.

(a) Additional post modification inspections are given in Boeing service bulletin 747-53A2502.

Table 3: Tension Tie Inspection and Modification (Economic Based Inspection Program)

Repeat Interval

(Not to Exceed)

Compliance Time (Whichever

Occurs Later)

Condition Action

1,000 flight cycles.(a)Do a detailed inspection Before 7,000 total flight cycles.

and a surface High Frequency Eddy Current

(HFEC) inspection of the

tension tie at BS 760

(Group 1 and 2 airplanes)

or BS 780 (Group 3 airplanes) for any cracking

in accordance with Paragraph 3.B., Work Instructions Part II.

Airplanes that have not accomplished the modification to the tension tie at BS

760 (Group 1 and 2) or BS

780 (Group 3) in accordance with this service bulletin.

Do the modification in ac- Before further flight. -

cordance with Paragraph

3.B., Work Instructions

Part III.

If cracking is found within

limits.

(a)

Contact Boeing for repair Before further flight. -

instructions and do the

work instructed by Boeing.

If cracking is found in the

tension tie out of limits.

Within 2,000 -

flight cycles after the Revision

4 date of this

service bulletin.

Before 16,000

total flight cycles.

Do the modification in accordance with Paragraph

3.B., Work Instructions

Part III.

(a)

If no cracking is found.

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

20 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
Table 3: Tension Tie Inspection and Modification (Economic Based Inspection Program)

Repeat Interval

(Not to Exceed)

Compliance Time (Whichever

Occurs Later)

Condition Action

(a) Accomplishment of the modification terminates the repeat inspection requirement. Refer to Table 2 for

post modification inspections.

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.

In addition, the Manager of the FAA Seattle Aircraft Certification Office (ACO) approves the

accomplishment of the inspection, modification and post modification inspections with the corresponding

compliance times given in Service Bulletin 747-53A2088, Revision 4, as an alternative method of

compliance to the inspection, optional modification, and post modification inspection requirements with

corresponding compliance times required by paragraphs (A) and (B) of AD 84-19-01. Where this SB

states to contact Boeing for repair instructions, these instructions must be approved as an AMOC per

the instructions in paragraph (C) of AD 84-19-01. All provisions of AD 84-19-01 that are not specifically

referenced in this paragraph 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 inspection and modification

for each airplane. This estimate is for direct labor only, done by an experienced crew. Adjust the estimate

with operator task hour data if necessary. The estimate does not include lost time. These are some

examples of lost time:

• Time to adjust to the workplace

• Time to schedule the work

• Time to inspect the work

• Time to cure the materials

• Time to make the parts

• Time to find the tools.

Task Number of Persons Task Hours Elapsed Hours

Open Access 2 1.00 0.50

Inspection 2 3.00 1.50

Repair (a) (a) (a)

Modification 2 30.00 15.00

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

21 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
Task Number of Persons Task Hours Elapsed Hours

Restoration 2 1.00 0.50

TOTAL FOR EACH AIRPLANE

Inspection 3.00 1.50

Repair (a) (a)

Modification 32 16

(a) For some tension tie cracks, the modification can be used as a repair. For

unmodified airplanes with cracks other than as described in Paragraph 3.B.,

Work Instructions, repair time will depend on extent of cracking.

H. Weight and Balance Changes

Group 1-2:

Change in Moment

(Pound-Inches)

Change in Weight

Airplane (Pounds)

Tension Tie Modification + 0.8 + 585.2

Alternative Modification + 0.5 + 390.7

Group 3:

Change in Moment

(Pound-Inches)

Change in Weight

Airplane (Pounds)

Tension Tie Modification + 0.8 + 627.8

Alternative Modification + 0.5 + 401.0

I. Electrical Load Data

Not applicable.

J. References

1. Existing Data:

a. Engineering Change Memo PRR 85901-120RS

b. Boeing Service Bulletin 747-25-2692, 747-53A2502

c. Boeing Service Letter 747-SL-51-048, 747-SL-53-088

d. Boeing Service Related Problem (SRP) 747-SRP-53-0403

e. Federal Aviation Administration (FAA) Airworthiness Directive (AD) 84-19-01

f. Service Bulletin Index D6-30300

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

22 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
g. 747 Fleet Team Digest (FTD) 53-03005

h. 747 Non-Destructive Testing (NDT) Manual Part 6, 51-00-00 Procedure 1, Procedure 4,

Procedure 11, Procedure 16, Procedure 23

i. 747-100/200/300 Aircraft Maintenance Manual (AMM) 25-22-01

2. Data Supplied with this Service Bulletin:

None.

