# Boeing Alert Service Bulletin 747-21A2421: Revision 2 - Rights: © The Boeing Company. Filed by the FAA in regulations.gov docket FAA-2010-0275; AD 2010-14-01 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. - Document: [Boeing Alert Service Bulletin 747-21A2421](https://openairdocs.org/service-documents/boeing/747-21a2421.md) - Title as filed: Boeing Service Bulletin - Pages: 809 - PDF: https://openairdocs.org/files/sha256/77/fe/77fe16136c3662c839ae6d2be8c2b3754c475f1f93946222a62cbbfbab8d1bbf - Page: https://openairdocs.org/service-documents/boeing/747-21a2421/file/77fe16136c36 ## Text Each page's text from the PDF; open the PDF at a page with #page=N. ### Page 1 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 1 of 809 Commercial Airplane Group 747 Service Bulletin Number: 747-21A2421 Date: August 14, 2003 Revision 2: December 19, 2006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BMS 8-39 Foam, Replacement BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET Copyright © 2003 The Boeing Company Unpublished Work - All Rights Reserved Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable subject matter.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. ### Page 2 BLANK PAGE August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 2 of 809 BOEING SERVICE BULLETIN 747-21A2421 BLANK PAGE ### Page 3 Table of Contents August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 3 of 809 BOEING SERVICE BULLETIN 747-21A2421 Table of Contents Revision Transmittal Sheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 1. PLANNING INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 A. Effectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 1. Airplanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 B. Concurrent Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 C. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 H. Weight and Balance Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 1. Existing Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 2. Data supplied with this Service Bulletin: . . . . . . . . . . . . . . . . . . . . . . . . . 28 3. Installation Drawings Used in the Preparation of this Service Bulletin: . . . . . . . . . . 29 4. Process Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . 30 2. MATERIAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 A. Material - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 C. Parts Necessary For Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 1. Kits/Parts: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 2. Parts and Materials Supplied by the Operator: . . . . . . . . . . . . . . . . . . . . . . 32 3. Parts Modified and Reidentified: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 4. Parts Removed and Not Replaced: . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 D. Parts Necessary to Change Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 F. Special Tooling Necessary to do this Service Bulletin . . . . . . . . . . . . . . . . . . . . . 55 3. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 B. WORK INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 FIGURE 1: AIR CONDITIONING, FLIGHT DECK, STA 323 - STA 500 . . . . . . . . . . . . . . . . . 496 FIGURE 2: AIR CONDITIONING - FLIGHT DECK, STA 323 - STA 520 . . . . . . . . . . . . . . . . 498 FIGURE 3: AIR CONDITIONING - FLIGHT DECK, STA 323 - STA 520 . . . . . . . . . . . . . . . . 500 FIGURE 4: AIR CONDITIONING - FLIGHT DECK, STA 323 - STA 520 . . . . . . . . . . . . . . . . 502 FIGURE 5: FLIGHT DECK, AIR CONDITIONING, SECTION 42 . . . . . . . . . . . . . . . . . . . . 504 FIGURE 6: FLIGHT DECK, AIR CONDITIONING, SECTION 42 . . . . . . . . . . . . . . . . . . . . 507 FIGURE 7: FLIGHT DECK, AIR CONDITIONING, SECTION 42 . . . . . . . . . . . . . . . . . . . . 511 FIGURE 8: FLIGHT DECK, AIR CONDITIONING, SECTION 42 . . . . . . . . . . . . . . . . . . . . 513 FIGURE 9: FLIGHT DECK, AIR CONDITIONING, SECTION 42 . . . . . . . . . . . . . . . . . . . . 515 FIGURE 10: FLIGHT DECK, AIR CONDITIONING, SECTION 42 . . . . . . . . . . . . . . . . . . . 517 ### Page 4 Table of Contents August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 4 of 809 BOEING SERVICE BULLETIN 747-21A2421 FIGURE 11: FLIGHT DECK, AIR CONDITIONING, SECTION 42 . . . . . . . . . . . . . . . . . . . 519 FIGURE 12: AIR CONDITIONING - FLIGHT DECK, STA 260 - STA 340 . . . . . . . . . . . . . . . 521 FIGURE 13: AIR CONDITIONING - FLIGHT DECK, STA 260 - STA 340 . . . . . . . . . . . . . . . 523 FIGURE 14: DUCT INSTALLATION - CONDITIONED AIR, STATEROOM . . . . . . . . . . . . . . 525 FIGURE 15: DUCT INSTALLATION - CONDITIONED AIR, STATEROOM . . . . . . . . . . . . . . 529 FIGURE 16: DUCT INSTALLATION - CONDITIONED AIR, STA 206 TO STA 464 . . . . . . . . . . 532 FIGURE 17: DUCT INSTALLATION - CONDITIONED AIR, STA 206 TO STA 464 . . . . . . . . . . 535 FIGURE 18: DUCT INSTALLATION - CONDITIONED AIR, STA 516 TO STA 737 . . . . . . . . . . 538 FIGURE 19: DUCT INSTALLATION - ZONE 11, STA 475.75 TO STA 516.0 . . . . . . . . . . . . . 541 FIGURE 20: DUCT INSTALLATION - ZONE 11, STA 475.75 TO STA 516.0 . . . . . . . . . . . . . 543 FIGURE 21: DUCT INSTALLATION - AIR DISTRIBUTION SYSTEM, ZONE 2 . . . . . . . . . . . . 545 FIGURE 22: DUCT INSTALLATION - AIR DISTRIBUTION SYSTEM, ZONE 2 . . . . . . . . . . . . 547 FIGURE 23: DUCT INSTALLATION - AIR DISTRIBUTION SYSTEM, ZONE 2 . . . . . . . . . . . . 550 FIGURE 24: DUCT INSTALLATION - AIR DISTRIBUTION SYSTEM, ZONE 2 . . . . . . . . . . . . 552 FIGURE 25: DUCT INSTALLATION - AIR DISTRIBUTION SYSTEM, ZONE 2 . . . . . . . . . . . . 554 FIGURE 26: DUCT INSTALLATION - ZONE 3, AIR DISTRIBUTION SYSTEM . . . . . . . . . . . . 556 FIGURE 27: DUCT INSTALLATION - ZONE 3, AIR DISTRIBUTION SYSTEM . . . . . . . . . . . . 558 FIGURE 28: DUCT INSTALLATION - ZONE 4, AIR DISTRIBUTION SYSTEM . . . . . . . . . . . . 560 FIGURE 29: DUCT INSTALLATION - ZONE 4, AIR DISTRIBUTION SYSTEM . . . . . . . . . . . . 562 FIGURE 30: DUCT INSTALLATION - ZONE 4, AIR DISTRIBUTION SYSTEM . . . . . . . . . . . . 564 FIGURE 31: DUCT INSTALLATION - ZONE 4, AIR DISTRIBUTION SYSTEM . . . . . . . . . . . . 566 FIGURE 32: LEFT SIDE RISER INSTALLATION - AIR DISTRIBUTION SYSTEM . . . . . . . . . . 568 FIGURE 33: RIGHT SIDE RISER INSTALLATION - AIR DISTRIBUTION SYSTEM . . . . . . . . . 571 FIGURE 34: LEFT SIDE RISER INSTALLATION - AIR DISTRIBUTION SYSTEM . . . . . . . . . . 575 FIGURE 35: RIGHT SIDE RISER INSTALLATION - AIR DISTRIBUTION SYSTEM . . . . . . . . . 577 FIGURE 36: LEFT SIDE RISER INSTALLATION - AIR DISTRIBUTION SYSTEM . . . . . . . . . . 579 FIGURE 37: RIGHT SIDE RISER INSTALLATION - AIR DISTRIBUTION SYSTEM . . . . . . . . . 581 FIGURE 38: LEFT SIDE RISER INSTALLATION - AIR DISTRIBUTION SYSTEM . . . . . . . . . . 583 FIGURE 39: RIGHT SIDE RISER INSTALLATION - AIR DISTRIBUTION SYSTEM . . . . . . . . . 585 FIGURE 40: FAN INSTALLATION - INDIVIDUAL AIR SYSTEM. . . . . . . . . . . . . . . . . . . . 587 FIGURE 41: FAN INSTALLATION - INDIVIDUAL AIR SYSTEM. . . . . . . . . . . . . . . . . . . . 589 FIGURE 42: ANEMOSTAT INSTALLATION - STA 165, AIR DISTRIBUTION SYSTEM . . . . . . . 591 FIGURE 43: HUMIDIFIER DUCT INSTALLATION - CREW CABIN, ZONE 1 . . . . . . . . . . . . . 593 FIGURE 44: HEAT EXCHANGER INSTALLATION - AIR COND SYSTEM, LOWER LOBE GALLEY 595 FIGURE 45: HEAT EXCHANGER INSTALLATION - AIR COND SYSTEM, LOWER LOBE GALLEY 597 FIGURE 46: HEAT EXCHANGER INSTALLATION - AIR COND SYSTEM, LOWER LOBE GALLEY 599 FIGURE 47: INSULATION INSTL - CONDITIONED AIR PLENUM . . . . . . . . . . . . . . . . . . 601 FIGURE 48: INSULATION INSTL - CONDITIONED AIR MIX BAY, STA 1000 - STA 1265 . . . . . . 603 FIGURE 49: RECIRCULATION FAN INSTALLATION - FLIGHT DECK . . . . . . . . . . . . . . . . 605 FIGURE 50: RECIRCULATION FAN INSTALLATION - FLIGHT DECK . . . . . . . . . . . . . . . . 607 FIGURE 51: RECIRCULATION FAN INSTALLATION - FLIGHT DECK . . . . . . . . . . . . . . . . 609 FIGURE 52: RECIRCULATION FAN INSTALLATION - FLIGHT DECK . . . . . . . . . . . . . . . . 611 FIGURE 53: RECIRCULATION FAN INSTALLATION - FLIGHT DECK . . . . . . . . . . . . . . . . 613 FIGURE 54: DUCT INSTALLATION - CONDITIONED AIR MANIFOLD, STA 1000 - STA 1265 . . . 615 FIGURE 55: DUCT INSTALLATION - GASPER AIR SYSTEM, MAIN DECK . . . . . . . . . . . . . 617 FIGURE 56: DUCT INSTALLATION - GASPER AIR SYSTEM, MAIN DECK . . . . . . . . . . . . . 621 ### Page 5 Table of Contents August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 5 of 809 BOEING SERVICE BULLETIN 747-21A2421 FIGURE 57: DUCT INSTALLATION - GASPER AIR SYSTEM, MAIN DECK . . . . . . . . . . . . . . 624 FIGURE 58: DUCT INSTALLATION - GASPER AIR SYSTEM, MAIN DECK . . . . . . . . . . . . . . 626 FIGURE 59: DUCT INSTALLATION - GASPER AIR SYSTEM, MAIN DECK . . . . . . . . . . . . . . 628 FIGURE 60: DUCT INSTALLATION - GASPER AIR SYSTEM, MAIN DECK . . . . . . . . . . . . . . 631 FIGURE 61: DUCT INSTALLATION - ZONE 3 FEEDER . . . . . . . . . . . . . . . . . . . . . . . . 634 FIGURE 62: THIS FIGURE IS NOT USED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 3 6 FIGURE 63: DUCT INSTALLATION - AIR CONDITIONING SYS, CREW REST COMPARTMENT . . 637 FIGURE 64: DUCT INSTALLATION - AIR CONDITIONING SYS, CREW REST COMPARTMENT . . 639 FIGURE 65: THIS FIGURE IS NOT USED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 4 1 FIGURE 66: DUCT INSTALLATION - AIR CONDITIONING SYS, CREW REST COMPARTMENT . . 642 FIGURE 67: DUCT INSTALLATION - P8 PANEL COOLING, FLIGHT DECK . . . . . . . . . . . . . 644 FIGURE 68: DUCT INSTALLATION - ZONE 2, STA 456 - STA 516 . . . . . . . . . . . . . . . . . . 646 FIGURE 69: DUCT INSTALLATION - AIR DISTRIBUTION SYSTEM, ZONE 2. . . . . . . . . . . . . 648 FIGURE 70: DUCT INSTALLATION - AIR DISTRIBUTION SYSTEM, ZONE 2. . . . . . . . . . . . . 650 FIGURE 71: DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, ZONE D AND E . . . . . . . . . . 652 FIGURE 72: DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, ZONE D AND E . . . . . . . . . . 654 FIGURE 73: DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, ZONE D AND E . . . . . . . . . . 656 FIGURE 74: DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, ZONE D AND E . . . . . . . . . . 658 FIGURE 75: DUCT INSTALLATION - AIR DISTRIBUTION, ZONE 4, FEEDER . . . . . . . . . . . . 662 FIGURE 76: DUCT INSTALLATION - AIR DISTRIBUTION, ZONE 2 . . . . . . . . . . . . . . . . . . 664 FIGURE 77: DUCT INSTALLATION - AIR DISTRIBUTION, ZONE 2 . . . . . . . . . . . . . . . . . . 666 FIGURE 78: DUCT INSTALLATION - AIR DISTRIBUTION SYSTEM, ZONE 3 . . . . . . . . . . . . 668 FIGURE 79: DUCT INSTALLATION - AIR DISTRIBUTION SYSTEM, ZONE 3 . . . . . . . . . . . . 670 FIGURE 80: DUCT INSTALLATION - AIR DISTRIBUTION, UPPER DECK COMPARTMENT . . . . . 672 FIGURE 81: DUCT INSTALLATION - AIR DISTRIBUTION, UPPER DECK COMPARTMENT . . . . . 674 FIGURE 82: DUCT INSTALLATION - AIR DISTRIBUTION, UPPER DECK COMPARTMENT . . . . . 676 FIGURE 83: DUCT INSTALLATION - AIR DISTRIBUTION, UPPER DECK COMPARTMENT . . . . . 679 FIGURE 84: DUCT INSTALLATION - AIR DISTRIBUTION, UPPER DECK COMPARTMENT . . . . . 681 FIGURE 85: DUCT INSTALLATION - AIR DISTRIBUTION, UPPER DECK COMPARTMENT . . . . . 683 FIGURE 86: DUCT INSTALLATION - AIR DISTRIBUTION, UPPER DECK COMPARTMENT . . . . . 685 FIGURE 87: DUCT INSTALLATION - AIR DISTRIBUTION, UPPER DECK COMPARTMENT . . . . . 687 FIGURE 88: DUCT INSTALLATION - AIR DISTRIBUTION, UPPER DECK COMPARTMENT . . . . . 689 FIGURE 89: DUCT INSTALLATION - AIR DISTRIBUTION, UPPER DECK COMPARTMENT . . . . . 