Commercial 

Airplanes 747

Service Bulletin

ALERT

Number: 747-53A2478

Original Issue: February 07, 2002

Revision 3: October 17, 2011

ATA System: 5361

SUBJECT: FUSELAGE - Section 46 and Section 48 - Vertical Stabilizer Seal - Skin Damage

Protection at Seal Interface - Inspection and Repair

Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15

CFR 730-774). An export license may be required before it is used for development, production or use by foreign

persons from specific countries. The controller of this data has the individual responsibility to abide by all export

laws.

ECCN: 9E991

BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET

Copyright © 2002 The Boeing Company

Unpublished Work - All Rights Reserved

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

subject matter. Boeing also claims copyright in this document as a compilation and/or collective work.

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

Treatment of the document and the information it contains is governed by contract with Boeing. For more

information, contact The Boeing Company, P.O. Box 3707, Seattle, Washington 98124.

Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, Dreamliner,

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 the

Boeing livery 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 PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

1 of 52

2.0
BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

2 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT

BLANK PAGE
Table of Contents

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

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

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

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

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

2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

B. Concurrent Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

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

D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

E. Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

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

G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

H. Weight and Balance Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

1. Existing Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

2. Data supplied with this Service Bulletin: . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

3. Installation Drawings Used in the Preparation of this Service Bulletin: . . . . . . . . . . . 33

K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

2. MATERIAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

A. Material - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

C. Parts Necessary For Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

1. Kits/Parts: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

2. Parts and Materials Supplied by the Operator: . . . . . . . . . . . . . . . . . . . . . . . . 35

3. Parts Modified and Reidentified: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

4. Parts Removed and Not Replaced: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

D. Parts Necessary to Change Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

E. Special Tooling - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

F. Special Tooling Necessary to do this Service Bulletin . . . . . . . . . . . . . . . . . . . . . . . 36

3. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

B. WORK INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

FIGURE 1: LOGIC DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

FIGURE 2: ACCESS / RESTORATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

FIGURE 3: FUSELAGE SKIN INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

FIGURE 4: FUSELAGE SKIN REWORK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

3 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

4 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT

BLANK PAGE
Commercial 

Airplanes 747

Service Bulletin

ALERT

Revision Transmittal Sheet Number: 747-53A2478

Original Issue: February 07, 2002

Revision 3: October 17, 2011

ATA System: 5361

SUBJECT: FUSELAGE - Section 46 and Section 48 - Vertical Stabilizer Seal - Skin Damage

Protection at Seal Interface - Inspection and Repair

This revision includes all pages of the service bulletin.

COMPLIANCE INFORMATION RELATED TO THIS REVISION

More work is necessary on the airplane(s) changed in accordance with Revision 1 or Revision 2 of this service

bulletin. Do repeat inspections in accordance with Revision 3.

Federal Aviation Administration (FAA) Airworthiness Directive AD 2009-14-02 is related to this service bulletin.

REASON FOR REVISION

This revision is sent to change the repeat inspection requirements for all airplanes, to add the requirement for

rub strip installation for airplanes with wear or blend that exceeds Structural Repair Manual limits and to add

the requirement to clean the skin at each inspection interval. Since the release of Revision 2 of this service

bulletin, one operator has reported wear through the fuselage skin between Body Station (STA) 2598 and STA

2638, stringers S-2L to S-3L. The wear developed in less than 3,657 flight hours since the previous inspection,

which was less than the repeat inspection interval given in Revision 2 of the service bulletin. The wear occurred

through both the Teflon filled coating and the full thickness of the 0.050 inch thick skin to create a hole

approximately 16 inches in length.

These sections were changed:

1. Paragraph 1.C., Reason: Revision information is added.

2. Paragraph 1.D., Description: Revision information is added.

3. Paragraph 1.E., Compliance: Conditions, compliance times and repeat inspection intervals are changed.

Requirement for rub strip installation is added. Requirement to clean skin is added.

4. Paragraph 1.F., Approval: Approval information information is updated.

5. Paragraph 1.G., Manpower: Manpower estimates are changed.

6. Paragraph 1.J., References: New references are added to existing data.

7. Paragraph 3.A., General Information: Note allowing sequence of steps to be changed is removed. New

notes are added.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

5 of 52
8. Paragraph 3.B., Work Instructions: Alternative access method is added. HFEC inspection requirement is

clarified. Repair options are clarified. Rub strip installation requirement is added. Instruction to apply Teflon

filled coating is changed. Instruction to clean the skin is added. Optional economic based additional

inspections and procedures are added.

9. Figure 3: HFEC inspection requirement is clarified.

10. Figure 4: Teflon filled coating minimum thickness requirement is added.

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: February 07, 2002

Revision 1: March 27, 2008

Revision 2: July 15, 2010

Revision 3: October 17, 2011

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

6 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
Commercial 

Airplanes 747

Service Bulletin

ALERT

Summary Number: 747-53A2478

Original Issue: February 07, 2002

Revision 3: October 17, 2011

ATA System: 5361

SUBJECT: FUSELAGE - Section 46 and Section 48 - Vertical Stabilizer Seal - Skin Damage

Protection at Seal Interface - Inspection and Repair

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

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

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

THE NEW OWNER.

CONCURRENT REQUIREMENTS

None.

BACKGROUND

Accomplishment of this service bulletin will detect cracks and accelerated skin wear damage from the vertical

stabilizer seal beyond allowable limits. The fuselage skin is subject to wear damage in the area of the vertical

stabilizer seal interface in Section 46 (Section 47 on 747-400 Large Cargo Freighter, LCF) and Section 48, which

causes thinning of the skin and could lead to cracking. Undetected cracking in the pressurized Section 46 could

reach sufficient length to cause in-flight depressurization of the airplane.

Prior to the release of Revision 1 of this service bulletin, BMS 10-86 Teflon filled coating along with primer has

shown to reduce wear caused by the movement of the vertical stabilizer seal on the fuselage skin. Boeing has

determined that primer and BMS 10-86 Teflon filled coating does not provide the required wear resistance.

Service Bulletin 747-53-2192, "Body-To-Vertical Fin Interface Seal Chafing Protection", dated July 21, 1981

provided operators of line numbers 0001 - 0414 with the option to apply enamel coating or BMS 10-86 Teflon

filled coating. Service bulletin 747-53-2192 was released after two operators reported seal wear damage on

four airplanes ranging in service time from 15,332 to 27,204 flight hours. Subsequent to Service Bulletin

747-53-2192 three operators reported seal wear damage on three airplanes ranging in service time from 8,265

to 40,805 flight hours. Service Bulletin 747-53-2192 is being replaced by this service bulletin, thereby eliminating

the option of enamel coating under the vertical stabilizer seal for airplane line numbers 0001 - 0414.

On airplanes after line number 1264, BMS 10-86 Teflon filled coating along with primer was applied at the vertical

stabilizer seal interface in Section 46 and Section 48 during production.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

7 of 52
BMS 10-86 Teflon filled coating was applied in Service Bulletin 747-53-2192 and the original issue of this service

bulletin to prevent skin wear damage, but is no longer terminating action for Revision 1 of this service bulletin.

Subsequent to the release of the original issue of this service bulletin, an operator reported seal wear damage

on three airplanes. The airplanes had received BMS 10-86 Teflon filled coating during production. The wear

damage had occurred on airplanes ranging in service time between from 21,318 to 26,432 flight hours. The

maximum depth of wear damage reported was 0.018 inches and was found on airplane line number 1300 with

a service time of 21,371 flight hours. Application of BMS 10-86 Teflon filled coating per Service Bulletin

747-53-2192 and the original issue of this service bulletin is no longer terminating action for this service bulletin.

Since the release of Revision 2 of this service bulletin, one operator has reported wear through the fuselage

skin between Body Station (STA) 2598 and STA 2638, stringers S-2L to S-3L. The wear developed in less than

3,657 flight hours since the previous inspection, which was less than the repeat inspection interval given in

Revision 2 of the service bulletin. The wear occurred through both the Teflon filled coating and the full thickness

of the 0.050 inch thick skin to create a hole approximately 16 inches in length.

Accomplishment of this service bulletin will ensure detection of crack and wear damage and provide proper

fuselage skin coating at the vertical stabilizer seal interface in Section 46 and Section 48.

Boeing Service Related Problem (SRP) 747-SRP-53-0161, 747-SRP-53-0296 and 747 FTD 53-06007 are

related to this service bulletin.

ACTION

Get access to the fuselage skin at the vertical stabilizer seal interface. Do a detailed inspection of the fuselage

skin for wear damage and cracks at the vertical stabilizer seal interface. In addition, if skin is blended in Section

46 and not reinforced, inspect the blended area with surface HFEC for cracks. If damage exists, repair in

accordance with the structural repair manual (SRM) or Boeing Service Bulletin 747-53-2721 . If any crack is

found or if wear exceeds SRM limits, also install rub strips in accordance with Boeing Service Bulletin 747-53-2721

. Apply BMS 10-86 Teflon filled coating as necessary. Clean the skin at the vertical stabilizer seal interface.

