August 21, 2003

Revision 2: November 16, 2006 747-21A2422

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 1 of 46

Commercial

Airplane

Group 747

Service Bulletin

Number: 747-21A2422

Date: August 21, 2003

Revision 2: November 16, 2006

ATA System: 2122

SUBJECT: AIR CONDITIONING - Distribution - Duct Insulation, BMS 8-39 Foam, Replacement

BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET

Copyright © 2003 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Unpublished Work - All Rights Reserved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.
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BOEING SERVICE BULLETIN 747-21A2422

BLANK PAGE
 Table of Contents

August 21, 2003

Revision 2: November 16, 2006 747-21A2422

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BOEING SERVICE BULLETIN 747-21A2422

Table of Contents

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

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

1. PLANNING INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

A. Effectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

1. Airplanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

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

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

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

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

E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

H. Weight and Balance Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

1. Existing Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

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

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

4. Process Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . 24

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

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

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

C. Parts Necessary For Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

1. Kits/Parts: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

2. Parts and Materials Supplied by the Operator: . . . . . . . . . . . . . . . . . . . . . . 27

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

4. Parts Removed and Not Replaced: . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

D. Parts Necessary to Change Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

F. Special Tooling Necessary to do this Service Bulletin . . . . . . . . . . . . . . . . . . . . . 28

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

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

B. WORK INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

FIGURE 1: DUCT ACCESS, ALL AIRPLANE GROUPS . . . . . . . . . . . . . . . . . . . . . . . . 30

FIGURE 2: DUCT ASSEMBLY REWORK, GROUP 1 AIRPLANES . . . . . . . . . . . . . . . . . . 32

FIGURE 3: DUCT ASSEMBLY REWORK, GROUP 2 AIRPLANES . . . . . . . . . . . . . . . . . . 34

FIGURE 4: DUCT ASSEMBLY REWORK, GROUP 3 AIRPLANES . . . . . . . . . . . . . . . . . . 36

FIGURE 5: DUCT ASSEMBLY REWORK, GROUP 4 AIRPLANES . . . . . . . . . . . . . . . . . . 38

APPENDIX A: PROCESS DATA - APPLICATION OF BMS 8-300 BY TAPING WITH BMS 5-157 TAPE.

40

APPENDIX B: BAC 5412 METHOD VII - BONDING DUCT JOINTS. . . . . . . . . . . . . . . . . . 45

APPENDIX C: BAC 5412 METHOD VIII - TAPED TELESCOPING JOINTS. . . . . . . . . . . . . . 46
 Table of Contents

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BOEING SERVICE BULLETIN 747-21A2422

BLANK PAGE
August 21, 2003

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Commercial

Airplane

Group 747

Service Bulletin

Number: 747-21A2422 Revision Transmittal Sheet

Date: August 21, 2003

Revision 2: November 16, 2006

ATA System: 2122

SUBJECT: AIR CONDITIONING - Distribution - Duct Insulation, BMS 8-39 Foam, Replacement

This Revision includes all pages of the service bulletin.

COMPLIANCE INFORMATION RELATED TO THIS REVISION

More work is necessary on airplanes changed as shown in the initial release or Revision 01 of this service 

bulletin, if accomplished after September 02, 2005. If the intent of this Revision 02 was accomplished after 

September 02, 2005, then no more work is required.

REASON FOR REVISION

This revision is sent to give operators approval to use BMS 5-157 tape instead of the non-compliant BMS 5-149 

tape. This change gives operators new instructions to apply BMS 8-300 insulation to the Environmental Control 

System (ECS) ducts with BMS 5-157 tape. The BMS 5-157 tape must fully cover the BMS 8-300 insulation. The 

new configuration for the ECS duct insulation meets the flammability requirements of 14CFR 25.856(a), 

Amendment 111. Airplanes that have the intent of this service bulletin done after September 02, 2005, must 

satisfy the new requirements by fully covering the brown hypalon cover of the BMS 8-300 insulation with BMS 

5-157 tape.

Changes to this service bulletin include:

— Paragraph 2.C.2. Parts and Material Supplied by the Operator has changed to remove the reference to 

BMS 5-149 tape and to add reference to BMS 5-157 tape, Type 1, Class 1, Grade B, Form 1, Composition 

MPVF (Metallized Polyvinyl Fluoride) tape.

— Paragraph 2.C.2. Parts and Material Supplied by the Operator has changed to remove the reference to 

BMS 5-7 Type 1 adhesive.

— Appendix A. is changed to give the new instructions to install the BMS 8-300 insulation using BMS 5-157 

tape.

— Airplane RD233 is moved from Group 2 to Group 3.

— Duct assembly part number 65B41764-1026 has been changed to 654B41764-2026. The 65B41764-2026 

is the same as the 65B41764-1026, except that it is wrapped with BMS 5-157 tape. 

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.
 

August 21, 2003

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BOEING SERVICE BULLETIN 747-21A2422

REVISION HISTORY

Original Issue: August 21, 2003

Revision 1: January 20, 2005

Revision 2: November 16, 2006
August 21, 2003

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Commercial

Airplane

Group 747

Service Bulletin

Number: 747-21A2422 Summary

Date: August 21, 2003

Revision 2: November 16, 2006

ATA System: 2122

SUBJECT: AIR CONDITIONING - Distribution - Duct Insulation, BMS 8-39 Foam, Replacement

CONCURRENT REQUIREMENTS

None

BACKGROUND

Airplanes affected by this service bulletin have a single duct assembly installed that does not meet the 

flammability requirements of Federal Aviation Regulation, FAR 25.853, relating to the 12-second vertical burn 

requirement. This is a result of the combination of BMS 8-39 foam insulation and BAC 5010, Type 98, adhesive. 

This combination of materials may present a potential fire hazard.

This service bulletin provides instructions to replace the existing duct with a new duct assembly. Instructions 

are also provided to rework the duct assembly by removing the existing BMS 8-39, polyurethane foam 

insulation, and replacing it with BMS 8-300, polyimide foam insulation.

There have been no reports of this duct burning on 747 airplanes.

Boeing Service Related Problem (SRP) 747 SRP-21-0143 is related to this service bulletin.

ACTION (PRR 85901-18RS, Part B and C)

Replace or rework duct assembly, in the forward, lower, cargo bay. Perform functional test.

EFFECTIVITY

Refer to Paragraph 1.A.1. Airplanes, for the list of the affected airplanes.

COMPLIANCE

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

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

mandatory.

