December 18, 1991

Revision 2: October 30, 2008 747-53A2367

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 1 of 103

ALERT ALERT

Commercial

Airplane

Group 747

ALERT ALERT

Service Bulletin

Number: 747-53A2367

Date: December 18, 1991

Revision 2: October 30, 2008

ATA System: 5331

SUBJECT: FUSELAGE - Skin - Body Skin Lap Joint Inspections Based On Fatigue Test Results

BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET

Copyright © 1991 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Unpublished Work - All Rights Reserved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, 707, 717, 727, 737, 747, 757, 767, 777, BBJ, BOEING BUSINESS JET, DC-8, DC-9, DC-10, MD-10, 

MD-11, MD-80, MD-90, the Boeing logo and the Boeing livery are among the trademarks owned by Boeing or 

its subsidiaries. No intellectual property license (express or implied) is granted in connection with this document 

or otherwise.
 BLANK PAGE

December 18, 1991

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ALERT ALERT

BLANK PAGE
 Table of Contents

December 18, 1991

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ALERT ALERT

Table of Contents

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

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

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

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

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

2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

B. Concurrent Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

C. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

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

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

H. Weight and Balance Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

1. Existing Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

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

3. Installation Drawings Used in the Preparation of this Service Bulletin: . . . . . . . . . . 35

K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

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

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

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

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

C. Parts Necessary For Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

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

2. Parts and Materials Supplied by the Operator: . . . . . . . . . . . . . . . . . . . . . . 37

3. Parts Modified and Reidentified: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

4. Parts Removed and Not Replaced: . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

D. Parts Necessary to Change Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

F. Special Tooling Necessary to do this Service Bulletin . . . . . . . . . . . . . . . . . . . . . 37

3. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

B. WORK INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

FIGURE 1: THIS FIGURE IS DELETED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

FIGURE 2: SECTION 41 LAP JOINT INSPECTION - GROUP 1, 3 AND 7 AIRPLANES . . . . . . . . 45

FIGURE 3: SECTION 41 LAP JOINT INSPECTION - GROUP 2, 4, 8 AND 9 AIRPLANES . . . . . . 48

FIGURE 4: SECTION 41 LAP JOINT INSPECTION - GROUP 5, 6 AND 10 AIRPLANES . . . . . . . 52

FIGURE 5: SECTION 42 LAP JOINT INSPECTION - GROUP 1, 2, 4, 5, 7, 8, 9 AND 10 AIRPLANES 56

FIGURE 6: SECTION 42 LAP JOINT INSPECTION - GROUP 3 AND 6 AIRPLANES . . . . . . . . . 58

FIGURE 7: SECTION 46 LAP JOINT INSPECTION - GROUP 1, 2, 4, 5, 7, 8, 9 AND 10 AIRPLANES 60

FIGURE 8: SECTION 46 LAP JOINT INSPECTION - GROUP 3 AND 6 AIRPLANES . . . . . . . . . 62

FIGURE 9: SECTION 41 LAP JOINT INSPECTION - GROUP 1, 3 AND 7 AIRPLANES . . . . . . . . 64

FIGURE 10: SECTION 41 LAP JOINT INSPECTION - GROUP 2, 4, 8 AND 9 AIRPLANES . . . . . . 68

FIGURE 11: SECTION 41 LAP JOINT INSPECTION - GROUP 5, 6, AND 10 . . . . . . . . . . . . . 72
 Table of Contents

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FIGURE 12: SECTION 42 LAP JOINT INSPECTION - GROUP 1, 2, 4, 5, 7, 8 AND 9 AIRPLANES . . 75

FIGURE 13: SECTION 42 - LAP JOINT INSPECTION - GROUP 10 . . . . . . . . . . . . . . . . . . 77

FIGURE 14: SECTION 46 - LAP JOINT INSPECTION - GROUPS 1, 2, 4 AND 5 . . . . . . . . . . . . 79

FIGURE 15: SECTION 41, STRINGER 6 - LAP JOINT MODIFICATION - GROUP 1, 2, 4, 5, 7, 8, 9 AND

10 AIRPLANES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

FIGURE 16: SECTION 41, STRINGER 23 - LAP JOINT MODIFICATION - GROUP 1, 2, 4, 5, 7, 8, 9 AND

10 AIRPLANES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

FIGURE 17: SECTION 42, 44 AND 46 LAP JOINT INSPECTION - GROUP 3 AND 6 AIRPLANES . . 87

FIGURE 18: SECTION 41, STRINGER 44 - LAP JOINT MODIFICATION - GROUP 1, 2, 4, 5, 7, 8, 9 AND

10 AIRPLANES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

FIGURE 19: SECTION 42, STRINGER 44 - LAP JOINT MODIFICATION - GROUP 1, 2, 4, 5, 7, 8, 9 AND

10 AIRPLANES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94

FIGURE 20: SECTION 46 LAP JOINT INSPECTION - GROUP 7, 8, 9 AIRPLANES . . . . . . . . . 96

FIGURE 21: SECTION 46 - LAP JOINT INSPECTION - GROUP 10 AIRPLANES . . . . . . . . . . 101
December 18, 1991

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ALERT ALERT

Commercial

Airplane

Group 747

ALERT ALERT

Service Bulletin

Number: 747-53A2367 Revision Transmittal Sheet

Date: December 18, 1991

Revision 2: October 30, 2008

ATA System: 5331

SUBJECT: FUSELAGE - Skin - Body Skin Lap Joint Inspections Based On Fatigue Test Results

This revision includes all pages of the service bulletin.

COMPLIANCE INFORMATION RELATED TO THIS REVISION

More work is necessary on airplanes changed as given in the initial release or revision 1 of this service bulletin. 

Lap joint inspections are necessary over an expanded inspection area. Lap joint modification is necessary in 

specific areas at the time given in Paragraph 1.E., Compliance.

No airplanes have been added to the service bulletin effectivity as a result of this revision.

REASON FOR REVISION

This revision is sent to expand the lap joint inspection area shown in this service bulletin and add a lap joint 

modification for specific areas.

Changes to this service bulletin include:

— References to the increased inspections and modification are added to Summary Section and Paragraph 

1.D., Description.

— Reference to Jacking and Support recommendations are added to Paragraph 1.D., Description. 

— Paragraph 1.E., Compliance - Existing Compliance information to inspect for cracks is added in new Table 

1. New Compliance information is added to Table 3 to accomplish the modification. Reference to FAA 

Airworthiness Directives (AD) 94-12-04 and 2004-07-22 R1 are added.

— Paragraph 1.G., Manpower - New tables are added for the increased inspections and structural 

modifications.

— Paragraph 1.H., Weight and Balance - reference to determine Weight and Balance changes as a result of 

inspection findings paragraph added. 

— Paragraph 1.J.2., Data Supplied with this Service Bulletin - New table added to list modification drawing 

numbers to be supplied. 

— Paragraph 3.A., General Information - Reference to Compliance thresholds and jacking/support 

recommendations are added.

— Paragraph 3.B., Work Instructions - Reference to Figures 9 to 14, 17, 20 and 21 for increased inspections 

and reference to Figures 15, 16, 18 and 19 for instructions to accomplish the lap joint modification are 

added.

— Figure 1 - Logic diagram is deleted. The information previously in Figure 1 is moved to Paragraph 1.E., 

Compliance.

— Figures 9 to 14, 20 and 21 are added to show increased inspection locations.
 

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— Figures 15, 16, 18 and 19 are added to show modification locations. 

— Figure 17 is added to show increased inspection locations for 747 SP airplanes.

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

paragraph for changes.

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

of important changes.

Pages with no vertical lines have no important changes.

REVISION HISTORY

Initial Release: December 18, 1991

Revision 1: January 27, 1994

Revision 2: October 30, 2008
December 18, 1991

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ALERT ALERT

Commercial

Airplane

Group 747

ALERT ALERT

Service Bulletin

Number: 747-53A2367 Summary

Date: December 18, 1991

Revision 2: October 30, 2008

ATA System: 5331

SUBJECT: FUSELAGE - Skin - Body Skin Lap Joint Inspections Based On Fatigue Test Results

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

Based on a structural review of the 747 airplane, incorporation of the inspection shown in this service bulletin is 

recommended on the 747 airplanes shown in this service bulletin.This service bulletin gives data for the 

inspection and repair of certain 747 airplane body skin longitudinal lap joints. These inspections and repairs are 

necessary for safe operation of 747 airplanes past the design goal for economic usage.

Boeing has completed extended pressure fatigue tests on two 747 fuselage test articles. These tests have 

identified areas of the body lap joints where fatigue cracks can occur. Inspection and repair of these areas is 

necessary for safe operation of 747 airplanes past the design goal for economic usage.

The inspections in this service bulletin will make sure that fatigue cracks in the body lap joints shown are found 

and repaired before they become critical. Skin cracks not detected prior to reaching critical crack length may 

result in in-flight depressurization of the airplane and the inability to withstand current regulatory fail-safe loads.

Subsequent to the previous release of this bulletin a review of all lap joints was accomplished for the affected 

airplanes and it was determined that all lap joints with upper skin thickness of 0.090 inches or less should be 

inspected at the times given in paragraph 1.E., Compliance. 

In addition, subsequent to the previous release of this service bulletin a review of all bulletins which recommend 

repeat inspections was performed to determine if the inspections were appropriate on aging airplanes. This 

review indicated that certain lap joints where the skin thickness is less than or equal to 0.071 inches should be 

modified at the times given in Paragraph 1.E., Compliance on airplanes, line numbers 201 through 810.
 

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ACTION

Do external surface High Frequency Eddy Current (HFEC) inspections of certain lap joints for cracks. These 

lap joints are in Section 41, Section 42, Section 44 and Section 46. If no cracks are found, do the inspection 

again at the time shown in this service bulletin. If cracks are found, remove the fastener in the cracked hole and 

sufficient adjacent fasteners and do open hole HFEC inspections to find the crack length. Repair as shown in 

the structural repair manual before any more flights.

Do the lap joint modification in Section 41 and Section 42 at the time given in Paragraph 1.E., Compliance. 

EFFECTIVITY

All 747-100, 747-100B, 747-100B SUD, 747-200B, 747-300, 747SP, and 747SR series airplanes.

COMPLIANCE

Refer to Service Bulletin Paragraph 1.E. for Compliance information. 

Federal Aviation Administration (FAA) Airworthiness Directives 94-12-04 and 2004-07-22 R1 are related to this 

service bulletin.

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

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

bulletin mandatory.

INDUSTRY SUPPORT INFORMATION

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

depends upon whether you ever filed a warranty claim with Boeing on this service bulletin.

MANPOWER

Refer to Paragraph 1.G., Manpower. 

MATERIAL INFORMATION

None.
 

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FAIRING

S-46

WING-TO-BODY

AFT

S-40

FORWARD WING-TO-BODY FAIRING

(TYPICAL)

LAP JOINT S-34

S-45

S-34

S-39

S-44

HFEC INSPECT SKIN LAP JOINTS FOR

CRACKS IN UPPER FASTENER ROWS

ACCOMPLISH A STRUCTURAL

MODIFICATION ON SPECIFIED LAP

SECTION 41 JOINTS AT STRINGERS 6,23 AND 44

(TYPICAL)

STRINGER

(TYPICAL)

STRINGER

44 AND 46

SECTION 42,

ROW

UPPER

CRACK UPPER SKIN

FASTENER

(TYPICAL)

FLUSH HEAD

(TYPICAL)

PROTRUDING

HEAD FASTENER

GROUP 1,2,4,5 AND 7 THROUGH 10

AIRPLANES SHOWN.

GROUP 3 AND 6 AIRPLANES

SIMILAR.

LEFT SIDE SIMILAR

RIGHT SIDE SHOWN

140

STA

SECTIONS 41 AND 42

520

S-6

S-0

STA

S-23

S-19

S-14

S-23

S-19

STA

1000

LAP JOINT

(TYPICAL)

STA SECTION 46

S-4

1480

STA

2360

S-12

S-12

SECTION 44

1479023
 

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BLANK PAGE
December 18, 1991

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ALERT ALERT

Commercial

Airplane

Group 747

ALERT ALERT

Service Bulletin

Number: 747-53A2367

Date: December 18, 1991

Revision 2: October 30, 2008

ATA System: 5331

SUBJECT: FUSELAGE - Skin - Body Skin Lap Joint Inspections Based On Fatigue Test Results

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.

This service bulletin is for the airplanes shown below.

GROUP CONFIGURATION DESCRIPTION

1 - 747 Airplane line numbers 201 through 603 

except 747SP airplanes, nose cargo door 

airplanes and airplanes changed to the 

Stretched Upper Deck (SUD) configuration.

2 - 747 Airplane line numbers 201 through 603 

changed to the SUD configuration.

3 - 747SP Airplane line numbers 201 through 603.

4 - 747 Airplane line numbers 604 through 628 

except nose cargo door airplanes.

5 - 747-200B and 747-300 airplanes line number 

629 through 810.

6 - 747SP Airplane line number 676.

7 - 747 Airplane line numbers 201 through 603 

same as Group 1 except these airplanes have 

had a Boeing side cargo door modification.
 

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Airplane models:

747-100 747-100B 747-100B SUD 747-200B

747-300 747SP 747SR

IDENTIFICATION BY CUSTOMER, CUSTOMER CODE, GROUP AND VARIABLE NUMBER

AAR A/C ENG. SALES & LEASING (AFD)

1 RB681–RB682

AEROLINEAS ARGENTINAS (ARG)

1 RD122–RD127

AFRICA UNITED HOLDING CO. (UHD)

1 RB010 RD513

AFX (AXL)

7 RD201

AIR ATLANTA ICELANDIC (AID)

1 RD141 RD414 RS211 RS222

RS233 RS235 RS237

4 RD456

5 RB411–RB413 RB421 RD755 RD774

RS332–RS333

7 RD647–RD648 RD771

AIR CANADA (ACN)

7 RA749–RA750 RD531

AIR CHINA (BEJ)

5 RD783

9 RD782

AIR FRANCE (AFA)

5 RD659 RS751–RS752

7 RD655 RD657

8 RD721–RD722

8 - 747 Airplane line numbers 201 through 603 

same as Group 2 except these airplanes have 

had a Boeing side cargo door modification.

9 - 747 Airplane line numbers 604 through 628 

same as Group 4 except these airplanes have 

had a Boeing side cargo door modification.

10 - 747 Airplane line numbers 629, 635, 637, 650, 

666-667, 673, 675, 679, 683, 685, 713, 750 and 

810.