Follow-up with repeat visual or HFEC inspections. Optional: replace the seals and inspect for and repair paint

blistering at the vertical stabilizer seal interface.

As an alternative to repeated inspections, install CRES rub strips on the affected skin panels in accordance with

747-53-2721.

The skin panels affected by this service bulletin are divided into the following zones:

– Zone 1: STA 2280 to STA 2360 (STA 2340+40 to STA 2360 for 747LCF, STA 2072 to STA 2360 for 747SP)

– Zone 2: STA 2360 to STA 2397

– Zone 3: STA 2397 to STA 2417

– Zone 4: STA 2517 to STA 2557

– Zone 5: STA 2557 to STA 2598

– Zone 6: STA 2598 to STA 2638

NOTE: The SRM subjects referenced in this service bulletin have been updated to reflect new allowable

damage limits.

EFFECTIVITY

All 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F,

747SP, and 747SR series airplanes. Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplanes.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

8 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
COMPLIANCE

The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to this service

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

mandatory.

Federal Aviation Administration (FAA) Airworthiness Directive AD 2009-14-02 is related to this service bulletin.

Refer to Paragraph 1.E., Compliance.

INDUSTRY SUPPORT INFORMATION

Boeing warranty remedies are available for the original release of this service bulletin only for Group 1 airplanes

in warranty as of July 12, 2001. For inspection labor hour reimbursement for Group 1 airplanes in warranty as

of that date, send a warranty claim to Boeing Warranty. If the condition described in the original release of this

service bulletin is found during the inspection for Group 1 airplanes in warranty as of that date and additional

labor hours are required, send a warranty claim to Boeing Warranty. Please refer to this service bulletin number

and reference the airplane variable numbers in your purchase order.

Boeing warranty remedies are not available for either Group 1 or Group 2 airplanes for the additional work

required by Revision 1, Revision 2 or Revision 3 of this service bulletin.

MANPOWER

Total Task Elapsed Hours

Hours

Airplanes

Group 1 and Group 2 airplanes. 33.50 16.75

MATERIAL INFORMATION

Operator Supplied Parts/Materials.

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

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

9 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

10 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
Commercial 

Airplanes 747

Service Bulletin

ALERT

Number: 747-53A2478

Original Issue: February 07, 2002

Revision 3: October 17, 2011

ATA System: 5361

SUBJECT: FUSELAGE - Section 46 and Section 48 - Vertical Stabilizer Seal - Skin Damage

Protection at Seal Interface - Inspection and Repair

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

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

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

THE NEW OWNER.

1. PLANNING INFORMATION

A. Effectivity

1. Airplanes

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

Number, and Serial Number data.

This service bulletin is for the airplanes shown below.

NOTE: 747-8 and 747-8F series airplanes are not affected by this service bulletin.

GROUP CONFIGURATION DESCRIPTION

Line number 0001 - 1264 Airplanes that are in the effectivity of service

bulletin 747-53A2478 R0.

1 -

Line number 1265 and on. Airplanes that have received BMS 10-86

Teflon Filled Coating in production.

2 -

Airplane Models:

747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400,

747-400D, 747-400F, 747SP, 747SR

Variable Number Group

RA001 - RA034 1

RA101 - RA115 1

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

11 of 52
Variable Number Group

RA161 - RA164 1

RA201 - RA203 1

RA216 - RA217 1

RA245 - RA246 1

RA251 - RA266 1

RA301 - RA318 1

RA351 - RA360 1

RA369 - RA373 1

RA401 - RA418 1

RA501 - RA502 1

RA521 - RA528 1

RA532 - RA548 1

RA551 - RA552 1

RA559 - RA561 1

RA581 - RA582 1

RA585 1

RA601 - RA602 1

RA631 - RA635 1

RA651 - RA652 1

RA671 - RA677 1

RA701 - RA702 1

RA721 - RA731 1

RA741 - RA745 1

RA749 - RA750 1

RA761 - RA762 1

RA781 - RA784 1

RA901 - RA916 1

RB001 - RB016 1

RB041 - RB044 1

RB071 - RB075 1

RB101 - RB102 1

RB411 - RB413 1

RB421 1

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

12 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
Variable Number Group

RB601 - RB607 1

RB681 - RB697 1

RB711 1

RB721 - RB723 1

RB741 - RB748 1

RD001 - RD004 1

RD021 - RD022 1

RD041 - RD059 1

RD071 - RD072 1

RD081 - RD083 1

RD091 - RD092 1

RD101 - RD104 1

RD121 - RD127 1

RD131 - RD144 1

RD166 - RD167 1

RD171 - RD172 1

RD181 - RD183 1

RD201 - RD204 1

RD221 - RD227 1

RD231 - RD235 1

RD241 - RD243 1

RD251 - RD262 1

RD271 - RD272 1

RD291 - RD292 1

RD301 - RD302 1

RD311 1

RD351 - RD358 1

RD361 - RD366 1

RD381 - RD383 1

RD411 - RD414 1

RD421 - RD426 1

RD431 - RD435 1

RD441 - RD442 1

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

13 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
Variable Number Group

RD451 - RD456 1

RD461 1

RD471 - RD475 1

RD513 - RD519 1

RD531 - RD533 1

RD551 1

RD561 1

RD571 1

RD581 - RD583 1

RD591 - RD593 1

RD601 - RD607 1

RD621 - RD623 1

RD641 - RD649 1

RD651 - RD659 1

RD661 1

RD671 1

RD681 - RD682 1

RD691 - RD692 1

RD701 - RD702 1

RD721 - RD722 1

RD741 - RD742 1

RD751 - RD755 1

RD761 1

RD771 - RD775 1

RD781 - RD783 1

RD791 - RD792 1

RE001 1

RF001 - RF006 2

RG001 - RG009 1

RG091 1

RG095 1

RG101 - RG104 1

RG121 - RG126 1

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

14 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
Variable Number Group

RG141 - RG142 1

RG161 - RG164 1

RG171 - RG174 1

RG191 - RG193 1

RG211 - RG213 1

RG221 - RG222 1

RH101 - RH102 1

RH111 - RH112 1

RH121 - RH122 1

RJ131 - RJ133 1

RJ151 - RJ152 1

RJ301 - RJ303 1

RJ321 - RJ322 1

RJ331 - RJ333 1

RL401 1

RL402 - RL403 2

RL411 - RL414 1

RL415 - RL436 2

RL451 - RL456 2

RL461 - RL462 2

RL471 - RL481 2

RL491 - RL492 2

RL501 - RL502 2

RL511 - RL516 2

RL521 - RL522 2

RL531 - RL534 2

RL551 2

RL561 - RL568 2

RL571 - RL572 2

RL576 - RL577 2

RL579 2

RL581 - RL586 2

RL651 - RL653 1

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

15 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
Variable Number Group

RL654 - RL655 2

RL671 - RL675 2

RL681 - RL684 2

RL751 - RL752 2

RM001 - RM005 1

RM006 - RM007 2

RM010 2

RM011 - RM012 1

RM013 2

RM021 - RM024 1

RM026 - RM027 1

RM028 - RM030 2

RM036 - RM039 1

RM040 2

RM041 1

RM042 - RM045 2

RM051 1

RM052 - RM053 2

RM071 1

RM081 - RM084 1

RM091 1

RM096 - RM097 1

RM116 - RM117 1

RM126 - RM131 1

RM132 2

RM136 - RM147 1

RM156 - RM157 1

RM158 2

RM166 - RM177 1

RM191 - RM192 1

RM231 - RM233 1

RM241 - RM244 1

RM245 - RM246 2

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

16 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
Variable Number Group

RM261 - RM264 1

RM316 - RM318 1

RM331 - RM333 1

RM341 1

RM351 - RM355 2

RM366 - RM367 2

RM401 - RM403 2

RM426 2

RM431 2

RM441 - RM443 2

RM445 2

RM801 - RM802 1

RM803 2

RM811 - RM813 1

RM851 - RM853 1

RM854 - RM855 2

RM856 1

RM857 - RM859 2

RM861 1

RM862 - RM863 2

RM871 - RM873 1

RM874 - RM880 2

RM881 - RM885 1

RM886 - RM890 2

RM891 - RM899 1

RM901 - RM903 1

RM904 - RM906 2

RM911 1

RR001 - RR005 1

RR021 - RR025 1

RR031 1

RR201 - RR206 1

RR221 - RR226 1

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

17 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
Variable Number Group

RR261 - RR267 1

RR301 - RR310 1

RR331 - RR332 1

RR336 1

RR341 - RR345 1

RR361 - RR362 1

RR421 - RR422 1

RR431 - RR432 1

RR441 - RR442 1

RR451 1

RR501 - RR504 1

RR521 - RR522 1

RR526 1

RR531 1

RR551 - RR556 1

RR561 1

RR566 1

RR701 1

RR721 - RR724 1

RR746 - RR748 1

RR851 - RR856 1

RR861 - RR862 1

RR951 - RR952 1

RS001 - RS002 1

RS201 1

RS211 - RS212 1

RS221 - RS222 1

RS231 - RS241 1

RS251 - RS259 1

RS263 1

RS265 - RS268 1

RS271 - RS276 1

RS291 - RS292 1

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

18 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
Variable Number Group

RS301 - RS306 1

RS311 - RS320 1

RS331 - RS333 1

RS341 - RS342 1

RS699 1

RS701 - RS703 1

RS711 - RS713 1

RS721 - RS722 1

RS731 - RS732 1

RS741 - RS743 1

RS751 - RS752 1

RS761 - RS762 1

RS771 1

RS781 - RS782 1

RS786 1

RT001 - RT014 1

RT021 - RT022 1

RT031 - RT035 1

RT041 - RT047 1

RT061 1

RT071 - RT075 1

RT101 - RT103 1

RT121 1

RT131 - RT137 1

RT151 - RT152 1

RT161 - RT168 1

RT401 - RT412 1

RT431 - RT447 1

RT451 - RT469 1

RT471 - RT499 1

RT501 - RT535 1

RT551 - RT568 1

RT571 - RT591 1

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

19 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
Variable Number Group

RT601 - RT657 1

RT671 - RT673 1

RT681 - RT682 1

RT691 - RT699 1

RT701 - RT704 1

RT711 - RT717 1

RT741 - RT757 1

RT776 - RT777 1

RT781 - RT784 1

RT801 - RT803 1

RT811 - RT814 1

RT831 - RT837 1

RT861 - RT864 1

RT876 - RT880 1

RT931 - RT932 1

RT945 - RT949 1

RT951 - RT955 1

RT966 - RT967 1

RU001 - RU006 1

RU016 - RU017 1

RU031 - RU032 1

RU051 - RU052 1

RU059 - RU062 1

RU081 - RU083 1

RU101 - RU102 1

RU121 - RU132 1

RU801 - RU809 1

RU831 - RU841 1

2. Spares Affected

None.

B. Concurrent Requirements

None.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

20 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
C. Reason

Accomplishment of this service bulletin will detect cracks and accelerated skin wear damage from the

vertical stabilizer seal beyond allowable limits. The fuselage skin is subject to wear damage in the area

of the vertical stabilizer seal interface in Section 46 (Section 47 on 747-400 Large Cargo Freighter,

LCF) and Section 48, which causes thinning of the skin and could lead to cracking. Undetected cracking

in the pressurized Section 46 could reach sufficient length to cause in-flight depressurization of the

airplane.

The vertical stabilizer seals are located at the interface between vertical stabilizer and fuselage skin

between Body Station (BS) 2280 to BS 2416 and BS 2521 to BS 2598. Small movements of the vertical

stabilizer seal cause wear through the enamel coating or primer. Prior to the release of Revision 1 of

this service bulletin, BMS 10-86 Teflon filled coating along with primer has shown to reduce wear

caused by the movement of the vertical stabilizer seal on the fuselage skin. Boeing has determined

that primer and BMS 10-86 Teflon filled coating does not provide the required wear resistance.

Service Bulletin 747-53-2192, "Body-To-Vertical Fin Interface Seal Chafing Protection", dated July 21,

1981 provided operators of line numbers 0001 - 0414 with the option to apply enamel coating or BMS

10-86 Teflon filled coating. Service Bulletin 747-53-2192 was released after two operators reported

seal wear damage on four airplanes ranging in service time from 15,332 to 27,204 flight hours.

Subsequent to Service Bulletin 747-53-2192 three operators reported seal wear damage on three

airplanes ranging in service time from 8,265 to 40,805 flight hours. Service Bulletin 747-53-2192 is

being replaced by this service bulletin, thereby eliminating the option of enamel coating under the

vertical stabilizer seal for airplane line numbers 0001 - 0414.

On airplanes after line number 1264, BMS 10-86 Teflon filled coating along with primer was applied at

the vertical stabilizer seal interface in Section 46 and Section 48 during production.

BMS 10-86 Teflon filled coating was applied in Service Bulletin 747-53-2192 and the original issue of

this service bulletin to prevent skin wear damage, but is no longer terminating action for Revision 1 of

this service bulletin. Subsequent to the release of the original issue of this service bulletin, an operator

reported seal wear damage on three airplanes. The airplanes had received BMS 10-86 Teflon filled

coating during production. The wear damage had occurred on airplanes ranging in service time between

from 21,318 to 26,432 flight hours. The maximum depth of wear damage reported was 0.018 inches

and was found on airplane line number 1300 with a service time of 21,371 flight hours. Application of

BMS 10-86 Teflon filled coating per Service Bulletin 747-53-2192 and the original issue of this service

bulletin is no longer terminating action for Revision 1 of this service bulletin.

Since the release of Revision 2 of this service bulletin, one operator has reported wear through the

fuselage skin between Body Station (STA) 2598 and STA 2638, stringers S-2L to S-3L. The wear

developed in less than 3,657 flight hours since the previous inspection, which was less than the repeat

inspection interval given in Revision 2 of the service bulletin. The wear occurred through both the Teflon

filled coating and the full thickness of the 0.050 inch thick skin to create a hole approximately 16 inches

in length.

Accomplishment of this service bulletin will ensure detection of cracks and wear damage and / or cracks

and provide proper fuselage skin coating at the vertical stabilizer seal interface in Section 46 and

Section 48.

Boeing Service Related Problem (SRP) 747-SRP-53-0161, 747-SRP-53-0296 and 747 FTD 53-06007

are related to this service bulletin.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

21 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
Revision 1 was sent to tell operators that recent service history indicates that application of BMS 10-86

Teflon filled coating is no longer terminating action for the prevention of wear damage in Section 46

and Section 48 of the vertical stabilizer seal interface.

Changes to this service bulletin include:

— Paragraph 1.A., Effectivity. Airplanes line number 1265 and on have been added to the effectivity

of this service bulletin.

— Paragraph 1.A., Effectivity. Group effectivity has been revised. Group 2 in the original issue of this

service bulletin has been added to Group 1 in this service bulletin. Airplanes through line number

1265 and on have been added to Group 2 of this service bulletin

— Paragraph 1.E., Compliance. Compliance times have been revised and repeat inspections have

been added for all airplanes. A note is also added to inform operators that application of BMS

10-86 Teflon filled coating is no longer terminating action.

— Paragraph 1.F., Manpower. The manpower table has been revised to account for the time taken

to accomplish inspection for wear damage of Group 2 airplanes.

— Paragraph 3.B.3., Work Instructions. Work has been added for airplanes that do not have wear

damage.

— Figure 1 has been deleted to remove the logic diagram.

— In Figure 3, Step 2 has been added to show an inspection for skin cracks in blended areas forward

of STA 2360.

Revision 2 was sent to add references to Boeing Service Bulletin 747-53-2721, which gives instructions

to install CRES steel rub strips in areas affected by this service bulletin. The inspections in this service

bulletin are no longer necessary after the modification in Service Bulletin 747-53-2721 has been installed.

In addition, references to skin repairs, including kits, that are in Service Bulletin 747-53-2721 have

been included. The Summary illustration and the locators in Figures 2, 3 and 4 have been changed to

more clearly show that the inspections in this service bulletin should be done up to STA 2628, not STA

2598. The location wrongly identified as STA 2598 in the previous releases of this service bulletin is

actually STA 2628. The Action paragraph in the Summary, Paragraph 1.D., Description, Paragraph

1.E., Compliance, and FIGURE 3 have been changed to make it clear that affected areas of skin in

Section 46 (areas forward of STA 2360) that have been blended without reinforcement should be

inspected for cracks with external surface High Frequence Eddy Current (HFEC), in addition to external

detailed inspections. Instructions for repair of fasteners with wear damage have been added to new

PART 2 in Paragraph 3.B., Work Instructions. References to FAA AD 2009-14-02 have been added.

AD 2009-14-02 superseded AD 2002-26-15. The data given in Information Notice 747-53A2478 IN 01

is included in this revision. IN 01 was sent to clarify footnote (b) in Figure 3, which describes the surface

HFEC inspections required in blended skin areas.

Revision 3 is sent to change the repeat inspection requirements for all airplanes, to add the requirement

for rub strip installation for airplanes with wear or blend that exceeds Structural Repair Manual limits

and to add the requirement to clean the skin at each inspection interval.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

22 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
D. Description

Get access to the fuselage skin at the vertical stabilizer seal interface. Do a detailed inspection of the

fuselage skin for wear damage and cracks at the vertical stabilizer seal interface. In addition, if skin is

blended in Section 46 and not reinforced, inspect the blended area with surface HFEC for cracks. If

damage exists, repair in accordance with the structural repair manual (SRM) or Boeing Service Bulletin

747-53-2721 . If any crack is found or if wear exceeds SRM limits, also install rub strips in accordance

with Boeing Service Bulletin 747-53-2721 . Apply BMS 10-86 Teflon filled coating as necessary. Clean

the skin at the vertical stabilizer seal interface. Follow-up with repeat visual or HFEC inspections.