INDUSTRY SUPPORT INFORMATION

Upon request, one replacement duct for each affected airplanes will be provided at no-charge. Man-hour 

reimbursement will be provided for airplanes in warranty as of April 20, 2001. Please refer to Paragraph 2.B., 

Industry Support Information.
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MANPOWER

MATERIAL INFORMATION

Boeing Supplied Parts

Operator Supplied Materials

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

Total Task-Hours Elapsed Time (Hours)

3.75 2.25

REWORK OR REPLACE

DUCT ASSEMBLY

FORWARD CARGO DOOR

V62344
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Commercial

Airplane

Group 747

Service Bulletin

Number: 747-21A2422

Date: August 21, 2003

Revision 2: November 16, 2006

ATA System: 2122

SUBJECT: AIR CONDITIONING - Distribution - Duct Insulation, BMS 8-39 Foam, Replacement

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. An equivalent change is on subsequent 

production airplanes. Refer to PRR 85901-18RS (Part B and C) for data about this change.

Airplane models:

747-100 747-100B 747-200B 747-200C

747-200F 747-300 747-400F 747SP

747SR

IDENTIFICATION BY CUSTOMER, CUSTOMER CODE, GROUP AND VARIABLE NUMBER

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

2 RB681–RB682

AERO CONTROLS (AEO)

2 RA722–RA723

GROUP CONFIGURATION DESCRIPTION

1 - Duct Assembly 65B41764-2 installed in 

production.

2 - Duct Assembly 65B41764-5 installed in 

production.

3 - Duct Assembly 65B41764-6 installed in 

production.

4 - Duct Assembly 65B41764-6 installed in 

production.
 

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BOEING SERVICE BULLETIN 747-21A2422

AEROLINEAS ARGENTINAS (ARG)

2 RD122–RD127

AFRICA UNITED HOLDING CO. (UHD)

2 RB010

AFX (AXL)

2 RD201

3 RR221

AGES AIRCRAFT SALES & LEASING (AGJ)

2 RB004

AIR ATLANTA ICELANDIC (AID)

2 RD141 RD414 RD647–RD648 RD771

RS211 RS222 RS233 RS235

RS237

3 RR332

AIR CANADA (ACN)

2 RA749–RA750 RD531

AIR CHINA (BEJ)

2 RD781

AIR FRANCE (AFA)

2 RD657–RD658 RD721–RD722

3 RR306

AIR GULF FALCON (GFG)

2 RA535 RA537

AIR INDIA (AIN)

2 RA729 RA731

AIR PLUS COMET (PLD)

2 RD053

AIR PULLMANTUR (PUL)

2 RD655

AIR UNIVERSAL (UVL)

2 RD649

ALBARAKA (AAB)

1 RB102

ALL NIPPON AIRWAYS (ANA)

2 RB691–RB693 RB695

AMERICAN AIRLINES (AAL)

2 RA266
 

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BOEING SERVICE BULLETIN 747-21A2422

ARKIA ISRAELI AIRLINES (ARK)

1 RA253

ASIANA AIRLINES (AAR)

4 RM861 RR746–RR748

ATLAS AIR (TLS)

2 RB684 RD361–RD366 RD411 RD641–RD642

RD646 RD691–RD692 RD752–RD753

3 RJ333 RR301 RR303

4 RM891–RM899 RM901–RM903

AVIATION EXPOSURE MANAGEMENT (EXU)

2 RD131–RD132 RD143

BAHRAIN ROYAL FLIGHT (BHR)

3 RG009

BANC OF AMERICA LEASING (SBC)

1 RA106

2 RD001–RD002

BOEING (TBC)

3 RR222–RR223

BOEING AIRCRAFT HOLDING CO. (BHC)

2 RD181 RD451–RD454

BOEING CAPITAL CORPORATION (ZMF)

2 RB687 RD072

3 RJ132 RR201

BOEING WICHITA MOD CENTER (WMC)

2 RD455

C.A.L. CARGO AIR LINES (CRG)

3 RJ331–RJ332

C.I.T. LEASING CORPORATION (TCI)

2 RB011 RD047

CARGAIR (CGL)

2 RD203

CARGOLUX AIRLINES (CLX)

4 RM881–RM885 RR701 RR721–RR724

CATHAY PACIFIC AIRWAYS (CAT)

2 RD358 RD581–RD583

3 RR531

4 RM856 RR951–RR952
 

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BOEING SERVICE BULLETIN 747-21A2422

CHINA AIRLINES (CHI)

4 RL411–RL413

DUBAI AIR WING (DAW)

2 RD622 RG191

EL AL ISRAEL AIRLINES (ELA)

2 RD442

3 RJ152 RR225–RR226

EUROPEAN AVIATION AIR CHARTER (EUL)

2 RD135–RD138

EVA AIR (EVA)

4 RL401

EVERGREEN INTERNATIONAL A/L (EVR)

2 RB604 RB607 RD004 RD041–RD043

3 RA028 RA631 RA633 RJ131

RJ133

EXPORT RESTRICTED AIRPLANES (YWV)

1 RA101–RA103 RA112 RA161–RA162

2 RA163 RD513 RG171

3 RR001–RR004

4 RM852 RR855

GA TELESIS (GTG)

2 RG163

GE (GEC)

1 RA016

GE CAPITAL CORPORATION (GEF)

1 RA007 RA013 RA027

GLOBAL AIR LEASING (GAO)

2 RG164

GLOBAL PEACE INITIATIVE (GPI)

2 RG174

GRACE CATHEDRAL INC. (GCI)

2 RG193

GUGGENHEIM AVIATION PARTNERS (GPR)

2 RB697

IBERIA AIRLINES (IBE)

2 RD431–RD435

INTERNATIONAL AIR LEASES (IAL)

2 RB006
 

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BOEING SERVICE BULLETIN 747-21A2422

IRAN AIR (IRN)

2 RB711 RD681–RD682 RG101–RG104

IRAQI AIRWAYS (IRQ)

2 RG095 RG172

3 RJ301–RJ303

JAL INTERNATIONAL (JAL)

2 RA546 RA548 RD055 RD222–RD226

RS251–RS253

3 RR264–RR265 RR361–RR362

JET AERO HOLDINGS (JHD)

2 RG122

JUMBO JET LEASING (JJL)

2 RA526 RA532–RA534 RA539

KABO AIR (KAB)

1 RA305

2 RA316 RA560 RB008 RD121

KALITTA AIR (KAC)