691 FIGURE 90: DUCT INSTALLATION - AIR DISTRIBUTION, UPPER DECK COMPARTMENT . . . . . 695 FIGURE 91: DUCT INSTALLATION - AIR DISTRIBUTION, UPPER DECK COMPARTMENT . . . . . 699 FIGURE 92: DUCT INSTALLATION - AIR DISTRIBUTION, UPPER DECK COMPARTMENT . . . . . 701 FIGURE 93: DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, LAVATORIES . . . . . . . . . . . 703 FIGURE 94: DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, LAVATORIES . . . . . . . . . . . 705 FIGURE 95: DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, LAVATORIES . . . . . . . . . . . 707 FIGURE 96: DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, LAVATORIES . . . . . . . . . . . 709 FIGURE 97: DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, LAVATORIES . . . . . . . . . . . 711 FIGURE 98: DUCT INSTALLATION - AIR DISTRIBUTION SYS, LOWER AFT CARGO COMPARTMENT 713 FIGURE 99: DUCT INSTALLATION - AIR DISTRIBUTION SYS, LOWER AFT CARGO COMPARTMENT 716 FIGURE 100: DUCT INSTALLATION - CONDITIONED AIR, MAIN DECK CREW REST . . . . . . . 720 ### Page 6 Table of Contents August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 6 of 809 BOEING SERVICE BULLETIN 747-21A2421 FIGURE 101: DUCT INSTALLATION - CONDITIONED AIR, RIGHT HAND CREW REST . . . . . . 722 FIGURE 102: DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, PASSENGER CABIN . . . . . . 724 FIGURE 103: DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, PASSENGER CABIN . . . . . . 726 FIGURE 104: DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, PASSENGER CABIN . . . . . . 729 FIGURE 105: DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, PASSENGER CABIN . . . . . . 731 FIGURE 106: DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, PASSENGER CABIN . . . . . . 733 FIGURE 107: DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, PASSENGER CABIN . . . . . . 735 FIGURE 108: DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, PASSENGER CABIN . . . . . . 737 FIGURE 109: DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, PASSENGER CABIN . . . . . . 739 FIGURE 110: DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, PASSENGER CABIN . . . . . . 742 FIGURE 111: DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, PASSENGER CABIN . . . . . . 745 FIGURE 112: DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, UPPER DECK LOUNGE/ FLIGHT DECK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 747 FIGURE 113: DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, PASSENGER CABIN . . . . . . 752 FIGURE 114: DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, MAIN CABIN . . . . . . . . . . 756 FIGURE 115: HEATING INSTALLATION - PASSENGER CABIN DOOR . . . . . . . . . . . . . . . 758 FIGURE 116: AIR DISTRIBUTION INSTALLATION - MAIN DECK, CREW REST . . . . . . . . . . 761 FIGURE 117: DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, LAVATORIES . . . . . . . . . . 763 FIGURE 118: DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, LAVATORIES . . . . . . . . . . 767 FIGURE 119: DUCT INSTALLATION - AIR DISTRIBUTION SYSTEM, ZONE 2 . . . . . . . . . . . 770 FIGURE 120: DUCT INSTALLATION - AIR DISTRIBUTION SYSTEM, ZONE 2 . . . . . . . . . . . 772 FIGURE 121: DUCT INSTALLATION - AIR DISTRIBUTION SYSTEM, ZONE 2 . . . . . . . . . . . 774 FIGURE 122: DUCT INSTALLATION - AIR DISTRIBUTION SYS, PASSENGER CABIN . . . . . . . 776 FIGURE 123: DUCT INSTALLATION - AIR DISTRIBUTION SYS, PASSENGER CABIN (SHEET 3). 779 FIGURE 124: DUCT INSTALLATION - AIR DISTRIBUTION SYSTEM, PASSENGER CABIN . . . . 783 FIGURE 125: DUCT INSTALLATION - AIR DISTRIBUTION SYSTEM, PASSENGER CABIN . . . . 785 FIGURE 126: DUCT INSTALLATION - AIR DISTRIBUTION SYSTEM, PASSENGER CABIN . . . . 787 FIGURE 127: DUCT INSTALLATION - AIR DISTRIBUTION SYSTEM, PASSENGER CABIN . . . . 789 FIGURE 128: DUCT INSTALLATION - AIR DISTRIBUTION SYSTEM, PASSENGER CABIN . . . . 791 FIGURE 129: DUCT INSTALLATION - AIR DISTRIBUTION SYSTEM, PASSENGER CABIN . . . . 793 FIGURE 130: DUCT INSTALLATION - AIR CONDITIONING SYS CREW REST COMPARTMENT . 795 FIGURE 131: DUCT INSTALLATION - AIR DISTRIBUTION SYSTEM, PASSENGER CABIN . . . . 797 FIGURE 132: DUCT INSTALLATION - FLIGHT DECK, CONDITIONED AIR . . . . . . . . . . . . . 799 APPENDIX A: PROCESS DATA - APPLICATION OF BMS 8-300 BY TAPING WITH BMS 5-157 TAPE. 800 APPENDIX B: TIE STRAP SELECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 805 APPENDIX C: BAC 5412 METHOD VII - BONDING DUCT JOINTS . . . . . . . . . . . . . . . . . 806 APPENDIX D: BAC5412 METHOD VIII - TAPED TELESCOPING JOINTS . . . . . . . . . . . . . . 807 APPENDIX E: AIR DISTRIBUTION SYSTEM PRESSURE CHECK - CHART 1. . . . . . . . . . . . 808 APPENDIX F: AIR DISTRIBUTION SYSTEM PRESSURE CHECK - CHART 2. . . . . . . . . . . . 809 ### Page 7 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 7 of 809 Commercial Airplane Group 747 Service Bulletin Number: 747-21A2421 Revision Transmittal Sheet Date: August 14, 2003 Revision 2: December 19, 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 original issue 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 the service bulletin include: — A Boeing recommended compliance time is given. — 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, 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. 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. ### Page 8 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 8 of 809 BOEING SERVICE BULLETIN 747-21A2421 REVISION HISTORY Original Issue: August 14, 2003 Revision 1 December 21, 2004 Revision 2 December 19, 2006 ### Page 9 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 9 of 809 Commercial Airplane Group 747 Service Bulletin Number: 747-21A2421 Summary Date: August 14, 2003 Revision 2: December 19, 2006 ATA System: 2122 SUBJECT: AIR CONDITIONING - Distribution - Duct Insulation BMS 8-39 Foam, Replacement CONCURRENT REQUIREMENTS None. BACKGROUND Some 747 airplanes were assembled with air distribution ducts wrapped with BMS 8-39, polyurethane foam insulation. The fire retardant properties of this polyurethane foam insulation can degrade with age and become a possible fire hazard. BMS 8-39 polyurethane foam insulation meets all flammability requirements, including Federal Aviation Regulation (FAR) 25.853, upon delivery. It has been found that there can be deterioration of these fire retardant properties with age. This, along with dust, dirt and other carbon particulate contamination of the BMS 8-39 insulation on these ducts, adds an available fuel source to the insulation. This can cause the duct assemblies to no longer meet FAR 25.853. This service bulletin provides rework instructions for the affected duct assemblies and environmental control system (ECS) related parts. Replacement of the old insulation material on these ECS parts and duct assemblies with a new insulation material that meets FAR 25.853 requirements will improve fire safety. The existing BMS 8-39 polyurethane insulation is removed and new BMS 8-300 polyimide foam insulation is installed. There have been two reports of burned BMS 8-39 polyurethane foam insulation on the 767 airplane. Boeing Service Related Problem (SRP) 747-SRP-21-0130 is related to this service bulletin. ACTION (PRR 85901-18RS) Rework the affected duct and ECS related assemblies in the areas as described by the Figure titles. The existing insulation will be removed and replaced with a new, BMS 8-300 insulation. Perform the functional tests as required. EFFECTIVITY See paragraph 1.A. Effectivity. ### Page 10 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 10 of 809 BOEING SERVICE BULLETIN 747-21A2421 COMPLIANCE Boeing recommends this change be accomplished during the next heavy maintenance visit, not to exceed 30,000 flight-hours from the date on this service bulletin. 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 Boeing warranty remedies are not available for the configuration changes given in this service bulletin. MANPOWER Man-hours required to accomplish this change are averaged at 7.25 hours for each duct assembly. Functional test require a crew of two 7.5 man-hours, with an elapsed time of 3.75 hours. MATERIAL INFORMATION Operator Supplied Materials. Refer to Paragraph 2.A., Material - Price and Availability. ### Page 11 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 11 of 809 BOEING SERVICE BULLETIN 747-21A2421 REWORK AS REQUIRED, ECS DUCT ASSEMBLIES AND COMPONENTS BY REMOVING EXISTING BMS 8-39 INSULATION AND REPLACING WITH BMS 8-300 INSULATION. (SEE FIGURES FOR SYSTEM LOCATIONS) N59155 ### Page 12 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 12 of 809 BOEING SERVICE BULLETIN 747-21A2421 BLANK PAGE ### Page 13 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 13 of 809 Commercial Airplane Group 747 Service Bulletin Number: 747-21A2421 Date: August 14, 2003 Revision 2: December 19, 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. Refer to PRR 85901-18RS for data about this change. Airplane models: 747-100 747-100B 747-100B SUD 747-200B 747-200C 747-200F 747-300 747-400 747SP 747SR IDENTIFICATION BY CUSTOMER, CUSTOMER CODE, GROUP AND VARIABLE NUMBER AAR A/C ENG. SALES & LEASING (AFD) 1 RB681–RB682 AERO CONTROLS (AEO) 1 RA722–RA723 AEROLINEAS ARGENTINAS (ARG) 1 RD122–RD127 AFRICA UNITED HOLDING CO. (UHD) 1 RB010 GROUP CONFIGURATION DESCRIPTION 1 - 747 airplanes assembled with air distribution ducts wrapped with BMS 8-39 insulation. ### Page 14 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 14 of 809 BOEING SERVICE BULLETIN 747-21A2421 AFX (AXL) 1 RD201 RR221 AGES AIRCRAFT SALES & LEASING (AGJ) 1R B 0 0 4 AIR ATLANTA ICELANDIC (AID) 1 RB411–RB413 RB421 RD141 RD414 RD456 RD647–RD648 RD755 RD771 RD774 RR204 RR206 RR332 RS211 RS222 RS233 RS235 RS237 RS332–RS333 AIR CANADA (ACN) 1 RA749–RA750 RD531 AIR CHINA (BEJ) 1 RD781–RD783 RR451 RT031–RT033 AIR FRANCE (AFA) 1 RD657–RD659 RD721–RD722 RR306–RR309 RS751–RS752 AIR GULF FALCON (GFG) 1R A 5 3 5 R A 5 3 7 AIR INDIA (AIN) 1 RA729 RA731 RS781–RS782 AIR PLUS COMET (PLD) 1 RD053 AIR PULLMANTUR (PUL) 1 RD655 RD791 RS331 AIR UNIVERSAL (UVL) 1 RD231–RD232 RD291–RD292 RD775 ALBARAKA (AAB) 1R B 1 0 2 ALL NIPPON AIRWAYS (ANA) 1 RB691–RB693 RB695 RT751–RT752 AMIRI FLIGHT (ABD) 1 RH102 ARKIA ISRAELI AIRLINES (ARK) 1R A 2 5 3 ATLAS AIR (TLS) 1 RB684 RD361–RD366 RD411 RD641–RD642 RD646 RD691–RD692 RD752–RD754 RJ333 RR301 RR303 RS722 ### Page 15 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 15 of 809 BOEING SERVICE BULLETIN 747-21A2421 AVIATION EXPOSURE MANAGEMENT (EXU) 1 RD131–RD132 RD143 BAHRAIN ROYAL FLIGHT (BHR) 1 RG009 BANC OF AMERICA LEASING (SBC) 1 RA106 RD001–RD002 BOEING (TBC) 1 RR222–RR223 BOEING AIRCRAFT HOLDING CO. (BHC) 1 RD181 RD451–RD454 BOEING CAPITAL CORPORATION (ZMF) 1 RB687 RD072 RJ132 RR201 BOEING WICHITA MOD CENTER (WMC) 1 RD455 C.A.L. CARGO AIR LINES (CRG) 1 RJ331–RJ332 C.I.T. LEASING CORPORATION (TCI) 1 RD047 CARGO 360, INC. (CGN) 1 RR024–RR025 RS786 CATHAY PACIFIC AIRWAYS (CAT) 1 RD358 RD581–RD583 RR441–RR442 RR531 CORSAIR (COR) 1 RS239–RS240 RT613–RT614 RT616 RT618 DRAGONAIR (DRG) 1 RR522 RS741 RS743 RS771 DUBAI AIR WING (DAW) 1 RD622 RG191 EAGLE AVIATION (EAE) 1 RT602 RT606 EGYPTAIR (EGP) 1 RS731–RS732 EL AL ISRAEL AIRLINES (ELA) 1 RD442 RJ152 RR225–RR226 EUROPEAN AVIATION AIR CHARTER (EUL) 1 RD135–RD138 RD311 ### Page 16 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 16 of 809 BOEING SERVICE BULLETIN 747-21A2421 EVERGREEN INTERNATIONAL A/L (EVR) 1 RA028 RA631 RA633 RB604 RB607 RD004 RD041–RD043 RD772–RD773 RJ131 RJ133 EXPORT RESTRICTED AIRPLANES (YWV) 1 