GROUP CONFIGURATION DESCRIPTION
 

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AIR INDIA (AIN)

1 RA729 RA731

5 RS781–RS782

AIR PULLMANTUR (PUL)

5 RD791 RS331

AIR UNIVERSAL (UVL)

5 RD231–RD232 RD291–RD292 RD775

7 RD649

AMERICAN AIRLINES (AAL)

1 RA266

ATLAS AIR (TLS)

1 RB684

10 RS722

7 RD361–RD366 RD641 RD691–RD692 RD753

9 RD754

AVIATION EXPOSURE MANAGEMENT (EXU)

1 RD131–RD132 RD143

BAHRAIN ROYAL FLIGHT (BHR)

3 RG009

6 RH102

BOEING AIRCRAFT HOLDING CO. (BHC)

1 RB691 RB693 RD181 RD451–RD452

RD454

7 RD453

BOEING WICHITA MOD CENTER (WMC)

1 RD455

C.I.T. LEASING CORPORATION (TCI)

1 RB011 RD047

CAPITAL ASSET MANAGEMENT (CPG)

1 RD053

CARGAIR (CGL)

7 RD203

CARGO 360, INC. (CGN)

10 RS786

CATHAY PACIFIC AIRWAYS (CAT)

7 RD358 RD581–RD583

CORSAIR (COR)

4 RS239–RS240
 

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DRAGONAIR (DRG)

10 RS741 RS743 RS771

DUBAI AIR WING (DAW)

7 RD622

EL AL ISRAEL AIRLINES (ELA)

7 RD442

EUROPEAN AVIATION AIR CHARTER (EUL)

1 RD135–RD138

5 RD311

EVERGREEN INTERNATIONAL A/L (EVR)

1 RB604 RB607 RD004 RD041–RD043

9 RD772–RD773

EXPORT RESTRICTED AIRPLANES (YWV)

1 RB711

3 RG101–RG104 RG141–RG142 RG171

7 RD681–RD682

FINOVA (GRB)

5 RS761

GA TELESIS, LLC (GTG)

3 RG163

GENERIC CUSTOMER/SUPPLIER (XXX)

2 RD382

GLOBAL AIR LEASING (GAO)

3 RG164

GLOBAL PEACE INITIATIVE (GPI)

3 RG174

GRACE CATHEDRAL INC. (GCI)

3 RG193

GUGGENHEIM AVIATION PARTNERS (GPR)

1 RB692 RB697

IBERIA AIRLINES (IBE)

1 RD431–RD435

INTERNATIONAL AIR LEASES (IAL)

1 RB006

IRAQI AIRWAYS (IRQ)

3 RG095 RG172
 

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JAL INTERNATIONAL (JAL)

1 RD222 RS251–RS253

10 RD227

4 RS254

5 RS256 RS259 RS265–RS267

7 RD055

JET AERO HOLDINGS (JHD)

3 RG122

JOHNSON SPACE CENTER (ZBR)

1 RB601

KABO AIR (KAB)

1 RA316 RB008 RD121

KALITTA AIR (KAC)

1 RA545–RA548 RB605 RD054 RD083

RD221 RD223–RD224

7 RD082 RD225 RD571 RD621

RD623

KUWAIT AIRWAYS (KUW)

7 RD202 RD204

L-3 COMMUNICATIONS (LCS)

1 RD352

LOGISTIC AIR, INC. (LGA)

1 RB722–RB723

MK AIRLINES (MKA)

7 RD441 RD781

NASA (NAS)

3 RG091

NEA HOLDINGS, INC. (NEA)

1 RD045–RD046

NIPPON CARGO AIRLINES (NCA)

1 RB696

10 RD233–RD235

7 RD461

NORTHWEST AIRLINES (NWA)

1 RD056–RD057 RD241–RD243 RD251–RD255 RD257–RD259

10 RD301–RD302

5 RD261–RD262

OCEAN AIRLINES (OCE)

7 RD658
 

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OMAN ROYAL FLIGHT (RFO)

3 RG161

OMEGA AIR HOLDINGS (OMC)

7 RD142 RD144 RD412

9 RS721

ORIENT THAI AIRLINES (OTH)

1 RA528 RA543–RA544 RD516

4 RS292

5 RS001–RS002 RS257

7 RS712

PAKISTAN INT'L AIRLINES (PIA)

1 RD104

4 RS301

5 RS302–RS306

7 RD701–RD702

PHUKET AIRLINES (PHK)

1 RD421–RD424

2 RD381

4 RS238 RS241

7 RS711

8 RD605

POLAR AIR CARGO (PAO)

7 RD752

PRATT & WHITNEY ENGINE SERVICE (PWE)

3 RG213

QANTAS (QAN)

4 RS272–RS273

5 RS274–RS276

ROYAL AIR MAROC (RAM)

7 RD671

S583 (583)

10 RD166–RD167

SATAIR (SAI)

8 RD606

SAUDI ARABIAN AIRLINES (SVA)

1 RB741–RB746 RB748

3 RH121

4 RS311–RS315

5 RS316–RS320
 

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SAUDI ROYAL FLIGHT (SRF)

1 RS699

3 RH101 RH122

SKY EXPRESS S.A. (SXS)

7 RD592

SOUTH AFRICAN AIRWAYS (SAA)

1 RS212 RS232 RS236

3 RG123 RG125

SOUTHERN AIR (SOF)

1 RB695 RD272

2 RD383

5 RD792

7 RD411 RD642–RD643

8 RD601–RD602 RD607

SUO1 (UO1)

1 RB013–RB016

SURINAM AIRWAYS (SUR)

5 RS713

TAAG (ANGOLA AIRLINES) (ANG)

5 RS703 RS742

TESIS AVIATION ENTERPRISE (TEV)

1 RA784

TRADEWINDS AIRLINES (TWN)

1 RA726 RD052 RD426

7 RD646

TRANSAERO AIRLINES (TRX)

1 RD226 RD356 RD471–RD475 RS271

5 RS255 RS258 RS263 RS268

TRANSATLANTIC INTL AIRLINES (TIB)

3 RG173

UNICAL AVIATION (UNL)

5 RS341–RS342

UPS (UPS)

1 RD051 RD058–RD059

7 RD593

VIRGIN ATLANTIC AIRWAYS (VAA)

1 RD357
 

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VOLGA-DNEPR AIRLINES (VDA)

10 RS762

7 RD751

WINGS WORLD WIDE (WWW)

3 RG221–RG222

WORLDWIDE AIRCRAFT HOLDING CO. (WAH)

3 RG008

YEMENIA (YEM)

3 RG162

YONA (IOP)

3 RG191

IDENTIFICATION BY VARIABLE NUMBER

Variable Group

RA260–RA266 1

RA313–RA318 1

RA415–RA418 1

RA528 1

RA541–RA548 1

RA725–RA731 1

RA744–RA745 1

RA749–RA750 7

RA783–RA784 1

RB006–RB016 1

RB411–RB413 5

RB421 5

RB601–RB607 1

RB681–RB697 1

RB711 1

RB721–RB723 1

RB741–RB748 1

RD003–RD004 1

RD021–RD022 1

RD041–RD054 1

RD055 7

RD056–RD059 1

RD071–RD072 1

RD081 1

RD082 7
 

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RD083 1

RD091–RD092 1

RD101–RD104 1

RD121–RD127 1

RD131–RD141 1

RD142 7

RD143 1

RD144 7

RD166–RD167 10

RD171–RD172 1

RD181–RD183 1

RD201–RD204 7

RD221–RD224 1

RD225 7

RD226 1

RD227 10

RD231–RD232 5

RD233–RD235 10

RD241–RD243 1

RD251–RD259 1

RD260–RD262 5

RD271–RD272 1

RD291–RD292 5

RD301–RD302 10

RD311 5

RD351–RD357 1

RD358 7

RD361–RD366 7

RD381–RD383 2

RD411–RD412 7

RD413–RD414 1

RD421–RD426 1

RD431–RD435 1

RD441–RD442 7

RD451–RD452 1

RD453 7

RD454–RD455 1

RD456 4

RD461 7

Variable Group
 

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RD471–RD475 1

RD513–RD519 1

RD531–RD533 7

RD551 7

RD561 7

RD571 7

RD581–RD583 7

RD591–RD593 7

RD601–RD607 8

RD621–RD623 7

RD641–RD649 7

RD651–RD658 7

RD659 5

RD661 7

RD671 7

RD681–RD682 7

RD691–RD692 7

RD701–RD702 7

RD721–RD722 8

RD741–RD742 7

RD751–RD753 7

RD754 9

RD755 5

RD761 7

RD771 7

RD772–RD773 9

RD774–RD775 5

RD781 7

RD782 9

RD783 5

RD791–RD792 5

RE001 1

RG001–RG009 3

RG091 3

RG095 3

RG101–RG104 3

RG121–RG126 3

RG141–RG142 3

RG161–RG164 3

Variable Group
 

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RG171–RG174 3

RG191–RG193 3

RG211–RG213 3

RG221–RG222 3

RH101 3

RH102 6

RH111–RH112 3

RH121–RH122 3

RS001–RS002 5

RS201 1

RS211–RS212 1

RS221–RS222 1

RS231–RS237 1

RS238–RS241 4

RS251–RS253 1

RS254 4

RS255–RS259 5

RS263 5

RS265–RS268 5

RS271 1

RS272–RS273 4

RS274–RS276 5

RS291–RS292 4

RS301 4

RS302–RS306 5

RS311–RS315 4

RS316–RS320 5

RS331–RS333 5

RS341–RS342 5

RS699 1

RS701–RS702 7

RS703 5

RS711–RS712 7

RS713 5

RS721 9

RS722 10

RS731–RS732 5

RS741 10

RS742 5

Variable Group
 

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2. Spares Affected

None.

B. Concurrent Requirements

None.

C. Reason

As a result of the FAA-sponsored Aging Fleet Conference, a 747 Structures Working Group with 

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

modifications and inspections and recommend selected service bulletins for incorporation on aging 

airplanes. The 747 Structures Working Group has determined that the inspections shown in this 

service bulletin should be accomplished on the airplanes shown in this service bulletin at or before the 

accumulation of 22,000 flight-cycles. This service bulletin gives data for the inspection and repair of 

certain 747 airplane body skin longitudinal lap joints. These inspections and repairs are necessary for 

safe operation of 747 airplanes past the design goal for economic usage.

Boeing has completed extended pressure fatigue tests on two 747 fuselage test articles. These tests 

have identified areas of the body lap joints where fatigue cracks can occur. Inspection and repair of 

these areas is necessary for safe operation of 747 airplanes past the design goal for economic usage.

The inspections in this service bulletin will make sure that fatigue cracks in the body lap joints shown 

are found and repaired before they become critical. Skin cracks not detected prior to reaching critical 

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

regulatory fail-safe loads. Revision 1 is sent to recommend that the inspections shown in this service 

bulletin be accomplished on the 747 airplanes shown in this service bulletin at or before the 

accumulation of 22,000 flight-cycles. As a result of the FAA-sponsored Aging Fleet Conference, a 747 

Structures Working Group with Airline and Boeing members and FAA observers was formed to review 

structural service bulletin modifications and inspections and recommend selected service bulletins for 

incorporation on aging airplanes. The 747 Structures Working Group has determined that the 

inspections shown in this service bulletin should be accomplished on the airplanes shown in this 

service bulletin at or before the accumulation of 22,000 flight-cycles. Revision 1 is also sent to add 

references to FAA Notice of Proposed Rule Making, FAA Docket Number 93-NM-182-AD. The data 

given in Notice of Status Change 747-53-2367 NSC 1 and NSC 2 is included in Revision 1. NSC 1 

was sent to give operators data about when to do inspections at stringer S-6 after Service Bulletin 747-

53-2272 has been installed. NSC 2 was sent to tell operators that airplanes with a nose cargo door 

should not be listed in Paragraph I.A., Effectivity. 

RS743 10

RS751–RS752 5

RS761 5

RS762 10

RS771 10

RS781–RS782 5

RS786 10

Variable Group
 

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Subsequent to the previous release of this bulletin a review of all lap joints was accomplished for the 

affected airplanes and it was determined that all lap joints with upper skin thickness of 0.090 inches 

or less should be inspected at the times given in paragraph 1.E., Compliance. 

In addition, subsequent to the previous release of this service bulletin a review of all bulletins which 

recommend repeat inspections was performed to determine if the inspections were appropriate on 

aging airplanes. This review indicated that certain lap joints where the skin thickness is less than or 

equal to 0.071 inches should be modified at the times given in Paragraph 1.E., Compliance on 

airplanes, line numbers 201 through 810.

Revision 1 was sent to recommend that the inspections shown in this service bulletin be accomplished 

on the 747 airplanes shown in this service bulletin at or before the accumulation of 22,000 flightcycles. As a result of the FAA-sponsored Aging Fleet Conference, a 747 Structures Working Group 

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

modifications and inspections and recommend selected service bulletins for incorporation on aging 

airplanes. The 747 Structures Working Group has determined that the inspections shown in this 

service bulletin should be accomplished on the airplanes shown in this service bulletin at or before the 

accumulation of 22,000 flight-cycles. Revision 1 was also sent to add references to FAA Notice of 

Proposed Rule Making, FAA Docket Number 93-NM-182-AD. The data given in Notice of Status 

Change 747-53-2367 NSC 1 and NSC 2 is included in Revision 1. NSC 1 was sent to give operators 

data about when to do inspections at stringer S-6 after Service Bulletin 747-53-2272 has been 

installed. NSC 2 was sent to tell operators that airplanes with a nose cargo door should not be listed 

in Paragraph I.A., Effectivity. 

Revision 2 is sent to expand the lap joint inspection area shown in this service bulletin and add a lap 

joint modification for specific areas.

Changes to this service bulletin include:-

— References to the increased inspections and modification are added to Summary Section and 

Paragraph 1.D., Description.

— Paragraph 1.E., Compliance - Existing Compliance information to inspect for cracks is added in 

new Table 1. New Compliance information is added to Table 2 to accomplish the modification. 

Reference to FAA Airworthiness Directives (AD) 94-12-04 and 2004-07-22 R1 are added.

— Paragraph 1.G., Manpower - New tables are added for the increased inspections and structural 

modifications.

— Paragraph 1.H., Weight and Balance - reference to determine Weight and Balance changes as 

a result of inspection findings paragraph added. 

— Paragraph 1.J.2., Data Supplied with this Service Bulletin - New table added to list modification 

drawing numbers to be supplied. 

— Paragraph 3.A., General Information - Reference to Compliance thresholds are added.

— Paragraph 3.B., Work Instructions - Reference to Figures 9 to 14, 17, 20 and 21 for increased 

inspections and reference to Figures 15, 16, 18 and 19 for instructions to accomplish the lap joint 

modification are added.