Optional: replace the seals and inspect for and repair paint blistering at the vertical stabilizer seal

interface.

As an alternative to repeated inspections, install CRES rub strips on the affected skin panels in

accordance with 747-53-2721.

The skin panels affected by this service bulletin are divided into the following zones:

– Zone 1: STA 2280 to STA 2360 (STA 2340+40 to STA 2360 for 747LCF, STA 2072 to STA 2360

for 747SP)

– Zone 2: STA 2360 to STA 2397

– Zone 3: STA 2397 to STA 2417

– Zone 4: STA 2517 to STA 2557

– Zone 5: STA 2557 to STA 2598

– Zone 6: STA 2598 to STA 2638

NOTE: The SRM subjects referenced in this service bulletin have been updated to reflect new allowable

damage limits.

Revision 1 - More work is necessary on airplanes changed in accordance with the original issue of this

service bulletin. Repeat inspections are necessary for all airplanes. Application of BMS 10-86 Teflon

filled coating is no longer terminating action for the inspections given in this service bulletin.

Revision 2 - No more work is necessary on airplanes inspected in accordance with Revision 1 of this

service bulletin. Continue to do repeat inspections in accordance with Revision 2.

Revision 3 - More work is necessary on the airplane(s) changed in accordance with Revision 1 or

Revision 2 of this service bulletin. Do repeat inspections in accordance with Revision 3.

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

Group 1:

Affected Maintenance Zones

Model Zone

747-100, 747-100B, 747-100B 311, 312, 313, 314

SUD, 747-200B, 747-200C,

747-200F, 747-300, 747-400,

747-400D, 747-400F, 747SP,

747SR

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

23 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
Group 2:

Affected Maintenance Zones

Model Zone

747-400, 747-400F 311, 312, 313, 314

E. Compliance

The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to

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

service bulletin mandatory.

Federal Aviation Administration (FAA) Airworthiness Directive AD 2009-14-02 is related to this service

bulletin.

Table 1 - Inspection for wear damage and cracks

Repeat Interval

(Not to Exceed)

Condition Action Compliance Time

In accordance with Table -

2.

Do initial inspection and modify/repair as necessary in accordance with Table 2. (b) (c)All airplanes.

(a)

In accordance with Table Refer to Table 3

3.

Do repeat inspections and

modify/repair as necessary in

accordance with Table 3. (c)

In accordance with Table Refer to Table 4

4.

Do inspections and modify/repair in accordance with Table 4.

(c)

Airplanes with fuselage skin

blended without external reinforcement in Section 46.

(a) Refer to Boeing Service Bulletin 747-53-2721 or contact Boeing if CRES rub strips are installed.

(b) For airplanes that have started inspections in accordance with the original issue, Revision 1 or Revision

2 of this service bulletin, initial inspections in accordance with Revision 3 of this service bulletin are necessary unless terminating action has been accomplished.

(c) It is acceptable to install rub strips in accordance with Boeing Service Bulletin 747-53-2721 at any time.

Installation of rub strips in accordance with Boeing Service Bulletin 747-53-2721 is terminating action for

the work given in this service bulletin at the locations of rub strip installation only.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

24 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
Table 2 - Initial inspection for wear damage and cracks, and application of BMS 10-86 Teflon filled

coating.

Condition Action Compliance Time

Do a detailed inspection of the Whichever Occurs Later:

fuselage skin at the vertical stabilizer seal interface for wear

damage and cracks, and clean

the skin, in accordance with

Paragraph 3.B., Work Instructions, PART 1. Where skin repair doubler is present, inspect

the surface of the repair doubler. Removal of the repair doubler is not necessary.

Airplanes that have not started

inspections in accordance with

the original issue, Revision 1 or

Revision 2 of this service bulletin.

(c)

Within 6,000 flight

hours after the effective date of FAA AD

2009-14-02 or within

2,000 flight hours after the Revision 3

date of this service

bulletin, whichever

occurs first.

Before 20,000 total

flight hours.

(a) (b) (d) (e) (h)

Do a detailed inspection of the Whichever Occurs First:

fuselage skin at the vertical stabilizer seal interface for wear

damage and cracks, and clean

the skin, in accordance with

Paragraph 3.B., Work Instructions, PART 1. Where skin repair doubler is present, inspect

the surface of the repair doubler. Removal of the repair doubler is not necessary.

Airplanes that have started inspections in accordance with

the original issue, Revision 1 or

Revision 2 of this service bulletin and, after the last work in

accordance with this service

bulletin, one of the following

conditions applied in the fuselage skin at the vertical stabilizer

seal interface:

- there were no blend repairs

Within 2,000 flight

hours after the Revision 3 date of this

service bulletin, or

within 3,000 flight

hours after the previous inspection in accordance with the

original issue, Revision 1 or Revision 2,

whichever occurs later.

Within 7,500 flight

hours after the previous inspection in accordance with the

original issue, Revision 1 or Revision 2

of this service bulletin.

or (a) (b) (d) (e) (h)

- the maximum blend repair

depth was 0.006 inches or less.

(c) (j) (k)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

25 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
Table 2 - Initial inspection for wear damage and cracks, and application of BMS 10-86 Teflon filled

coating.

Condition Action Compliance Time

Do a detailed inspection of the Whichever Occurs First:

fuselage skin at the vertical stabilizer seal interface for wear

damage and cracks, and clean

the skin, in accordance with

Paragraph 3.B., Work Instructions, PART 1. Where skin repair doubler is present, inspect

the surface of the repair doubler. Removal of the repair doubler is not necessary.

Airplanes that have started inspections in accordance with

the original issue, Revision 1 or

Revision 2 of this service bulletin and, after the last work in

accordance with this service

bulletin, one of the following

conditions applied in the fuselage skin at the vertical stabilizer

seal interface:

- the maximum blend repair

depth was more than 0.006

inches

Within 2,000 flight

hours after the Revision 3 date of this

service bulletin.

Within 7,500 flight

hours after the previous inspection in accordance with the

original issue, Revision 1 or Revision 2

of this service bulletin.

(a) (b) (d) (e) (h)

or

- the maximum blend repair

depth was not recorded

or

- it is not known if there were

any blend repairs.

(c) (j) (k)

Repair wear damage and apply Before further flight.

BMS 10-86 Teflon filled coating

in accordance with Paragraph

3.B., Work Instructions , PART

1.

Wear damage is found that is

less than or equal to the rework

limit allowed in the SRM. (f)

(g) (h) (i)

Repair wear damage and/or Before further flight.

crack, and apply BMS 10-86

Teflon filled coating in accordance with Paragraph 3.B.,

Work Instructions , PART 1.

Wear damage is found that is

more than the rework limit allowed in the SRM. (f)

OR

Crack is found.

(g) (h)

AND

Install rub strips at all locations Within 24 months after finding the condition.

in accordance with Boeing Service Bulletin 747-53-2721.

(e) (h)

Apply BMS 10-86 Teflon filled Before further flight.

coating in accordance with

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

No wear damage or crack is

found.

(g) (h)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

26 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
Table 2 - Initial inspection for wear damage and cracks, and application of BMS 10-86 Teflon filled

coating.

Condition Action Compliance Time

Repair skin and apply BMS 10- Before further flight.

86 Teflon filled coating in accordance with Paragraph 3.B.,

Work Instructions, PART 1.

Wear damage is repaired using

blend method and, after the repair, the blend depth is more

than the rework limit allowed in

the SRM. (f) (g) (h)

AND

Install rub strips at all locations Within 24 months after finding the condition.

in accordance with Boeing Service Bulletin 747-53-2721.

(e) (h)

(a) Application of BMS 10-86 Teflon filled coating is no longer terminating action for the inspections.

(b) If repair doubler is installed in accordance with 747-100/200/300 SRM 53-30-03, 747-400 SRM 53-00-01,

747-400F SRM 53-00-01, 747-400SF SRM 53-00-01, 747-SP SRM 53-39-01, or 747-400LCF SRM 53-

00-01, inspections in accordance with the SRM are also required.

(c) Refer to Boeing Service Bulletin 747-53-2721 or contact Boeing if CRES rub strips are installed.

(d) If skin thickness in Section 46 is reduced by blending without reinforcement, Table 4 also applies.

(e) In areas repaired or modified in accordance with Boeing Service Bulletin 747-53-2721, continue inspections

in the repaired or modified areas in accordance with Boeing Service Bulletin 747-53-2721.

(f) Refer to 747-100/200/300 SRM 53-30-01, 747-SP SRM 53-31-00, 747-400 SRM 53-00-01, 747-400F

SRM 53-00-01, 747-400SF SRM 53-00-01, or 747-400LCF SRM 53-00-01 for rework limits.

(g) It is not necessary to apply BMS 10-86 Teflon filled coating at locations where rub strips are installed in

accordance with Boeing Service Bulletin 747-53-2721 before further flight.

(h) It is acceptable to install rub strips in accordance with Boeing Service Bulletin 747-53-2721 at any time.