RA101–RA103 RA112 RA161–RA163 RD513 RG171 RR001–RR004 FINOVA (GRB) 1R A 6 5 1 R S 7 6 1 FIRST CHICAGO CORP. (FCC) 1 RD260 GA TELESIS (GTG) 1 RG163 GE (GEC) 1R A 0 1 6 GE CAPITAL CORPORATION (GEF) 1 RA007 RA013 RA027 GLOBAL AIR LEASING (GAO) 1 RG164 GLOBAL PEACE INITIATIVE (GPI) 1 RG174 GRACE CATHEDRAL INC. (GCI) 1 RG193 GUGGENHEIM AVIATION PARTNERS (GPR) 1 RB697 RT021–RT022 IBERIA AIRLINES (IBE) 1 RD431–RD435 INTERNATIONAL AIR LEASES (IAL) 1R B 0 0 6 IRAN AIR (IRN) 1 RB711 RD681–RD682 RG101–RG104 IRAQI AIRWAYS (IRQ) 1 RG095 RG172 RJ301–RJ303 JAL INTERNATIONAL (JAL) 1 RA546 RA548 RD055 RD222–RD227 RR264–RR267 RR361–RR362 RS001–RS002 RS251–RS259 RS265–RS268 RT641–RT647 ### Page 17 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 17 of 809 BOEING SERVICE BULLETIN 747-21A2421 JAPAN ASIA AIRWAYS (JAA) 1 RS263 JET AERO HOLDINGS (JHD) 1 RG122 JUMBO JET LEASING (JJL) 1 RA526 RA532–RA534 RA539 KABO AIR (KAB) 1 RA305 RA316 RA560 RB008 RD121 KALITTA AIR (KAC) 1 RA401–RA402 RA524 RA545 RA547 RA635 RA913 RB605 RD054 RD082–RD083 RD221 RD571 RD623 RR261–RR262 RR501 RR521 KLM - ROYAL DUTCH AIRLINES (KLM) 1 RD382 RD607 KOREAN AIR (KAL) 1 RT061 KUWAIT AIRWAYS (KUW) 1 RD202 RD204 L-3 COMMUNICATIONS (LCS) 1 RD352 LOGISTIC AIR, INC. (LGA) 1 RA015 RA217 RB722–RB723 MARTINAIR HOLLAND (MTH) 1 RD601 RJ321–RJ322 RR310 MK AIRLINES (MKA) 1 RD441 RD561 RR022–RR023 RR224 RR336 RR421 NASA (NAS) 1 RA908 RB601 NEA HOLDINGS, INC. (NEA) 1 RB001 RD045–RD046 NIPPON CARGO AIRLINES (NCA) 1 RB696 RD233–RD235 RD461 RR551 RR553–RR556 ### Page 18 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 18 of 809 BOEING SERVICE BULLETIN 747-21A2421 NORTHWEST AIRLINES (NWA) 1 RA370–RA373 RD056–RD057 RD241–RD243 RD251–RD259 RD261–RD262 RD301–RD302 RR005 RR341–RR345 RR431–RR432 RR503 RR566 RS701–RS702 OCEAN AIRLINES (OCE) 1 RR202–RR203 OMAN ROYAL FLIGHT (RFO) 1 RG161 OMEGA AIR HOLDINGS (OMC) 1 RB694 RD142 RD144 RD412 RS721 ORIENT THAI AIRLINES (OTH) 1 RA528 RA540 RA543–RA544 RD516 RS292 RS712 PAKISTAN INT'L AIRLINES (PIA) 1 RD104 RD701–RD702 RS301–RS306 PHUKET AIRLINES (PHK) 1 RD381 RD421–RD424 RD605 RS238 RS241 RS711 POLAR AIR CARGO (PAO) 1 RA910 RR504 PRATT & WHITNEY ENGINE SERVICE (PWE) 1 RG213 QANTAS (QAN) 1 RS271–RS276 ROYAL AIR MAROC (RAM) 1 RD671 S583 (583) 1 RD166–RD167 SATAIR (SAI) 1 RD383 RD606 SAUDI ARABIAN AIRLINES (SVA) 1 RB741–RB746 RB748 RH121 RR526 RS311–RS320 SAUDI ROYAL FLIGHT (SRF) 1 RH101 RH122 RS699 SKY EXPRESS S.A. (SXS) 1 RD592 ### Page 19 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 19 of 809 BOEING SERVICE BULLETIN 747-21A2421 SOUTH AFRICAN AIRWAYS (SAA) 1 RG123 RG125 RS212 RS232 RS236 SOUTHERN AIR (SOF) 1 RD182 RD272 RD602 RD604 RD643 RD792 RR302 RR304–RR305 SUO1 (UO1) 1 RB013–RB016 SURINAM AIRWAYS (SUR) 1 RS713 SYRIANAIR (SYR) 1 RG141–RG142 TAAG (ANGOLA AIRLINES) (ANG) 1 RS703 RS742 TESIS AVIATION ENTERPRISE (TEV) 1 RA784 THAI AIRWAYS INTERNATIONAL (TII) 1 RS341–RS342 RT691–RT692 TRADEWINDS AIRLINES (TWN) 1 RA726 RD052 RD426 TRANSAERO AIRLINES (TRX) 1 RD356 RD471–RD475 TRANSATLANTIC INTL AIRLINES (TIB) 1 RG173 UNITED AIRLINES (UAL) 1 RA903 RA906–RA907 RB011 RT601 RT603–RT605 RT607–RT612 RT615 RT617 UPS (UPS) 1 RA026 RA029 RA033 RA902 RA912 RA915–RA916 RD051 RD058–RD059 RD593 USRA (USP) 1 RG091 VIRGIN ATLANTIC AIRWAYS (VAA) 1 RD357 VOLGA-DNEPR AIRLINES (VDA) 1 RD751 RR552 RR561 RS762 ### Page 20 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 20 of 809 BOEING SERVICE BULLETIN 747-21A2421 WHIRLPOOL FINANCIAL CORP. (ZZW) 1R B 0 0 5 WINGS WORLD WIDE (WWW) 1 RG221–RG222 WORLDWIDE AIRCRAFT HOLDING CO. (WAH) 1 RG008 YEMENIA (YEM) 1 RG162 IDENTIFICATION BY VARIABLE NUMBER Variable Group RA002–RA007 1 RA013 1 RA015–RA016 1 RA023 1 RA026–RA030 1 RA033 1 RA101–RA103 1 RA106 1 RA112–RA113 1 RA161–RA163 1 RA217 1 RA253 1 RA257 1 RA303 1 RA305–RA306 1 RA313 1 RA315–RA317 1 RA370–RA373 1 RA401–RA405 1 RA501–RA502 1 RA522 1 RA524 1 RA526–RA528 1 RA532–RA535 1 RA537 1 RA539–RA548 1 RA560–RA561 1 RA585 1 ### Page 21 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 21 of 809 BOEING SERVICE BULLETIN 747-21A2421 RA631 1 RA633–RA635 1 RA651 1 RA675 1 RA722–RA723 1 RA726 1 RA728–RA731 1 RA742 1 RA749–RA750 1 RA784 1 RA901–RA904 1 RA906–RA908 1 RA910–RA916 1 RB001 1 RB004–RB011 1 RB013–RB016 1 RB071–RB075 1 RB102 1 RB411–RB413 1 RB421 1 RB601 1 RB604–RB605 1 RB607 1 RB681–RB685 1 RB687–RB697 1 RB711 1 RB721–RB723 1 RB741–RB746 1 RB748 1 RD001–RD004 1 RD022 1 RD041–RD059 1 RD071–RD072 1 RD081–RD083 1 RD091 1 RD101–RD104 1 RD121–RD127 1 RD131–RD144 1 RD166–RD167 1 Variable Group ### Page 22 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 22 of 809 BOEING SERVICE BULLETIN 747-21A2421 RD171–RD172 1 RD181–RD182 1 RD201–RD202 1 RD204 1 RD221–RD227 1 RD231–RD235 1 RD241–RD243 1 RD251–RD262 1 RD271–RD272 1 RD291–RD292 1 RD301–RD302 1 RD311 1 RD352–RD358 1 RD361–RD366 1 RD381–RD383 1 RD411–RD414 1 RD421–RD426 1 RD431–RD435 1 RD441–RD442 1 RD451–RD456 1 RD461 1 RD471–RD475 1 RD513 1 RD515–RD519 1 RD531–RD533 1 RD551 1 RD561 1 RD571 1 RD581–RD583 1 RD592–RD593 1 RD601–RD607 1 RD622–RD623 1 RD641–RD643 1 RD645–RD648 1 RD651–RD655 1 RD657–RD659 1 RD661 1 RD671 1 RD681–RD682 1 Variable Group ### Page 23 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 23 of 809 BOEING SERVICE BULLETIN 747-21A2421 RD691–RD692 1 RD701–RD702 1 RD721–RD722 1 RD741 1 RD751–RD755 1 RD771–RD775 1 RD781–RD783 1 RD791–RD792 1 RE001 1 RG008–RG009 1 RG091 1 RG095 1 RG101–RG104 1 RG121–RG125 1 RG141–RG142 1 RG161–RG164 1 RG171–RG174 1 RG191–RG193 1 RG211–RG213 1 RG221–RG222 1 RH101–RH102 1 RH111 1 RH121–RH122 1 RJ131–RJ133 1 RJ151–RJ152 1 RJ301–RJ303 1 RJ321–RJ322 1 RJ331–RJ333 1 RR001–RR005 1 RR022–RR025 1 RR201–RR206 1 RR221–RR226 1 RR261–RR262 1 RR264–RR267 1 RR301–RR310 1 RR332 1 RR336 1 RR341–RR345 1 RR361–RR362 1 Variable Group ### Page 24 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 24 of 809 BOEING SERVICE BULLETIN 747-21A2421 RR421 1 RR431–RR432 1 RR441–RR442 1 RR451 1 RR501 1 RR503–RR504 1 RR521–RR522 1 RR526 1 RR531 1 RR551–RR556 1 RR561 1 RR566 1 RS001–RS002 1 RS211–RS212 1 RS221–RS222 1 RS232–RS233 1 RS235–RS241 1 RS251–RS259 1 RS263 1 RS265–RS268 1 RS271–RS276 1 RS292 1 RS301–RS306 1 RS311–RS320 1 RS331–RS333 1 RS341–RS342 1 RS699 1 RS701–RS703 1 RS711–RS713 1 RS721–RS722 1 RS731–RS732 1 RS741–RS743 1 RS751–RS752 1 RS761–RS762 1 RS771 1 RS781–RS782 1 RS786 1 RT021–RT022 1 RT031–RT033 1 Variable Group ### Page 25 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 25 of 809 BOEING SERVICE BULLETIN 747-21A2421 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. C. Reason Some 747 airplanes were assembled with air distribution ducts wrapped with BMS 8-39, polyurethane foam insulation. The fire retardant properties of this polyurethane foam insulation can degrade with age and become a possible fire hazard. BMS 8-39 polyurethane foam insulation meets all flammability requirements, including Federal Aviation Regulation (FAR) 25.853, upon delivery. It has been found that there can be deterioration of these fire retardant properties with age. This, along with dust, dirt and other carbon particulate contamination of the BMS 8-39 insulation on these ducts, adds an available fuel source to the insulation. This can cause the duct assemblies to no longer meet FAR 25.853. This service bulletin provides rework instructions for the affected duct assemblies and for environmental control system (ECS) related parts. Replacement of the old insulation material on the ECS ducts with a new insulation material that meets FAR 25.853 requirements will improve fire safety. The existing BMS 8-39 polyurethane insulation is removed and new BMS 8-300 polyimide foam insulation is installed. There have been two reports of burned BMS 8-39 polyurethane foam insulation on the 767 airplane. Revision 01 - This revision is sent to inform affected operators of changes to the instructions in this service bulletin. The airplane effectivity tables in the Accomplishment Instructions that show the applicable figures and affected part numbers have been changed. Tables that changed are indicated with revision bars. In addition, functional test information has changed to include airplane models 747-SP and 747-SR configurations. The functional tests are also changed to provide an alternate means to apply pressure to the plenum for airplanes without a pressure tap. Fiberglass Tape, Style 116 and Style 120, per BMS 9-3R, were added to the table of Parts and Materials Supplied by the Operator, on Page 32. Fiberglass Tape, Style 120 was added to Appendix "C." The data given in Information Notice 747-21A2421 IN 01, is included in this revision. RT061 1 RT601–RT618 1 RT641–RT647 1 RT691–RT692 1 RT751–RT752 1 Variable Group ### Page 26 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 26 of 809 BOEING SERVICE BULLETIN 747-21A2421 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) duct 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 the service bulletin include: — A Boeing recommended compliance time is given. — 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, 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. Boeing Service Related Problem (SRP) 747-SRP-21-0130 is related to this service bulletin. D. Description Gain access to the affected duct assemblies in the areas as described by the Figure titles. Rework the affected duct assemblies by replacing the existing insulation with BMS 8-300 type II, Grade 0.6 or Grade 5, insulation. Partmark the new assembly. Perform functional tests as required. Revision 01 - More work may be necessary on airplanes changed as shown in the initial release of this service bulletin. See changes to the airplane tables in the Accomplishment Instructions for revision bars. Revision 02 - More work is necessary on airplanes changed as shown in the original issue 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 changes in this service bulletin will not change the Central Maintenance Computer System (CMCS). E. Compliance Boeing recommends this change be accomplished during the next heavy maintenance visit, not to exceed 30,000 flight-hours from the date on this service bulletin. 