— Figure 1 - Logic diagram is deleted. The information previously in Figure 1 is moved to Paragraph 

1.E., Compliance.

— Figures 9 to 14, 20 and 21 are added to show increased inspection locations.

— Figures 15, 16, 18 and 19 are added to show modification locations. 

— Figure 17 is added to show increased inspection locations for 747 SP airplanes.
 

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D. Description

Based on a structural review of the 747 airplane, it is recommended that the inspections shown in this 

service bulletin be accomplished on the 747 airplanes shown in this service bulletin at or before the 

accumulation of 22,000 flight-cycles.

Do external surface High Frequency Eddy Current (HFEC) inspections of certain lap joints for cracks. 

These lap joints are in Section 41, Section 42, Section 44 and Section 46. If no cracks are found, do 

the inspection again at the time shown in this service bulletin. If cracks are found, remove the fastener 

in the cracked hole and sufficient adjacent fasteners and do open hole HFEC inspections to find the 

crack length. Repair as shown in the structural repair manual before any more flights.

Do the lap joint modification in Section 41 and Section 42 at the time given in paragraph 1.E., 

Compliance. 

Airplane effectivity is divided in ten groups. This is because of the size of the inspection areas and 

work done by other service bulletins, as shown below:

Group 1 - All 747 airplanes line number 201 through 603, except 747SP airplanes, nose cargo door 

airplanes, and airplanes changed to the Stretched Upper Deck (SUD) configuration as shown in 

Master Change MC 42360-( ).

Group 2 - All 747 airplanes line number 201 through 603 changed to the Stretched Upper Deck (SUD) 

configuration as shown in Master Change MC 42360-( ).

Group 3 - All 747SP airplanes line number 201 through 603.

Group 4 - All 747 airplanes line number 604 through 628, except nose cargo door airplanes.

Group 5 - All 747-200 and 747-300 airplanes line number 629 through 810, except nose cargo door 

airplanes.

Group 6 - 747SP airplane line number 676.

Group 7 - 747 airplanes line number 201 through 603 same as Group 1 except these airplanes have 

had a Boeing side cargo door modification. 

Group 8 - 747 airplanes line number 201 through 603 same as Group 2 except these airplanes have 

had a Boeing side cargo door modification. 

Group 9 - 747 airplanes line number 604 through 628 same as Group 4 except these airplanes have 

had a Boeing side cargo door modification. 

Group 10 - 747 airplanes line numbers 629, 635, 637, 650, 666-667, 673, 675, 679, 683, 685, 713, 

750 and 810. 

On Group 1 and 3 airplanes, the body lap joint at stringer S-6 is changed by other service bulletins. 

From STA 340 to 400, the lap joint was changed by Service Bulletins 747-53-2253 or 747-53-2272. 

From STA 400 to 520, the lap joint was changed by Service Bulletin 747-53A2303. Service Bulletins 

747-53-2253 and 747-53A2303 make it necessary to do continued inspections of the S-6 lap joint from 

STA 340 to STA 520.
 

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On Group 2 and 4 airplanes, the body lap joint at stringer S-6 is changed by other service bulletins. 

From STA 340 to 400, an external doubler is installed over the lap joint by Service Bulletin 747-53-

2272. From STA 400 to 520, the lap joint was changed by Service Bulletin 747-53A2303. Service 

Bulletin 747-53A2303 makes it necessary to do continued inspections of the S-6 lap joint from STA 

400 to STA 520. As recommended by the 747 Aging Fleet Structures Working Group, start to do 

inspections as shown in the Accomplishment Instructions at or before the accumulation of 22,000 

flight-cycles.

This service bulletin is listed in Boeing Document D6-35999, "Aging Airplane Service Bulletin 

Structural Modification and Inspection Program, Model 747."

Revision 1 - No more work is necessary on airplanes inspected by the initial release of this service 

bulletin as a result of Revision 1. Continue to do inspections as shown in this service bulletin.

Revision 2 - More work is necessary on airplanes changed as given in the initial release or revision 1 

of this service bulletin. Lap joint inspections are necessary over an expanded inspection area. Lap 

joint modification is necessary in specific areas at the time given in Paragraph 1.E., Compliance. 
 

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NOTE:

1. Inspection and maintenance alternatives are shown in a diagram in Section 3., 

ACCOMPLISHMENT INSTRUCTIONS.

2. If the external skin panel of an affected lap joint has been replaced, start to do 

inspections of that lap joint 22, 000 full pressure flight-cycles after the skin was replaced. 

3. If an external doubler has been installed along the affected lap joint: 

— If the external doubler were installed by either Service Bulletin 747-53-2253 or 747-

53-2272 at S-6, then no additional inspection or modification are required by this 

Service Bulletin in the area of the external doubler.

— If the external doubler were installed by either Service Bulletin 747-53-2305 at S44, then no additional inspection or modification are required by this Service 

Bulletin in the area of the external doubler. 

— If the external doubler were installed by SRM 747 53-30-03, Figures 11, 13, 14, 16, 

17, 20, 22, 23, 25, 26, 29, 31, 32, 34, 48, and the external doubler is 40 inches or 

less, then no additional inspections are required by this Service Bulletin. 

— If the external doubler installed by SRM 747-53-03 Figures 11, 13, 14, 16, 17, 20, 

22, 23, 25, 26, 29, 31, 32, 34, 48, is longer than 40 inches, inspect per paragraph 

1.E. Compliance, Table 2. 

— Otherwise contact Boeing with details of the external doubler so that the 

modification and its inspection can be modified.

— If an external doubler was installed per SB 747-53-2286 then no additional 

inspections are required by this Service Bulletin prior to modification of S-44 in 

Section 42.

4. For the purposes of this service bulletin, do not count flight-cycles with a cabin pressure 

differential of 2.0 psi or less. 

5. For 747SR airplanes only, multiply the thresholds and inspection intervals in this service 

bulletin by the 1.2 adjustment factor. This is based on continued mixed operation at 

lower cabin pressure differentials.

6. If the damaged area is more than the limits specified in the structural repair manual, write 

to Boeing for repair instructions. To help Boeing send a reply, give the limits and location 

of the damage. When possible, send sketches and photographs. If the damage includes 

corrosion, send data on the length, width and largest depth of clean up. 

SEND TO:

BOEING COMMERCIAL AIRPLANE GROUP

ATTENTION: MANAGER, AIRLINE SUPPORT 

7. At all lap joint areas not covered by the lap joint modification given in this service bulletin, 

a lap joint modification must be installed at 35,000 total flight cycles. Boeing is not 

planning to provide engineering drawings for the modification. 

8. Because of the extent of the work required to accomplish the modification in this Service 

Bulletin, jacking and support of the airplane will be necessary. Boeing can provide a 

jacking plan for incorporation of the bulletin. To have Boeing assist in developing 

jacking/support recommendations the following is required: 

— A list of structures related Service Bulletins to be incorporated.

— The exact airplane configuration including weight and center of gravity.

— Whether the following will be installed or removed: landing gear, flaps, engines, 
 

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pylons and interiors.

— The airplane identification (line number or variable number).

— List the lap joints to be modified and lap the joints that require repair (if possible).

— Provide the planned incorporation date for the bulletin modification. Provide 

adequate time for Boeing to develop the necessary data and for any required 

contacts or agreements to be developed. 

E. Compliance

Federal Aviation Administration (FAA) Airworthiness Directives 94-12-04 and 2004-07-22 R1 are 

related to this service bulletin.

To comply with the service bulletin recommendations and possible future FAA AD requirements, 

operators must complete the actions included in Table 1, Table 2, and Table 3.

Table 1 - Lap Joint Inspection

Condition Action Compliance Time

Repeat Interval 

(Not to Exceed)

All Airplanes Do the Area 1 eddy 

current inspections 

for cracks in the 

skin as given in 

work instructions 

Paragraph 3.B.1., 

Part 1.

Before 

22,000 

total flight 

cycles. (f)

Within 3,000 

flight cycles from 

the last HFEC 

inspection of the 

area as given in 

the SSID. (c)

Within 1,000 

flight cycles 

from the date 

on the original 

issue of this 

service 

bulletin.

-

All Airplanes Do the Area 2 eddy 

current inspections 

for cracks in the 

skin as given in 

work instructions 

Paragraph 3.B.1., 

Part 2.

Before 

22,000 

total flight 

cycles. (f)

Within 3,000 

flight cycles from 

the last HFEC 

inspection of the 

area as given in 

the SSID. (c)

Within 1,000 

flight cycles 

from the date 

on Revision 2 

of this service 

bulletin.

-

Any crack found. Repair the lap joint 

as given in work 

instructions 

Paragraph 3.B.1.f. 

or 3.B.2.i.

Before further flight. -

Areas where no 

crack is found.

Repeat the 

inspection for 

cracks as given in 

work instructions 

Paragraph 3.B.1., 

Part 1 and 3.B.2., 

Part 2.

Within 3,000 flight-cycles from the last 

inspection, or within 1,500 flight-cycles from 

the last inspection for airplanes with more 

than 30,000 total flight-cycles.

3,000 flight-cycles 

or 1,500 flight 

cycles for airplanes 

with more than 

30,000 total flight 

cycles. (a) (b) (g)
 

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Areas where a lap 

joint repair was 

installed as given 

in work 

instructions 

Paragraphs 

3.B.1.f. or 3.B.2.i., 

and the repair 

doubler(s) is 

greater than or 

equal to 40 inches 

long. (d)

Accomplish internal 

HFEC inspections 

for cracks as given 

in D6-36181, 

"Repair 

Assessment 

Guidelines - Model 

747."

Within 15,000 flight-cycles from the time the 

repair was installed.

3,000 flight cycles 

or 1,500 flight 

cycles for airplanes 

with more than 

30,000 total flight 

cycles. (a) (b) (e)

(a) For laps joints specified in work instructions Paragraph 3.B.3., Part 3 on airplanes with more than 30,000 

total flight cycles, reduce the inspection interval to 1,500 flight cycles until the lap joint modification given in 

Paragraph 3.B.3., Part 3 is accomplished.

(b) Accomplishment of a lap joint modification as given in work instructions Paragraph 3.B.3., Part 3 

terminates the repeat inspections as given in work instructions Paragraphs 3.B.1, Part 1 and 3.B.2, Part 2 

for the length of the lap joint that is modified.

(c) The Supplemental Structural Inspection Document (SSID) D6-35022, Revision G for SSI’s F-25G, F-25H, 

and F-25J provides inspection options for the subject lap joints. Only the HFEC inspection will allow this 

compliance time. 

(d) Refer to D6-36181, "Repair Assessment Guidelines - Model 747" for inspection requirements (including 

inspection method and compliance time) of areas where a lap joint repair was installed as given in work 

instructions Paragraph 3.B.1.f. or 3.B.2.i., and the repair doubler is less than 40 inches long. The 

inspections given in this table are no longer necessary for those areas.

(e) At tearstraps and frame shear ties, where skin is not inspectable for less than 4 inches, HFEC inspection 

is not required.

(f) For Group 2, 4, 8, and 9 airplanes, if the airplane is not affected by Service Bulletin 747-53-2253, start to 

do inspections of the lap joints in Section 41 at stringer S-6 within 10,000 flight-cycles after doublers are 

installed as given in Service Bulletin 747-53-2272.

(g) For Group 7, 8, and 9 airplanes, inspections of the lap joints in Section 46 at stringer 4 left, between STA 

1720 and STA 1740, and between STA 1960 and STA 1980 must be repeated at intervals not to exceed 

1,500 flight-cycles. This inspection is for cracks in the upper skin under an external doubler.

Table 1 - Lap Joint Inspection

Condition Action Compliance Time

Repeat Interval 

(Not to Exceed)
 

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NOTE: Additional work is required for continued operation beyond 15,000 flight-cycles after the

modification, contact Boeing for instructions.

The Federal Aviation Administration (FAA) will possibly release another Airworthiness Directive 

related to this service bulletin. The Airworthiness Directive will make the compliance tasks and times 

given in this service bulletin mandatory.

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 FAA. In addition, The Manager of the FAA Seattle ACO 

approves the accomplishment of the applicable inspection, repair, and modification procedures of this 

service bulletin as an alternative method of compliance (AMOC) to the corresponding inspection and 

repair requirements of paragraphs (h), (i), and (j) of FAA AD 2004-07-22 R1 for SSI F-25G, F-25H, 

and F-25I of Supplemental Structural Inspection Document (SSID) D6-35022, Revision G, dated 

December 2000. This AMOC only applies to the areas inspected as given in this service bulletin. 

When this service bulletin specifies contacting Boeing for repair instructions, the repair instructions 

must be in accordance with FAA-approved procedures as required by paragraph (j) of the AD. All 

provisions of AD 2004-07-22 R1 that are not specifically referenced in the preceding statement, 

including the initial inspection threshold per paragraph (i) of AD 2004-07-22 R1, remain fully applicable 

and must be complied with.

Table 2 - Lap Joint Modification

Condition Action Compliance Time (Whichever Occurs Later)

All airplanes. Do the lap joint 

modification as given 

in Work Instructions 

Paragraph 3.B.3., 

Part 3.(b)

Before 30,000 total flight 

cycles.

Within 3,000 flight cycles 

from the release date of 

Revision 2 of this service 

bulletin, whichever is 

earlier.(a)

(a) For lap joints specified in PART 3 on airplanes with more than 30,000 total flight cycles, the 

inspection interval must be reduced to 1,500 flight cycles until the lap joint modification is 

accomplished as given in Paragraph 3.B., Work Instructions, PART 3. 

(b) Accomplishment of a lap joint modification as given in Paragraph 3.B.3., Part 3 terminates the 

repeat inspections as given in work instructions Paragraph 3.B.1, Part 1 and 3.B.2, Part 2 for the 

length of the lap joint that is modified. Furthermore, no lap joint modification instructions are 

included in this service bulletin for Group 3 and Group 6 airplanes. Contact Boeing for 

instructions.
 

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

The Manager of the FAA Seattle ACO also approves the accomplishment of the applicable inspection, 

repair, and modification procedures of this service bulletin as an AMOC to the corresponding 

inspection, repair, and modification requirements of paragraphs (a), (b), and (c) of AD 94-12-04. This 

AMOC only applies to the areas inspected as given in this service bulletin. When this service bulletin 

specifies contacting Boeing for repair instructions, the repair instructions must be in accordance with 

paragraph (d) of AD 94-12-04. All provisions of AD 94-12-04 that are not specifically referenced in the 

preceding statement remain fully applicable and must be complied with.