2 RA401–RA402 RA524 RA545 RA547

RA635 RA913 RD054 RD082–RD083

RD221 RD571 RD621 RD623

3 RB605 RR261–RR262 RR501 RR521

KLM - ROYAL DUTCH AIRLINES (KLM)

2 RD382 RD607

KOREAN AIR (KAL)

4 RM871–RM873 RR861–RR862

KUWAIT AIRWAYS (KUW)

2 RD202 RD204

L-3 COMMUNICATIONS (LCS)

2 RD352

LOGISTIC AIR, INC. (LGA)

1 RA015

2 RA217 RB722–RB723

MARTINAIR HOLLAND (MTH)

2 RD601

MK AIRLINES (MKA)

2 RD441 RD561

3 RR022–RR023 RR224 RR336 RR421

NASA (NAS)

2 RA908 RB601
 

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BOEING SERVICE BULLETIN 747-21A2422

NEA HOLDINGS, INC. (NEA)

2 RB001 RD045–RD046

NIPPON CARGO AIRLINES (NCA)

3 RB696 RD233 RD461 RR551

NORTHWEST AIRLINES (NWA)

2 RA370–RA373 RD056–RD057 RD241–RD243 RD251–RD259

RS701–RS702

3 RR005 RR341–RR345 RR503

OCEAN AIRLINES (OCE)

3 RR202–RR203

OMAN ROYAL FLIGHT (RFO)

2 RG161

OMEGA AIR HOLDINGS (OMC)

2 RB694 RD142 RD144 RD412

ORIENT THAI AIRLINES (OTH)

2 RA528 RA540 RA543–RA544 RD516

RS712

PAKISTAN INT'L AIRLINES (PIA)

2 RD104 RD701–RD702

PHUKET AIRLINES (PHK)

2 RD381 RD421–RD424 RD605 RS711

POLAR AIR CARGO (PAO)

2 RA910

3 RR504

4 RL651

PRATT & WHITNEY ENGINE SERVICE (PWE)

2 RG213

QANTAS (QAN)

2 RS271–RS272

ROYAL AIR MAROC (RAM)

2 RD671

SATAIR (SAI)

2 RD383 RD606

SAUDI ARABIAN AIRLINES (SVA)

2 RB741–RB746 RB748

3 RH121
 

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BOEING SERVICE BULLETIN 747-21A2422

SAUDI ROYAL FLIGHT (SRF)

2 RH101 RS699

3 RH122

SINGAPORE AIRLINES (SIA)

4 RM851 RM853 RR851–RR854 RR856

SKY EXPRESS S.A. (SXS)

2 RD592

SOUTH AFRICAN AIRWAYS (SAA)

2 RG123 RG125 RS212 RS232

RS236

SOUTHERN AIR (SOF)

2 RD182 RD272 RD602 RD604

RD643

3 RR302 RR304–RR305

SUO1 (UO1)

2 RB013–RB016

SYRIANAIR (SYR)

2 RG141–RG142

TESIS AVIATION ENTERPRISE (TEV)

2 RA784

TRADEWINDS AIRLINES (TWN)

2 RA726 RD052 RD426

TRANSAERO AIRLINES (TRX)

2 RD356 RD471–RD475

TRANSATLANTIC INTL AIRLINES (TIB)

2 RG173

UPS (UPS)

2 RA033 RA912 RA915–RA916 RD051

RD058–RD059 RD593

3 RA026 RA029 RA902

US AIR FORCE (USF)

4 RM911

USRA (USP)

3 RG091

VIRGIN ATLANTIC AIRWAYS (VAA)

2 RD357
 

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BOEING SERVICE BULLETIN 747-21A2422

VOLGA-DNEPR AIRLINES (VDA)

2 RD751

3 RR561

WHIRLPOOL FINANCIAL CORP. (ZZW)

2 RB005

WINGS WORLD WIDE (WWW)

2 RG221–RG222

WORLDWIDE AIRCRAFT HOLDING CO. (WAH)

3 RG008

YEMENIA (YEM)

2 RG162

IDENTIFICATION BY VARIABLE NUMBER

Variable Group

RA001–RA025 1

RA026 3

RA027 1

RA028–RA029 3

RA030–RA034 2

RA101–RA114 1

RA161–RA162 1

RA163–RA164 2

RA201–RA203 1

RA216–RA217 2

RA245–RA246 2

RA251–RA255 1

RA256–RA266 2

RA301–RA305 1

RA307–RA318 2

RA351–RA360 1

RA370–RA373 2

RA401–RA418 2

RA501–RA502 1

RA521–RA523 1

RA524–RA528 2

RA532–RA548 2

RA551–RA552 1

RA559–RA561 2

RA581–RA582 1
 

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BOEING SERVICE BULLETIN 747-21A2422

RA585 2

RA601–RA602 1

RA631 3

RA632 1

RA633 3

RA634–RA635 2

RA652 2

RA672–RA677 2

RA701–RA702 2

RA721–RA731 2

RA741 1

RA742–RA745 2

RA749–RA750 2

RA761 1

RA762 2

RA781–RA784 2

RA901 2

RA902 3

RA903–RA916 2

RB001–RB016 2

RB041–RB043 1

RB044 2

RB071–RB075 2

RB101–RB102 1

RB601–RB604 2

RB605 3

RB606–RB607 2

RB681–RB695 2

RB696 3

RB697 2

RB711 2

RB721–RB723 2

RB741–RB748 2

RD001–RD004 2

RD021–RD022 2

RD041–RD059 2

RD071–RD072 2

RD081–RD083 2

RD091–RD092 2

Variable Group
 

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BOEING SERVICE BULLETIN 747-21A2422