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. ### Page 27 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 27 of 809 BOEING SERVICE BULLETIN 747-21A2421 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 paragraph 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 task-hour data if necessary. The estimate does not include lost time. These are some examples of lost time: — Time to adjust to the workplace — Time to schedule the work — Time to examine the work — Time to cure the materials — Time to make the parts — Time to find the tools. Man-hours required to accomplish this change are 7.25 hours for each duct. This estimate does not include access and restoration. Functional test requires a crew of two 7.5 man-hours, with an elapsed time of 3.75 hours. H. Weight and Balance Changes None. I. Electrical Load Data Not applicable. J. References 1. Existing Data: a. Engineering Change Memo PRR 85901-18RS b. Service Related Problem (SRP) 747 SRP-21-0130 c. 747 Maintenance Manual (AMM) Subject Chapter 21-23-01, Chapter 25 d. 747-400 Maintenance Manual (AMM) Subject Chapter 21-23-02, Chapter 25 e. Boeing Standard Overhaul Practices Manual (BSOPM) 20-50-10, 20-50-12 ### Page 28 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 28 of 809 BOEING SERVICE BULLETIN 747-21A2421 2. Data supplied with this Service Bulletin: None. ### Page 29 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 29 of 809 BOEING SERVICE BULLETIN 747-21A2421 3. Installation Drawings Used in the Preparation of this Service Bulletin: Drawing Number Title 65B40175 AIR CONDITIONING, FLIGHT DECK, STA 323 - STA 500 65B40176 FLIGHT DECK, AIR CONDITIONING, SECTION 42 65B40947 AIR CONDITIONING - FLIGHT DECK, STA 260 - STA 340 65B41000 DUCT INSTALLATION - CONDITIONED AIR, STATEROOM 65B41010 DUCT INSTALLATION - CONDITIONED AIR, STA 206 TO STA 464 65B41019 DUCT INSTALLATION - ZONE 11, STA 475.75 TO STA 516.0 65B41020 DUCT INSTALLATION - AIR DISTRIBUTION SYSTEM, ZONE 2 65B41034 DUCT INSTALLATION - ZONE 3, AIR DISTRIBUTION SYSTEM 65B41045 DUCT INSTALLATION - ZONE 4, AIR DISTRIBUTION SYSTEM 65B41060 LEFT SIDE RISER INSTALLATION - AIR DISTRIBUTION SYSTEM 65B41187 FAN INSTALLATION - INDIVIDUAL AIR SYSTEM 65B41369 ANEMOSTAT INSTALLATION - STA 165, AIR DISTRIBUTION SYSTEM 65B41565 HUMIDIFIER DUCT INSTALLATION - CREW CABIN, ZONE 1 65B41600 HEAT EXCHANGER INSTALLATION - AIR COND SYSTEM, LOWER LOBE GALLEY 65B41740 INSULATION INSTL - CONDITIONED AIR PLENUM 65B41750 INSULATION INSTL - CONDITIONED AIR MIX BAY , STA 1000 - STA 1265 65B41797 RECIRCULATION FAN INSTALLATION - FLIGHT DECK 65B41916 DUCT INSTALLATION - CONDITIONED AIR MANIFOLD, STA 1000 - STA 1265 65B41965 DUCT INSTALLATION - GASPER AIR SYSTEM, MAIN DECK 65B42050 DUCT INSTALLATION - ZONE 3 FEEDER 65B42111 FLOW DIVIDER INSTALLATION - ZONE B AND C, AIR DISTRIBUTION 65B42246 DUCT INSTALLATION - AIR CONDITIONING SYS, CREW REST COMPARTMENT 65B42323 DUCT INSTALLATION - P8 PANEL COOLING, FLIGHT DECK 65B42350 DUCT INSTALLATION - ZONE 2, STA 456 - STA 516 65B43103 DUCT INSTALLATION - AIR DISTRIBUTION SYSTEM, ZONE 2 65B43146 DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, ZONE D AND E 65B43159 DUCT INSTALLATION - AIR DISTRIBUTION, ZONE 4, FEEDER 65B43340 DUCT INSTALLATION - AIR DISTRIBUTION, ZONE 2 65B43359 DUCT INSTALLATION - AIR DISTRIBUTION SYSTEM, ZONE 3 65B43360 DUCT INSTALLATION - AIR DISTRIBUTION SYSTEM, ZONE 3 65B43394 DUCT INSTALLATION - AIR DISTRIBUTION, UPPER DECK COMPARTMENT 65B43395 DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, LAVATORIES 65B43401 DUCT INSTALLATION - AIR DISTRIBUTION SYS, LOWER AFT CARGO COMPARTMENT 65B43600 DUCT INSTALLATION - CONDITIONED AIR, MAIN DECK CREW REST 65B43639 DUCT INSTALLATION - CONDITIONED AIR, RIGHT HAND CREW REST ### Page 30 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 30 of 809 BOEING SERVICE BULLETIN 747-21A2421 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. 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. K. Publications Affected L. Interchangeability and Intermixability of Parts Refer to Paragraph 2.C., Parts Necessary For Each Airplane, for interchangeability and intermixability information. 65B47894 DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, PASSENGER CABIN 65B48013 DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, UPPER DECK LOUNGE/ FLIGHT DECK 65B48014 DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, PASSENGER CABIN 65B48016 DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, MAIN CABIN 65B48305 HEATING INSTALLATION - PASSENGER CABIN DOOR 65B48428 AIR DISTRIBUTION INSTALLATION - MAIN DECK, CREW REST 65B48446 DUCT INSTALLATION - INDIVIDUAL AIR SYSTEM, LAVATORIES 65B48466 DUCT INSTALLATION - AIR DISTRIBUTION SYSTEM, ZONE 2 65B50200 DUCT INSTALLATION - AIR DISTRIBUTION SYS, PASSENGER CABIN 65BE0277 DUCT INSTALLATION - UPPER DECK, AIR DISTRIBUTION SYSTEM 65BE0366 DUCT INSTALLATION - PLENUM AND RISER AIR, DISTRIBUTION 214U1001 DUCT INSTALLATION CONDITIONED AIR - SECTION 42 214U1004 DUCT INSTALLATION - AIR CONDITIONING SYS CREW REST Publication Chapter-Section 747 Maintenance Manual Chapter 21-23 747 Illustrated Parts Catalog Chapter 21 Drawing Number Title ### Page 31 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 31 of 809 BOEING SERVICE BULLETIN 747-21A2421 2. MATERIAL INFORMATION A. Material - Price and Availability The operator can supply the materials shown in Paragraph 2.C., Parts Necessary For Each Airplane., and Paragraph 2.D., Parts Necessary to Change Spares. As an alternative, operators can purchase the parts from Boeing Spares. This service bulletin does not show the Boeing price and supply data. B. Industry Support Information Boeing warranty remedies are not available for the configuration changes given in this service bulletin. C. Parts Necessary For Each Airplane 1. Kits/Parts: None. ### Page 32 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 32 of 809 BOEING SERVICE BULLETIN 747-21A2421 2. Parts and Materials Supplied by the Operator: NOTE: The parts and materials given below can be used to rework the ducts as required. Refer to Appendix A. for the rework instructions. Part Number/ Specification QTY Name Notes BMS 8-300 Type II, Grade 0.6 or Grade 5, (thickness of 0.25 inches, 0.5 inches and 1.5 inches, 4 feet X 8 feet sheet) (a) Polyimide Foam Insulation (a) (b) (c) BMS 5-157, Type 1, Class 1, Grade B, Form 1, Composition MPVF (Metallized Polyvinyl Fluoride) Widths: 2 inch, 3 inch and 12 inch As required Tape (d) (j) BMS 5-7, Type 2 As required Adhesive (h) BACS38K6 As required Tie Straps BACS38K7 As required Tie Straps BAC5010, Type 98 As required Adhesive (j) Style 116 Per BMS 9-3R, Type C, Class 7, slit and sealed, 3 inches Nominal Width As required Fiberglass Tape (j) Style 120, Per BMS 9-3R, Type D, Class 7,slit and sealed, 3 inches Nominal Width As required Fiberglass Tape (j) G-565 (Furon Temp-R-Tape) As required Fiberglass Tape (g) Venture Tape Number 3959 As required Vinyl Plastic Tape (f) 3M 425 Aluminum Tape (MIL-T-23397) As required Tape (h) (a) The quantity of BMS 8-300 polyimide foam insulation required rework each airplane will vary, depending on the quantity of ducts affected. Approximate estimates are 1,200 square feet for 100 ducts, 600 square feet for 50 ducts and 300 square feet for 25 ducts. (b) The thickness of BMS 8-300 polyimide foam insulation required for each reworked assembly will vary depending on the thickness of the existing BMS 8-39 insulation. Refer to Paragraph 2.C.3., Parts Modified and Reidentified, to determine the required thickness of BMS 8-300 insulation for each assembly being reworked. (c) VENDOR CONTACT INFORMATION Jeheir SA or Boyd Corporation Route DE Saint-Lezin 6236 N.E. 87th Avenue F-49120 Portland, OR, USA 97220 Chemille, France (d) 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. ### Page 33 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 33 of 809 BOEING SERVICE BULLETIN 747-21A2421 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. The thickness of BMS 8-300 polyimide foam insulation required for each reworked assembly will vary depending on the thickness of the existing BMS 8-39 insulation. Refer to the insulation thickness below to determine the required thickness of BMS 8-300 insulation for each assembly being reworked Make the change given in this service bulletin to the Existing Part Numbers on your airplane. The New Part Number is the part number after the change given in the service bulletin is made. (e) VENDOR CONTACT INFORMATION E&H Laminating and Slitting Company 138 Grand Street Paterson, NJ, USA 07501 Facsimile Number (973) 345-3224 (f) VENDOR CONTACT INFORMATION Venture Tape Corporation 30-T Commerce Road Rockland, Maine, USA 02370 (g) VENDOR CONTACT INFORMATION Furon 407 East Street New Haven, CT, USA 06509 (h) VENDOR CONTACT INFORMATION 3M Company 3211 E. Chestnut Exp. Springfield, MO, USA 65802-2592 (j) See the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier data Existing Part Number Insulation Thickness (inches) Name New Part Number 65B40175-12 0.5 Sleeve 65B40175-1012 65B40943-11 0.5 Plenum Assembly 65B40943-1011 65B40943-12 0.5 Plenum Assembly 65B40943-1012 65B40943-16 0.5 Plenum Assembly 65B40943-1016 65B40943-18 0.5 Plenum Assembly 65B40943-1018 65B40947-20 0.5 Sleeve 65B40947-1020 65B40952-5 0.5 Duct Assembly 65B40952-1005 65B40954-12 0.5 Duct Assembly 65B40954-1012 65B40954-13 0.5 Duct Assembly 65B40954-1013 65B40954-15 0.5 Duct Assembly 65B40954-1015 65B40954-16 0.5 Duct Assembly 65B40954-1016 65B40954-17 0.5 Duct Assembly 65B40954-1017 Part Number/ Specification QTY Name Notes ### Page 34 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 34 of 809 BOEING SERVICE BULLETIN 747-21A2421 65B40954-18 0.5 Duct Assembly 65B40954-1018 65B40954-21 0.5 Duct Assembly 65B40954-1021 65B40954-22 0.5 Duct Assembly 65B40954-1022 65B40954-23 0.5 Duct Assembly 65B40954-1023 65B40954-24 0.5 Duct Assembly 65B40954-1024 65B40954-25 0.5 Duct Assembly 65B40954-1025 65B40954-26 0.5 Duct Assembly 65B40954-1026 65B40954-27 0.5 Duct Assembly 65B40954-1027 65B40954-28 0.5 Duct Assembly 65B40954-1028 65B41000-9 0.5 Sleeve 65B41000-1009 65B41005-10 0.5 Duct Assembly 65B41005-1010 65B41005-5 0.5 Duct Assembly 65B41005-1005 65B41005-6 0.5 Duct Assembly 65B41005-1006 65B41005-9 0.5 Duct Assembly 65B41005-1009 65B41006-10 0.5 Duct Assembly 65B41006-1010 65B41006-6 0.5 Duct Assembly 65B41006-1006 65B41006-8 0.5 Duct Assembly 65B41006-1008 65B41007-5 0.5 Duct Assembly 65B41007-1005 65B41007-7 0.5 Duct Assembly 65B41007-1007 65B41009-2 0.5 Duct Assembly 65B41009-1002 65B41011-31 0.5 Duct Assembly 65B41011-1031 65B41011-32 0.5 Duct Assembly 65B41011-1032 65B41011-33 0.5 Duct Assembly 65B41011-1033 65B41011-34 0.5 Duct Assembly 65B41011-1034 65B41011-35 0.5 Duct Assembly 65B41011-1035 65B41011-36 0.5 Duct Assembly 65B41011-1036 65B41011-57 0.5 Duct Assembly 65B41011-1057 65B41011-58 0.5 Duct Assembly 65B41011-1058 65B41011-61 0.5 Duct Assembly 65B41011-1061 65B41011-62 0.5 Duct Assembly 65B41011-1062 65B41011-80 0.5 Duct Assembly 65B41011-1080 65B41011-85 0.5 Duct Assembly 65B41011-1085 65B41011-86 0.5 Duct Assembly 65B41011-1086 65B41011-92 0.5 Duct Assembly 65B41011-1092 65B41011-93 0.5 Duct Assembly 65B41011-1093 65B41012-13 0.5 Duct Assembly 65B41012-1013 65B41012-14 0.5 Duct Assembly 65B41012-1014 65B41012-7 0.5 Duct Assembly 65B41012-1007 Existing Part Number Insulation Thickness (inches) Name New Part Number ### Page 35 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 35 of 809 BOEING SERVICE BULLETIN 747-21A2421 65B41012-8 0.5 Duct Assembly 65B41012-1008 65B41014-15 0.5 Duct Assembly 65B41014-1015 65B41014-16 0.5 Duct Assembly 65B41014-1016 65B41014-5 0.5 Duct Assembly 65B41014-1005 65B41014-6 0.5 Duct Assembly 65B41014-1006 65B41017-10 0.5 Duct Assembly 65B41017-1010 65B41017-13 0.5 Duct Assembly 65B41017-1013 65B41017-14 0.5 Duct Assembly 65B41017-1014 65B41017-23 0.5 Duct Assembly 65B41017-1023 65B41017-26 0.5 Duct Assembly 65B41017-1026 65B41017-28 0.5 Duct Assembly 65B41017-1028 65B41017-5 0.5 Duct Assembly 65B41017-1005 65B41017-6 0.5 Duct Assembly 65B41017-1006 65B41018-3 0.5 Duct Assembly 65B41018-1003 65B41018-4 0.5 Duct Assembly 65B41018-1004 65B41020-20 0.5 Duct Assembly 65B41020-1020 65B41024-32 0.5 Duct Assembly 65B41024-1032 65B41024-33 0.5 Duct Assembly 65B41024-1033 65B41024-34 0.5 Duct Assembly 65B41024-1034 65B41024-35 0.5 Duct Assembly 65B41024-1035 65B41024-58 0.5 Duct Assembly 65B41024-1058 65B41024-62 0.5 Duct Assembly 65B41024-1062 65B41024-67 0.5 Duct Assembly 65B41024-1067 65B41024-68 0.5 Duct Assembly 65B41024-1068 65B41024-72 0.5 Duct Assembly 65B41024-1072 65B41024-73 0.5 Duct Assembly 65B41024-1073 65B41024-74 0.5 Duct Assembly 65B41024-1074 65B41025-19 0.5 Duct Assembly 65B41025-1019 65B41025-21 0.5 Duct Assembly 65B41025-1021 65B41025-25 0.5 Duct Assembly 65B41025-1025 65B41025-26 0.5 Duct Assembly 65B41025-1026 65B41025-35 0.5 Duct Assembly 65B41025-1035 