Installation of rub strips in accordance with Boeing Service Bulletin 747-53-2721 is terminating action for

the work given in this service bulletin at the locations of rub strip installation only.

(i) The repeat inspection conditions given in Table 3 are dependent on maximum blend depth after repair. If

blend repair is used, it is recommended to record the maximum blend depth after blend repair so that the

next repeat interval can be determined. (j)

(j) Maximum blend repair depth is the depth of the blend repair at the location where the blend depth is

largest. The blend depth is the total depth of material removed from the skin, based on the original skin

thickness.

(k) This condition applies to the time after the last work was done in accordance with this service bulletin before

starting inspections in accordance with Revision 3 of this service bulletin.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

27 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
Table 3 - Repeat inspections for wear damage and cracks, and application of BMS 10-86 Teflon filled

coating

Repeat Interval

(Not to Exceed)

(j)

Condition Action Compliance Time (j)

3,000 flight hours

(h) (i)

Within 3,000 flight hours

after the previous inspection in accordance with

this service bulletin.

Do a detailed inspection of the

fuselage skin at the vertical stabilizer seal interface for wear

damage and cracks, and clean

the skin, in accordance with

Paragraph 3.B., Work Instructions, PART 1. Where skin repair doubler is present, inspect

the surface of the repair doubler. Removal of the repair doubler is not necessary.

Airplanes for which, in the fuselage skin at the vertical stabilizer

seal interface:

- there are no blend repairs

or

- the maximum blend repair

depth is 0.006 inches or less.

(c) (k)

(a) (b) (d) (e) (i)

2,000 flight hours

(h) (i)

Within 2,000 flight hours

after the previous inspection in accordance with

this service bulletin.

Do a detailed inspection of the

fuselage skin at the vertical stabilizer seal interface for wear

damage and cracks, and clean

the skin, in accordance with

Paragraph 3.B., Work Instructions, PART 1. Where skin repair doubler is present, inspect

the surface of the repair doubler. Removal of the repair doubler is not necessary.

Airplanes for which, in the fuselage skin at the vertical stabilizer

seal interface:

- the maximum blend repair

depth is more than 0.006 inches

and less than or equal to the

rework limit allowed in the SRM.

(f)

or

- the maximum blend repair

depth is not known

or (a) (b) (d) (e) (i)

- it is not known if there are any

blend repairs.

(c) (k)

2,000 flight hours

(i)

Within 2,000 flight hours

after the previous inspection in accordance with

this service bulletin.

Do a detailed inspection of the

fuselage skin at the vertical stabilizer seal interface for wear

damage and cracks, and clean

the skin, in accordance with

Paragraph 3.B., Work Instructions, PART 1. Where skin repair doubler is present, inspect

the surface of the repair doubler. Removal of the repair doubler is not necessary.

Airplanes for which, in the fuselage skin at the vertical stabilizer

seal interface:

- there has been skin wear or

blend repair greater than the

rework limit allowed in the SRM

since the release of Revision 3

of this service bulletin. (f)

(c)

(a) (b) (d) (e) (i)

AND

Within 24 months after -

finding the condition.

Install rub strips at all locations

in accordance with Boeing Service Bulletin 747-53-2721.

(e) (i)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

28 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
Table 3 - Repeat inspections for wear damage and cracks, and application of BMS 10-86 Teflon filled

coating

Repeat Interval

(Not to Exceed)

(j)

Condition Action Compliance Time (j)

Repair wear damage and apply Before further flight. -

BMS 10-86 Teflon filled coating,

in accordance with Paragraph

3.B., Work Instructions, PART

1.

Wear damage is found that is

less than or equal to the rework

limit allowed in the SRM. (f)

(g) (j) (i)

Repair wear damage and/or Before further flight. -

crack, and apply BMS 10-86

Teflon filled coating, in accordance with Paragraph 3.B.,

Work Instructions, PART 1.

Wear damage is found that is

more than the rework limit allowed in the SRM. (f)

OR

Crack is found.

(g) (i)

AND

Within 24 months after -

finding the condition.

Install rub strips at all locations

in accordance with Boeing Service Bulletin 747-53-2721.

(e) (i)

Apply BMS 10-86 Teflon filled Before further flight. -

coating in accordance with

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

No wear damage or crack is

found.

(g) (i)

Repair skin and apply BMS 10- Before further flight. -

86 Teflon filled coating in accordance with Paragraph 3.B.,

Work Instructions, PART 1.

Wear damage is repaired using

blend method and, after the repair, the blend is more than the

rework limit allowed in the SRM.

(f) (g) (i)

AND

Within 24 months after -

finding the condition.

Install rub strips at all locations

in accordance with Boeing Service Bulletin 747-53-2721.

(e) (i)

(a) Application of BMS 10-86 Teflon filled coating is no longer terminating action for the repeat inspections

(b) If repair doubler is installed in accordance with 747-100/200/300 SRM 53-30-03, 747-400 SRM 53-00-01,

747-400F SRM 53-00-01, 747-400SF SRM 53-00-01, 747-SP SRM 53-39-01, or 747-400LCF SRM 53-

00-01, inspections in accordance with the SRM are also required.

(c) Refer to Boeing Service Bulletin 747-53-2721 or contact Boeing if CRES rub strips are installed.

(d) If skin thickness in Section 46 is reduced by blending without reinforcement, Table 4 also applies.

(e) In areas repaired or modified in accordance with Boeing Service Bulletin 747-53-2721, continue inspections

in the repaired or modified areas in accordance with Boeing Service Bulletin 747-53-2721.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

29 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
Table 3 - Repeat inspections for wear damage and cracks, and application of BMS 10-86 Teflon filled

coating

Repeat Interval

(Not to Exceed)

(j)

Condition Action Compliance Time (j)

(f) Refer to 747-100/200/300 SRM 53-30-01, 747-SP SRM 53-31-00, 747-400 SRM 53-00-01, 747-400F

SRM 53-00-01, 747-400SF SRM 53-00-01, or 747-400LCF SRM 53-00-01 for rework limits.

(g) It is not necessary to apply BMS 10-86 Teflon filled coating at locations where rub strips are installed in

accordance with Boeing Service Bulletin 747-53-2721 before further flight.

(h) This repeat inspection is terminated if the blend depth becomes more than is stated in the condition. Refer

to the new applicable Condition for the required Action, Compliance Time and Repeat Interval.

(i) It is acceptable to install rub strips in accordance with Boeing Service Bulletin 747-53-2721 at any time.

Installation of rub strips in accordance with Boeing Service Bulletin 747-53-2721 is terminating action for

the work given in this service bulletin at the locations of rub strip installation only.

(j) The repeat inspection conditions are dependent on maximum blend depth after repair. If blend repair is

used, it is recommended to record the maximum blend depth after blend repair so that the next repeat

interval can be determined. (k)

(k) Maximum blend repair depth is the depth of the blend repair at the location where the blend depth is

largest. The blend depth is the total depth of material removed from the skin, based on the original skin

thickness.

Table 4 - Inspection for cracks on airplanes that have reduced skin thickness in Section 46 due to

blending without reinforcement

Repeat Interval

(Not to Exceed)

Compliance Time

(Whichever Occurs Later)

Condition Action

6,000 flight cycles. (d)Within 1,000

flight cycles after the effective

date of FAA

AD 2009-14-02

Before 20,000

total flight cycles, or within

6,000 flight cycles after the

initial blend,

whichever occurs later.

Do an external surface HFEC

inspection of the blended area

of the fuselage skin for cracks,

in accordance with Paragraph

3.B., Work Instructions , PART

1. Where skin repair doubler is

present, inspect the surface of

the repair doubler. Removal of

the repair doubler is not necessary. (a) (b) (c) (d)

Fuselage skin blended

without external reinforcement.

Repair crack and apply BMS 10- Before further flight. -

86 Teflon filled coating, in accordance with Paragraph 3.B.,

Work Instructions , PART 1.

Crack is found.

(d)

Apply BMS 10-86 Teflon filled Before further flight. -

coating, in accordance with

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

No crack is found.

(d)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

30 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
Table 4 - Inspection for cracks on airplanes that have reduced skin thickness in Section 46 due to

blending without reinforcement

Repeat Interval

(Not to Exceed)

Compliance Time

(Whichever Occurs Later)

Condition Action

(a) If there is a knife edge condition at any fastener hole in the blended area (i.e. countersink depth greater

than 2/3 of the existing skin thickness), repair in accordance with Paragraph 3.B., Accomplishment Instructions, before further flight. After the repair, continue inspection in accordance with Table 1.

(b) Repeat this inspection until repair doubler is installed in the blended area as given 747-100/200/300 SRM

53-30-03, 747-400 SRM 53-00-01, 747-400F SRM 53-00-01, 747-400SF SRM 53-00-01, 747-SP SRM

53-39-01 or 747-400LCF SRM 53-00-01. After an SRM repair, if no rub strip was installed, continue inspections in the repaired area in accordance with Table 1.

(c) In areas repaired or modified in accordance with Boeing Service Bulletin 747-53-2721, continue inspections

in the repaired or modified areas in accordance with Boeing Service Bulletin 747-53-2721.