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

Drawing Number Title

65B09631 Tension Tie Installation - STA 760 to STA 940

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

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

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

K. Publications Affected

1. Publications:

Publication Chapter-Section

747 Structural Repair Manual 53-10

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.

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

23 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

24 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT

BLANK PAGE
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 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 03

date of this Service Bulletin (US

Dollars)

ROLT as of the

Revision 03 date

of this Service

Bulletin (Calendar

Days)

Kit Number Name

KIT, FRAME TO TENSION TIE JOINT 280 $672.00

MODIFICATION - BODY STATION 760

63B12132-1

B. Industry Support Information

This service bulletin was first released before October of 1994. Thus industry support for affected

airplanes depends upon whether the operator previously filed a warranty claim with Boeing on 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: Top kit assembly is divided into subkits for convenience of installation. One top kit and

the items shown in Paragraph 2.C.2., Parts and Materials Supplied by the Operator, are

necessary for each airplane.

63B12132 - FRAME TO TENSION TIE JOINT MODIFICATION - BODY STATION 760

Kit 63B12132-1

New Part Number QTY Name

-3 -2 -1

63B12132-1 . . - Top Kit Assembly

63B12132-2 . - 1 Kit Assembly, Left Side

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

25 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
63B12132 - FRAME TO TENSION TIE JOINT MODIFICATION - BODY STATION 760

Kit 63B12132-1

New Part Number QTY Name

-3 -2 -1

63B12132-3 - . 1 Kit Assembly, Right Side

65B42544-1 . 1 . Doubler

65B42544-2 1 . . Doubler

BACB30KK6-3 6 6 . Bolt

BACB30KK6-4 12 12 . Bolt

BACB30KK6-5 15 15 . Bolt

BACB30KK8-6 3 3 . Bolt

BACB30KK8-7 5 5 . Bolt

BACB30KK8-8 5 5 . Bolt

BACC30R6 33 33 . Collar

BACC30R8 13 13 . Collar

BACR15BA6D10 2 2 . Rivet

2. Parts and Materials Supplied by the Operator

NOTE: The parts and materials shown in the table that follows are necessary to install the

alternative modification shown in Figures 7, 8, or 9.

Group 1 Name Notes

QTY

Group 2

QTY

Group 3

QTY

Part Number /

Specification

A . . 2 Strap (a)

B . 2 . Strap (b)

C 2 . . Strap (c)

BACB30MY6K4X 4 1 1 Bolt (e)

BACB30MY6K5X 3 6 6 Bolt (e)

BACB30MY6K6X . 1 1 Bolt (e)

BACB30MY6K7X . 2 3 Bolt (e)

BACB30MY6K8X 5 . . Bolt (e)

BACB30MY6K9X 5 . . Bolt (e)

BACB30MY6K4Y 8 6 6 Bolt (e)

BACB30MY8K4 2 2 2 Bolt (e)

BACB30MY8K7X . . 1 Bolt (e)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

26 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
Group 1 Name Notes

QTY

Group 2

QTY

Group 3

QTY

Part Number /

Specification

BACB30MY8K8X . 3 5 Bolt (e)

BACB30MY8K9X . 3 . Bolt (e)

BACC30M6 15 9 10 Collar -

BACC30M8 2 8 8 Collar -

BACC30R6 8 6 6 Collar -

BMS 5-95 4 Ounces 4 Ounces 4 Ounces Sealant (d)

BMS 10-11, Type I 4 Ounces 4 Ounces 4 Ounces Paint -

(a) Make as shown in FIGURE 7.

(b) Make as shown in FIGURE 8.

(c) Make as shown in FIGURE 9.

(d) Refer to the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier data.

(e) Refer to 747 Structural Repair Manual Chapter 51 for alternate fasteners.

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.