65B41025-36 0.5 Duct Assembly 65B41025-1036 65B41025-39 0.5 Duct Assembly 65B41025-1039 65B41025-47 0.5 Duct Assembly 65B41025-1047 65B41025-48 0.5 Duct Assembly 65B41025-1048 65B41027-10 0.5 Duct Assembly 65B41027-1010 65B41027-7 0.5 Duct Assembly 65B41027-1007 Existing Part Number Insulation Thickness (inches) Name New Part Number ### Page 36 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 36 of 809 BOEING SERVICE BULLETIN 747-21A2421 65B41027-8 0.5 Duct Assembly 65B41027-1008 65B41027-9 0.5 Duct Assembly 65B41027-1009 65B41042-11 0.5 Duct Assembly 65B41042-1011 65B41042-5 0.5 Duct Assembly 65B41042-1005 65B41045-10 0.5 Sleeve 65B41045-1010 65B41045-13 0.5 Duct Assembly 65B41045-1013 65B41045-25 0.5 Sleeve 65B41045-1025 65B41048-14 0.5 Duct Assembly 65B41048-1014 65B41048-17 0.5 Duct Assembly 65B41048-1017 65B41048-20 0.5 Duct Assembly 65B41048-1020 65B41056-8 0.5 Duct Assembly 65B41056-1008 65B41056-9 0.5 Duct Assembly 65B41056-1009 65B41061-10 0.5 Riser Assembly 65B41061-1010 65B41061-22 0.5 Riser Assembly 65B41061-1022 65B41086-11 0.5 Duct Assembly 65B41086-1011 65B41086-12 0.5 Duct Assembly 65B41086-1012 65B41086-5 0.5 Duct Assembly 65B41086-1005 65B41086-6 0.5 Duct Assembly 65B41086-1006 65B41089-10 0.5 Duct Assembly 65B41089-1010 65B41089-5001 0.5 Duct Assembly 65B41089-6001 65B41089-5002 0.5 Duct Assembly 65B41089-6002 65B41089-8 0.5 Duct Assembly 65B41089-1008 65B41125-11 0.25 Duct Assembly 65B41125-1011 65B41125-12 0.25 Duct Assembly 65B41125-1012 65B41127-3 0.5 Duct Assembly 65B41127-1003 65B41127-4 0.5 Duct Assembly 65B41127-1004 65B41128-2 0.5 Duct Assembly 65B41128-1002 65B41188-2 0.5 Duct Assembly 65B41188-1002 65B41189-2 0.5 Duct Assembly 65B41189-1002 65B41190-3 0.5 Duct Assembly 65B41190-1003 65B41191-2 0.5 Duct Assembly 65B41191-1002 65B41192-2 0.5 Duct Assembly 65B41192-1002 65B41193-2 0.5 Duct Assembly 65B41193-1002 65B41194-2 0.5 Duct Assembly 65B41194-1002 65B41229-5 0.5 Duct Assembly 65B41229-1005 65B41229-6 0.5 Duct Assembly 65B41229-1006 65B41230-7 0.25 Duct Assembly 65B41230-1007 65B41230-8 0.25 Duct Assembly 65B41230-1008 Existing Part Number Insulation Thickness (inches) Name New Part Number ### Page 37 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 37 of 809 BOEING SERVICE BULLETIN 747-21A2421 65B41231-1 0.5 Duct Assembly 65B41231-1101 65B41231-9 0.5 Duct Assembly 65B41231-1109 65B41232-2 0.5 Duct Assembly 65B41232-1002 65B41330-6 0.5 Duct Assembly 65B41330-1006 65B41331-12 0.5 Duct Assembly 65B41331-1012 65B41387-2 0.5 Duct Assembly 65B41387-1002 65B41466-4 0.5 Duct Assembly 65B41466-1004 65B41467-4 0.25 Duct Assembly 65B41467-1004 65B41508-100 0.25 Duct Assembly 65B41508-1100 65B41508-101 0.25 Duct Assembly 65B41508-1101 65B41508-103 0.25 Duct Assembly 65B41508-1103 65B41508-133 0.25 Duct Assembly 65B41508-1133 65B41508-136 0.25 Duct Assembly 65B41508-1136 65B41508-137 0.25 Duct Assembly 65B41508-1137 65B41508-73 0.25 Duct Assembly 65B41508-1073 65B41508-74 0.25 Duct Assembly 65B41508-1074 65B41508-75 0.25 Duct Assembly 65B41508-1075 65B41508-77 0.25 Duct Assembly 65B41508-1077 65B41508-78 0.25 Duct Assembly 65B41508-1078 65B41508-79 0.25 Duct Assembly 65B41508-1079 65B41508-80 0.25 Duct Assembly 65B41508-1080 65B41508-81 0.25 Duct Assembly 65B41508-1081 65B41508-82 0.25 Duct Assembly 65B41508-1082 65B41508-83 0.25 Duct Assembly 65B41508-1083 65B41508-84 0.25 Duct Assembly 65B41508-1084 65B41508-85 0.25 Duct Assembly 65B41508-1085 65B41508-86 0.25 Duct Assembly 65B41508-1086 65B41508-87 0.25 Duct Assembly 65B41508-1087 65B41508-88 0.25 Duct Assembly 65B41508-1088 65B41508-89 0.25 Duct Assembly 65B41508-1089 65B41508-90 0.25 Duct Assembly 65B41508-1090 65B41508-91 0.25 Duct Assembly 65B41508-1091 65B41508-92 0.25 Duct Assembly 65B41508-1092 65B41508-93 0.25 Duct Assembly 65B41508-1093 65B41508-94 0.25 Duct Assembly 65B41508-1094 65B41508-95 0.25 Duct Assembly 65B41508-1095 65B41508-96 0.25 Duct Assembly 65B41508-1096 65B41508-97 0.25 Duct Assembly 65B41508-1097 Existing Part Number Insulation Thickness (inches) Name New Part Number ### Page 38 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 38 of 809 BOEING SERVICE BULLETIN 747-21A2421 65B41508-98 0.25 Duct Assembly 65B41508-1098 65B41565-15 0.25 Duct Assembly 65B41565-1015 65B41572-17 0.5 Duct Assembly 65B41572-1017 65B41594-3 0.5 Manifold Assembly 65B41594-1003 65B41594-4 0.5 Manifold Assembly 65B41594-1004 65B41594-7 0.5 Manifold Assembly 65B41594-1007 65B41594-8 0.5 Manifold Assembly 65B41594-1008 65B41597-3 0.5 Duct Assembly 65B41597-1003 65B41597-4 0.5 Duct Assembly 65B41597-1004 65B41598-4 0.5 Duct Assembly 65B41598-1004 65B41598-6 0.5 Duct Assembly 65B41598-1006 65B41598-7 0.5 Duct Assembly 65B41598-1007 65B41609-3 0.5 Duct Assembly 65B41609-1003 65B41609-4 0.5 Duct Assembly 65B41609-1004 65B41609-7 0.5 Duct Assembly 65B41609-1007 65B41638-2 0.5 Duct Assembly 65B41638-1002 65B41726-20 0.5 Duct Assembly 65B41726-1020 65B41740-2 0.5 Blanket Assembly 65B41740-1002 65B41740-3 0.5 Blanket Assembly 65B41740-1003 65B41744-2 0.5 Duct Assembly 65B41744-1002 65B41745-10 0.5 Duct Assembly 65B41745-1010 65B41745-14 0.5 Duct Assembly 65B41745-1014 65B41745-15 0.5 Duct Assembly 65B41745-1015 65B41745-5 0.5 Duct Assembly 65B41745-1005 65B41745-7 0.5 Duct Assembly 65B41745-1007 65B41753-1 0.5 Duct Assembly 65B41753-1001 65B41754-1 0.5 Duct Assembly 65B41754-1001 65B41760-38 0.5 Muffler Assembly 65B41760-1038 65B41788-10 0.5 Duct Assembly 65B41788-1010 65B41788-11 0.5 Duct Assembly 65B41788-1011 65B41788-12 0.5 Duct Assembly 65B41788-1012 65B41788-17 0.5 Duct Assembly 65B41788-1017 65B41788-18 0.5 Duct Assembly 65B41788-1018 65B41788-19 0.5 Duct Assembly 65B41788-1019 65B41788-20 0.5 Duct Assembly 65B41788-1020 65B41788-21 0.5 Duct Assembly 65B41788-1021 65B41788-22 0.5 Duct Assembly 65B41788-1022 65B41788-31 0.5 Duct Assembly 65B41788-1031 Existing Part Number Insulation Thickness (inches) Name New Part Number ### Page 39 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 39 of 809 BOEING SERVICE BULLETIN 747-21A2421 65B41788-32 0.5 Duct Assembly 65B41788-1032 65B41788-33 0.5 Duct Assembly 65B41788-1033 65B41788-35 0.5 Duct Assembly 65B41788-1035 65B41788-9 0.5 Duct Assembly 65B41788-1009 65B41792-10 0.5 Duct Assembly 65B41792-1010 65B41792-13 0.5 Duct Assembly 65B41792-1013 65B41792-9 0.5 Duct Assembly 65B41792-1009 65B41953-4 0.5 Duct Assembly 65B41953-1004 65B41966-1 0.5 Duct Assembly 65B41966-1001 65B41966-24 0.5 Duct Assembly 65B41966-1024 65B41966-3 0.5 Duct Assembly 65B41966-1003 65B41966-4 0.5 Duct Assembly 65B41966-1004 65B41966-5 0.5 Duct Assembly 65B41966-1005 65B41966-6 0.5 Duct Assembly 65B41966-1006 65B41966-7 0.5 Duct Assembly 65B41966-1007 65B41967-1 0.5 Duct Assembly 65B41967-1001 65B41967-2 0.5 Duct Assembly 65B41967-1002 65B41967-3 0.5 Duct Assembly 65B41967-1003 65B41967-4 0.5 Duct Assembly 65B41967-1004 65B41967-5 0.5 Duct Assembly 65B41967-1005 65B41967-6 0.5 Duct Assembly 65B41967-1006 65B41967-7 0.5 Duct Assembly 65B41967-1007 65B41967-8 0.5 Duct Assembly 65B41967-1008 65B41967-9 0.5 Duct Assembly 65B41967-1009 65B41968-1 0.5 Duct Assembly 65B41968-1001 65B41968-2 0.5 Duct Assembly 65B41968-1002 65B41968-3 0.5 Duct Assembly 65B41968-1003 65B41968-30 0.5 Duct Assembly 65B41968-1030 65B41968-39 0.5 Duct Assembly 65B41968-1039 65B41968-4 0.5 Duct Assembly 65B41968-1004 65B41968-42 0.5 Duct Assembly 65B41968-1042 65B41968-45 0.5 Duct Assembly 65B41968-1045 65B41968-5 0.5 Duct Assembly 65B41968-1005 65B41968-6 0.5 Duct Assembly 65B41968-1006 65B41968-7 0.5 Duct Assembly 65B41968-1007 65B41968-8 0.5 Duct Assembly 65B41968-1008 65B41969-2 0.5 Duct Assembly 65B41969-1002 65B41969-9 0.5 Duct Assembly 65B41969-1009 Existing Part Number Insulation Thickness (inches) Name New Part Number ### Page 40 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 40 of 809 BOEING SERVICE BULLETIN 747-21A2421 65B41970-1 0.5 Duct Assembly 65B41970-1001 65B41970-2 0.5 Duct Assembly 65B41970-1002 65B41970-3 0.5 Duct Assembly 65B41970-1003 65B41970-4 0.5 Duct Assembly 65B41970-1004 65B42127-1 0.5 Duct Assembly 65B42127-1001 65B42127-2 0.5 Duct Assembly 65B42127-1002 65B42127-3 0.5 Duct Assembly 65B42127-1003 65B42127-4 0.5 Duct Assembly 65B42127-1004 65B42128-1 0.5 Duct Assembly 65B42128-1001 65B42128-2 0.5 Duct Assembly 65B42128-1002 65B42128-3 0.5 Duct Assembly 65B42128-1003 65B42128-4 0.5 Duct Assembly 65B42128-1004 65B42128-5 0.5 Duct Assembly 65B42128-1005 65B42130-15 0.5 Duct Assembly 65B42130-1015 65B42130-4 0.5 Duct Assembly 65B42130-1004 65B42130-8 0.5 Duct Assembly 65B42130-1008 65B42131-5 0.5 Duct Assembly 65B42131-1005 65B42196-1 0.5 Duct Assembly 65B42196-1001 65B42196-4 0.5 Duct Assembly 65B42196-1004 65B42196-9 0.5 Duct Assembly 65B42196-1009 65B42274-1 0.5 Duct Assembly 65B42274-1001 65B42274-2 0.5 Duct Assembly 65B42274-1002 65B42274-3 0.5 Duct Assembly 65B42274-1003 65B42323-5 0.5 Duct Assembly 65B42323-1005 65B42330-1 0.5 Duct Assembly 65B42330-1001 65B42330-2 0.5 Duct Assembly 65B42330-1002 65B42331-1 0.5 Duct Assembly 65B42331-1001 65B42331-11 0.5 Duct Assembly 65B42331-1011 65B42331-12 0.5 Duct Assembly 65B42331-1012 65B42331-2 0.5 Duct Assembly 65B42331-1002 65B42331-3 0.5 Duct Assembly 65B42331-1003 65B42331-4 0.5 Duct Assembly 65B42331-1004 65B42516-1 0.5 Duct Assembly 65B42516-1001 65B42577-7 0.5 Duct Assembly 65B42577-1007 65B42577-8 0.5 Duct Assembly 65B42577-1008 65B42578-1 0.5 Duct Assembly 65B42578-1001 65B42578-2 0.5 Duct Assembly 65B42578-1002 65B42579-1 0.5 Duct Assembly 65B42579-1001 Existing Part Number Insulation Thickness (inches) Name New Part Number ### Page 41 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 41 of 809 BOEING SERVICE BULLETIN 747-21A2421 65B42579-4 0.5 Duct Assembly 65B42579-1004 65B42579-6 0.5 Duct Assembly 65B42579-1006 65B42580-1 0.5 Duct Assembly 65B42580-1001 65B42580-2 0.5 Duct Assembly 65B42580-1002 65B42585-1 0.5 Duct Assembly 65B42585-1001 65B42585-2 0.5 Duct Assembly 65B42585-1002 65B42600-10 0.5 Valve Assembly 65B42600-1010 65B42600-16 0.5 Valve Assembly 65B42600-1016 65B42600-19 0.5 Valve Assembly 65B42600-1019 65B42600-2 0.5 Valve Assembly 65B42600-1002 65B42600-7 0.5 Valve Assembly 65B42600-1007 65B42600-9 0.5 Valve Assembly 65B42600-1009 65B42645-12 0.5 Duct Assembly 65B42645-1012 65B42696-1 0.5 Duct Assembly 65B42696-1001 65B42877-3 0.5 Duct Assembly 65B42877-1003 65B43004-5 0.25 Duct Assembly 65B43004-1005 65B43004-9 0.25 Duct Assembly 65B43004-1009 65B43005-1 0.25 Duct Assembly 65B43005-1001 65B43005-2 0.25 Duct Assembly 65B43005-1002 65B43005-3 0.25 Duct Assembly 65B43005-1003 65B43036-15 0.5 Duct Assembly 65B43036-1015 65B43036-16 0.5 Duct Assembly 65B43036-1016 65B43039-1 0.25 Duct Assembly 65B43039-1001 65B43040-13 0.25 Duct Assembly 65B43040-1013 65B43043-1 0.5 Duct Assembly 65B43043-1001 65B43043-2 0.5 Duct Assembly 65B43043-1002 65B43043-7 0.5 Duct Assembly 65B43043-1007 65B43048-1 0.5 Duct Assembly 65B43048-1001 65B43048-5 0.5 Duct Assembly 65B43048-1005 65B43073-1 0.5 Duct Assembly 65B43073-1001 65B43077-6 0.5 Duct Assembly 65B43077-1006 65B43101-1 0.5 Duct Assembly 65B43101-1001 65B43147-1 0.5 Duct Assembly 65B43147-1001 65B43147-2 0.5 Duct Assembly 65B43147-1002 65B43147-3 0.5 Duct Assembly 65B43147-1003 65B43147-4 0.5 Duct Assembly 65B43147-1004 65B43148-1 0.5 Duct Assembly 65B43148-1001 65B43349-1 0.5 Duct Assembly 65B43349-1001 Existing Part Number Insulation Thickness (inches) Name New Part Number ### Page 42 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 42 of 809 BOEING SERVICE BULLETIN 747-21A2421 65B43349-16 0.5 Duct Assembly 