(d) It is acceptable to install rub strips in accordance with Boeing Service Bulletin 747-53-2721 at any time.

Installation of rub strips in accordance with Boeing Service Bulletin 747-53-2721 is terminating action for

the work given in this service bulletin at the locations of rub strip installation only.

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.

This service bulletin has been approved by the Federal Aviation Administration (FAA). In addition, the

Manager of the FAA Seattle Aircraft Certification Office (ACO) approves the inspection, repair, and

modification procedures with the corresponding compliance times specified in Tables 1, 2, 3 and 4

under paragraph 1.E., "Compliance" of Service Bulletin 747-53A2478, Revision 3, as an Alternative

Method of Compliance (AMOC) to the inspections, corrective actions, and terminating actions required

by paragraphs (f), (i), (k), and (l) of AD 2009-14-02. This AMOC only applies to the areas inspected,

repaired, or modified in accordance with this service bulletin. Installation of rub strips in accordance

with Boeing Service Bulletin 747-53-2721 is terminating action for the work given in AD 2009-14-02 at

the locations of rub strip installation only. When this service bulletin specifies contacting Boeing for

repair instructions, the repair instructions must be approved by the FAA in accordance with paragraph

(m) of the AD. All provisions of AD 2009-14-02 that are not specifically referenced in this paragraph

remain fully applicable and must be complied with.

G. Manpower

The following table 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:

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

31 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
— 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.

Number of Per- Task Hours Elapsed Hours

sons

Task

Open access 2 5.00 2.50

Visually inspect for 2 2.00 1.00

wear

Apply BMS 10-86 2 6.00 3.00

Teflon filled coating

Replace seals (b) 2 12.50 6.25

Inspect for soften- 2 1.50 0.75

ing/blistering of finish (b)

Clean skin 2 1.50 0.75

Close access 2 5.00 2.50

TOTAL FOR EACH AIRPLANE (a) 33.50 16.75

(a) Estimate does not include time for repairs.

(b) These task are optional.

H. Weight and Balance Changes

None.

I. Electrical Load Data

Not changed.

J. References

1. Existing Data:

a. 747 Maintenance Manual (AMM) Subjects 51-24-04, 55-30-10

b. 747-SP Structural Repair Manual (SRM) 51-30-08, 53-31-00, 53-39-01

c. 747-100/200/300 Structural Repair Manual (SRM) 51-30-08, 53-30-01, 53-30-03

d. 747-400 Structural Repair Manual (SRM) 51-40-08, 53-00-01

e. 747-400F Structural Repair Manual (SRM) 51-40-08, 53-00-01

f. 747-400LCF Structural Repair Manual (SRM) 51-40-08, 53-00-01

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

32 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
g. 747-400SF Structural Repair Manual (SRM) 51-40-08, 53-00-01

h. Boeing Service Bulletin 747-53-2192, 747-53-2721

i. Boeing Service Related Problem (SRP) 747-SRP-53-0161, 747-SRP-53-0296

j. Federal Aviation Administration (FAA) Airworthiness Directive 2002-26-15, 2009-14-02

k. 747-400SF Structural Repair Manual (SRM) 51-40-08, 53-00-01

l. 747-400LCF Structural Repair Manual (SRM) 53-00-01

m. 747 NDT Part 6, 51-00-00, Figure 4 or 23

n. 747 Repair Assessment Guidelines (RAG) D6-36181

o. Boeing Standard Overhaul Practices Manual (SOPM) 20-30-03, 20-41-02, 20-44-01

p. 747 Fleet Team Digest (FTD) 53-06007

2. Data supplied with this Service Bulletin:

None.

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

Drawing Number Title

146U3910 Skin Panel Assembly - STA 2181.10 to 2360, Str 4L to Str 4R

65B02706 Panel Instl - S-1 to S-11, STA 2360 - 2598

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:

Publication Chapter-Section

747-100/-200/-300 Structural Repair Manual 53-30-01, 53-30-03

747-400 Structural Repair Manual 53-00-01

747 SP Structural Repair Manual 53-31-00, 53-39-01

747-400F Structural Repair Manual 53-00-01

747 E4B Structural Repair Manual 53-30-01, 53-30-03

747LCF Structural Repair Manual 53-00-01

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

33 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
Publication Chapter-Section

747SF Structural Repair Manual 53-00-01

2. Damage Tolerance Based Structural Inspections:

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

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

in the Maintenance Program. This service bulletin revision affects FCS but no new DTIs are

necessary.

L. Interchangeability and Intermixability of Parts

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

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

34 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
2. MATERIAL INFORMATION

A. Material - Price and Availability

None.

B. Industry Support Information

Boeing warranty remedies are available for the original release of this service bulletin only for Group

1 airplanes in warranty as of July 12, 2001. For inspection labor hour reimbursement for Group 1

airplanes in warranty as of that date, send a warranty claim to Boeing Warranty. If the condition described

in the original release of this service bulletin is found during the inspection for Group 1 airplanes in

warranty as of that date and additional labor hours are required, send a warranty claim to Boeing

Warranty. Please refer to this service bulletin number and reference the airplane variable numbers in

your purchase order.

Boeing warranty remedies are not available for either Group 1 or Group 2 airplanes for the additional

work required by Revision 1, Revision 2 or Revision 3 of this service bulletin.

C. Parts Necessary For Each Airplane

1. Kits/Parts:

None.

2. Parts and Materials Supplied by the Operator:

Part Number / QTY Name Notes

Specification

(a) 16 oz Primer (c)

(b) 16 oz Teflon Filled Coating (c)

(a) Use one of the following primers; BMS 10-79 Type III, BMS 10-79 Type II, or BMS 10-11

Type I.

(b) Use one of the following Teflon filled coatings; BMS 10-86 Type I or BMS 10-86 Type II.

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

supplier data.

3. Parts Modified and Reidentified:

None.

4. Parts Removed and Not Replaced:

None.

D. Parts Necessary to Change Spares

None.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

35 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
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.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

36 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
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 are given in 747 SRM, Chapter 51

– Torque limits to tighten nuts and bolts are given in 747 SRM, Chapter 51

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

the 747 SRM 51.

5. If the length of any fastener specified in this service bulletin does not meet the

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.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

37 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
9. This service bulletin contains instructions to remove and keep parts for installation.

However, before installation of any removed and kept part, the part must be in a

serviceable condition. Replacement of the removed and kept part with a new or

serviceable part of the same part number/specification is an acceptable alternative

unless otherwise stated in the service bulletin instructions.

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. Boeing has determined that the condition of the seals and the skin finish (or paint)

in the vertical stabilizer seal interface area may contribute to skin wear. Degraded

seals and contaminants/debris at the vertical stabilizer seal interface, from softening,

blistering or flaking of the skin finish, can accelerate skin wear. Excessive skin wear

will require extensive repairs. To make sure that excessive wear does not occur

between inspections Boeing recommends operator accomplish Paragraph 3.B., Work

Instructions, Part 3 - Economic Based Additional Inspections and Procedures

(Operator Option), at each skin inspection.

13. It is acceptable to install rub strips in accordance with Boeing Service Bulletin

747-53-2721 at any time. Installation of rub strips in accordance with Boeing Service

Bulletin 747-53-2721 is terminating action for the work given in this service bulletin

at the locations of rub strip installation only.

B. WORK INSTRUCTIONS

PART 1 - INSPECTION

1. Get access. Refer to FIGURE 2 as an accepted procedure.

NOTE: It is also acceptable to get access for inspections by lifting the seal with a finger or plastic

instrument.

2. Do a detailed inspection of the fuselage skin for wear and cracks at the vertical stabilizer seal

interface in accordance with FIGURE 3. If skin is blended forward of STA 2360 without external

reinforcement, also do external surface High Frequency Eddy Current (HFEC) inspections for

cracks in accordance with FIGURE 3.

a. If wear is found, measure and record the depth of the wear and location.

(1) FOR WEAR IN SECTION 46 (FORWARD OF STA 2360) (Zone 1):

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

38 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
(a) If the head of any fastener in the affected area is worn beyond 0.002 inch deep (not

including paint and primer), replace the fastener in accordance with PART 2.

(b) If depth of wear in fuselage skin has exceeded the rework limits given in

747-100/200/300 SRM 53-30-01, 747-SP SRM 53-31-00, 747-400 SRM 53-00-01,

747-400F SRM 53-00-01, 747-400SF SRM 53-00-01, or 747-400LCF SRM 53-00-01,

do the following:

1) Do one of the following to repair the wear damage:

a) Repair the wear damage in accordance with 747-100/200/300 SRM

53-30-03, 747-400 SRM 53-00-01, 747-SP SRM 53-39-01, 747-400F SRM

53-00-01, 747-400SF SRM 53-00-01 or 747-400LCF SRM 53-00-01.

b) Install a full-length repair in Zone 1 in accordance with Boeing Service

Bulletin 747-53-2721.

c) Repair the wear damage and install rub strips in the affected areas in

accordance with Boeing Service Bulletin 747-53-2721.