G. Manpower

The data below shows an estimate of the man-hours necessary to do this inspection for each airplane. 

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

man-hour data if necessary. The estimate does not include lost time. These are some examples of 

lost time:

— Time to adjust to the workplace

— Time to schedule the work

— Time to examine the work

— Time to cure the materials

— Time to make the parts

— Time to find the tools.

Group 1, 7: Lap Joint Inspections - Area 1

Task Number of 

Persons

Man-Hours Elapsed Time 

(Hours)

Section 41 Lap Joints

Inspect 2 6 3

Section 42 Lap Joints

Inspect 1 3.5 3.5

Section 46 Lap Joints

Inspect 1 3.25 3.25

TOTAL 12.75 9.75 (a)

(a) Elapsed time will be less if Sections 41, 42 and 46 are inspected at the same time. 

Group 2, 4, 8-9: Lap Joint Inspections - Area 1

Task Number of 

Persons

Man-Hours Elapsed Time 

(Hours)

Section 41 Lap Joints

Inspect 2 6.5 3.25

Section 42 Lap Joints

Inspect 1 3.5 3.5

Section 46 Lap Joints

Inspect 1 3.25 3.25

TOTAL 13.25 10 (a)

(a) Elapsed time will be less if Sections 41, 42 and 46 are inspected at the same time. 
 

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ALERT ALERT

Group 3: Lap Joint Inspections - Area 1

Task Number of 

Persons

Man-Hours Elapsed Time 

(Hours)

Section 41 Lap Joints

Inspect 2 6 3

Section 42 Lap Joints

Inspect 1 2 2

Section 46 Lap Joints

Inspect 1 3.5 3.5

TOTAL 11.5 8.5 (a)

(a) Elapsed time will be less if Sections 41, 42 and 46 are inspected at the same time. 

Group 5, 10: Lap Joint Inspections - Area 1

Task Number of 

Persons

Man-Hours Elapsed Time 

(Hours)

Section 41 Lap Joints

Inspect 2 7 3.5

Section 42 Lap Joints

Inspect 1 3.5 3.5

Section 46 Lap Joints

Inspect 1 3.25 3.25

TOTAL 13.75 10.25 (a)

(a) Elapsed time will be less if Sections 41, 42 and 46 are inspected at the same time. 

Group 6: Lap Joint Inspections - Area 1

Task Number of 

Persons

Man-Hours Elapsed Time 

(Hours)

Section 41 Lap Joints

Inspect 2 7 3.5

Section 42 Lap Joints

Inspect 1 2 2

Section 46 Lap Joints

Inspect 1 3.5 3.5

TOTAL 12.5 9 (a)

(a) Elapsed time will be less if Sections 41, 42 and 46 are inspected at the same time. 

Group 1: Lap Joint Inspections - Expanded Area 2

Task Number of 

Persons

Man-Hours Elapsed Time 

(Hours)

Section 41 Lap Joints

Inspect 4 114 28.5

Section 42 Lap Joints
 

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Inspect 4 190 47.5

Section 44 Lap Joints

Inspect 2 15 7.5

Section 46 Lap Joints

Inspect 4 158 39.5

TOTAL 477 123 (a)

(a) Elapsed time will be less if Sections 41, 42, 44 and 46 are inspected at the same time. 

Group 2, 4: Group 2, 4, 8, 9: Lap Joint Inspections - Expanded Area 2

Task Number of 

Persons

Man-Hours Elapsed Time 

(Hours)

Section 41 Lap Joints

Inspect 4 114 28.5

Section 42 Lap Joints

Inspect 4 190 47.5

Section 44 Lap Joints

Inspect 2 15 7.5

Section 46 Lap Joints

Inspect 4 158 39.5

TOTAL 477 123 (a)

(a) Elapsed time will be less if Sections 41, 42, 44 and 46 are inspected at the same time. 

Group 3: Lap Joint Inspections - Expanded Area 2

Task Number of 

Persons

Man-Hours Elapsed Time 

(Hours)

Section 41 Lap Joints

Inspect 4 114 28.5

Section 42 Lap Joints

Inspect 4 114 28.5

Section 44 Lap Joints

Inspect 4 58 14.5

Section 46 Lap Joints

Inspect 4 150 37.5

TOTAL 436 109 (a)

(a) Elapsed time will be less if Sections 41, 42, 44 and 46 are inspected at the same time. 

Group 1: Lap Joint Inspections - Expanded Area 2

Task Number of 

Persons

Man-Hours Elapsed Time 

(Hours)
 

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Group 5: Group 5, 10: Lap Joint Inspections - Expanded Area 2

Task Number of 

Persons

Man-Hours Elapsed Time 

(Hours)

Section 41 Lap Joints

Inspect 2 114 28.5

Section 42 Lap Joints

Inspect 4 190 47.5

Section 44 Lap Joints

Inspect 2 15 7.5

Section 46 Lap Joints

Inspect 4 158 39.5

TOTAL 477 123 (a)

(a) Elapsed time will be less if Sections 41, 42, 44 and 46 are inspected at the same time. 

Group 6: Lap Joint Inspections - Expanded Area 2

Task Number of 

Persons

Man-Hours Elapsed Time 

(Hours)

Section 41 Lap Joints

Inspect 4 114 28.5

Section 42 Lap Joints

Inspect 4 114 28.5

Section 44 Lap Joints

Inspect 4 58 14.5

Section 46 Lap Joints

Inspect 4 150 37.5

TOTAL 436 109 (a)

(a) Elapsed time will be less if Sections 41, 42, 44 and 46 are inspected at the same time. 

Group 1-2, 4-5: Lap Joint Modification

Task Number of 

Persons

Man-Hours Elapsed Time 

(Hours)

Section 41 Lap Joints

Modification 12 144 12

Section 42 Lap Joints

Modification 4 27 6.75

TOTAL 171 18.75 (a)

(a) Elapsed time will be less if Sections 41 and 42 are modified at the same time. 
 

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ALERT ALERT

H. Weight and Balance Changes

Installation of lap joint repairs and modifications as outlined in 747-100/-200/-300 SRM 53-30-03 

where the skin thickness at the upper row of fasteners is less than or equal to 0.071 inches will affect 

the weight and balance of the airplane. Determination of these changes is necessary, once the 

configuration of the lap joint repairs and modifications are defined.

I. Electrical Load Data

Not changed.

J. References

1. Existing Data:

a. 747-100/-200/-300 Structural Repair Manual (SRM) Subject 53-30-03. 

b. 747SP Structural Repair Manual (SRM) Subject 53-30-03.

c. 747 Nondestructive Test Manual (NDT), Part 6, Subject 51-00-00, 53-30-00, 53-30-02, 53-

30-03, 53-30-06.

d. Boeing Service Bulletins 747-53-2253, "Fuselage - Nose Section - Station 340 to 400 

Stringer 6 Inspection and Modification," 747-53-2272, "Fuselage - Nose Section 41 Body 

Frame Structure Replacement and Reinforcement," 747-53A2303, "Fuselage - Nose 

Section - Station 400 to 520 Stringer 6 Lap Splice Inspection, Repair and Modification" and 

747-53-2386, "Skin Inspection, Repair and Modification at Body Station 570 - Equipment 

Cooling Outlet.

e. Master Change MC 42360-( ).

f. Boeing Document D6-35999, "Aging Airplane Service Bulletin Structural Modification 

Program, Model 747".

g. FAA Airworthiness Directives (AD) 94-12-04 and 2004-07-22 R1.

h. Supplemental Structural Inspection Document D6-35022.

2. Data supplied with this Service Bulletin:

a. Drawings:

Drawing Number Title Sheet DCN ADCN

691U1049 747 Section 41, S-6 Skin 

Reinforcement - STA 400 - 520. 

1- -

691U1050 747 Section 41, S-23 Skin 

Reinforcement - STA 220 - 400. 

1- -

691U1051 747 Section 41, S-44 Skin 

Reinforcement - STA 420 - 520. 

1- -

691U1052 747 Section 42, S-44 Skin 

Reinforcement - STA 520 - 741. 

1- -
 

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ALERT ALERT

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

None.

K. Publications Affected

L. Interchangeability and Intermixability of Parts

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

Publication Chapter-Section

747 Structural Repair Manual 53-30-03, Figure 64, Stringer 6 - BS400 - 

BS520 (747-100 and -200 LHS and 747-

300 LHS and RHS. 

53-30-03, Figure 65, Stringer 23, BS220 - 

BS400.

53-30-03, Figure 66, Stringer 44, BS420 -

BS520. 

53-30-03, Figure 67, Stringer 44, BS520-

BS741.1.

747 Weight and Balance Manual
 

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ALERT ALERT

BLANK PAGE
 

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ALERT ALERT

2. MATERIAL INFORMATION

A. Material - Price and Availability

None.

B. Industry Support Information

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

airplanes depends upon whether you ever filed a warranty claim with Boeing on this service bulletin.

C. Parts Necessary For Each Airplane

1. Kits/Parts:

None.

2. Parts and Materials Supplied by the Operator:

Materials and fasteners are required to do the lap splice modifications. Operators should refer to 

modification drawings and the SRM for specific raw material and fastener requirements. The 

drawing numbers and SRM references are in the accomplishment instructions and figures. 

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 I.J., References, can be 

necessary. Examine operator tool supply to make sure all necessary tools are available.
 

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ALERT ALERT

BLANK PAGE
 

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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. These work instructions refer to procedures included on 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 "as given 

in" are included in the instruction, the procedure in the Boeing document must be used.

4. If the external skin panel of an affected lap joint has been replaced, start to do 

inspections of that lap joint 22,000 full pressure flight cycles after the skin was replaced.

5. On Group 2 and 4 airplanes, external doublers are installed at S-6 as shown in Service 

Bulletin 747-53-2272. Start to do inspections of the lap joint at stringer S-6 10,000 flight 

cycles after the doublers are installed. 

6. If an external doubler has been installed along the affected lap joint: 

— If the external doubler were installed by either Service Bulletin 747-53-2253 or 747-

53-2272 at S-6, then no additional inspection or modification are required by this 

Service Bulletin in the area of the external doubler.

— If the external doubler were installed by either Service Bulletin 747-53-2305 at S44, then no additional inspection or modification are required by this Service 

Bulletin in the area of the external doubler. 

— If the external doubler were installed by SRM 747 53-30-03, Figures 11, 13, 14, 16, 

17, 20, 22, 23, 25, 26, 28, 29, 31, 32, 34, 48, and the external doubler is 40 inches 

or less, then no additional inspections are required by this Service Bulletin. 

— If the external doubler installed by SRM 747 53-30-03, Figures 11, 13, 14, 16, 17, 

20, 22, 23, 25, 26, 28, 29, 31, 32, 34, 48, is longer than 40 inches, inspect per 

paragraph 1.E. Compliance, Table 2. 

— Otherwise contact Boeing with details of the external doubler so that the 

modification and its inspection can be modified.

— If an external doubler was installed per SB 747-53-2286 then no additional 

inspections are required by this Service Bulletin prior to modification of S-44 in 

Section 42.

7. A heavy continuous line is used to indicate the lap joint areas that should be inspected 

as shown in Figures 2 to 14, 17, 20, 21 and lap joint areas that should be modified as 

shown in Figures 15, 16, 18 and 19. 

8. Refer to Paragraph 1.E., Compliance for thresholds and repeat inspection intervals.
 

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ALERT ALERT

9. Because of the extent of the work required to accomplish the modification in this Service 

Bulletin, jacking and support of the airplane will be necessary. Boeing can provide a 

jacking plan for incorporation of the bulletin. To have Boeing assist in developing 

jacking/support recommendations the following is required: 

— A list of structures related Service Bulletins to be incorporated.

— The exact airplane configuration including weight and center of gravity.

— Whether the following will be installed or removed: landing gear, flaps, engines, 

pylons and interiors.

— The airplane identification (line number or variable number).

— List the lap joints to be modified and lap the joints that require repair (if possible).

— Provide the planned incorporation date for the bulletin modification. Provide 

adequate time for Boeing to develop the necessary data and for any required 

contacts or agreements to be developed. 

B. WORK INSTRUCTIONS

1. PART 1 - LAP JOINT INITIAL INSPECTION - AREA 1. 

a. Group 1, 7: Inspect lap joints as follows.

(1) Do an inspection of the Section 41 lap joints left and right side as given in Figure 2.

(2) Do an inspection of the Section 42 lap joints left and right side as given in Figure 5.

(3) Do an inspection of the Section 46 lap joints left and right side as given in Figure 7.

b. Group 2, 4, 8-9: Inspect lap joints as follows.

(1) Do an inspection of the Section 41 lap joints left and right side as given in Figure 3.

(2) Do an inspection of the Section 42 lap joints left and right side as given in Figure 5.

(3) Do an inspection of the Section 46 lap joints left and right side as given in Figure 7.

c. Group 3: Inspect lap joints as follows.

(1) Do an inspection of the Section 41 lap joints left and right side as given in Figure 2.

(2) Do an inspection of the Section 42 lap joints left and right side as given in Figure 6.

(3) Do an inspection of the Section 46 lap joints left and right side as given in Figure 8.

d. Group 5, 10: Inspect lap joints as follows.

(1) Do an inspection of the Section 41 lap joints left and right side as given in Figure 4.

(2) Do an inspection of the Section 42 lap joints left and right side as given in Figure 5.

(3) Do an inspection of the Section 46 lap joints left and right side as given in Figure 7.

e. Group 6: Inspect lap joints as follows.

(1) Do an inspection of the Section 41 lap joints left and right side as given in Figure 4.
 

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ALERT ALERT

(2) Do an inspection of the Section 42 lap joints left and right side as given in Figure 6.

(3) Do an inspection of the Section 46 lap joints left and right side as given in Figure 8.

f. If cracks are found, repair the cracks as follows:

(1) Remove the fastener from the hole that indicates a crack.

(2) Remove all fasteners in the upper fastener row of the lap joint within 10 inches forward 

and aft of the crack location, and do open-hole High Frequency Eddy Current (HFEC) 

inspections of the fastener holes to find cracks. Use 747 NDT Manual, Part 6, Subject 

51-00-00, Figure 1, Figure 11, or Figure 16. If cracking is found, continue performing 

open-hole HFEC inspection of the fastener holes within 10 inches forward and aft of 

the crack location for cracks. 

(3) Repair the cracks as shown in 747 Structural Repair Manual Subject 53-30-03, Figures 

11, 13, 14, 16, 17, 19, 20, 22, 23, 25, 26, 28, 29, 31, 32, 34 and 48. If cracks are larger 

than the limits shown in the structural repair manual, ask Boeing for repair data.