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

27 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

28 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT

BLANK PAGE
3. ACCOMPLISHMENT INSTRUCTIONS

A. GENERAL INFORMATION

CAUTION: KEEP THE WORK AREA, WIRES AND ELECTRICAL BUNDLES CLEAN OF METAL

PARTICLES OR CONTAMINATION WHEN YOU USE TOOLS. UNWANTED MATERIAL,

METAL PARTICLES OR CONTAMINATION CAUGHT IN WIRE BUNDLES CAN CAUSE

DAMAGE TO THE BUNDLES. DAMAGED WIRE BUNDLES CAN CAUSE SPARKS OR

OTHER ELECTRICAL DAMAGE.

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

definition of the acronyms.

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

3. Unless shown differently, these dimensions and tolerances are used:

– Linear dimensions are in inches

– Tolerance on linear dimensions, other than rivet and bolt edge margins, is plus

or minus 0.03 inch

– Tolerance on rivet and bolt edge margin is plus or minus 0.05 inch

– Angular tolerance is plus or minus 2 degrees

– Hole dimensions for standard solid rivets and fasteners are in Structural Repair

Manual (SRM) Chapter 51

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. 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.

8. Boeing Service Letter 747-SL-51-048 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.

9. Refer to Appendix A for Addendum on flight safety.

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

29 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
10. The instructions in Paragraph 3.B., Work Instructions and the figures can include

operation of tools or test equipment. Boeing Engineering Tool Drawings, the Illustrated

Tool and Equipment Manual, and the Special Tool and Ground Handling Drawing

Index contain data on versions of the tools or test equipment that you can use. It is

permitted to use replaced tools. It is not permitted to use superseded tools.

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.

B. WORK INSTRUCTIONS

PART I - FLIGHT SAFETY INSPECTION PROGRAM

1. On airplanes on which Part III - Modification has not been incorporated accomplish the following:

a. Do a detailed inspection and a surface High Frequency Eddy Current (HFEC) inspection of

the tension tie at BS 760 (Group 1 and 2 airplanes) or BS 780 (Group 3 airplanes) for any

cracking in accordance with FIGURE 1.

b. If no cracking is found, repeat the tension tie inspections in accordance with FIGURE 1 at the

time given in Paragraph 1.E., Compliance or alternatively, accomplish Part III - Modification

and do the tension tie inspection in accordance with Part I, Step 2.

c. If any cracking is found in one channel of the tension tie at the most inboard row of fasteners

common to the tension tie channels and the existing steel joint doubler or in the aft channel

in the area of the channel trim out, do the Part III - Modification as a repair and do the

inspections in accordance with Part I, Step 2. If any cracking is found other than as described

above, contact Boeing for repair instructions and do the work instructed by Boeing.

d. Restore access and return the airplane to a serviceable condition.

2. On airplanes on which Part III - Modification has been incorporated accomplish the following:

a. Do a detailed inspection of the tension tie at BS 760 (Group 1 and 2 airplanes) or BS 780

(Group 3 airplanes) for any cracking in accordance with FIGURE 2 at the time given in

Paragraph 1.E., Compliance.

b. If no cracking is found, repeat the inspections in accordance with FIGURE 2 at the time given

in Paragraph 1.E., Compliance.

c. If any cracking is found, contact Boeing for repair instructions and do the work instructed by

Boeing.

d. Restore access and return the airplane to a serviceable condition.

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

30 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
PART II - ECONOMICS BASED INSPECTION PROGRAM - OPERATOR'S OPTION

1. Do a detailed inspection and a surface High Frequency Eddy Current (HFEC) inspection of the

tension tie at BS 760 (Group 1 and 2 airplanes) or BS 780 (Group 3 airplanes) for any cracking in

accordance with FIGURE 1.

NOTE:

1. This inspection may be used in lieu of Part I - Flight Safety Inspection Program,

at operator's option, until Part III - Modification is accomplished.

2. This inspection applies only to airplanes on which Part III - Modification has not

been accomplished.

2. If no cracking is found, repeat the tension tie inspection in accordance with FIGURE 1 at the time

given in Paragraph 1.E., Compliance or alternatively, do the modification in accordance with Part

III - Modification and do tension tie modification inspections in accordance with Part I, Step 2.

3. If any cracking is found in one channel of the tension tie at the most inboard row of fasteners

common to the tension tie channels and the existing steel joint doubler or in the aft channel in the

area of the channel trim out, do the Part III - Modification as a repair and initiate re-inspections in

accordance with Part I, Step 2. If any cracking is found other than as described above, contact

Boeing for repair instructions and do the work instructed by Boeing.