RD101–RD104 2

RD121–RD127 2

RD131–RD144 2

RD171–RD172 2

RD181–RD183 2

RD201–RD204 2

RD221–RD226 2

RD233 3

RD241–RD243 2

RD251–RD259 2

RD271–RD272 2

RD351–RD358 2

RD361–RD366 2

RD381–RD383 2

RD411–RD414 2

RD421–RD426 2

RD431–RD435 2

RD441–RD442 2

RD451–RD455 2

RD461 3

RD471–RD475 2

RD513–RD519 2

RD531–RD533 2

RD551 2

RD561 2

RD571 2

RD581–RD583 2

RD591–RD593 2

RD601–RD607 2

RD621–RD623 2

RD641–RD649 2

RD651–RD658 2

RD661 2

RD671 2

RD681–RD682 2

RD691–RD692 2

RD701–RD702 2

RD721–RD722 2

RD741–RD742 2

Variable Group
 

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RD751–RD753 2

RD761 2

RD771 2

RD781 2

RE001 2

RG001–RG009 3

RG091 3

RG095 2

RG101–RG104 2

RG121–RG126 2

RG141–RG142 2

RG161–RG164 2

RG171–RG174 2

RG191–RG193 2

RG211–RG213 2

RG221–RG222 2

RH101 2

RH111–RH112 2

RH121–RH122 3

RJ131–RJ133 3

RJ151–RJ152 3

RJ301–RJ303 3

RJ331–RJ333 3

RL401 4

RL411–RL413 4

RL651 4

RM851–RM853 4

RM856 4

RM861 4

RM871–RM873 4

RM881–RM885 4

RM891–RM899 4

RM901–RM903 4

RM911 4

RR001–RR005 3

RR021–RR023 3

RR031 3

RR201–RR203 3

RR221–RR226 3

Variable Group
 

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2. Spares Affected

Examine your spares supply for the parts or components identified in Paragraph 2.C., Parts 

Necessary for Each Airplane. If any parts or components are found, refer to Paragraph 2.C. for 

the recommended use.

B. Concurrent Requirements

None

RR261–RR265 3

RR301–RR306 3

RR331–RR332 3

RR336 3

RR341–RR345 3

RR361–RR362 3

RR421–RR422 3

RR501–RR504 3

RR521 3

RR531 3

RR551 3

RR561 3

RR701 4

RR721–RR724 4

RR746–RR748 4

RR851–RR856 4

RR861–RR862 4

RR951–RR952 4

RS201 2

RS211–RS212 2

RS221–RS222 2

RS231–RS237 2

RS251–RS253 2

RS271–RS272 2

RS291 2

RS699 2

RS701–RS702 2

RS711–RS712 2

Variable Group
 

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C. Reason

Airplanes affected by this service bulletin have a single duct assembly installed that does not meet the 

flammability requirements of Federal Aviation Regulation, FAR 25.853, relating to the 12-second 

vertical burn requirement. This is a result of the combination of BMS 8-39 foam insulation and BAC 

5010, Type 98, adhesive. This combination of materials may present a potential fire hazard.

This service bulletin provides instructions to replace the existing duct with a new duct assembly. 

Instructions are also provided to rework the duct assembly by removing the existing BMS 8-39, 

polyurethane foam insulation, and replacing it with BMS 8-300, polyimide foam insulation.

There have been no reports of this duct burning on 747 airplanes.

Revision 1 is sent to update the effectivity from the initial release of this service bulletin. Airplanes 

RA026 and RA029 have been removed from Group 1 and added to Group 3. These airplanes were 

originally fitted with 65B41764-6 Ducts. 

Airplanes RA028, RA631, and RA633 have been removed from Group 1 and added to Group 3. These 

airplanes were modified and fitted with 65B41764-6 ducts.

Airplanes RA902, RB605, RB696 and RD461 have been removed from Group 2 and added to Group 

3. These airplanes were originally fitted with 65B41764-6 Ducts. 

 Airplane RD233 was omitted from the initial release of this service bulletin and has now been included 

in Group 2.

Changes to this service bulletin include:

— Paragraph 2.A., Material - Price and Availability - part quantities for Groups 2, 3 and 4 airplanes 

have been revised.

— Paragraph 2.C.2., Material - Parts Supplied by the Operator - Fiberglass Tape, Style 116, per 

BMS 9-3R, was added to the table.

— Appendix B: BAC 5412 Method VII - Bonding Duct Joints - revised to include a change of 

supplier.

Revision 02 is sent to give operators approval to use BMS 5-157 tape instead of the non-compliant 

BMS 5-149 tape. This change gives operators new instructions to apply BMS 8-300 insulation to the 

Environmental Control System (ECS) ducts with BMS 5-157 tape. The BMS 5-157 tape must fully 

cover the BMS 8-300 insulation. The new configuration for the ECS duct insulation meets the 

flammability requirements of 14CFR 25.856(a), Amendment 111. Airplanes that have the intent of this 

service bulletin done after September 02, 2005, must satisfy the new requirements by fully covering 

the brown hypalon cover of the BMS 8-300 insulation with BMS 5-157 tape.

Changes to this service bulletin include:

— Paragraph 2.C.2. Parts and Material Supplied by the Operator has changed to remove the 

reference to BMS 5-149 tape and to add reference to BMS 5-157 tape, Type 1, Class 1, Grade 

B, Form 1, Composition MPVF (Metallized Polyvinyl Fluoride) tape.

— Paragraph 2.C.2. Parts and Material Supplied by the Operator has changed to remove the 

reference to BMS 5-7 Type 1 adhesive.

— Appendix A. is changed to give the new instructions to install the BMS 8-300 insulation using 

BMS 5-157 tape.

— Airplane RD233 is moved from Group 2 to Group 3.
 

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— Duct assembly part number 65B41764-1026 has been changed to 654B41764-2026. The 

65B41764-2026 is the same as the 65B41764-1026, except that it is wrapped with BMS 5-157 

tape. 

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

Effectivity paragraph for changes.

Boeing Service Related Problem (SRP) 747 SRP-21-0143 is related to this service bulletin.

D. Description

Replace or rework duct assembly, in the forward, lower, cargo bay. Perform functional test.

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

01 of this service bulletin, if accomplished after September 02, 2005. If the intent of this Revision 02 

was accomplished after September 02, 2005, then no more work is required.

The airplane effectivity is divided into four groups. The difference between the airplane groups is 

limited to the part number installed on the airplane and the specification requirements for reinstalling 

the new duct assembly.

The changes in this service bulletin will not change the Central Maintenance Computer System 

(CMCS).

E. Compliance

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

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

this service bulletin mandatory.

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.

G. Manpower

The table below shows an estimate of the task-hours necessary to do this change for each airplane. 

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

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
 

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— Time to make the parts

— Time to find the tools.

H. Weight and Balance Changes

None

I. Electrical Load Data

Not applicable

J. References

1. Existing Data:

a. Engineering Change Memo PRR 85901-18RS, Part B and C

b. 747 Aircraft Maintenance Manual (AMM) 25-52-01

c. 747 Illustrated Parts Catalog (IPC) 21-22-06

d. 747-100/200/300 Aircraft Maintenance Manual (AMM) 21-23-01

e. 747-400 Aircraft Maintenance Manual (AMM) 21-23-02

f. Service Related Problem (SRP) 747 SRP-21-0143

g. Boeing Standard Overhaul Practices Manual (SOPM) 20-30-03, 20-50-12, 20-60-01

2. Data supplied with this Service Bulletin:

None

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

These drawings were used to prepare this service bulletin. These drawings are not necessary 

to make the specified changes, and are not supplied with this service bulletin. These drawings 

may not be applicable to all airplane configurations or operators.