(4) Do the Part 2 inspections at the time given in Paragraph 1.E., Compliance.

g. If no cracks are found, do the Part 2 Inspections at the time given in Paragraph 1.E. 

Compliance.

h. Put the airplane back to a serviceable condition.

2. PART 2 - LAP JOINT INSPECTIONS - EXPANDED INSPECTION - AREA 2

a. Group 1: Inspect lap joints as follows.

(1) Do an inspection of the Section 41 lap joints left and right side as given in Figure 9.

NOTE: At stringer S-6 between STA 400 (aft of crew door) and STA 520 if cracks are

found at this area contact Boeing. If no cracks are found, refer to 691U1049

sheet 1. 

(2) Do an inspection of the Section 42 lap joints left and right side as given in Figure 12.

(3) Do an inspection of the Section 46 lap joints left and right side as given in Figure 14.

b. Group 2, 4: Inspect lap joints as follows.

(1) Do an inspection of the Section 41 lap joints left and right side as given in Figure 10.

(2) Do an inspection of the Section 42 lap joints left and right side as given in Figure 12.

(3) Do an inspection of the Section 46 lap joints left and right side as given in Figure 14.

c. Group 3: Inspect lap joints as follows.

(1) Do an inspection of the Section 41 lap joints left and right side as given in Figure 9.
 

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ALERT ALERT

(2) Do an inspection of the Section 42, 44 and 46 lap joints left and right side as given in 

Figure 17.

d. Group 5: Inspect lap joints as follows.

(1) Do an inspection of the Section 41 lap joints left and right side as given in Figure 11.

(2) Do an inspection of the Section 42 lap joints left and right side as given in Figure 12.

(3) Do an inspection of the Section 46 lap joints left and right side as given in Figure 14.

e. Group 6: Inspect lap joints as follows.

(1) Do an inspection of the Section 41 lap joints left and right side as given in Figure 11.

(2) Do an inspection of the Section 42, 44 and 46 lap joints left and right side as given in 

Figure 17.

f. Group 7: Inspect lap joints as follows.

(1) Do an inspection of the Section 41 lap joints left and right side as given in Figure 9.

NOTE: At stringer S-6 between STA 400 (aft of crew door) and STA 520 if cracks are

found at this area contact Boeing. If no cracks are found, refer to 691U1049

sheet 1. 

(2) Do an inspection of the Section 42 lap joints left and right side as given in Figure 12.

(3) Do an inspection of the Section 46 lap joints left and right side as given in Figure 20.

g. Group 8-9: Inspect lap joints as follows.

(1) Do an inspection of the Section 41 lap joints left and right side as given in Figure 10.

(2) Do an inspection of the Section 42 lap joints left and right side as given in Figure 12.

(3) Do an inspection of the Section 46 lap joints left and right side as given in Figure 20.

h. Group 10: Inspect lap joints as follows.

(1) Do an inspection of the Section 41 lap joints left and right side as given in Figure 11.

(2) Do an inspection of the Section 42 lap joints left and right side as given in Figure 13.

(3) Do an inspection of the Section 46 lap joints left and right side as given in Figure 21.

i. If cracks are found, repair the cracks as follows:

(1) Remove the fastener from the hole that indicates a crack.
 

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(2) Remove all fasteners in the upper fastener row of the lap joint within 10 inches forward 

and aft of the crack location, and do open-hole High Frequency Eddy Current (HFEC) 

inspections of the fastener holes to find cracks. Use 747 NDT Manual, Part 6, Subject 

51-00-00, Figure 1, Figure 11, or Figure 16. If cracking is found, continue performing 

open-hole HFEC inspection of the fastener holes within 10 inches forward and aft of 

the crack location for cracks. 

(3) Repair the cracks as shown in 747 Structural Repair Manual Subject 53-30-03, Figure 

11, 13, 14, 16, 17, 19, 20, 22, 23, 25, 26, 28, 29, 31, 32, 34 and 48. If cracks are larger 

than the limits shown in the structural repair manual, ask Boeing for repair data.

(4) Repeat the Part 2 inspections at the time given in Paragraph 1.E., Compliance.

j. If no cracks are found, repeat the Part 2 inspections at the time given in Paragraph 1.E., 

Compliance.

k. Put the airplane back to a serviceable condition.

3. PART 3 - LAP JOINT MODIFICATION

a. Group 1-2, 4-5, 7-10: Do the Section 41, Stringer 6 lap joint modification left and right side 

as given in Figure 15.

NOTE: At stringer S-6 between STA 400 (aft of crew door) and STA 520 if cracks are found

at this area contact Boeing. 

b. Group 1-2, 4-5, 7-10: Do the Section 41, Stringer 23 lap joint modification left and right side 

as given in Figure 16.

c. Group 1-2, 4-5, 7-10: Do the Section 41, Stringer 44 lap joint modification left and right side 

as given in Figure 18.

d. Group 1-2, 4-5, 7-10: Do the Section 42, Stringer 44 lap joint modification left and right side 

as given in Figure 19. 

NOTE: If repair or modification incorporated per SB 747-53-2386, contact Boeing.

e. Group 3, 6: No lap joint modification instructions are included for Group 3 and Group 6 

airplanes. Contact Boeing if you intend to operate a Group 3 or Group 6 airplane after 

30,000 total flight cycles. 

f. Put the airplane back to a serviceable condition.
 FIGURE 1: THIS FIGURE IS DELETED

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FIGURE 1: THIS FIGURE IS DELETED

THIS FIGURE IS DELETED.

D38438

(SHEET 1 OF 1)
 FIGURE 2: SECTION 41 LAP JOINT INSPECTION - GROUP 1, 3 AND 7 AIRPLANES

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ALERT ALERT

FIGURE 2: SECTION 41 LAP JOINT INSPECTION - GROUP 1, 3 AND 7 AIRPLANES

LAP SPLICE

FOR TYPICAL

SEE DETAIL I

S-45R

S-45L

S-23L

STA 520

S-44L

S-44R

NOSE WHEEL WELL

BOTTOM VIEW

STA

140

SEE DETAIL I

FOR TYPICAL LAP SPLICE

SEE DETAIL I

FOR TYPICAL LAP SPLICE

FORWARD

ENTRY DOOR

S-14

STA

520

STA

140

TYPICAL LEFT SIDE SHOWN

RIGHT SIDE OPPOSITE

981144

(SHEET 1 OF 3)
 FIGURE 2: SECTION 41 LAP JOINT INSPECTION - GROUP 1, 3 AND 7 AIRPLANES

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ALERT ALERT

DETAIL I

LAP SPLICE (TYPICAL)

LEFT SIDE SHOWN

RIGHT SIDE OPPOSITE

CIRCUMFERENTIAL

SPLICE

INDICATES AREA TO

BE INSPECTED

LOWER SKIN PANEL

UPPER SKIN PANEL

STRINGER

CENTERLINE

FWD

UP

1

981145

(SHEET 2 OF 3)
 FIGURE 2: SECTION 41 LAP JOINT INSPECTION - GROUP 1, 3 AND 7 AIRPLANES

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ALERT ALERT

The step number shown below agree with the number shown in the circle symbol in the figure.

1. Do external surface HFEC inspections of the body longitudinal lap joints at stringers S-14, S-23, S-44, and 

S-45. Do inspections of the skin at the upper row of fasteners in the lap joints. At protruding head fastener 

locations use 747 Nondestructive Test Manual D6-7170, Part 6, Subject 51-00-00, Figure 4 or Figure 23. 

At countersunk fastener locations use 747 Nondestructive Test Manual D6-7170, Part 6, Subject 53-30-02, 

53-30-03, or 53-30-06.

NOTE: At stringer S-44 between STA 400 and STA 440, also do inspections of the skin at the upper row

of fasteners common to the internal doubler installed in production.

(SHEET 3 OF 3)
 FIGURE 3: SECTION 41 LAP JOINT INSPECTION - GROUP 2, 4, 8 AND 9 AIRPLANES

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FIGURE 3: SECTION 41 LAP JOINT INSPECTION - GROUP 2, 4, 8 AND 9 AIRPLANES

S-14L

S-6L

STA

140

DOOR OPENING

LEFT SIDE CREW

S-14L

S-6L

S-23L

S-23L

A LEFT SIDE

AIRPLANES WITH

CREW DOOR SEE DETAIL II

SEE DETAIL I

A LEFT SIDE CREW DOOR

AIRPLANES WITHOUT

340

400

STA

STA

STA

520

SEE DETAIL III

FOR TYPICAL LAP SPLICE

SEE DETAIL I

SEE DETAIL III

FOR TYPICAL LAP SPLICE

SEE DETAIL II

STA

520

340

STA

400

STA

STA

140

981148

(SHEET 1 OF 4)
 FIGURE 3: SECTION 41 LAP JOINT INSPECTION - GROUP 2, 4, 8 AND 9 AIRPLANES

December 18, 1991

Revision 2: October 30, 2008 747-53A2367

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

DETAIL I

SEE DETAIL III

FOR TYPICAL LAP SPLICE

SPLICE

FOR TYPICAL LAP

SEE DETAIL III

S-45R

S-45L

S-14R

S-6R

S-23R

BOTTOM VIEW

DETAIL II

SEE

LAP SPLICE

FOR TYPICAL

SEE DETAIL III

SEE DETAIL I

OPENING

CREW DOOR

RIGHT SIDE

140

STA

STA

340

400

STA

520

STA

STA 520

S-44L

S-44R

NOSE WHEEL WELL

STA

140

981149

(SHEET 2 OF 4)
 FIGURE 3: SECTION 41 LAP JOINT INSPECTION - GROUP 2, 4, 8 AND 9 AIRPLANES

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

DETAIL III

DETAIL II

LOWER SKIN PANEL

RIGHT SIDE OPPOSITE

LEFT SIDE SHOWN

UPPER SKIN PANEL

STRINGER

INDICATES AREA TO

BE INSPECTED

SPLICE

CENTERLINE

LAP SPLICE (TYPICAL)

CIRCUMFERENTIAL

STRINGER 6

UPPER

SKIN PANEL

LOWER

SKIN PANEL

LOWER DOUBLER

CENTERLINE

UPPER DOUBLER

RIGHT SIDE OPPOSITE

LEFT SIDE SHOWN

LAP SPLICE (TYPICAL)

CIRCUMFERENTIAL

SPLICE

FWD

UP

1

2

FWD

UP

981152

(SHEET 3 OF 4)
 FIGURE 3: SECTION 41 LAP JOINT INSPECTION - GROUP 2, 4, 8 AND 9 AIRPLANES

December 18, 1991

Revision 2: October 30, 2008 747-53A2367

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 51 of 103

BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

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

1. Do external surface HFEC inspections of the body longitudinal lap joints at stringers S-14, S-23, S-44, and 

S-45. Do inspections of the skin at the upper row of fasteners in the lap joints. At protruding head fastener 

locations use 747 Nondestructive Test Manual D6-7170, Part 6, Subject 51-00-00, Figure 4 or Figure 23. 

At countersunk fastener locations use 747 Nondestructive Test Manual D6-7170, Part 6, Subject 53-30-02, 

53-30-03, or 53-30-06.

NOTE: At stringer S-44 between STA 400 and STA 440, also do inspections of the skin at the upper row

of fasteners common to the internal doubler installed in production.

2. Do an external surface HFEC inspection of the external doubler at the fasteners common to the upper row 

of the S-6 lap joint. External doublers were installed along S-6 by Service Bulletin 747-53-2272. At 

protruding head fastener locations use 747 Nondestructive Test Manual D6-7170, Part 6, Subject 51-00-

00, Figure 4 or Figure 23. At countersunk fastener locations use 747 Nondestructive Test Manual D6-7170, 

Part 6, Subject 53-30-02, 53-30-03, or 53-30-06.

NOTE: Start to do inspections of the lap joint at stringer S-6 10,000 flight-cycles after doublers are

installed as shown in Service Bulletin 747-53-2272 if airplane is not covered by Service Bulletin

747-53-2253.

(SHEET 4 OF 4)
 FIGURE 4: SECTION 41 LAP JOINT INSPECTION - GROUP 5, 6 AND 10 AIRPLANES

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

FIGURE 4: SECTION 41 LAP JOINT INSPECTION - GROUP 5, 6 AND 10 AIRPLANES

AIRPLANES WITHOUT

CREW DOOR

A LEFT SIDE

CREW DOOR

A LEFT SIDE

AIRPLANES WITH

S-14L

S-23L

SEE DETAIL II

SEE DETAIL I

FOR TYPICAL LAP SPLICE

STA

140

S-6L

SEE DETAIL II

FOR TYPICAL LAP SPLICE

520

CREW DOOR OPENING

UPPER DECK LEFT SIDE

340

STA

STA

S-14L

S-6L

S-23L

SEE DETAIL II

FOR TYPICAL LAP SPLICE

SEE DETAIL II

FOR TYPICAL LAP SPLICE

SEE DETAIL I

STA

520

340

STA

STA

140

981153

(SHEET 1 OF 4)
 FIGURE 4: SECTION 41 LAP JOINT INSPECTION - GROUP 5, 6 AND 10 AIRPLANES

December 18, 1991

Revision 2: October 30, 2008 747-53A2367

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

S-23R

BOTTOM VIEW

SEE DETAIL I

140

STA

STA

340

520

STA

FOR TYPICAL LAP SPLICE

S-44L

S-44R

NOSE WHEEL WELL

STA

140

LAP SPLICE

FOR TYPICAL

SEE DETAIL II

SEE DETAIL II

S-6R

S-14R

LAP SPLICE

FOR TYPICAL

SEE DETAIL II

OPENING

CREW DOOR

RIGHT SIDE

S-45L

S-45R

SPLICE

SEE DETAIL II

FOR TYPICAL LAP

DETAIL I

STA

520

981155

(SHEET 2 OF 4)
 FIGURE 4: SECTION 41 LAP JOINT INSPECTION - GROUP 5, 6 AND 10 AIRPLANES

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

DETAIL II

CIRCUMFERENTIAL

SPLICE UPPER SKIN PANEL

LOWER SKIN PANEL

STRINGER

CENTERLINE

INDICATES AREA TO

BE INSPECTED

RIGHT SIDE OPPOSITE

LEFT SIDE SHOWN

LAP SPLICE (TYPICAL)

FWD

UP

1

981158

(SHEET 3 OF 4)
 FIGURE 4: SECTION 41 LAP JOINT INSPECTION - GROUP 5, 6 AND 10 AIRPLANES

December 18, 1991

Revision 2: October 30, 2008 747-53A2367

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 55 of 103

BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

The step number shown below agrees with the number shown in the circle symbol in the figure.