2) Install rub strips at all locations in accordance with Boeing Service Bulletin

747-53-2721.

(c) If depth of wear in fuselage skin is within the rework limits given in 747-100/200/300

SRM 53-30-01, 747-SP SRM 53-31-00, 747-400 SRM 53-00-01, 747-400F SRM

53-00-01, 747-400SF SRM 53-00-01, or 747-400LCF SRM 53-00-01, do one of the

following options:

1) Option 1 - Blend repair:

Do the following:

NOTE: Depending on the extent and location of the wear, it might not be

possible to accomplish a blend repair and comply with the rework limits

given in the applicable SRM. If the rework limits in the applicable SRM

are exceeded, more repair work will be necessary. Refer to Paragraph

3.B., Work Instructions PART 1 step 2.a.(1)(c)1)b).

a) Repair the skin panel using the blend method in accordance with

747-100/200/300 SRM 53-30-01, Figure 1, Flagnote D, 747-400 SRM

53-00-01, Allowable Damage 1, Flagnote F, 747-SP SRM 53-31-00, Figure

1, Flagnote F, 747-400F SRM 53-00-01, Allowable Damage 1, Flagnote F,

747-400SF SRM 53-00-01, Allowable Damage 1, Flagnote F, or 747-400LCF

SRM 53-00-01, Allowable Damage 1, Flagnote F.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

39 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
NOTE: 1. Observe minimum distance of cleanout boundary from

fastener holes as stated in the SRM.

2. Based on the original nominal design skin thickness, for

any rework the total depth of material removed from the

skin must not exceed the "MAXIMUM ALLOWABLE

REWORK DEPTH" given in the applicable SRM.

3. It is recommended to record the maximum blend depth

after blend repair so that the next repeat interval can be

determined.

4. The maximum blend depth after blend repair is the depth

of the blend repair at the location where the blend depth

is largest. The blend depth is the total depth of material

removed from the skin, based on the original skin

thickness.

b) After doing the blend repair, if the blend depth is not within the rework limits

given in 747-100/200/300 SRM 53-30-01, 747-SP SRM 53-31-00, 747-400

SRM 53-00-01, 747-400F SRM 53-00-01, 747-400SF SRM 53-00-01, or

747-400LCF SRM 53-00-01, do the following:

{1} Repair the skin panel in accordance with 747-100/200/300 SRM

53-30-03, 747-400 SRM 53-00-01, 747-SP SRM 53-39-01, 747-400F

SRM 53-00-01, 747-400SF SRM 53-00-01 or 747-400LCF SRM

53-00-01, or install a full-length repair in Zone 1 in accordance with

Boeing Service Bulletin 747-53-2721, or repair the wear damage and

install rub strips in the affected areas in accordance with Boeing Service

Bulletin 747-53-2721.

{2} Install rub strips at all locations in accordance with Boeing Service

Bulletin 747-53-2721.

2) Option 2 - Non-blend repair:

Do one of the following to repair the wear damage:

a) Repair the wear damage in accordance with 747-100/200/300 SRM

53-30-03, 747-400 SRM 53-00-01, 747-SP SRM 53-39-01, 747-400F SRM

53-00-01, 747-400SF SRM 53-00-01 or 747-400LCF SRM 53-00-01.

b) Install a full-length repair in Zone 1 in accordance with Boeing Service

Bulletin 747-53-2721.

c) Repair the wear damage and install rub strips in the affected areas in

accordance with Boeing Service Bulletin 747-53-2721.

(d) If countersinking after blending would result in a knife edge condition (i.e. countersink

depth greater than 2/3 of the existing skin thickness), do not increase the countersink

depth. Repair in accordance with PART 2.

(2) FOR WEAR IN SECTION 48 (AFT OF STA 2360) (Zone 2 - Zone 6):

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

40 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
(a) If the head of any fastener in the affected area is worn beyond 0.002 inch deep (not

including paint and primer), replace the fastener in accordance with PART 2.

(b) If depth of wear in fuselage skin has exceeded the rework limits given in

747-100/200/300 SRM 53-30-01, 747-SP SRM 53-31-00, 747-400 SRM 53-00-01,

747-400F SRM 53-00-01, 747-400SF SRM 53-00-01, or 747-400LCF SRM 53-00-01,

do the following:

1) Do one of the following:

a) Repair the skin panel in accordance with 747-100/200/300 SRM 53-30-03,

747-400 SRM 53-00-01, 747-SP SRM 53-39-01, 747-400F SRM 53-00-01,

747-400SF SRM 53-00-01 or 747-400LCF SRM 53-00-01.

b) Install a full-length repair in Zone 1 in accordance with Boeing Service

Bulletin 747-53-2721.

c) Install rub strips in the affected areas in accordance with Boeing Service

Bulletin 747-53-2721.

2) Install rub strips at all locations in accordance with Boeing Service Bulletin

747-53-2721.

(c) If depth of wear in fuselage skin is within the rework limits given in 747-100/200/300

SRM 53-30-01, 747-SP SRM 53-31-00, 747-400 SRM 53-00-01, 747-400F SRM

53-00-01, 747-400SF SRM 53-00-01, or 747-400LCF SRM 53-00-01, do one of the

following options:

1) Option 1 - Blend repair:

Do the following:

NOTE: Depending on the extent and location of the wear, it might not be

possible to accomplish a blend repair and comply with the rework limits

given in the applicable SRM. If the rework limits in the applicable SRM

are exceeded, more repair work will be necessary. Refer to Paragraph

3.B., Work Instructions PART 1 step 2.a.(1)(c)1)b).

a) Repair the skin panel using the blend method in accordance with

747-100/200/300 SRM 53-30-01, Figure 1, Flagnote D, 747-400 SRM

53-00-01, Allowable Damage 1, Flagnote F, 747-SP SRM 53-31-00, Figure

1, Flagnote F, 747-400F SRM 53-00-01, Allowable Damage 1, Flagnote F,

747-400SF SRM 53-00-01, Allowable Damage 1, Flagnote F, or 747-400LCF

SRM 53-00-01, Allowable Damage 1, Flagnote F.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

41 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
NOTE: 1. Observe minimum distance of cleanout boundary from

fastener holes as stated in the SRM.

2. Based on the original nominal design skin thickness, for

any rework the total depth of material removed from the

skin must not exceed the "MAXIMUM ALLOWABLE

REWORK DEPTH" given in the applicable SRM.

3. It is recommended to record the maximum blend depth

after blend repair so that the next repeat interval can be

determined.

4. The maximum blend depth after blend repair is the depth

of the blend repair at the location where the blend depth

is largest. The blend depth is the total depth of material

removed from the skin, based on the original skin

thickness.

b) After doing the blend repair, if the blend depth is not within the rework limits

given in 747-100/200/300 SRM 53-30-01, 747-SP SRM 53-31-00, 747-400

SRM 53-00-01, 747-400F SRM 53-00-01, 747-400SF SRM 53-00-01, or

747-400LCF SRM 53-00-01, do the following:

{1} Repair the skin panel in accordance with 747-100/200/300 SRM

53-30-03, 747-400 SRM 53-00-01, 747-SP SRM 53-39-01, 747-400F

SRM 53-00-01, 747-400SF SRM 53-00-01 or 747-400LCF SRM

53-00-01 or install a full-length repair in the affected zone in accordance

with Boeing Service Bulletin 747-53-2721 or repair the wear damage

and install rub strips in the affected areas in accordance with Boeing

Service Bulletin 747-53-2721.

{2} Install rub strips at all locations in accordance with Boeing Service

Bulletin 747-53-2721.

2) Option 2 - Non-blend repair:

Do one of the following to repair the wear damage:

a) Repair the wear damage in accordance with 747-100/200/300 SRM

53-30-03, 747-400 SRM 53-00-01, 747-SP SRM 53-39-01, 747-400F SRM

53-00-01, 747-400SF SRM 53-00-01 or 747-400LCF SRM 53-00-01.

b) Install a full-length repair in the affected zone in accordance with Boeing

Service Bulletin 747-53-2721.

c) Repair the wear damage and install rub strips in the affected areas in

accordance with Boeing Service Bulletin 747-53-2721.

(3) If cracks are found, do the following:

(a) Do one of the following to repair the crack:

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

42 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
1) Repair the skin in accordance with 747-100/200/300 SRM 53-30-03, 747-400

SRM 53-00-01, 747-SP SRM 53-39-01, 747-400F SRM 53-00-01, 747-400SF

SRM 53-00-01, or 747-400LCF SRM 53-00-01

2) Install a full-length repair in the affected skin Zone in accordance with Boeing

Service Bulletin 747-53-2721.

3) Repair the wear damage and install rub strips in the affected areas in accordance

with Boeing Service Bulletin 747-53-2721.

(b) Install rub strips at all locations in accordance with Boeing Service Bulletin

747-53-2721.

(4) Apply BMS 10-86 Teflon filled coating, in accordance with FIGURE 4, over the repair, in

areas where there is no Teflon filled coating and in areas where existing Teflon filled

coating is not intact.