Task Number of Persons Task-Hours Elapsed Time (Hours)

Open Access 2 1.5 0.75

Change 1 0.75 0.75

Close Access 2 1.5 0.75

TOTAL FOR EACH AIRPLANE 3.75 2.25

Drawing Number Title

65B40176 Duct Installation - Flight Deck Air Conditioning, Section 42

217U1003 Duct Installation - Forward E/E Cooling

Supply
 

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4. Process Data:

Boeing Process Specifications referred to on the drawings are not given in this service bulletin 

since these procedures are frequently used as standard shop practices.

The procedures shown that are not frequently used and are shown in Appendix B and C.

K. Publications Affected

L. Interchangeability and Intermixability of Parts

Refer to Paragraph 2.C., Parts Necessary For Each Airplane, for interchangeability and intermixability 

information.

Publication Chapter-Section

747 Illustrated Parts Catalog 747 IPC 21-22-06
 

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2. MATERIAL INFORMATION

A. Material - Price and Availability

Replacement ducts for all affected airplanes will be provided at no-charge upon request. Boeing can 

supply the parts shown in Paragraph 2.C., Parts Necessary For Each Airplane as shown below. If 

there is a limit in the quantity (QTY) of parts, a supply sequence is given by Spares.

The parts are subject to the terms and conditions of the Boeing standard purchase order 

acknowledgment.

Reference this service bulletin and submit your purchase order by one of the methods that follow: 

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

2. Fax to (206) 662-7145

3. Spares Customer Support - MC 36-65

Boeing Spares Department

P.O. Box 3707

Seattle, Washington 98124-2207 USA

B. Industry Support Information

Upon request, one replacement duct for each affected airplane will be provided at no-charge, 

regardless of warranty status. Task-hour reimbursement will be provided for airplanes in warranty as 

of April 20, 2001. Send a purchase order for the part to Boeing Spares and a claim for labor 

reimbursement to Boeing Warranty. Please refer to this service bulletin number and reference the 

airplane variable number in your purchase orders and labor reimbursement claim.

Part Number Name Airplane Group Date QTY

65B41764-1002 Duct Assembly (Group 1 Airplanes) April 16, 2002 20

65B41764-1005 Duct Assembly (Group 2 Airplanes) May 14, 2002 90

65B41764-2026 Duct Assembly (Group 3 and Group 4 Airplanes) May 28, 2002 79
 

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C. Parts Necessary For Each Airplane

1. Kits/Parts:

The operator has the option to do this change with one of the following two methods.

a. Remove and discard the affected duct and replace with a new duct provided by Boeing.

b. Remove, rework, partmark, then install the reworked duct.

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

duct assembly or one reworked duct assembly is required for each airplane.

QTY Part Number Name Note

1 65B41764-1002 Duct Assembly (Group 1 Airplanes) (a)

1 65B41764-1005 Duct Assembly (Group 2 Airplanes) (a)

1 65B41764-2026 Duct Assembly (Group 3 and Group 4 Airplanes)

(a) If this duct is installed, it must be wrapped with BMS 5-157 tape as given in Appendix A. 
 

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2. Parts and Materials Supplied by the Operator:

NOTE: For the re-attachment of a new or reworked duct assembly there are several options

which are outlined in your applicable figure. For these additional material requirements

see the following specifications: SOPM 20-50-12 Type 44; SOPM 20-50-12, Type 117;

this service bulletin, Appendix B (BAC 5412 Method VII), and Appendix C (BAC 5412

Method VIII).

NOTE: The materials listed below, except for the tie strap, are for reworking the duct assembly

by applying the new insulation and wrapping the insulation with BMS 5-157 tape.

3. Parts Modified and Reidentified:

The parts shown below are changed as shown in this service bulletin. The quantity (QTY) is the 

number of parts changed on each airplane.

QTY Part Number {Specification} Name

1 sheet BMS 8-300 Type 2, Grade 0.6 or Grade 5, with

thickness of 0.375 inches, 4 feet X 8 feet sheet

Polyimide Foam Insulation (a) (b)

(e)

As required BMS 5-157, Type 1, Class 1, Grade B, Form 1,

Composition MPVF (Metallized polyvinyl Fluoride)

Widths: 2 inch, 3 inch and 12 inch

Tape (c) (e)

3 ounces BMS 5-7, Type 2 Adhesive (a) (e)

6 Feet Style 116 Per BMS 9-3R, Type C, Class 7, slit and

sealed, 3 inches nominal width

Fiberglass Tape (a) (e)

1 BACS38K6 Tie Strap

(a) These materials are not required if the existing duct is being replaced with a new duct assembly.

(b) Vendor Contact Information:

Jehier SA

Route DE Saint-Lezin

F-49120

Chemille, France

 or Boyd Corporation

6236 N.E. 87th Avenue

Portland, OR 97220, USA

(c) Tape BMS 5-157, Type 1, Class 1, Grade B, Form 1, Composition MPVF (Metallized Polyvinyl Fluoride), replaces tape BMS 5-149, Type 11, Class 1 or 2, Grade C, Form 1.

(d) Vendor Contact Information:

E&H Laminating and Slitting Company

138 Grand Street

Paterson, NJ 07501, USA

Telephone (973) 345-3224

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

data.

Existing Part 

Number QTY Name New Part Number Notes

65B41764-2 1 Duct Assembly 65B41764-1002 (a) (b)

65B41764-5 1 Duct Assembly 65B41764-1005 (a) (b)
 

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4. Parts Removed and Not Replaced:

None.

D. Parts Necessary to Change Spares

See Paragraph 2. C. 2. Parts and Materials Supplied by the Operator, for the material required to 

rework ducts in the operators spares supply.

E. Special Tooling - Price and Availability

None

F. Special Tooling Necessary to do this Service Bulletin

No special tools or equipment are necessary to do the change in this service bulletin. But, 

maintenance and overhaul tools in the manuals given in Paragraph 1.J., References, can be 

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

65B41764-6 1 Duct Assembly 65B41764-2026 (a) (b)

(a) Make the change given in this service bulletin.

(b) This is the part number after the change given in this service bulletin.