1. Do external surface HFEC inspections of the body longitudinal lap joints at stringers S-6, S-14, S-23, S-44, 

and S-45. Do inspections of the skin at the upper row of fasteners in the lap joints shown. At protruding 

head fastener locations use 747 Nondestructive Test Manual D6-7170, Part 6, Subject 51-00-00, Figure 4 

or Figure 23. At countersunk fastener locations use 747 Nondestructive Test Manual D6-7170, Part 6, 

Subject 53-30-02, 53-30-03, or 53-30-06.

NOTE: At stringer S-44 between STA 400 and STA 440, also do inspections of the skin at the upper row

of fasteners common to the internal doubler installed in production.

(SHEET 4 OF 4)
 FIGURE 5: SECTION 42 LAP JOINT INSPECTION - GROUP 1, 2, 4, 5, 7, 8, 9 AND 10 AIRPLANES

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

FIGURE 5: SECTION 42 LAP JOINT INSPECTION - GROUP 1, 2, 4, 5, 7, 8, 9 AND 10 AIRPLANES

RIGHT SIDE OPPOSITE

LEFT SIDE SHOWN

LAP SPLICE

FOR TYPICAL

SEE DETAIL I

DOOR NO. 2

MAIN ENTRY

S-44

S-23

1000

STA 741

520 STA

STA

981159

(SHEET 1 OF 2)
 FIGURE 5: SECTION 42 LAP JOINT INSPECTION - GROUP 1, 2, 4, 5, 7, 8, 9 AND 10 AIRPLANES

December 18, 1991

Revision 2: October 30, 2008 747-53A2367

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 57 of 103

BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

The step number shown below agrees with the number shown in the circle symbol in the figure.

1. Do external surface HFEC inspections of the body longitudinal lap joints at stringers S-23 and S-44. Do 

inspections of the skin at the upper row of fasteners in the lap joints shown. At protruding head fastener 

locations use 747 Nondestructive Test Manual D6-7170, Part 6, Subject 51-00-00, Figure 4 or Figure 23. 

At countersunk fastener locations use 747 Nondestructive Test Manual D6-7170, Part 6, Subject 53-30-02, 

53-30-03, or 53-30-06.

DETAIL I

UPPER SKIN PANEL

STRINGER

CENTERLINE

CIRCUMFERENTIAL

SPLICE

LOWER SKIN PANEL

BE INSPECTED

INDICATES AREA TO

RIGHT SIDE OPPOSITE

LEFT SIDE SHOWN

LAP SPLICE (TYPICAL)

UP

FWD

1

981160

(SHEET 2 OF 2)
 FIGURE 6: SECTION 42 LAP JOINT INSPECTION - GROUP 3 AND 6 AIRPLANES

December 18, 1991

Revision 2: October 30, 2008 747-53A2367

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

FIGURE 6: SECTION 42 LAP JOINT INSPECTION - GROUP 3 AND 6 AIRPLANES

FWD

RIGHT SIDE OPPOSITE

LEFT SIDE SHOWN

OPENING

DOOR NO. 2

MAIN ENTRY

LAP SPLICE

FOR TYPICAL

SEE DETAIL I

S-44

S-23

1000

STA

560

STA

520 STA

981112

(SHEET 1 OF 2)
 FIGURE 6: SECTION 42 LAP JOINT INSPECTION - GROUP 3 AND 6 AIRPLANES

December 18, 1991

Revision 2: October 30, 2008 747-53A2367

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 59 of 103

BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

The step number shown below agrees with the number shown in the circle symbol in the figure.

1. Do external surface HFEC inspections of the body longitudinal lap joints at stringers S-23 and S-44. Do 

inspections of the skin at the upper row of fasteners in the lap joints shown. At protruding head fastener 

locations use 747 Nondestructive Test Manual D6-7170, Part 6, Subject 51-00-00, Figure 4 or Figure 23. 

At countersunk fastener locations use 747 Nondestructive Test Manual D6-7170, Part 6, Subject 53-30-02, 

53-30-03, or 53-30-06.

DETAIL I

UPPER SKIN PANEL

INDICATES AREA TO

BE INSPECTED

LEFT SIDE SHOWN

RIGHT SIDE OPPOSITE

LAP SPLICE (TYPICAL)

LOWER SKIN PANEL

SPLICE

CIRCUMFERENTIAL

CENTERLINE

STRINGER

1

FWD

UP

981117

(SHEET 2 OF 2)
 FIGURE 7: SECTION 46 LAP JOINT INSPECTION - GROUP 1, 2, 4, 5, 7, 8, 9 AND 10 AIRPLANES

December 18, 1991

Revision 2: October 30, 2008 747-53A2367

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

FIGURE 7: SECTION 46 LAP JOINT INSPECTION - GROUP 1, 2, 4, 5, 7, 8, 9 AND 10 AIRPLANES

LEFT SIDE ONLY

1741

2180

STA

STA

1480

STA

S-46

DOOR N0. 4

MAIN ENTRY

LAP SPLICE

FOR TYPICAL

SEE DETAIL I

2360

STA

1961.1

STA

S-46

DOOR NO. 5

MAIN ENTRY

981187

(SHEET 1 OF 2)
 FIGURE 7: SECTION 46 LAP JOINT INSPECTION - GROUP 1, 2, 4, 5, 7, 8, 9 AND 10 AIRPLANES

December 18, 1991

Revision 2: October 30, 2008 747-53A2367

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 61 of 103

BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

The step number shown below agrees with the number shown in the circle symbol in the figure.

1. Do external surface HFEC inspections of the body longitudinal lap joint at stringer S-46. Do inspections of 

the skin at the upper row of fasteners in the lap joint shown. At protruding head fastener locations use 747 

Nondestructive Test Manual D6-7170, Part 6, Subject 51-00-00, Figure 4 or Figure 23. At countersunk 

fastener locations use 747 Nondestructive Test Manual D6-7170, Part 6, Subject 53-30-02, 53-30-03, or 

53-30-06.

DETAIL I

LOWER SKIN PANEL

UPPER SKIN PANEL

STRINGER 46

SPLICE

CIRCUMFERENTIAL

CENTERLINE

LAP SPLICE (TYPICAL)

LEFT SIDE ONLY

INDICATES AREA TO

BE INSPECTED

1

FWD

UP

981188

(SHEET 2 OF 2)
 FIGURE 8: SECTION 46 LAP JOINT INSPECTION - GROUP 3 AND 6 AIRPLANES

December 18, 1991

Revision 2: October 30, 2008 747-53A2367

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 62 of 103

BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

FIGURE 8: SECTION 46 LAP JOINT INSPECTION - GROUP 3 AND 6 AIRPLANES

STA

2140

STA

1961.10

STA

1741.10

STA

1480

LEFT SIDE ONLY

S-46

SEE DETAIL I

LAP SPLICE

MAIN ENTRY

DOOR NO. 4

OPENING

MAIN ENTRY

DOOR NO. 3

OPENING

FOR TYPICAL

981204

(SHEET 1 OF 2)
 FIGURE 8: SECTION 46 LAP JOINT INSPECTION - GROUP 3 AND 6 AIRPLANES

December 18, 1991

Revision 2: October 30, 2008 747-53A2367

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 63 of 103

BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

The step number shown below agrees with the number shown in the circle symbol in the figure.

1. Do external surface HFEC inspections of the body longitudinal lap joint at stringer S-46. Do inspections of 

the skin at the upper row of fasteners in the lap joint shown. At protruding head fastener locations use 747 

Nondestructive Test Manual D6-7170, Part 6, Subject 51-00-00, Figure 4 or Figure 23. At countersunk 

fastener locations use 747 Nondestructive Test Manual D6-7170, Part 6, Subject 53-30-02, 53-30-03, or 

53-30-06.

DETAIL I

UPPER SKIN PANEL

LAP SPLICE (TYPICAL)

LEFT SIDE ONLY

BE INSPECTED

INDICATES AREA TO

CENTERLINE

CIRCUMFERENTIAL

SPLICE

LOWER SKIN PANEL

STRINGER 46

1

UP

FWD

981239

(SHEET 2 OF 2)
 FIGURE 9: SECTION 41 LAP JOINT INSPECTION - GROUP 1, 3 AND 7 AIRPLANES

December 18, 1991

Revision 2: October 30, 2008 747-53A2367

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

FIGURE 9: SECTION 41 LAP JOINT INSPECTION - GROUP 1, 3 AND 7 AIRPLANES

S-23L

SEE DETAIL II

FOR TYPICAL LAP SPLICE

FORWARD

ENTRY DOOR

S-14

STA

520

STA

134

TYPICAL LEFT SIDE SHOWN

RIGHT SIDE OPPOSITE

S-19L

STA

340

STA

400

S-6

S-0

STA

134

DOOR OPENING

LEFT SIDE CREW

S-14L

S-6L

S-23L

A LEFT SIDE

AIRPLANES WITH

CREW DOOR 340

400

STA

STA STA

520

SEE DETAIL I

SEE DETAIL II

FOR TYPICAL LAP SPLICE

S-19L

A LEFT SIDE

AIRPLANES WITHOUT

CREW DOOR

1505225

(SHEET 1 OF 4)
 FIGURE 9: SECTION 41 LAP JOINT INSPECTION - GROUP 1, 3 AND 7 AIRPLANES

December 18, 1991

Revision 2: October 30, 2008 747-53A2367

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

LAP SPLICE

FOR TYPICAL

SEE DETAIL II

S-45R

S-45L

S-14R

S-6R

S-23R

LAP SPLICE

FOR TYPICAL

SEE DETAIL II

SEE DETAIL I

OPENING

CREW DOOR

RIGHT SIDE

134

STA

STA

340

400

STA

520

STA

S-0

S-19R

STA 

520

S-44L

S-44R

NOSE WHEEL WELL

BOTTOM VIEW

STA

134

SEE DETAIL II

FOR TYPICAL 

LAP SPLICE

STA

240 STA

340

S-39L

S-34L

DETAIL I

1505234

(SHEET 2 OF 4)
 FIGURE 9: SECTION 41 LAP JOINT INSPECTION - GROUP 1, 3 AND 7 AIRPLANES

December 18, 1991

Revision 2: October 30, 2008 747-53A2367

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

DETAIL II

LAP SPLICE (TYPICAL)

LEFT SIDE SHOWN

RIGHT SIDE OPPOSITE

CIRCUMFERENTIAL

SPLICE

INDICATES AREA TO

BE INSPECTED

LOWER SKIN PANEL

UPPER SKIN PANEL

STRINGER

CENTERLINE

FWD

UP

1

1476259

(SHEET 3 OF 4)
 FIGURE 9: SECTION 41 LAP JOINT INSPECTION - GROUP 1, 3 AND 7 AIRPLANES

December 18, 1991

Revision 2: October 30, 2008 747-53A2367

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 67 of 103

BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

The step number shown below agree with the number shown in the circle symbols in the figure. 

1. Do external surface HFEC inspections of the body longitudinal lap joints at stringers S-0, S-6, S-14, S-19, 

S-23, S-34, S-39, S-44, and S-45. Do inspections of the skin at the upper row of fasteners in the lap joints. 

At protruding head fastener locations use 747 Nondestructive Test Manual D6-7170, Part 6, Subject 51-

00-00, Figure 4 or Figure 23. At countersunk fastener locations use 747 Nondestructive Test Manual D6-

7170, Part 6, Subject 53-30-02, 53-30-03, or 53-30-06.

NOTE: At stringer S-6 between STA 400 (aft of crew door) and STA 520 if cracks are found in this area

contact Boeing. 

NOTE: At stringer S-44 between STA 400 and STA 440, also do inspections of the skin at the upper row

of fasteners common to the internal doubler installed in production.

(SHEET 4 OF 4)
 FIGURE 10: SECTION 41 LAP JOINT INSPECTION - GROUP 2, 4, 8 AND 9 AIRPLANES

December 18, 1991

Revision 2: October 30, 2008 747-53A2367

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

FIGURE 10: SECTION 41 LAP JOINT INSPECTION - GROUP 2, 4, 8 AND 9 AIRPLANES

S-14L

S-6L

STA

134

DOOR OPENING

LEFT SIDE CREW

S-14L

S-6L

S-23L

S-23L

A LEFT SIDE

AIRPLANES WITH

CREW DOOR

SEE DETAIL II

SEE DETAIL I

A LEFT SIDE CREW DOOR

AIRPLANES WITHOUT

340

400

STA

STA

STA

520

SEE DETAIL III

FOR TYPICAL LAP SPLICE

SEE DETAIL I

SEE DETAIL III

FOR TYPICAL LAP SPLICE

SEE DETAIL II

STA

520

340

STA

400

STA

STA

134

S-19L

S-0

S-19L

1505240

(SHEET 1 OF 4)
 FIGURE 10: SECTION 41 LAP JOINT INSPECTION - GROUP 2, 4, 8 AND 9 AIRPLANES

December 18, 1991

Revision 2: October 30, 2008 747-53A2367

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 69 of 103

BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

DETAIL I

SEE DETAIL III

FOR TYPICAL 

LAP SPLICE

SPLICE

FOR TYPICAL LAP

SEE DETAIL III

S-45R

S-45L

S-14R

S-6R

S-23R

BOTTOM VIEW

DETAIL II

SEE

LAP SPLICE

FOR TYPICAL

SEE DETAIL III

SEE DETAIL I

OPENING

CREW DOOR

RIGHT SIDE

134

STA

STA

340

400

STA

520

STA

STA 

520

S-44L

S-44R

NOSE WHEEL WELL

STA

134

S-0

S-19R

S-39L

S-34L

STA

240 STA

340

1505257

(SHEET 2 OF 4)
 FIGURE 10: SECTION 41 LAP JOINT INSPECTION - GROUP 2, 4, 8 AND 9 AIRPLANES

December 18, 1991

Revision 2: October 30, 2008 747-53A2367

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 70 of 103

BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

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

DETAIL III

DETAIL II

LOWER SKIN PANEL

RIGHT SIDE OPPOSITE

LEFT SIDE SHOWN

UPPER SKIN PANEL

STRINGER

INDICATES AREA TO

BE INSPECTED

SPLICE

CENTERLINE

LAP SPLICE (TYPICAL)

CIRCUMFERENTIAL

STRINGER 6

UPPER

SKIN PANEL

LOWER

SKIN PANEL

LOWER DOUBLER

CENTERLINE

UPPER DOUBLER

RIGHT SIDE OPPOSITE

LEFT SIDE SHOWN

LAP SPLICE (TYPICAL)

CIRCUMFERENTIAL

SPLICE

FWD

UP

1

2

FWD

UP

1476283

(SHEET 3 OF 4)
 FIGURE 10: SECTION 41 LAP JOINT INSPECTION - GROUP 2, 4, 8 AND 9 AIRPLANES

December 18, 1991

Revision 2: October 30, 2008 747-53A2367

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 71 of 103

BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

1. Do external surface HFEC inspections of the body longitudinal lap joints at stringers S-0, S-6, S-14, S-19, 

S-23, S-34, S-39, S-44, and S-45. Do inspections of the skin at the upper row of fasteners in the lap joints. 