(a) If Teflon filled coating exists and is intact, do not apply another coat.

(b) If Teflon filled coating exists and is not intact, do one of the following to repair the

coating:

1) Option 1 (Boeing recommends): Remove all of the existing Teflon filled coating

apply new Teflon filled coating in accordance with FIGURE 4.

2) Option 2: Remove the existing Teflon filled coating that is not intact and apply

new Teflon filled coating in accordance with FIGURE 4, but only to the following

area:

– Length from 2 inches forward to 2 inches aft of where the existing Teflon

filled coating was removed.

– Width in accordance with FIGURE 4.

b. If no wear or crack is found, apply BMS 10-86 Teflon filled coating in accordance with FIGURE

4.

(1) If Teflon filled coating exists and is intact, do not apply another coat.

(2) If Teflon filled coating exists and is not intact, do one of the following to repair the coating:

(a) Option 1 (Boeing recommends): Remove all of the existing Teflon filled coating apply

new Teflon filled coating in accordance with FIGURE 4.

(b) Option 2: Remove the existing Teflon filled coating that is not intact and apply new

Teflon filled coating in accordance with FIGURE 4, but only to the following area:

– Length from 2 inches forward to 2 inches aft of where the existing Teflon filled

coating was removed.

– Width in accordance with FIGURE 4.

3. Optional: Do PART 3 - ECONOMIC BASED ADDITIONAL INSPECTIONS AND PROCEDURES

(OPERATOR OPTION)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

43 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
4. Clean the skin within five inches of the vertical stabilizer seals to remove hydraulic fluid and other

dirt and debris. Refer to SOPM 20-30-03 as an accepted procedure.

5. Restore access. Refer to FIGURE 2 as an accepted procedure if necessary.

6. Put the airplane back to a serviceable condition.

7. Repeat inspections at times given in Paragraph 1.E., Compliance. As an alternative to repeated

inspections, install CRES rub strips on the affected skin panels in accordance with 747-53-2721.

PART 2 - REPAIR OF FASTENERS WITH HEAD WEAR

1. If the head of any fastener in the affected area is worn beyond 0.002 inch deep (not including paint

and primer), do the following:

a. Remove the fastener.

b. If necessary, clean up skin damage. Blendout repairs in the skin cannot exceed the limits

given in 747-100/200/300 SRM 53-30-01, 747-SP SRM 53-31-00, 747-400 SRM 53-00-01,

747-400F SRM 53-00-01, or 747-400SF SRM 53-00-01, or 747-400LCF SRM 53-00-01.

c. Do not deepen the countersink that exists. Install a countersink repair washer in accordance

with 747-100/200/300 SRM 51-30-08, 747-SP SRM 51-30-08, 747-400 SRM 51-40-08,

747-400F SRM 51-40-08, 747-400SF SRM 51-40-08, or 747-400LCF SRM 51-40-08.

d. Install a new, protruding shear head fastener, made from A286 CRES or titanium, the same

size as was removed. The fastener can be first or second oversize in diameter, as necessary.

Install the fastener wet with BMS 5-95 sealant. Refer to the applicable SRM for acceptable

fastener type and hole sizes.

NOTE: Examples of acceptable A286 CRES fasteners that can be installed are BACB30FM(

)AK( ), BACB30FP( )AK( ), and BACB30KK( )AK( ). Example of acceptable titanium

fasteners that can be installed are BACB30MY( )K( ) and BACB30VT( )K( ).

PART 3 - ECONOMIC BASED ADDITIONAL INSPECTIONS AND PROCEDURES (OPERATOR

OPTION)

1. If wear was found in the fuselage skin at the vertical stabilizer seal interface, or if the seal is

degraded, Boeing recommends replacing the seals:

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

44 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
a. To replace the seals between STA 2288 and STA 2416:

Remove the existing seal from the forward vertical stabilizer seal panel assembly and install

a new seal on the forward vertical stabilizer seal panel assembly.

b. To replace the seals between STA 2521 and STA 2628:

Punch 0.218 - 0.229 inch diameter holes in a new seal at each applicable fastener location.

Use the existing structure or the removed seal as a template for fastener locations. Install the

new seal when restoring access in accordance with FIGURE 2.

2. Do a detailed inspection of the skin for softening or blistering of the finish within 5 inches of the

vertical stabilizer seals. If any softening or blistering is found, do the following:

a. Remove all finish within 5 inches of the affected area.

b. Restore finish. Refer to SOPM 20-41-02 as an accepted procedure.

c. If Teflon filled coating was removed, do one of the following to repair the coating:

(1) Option 1 (Boeing recommends): Remove all of the existing Teflon filled coating apply

new Teflon filled coating in accordance with FIGURE 4.

(2) Option 2: Remove the existing Teflon filled coating that is not intact and apply new Teflon

filled coating in accordance with FIGURE 4, but only to the following area:

– Length from 2 inches forward to 2 inches aft of where the existing Teflon filled coating

was removed.

– Width in accordance with FIGURE 4.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3: October 17, 2011 747-53A2478

45 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
FIGURE 1: LOGIC DIAGRAM

(SHEET 1 OF 1)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3 October 17, 2011 747-53A2478

46 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
FIGURE 2: ACCESS / RESTORATION

(SHEET 1 OF 2)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3 October 17, 2011 747-53A2478

47 of 52

BOEING SERVICE BULLETIN 747-53A2478

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 REFERENCE QTY NOTES

Access Panel Number

322CL (left side only)

1 Remove / Keep Access Panel AMM 55-30-10 1

Access Panel Number

322BL (left side only)

2 Remove / Keep Access Panel AMM 55-30-10 1

Access Panel Number

324AL (left side only)

3 Remove / Keep Access Panel AMM 55-30-10 1

Seal Panel Number

322AL (left side) and

322AR (right side)

Forward Vertical AMM 55-30-10 1

Stabilizer Seal

Panel Assembly

4 Remove / Keep

Seal attaches directly to

structure

Aft Vertical Stabiliz- - 1

er Seal

5 Remove / Keep

STEP TASK NAME REFERENCE QTY NOTES

Seal attaches directly to

structure

Aft Vertical Stabiliz- - 1

er Seal

6 Install / Kept

Seal Panel Number

322AL (left side) and

322AR (right side)

Forward Vertical AMM 55-30-10 1

Stabilizer Seal

Panel Assembly

7 Install / Kept

Access Panel Number

324AL (left side only)

8 Install / Kept Access Panel AMM 55-30-10 1

Access Panel Number

322BL (left side only)

9 Install / Kept Access Panel AMM 55-30-10 1

Access Panel Number

322CL (left side only)

10 Install / Kept Access Panel AMM 55-30-10 1

FIGURE 2: ACCESS / RESTORATION

(SHEET 2 OF 2)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3 October 17, 2011 747-53A2478

48 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
FIGURE 3: FUSELAGE SKIN INSPECTION

(SHEET 1 OF 2)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3 October 17, 2011 747-53A2478

49 of 52

BOEING SERVICE BULLETIN 747-53A2478

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

Detailed inspection.

(a)

1 Inspect Fuselage Skin - -

Surface HFEC, in

blended areas of

skin forward of STA

2360 only. (b)

2 Inspect Fuselage Skin - -

(a) Do a detailed inspection of the fuselage skin for cracks and wear at the interface of the vertical stabilizer

seal and fuselage skin.

(b) In any blended area forward of STA 2360 without external reinforcement, do surface HFEC inspections

for cracks in accordance with 747 NDT Part 6, 51-00-00, Figure 4 or 23. Inspect for potential cracks in

both the vertical and horizontal directions. Also do surface HFEC inspections for cracks around all fastener

heads in any blended area forward of STA 2360 in accordance with 747 NDT Part 6, 51-00-00, Figure 4

or 23.

FIGURE 3: FUSELAGE SKIN INSPECTION

(SHEET 2 OF 2)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3 October 17, 2011 747-53A2478

50 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT
FIGURE 4: FUSELAGE SKIN REWORK

(SHEET 1 OF 2)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3 October 17, 2011 747-53A2478

51 of 52

BOEING SERVICE BULLETIN 747-53A2478

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 Apply Primer - - (a) (b) (c)

BMS 10-86 Type I or - - (b) (c) (d)

Type II Teflon filled

coating

2 Apply

(a) Use one of the following primers; BMS 10-79 Type III, BMS 10-79 Type II or BMS 10-11 Type I.

(b) Apply to an area of the length of each vertical stabilizer seal and a width including approximately two

inches on both sides of the seal contact area.

(c) Refer to AMM 51-24-04.

(d) Apply BMS 10-86 Teflon filled coating with a minimum thickness of 0.005 inch. Refer to SOPM 20-44-01

as an accepted procedure.

FIGURE 4: FUSELAGE SKIN REWORK

(SHEET 2 OF 2)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: February 07, 2002

Revision 3 October 17, 2011 747-53A2478

52 of 52

BOEING SERVICE BULLETIN 747-53A2478

ALERT ALERT