Existing Part 

Number QTY Name New Part Number Notes
 

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BOEING SERVICE BULLETIN 747-21A2422

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. Reference 747-100/200/300 AMM 21-23-01and 747-400 AMM 21-23-02, for information 

to repair damaged ducts.

2. If the duct assembly is reworked, the instructions are given in Appendix A.

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

— Linear dimensions are in inches

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

minus 0.03 inch

— Torque limits to tighten nuts and bolts are given in 747 Structural Repair Manual, 

Chapter 51.

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

B. WORK INSTRUCTIONS

1. Get access to the affected duct assembly as shown in Figure 1.

2. Remove, then rework as given in Appendix A or replace the affected duct assembly as follows:

— Group 1 airplanes do Figure 2.

— Group 2 airplanes do Figure 3.

— Group 3 airplanes do Figure 4.

— Group 4 airplanes do Figure 5.

3. Do the following functional test to determine that the duct assembly has been installed correctly 

and does not leak.

a. Pressurize the affected duct assembly by running at least two of the air conditioning packs, 

(or use a suitable equivalent ground cart). Apply power to the recirculation fans, (If the 

airplane is in the GROUND MODE, only the upper recirculation fans will operate).

b. For the replacement duct, verify by sound and feel that there are no concentrated leaks at 

the duct joints. Small leaks are permitted. Large or concentrated leaks must be repaired.

— (A concentrated or large leak is defined as a jet or stream of air that can be felt on the 

palm of the hand, three to four inches from the surface of the duct).

4. Install the forward cargo compartment panels removed in Figure 1. Reference 747 AMM 

25-52-01.

5. Put the airplane back to a serviceable condition.
 FIGURE 1: DUCT ACCESS, ALL AIRPLANE GROUPS

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FIGURE 1: DUCT ACCESS, ALL AIRPLANE GROUPS

4

FORWARD CARGO DOOR

3

2

1

V62348

LOOKING AFT

FORWARD CARGO COMPARTMENT

(SHEET 1 OF 2)
 FIGURE 1: DUCT ACCESS, ALL AIRPLANE GROUPS

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

The QTY numbers shown below are the numbers of parts necessary for one airplane.

STEP TASK NAME REFERENCES QTY NOTES

1 Remove Sidewall Panel 747 AMM 25-52-01 1 -

2 Remove Ceiling Panel - 1 -

3 Remove Bulkhead Panel - 1 -

4 Identify Duct Assembly 65B41764-2 1 Group 1 Airplanes

65B41764-5 1 Group 2 Airplanes

65B41764-6 1 Group 3 and Group 4 Airplanes

(SHEET 2 OF 2)
 FIGURE 2: DUCT ASSEMBLY REWORK, GROUP 1 AIRPLANES

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FIGURE 2: DUCT ASSEMBLY REWORK, GROUP 1 AIRPLANES

6

SEE A

TYPICAL VIEW

A

4

5

1 2 3

1000

STA

FORWARD CARGO DOOR

FWD

UP

V62351

(SHEET 1 OF 2)
 FIGURE 2: DUCT ASSEMBLY REWORK, GROUP 1 AIRPLANES

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

The QTY numbers shown below are the numbers of parts necessary for one airplane.

CAUTION: THE FORWARD DUCT CONNECTION IS JOINED WITH ADHESIVE. USE CARE WHEN

SEPARATING THIS CONNECTION AS NOT TO DAMAGE EITHER DUCT ASSEMBLY.

STEP TASK NAME PART NUMBER QTY NOTES

1 Remove/

Discard or

Rework

Duct Assembly 65B41764-2 1 Reference Appendix A for rework instructions.

2 Mark Part Number 65B41764-1002 1 Part marking required only if you

are reworking the existing duct

assembly.

3 Install

(New) or

Reworked

Duct Assembly 65B41764-1002 1 -

4 Install Strap BACS38K6 1 -

5 Attach Duct Joint - - Reference procedure in Appendix C, (BAC 5412, Method VIII).

6 Attach Duct Joint - - Reference BSOPM 20-50-12,

Type 44 or Type 117.

(SHEET 2 OF 2)
 FIGURE 3: DUCT ASSEMBLY REWORK, GROUP 2 AIRPLANES

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FIGURE 3: DUCT ASSEMBLY REWORK, GROUP 2 AIRPLANES

FORWARD CARGO DOOR

STA

1000

1 2 3

5

4

A

TYPICAL VIEW

SEE A

6

FWD

UP

V62402

(SHEET 1 OF 2)
 FIGURE 3: DUCT ASSEMBLY REWORK, GROUP 2 AIRPLANES

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

The QTY numbers shown below are the numbers of parts necessary for one airplane.

CAUTION: THE FORWARD DUCT CONNECTION IS JOINED WITH ADHESIVE. USE CARE WHEN

SEPARATING THIS CONNECTION AS NOT TO DAMAGE EITHER DUCT ASSEMBLY.

STEP TASK NAME PART NUMBER QTY NOTES

1 Remove/

Discard or

Rework

Duct Assembly 65B41764-5 1 Reference Appendix A for rework instructions.

2 Mark Part Number 65B41764-1005 1 Part marking required only if you

are reworking the existing duct

assembly.

3 Install;

(New) or

Reworked

Duct Assembly 65B41764-1005 1 -

4 Install Strap BACS38K6 1 -

5 Attach Duct Joint - - Reference procedure in Appendix C, (BAC 5412, Method VIII).

6 Attach Duct Joint - - Reference BSOPM 20-50-12,

Type 44 or Type 117.

(SHEET 2 OF 2)
 FIGURE 4: DUCT ASSEMBLY REWORK, GROUP 3 AIRPLANES

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FIGURE 4: DUCT ASSEMBLY REWORK, GROUP 3 AIRPLANES

FORWARD CARGO DOOR

STA

1000

1 2 3

5

4

A

TYPICAL VIEW

SEE A

6

FWD

UP

V62403

(SHEET 1 OF 2)
 FIGURE 4: DUCT ASSEMBLY REWORK, GROUP 3 AIRPLANES

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

The QTY numbers shown below are the numbers of parts necessary for one airplane.

CAUTION: THE FORWARD DUCT CONNECTION IS JOINED WITH ADHESIVE. USE CARE WHEN

SEPARATING THIS CONNECTION AS NOT TO DAMAGE EITHER DUCT ASSEMBLY.