At protruding head fastener locations use 747 Nondestructive Test Manual D6-7170, Part 6, Subject 51-

00-00, Figure 4 or Figure 23. At countersunk fastener locations use 747 Nondestructive Test Manual D6-

7170, Part 6, Subject 53-30-02, 53-30-03, or 53-30-06.

NOTE: At stringer S-44 between STA 400 and STA 440, also do inspections of the skin at the upper row

of fasteners common to the internal doubler installed in production.

2. Do an external surface HFEC inspection of the external doubler at the fasteners common to the upper row 

of the S-6 lap joint. External doublers were installed along S-6 by Service Bulletin 747-53-2272. At 

protruding head fastener locations use 747 Nondestructive Test Manual D6-7170, Part 6, Subject 51-00-

00, Figure 4 or Figure 23. At countersunk fastener locations use 747 Nondestructive Test Manual D6-7170, 

Part 6, Subject 53-30-02, 53-30-03, or 53-30-06.

NOTE: Start to do inspections of the lap joint at stringer S-6 10,000 flight-cycles after doublers are

installed as shown in Service Bulletin 747-53-2272 if airplane is not covered by Service Bulletin

747-53-2253. 

(SHEET 4 OF 4)
 FIGURE 11: SECTION 41 LAP JOINT INSPECTION - GROUP 5, 6, AND 10

December 18, 1991

Revision 2: October 30, 2008 747-53A2367

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 72 of 103

BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

FIGURE 11: SECTION 41 LAP JOINT INSPECTION - GROUP 5, 6, AND 10

AIRPLANES WITHOUT

CREW DOOR

A LEFT SIDE

CREW DOOR

A LEFT SIDE

AIRPLANES WITH

S-14L

S-23L

SEE DETAIL II

SEE DETAIL I

FOR TYPICAL LAP SPLICE

STA

134

S-6L

520

CREW DOOR OPENING

UPPER DECK LEFT SIDE

340

STA

STA

S-14L

S-6L

S-23L SEE DETAIL II

FOR TYPICAL LAP SPLICE

SEE DETAIL II

FOR TYPICAL 

LAP SPLICE

SEE DETAIL I

STA

520

340

STA

STA

134

400

STA

S-0

S-19L

400 S-0

STA

S-19L

SEE DETAIL II

FOR TYPICAL 

LAP SPLICE

1505261

(SHEET 1 OF 3)
 FIGURE 11: SECTION 41 LAP JOINT INSPECTION - GROUP 5, 6, AND 10

December 18, 1991

Revision 2: October 30, 2008 747-53A2367

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

S-23R

BOTTOM VIEW

SEE DETAIL I

134

STA

STA

340

520

STA

FOR TYPICAL 

LAP SPLICE

S-44L

S-44R

NOSE WHEEL WELL

STA

134

LAP SPLICE

FOR TYPICAL

SEE DETAIL II

SEE DETAIL II

S-6R

S-14R

LAP SPLICE

FOR TYPICAL

SEE DETAIL II

OPENING

CREW DOOR

RIGHT SIDE

S-45L

S-45R

SPLICE

SEE DETAIL II

FOR TYPICAL LAP

DETAIL I

STA

520

STA

S-0 400

STA

240 STA

340

S-39L

S-34L

S-19R

1505265

(SHEET 2 OF 3)
 FIGURE 11: SECTION 41 LAP JOINT INSPECTION - GROUP 5, 6, AND 10

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

The step number shown below agree with the number shown in the circle symbols in the figure. 

1. Do external surface HFEC inspections of the body longitudinal lap joints at stringers S-0, S-6, S-14, S-19, 

S-23, S-34, S-39, S-44, and S-45. Do inspections of the skin at the upper row of fasteners in the lap joints 

shown. At protruding head fastener locations use 747 Nondestructive Test Manual D6-7170, Part 6, 

Subject 51-00-00, Figure 4 or Figure 23. At countersunk fastener locations use 747 Nondestructive Test 

Manual D6-7170, Part 6, Subject 53-30-02, 53-30-03, or 53-30-06.

NOTE: At stringer S-44 between STA 400 and STA 440, also do inspections of the skin at the upper row

of fasteners common to the internal doubler installed in production.

DETAIL II

CIRCUMFERENTIAL

SPLICE UPPER SKIN PANEL

LOWER SKIN PANEL

STRINGER

CENTERLINE

INDICATES AREA TO

BE INSPECTED

RIGHT SIDE OPPOSITE

LEFT SIDE SHOWN

LAP SPLICE (TYPICAL)

FWD

UP

1

1476361

(SHEET 3 OF 3)
 FIGURE 12: SECTION 42 LAP JOINT INSPECTION - GROUP 1, 2, 4, 5, 7, 8 AND 9 AIRPLANES

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

FIGURE 12: SECTION 42 LAP JOINT INSPECTION - GROUP 1, 2, 4, 5, 7, 8 AND 9 AIRPLANES 

1000

520 STA

STA

S-0

S-6L

S-12L

DOOR 2

MAIN ENTRY

DOOR 2

MAIN ENTRY

FORWARD

CARGO

DOOR

S-0

BL-0

S-19L

S-23L

S-34L

S-39L

S-44R

S-39R

S-34R

S-23R

S-19R

S-12R

S-6R

741

STA

STA

941

S-44L

STA

881

STA

800

STA

763

SEE DETAIL I

FOR TYPICAL

LAP SPLICE

STA

720 782

STA

INSPECTIONS NOT

REQUIRED FOR SUD

AIRPLANES

FWD

1476809

(SHEET 1 OF 2)
 FIGURE 12: SECTION 42 LAP JOINT INSPECTION - GROUP 1, 2, 4, 5, 7, 8 AND 9 AIRPLANES

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

The step number shown below agree with the number shown in the circle symbols in the figure.

1. Do external surface HFEC inspections of the body longitudinal lap joints at stringers S-0, S-6, S-12, S-19, 

S-23, S-34, S-39 and S-44. Do inspections of the skin at the upper row of fasteners in the lap joints shown. 

At protruding head fastener locations use 747 Nondestructive Test Manual D6-7170, Part 6, Subject 51-

00-00, Figure 4 or 23. At countersunk fastener locations use 747 Nondestructive Test Manual D6-7170, 

Part 6, Subject 53-30-02, 53-30-03, or 53-30-06.

NOTE: Group 2 Airplanes (SUD) do not need to do inspections at stringer locations S-0 body station

741.10 to 941.10 and S-6 body station 741.10 to 941.10. 

DETAIL I

UPPER SKIN PANEL

STRINGER

CENTERLINE

CIRCUMFERENTIAL

SPLICE

LOWER SKIN PANEL

BE INSPECTED

INDICATES AREA TO

RIGHT SIDE OPPOSITE

LEFT SIDE SHOWN

LAP SPLICE (TYPICAL)

UP

FWD

1

1476810

(SHEET 2 OF 2)
 FIGURE 13: SECTION 42 - LAP JOINT INSPECTION - GROUP 10

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

FIGURE 13: SECTION 42 - LAP JOINT INSPECTION - GROUP 10

1000

520 STA

STA

S-0

S-6L

S-12L

DOOR 2

MAIN ENTRY

DOOR 2

MAIN ENTRY

FORWARD

CARGO

DOOR

S-0

BL-0

S-19L

S-23L

S-34L

S-39L

S-44R

S-39R

S-34R

S-23R

S-19R

S-12R

S-6R

741

STA

STA

941

S-44L

STA

881

STA

800

STA

763

SEE DETAIL I

FOR TYPICAL

LAP SPLICE

STA

782

720

STA

712

STA

688

STA

FWD

1505270

(SHEET 1 OF 2)
 FIGURE 13: SECTION 42 - LAP JOINT INSPECTION - GROUP 10

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

The step number shown below agree with the number shown in the circle symbols in the figure.

1. Do external surface HFEC inspections of the body longitudinal lap joints at stringers S-0, S-6, S-12, S-19, 

S-23, S-34, S-39 and S-44. Do inspections of the skin at the upper row of fasteners in the lap joints shown. 

At protruding head fastener locations use 747 Nondestructive Test Manual D6-7170, Part 6, Subject 51-

00-00, Figure 4 or 23. At countersunk fastener locations use 747 Nondestructive Test Manual D6-7170, 

Part 6, Subject 53-30-02, 53-30-03, or 53-30-06.

DETAIL I

UPPER SKIN PANEL

STRINGER

CENTERLINE

CIRCUMFERENTIAL

SPLICE

LOWER SKIN PANEL

BE INSPECTED

INDICATES AREA TO

RIGHT SIDE OPPOSITE

LEFT SIDE SHOWN

LAP SPLICE (TYPICAL)

UP

FWD

1

1503502

(SHEET 2 OF 2)
 FIGURE 14: SECTION 46 - LAP JOINT INSPECTION - GROUPS 1, 2, 4 AND 5

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

FIGURE 14: SECTION 46 - LAP JOINT INSPECTION - GROUPS 1, 2, 4 AND 5

1480

STA

AFT CARGO

DOOR

NO. 4

ENTRY DOOR

BL-0 BL-0

STR-34L

STR-40L

STR-46L

STR-23L

STR-19L

STR-12L

STR-12R

STR-23R

STR-19R

STR-46R

STR-40R

STR-34R

ENTRY DOOR

NO. 4

STA

1961

STR-4R

STR-4L

STA

1572.50 1741

STA

1662

STA

SEE DETAIL I

FOR TYPICAL

LAP SPLICE

STA

1930

STA

1779

STA

1760

STA

1640

1505271

(SHEET 1 OF 3)
 FIGURE 14: SECTION 46 - LAP JOINT INSPECTION - GROUPS 1, 2, 4 AND 5

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

2360

DOOR NO. 5

MAIN ENTRY

DOOR

BULK

CARGO

BL-0

S-46R

S-23R

S-34R

S-19R

S-12R

S-12L

S-19L

S-23L

S-34L

S-46L

STA

1961

STA

STA

2181

S-4L

S-4R

STA

2200 STA

2320

FWD

1505273

(SHEET 2 OF 3)
 FIGURE 14: SECTION 46 - LAP JOINT INSPECTION - GROUPS 1, 2, 4 AND 5

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

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

1. Do external surface HFEC inspections of the body longitudinal lap joint at stringer S-4, S-12, S-19, S-23, 

S-34, S-40 and S-46. Do inspections of the skin at the upper row of fasteners in the lap joint shown. At 

protruding head fastener locations use 747 Nondestructive Test Manual D6-7170, Part 6, Subject 51-00-

00, Figure 4 or 23. At countersunk fastener locations use 747 Nondestructive Test Manual D6-7170, Part 

6, Subject 53-30-02, 53-30-03, or 53-30-06.

DETAIL I

LOWER SKIN PANEL

UPPER SKIN PANEL

STRINGER 46

SPLICE

CIRCUMFERENTIAL

CENTERLINE

LAP SPLICE (TYPICAL)

LEFT SIDE ONLY

INDICATES AREA TO

BE INSPECTED

1

FWD

UP

1479035

(SHEET 3 OF 3)
 FIGURE 15: SECTION 41, STRINGER 6 - LAP JOINT MODIFICATION - GROUP 1, 2, 4, 5, 7, 8, 9 AND 10 

AIRPLANES

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

FIGURE 15: SECTION 41, STRINGER 6 - LAP JOINT MODIFICATION - GROUP 1, 2, 4, 5, 7, 8, 9 AND 10 

AIRPLANES

AIRPLANES WITHOUT

CREW DOOR

A LEFT SIDE

CREW DOOR

A LEFT SIDE

AIRPLANES WITH

STA

134

S-6L

520

CREW DOOR OPENING

UPPER DECK LEFT SIDE

340

STA

STA

S-6L

STA

520

340

STA

STA

134

400

STA

400

STA

STA

222

STA

222

1

1

2

2

1479038

(SHEET 1 OF 2)
 FIGURE 15: SECTION 41, STRINGER 6 - LAP JOINT MODIFICATION - GROUP 1, 2, 4, 5, 7, 8, 9 AND 10 

AIRPLANES

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

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

NOTE: If S-6 between BS 340 and BS 400 has been modified by Service Bulletin 747-53-2253 or Service

Bulletin 747-53-2272 then there is no modification required by this Service Bulletin.

1. Do the inspection of the lap joint as given in Figures 2, 3 or 4 as applicable. 

2. If no cracks are found, do the lap joint repair/modification as given in drawing 691U1049, sheet 1. The 

modification drawing references existing Boeing Service Bulletins for acceptable modifications in this area. 

If cracks are found, contact Boeing for modification instructions. 

NOTE: At stringer S-6 between STA 400 (aft of crew door) and STA 520 if cracks are found in this area

contact Boeing. 

134

STA

STA

340

520

STA

S-6R

OPENING

CREW DOOR

RIGHT SIDE

STA

400

STA

222

1 2

1479040

(SHEET 2 OF 2)
 FIGURE 16: SECTION 41, STRINGER 23 - LAP JOINT MODIFICATION - GROUP 1, 2, 4, 5, 7, 8, 9 AND 

10 AIRPLANES

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

FIGURE 16: SECTION 41, STRINGER 23 - LAP JOINT MODIFICATION - GROUP 1, 2, 4, 5, 7, 8, 9 AND 10 

AIRPLANES 

AIRPLANES WITHOUT

CREW DOOR

A LEFT SIDE

CREW DOOR

A LEFT SIDE

AIRPLANES WITH

S-23L

STA

134

520

CREW DOOR OPENING

UPPER DECK LEFT SIDE

340

STA

STA

S-23L

STA

520

340

STA

STA

134

400

STA

400

STA

STA

222

STA

222

1

1

2

2

1492564

(SHEET 1 OF 3)
 FIGURE 16: SECTION 41, STRINGER 23 - LAP JOINT MODIFICATION - GROUP 1, 2, 4, 5, 7, 8, 9 AND 

10 AIRPLANES

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

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

1. Do inspections of the lap joint as given in Figures 2, 3 or 4 as applicable.

S-23R

134

STA

STA

340

520

STA

STA

400

STA

222

S-23R

134

STA

STA

340

520

STA

OPENING

CREW DOOR

RIGHT SIDE

STA

400

STA

222

1 2

1 2

1492569

(SHEET 2 OF 3)
 FIGURE 16: SECTION 41, STRINGER 23 - LAP JOINT MODIFICATION - GROUP 1, 2, 4, 5, 7, 8, 9 AND 

10 AIRPLANES

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

2. If no cracks are found, do the lap joint modification as given in drawing 691U1050, sheet 1. If cracks are 

found, contact Boeing for modification instructions. 

