December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 1 of 103 ALERT ALERT 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## BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET Copyright © 1991 The Boeing Company Unpublished Work - All Rights Reserved Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable subject matter.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or otherwise.**BLANK PAGE** December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 2 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT**

BLANK PAGE**Table of Contents** December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 3 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **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** December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 4 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT** 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 . . . . . . . . . . 101December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 5 of 103 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.December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 6 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT** — 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, 2008December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 7 of 103 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.December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 8 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT 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.December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 9 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT**

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 JOINTS AT STRINGERS 6,23 AND 44 SECTION 41 (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) SECTION 46 STA

S-4 1480 STA 2360

S-12

S-12 SECTION 441479023December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 10 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT**

BLANK PAGEDecember 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 11 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

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.December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 12 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT**

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**December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 13 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT** 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–RS240December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 14 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT** 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 RG172December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 15 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT** 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 RD658December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 16 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT** 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–RS320December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 17 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT** 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 RD357December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 18 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT** 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 7December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 19 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT**

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**December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 20 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT**

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**December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 21 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT**

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**December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 22 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT**

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**December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 23 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT**

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 accomplishedon 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.December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 24 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT 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.December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 25 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT**

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.December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 26 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT**

**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,December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 27 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT** 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)December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 28 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT**

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)**December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 29 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT**

**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.December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 30 of 103 

### 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.December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 31 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **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 JointsDecember 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 32 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT**

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)** December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 33 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT**

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.December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 34 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **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- -December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 35 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **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 ManualDecember 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 36 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT**

BLANK PAGEDecember 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 37 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **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.December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 38 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT**

BLANK PAGEDecember 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 39 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **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.December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 40 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **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.December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 41 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **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.December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 42 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **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.December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 43 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT** (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**  December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 44 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT 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** December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 45 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **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 OPPOSITE981144

**(SHEET 1 OF 3) FIGURE 2: 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. 46 of 103 

### 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 1981145

**(SHEET 2 OF 3) FIGURE 2: 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. 47 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **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**  December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 48 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT FIGURE 3: SECTION 41 LAP JOINT INSPE**  **CTION - 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 140981148

**(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 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 49 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

140 STA STA 340 400 STA 520 STA

STA 520

S-44L S-44R NOSE WHEEL WELL STA 140981149

**(SHEET 2 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. 50 of 103 

### 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 UP981152

**(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 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 52 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT FIGURE 4: SECTION 41 LAP JOINT IN**  **SPECTION - 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 140981153

**(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 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 53 of 103 

### 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 520981155

**(SHEET 2 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. 54 of 103 

### 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 1981158

**(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 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 56 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT FIGURE 5: SECTION 42 LAP JO**  **INT 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 STA 520 STA981159

**(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 1981160

**(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 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 58 of 103 

### 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 STA981112

**(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 UP981117

**(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 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 60 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT FIGURE 7: SECTION 46 LAP JO**  **INT 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 ENTRY981187

**(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 UP981188

**(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 TYPICAL981204

**(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
FWD981239

**(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 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 64 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT FIGURE 9: SECTION 41 LAP JOINT IN**  **SPECTION - 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 DOOR1505225

**(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 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 65 of 103 

### 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 I1505234

**(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 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 66 of 103 

### 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 11476259

**(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 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 68 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT FIGURE 10: SECTION 41 LAP JOINT INSPEC**  **TION - 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-19L1505240

**(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 3401505257

**(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 UP1476283

**(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

S-0 400 STA

S-19L SEE DETAIL II FOR TYPICAL LAP SPLICE1505261

**(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 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 73 of 103 

### 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 400 S-0

STA 240 STA 340

S-39L S-34L S-19R1505265

**(SHEET 2 OF 3) 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. 74 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 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 11476361

**(SHEET 3 OF 3) FIGURE 12: SECTION 42 LAP JOINT INSPECTION - GROUP 1, 2, 4, 5, 7, 8 AND 9 AIRPLANES**  December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 75 of 103 

### 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 STA 520 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 INSPECTIONS NOT REQUIRED FOR SUD AIRPLANES