4. Restore access and return the airplane to a serviceable condition.

PART III - MODIFICATION

1. Get access to the tension tie ends at BS 760 (Group 1 and 2 airplanes) or BS 780 (Group 3

airplanes) by removing ceiling panels 231HL and 231HR (if installed). Refer to 747-100/200/300

AMM 25-22-01 or operator's comparable procedure.

NOTE: This modification may be used as an alternative to repeat inspections in accordance with

Part II, as a means of deferring initial or repeat inspections in accordance with Part I, or

as a repair for cracks as shown in the notes that follow. The modification does not terminate

Part I inspection requirements.

2. Replace existing tension tie end doublers with longer doublers in accordance with FIGURE 3. As

an alternative, modify the tension tie in accordance with FIGURE 7, FIGURE 8 or FIGURE 9.

NOTE:

1. The modification in accordance with FIGURE 3 may be used as a repair for a

crack in one channel of the tension tie at the most inboard row of fasteners

common to the tension tie channels and the existing steel joint doubler on

unmodified airplanes.

2. The modification in accordance with FIGURE 7, FIGURE 8 or FIGURE 9 can

also be used as a repair for cracks in the aft channel of the tension tie. This

repair can only be used if the trim in accordance with FIGURE 7, FIGURE 8 or

FIGURE 9 completely removes all cracks in the aft channel. If the trim does not

completely remove all cracks from the aft channel, or if other cracks are found,

contact Boeing for repair instructions and do the work instructed by Boeing.

3. Reinstall access panels and return the airplane to a serviceable condition.

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

31 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
4. Do inspections of the modified tension ties in accordance with Part I. Step 2, at the times given in

Paragraph 1.E., Compliance.

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4: January 11, 2013 747-53A2088

32 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
FIGURE 1: UNMODIFIED TENSION TIE INSPECTION

(SHEET 1 OF 3)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

33 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
FIGURE 1: UNMODIFIED TENSION TIE INSPECTION

(SHEET 2 OF 3)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

34 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
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 Remove / Keep Ceiling Panels - - (a)

2 Inspect Tension Tie - - (b)

3 Inspect Tension Tie - - (c) (d)

4 Inspect Tension Tie - - (c) (d)

(a) Get access to the tension tie ends at BS 760 (Group 1 and 2 airplanes) or BS 780 (Group 3 airplanes)

by removing ceiling panels 231HL and 231HR (if installed). Refer to 747-100/200/300 AMM 25-22-01 or

operator's comparable procedure.

(b) Do a detailed inspection of the indicated tension tie area on the left and right side for any cracking.

(c) Do a detailed inspection of the edge of the radius of the tension tie aft channel on the left and right side

for any cracking.

(d) Do a surface High Frequency Eddy Current (HFEC) inspection on the edge of the radius of the tension

tie aft channel on the left and right side for any cracking. Do the inspection in accordance with 747 NDT

Part 6, 51-00-00, Procedure 4 or Procedure 23.

FIGURE 1: UNMODIFIED TENSION TIE INSPECTION

(SHEET 3 OF 3)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

35 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
FIGURE 2: MODIFIED TENSION TIE INSPECTION

(SHEET 1 OF 2)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

36 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
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 Remove / Keep Ceiling Panels - - (a)

2 Inspect Tension Tie - - (b)

(a) Get access to the tension tie ends at BS 760 (Group 1 and 2 airplanes) or BS 780 (Group 3 airplanes)

by removing ceiling panels 231HL and 231HR (if installed). Refer to 747-100/200/300 AMM 25-22-01 or

operator's comparable procedure.

(b) Do a detailed inspection of the indicated tension tie area on the left and right side for any cracking.

FIGURE 2: MODIFIED TENSION TIE INSPECTION

(SHEET 2 OF 2)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

37 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
FIGURE 3: FRAME TENSION TIE MODIFICATION

(SHEET 1 OF 5)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

38 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
FIGURE 3: FRAME TENSION TIE MODIFICATION

(SHEET 2 OF 5)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

39 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
FIGURE 3: FRAME TENSION TIE MODIFICATION

(SHEET 3 OF 5)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

40 of 62

BOEING SERVICE BULLETIN 747-53A2088

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

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

Step Task Name Identification Qty More Data

1 Remove Fasteners - 40 Group 1.

Remove Fasteners - 39 Group 2 and 3.