65B43349-1016 65B43349-19 0.5 Duct Assembly 65B43349-1019 65B43349-2 0.5 Duct Assembly 65B43349-1002 65B43361-5 0.5 Duct Assembly 65B43361-1005 65B43361-6 0.5 Duct Assembly 65B43361-1006 65B43377-1 0.5 Duct Assembly 65B43377-1001 65B43378-1 0.5 Duct Assembly 65B43378-1101 65B43378-6 0.5 Duct Assembly 65B43378-1106 65B43378-8 0.5 Duct Assembly 65B43378-1108 65B43389-1 0.5 Duct Assembly 65B43389-1001 65B43389-14 0.5 Duct Assembly 65B43389-1014 65B43389-4 0.5 Duct Assembly 65B43389-1004 65B43390-1 0.5 Duct Assembly 65B43390-1001 65B43390-4 0.5 Duct Assembly 65B43390-1004 65B43390-5 0.5 Duct Assembly 65B43390-1005 65B43392-15 0.5 Duct Assembly 65B43392-1015 65B43392-16 0.5 Duct Assembly 65B43392-1016 65B43396-1 0.25 Duct Assembly 65B43396-1001 65B43396-2 0.25 Duct Assembly 65B43396-1002 65B43396-3 0.25 Duct Assembly 65B43396-1003 65B43396-4 0.25 Duct Assembly 65B43396-1004 65B43396-5 0.25 Duct Assembly 65B43396-1005 65B43396-7 0.25 Duct Assembly 65B43396-1007 65B43402-1 0.5 Duct Assembly 65B43402-1001 65B43424-1 0.5 Duct Assembly 65B43424-1001 65B43456-1 0.5 Duct Assembly 65B43456-1001 65B43456-2 0.5 Duct Assembly 65B43456-1002 65B43456-25 0.5 Duct Assembly 65B43456-1025 65B43456-28 0.5 Duct Assembly 65B43456-1028 65B43456-3 0.5 Duct Assembly 65B43456-1003 65B43456-34 0.5 Duct Assembly 65B43456-1034 65B43456-37 0.5 Duct Assembly 65B43456-1037 65B43456-4 0.5 Duct Assembly 65B43456-1004 65B43456-40 0.5 Duct Assembly 65B43456-1040 65B43456-43 0.5 Duct Assembly 65B43456-1043 65B43456-46 0.5 Duct Assembly 65B43456-1046 65B43456-49 0.5 Duct Assembly 65B43456-1049 65B43456-5 0.5 Duct Assembly 65B43456-1005 Existing Part Number Insulation Thickness (inches) Name New Part Number ### Page 43 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 43 of 809 BOEING SERVICE BULLETIN 747-21A2421 65B43456-52 0.5 Duct Assembly 65B43456-1052 65B43456-60 0.5 Duct Assembly 65B43456-1060 65B43456-7 0.5 Duct Assembly 65B43456-1007 65B43456-8 0.5 Duct Assembly 65B43456-1008 65B43457-11 0.5 Duct Assembly 65B43457-1011 65B43458-1 0.5 Duct Assembly 65B43458-1001 65B43468-1 0.5 Duct Assembly 65B43468-1001 65B43468-2 0.5 Duct Assembly 65B43468-1002 65B43469-1 0.5 Duct Assembly 65B43469-1001 65B43469-2 0.5 Duct Assembly 65B43469-1002 65B43470-1 0.5 Duct Assembly 65B43470-1001 65B43470-2 0.5 Duct Assembly 65B43470-1002 65B43471-1 0.5 Duct Assembly 65B43471-1001 65B43471-2 0.5 Duct Assembly 65B43471-1002 65B43472-1 0.5 Duct Assembly 65B43472-1001 65B43472-2 0.5 Duct Assembly 65B43472-1002 65B43473-1 0.5 Duct Assembly 65B43473-1001 65B43474-1 0.5 Duct Assembly 65B43474-1001 65B43477-1 0.5 Duct Assembly 65B43477-1001 65B43480-1 0.5 Duct Assembly 65B43480-1001 65B43481-1 0.5 Duct Assembly 65B43481-1001 65B43486-1 0.5 Duct Assembly 65B43486-1001 65B43487-1 0.5 Duct Assembly 65B43487-1001 65B43488-1 0.5 Duct Assembly 65B43488-1001 65B43493-1 0.5 Duct Assembly 65B43493-1001 65B43493-2 0.5 Duct Assembly 65B43493-1002 65B43502-1 0.5 Duct Assembly 65B43502-1001 65B43502-13 0.5 Duct Assembly 65B43502-1013 65B43502-17 0.5 Duct Assembly 65B43502-1017 65B43502-23 0.5 Duct Assembly 65B43502-1023 65B43502-27 0.5 Duct Assembly 65B43502-1027 65B43502-32 0.5 Duct Assembly 65B43502-1032 65B43502-35 0.5 Duct Assembly 65B43502-1035 65B43502-38 0.5 Duct Assembly 65B43502-1038 65B43502-4 0.5 Duct Assembly 65B43502-1004 65B43502-44 0.5 Duct Assembly 65B43502-1044 65B43502-46 0.5 Duct Assembly 65B43502-1046 65B43506-1 0.5 Duct Assembly 65B43506-1001 Existing Part Number Insulation Thickness (inches) Name New Part Number ### Page 44 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 44 of 809 BOEING SERVICE BULLETIN 747-21A2421 65B43506-12 0.5 Duct Assembly 65B43506-1012 65B43506-15 0.5 Duct Assembly 65B43506-1015 65B43506-16 0.5 Duct Assembly 65B43506-1016 65B43506-20 0.5 Duct Assembly 65B43506-1020 65B43506-24 0.5 Duct Assembly 65B43506-1024 65B43506-28 0.5 Duct Assembly 65B43506-1028 65B43506-8 0.5 Duct Assembly 65B43506-1008 65B43576-1 0.25 Duct Assembly 65B43576-1001 65B43576-2 0.25 Duct Assembly 65B43576-1002 65B43576-3 0.25 Duct Assembly 65B43576-1003 65B43579-2 0.25 Duct Assembly 65B43579-1002 65B43579-27 0.25 Duct Assembly 65B43579-1027 65B43579-3 0.25 Duct Assembly 65B43579-1003 65B43579-30 0.25 Duct Assembly 65B43579-1030 65B43579-35 0.25 Duct Assembly 65B43579-1035 65B43579-4 0.25 Duct Assembly 65B43579-1004 65B43579-40 0.25 Duct Assembly 65B43579-1040 65B43579-41 0.5 Duct Assembly 65B43579-1041 65B43579-44 0.5 Duct Assembly 65B43579-1044 65B43579-49 0.25 Duct Assembly 65B43579-1049 65B43579-5 0.5 Duct Assembly 65B43579-1005 65B43579-54 0.25 Duct Assembly 65B43579-1054 65B43579-6 0.5 Duct Assembly 65B43579-1006 65B43588-1 0.5 Duct Assembly 65B43588-1001 65B43588-4 0.5 Duct Assembly 65B43588-1004 65B43590-1 0.5 Duct Assembly 65B43590-1001 65B43627-1 0.5 Duct Assembly 65B43627-1001 65B43627-2 0.5 Duct Assembly 65B43627-1002 65B47863-1 0.25 Duct Assembly 65B47863-1001 65B47863-2 0.25 Duct Assembly 65B47863-1002 65B47863-3 0.25 Duct Assembly 65B47863-1003 65B47863-4 0.25 Duct Assembly 65B47863-1004 65B47863-5 0.25 Duct Assembly 65B47863-1005 65B47863-6 0.25 Duct Assembly 65B47863-1006 65B47863-7 0.25 Duct Assembly 65B47863-1007 65B47863-8 0.25 Duct Assembly 65B47863-1008 65B47863-9 0.25 Duct Assembly 65B47863-1009 65B47868-1 0.5 Duct Assembly 65B47868-1001 Existing Part Number Insulation Thickness (inches) Name New Part Number ### Page 45 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 45 of 809 BOEING SERVICE BULLETIN 747-21A2421 65B47868-2 0.5 Duct Assembly 65B47868-1002 65B47868-3 0.5 Duct Assembly 65B47868-1003 65B47868-4 0.5 Duct Assembly 65B47868-1004 65B47868-41 0.5 Duct Assembly 65B47868-1041 65B47868-49 0.5 Duct Assembly 65B47868-1049 65B47868-7 0.5 Duct Assembly 65B47868-1007 65B47868-8 0.5 Duct Assembly 65B47868-1008 65B47868-9 0.5 Duct Assembly 65B47868-1009 65B47869-1 0.5 Duct Assembly 65B47869-1001 65B47876-1 0.5 Duct Assembly 65B47876-1001 65B47876-2 0.5 Duct Assembly 65B47876-1002 65B47876-3 0.5 Duct Assembly 65B47876-1003 65B47876-5 0.5 Duct Assembly 65B47876-1005 65B47876-7 0.5 Duct Assembly 65B47876-1007 65B47887-1 0.5 Duct Assembly 65B47887-1001 65B47887-10 0.5 Duct Assembly 65B47887-1010 65B47887-11 0.5 Duct Assembly 65B47887-1011 65B47887-4 0.5 Duct Assembly 65B47887-1004 65B47952-1 0.5 Duct Assembly 65B47952-1001 65B47952-10 0.5 Duct Assembly 65B47952-1010 65B47952-11 0.5 Duct Assembly 65B47952-1011 65B47952-2 0.5 Duct Assembly 65B47952-1002 65B47960-1 0.5 Duct Assembly 65B47960-1001 65B47960-2 0.5 Duct Assembly 65B47960-1002 65B48062-1 0.5 Duct Assembly 65B48062-1001 65B48062-2 0.5 Duct Assembly 65B48062-1002 65B48062-3 0.5 Duct Assembly 65B48062-1003 65B48062-33 0.5 Duct Assembly 65B48062-1033 65B48062-34 0.5 Duct Assembly 65B48062-1034 65B48062-35 0.5 Duct Assembly 65B48062-1035 65B48062-36 0.5 Duct Assembly 65B48062-1036 65B48062-37 0.5 Duct Assembly 65B48062-1037 65B48062-38 0.5 Duct Assembly 65B48062-1038 65B48062-5 0.5 Duct Assembly 65B48062-1005 65B48062-52 0.5 Duct Assembly 65B48062-1052 65B48062-53 0.5 Duct Assembly 65B48062-1053 65B48062-57 0.5 Duct Assembly 65B48062-1057 65B48062-6 0.5 Duct Assembly 65B48062-1006 Existing Part Number Insulation Thickness (inches) Name New Part Number ### Page 46 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 46 of 809 BOEING SERVICE BULLETIN 747-21A2421 65B48062-7 0.5 Duct Assembly 65B48062-1007 65B48062-75 0.5 Duct Assembly 65B48062-1075 65B48062-79 0.5 Duct Assembly 65B48062-1079 65B48062-83 0.5 Duct Assembly 65B48062-1083 65B48062-87 0.5 Duct Assembly 65B48062-1087 65B48062-91 0.5 Duct Assembly 65B48062-1091 65B48062-95 0.5 Duct Assembly 65B48062-1095 65B48129-1 0.5 Duct Assembly 65B48129-1001 65B48129-2 0.5 Duct Assembly 65B48129-1002 65B48129-3 0.5 Duct Assembly 65B48129-1003 65B48129-4 0.5 Duct Assembly 65B48129-1004 65B48129-5 0.5 Duct Assembly 65B48129-1005 65B48129-6 0.5 Duct Assembly 65B48129-1006 65B48130-1 0.5 Duct Assembly 65B48130-1001 65B48130-12 0.5 Duct Assembly 65B48130-1012 65B48130-18 0.5 Duct Assembly 65B48130-1018 65B48130-20 0.5 Duct Assembly 65B48130-1020 65B48130-22 0.5 Duct Assembly 65B48130-1022 65B48132-4 0.5 Filter Assembly 65B48132-1004 65B48135-1 0.5 Duct Assembly 65B48135-1001 65B48135-2 0.5 Duct Assembly 65B48135-1002 65B48140-1 0.5 Filter Case Assembly 65B48140-1001 65B48148-1 0.5 Filter Assembly 65B48148-1001 65B48154-1 0.5 Filter Case Assembly 65B48154-1001 65B48225-1 0.5 Duct Assembly 65B48225-1001 65B48226-15 0.5 Duct Assembly 65B48226-1015 65B48226-2 0.5 Duct Assembly 65B48226-1002 65B48258-1 0.25 Duct Assembly 65B48258-1001 65B48258-10 0.25 Duct Assembly 65B48258-1010 65B48258-12 0.25 Duct Assembly 65B48258-1012 65B48258-15 0.25 Duct Assembly 65B48258-1015 65B48258-18 0.25 Duct Assembly 65B48258-1018 65B48258-2 0.25 Duct Assembly 65B48258-1002 65B48258-21 0.25 Duct Assembly 65B48258-1021 65B48262-1 0.5 Duct Assembly 65B48262-1001 65B48272-1 0.25 Duct Assembly 65B48272-1001 65B48272-8 0.25 Duct Assembly 65B48272-1008 65B48272-9 0.25 Duct Assembly 65B48272-1009 Existing Part Number Insulation Thickness (inches) Name New Part Number ### Page 47 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 47 of 809 BOEING SERVICE BULLETIN 747-21A2421 65B48273-1 0.25 Duct Assembly 65B48273-1001 65B48273-4 0.25 Duct Assembly 65B48273-1004 65B48276-13 0.25 Duct Assembly 65B48276-1013 65B48276-7 0.25 Duct Assembly 65B48276-1007 65B48285-1 0.25 Duct Assembly 65B48285-1001 65B48285-10 0.25 Duct Assembly 65B48285-1010 65B48285-13 0.25 Duct Assembly 65B48285-1013 65B48285-16 0.25 Duct Assembly 65B48285-1016 65B48285-19 0.25 Duct Assembly 65B48285-1019 65B48285-2 0.25 Duct Assembly 65B48285-1002 65B48285-23 0.25 Duct Assembly 65B48285-1023 65B48299-1 0.5 Outlet Assembly 65B48299-1001 65B48309-1 0.25 Duct Assembly 65B48309-1001 65B48309-4 0.25 Duct Assembly 65B48309-1004 65B48312-14 0.25 Duct Assembly 65B48312-1014 65B48312-17 0.25 Duct Assembly 65B48312-1017 65B48312-4 0.25 Duct Assembly 65B48312-1004 65B48312-9 0.25 Duct Assembly 65B48312-1009 65B48447-2 0.25 Duct Assembly 65B48447-1002 65B48447-3 0.25 Duct Assembly 65B48447-1003 65B48447-4 0.25 Duct Assembly 65B48447-1004 65B48447-44 0.25 Duct Assembly 65B48447-1044 65B48447-47 0.25 Duct Assembly 65B48447-1047 65B48447-5 0.25 Duct Assembly 65B48447-1005 65B48447-50 0.25 Duct Assembly 65B48447-1050 65B48447-58 0.25 Duct Assembly 65B48447-1058 65B48447-6 0.25 Duct Assembly 65B48447-1006 65B48447-64 0.25 Duct Assembly 65B48447-1064 65B48447-68 0.25 Duct Assembly 65B48447-1068 65B48447-71 0.25 Duct Assembly 65B48447-1071 65B48447-81 0.25 Duct Assembly 65B48447-1081 65B48447-85 0.25 Duct Assembly 65B48447-1085 65B48447-90 0.25 Duct Assembly 65B48447-1090 65B48447-94 0.25 Duct Assembly 65B48447-1094 65B48457-1 0.5 Duct Assembly 65B48457-1001 65B48457-7 0.5 Duct Assembly 65B48457-1007 65B48457-9 0.5 Duct Assembly 65B48457-1009 65B48458-1 0.5 Transition Assembly 65B48458-1001 Existing Part Number Insulation Thickness (inches) Name New Part Number ### Page 48 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 48 of 809 BOEING SERVICE BULLETIN 747-21A2421 65B48458-2 0.5 Transition Assembly 65B48458-1002 65B48459-1 0.5 Duct Assembly 65B48459-1001 65B48459-3 0.5 Duct Assembly 65B48459-1003 65B48459-7 0.5 Duct Assembly 65B48459-1007 65B48460-1 0.5 Transition Assembly 65B48460-1001 65B48460-5 0.5 Transition Assembly 65B48460-1005 65B48461-1 0.5 Transition Assembly 65B48461-1001 65B48462-1 0.5 Duct Assembly 65B48462-1001 65B48467-25 0.5 Duct Assembly 65B48467-1025 65B48467-32 0.5 Duct Assembly 65B48467-1032 65B48467-33 0.5 Duct Assembly 65B48467-1033 