FWD1476809

**(SHEET 1 OF 2) FIGURE 12: SECTION 42 LAP JOINT INSPECTION - GROUP 1, 2, 4, 5, 7, 8 AND 9 AIRPLANES**  December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 76 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-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 11476810

**(SHEET 2 OF 2) FIGURE 13: SECTION 42 - LAP JOINT INSPECTION - GROUP 10**  December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 77 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT FIGURE 13: SECTION 42 - LAP JOINT INSPECTION - GROUP 10** 

1000 STA 520 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

FWD1505270

**(SHEET 1 OF 2) FIGURE 13: SECTION 42 - LAP JOINT INSPECTION - GROUP 10**  December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 78 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-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 11503502

**(SHEET 2 OF 2) FIGURE 14: SECTION 46 - LAP JOINT INSPECTION - GROUPS 1, 2, 4 AND 5**  December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 79 of 103 

### 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 1741 1572.50 STA 1662 STA

SEE DETAIL I FOR TYPICAL LAP SPLICE STA 1930 STA 1779 STA 1760 STA 16401505271

**(SHEET 1 OF 3) FIGURE 14: SECTION 46 - LAP JOINT INSPECTION - GROUPS 1, 2, 4 AND 5**  December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 80 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

FWD1505273

**(SHEET 2 OF 3) FIGURE 14: SECTION 46 - LAP JOINT INSPECTION - GROUPS 1, 2, 4 AND 5**  December 18, 1991 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 81 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 UP1479035

**(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 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 82 of 103 

### 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

21479038

**(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 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 83 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. **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 21479040

**(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 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 84 of 103 

### 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

21492564

**(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 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 85 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 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 21492569

**(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 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 86 of 103 

### 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 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 87 of 103 

### 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 I1505279

**(SHEET 1 OF 5) FIGURE 17: SECTION 42, 44 AND 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. 88 of 103 

### 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 OPPOSITE1505280

**(SHEET 2 OF 5) FIGURE 17: SECTION 42, 44 AND 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. 89 of 103 

### 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 ONLY1505281

**(SHEET 3 OF 5) FIGURE 17: SECTION 42, 44 AND 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. 90 of 103 

### 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 11505283

**(SHEET 4 OF 5) FIGURE 17: SECTION 42, 44 AND 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. 91 of 103 

### 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
FWD1505285

**(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 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 92 of 103 

### 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 400 S-0

STA 240 STA 340 STA 222

STA 400

1 21492399

**(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 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 93 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 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 Revision 2: October 30, 2008 747-53A2367 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 94 of 103 

### 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 STA 520 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 21492403

**(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 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 95 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 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 IN**  **SPECTION - 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. 96 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT FIGURE 20: SECTION 46 LAP JOINT INSP**  **ECTION - 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 A1503582

**(SHEET 1 OF 5) FIGURE 20: SECTION 46 LAP JOINT IN**  **SPECTION - 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. 97 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 STA 1980

FWD

C SEE1503557

**(SHEET 2 OF 5) FIGURE 20: SECTION 46 LAP JOINT IN**  **SPECTION - 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. 98 of 103 

### 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 UP1503539

**(SHEET 3 OF 5) FIGURE 20: SECTION 46 LAP JOINT IN**  **SPECTION - 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. 99 of 103 

### BOEING SERVICE BULLETIN 747-53A2367 **ALERT ALERT**

STA 1720 STA 1740 OVERLAPPING 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 11504136

**(SHEET 4 OF 5) FIGURE 20: SECTION 46 LAP JOINT IN**  **SPECTION - 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 174 0, 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 21504137

**(SHEET 5 OF 5) FIGURE 21: SECTION 46 - LAP JOIN**  **T 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 1741 1572.50 STA 1662 STA

SEE DETAIL I FOR TYPICAL LAP SPLICE STA 1930 STA 1779 STA 1760 STA 1640

STA 1759 STA 1757 STA 17521503597

**(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

FWD1503559

**(SHEET 2 OF 3) FIGURE 21: SECTION 46 - LAP JOIN**  **T 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 UP1503541

**(SHEET 3 OF 3)**