65B09614-27 - -

(65B09614-19 or

65B09614-21 optional)

2 Remove Doubler

3 Countersink Hole - 2 Group 2 only.

4 Install (New) Doubler 65B42544-1 1 Left side.

Install (New) Doubler 65B42544-2 1 Right side.

The codes shown below agree with the letter shown in the upper left corner of the fastener symbols in the figure.

A number in the lower right corner gives the grip length of the fastener. The QTY numbers shown below are the

number of fasteners necessary for this figure.

Code Name Identification Qty Hole Dia More Data

Install with BMS 5-95

sealant.

A Bolt BACB30KK6-( ) - 0.216 - 0.219

Collar BACC30R6 - - -

Install with BMS 5-95

sealant

B Bolt BACB30KK8-( ) - 0.278 - 0.281

Collar BACC30R8 - - -

FIGURE 3: FRAME TENSION TIE MODIFICATION

(SHEET 4 OF 5)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

41 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
Code Name Identification Qty Hole Dia More Data

100 degree countersink

0.33 inch diameter forward side only.

C Rivet BACR15BA6D10 - -

FIGURE 3: FRAME TENSION TIE MODIFICATION

(SHEET 5 OF 5)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

42 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
FIGURE 4: THIS FIGURE IS DELETED (REVISION 4)

(SHEET 1 OF 1)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

43 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
FIGURE 5: THIS FIGURE IS DELETED (REVISION 4)

(SHEET 1 OF 1)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

44 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
FIGURE 6: THIS FIGURE IS DELETED (REVISION 4)

(SHEET 1 OF 1)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

45 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
This Figure applies only to: Group 1.

FIGURE 7: ALTERNATIVE MODIFICATION

(SHEET 1 OF 5)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

46 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
FIGURE 7: ALTERNATIVE MODIFICATION

(SHEET 2 OF 5)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

47 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
FIGURE 7: ALTERNATIVE MODIFICATION

(SHEET 3 OF 5)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

48 of 62

BOEING SERVICE BULLETIN 747-53A2088

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

numbers shown below are the number of parts necessary for one side of the airplane.

NOTE:

The figure shows two alternate aft channel trims. Any trim line that is between those shown

in the figure is acceptable. At least five fasteners in each row are necessary common to the

aft channel, forward channel and repair strap inboard of the trim line.

1.

2. Install all parts with BMS 5-95 sealant.

3. All trimmed edges and repair parts should be finished to 125 microinches or better.

Step Task Name Identification Qty More Data

1 Remove Fasteners - - -

2 Remove / Keep Plate - 1 -

3 Cut Aft Channel - 1 -

4 Remove Trimmed Section - 1 -

To aft channel to

match adjacent

structure.

5 Apply Paint - -

6 Make Repair Strap A 1 0.071 thick 2024-T3.

One coat BMS 10-

11, Type I.

Apply Paint - -

Install (New) Repair Strap A 1 Trim as necessary.

7 Install (Kept) Plate - 1 -

FIGURE 7: ALTERNATIVE MODIFICATION

(SHEET 4 OF 5)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

49 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
The codes shown below agree with the letter shown in the upper left corner of the fastener symbols in the figure.

A number in the lower right corner gives the grip length of the fastener. The QTY numbers shown below are the

number of fasteners necessary for this figure.

Code Name Identification Qty Hole Dia More Data

Install with BMS 5-95

sealant.

0.2026 -

0.2036

D Bolt BACB30MY6K( )X -

Collar BACC30M6 - - -

Install with BMS 5-95

sealant.

0.2651 -

0.2661

E Bolt BACB30MY8K( )X -

Collar BACC30M8 - - -

Install with BMS 5-95

sealant.

F Bolt BACB30MY6K4Y - 0.216 - 0.219

Collar BACC30R6 - - -

Install with BMS 5-95

sealant.

0.2495 -

0.2505 (a)

G Bolt BACB30MY8K4 -

Collar BACC30M8 - - -

(a) Before the hole is made larger, do an open hole HFEC inspection at these locations in accordance with

747 NDT Part 6, 51-00-00, Procedure 1 or Procedure 11 or Procedure 16. If no cracking is found, make

the fastener holes the size shown.

FIGURE 7: ALTERNATIVE MODIFICATION

(SHEET 5 OF 5)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

50 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
This Figure applies only to: Group 2.