STEP TASK NAME PART NUMBER QTY NOTES

1 Remove/

Discard or

Rework

Duct Assembly 65B41764-6 1 Reference Appendix A for rework instructions.

2 Mark Part Number 65B41764-2026 1 Part marking required only if you

are reworking the existing duct

assembly.

3 Install

(New) or

Reworked

Duct Assembly 65B41764-2026 1 -

4 Install Strap BACS38K6 1 -

5 Attach Duct Joint - - Reference procedure in Appendix C, (BAC 5412, Method VIII).

6 Attach Duct Joint - - Reference BSOPM 20-50-12,

Type 44 or Type 117.

(SHEET 2 OF 2)
 FIGURE 5: DUCT ASSEMBLY REWORK, GROUP 4 AIRPLANES

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FIGURE 5: DUCT ASSEMBLY REWORK, GROUP 4 AIRPLANES

FORWARD CARGO DOOR

STA

1000

1 2 3

5

4

A

TYPICAL VIEW

SEE A

6

FWD

UP

V62404

(SHEET 1 OF 2)
 FIGURE 5: DUCT ASSEMBLY REWORK, GROUP 4 AIRPLANES

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

The QTY numbers shown below are the numbers of parts necessary for one airplane.

CAUTION: THE FORWARD DUCT CONNECTION IS JOINED WITH ADHESIVE. USE CARE WHEN

SEPARATING THIS CONNECTION AS NOT TO DAMAGE EITHER DUCT ASSEMBLY.

STEP TASK NAME PART NUMBER QTY NOTES

1 Remove/

Discard or

Rework

Duct Assembly 65B41764-6 1 Reference Appendix A for rework instructions.

2 Mark Part Number 65B41764-2026 1 Part marking required only if you

are reworking the existing duct

assembly.

3 Install

(New) or

Reworked

Duct Assembly 65B41764-2026 1 -

4 Install Strap BACS38K6 1 -

5 Attach Duct Joint - - Reference procedure in Appendix B, (BAC 5412, Method VII).

Also can use optional procedure

BSOPM 20-50-12, Type 117.

6 Attach Duct Joint - - Reference BSOPM 20-50-12,

Type 70, 79, or 117.

(SHEET 2 OF 2)
 APPENDIX A: PROCESS DATA - APPLICATION OF BMS 8-300 BY TAPING WITH BMS 5-157 TAPE

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APPENDIX A: PROCESS DATA - APPLICATION OF BMS 8-300 BY TAPING WITH BMS 5-157 TAPE

NOTE: Reference 747-100/200/300 AMM 21-23-01 and 747-400 AMM 21-23-02, for information to repair

damaged ducts.

1. Remove existing insulation from duct assembly. Apply new insulation using the following information. 

NOTE: When insulation is removed, some residual adhesive and foam insulation may remain attached to

the duct assembly. Small amounts are permissible. If there is an excessive amount of insulation

still attached to the duct, it can be removed with a scotch-brite pad. Surface cleaning of the duct

is not required.

2. Insulation material shall be in accordance with BMS 8-300, Type II, Grade 0.6 or Grade 5, 0.375 inch 

thickness.

3. Insulation blanket tape shall be in accordance with BMS 5-157, Type 1, Class 1, Grade B, Form 1, 

Composition MPVF (Metallized Polyvinyl Fluoride), 2 inch, 3 inch, or 12 inch widths.

NOTE: Tape BMS 5-157, Type 1, Class 1, Grade B, Form 1, Composition MPVF (Metallized Polyvinyl

Fluoride), replaces BMS 5-149, Type 11, Class 1 or 2, Grade C, Form 1. Do not use BMS 5-149

tape with BMS 8-300 insulation.

4. Install the insulation with the foam side against the duct surface. Where, due to size and shape of duct, 

more than one piece of insulation is required, individual pieces may be used. Use BMS 5-157 tape to 

secure the insulation in position.

5. If bonding is necessary to tack bond the insulation to the duct to maintain the position prior to tape 

application, refer to Boeing Standard Overhaul Practices Manual 20-50-12, Type 58, BMS 5-7, Type 2. A 

single coat of adhesive may be used in either one or both surfaces to be bonded. The following 

requirements shall also apply:

A. Lengthwise along duct - Adhesive bond lines of up to 2 inches wide are allowed, but no two bondlines 

may be closer than 12 inches centerline to centerline.

B. Bonding circumferentially - Adhesive bond lines of up to 2 inches wide around the duct, but no two 

bondlines may be closer than 12 inches centerline to centerline.

C. Spot tack bonding - 2 inch diameter (approximately) spots of adhesive may be used, but no two 

adhesives spots may be closer than 12 linear inches, center to center.

D. Edge bonding - Adhesive bondline may be up to 2 inches wide around the periphery of the insulation, 

or at seam or slit locations, and is acceptable on ducts or insulation of all sizes as necessary.

E. No overspray of adhesive is allowed outside the area to be covered by insulation. Minimize use of 

adhesives for bonding. Mask as required.

6. Use the tape in short strips (4 inches long or smaller), doubled over or double sided, at the discretion of the 

operator, to assist in holding the insulation in place.

7. The insulation shall be applied to within 3 inches of each end of the duct outlet or flange and to within 1 

inch of any spud or appendage as shown in the duct rework illustrations.
 APPENDIX A: PROCESS DATA - APPLICATION OF BMS 8-300 BY TAPING WITH BMS 5-157 TAPE

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8. Apply the tape such that no edge of the insulation blanket is exposed. In addition, apply tape to within 2 

inches (1.25 inch minimum) of each end of the duct outlet or flange, and in contact with any spud or 

appendage as shown in the duct rework illustrations.

9. Butt edges of insulation together within a gap of 0.10 inch to an overlap of 0.25 inch, and apply tape along 

seam to secure blanket.

10. Apply an additional circumferential or lengthwise wrap of BMS 5-157, Type 1, Class 1, Grade B, Form 1, 

Composition MPVF, tape that covers 100% of the brown hypalon surface of the BMS 8-300 insulation.

A. The BMS 5-157 tape can be installed in a spiral wrap or along the duct. Tape applied in a spiral wrap 

around the duct bends and on the flat areas is recommended.

B. Wider tape can be cut into thinner strips or different shapes to help fully cover the BMS 8-300 

insulation.

C. Make sure that there is a minimum of 1/8 inch overlap of the BMS 5-157 tape.

D. Avoid compression of the BMS 8-300 insulation.

E. Wrinkles in the tape are permitted if pinched together and contain no voids.

F. Tape can be applied to the insulation blanket before the insulation blanket is installed on the duct 

assembly.