(SHEET 3 OF 3)
 FIGURE 17: SECTION 42, 44 AND 46 LAP JOINT INSPECTION - GROUP 3 AND 6 AIRPLANES

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

FIGURE 17: SECTION 42, 44 AND 46 LAP JOINT INSPECTION - GROUP 3 AND 6 AIRPLANES

FWD SECTION 42

LEFT SIDE SHOWN

RIGHT SIDE OPPOSITE

WITH CARGO DOOR

OPENING

DOOR NO. 2

MAIN ENTRY

LAP SPLICE

FOR TYPICAL

SEE DETAIL II

S-44

S-23

1000

STA

560

STA

520 STA

S-39

S-34

S-19

S-12

S-6

S-0

FORWARD CARGO

DOOR SIDE

RIGHT SIDE ONLY

LAP SPLICE

FOR TYPICAL

SEE DETAIL I

1505279

(SHEET 1 OF 5)
 FIGURE 17: SECTION 42, 44 AND 46 LAP JOINT INSPECTION - GROUP 3 AND 6 AIRPLANES

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

S-12

STA

1241

SEE DETAIL I FOR

TYPICAL LAP SPLICE

STA

1350

STA

1480

STA

1000

S-4

S-19

S-23

STA

1000

SECTION 44

RIGHT SIDE SHOWN

LEFT SIDE OPPOSITE

1505280

(SHEET 2 OF 5)
 FIGURE 17: SECTION 42, 44 AND 46 LAP JOINT INSPECTION - GROUP 3 AND 6 AIRPLANES

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

STA

2140

STA

1961.10

STA

1741.10

STA

1480

LEFT SIDE SHOWN

RIGHT SIDE OPPOSITE

WITH CARGO DOOR

S-46

SEE DETAIL I

LAP SPLICE

MAIN ENTRY

DOOR NO. 4

OPENING

MAIN ENTRY

DOOR NO. 3

OPENING

FOR TYPICAL

SECTION 46

S-40

S-34

S-23

S-19

S-12

S-4

S-0

CARGO DOOR

RIGHT SIDE ONLY

1505281

(SHEET 3 OF 5)
 FIGURE 17: SECTION 42, 44 AND 46 LAP JOINT INSPECTION - GROUP 3 AND 6 AIRPLANES

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

DETAIL I

LAP SPLICE (TYPICAL)

LEFT SIDE SHOWN

RIGHT SIDE OPPOSITE

CIRCUMFERENTIAL

SPLICE

INDICATES AREA TO

BE INSPECTED

LOWER SKIN PANEL

UPPER SKIN PANEL

STRINGER

CENTERLINE

FWD

UP

1

1505283

(SHEET 4 OF 5)
 FIGURE 17: SECTION 42, 44 AND 46 LAP JOINT INSPECTION - GROUP 3 AND 6 AIRPLANES

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

The step numbers shown below agrees with the number shown in the circle symbol in the figure.

1. Do external surface HFEC inspections of the body longitudinal lap joint at stringers S-0, S-4, S-6, S-14, S19, S-23, S-34, S-39, S-40, S-44, S-45 and S-46. Do inspections of the skin at the upper row of fasteners 

in the lap joint shown. At protruding head fastener locations use 747 Nondestructive Test Manual D6-7170, 

Part 6, Subject 51-00-00, Figure 4 or Figure 23. At countersunk fastener locations use 747 Nondestructive 

Test Manual D6-7170, Part 6, Subject 53-30-02, 53-30-03, or 53-30-06.

2. Do external surface HFEC inspections of the body longitudinal lap joint at stringers S-0, S-6, S-12, S-19, 

S-23, S-34, S-39 and S-44. Do inspections of the skin at the upper row of fasteners in the lap joint shown. 

At protruding head fastener locations use 747 Nondestructive Test Manual D6-7170, Part 6, Subject 51-

00-00, Figure 4 or Figure 23. At countersunk fastener locations use 747 Nondestructive Test Manual D6-

7170, Part 6, Subject 53-30-02, 53-30-03, or 53-30-06.

No lap joint modification instructions are included for Group 3 and Group 6 airplanes. Contact Boeing if you 

intend to operate a Group 3 or Group 6 airplane after 30,000 total flight cycles.

DETAIL II

UPPER SKIN PANEL

LAP SPLICE (TYPICAL)

LEFT SIDE ONLY

BE INSPECTED

INDICATES AREA TO

CENTERLINE

CIRCUMFERENTIAL

SPLICE

LOWER SKIN PANEL

STRINGER

2

UP

FWD

1505285

(SHEET 5 OF 5)
 FIGURE 18: SECTION 41, STRINGER 44 - LAP JOINT MODIFICATION - GROUP 1, 2, 4, 5, 7, 8, 9 AND 

10 AIRPLANES

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

FIGURE 18: SECTION 41, STRINGER 44 - LAP JOINT MODIFICATION - GROUP 1, 2, 4, 5, 7, 8, 9 AND 10 

AIRPLANES

S-23R

BOTTOM VIEW

SEE DETAIL I

134

STA

STA

340

520

STA

S-44L

S-44R

NOSE WHEEL WELL

STA

134

S-6R

S-14R

OPENING

CREW DOOR

RIGHT SIDE

DETAIL I

STA

520

STA

S-0 400

STA

240 STA

340

STA

222

STA

400

1 2

1492399

(SHEET 1 OF 2)
 FIGURE 18: SECTION 41, STRINGER 44 - LAP JOINT MODIFICATION - GROUP 1, 2, 4, 5, 7, 8, 9 AND 

10 AIRPLANES

December 18, 1991

Revision 2: October 30, 2008 747-53A2367

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

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

1. Do the inspection of the lap joint as given in Figures 2, 3 or 4 as applicable.

2. If no cracks are found, do the lap joint modification as given in drawing 691U1051, sheet 1. If cracks are 

found, contact Boeing for modification instructions. 

(SHEET 2 OF 2)
 FIGURE 19: SECTION 42, STRINGER 44 - LAP JOINT MODIFICATION - GROUP 1, 2, 4, 5, 7, 8, 9 AND 

10 AIRPLANES

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

FIGURE 19: SECTION 42, STRINGER 44 - LAP JOINT MODIFICATION - GROUP 1, 2, 4, 5, 7, 8, 9 AND 10 

AIRPLANES

1000

520 STA

STA

S-0

S-6L

S-12L

DOOR 2

MAIN ENTRY

DOOR 2

MAIN ENTRY

FORWARD

CARGO

DOOR

S-0

BL-0

S-19L

S-23L

S-34L

S-39L

S-44R

S-39R

S-34R

S-23R

S-19R

S-12R

S-6R

740

STA

STA

941

S-44L

STA

881

STA

800

STA

763

FWD

1 2

1492403

(SHEET 1 OF 2)
 FIGURE 19: SECTION 42, STRINGER 44 - LAP JOINT MODIFICATION - GROUP 1, 2, 4, 5, 7, 8, 9 AND 

10 AIRPLANES

December 18, 1991

Revision 2: October 30, 2008 747-53A2367

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

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

1. Do the inspection of the lap joint as given in Figure 5. 

2. If no cracks are found, do the lap joint modification as given in drawing 691U1052, sheet 1. If cracks are 

found, contact Boeing for modification instructions. 

(SHEET 2 OF 2)
 FIGURE 20: SECTION 46 LAP JOINT INSPECTION - GROUP 7, 8, 9 AIRPLANES

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

FIGURE 20: SECTION 46 LAP JOINT INSPECTION - GROUP 7, 8, 9 AIRPLANES 

STA

1480

AFT CARGO

DOOR

NO. 4

ENTRY DOOR

BL-0 BL-0

STR-34L

STR-40L

STR-46L

STR-23L

STR-19L

STR-12L

STR-12R

STR-23R

STR-19R

STR-46R

STR-40R

STR-34R

ENTRY DOOR

NO. 4

STA

1961

STR-4R

STR-4L

STA

1741

STA

1572.50

STA

1662

SEE DETAIL I

FOR TYPICAL

LAP SPLICE

STA

1930

STA

1779

STA

1760

STA

1640

STA

1520

STA

1720

INSPECTION NOT REQUIRED

FOR AIRPLANES R1587-R1699

SEE B

SEE A

1503582

(SHEET 1 OF 5)
 FIGURE 20: SECTION 46 LAP JOINT INSPECTION - GROUP 7, 8, 9 AIRPLANES

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

2360

DOOR NO. 5

MAIN ENTRY

DOOR

BULK

CARGO

BL-0

S-46R

S-23R

S-34R

S-19R

S-12R

S-12L

S-19L

S-23L

S-34L

S-46L

STA

1961

STA

STA

2181

S-4L

S-4R

STA

2200 STA

2320

STA

1980

FWD

SEE C

1503557

(SHEET 2 OF 5)
 FIGURE 20: SECTION 46 LAP JOINT INSPECTION - GROUP 7, 8, 9 AIRPLANES

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

DETAIL I

LOWER SKIN PANEL

UPPER SKIN PANEL

STRINGER 46

SPLICE

CIRCUMFERENTIAL

CENTERLINE

LAP SPLICE (TYPICAL)

LEFT SIDE ONLY

INDICATES AREA TO

BE INSPECTED

1

FWD

UP

1503539

(SHEET 3 OF 5)
 FIGURE 20: SECTION 46 LAP JOINT INSPECTION - GROUP 7, 8, 9 AIRPLANES

December 18, 1991

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BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

STA

1720

STA

OVERLAPPING 1740

SKIN PANEL

OVERLAPPED

SKIN PANEL

DOUBLER

INDICATES AREA TO

BE INSPECTED

INDICATES AREA TO

BE INSPECTED

S-4

STA

1741

STA

1760

DOUBLER

UPPER SKIN

PANEL

LOWER SKIN

PANEL

TYPICAL, STA 1741.1 TO

STA 1961.1

DOUBLERS

FWD

FWD

A

2

B

1

1504136

(SHEET 4 OF 5)
 FIGURE 20: SECTION 46 LAP JOINT INSPECTION - GROUP 7, 8, 9 AIRPLANES

December 18, 1991

Revision 2: October 30, 2008 747-53A2367

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 100 of 103

BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

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

1. Do external surface HFEC inspections of the body longitudinal lap joint at stringer S-4, S-12, S-19, S-23, 

S-34, S-40 and S-46. Do inspections of the skin at the upper row of fasteners in the lap joint shown. At 

protruding head fastener locations use 747 Nondestructive Test Manual D6-7170, Part 6, Subject 51-00-

00, Figure 4 or 23. At countersunk fastener locations use 747 Nondestructive Test Manual D6-7170, Part 

6, Subject 53-30-02, 53-30-03, or 53-30-06.

2. Do internal surface LFEC inspections of the body longitudinal lap joint at stringer S-4. Do inspections of the 

skin at the upper row of fasteners in the lap joint shown. Use 747 Nondestructive Test Manual D6-7170, 

Part 6, Subject 53-30-00, Figure 5.

NOTE: At stringer 4 left, between STA 1720 and STA 1740, and between STA 1960 and STA 1980. This

inspection in this area should only be repeated every 1,500 flight -cycles. This inspection is of the

upper skin, which is covered by an external doubler. 

STA

1961.1 STA

1980

OVERLAPPING

SKIN PANEL

OVERLAPPED

SKIN PANEL

DOUBLER

INDICATES AREA TO

BE INSPECTED

S-4L

FWD

C

2

1504137

(SHEET 5 OF 5)
 FIGURE 21: SECTION 46 - LAP JOINT INSPECTION - GROUP 10 AIRPLANES

December 18, 1991

Revision 2: October 30, 2008 747-53A2367

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 101 of 103

BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

FIGURE 21: SECTION 46 - LAP JOINT INSPECTION - GROUP 10 AIRPLANES 

1480

STA

AFT CARGO

DOOR

NO. 4

ENTRY DOOR

BL-0 BL-0

STR-34L

STR-40L

STR-46L

STR-23L

STR-19L

STR-12L

STR-12R

STR-23R

STR-19R

STR-46R

STR-40R

STR-34R

ENTRY DOOR

NO. 4

STA

1961

STR-4R

STR-4L

STA

1572.50 1741

STA

1662

STA

SEE DETAIL I

FOR TYPICAL

LAP SPLICE

STA

1930

STA

1779

STA

1760

STA

1640

STA

1759

STA

1757

STA

1752

1503597

(SHEET 1 OF 3)
 FIGURE 21: SECTION 46 - LAP JOINT INSPECTION - GROUP 10 AIRPLANES

December 18, 1991

Revision 2: October 30, 2008 747-53A2367

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 102 of 103

BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

2360

DOOR NO. 5

MAIN ENTRY

DOOR

BULK

CARGO

BL-0

S-46R

S-23R

S-34R

S-19R

S-12R

S-12L

S-19L

S-23L

S-34L

S-46L

STA

1961

STA

STA

2181

S-4L

S-4R

STA

2200 STA

2320

FWD

1503559

(SHEET 2 OF 3)
 FIGURE 21: SECTION 46 - LAP JOINT INSPECTION - GROUP 10 AIRPLANES

December 18, 1991

Revision 2: October 30, 2008 747-53A2367

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 103 of 103

BOEING SERVICE BULLETIN 747-53A2367

ALERT ALERT

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

1. Do external surface HFEC inspections of the body longitudinal lap joint at stringer S-4, S-12, S-19, S-23, 

S-34, S-40 and S-46. Do inspections of the skin at the upper row of fasteners in the lap joint shown. At 

protruding head fastener locations use 747 Nondestructive Test Manual D6-7170, Part 6, Subject 51-00-

00, Figure 4 or 23. At countersunk fastener locations use 747 Nondestructive Test Manual D6-7170, Part 

6, Subject 53-30-02, 53-30-03, or 53-30-06.

DETAIL I

LOWER SKIN PANEL

UPPER SKIN PANEL

STRINGER 46

SPLICE

CIRCUMFERENTIAL

CENTERLINE

LAP SPLICE (TYPICAL)

LEFT SIDE ONLY

INDICATES AREA TO

BE INSPECTED

1

FWD

UP

1503541

(SHEET 3 OF 3)