65B48467-34 0.5 Duct Assembly 65B48467-1034 65B48467-41 0.5 Duct Assembly 65B48467-1041 65B48467-42 0.5 Duct Assembly 65B48467-1042 65B48467-44 0.5 Duct Assembly 65B48467-1044 65B48467-45 0.5 Duct Assembly 65B48467-1045 65B48467-50 0.5 Duct Assembly 65B48467-1050 65B48482-1 0.5 Duct Assembly 65B48482-1001 65B48482-15 0.5 Duct Assembly 65B48482-1015 65B48482-16 0.5 Duct Assembly 65B48482-1016 65B48482-2 0.5 Duct Assembly 65B48482-1002 65B48482-3 0.5 Duct Assembly 65B48482-1003 65B48482-64 0.5 Duct Assembly 65B48482-1064 65B48482-65 0.5 Duct Assembly 65B48482-1065 65B48482-66 0.5 Duct Assembly 65B48482-1066 65B48482-67 0.5 Duct Assembly 65B48482-1067 65B48482-68 0.5 Duct Assembly 65B48482-1068 65B48482-69 0.5 Duct Assembly 65B48482-1069 65B48482-7 0.5 Duct Assembly 65B48482-1007 65B48482-70 0.5 Duct Assembly 65B48482-1070 65B48482-71 0.5 Duct Assembly 65B48482-1071 65B48482-72 0.5 Duct Assembly 65B48482-1072 65B48482-73 0.5 Duct Assembly 65B48482-1073 65B48482-74 0.5 Duct Assembly 65B48482-1074 65B48482-75 0.5 Duct Assembly 65B48482-1075 65B48482-77 0.5 Duct Assembly 65B48482-1077 65B48482-82 0.5 Duct Assembly 65B48482-1082 65B48482-85 0.5 Duct Assembly 65B48482-1085 Existing Part Number Insulation Thickness (inches) Name New Part Number ### Page 49 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 49 of 809 BOEING SERVICE BULLETIN 747-21A2421 65B48482-89 0.5 Duct Assembly 65B48482-1089 65B48482-90 0.5 Duct Assembly 65B48482-1090 65B48482-93 0.5 Duct Assembly 65B48482-1093 65B48482-95 0.5 Duct Assembly 65B48482-1095 65B48482-96 0.5 Duct Assembly 65B48482-1096 65B48482-99 0.5 Duct Assembly 65B48482-1099 65B48531-1 0.5 Duct Assembly 65B48531-1001 65B48531-3 0.5 Duct Assembly 65B48531-1003 65B48531-4 0.5 Duct Assembly 65B48531-1004 65B48600-1 0.5 Duct Assembly 65B48600-1001 65B48600-14 0.5 Duct Assembly 65B48600-1014 65B48600-17 0.5 Duct Assembly 65B48600-1017 65B48600-29 0.5 Duct Assembly 65B48600-1029 65B48600-4 0.5 Duct Assembly 65B48600-1004 65B48600-8 0.5 Duct Assembly 65B48600-1008 65B48601-13 0.25 Transition Assembly 65B48601-1013 65B48601-16 0.5 Duct Assembly 65B48601-1016 65B48601-4 0.5 Duct Assembly 65B48601-1004 65B48601-7 0.5 Duct Assembly 65B48601-1007 65B48602-1 0.25 Duct Assembly 65B48602-1001 65B48602-4 0.25 Duct Assembly 65B48602-1004 65B48604-1 0.5 Duct Assembly 65B48604-1001 65B48605-18 0.25 Duct Assembly 65B48605-1018 65B48605-19 0.25 Duct Assembly 65B48605-1019 65B48605-5 0.25 Duct Assembly 65B48605-1005 65B48607-1 0.25 Duct Assembly 65B48607-1001 65B48607-10 0.25 Duct Assembly 65B48607-1010 65B48607-13 0.25 Duct Assembly 65B48607-1013 65B48607-16 0.25 Duct Assembly 65B48607-1016 65B48607-19 0.25 Duct Assembly 65B48607-1019 65B48607-22 0.25 Duct Assembly 65B48607-1022 65B48607-25 0.25 Duct Assembly 65B48607-1025 65B48607-28 0.25 Duct Assembly 65B48607-1028 65B48607-31 0.25 Duct Assembly 65B48607-1031 65B48607-4 0.25 Duct Assembly 65B48607-1004 65B48607-7 0.25 Duct Assembly 65B48607-1007 65B48609-1 0.25 Duct Assembly 65B48609-1001 65B48609-5 0.25 Duct Assembly 65B48609-1005 Existing Part Number Insulation Thickness (inches) Name New Part Number ### Page 50 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 50 of 809 BOEING SERVICE BULLETIN 747-21A2421 65B48684-1 0.5 Duct Assembly 65B48684-1001 65B48684-2 0.5 Duct Assembly 65B48684-1002 65B50204-5 0.25 Duct Assembly 65B50204-1005 65B50204-6 0.25 Duct Assembly 65B50204-1006 65B50205-13 0.25 Duct Assembly 65B50205-1013 65B50205-14 0.25 Duct Assembly 65B50205-1014 65B50205-17 0.25 Duct Assembly 65B50205-1017 65B50205-18 0.25 Duct Assembly 65B50205-1018 65B50205-23 0.25 Duct Assembly 65B50205-1023 65B50205-26 0.25 Duct Assembly 65B50205-1026 65B50205-27 0.25 Duct Assembly 65B50205-1027 65B50205-32 0.25 Duct Assembly 65B50205-1032 65B50206-11 0.25 Duct Assembly 65B50206-1011 65B50206-9 0.25 Duct Assembly 65B50206-1009 65B50207-6 0.25 Duct Assembly 65B50207-1006 65B50208-5 0.25 Duct Assembly 65B50208-1005 65B50208-8 0.25 Duct Assembly 65B50208-1008 65B50210-5 0.25 Duct Assembly 65B50210-1005 65B50210-7 0.25 Duct Assembly 65B50210-1007 65B50211-10 0.25 Duct Assembly 65B50211-1010 65B50211-9 0.25 Duct Assembly 65B50211-1009 65B50212-5 0.25 Duct Assembly 65B50212-1005 65B50212-7 0.25 Duct Assembly 65B50212-1007 65B50213-9 0.25 Duct Assembly 65B50213-1009 65B50214-5 0.25 Duct Assembly 65B50214-1005 65B50215-11 0.25 Duct Assembly 65B50215-1011 65B50215-9 0.25 Duct Assembly 65B50215-1009 65B50216-7 0.25 Duct Assembly 65B50216-1007 65B50217-10 0.25 Duct Assembly 65B50217-1010 65B50217-11 0.25 Duct Assembly 65B50217-1011 65B50217-5002 0.25 Duct Assembly 65B50217-6002 65B50218-3 0.25 Duct Assembly 65B50218-1003 69B40145-10 0.5 Duct Assembly 69B40145-1110 69B40145-27 0.5 Duct Assembly 69B40145-1127 69B40145-7 0.5 Duct Assembly 69B40145-1107 69B40145-8 0.5 Duct Assembly 69B40145-1108 69B40146-5 0.5 Duct Assembly 69B40146-1005 69B40147-12 0.5 Duct Assembly 69B40147-1012 Existing Part Number Insulation Thickness (inches) Name New Part Number ### Page 51 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 51 of 809 BOEING SERVICE BULLETIN 747-21A2421 69B40147-13 0.5 Duct Assembly 69B40147-1013 69B40147-16 0.5 Duct Assembly 69B40147-1016 69B40147-30 0.5 Duct Assembly 69B40147-1030 69B40147-31 0.5 Duct Assembly 69B40147-1031 69B40147-8 0.5 Duct Assembly 69B40147-1008 69B41005-9 0.5 Duct Assembly 69B41005-1009 69B41029-11 0.5 Duct Assembly 69B41029-1011 69B41029-12 0.5 Duct Assembly 69B41029-1012 69B41029-3 0.5 Duct Assembly 69B41029-1003 69B41029-4 0.5 Duct Assembly 69B41029-1004 69B41088-15 0.5 Duct Assembly 69B41088-1015 69B41088-16 0.5 Duct Assembly 69B41088-1016 69B41088-18 0.5 Duct Assembly 69B41088-1018 69B41089-7 0.5 Duct Assembly 69B41089-1007 69B41089-9 0.5 Duct Assembly 69B41089-1009 69B41095-12 0.5 Duct Assembly 69B41095-1112 69B41095-13 0.5 Duct Assembly 69B41095-1113 69B41095-15 0.5 Duct Assembly 69B41095-1115 69B41096-11 0.5 Duct Assembly 69B41096-1111 69B41096-12 0.5 Duct Assembly 69B41096-1112 69B41096-5 0.5 Duct Assembly 69B41096-1105 69B41096-8 0.5 Duct Assembly 69B41096-1108 69B41209-3 0.5 Riser Crossover Assembly 69B41209-1003 69B41209-5 0.5 Riser Crossover Assembly 69B41209-1005 69B41209-7 0.5 Riser Crossover Assembly 69B41209-1007 69B41209-8 0.5 Riser Crossover Assembly 69B41209-1008 69B41210-3 0.5 Duct Assembly 69B41210-1003 69B41210-4 0.5 Riser Crossover Assembly 69B41210-1004 69B41210-6 0.5 Duct Assembly 69B41210-1006 69B41211-10 0.5 Riser Crossover Assembly 69B41211-1010 69B41211-3 0.5 Riser Crossover Assembly 69B41211-1003 69B41211-5 0.5 Riser Crossover Assembly 69B41211-1005 69B41211-6 0.5 Riser Crossover Assembly 69B41211-1006 69B41211-7 0.5 Duct Assembly 69B41211-1007 69B41212-5 0.5 Riser Crossover Assembly 69B41212-1005 69B41212-7 0.5 Riser Crossover Assembly 69B41212-1007 69B41212-8 0.5 Riser Crossover Assembly 69B41212-1008 69B41212-9 0.5 Riser Crossover Assembly 69B41212-1009 Existing Part Number Insulation Thickness (inches) Name New Part Number ### Page 52 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 52 of 809 BOEING SERVICE BULLETIN 747-21A2421 69B41652-3 0.25 Duct Assembly 69B41652-1003 69B41655-28 0.5 Duct Assembly 69B41655-1028 69B41655-29 0.5 Duct Assembly 69B41655-1029 69B41655-30 0.5 Duct Assembly 69B41655-1030 69B41655-31 0.5 Duct Assembly 69B41655-1031 69B41655-32 0.5 Duct Assembly 69B41655-1032 69B41655-38 0.5 Duct Assembly 69B41655-1038 69B41655-39 0.5 Duct Assembly 69B41655-1039 69B41655-40 0.5 Duct Assembly 69B41655-1040 69B41655-41 0.5 Duct Assembly 69B41655-1041 69B41655-42 0.5 Duct Assembly 69B41655-1042 69B41659-6 0.5 Duct Assembly 69B41659-1006 69B41660-5 0.5 Flow Divider Assembly 69B41660-1005 69B41660-6 0.5 Flow Divider Assembly 69B41660-1006 69B41661-3 0.5 Duct Assembly 69B41661-1003 69B41838-4 0.25 Elbow Assembly 69B41838-1004 69B42017-2 0.5 Duct Assembly 69B42017-1002 69B42017-4 0.5 Duct Assembly 69B42017-1004 69B42207-6 0.5 Duct Assembly 69B42207-1006 69B42207-7 0.5 Duct Assembly 69B42207-1007 69B42207-8 0.5 Duct Assembly 69B42207-1008 69B42211-12 0.5 Duct Assembly 69B42211-1012 69B42211-2 0.5 Duct Assembly 69B42211-1002 69B42211-5 0.5 Duct Assembly 69B42211-1005 69B42211-6 0.5 Duct Assembly 69B42211-1006 69B42211-8 0.5 Duct Assembly 69B42211-1008 69B42211-9 0.5 Duct Assembly 69B42211-1009 69B42213-2 0.5 Duct Assembly 69B42213-1102 69B42214-2 0.5 Duct Assembly 69B42214-1002 69B42215-11 0.5 Duct Assembly 69B42215-1011 69B42215-13 0.5 Duct Assembly 69B42215-1013 69B42215-15 0.5 Duct Assembly 69B42215-1015 69B42215-23 0.5 Duct Assembly 69B42215-1023 69B42215-27 0.5 Duct Assembly 69B42215-1027 69B42215-3 0.5 Duct Assembly 69B42215-1003 69B42215-31 0.5 Duct Assembly 69B42215-1031 69B42215-33 0.5 Duct Assembly 69B42215-1033 69B42215-35 0.5 Duct Assembly 69B42215-1035 Existing Part Number Insulation Thickness (inches) Name New Part Number ### Page 53 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 53 of 809 BOEING SERVICE BULLETIN 747-21A2421 69B42215-37 0.5 Duct Assembly 69B42215-1037 69B42215-39 0.5 Duct Assembly 69B42215-1039 69B42215-4 0.5 Duct Assembly 69B42215-1004 69B42215-42 0.5 Duct Assembly 69B42215-1042 69B42215-44 0.5 Duct Assembly 69B42215-1044 69B42215-47 0.5 Duct Assembly 69B42215-1047 69B42215-48 0.5 Duct Assembly 69B42215-1048 69B42215-54 0.5 Duct Assembly 69B42215-1054 69B42215-82 0.5 Duct Assembly 69B42215-1082 69B42217-2 0.5 Transition Assembly 69B42217-1102 69B42218-5 0.5 Duct Assembly 69B42218-1005 69B42218-6 0.5 Duct Assembly 69B42218-1006 69B42219-1 0.5 Duct Assembly 69B42219-1001 69B42219-19 0.5 Duct Assembly 69B42219-1019 69B42219-4 0.5 Duct Assembly 69B42219-1004 69B42219-7 0.5 Duct Assembly 69B42219-1007 69B42219-9 0.5 Duct Assembly 69B42219-1009 69B42220-6 0.5 Duct Assembly 69B42220-1106 69B42221-2 0.5 Duct Assembly 69B42221-1002 69B42221-3 0.5 Duct Assembly 69B42221-1003 69B42221-4 0.5 Duct Assembly 69B42221-1004 69B42471-8 0.5 Duct Assembly 69B42471-1008 69B42471-9 0.5 Duct Assembly 69B42471-1009 69B42472-1 0.5 Duct Assembly 69B42472-1001 69B42472-2 0.5 Duct Assembly 69B42472-1002 69B42472-5 0.5 Duct Assembly 69B42472-1005 69B42472-6 0.5 Duct Assembly 69B42472-1006 69B42473-3 0.5 Duct Assembly 69B42473-1003 69B42670-2 0.5 Duct Assembly 69B42670-1002 69B42809-1 0.5 Duct Assembly 69B42809-1001 69B42809-2 0.5 Duct Assembly 69B42809-1002 69B42809-3 0.5 Duct Assembly 69B42809-1003 69B42809-4 0.5 Duct Assembly 69B42809-1004 69B42820-1 0.5 Duct Assembly 69B42820-1001 69B42820-11 0.5 Duct Assembly 69B42820-1011 69B42820-12 0.5 Duct Assembly 69B42820-1012 69B42820-5 0.5 Duct Assembly 69B42820-1005 69B42820-6 0.5 Duct Assembly 69B42820-1006 Existing Part Number Insulation Thickness (inches) Name New Part Number ### Page 54 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 54 of 809 BOEING SERVICE BULLETIN 747-21A2421 4. Parts Removed and Not Replaced: None. 69B42820-7 0.5 Duct Assembly 69B42820-1007 69B42820-9 0.5 Duct Assembly 69B42820-1009 69B42822-1 0.5 Duct Assembly 69B42822-1001 69B42826-1 0.5 Duct Assembly 69B42826-1001 69B43024-10 0.5 Duct Assembly 69B43024-1010 69B43024-14 0.5 Duct Assembly 69B43024-1014 69B43024-25 0.5 Duct Assembly 69B43024-1025 69B43024-26 0.5 Duct Assembly 69B43024-1026 69B43024-30 0.5 Duct Assembly 69B43024-1030 69B43024-7 0.5 Duct Assembly 69B43024-1007 69B43033-1 0.5 Duct Assembly 69B43033-1001 69B43033-10 0.5 Duct Assembly 69B43033-1010 69B43033-13 0.5 Duct Assembly 69B43033-1013 69B43033-19 0.5 Duct Assembly 69B43033-1019 69B43033-3 0.5 Duct Assembly 69B43033-1003 69B43040-1 0.5 Duct Assembly 69B43040-1001 69B43040-2 0.5 Duct Assembly 69B43040-1002 69B43040-7 0.5 Duct Assembly 69B43040-1007 69B43040-8 0.5 Duct Assembly 69B43040-1008 69B43216-1 0.5 Duct Assembly 69B43216-1001 69B43450-1 0.5 Duct Assembly 69B43450-1001 69B43450-2 0.5 Duct Assembly 69B43450-1002 69B43495-3 0.5 Riser Crossover Assembly 69B43495-1003 69B43495-4 0.5 Riser Crossover Assembly 69B43495-1004 69B44112-1 0.5 Duct Assembly 69B44112-1001 69B44130-1 0.25 Duct Assembly 69B44130-1001 69B44137-1 0.5 Duct Assembly 69B44137-1001 69B44145-1 0.5 Duct Assembly 69B44145-1001 69B44145-3 0.5 Duct Assembly 69B44145-1003 69B44145-5 0.5 Duct Assembly 69B44145-1005 69B44145-7 0.5 Duct Assembly 69B44145-1007 69B47818-1 0.25 Duct Assembly 69B47818-1001 69B47948-1 0.5 Riser Crossover Assembly 69B47948-1001 69B47948-2 0.5 Riser Crossover Assembly 69B47948-1002 69B48565-1 0.5 Duct Assembly 69B48565-1001 Existing Part Number Insulation Thickness (inches) Name New Part Number ### Page 55 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 55 of 809 BOEING SERVICE BULLETIN 747-21A2421 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 operator’s spares supply. E. Special Tooling - Price and Availability Pressure Gauge capable of reading up to 20 in. of water. (For 747-100/-200/-300 airplanes only) 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. ### Page 56 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 56 of 809 BOEING SERVICE BULLETIN 747-21A2421 BLANK PAGE ### Page 57 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 57 of 809 BOEING SERVICE BULLETIN 747-21A2421 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 AMM 21-23-01 and 747-400 AMM 21-23-02 for information to repair damaged ducts. 