G. Cut tape as needed to fit around air outlets, branches and insulation vent holes. 

11. All tolerances to be plus or minus 0.25 inch unless otherwise specified.

12. Partmark location should be within 6 inches of either end of the duct assembly, but not closer than 1 inch 

from the end of the duct, to prevent the part number from being covered by the sleeve during installation.
 APPENDIX A: PROCESS DATA - APPLICATION OF BMS 8-300 BY TAPING WITH BMS 5-157 TAPE

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INSULATION

BLANKET

BEAD OR FLANGE

F

D D

C

TAPE

C

3.00 TYPICAL

AT DUCT END

B

B

INSULATION

BLANKET

SEAM A

A

EDGE OF

INSULATION

BLANKET

EDGE OF

INSULATION

BLANKET

TAPE

EDGE OF

2.00 TYPICAL

EDGE OF TAPE

DUCT

TAPE

BLANKET

INSULATION

SEAM

BLANKET

INSULATION

SEAM

TAPE

INSULATION

BLANKET

DUCT

INSULATION

BLANKET

TAPE

AIR OUTLET

TYP

AIR OUTLET

TYP

TAPE

1.00 FROM

EDGE OF INSULATION

BLANKET

DUCT

TYP

AIR OUTLET

1.00 FROM

TAPE

AIR

OUTLET

TAPE

BLANKET

INSULATION

INSULATION END

OVERLAP AT

TAPE

A-A B-B

EXISTING

DUCT

EDGE OF

TAPE

0.125 MIN

TAPE

OVERLAP

BMS 5-157

TAPE BMS 8-300 INSULATION

EDGE OF TAPE

AT DUCT END

(1.25 MINIMUM)

V62353
 APPENDIX A: PROCESS DATA - APPLICATION OF BMS 8-300 BY TAPING WITH BMS 5-157 TAPE

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E E TYP

AIR OUTLET

INSULATION

BLANKET

EDGE OF

3.00

TAPE

4.00

TAPE

EDGE OF

DUCT

TYPICAL INSULATED DUCT ASSEMBLY

AS REQUIRED

AREA TO CLEAR OUTLET

TRIM TAPE IN OVERLAP

LENGTH AS

REQUIRED

BLANKET

INSULATION (2 LOCATIONS)

2.00

INSULATION

TAPE

AIR

OUTLET

INSULATION

BLANKET

INSULATION

SEAM

BLANKET

EDGE OF

TAPE

1.00 FROM

DUCT

BLANKET

WITH OUTLET AT END

TYPICAL ARRANGEMENT AT END OF DUCT

C-C

D-D

2.00 TYPICAL

(1.25 MINIMUM)

V62354
 APPENDIX A: PROCESS DATA - APPLICATION OF BMS 8-300 BY TAPING WITH BMS 5-157 TAPE

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BOEING SERVICE BULLETIN 747-21A2422

ROTATED 35 DEGREES CW

TYPICAL ARRANGEMENT FOR ALL

90 DEGREE AIR OUTLETS EXCEPT AS NOTED

INSULATION BLANKET

INSULATION BLANKET

AIR OUTLET

AIR OUTLET

TAPE

TAPE

2.00

4.00

(2 LOCATIONS)

4.00

(2 LOCATIONS)

4.00

(2 LOCATIONS)

(2 LOCATIONS)

7.00

TYPICAL ARRANGEMENT FOR ALL

ANGLED AIR OUTLETS EXCEPT AS NOTED

(4 LOCATIONS)

F-F

E-E

N29354
 APPENDIX B: BAC 5412 METHOD VII - BONDING DUCT JOINTS

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APPENDIX B: BAC 5412 METHOD VII - BONDING DUCT JOINTS

1. Coat the three inch wide fiberglass tape, Style 116 on one side with BAC 5010, Type 98 adhesive. If the 

adhesive coated tape is not applied within approximately 30 minutes, a tack free skin may form, interfering 

with adhesion. Use extreme caution during application to assure that no adhesive is applied outside the 

bond area if subsequent finishing is required.

2. Wrap one layer of coated tape (with adhesive down) over the joint with a minimum of one inch on each 

duct. Overlap the tape ends 1 to 2 inches at the tape joint except, that for ducts with nozzle openings, no 

overlap of the tape ends is required. Pull out wrinkles in the fiberglass tape and smooth out any voids or 

air pockets between the fiberglass tape and the duct. Apply positive pressure to ensure contact of the 

adhesive to the duct. A bondline thickness of 0.04 to 0.08 inch is required. This is approximately 1.5 

ounces of adhesive per foot of 3 inch tape.

3. Allow the adhesive to cure under contact pressure for a minimum of 24 hours at 65 to 100 degrees 

Fahrenheit. A minimum of 20 percent relative humidity is required for adhesive cure. If the relative humidity 

falls below 20 percent, extend the cure time sufficiently to assure that there is a total of 24 hours of cure 

with the relative humidity at or above 20 percent.

Material Required

QTY Part Number {Specification} Name

6 feet Style 116 Per BMS 9-3R, Type C, Class

7, slit and sealed, 3 inches nominal

width

Fiberglass Tape (a)

4 ounces BAC5010, Type 98 (GE RTV 133) Adhesive (b)

Vendor Contact Information

(a) See the Qualified Products List at the end of the Boeing Material Specification

(BMS) for supplier data.

(b) General Electric Co. Silicon Products Business Department

Hudson River Road

Waterford, New York, 12188, USA
 APPENDIX C: BAC 5412 METHOD VIII - TAPED TELESCOPING JOINTS

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APPENDIX C: BAC 5412 METHOD VIII - TAPED TELESCOPING JOINTS

1. Sharp Edges of duct should be smoothed with a file.

2. Telescope the two ducts so that there is at least 1/2 inch overlap of the duct.

3. Clean the area to be taped using cleaning solvents for kevlar/epoxy: Refer to BSOPM 20-30-03, 20-60-01 

or (BAC 5750).

4. Apply two laps of 2 inch wide Venture Tape No. 3959 to the center of the joint, pulling tight and smoothing 

while applying.

Material Required

QTY Part Number {Specification} Name

6 feet Venture Tape No. 3959 Vinyl Plastic Tape (a)

Vendor Contact Information

(a) Venture Tape Corp

30-T Commerce Road

Rockland, Maine 02370, USA

DIAGRAM OF TAPED TELESCOPING JOINTS

TAPE

N26047