FIGURE 8: ALTERNATIVE MODIFICATION

(SHEET 1 OF 5)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

51 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
FIGURE 8: ALTERNATIVE MODIFICATION

(SHEET 2 OF 5)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

52 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
FIGURE 8: ALTERNATIVE MODIFICATION

(SHEET 3 OF 5)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

53 of 62

BOEING SERVICE BULLETIN 747-53A2088

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

numbers shown below are the number of parts necessary for one side of the airplane.

NOTE:

The figure shows two alternate aft channel trims. Any trim line that is between those shown

in the figure is acceptable. At least five fasteners in each row are necessary common to the

aft channel, forward channel and repair strap inboard of the trim line.

1.

2. Install all parts with BMS 5-95 sealant.

3. All trimmed edges and repair parts should be finished to 125 microinches or better.

Step Task Name Identification Qty More Data

1 Remove Fasteners - - -

2 Remove / Keep Plate - 1 -

3 Cut Aft Channel - 1 -

4 Remove Trimmed Section - 1 -

To aft channel to

match adjacent

structure.

5 Apply Paint - 1

6 Make Repair Strap B 1 0.071 thick 2024-T3.

One coat BMS 10-

11, Type I.

Apply Paint - -

Install (New) Repair Strap B - Trim as necessary

7 Install (Kept) Plate - 1 -

FIGURE 8: ALTERNATIVE MODIFICATION

(SHEET 4 OF 5)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

54 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
The codes shown below agree with the letter shown in the upper left corner of the fastener symbols in the figure.

A number in the lower right corner gives the grip length of the fastener. The QTY numbers shown below are the

number of fasteners necessary for this figure.

Code Name Identification Qty Hole Dia More Data

Install with BMS 5-95

sealant.

0.2026 -

0.2036

D Bolt BACB30MY6K( )X -

Collar BACC30M6 - - -

Install with BMS 5-95

sealant.

0.2651 -

0.2661

E Bolt BACB30MY8K( )X -

Collar BACC30M8 - - -

Install with BMS 5-95

sealant.

F Bolt BACB30MY6K4Y - 0.216 - 0.219

Collar BACC30R6 - - -

Install with BMS 5-95

sealant.

0.2495 -

0.2505 (a)

G Bolt BACB30MY8K4 -

Collar BACC30M8 - - -

(a) Before the hole is made larger, do an open hole HFEC inspection at these locations in accordance with

747 NDT Part 6, 51-00-00, Procedure 1 or Procedure 11 or Procedure 16. If no cracking is found, make

the fastener holes the size shown.

FIGURE 8: ALTERNATIVE MODIFICATION

(SHEET 5 OF 5)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

55 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
This Figure applies only to: Group 3.

FIGURE 9: ALTERNATIVE MODIFICATION

(SHEET 1 OF 5)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

56 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
FIGURE 9: ALTERNATIVE MODIFICATION

(SHEET 2 OF 5)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

57 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
FIGURE 9: ALTERNATIVE MODIFICATION

(SHEET 3 OF 5)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

58 of 62

BOEING SERVICE BULLETIN 747-53A2088

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

numbers shown below are the number of parts necessary for one side of the airplane.

Step Task Name Identification Qty More Data

1 Remove Fasteners - - -

2 Remove / Keep Plate - 1 -

3 Cut Aft Channel - 1 -

4 Remove Trimmed Section - 1 -

To aft channel to

match adjacent

structure.

5 Apply Paint - 1

6 Make Repair Strap C 1 0.071 thick 2024-T3.

One coat BMS 10-

11, Type I.

Apply Paint - 1

Install (New) Repair Strap C - Trim as necessary.

7 Install (Kept) Plate - 1 -

FIGURE 9: ALTERNATIVE MODIFICATION

(SHEET 4 OF 5)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

59 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
The codes shown below agree with the letter shown in the upper left corner of the fastener symbols in the figure.

A number in the lower right corner gives the grip length of the fastener. The QTY numbers shown below are the

number of fasteners necessary for this figure.

Code Name Identification Qty Hole Dia More Data

Install with BMS 5-95

sealant.

0.2026 -

0.2036

D Bolt BACB30MY6K( )X -

Collar BACC30M6 - - -

Install with BMS 5-95

sealant.

0.2651 -

0.2661

E Bolt BACB30MY8K( )X -

Collar BACC30M8 - - -

Install with BMS 5-95

sealant.