2. Duct rework instructions can be found at the back of this service bulletin, in Appendix A. 3. Common access instructions to remove floor panels, sidewall panels, ceiling panels and cargo liner panels can be found in 747 AMM Chapter 25. 4. When possible the duct assemblies should be reworked while installed on the airplane. If necessary, remove the affected duct, rework it, then install the reworked duct back onto the airplane. 5. Some ducts are connected using a telescoping joint. These joints are connected using either BAC5412 Method 7 or BAC 5412 Method 8. If duct removal is required to rework, then refer to Appendix C (BAC5412 Method 7) and Appendix D (BAC5412 Method 8), when reconnecting these duct assemblies. 6. The Figures in the service bulletin may show ducts other than what is required for rework, for the specific airplane being modified. The operator will be shown, in the tables in Step 10. of these WORK INSTRUCTIONS, exactly which ducts require rework within each figure, for each airplane in their fleet. Only rework the ducts in each figure that apply to the airplane being modified. 7. If a duct is removed, all removed hardware such as sleeves, orifices (restrictors), and clamps, should be reused and replaced in the original configuration. In locations where the ducts are joined with flex sleeves and plastic tie straps, the plastic tie straps cannot be re-used. New tie straps should be used in these locations. Reference the tie strap selection guide in Appendix B., of this service bulletin to find the necessary tie strap part number for the size of the duct being installed. 8. If BMS 8-39 polyurethane foam insulation is found installed as a sleeving between the duct being reworked, replace these sleeves with new sleeves made from the BMS 8-300 polyimide foam insulation. Then completly wrap the sleeve with BMS 5-157 tape. 9. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for definition of the acronyms. 10. Obey all of the warnings and cautions given in the specified manual sections. 11. Unless shown differently, these dimensions and tolerances are used: — Linear dimensions are in inches ### Page 58 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 58 of 809 BOEING SERVICE BULLETIN 747-21A2421 — Torque limits to tighten nuts and bolts are given in 747 Structural Repair Manual, Chapter 51. 12. For approved fastener and process material substitutions, refer to 747 Structural Repair Manual, Chapter 51, Alternate fasteners are given in 747 Structural Repair Manual Chapter 51 and Boeing Drawing 65B88700 B. WORK INSTRUCTIONS Review the notes shown above before beginning the rework as specified in Step 1. of the WORK INSTRUCTIONS. 1. Determine the effectivity of the airplane being modified by this service bulletin. 2. Locate the airplane being modified in the tables shown in Step 10. of these WORK INSTRUCTIONS. Determine the applicable figures, steps and affected duct assemblies for the specific airplane being modified. The figures in the service bulletin may show additional ducts other than you are being requested to rework, for the specific airplane being modified. Only rework the ducts in the figure that apply to the airplane being modified. 3. Rework the affected assemblies on the applicable airplane. To determine the required thickness of the new BMS 8-300 insulation, refer the paragraph 2.C.3., Parts Modified and Reidentified. After reworking each assembly, partmark the new assembly with the part number shown in the figure. 4. THE FOLLOWING FUNCTIONAL TESTS IN STEP 4 ARE FOR 747-100/-200/-300 AIRPLANES ONLY. 747-400 AIRPLANES DO THE FUNCTIONAL TEST SHOWN IN STEP 7 OF THESE WORK INSTRUCTIONS. ON FREIGHTERS AIRPLANES, ONLY TEST THE SYSTEMS THAT ARE APPLICABLE TO YOUR AIRPLANE. On 747-100/-200/-300/SP/SR airplanes, after the ducts have been reworked and re-installed, perform the following functional tests to ensure correct installation and to verify the integrity of the complete conditioned air duct system. (Test Equipment Required: Pressure gauge capable of reading up to 20 in. of water (H20). Plenum Pressure and Leakage Test of the Air Distribution System a. The following airplanes do this step a.: RA002 - RA005, RA007, RA013, RA015, RA016, RA023, RA026, RA101 - RA103, RA106, RA112, RA162, RA253, RA303, RA401, RA402, RA501, RA522, RA631, RA901 - RA903, RA906 - RA908. Remove cover assembly from the floor box located just aft of STA 1220 and just outboard of RBL 33.99. Insert a 1/8 inch outside diameter tube into the hole and connect a pressure gauge or water manometer. The tube must be inserted perpendicular to the airstream or pointed slightly downstream when the pressure is measured, to avoid a ram air effect on the tube. b. All 747-100/-200/-300/SR/SP airplanes other than those listed in the above step a., and having a floor box installed just aft of STA 1140 and just outboard of RBL 11.33, do step b.(1). ### Page 59 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 59 of 809 BOEING SERVICE BULLETIN 747-21A2421 All 747-100/-200/-300/SR/SP airplanes other than those listed in the above step a., and which do not have the floor box installed just aft of STA 1140 and just outboard of RBL 11.33, do step b.(2). (1) Remove cover assembly from the floor box located just aft of STA 1140 and just outboard of RBL 11.33. Connect the pressure gauge or water manometer to the 3/8 inch outside diameter aluminum tube pressure tap near the top of the box. (2) Remove floor panel at location STA 1143, RBL 22, to get access to the conditioned air manifold. Drill a 0.125 inch diameter hole in the top center of the manifold duct at approximately STA 1143. Insert a 1/8 inch outside diameter tube into the hole and connect a pressure gauge or water manometer. The tube must be inserted perpendicular to the airstream or pointed slightly downstream when the pressure is measured, to avoid a ram air effect on the tube. After completion of the testing, clean the area around the hole with denatured or isopropyl alcohol and apply a minimum 2 inch square piece of 3M 425 Aluminum Tape (MIL-T-23397), over the hole, rubbing it down thouroghly to maximize contact and adhesion. c. All 747-100/-200/-300/SP/SR airplane do the following steps c. through g.: Operate the APU or the engines. If engines are used, adjust engine settings to approximately 70% N2. Supply air to all three packs and operate the packs in the manual mode. Using the pack selector buttons and the manual switch, toggle the turbine bypass valves for all three packs to approximately 25% off of the full cool (at 11:00 o’clock position). d. The gasper fan and supplemental recirculation fans shall be off. Zones 2, 3, and 4 recirculation fans shall be on. All pneumatic bleeds, other than A/C pack flow should be shut off. e. Verify by feel that there is air flow from all overhead air distribution nozzles. f. Determine the manifold pressure on the flight engineers panel and the plenum pressure. To find the acceptable plenum pressure, do the following: Airplanes RA002 - RA005, RA007, RA013, RA015, RA016, RA023, RA026, RA101 - RA103, RA106, RA112, RA162, RA253, RA303, RA401, RA402, RA501, RA522, RA631, RA901 - RA903, RA906 - RA908, should refer to "CHART 2 in Appendix F." If the noted pressure is equal to or exceeds the curve as indicated in the respective charts, end this test here. If the noted pressure does not equal or exceed the curve, as indicated in the respective chart, then continue to step g. All other airplanes should refer to "CHART 1 in Appendix E." If the noted pressure is equal to or exceeds the curve as indicated in the respective charts, end this test here. If the noted pressure does not equal or exceed the curve, as indicated in the respective chart, then continue to step g. g. For each 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. ### Page 60 August 14, 2003 Revision 2: December 19, 2006 747-21A2421 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 60 of 809 BOEING SERVICE BULLETIN 747-21A2421 (1) A concentrated leak is defined as a jet or a stream of air that can be felt on the palm of the hand three to four inches from the surface of the duct. Diffused leakage is allowed Passenger Gasper System Leak Test (where applicable) a. Provide electrical power. b. Open one gasper outlet in each cluster of gaspers (approximately 1/3 to 1/2 of all gaspers will be open). Gasper outlets are located above passenger seats. c. Apply power to the gasper system boost fan and recirculation fans (where applicable). d. For each 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. (1) A concentrated leak is defined as a jet or a stream of air that can be felt on the palm of the hand three to four inches from the surface of the duct. Diffused leakage is allowed e. Verify that air can be felt coming from the passenger air gasper nozzles. Equipment Cooling System Leak Test (where applicable) a. Provide electrical power. b. Ensure the Equipment Cooling System is operating and the airplane is in ground mode. c. Open BLOWER ALTERNATE – COOLING EQUIP circuit breaker on P15 panel. d. Verify that the following circuit breakers are closed: (1) BLOWER NORMAL – COOLING EQUIP (P15 panel) (2) FAN EQUIP COOLING – UPPER DECK (P15 panel) (3) VALVE DUMP UPPER DECK (P14 panel) (4) EQUIP COOL SMOKE DETECTOR CONTROL (P12 panel) (5) MISC CONTROL EQUIP COOLING VALVE (P6 panel) (6) EQUIPMENT COOLING CARGO VALVE CONTROL (P6 panel) e. Position EQUIPMENT COOLING BLOWER SELECTOR switch to NORM. f. Position VALVE CONTROL switch to NORM. g. For each 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. (1) A concentrated leak is defined as a jet or a stream of air that can be felt on the palm of the hand three to four inches from the surface of the duct. Diffused leakage is allowed 5. End of Functional Tests for 747-100/-200/-300 airplanes. 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