F Bolt BACB30MY6K4Y - 0.216 - 0.219

Collar BACC30R6 - - -

Install with BMS 5-95

sealant.

0.2495 -

0.2505 (a)

G Bolt BACB30MY8K4 -

Collar BACC30M8 - - -

(a) Before the hole is made larger, do an open hole HFEC inspection at these locations in accordance with

747 NDT Part 6, 51-00-00, Procedure 1 or Procedure 11 or Procedure 16. If no cracking is found, make

the fastener holes the size shown.

FIGURE 9: ALTERNATIVE MODIFICATION

(SHEET 5 OF 5)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

60 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
APPENDIX A: INSPECTION TO ENSURE STRUCTURAL INTEGRITY OF AIRFRAME

A structural reassessment of the 747 airplane has been conducted under the requirements of Federal Aviation

Administration (FAA) Advisory Circular 91-56, in accordance with Federal Aviation Regulation (FAR) 25.571 as

amended in 1978, to ensure safe operation of 747 airplanes throughout their operational life.

Table I is a summary of the inspections specified in the Accomplishment Instructions, Part 1 - Flight Safety

Inspection Program that are recommended for the detection of cracks in the Body Station (BS) 760 or 780 (as

applicable) tension tie prior to their reaching critical length. Failure to detect cracks prior to their reaching critical

length may result in in-flight depressurization of the airplane and the inability to withstand current regulatory

failsafe loads.

Any cracked tension ties should be repaired prior to further flight unless specifically approved by your cognizant

regulatory agency.

Please report any discrepancies using the reporting system described in this addendum.

TABLE I

Repeat Inspection Interval (Flights)Repeat Inspection

Threshold (Flights)

Airplane Condition Inspection Method

8,000 or within 500 after 3,700

the effective date of AD

84-19-01, whichever occurs later.

Service Bulletin Modifica- Detailed Inspection

tion Not Accomplished

Detailed Inspection and a 8,000 3,700

surface High Frequency

Eddy Current (HFEC) Inspection

(a)

Service Bulletin Modifica- Detailed Inspection 10,000 after Modification 8,000

tion Accomplished (b)

(a) For airplanes over the threshold at receipt of addendum, inspect within 3,700 flights after the Revision 4

date of this service bulletin.

(b) For airplanes over the threshold at receipt of addendum, inspect within 1000 flights after the effective date

of AD 84-19-01.

Boeing requests that operators use the following Structural Significant Item (SSI) Reporting System to report

any discrepancies that are found during accomplishment of a Flight Safety Inspection.

1. Upon recognition of a discrepancy, the following information should be telegraphed to Boeing:

Heading: ATTENTION - SSI DISCREPANCY - SERVICE BULLETIN RELATED

– Service Bulletin Number

– Airplane serial number upon which discrepancy was found

– Identification of structural item found damaged

– Flight-cycles and hours on damaged item

APPENDIX A: ADDENDUM - FLIGHT SAFETY SECTION

(SHEET 1 OF 2)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

61 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT
– Location and description of damage including direction and size

– When discovered and inspection method used.

Send telegram through Boeing Field Service Representative or directly to:

747 Customer Support Engineering

2. An Operator's Follow-up Report containing all available pertinent data relative to the structural

discrepancy shall be sent to Boeing. A summary of the information that should be reported is shown

in the SSI DISCREPANCY REPORT form in the Supplemental Structural Inspection Document (SSID),

Boeing Document D6-35022. Operators may use this form or any suitable alternative which contains

the same information.

3. All data and reports dealing with the Flight Safety Inspection Program shall be submitted either through

a Boeing Field Service Representative or directly to:

Boeing Commercial Airplane Group

P.O. Box 3707

Seattle, Washington 98124

Attn: Director, 747/767 Customer Support Engineering

Org. M-7201, Mail Stop 04-CR

4. All reports will be reviewed immediately.

5. The Boeing Company will summarize the results of all reported significant data for distribution

semiannually to operators and appropriate Airworthiness Authorities.

APPENDIX A: ADDENDUM - FLIGHT SAFETY SECTION

(SHEET 2 OF 2)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: March 08, 1974

Revision 4 January 11, 2013 747-53A2088

62 of 62

BOEING SERVICE BULLETIN 747-53A2088

ALERT ALERT