# Boeing Service Bulletin 747-53-2721: U.S. DOT/FAA - Boeing Service Bulletin - Rights: © The Boeing Company. Filed by the FAA in regulations.gov docket FAA-2013-0540; AD 2013-26-12 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. - Document: [Boeing Service Bulletin 747-53-2721](https://openairdocs.org/service-documents/boeing/sb-747-53-2721.md) - Title as filed: U.S. DOT/FAA - Boeing Service Bulletin - Pages: 140 - PDF: https://openairdocs.org/files/sha256/fe/c7/fec78260e69d1977ed63fd2300a37e2a0f0ad3f4c0ae06ac2fd05c85089be3de - Page: https://openairdocs.org/service-documents/boeing/sb-747-53-2721/file/fec78260e69d ## Text Some pages are OCR from a scan. OCR can misread letters and numbers. Each page's text from the PDF; open the PDF at a page with #page=N. ### Page 1 Commercial Airplanes 747 Service Bulletin Number: 747-53-2721 Original Issue: May 28, 2009 Revision 3: June 25, 2013 ATA System: 5331 SUBJECT: FUSELAGE - Skin - Install Rub Strips at Vertical Fin Seal to Fuselage Interface Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15 CFR 300-774). An export license may be required before it is used for development, production or use by foreign persons from specific countries. The controller of this data has the individual responsibility to abide by all export laws. 9E991ECCN: BOEING PROPRIETARY, CONFIDENTIAL AND/OR TRADE SECRET Copyright © 2009 Boeing. Unpublished Work. All Rights Reserved. Treatment of this document and its content is governed by contract with Boeing. Rights to use this document are licensed on a per aircraft basis and such rights may not be transferable. For more information, contact The Boeing Company. Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, Dreamliner, BBJ, DC-8, DC-9, DC-10, KC-10, KC-46, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8, Poseidon and Boeing liveries are all trademarks owned by The Boeing Company; and no trademark license is granted in connection with this document unless provided in writing by Boeing. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 1 of 140 4.0 ### Page 2 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 2 of 140 BOEING SERVICE BULLETIN 747-53-2721 BLANK PAGE ### Page 3 Table of Contents Revision Transmittal Sheet ............................................ 5 Summary ...................................................... 7 1. PLANNING INFORMATION ........................................ 1 1 A. Effectivity ............................................... 1 1 1. Airplanes ............................................ 1 1 2. Spares Affected ........................................ 2 0 B. Concurrent Requirements ...................................... 2 0 C. Reason ................................................ 2 0 D. Description .............................................. 2 2 E. Compliance .............................................. 2 3 F. Approval ............................................... 2 9 G. Manpower .............................................. 2 9 H. Weight and Balance Changes .................................... 3 1 I. Electrical Load Data ......................................... 3 1 J. References .............................................. 3 1 1. Existing Data: ......................................... 3 1 2. Data Supplied with this Service Bulletin: ........................... 3 2 3. Installation Drawings Used in the Preparation of this Service Bulletin: ........... 3 3 K. Publications Affected ........................................ 3 3 L. Interchangeability and Intermixability of Parts ........................... 3 3 M. Software Accomplishment Summary ................................ 3 3 2. MATERIAL INFORMATION ........................................ 3 5 A. Material - Price and Availability ................................... 3 5 B. Industry Support Information .................................... 3 6 C. Parts Necessary for Each Airplane ................................. 3 6 1. Kits/Parts ............................................ 3 6 2. Parts and Materials Supplied by the Operator ........................ 4 8 3. Parts Modified and Reidentified ................................ 4 8 4. Parts Removed and Not Replaced .............................. 4 8 D. Parts Necessary to Change Spares ................................. 4 9 E. Special Tooling - Price and Availability ............................... 4 9 F. Special Tooling Necessary to do this Service Bulletin ....................... 4 9 3. ACCOMPLISHMENT INSTRUCTIONS .................................. 5 1 A. GENERAL INFORMATION ..................................... 5 1 B. WORK INSTRUCTIONS ....................................... 5 3 FIGURE 1: PREPARE FOR THE FORWARD RUB STRIP INSTALLATION [Group 1] ......... 6 5 FIGURE 2: PREPARE FOR THE AFT RUB STRIP INSTALLATION ................... 6 8 FIGURE 3: FORWARD RUB STRIP INSTALLATION [Group 1] ..................... 7 1 FIGURE 4: AFT RUB STRIP INSTALLATION ............................... 7 9 FIGURE 5: DELETED ............................................ 8 6 FIGURE 6: DELETED ............................................ 8 7 FIGURE 7: PREPARE FOR THE FORWARD RUB STRIP INSTALLATION [Group 2] ......... 8 8 FIGURE 8: FORWARD RUB STRIP INSTALLATION [Group 2] ..................... 9 2 FIGURE 9: PREPARE FOR THE FORWARD RUB STRIP INSTALLATION [Group 3] ........ 1 0 1 FIGURE 10: FORWARD RUB STRIP INSTALLATION [Group 3] .................... 1 0 6 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 3 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 4 FIGURE 11: ZONE 1 - FULL-LENGTH REPAIR - LEFT SIDE - POST REPAIR INSPECTION [Group 1] . 117 FIGURE 12: ZONE 1 - FULL-LENGTH REPAIR - RIGHT SIDE - POST REPAIR INSPECTION [Group 1] ................................................. 1 2 3 FIGURE 13: ZONE 1 - FULL-LENGTH REPAIR - LEFT SIDE - POST REPAIR INSPECTION [Group 2] . 129 FIGURE 14: ZONE 1 - FULL-LENGTH REPAIR - RIGHT SIDE - POST REPAIR INSPECTION [Group 2] ................................................. 1 3 5 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 4 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 5 Commercial Airplanes 747 Service Bulletin Revision Transmittal SheetNumber: 747-53-2721Original Issue: May 28, 2009 Revision 3: June 25, 2013 ATA System: 5331 SUBJECT: FUSELAGE - Skin - Install Rub Strips at Vertical Fin Seal to Fuselage Interface This revision includes all pages of the service bulletin. COMPLIANCE INFORMATION RELATED TO THIS REVISION No more work is necessary on the airplane(s) changed or inspected in accordance with the original issue, Revision 1 or Revision 2 of this service bulletin. Federal Aviation Administration (FAA) Airworthiness Directive AD 2009-14-02, is related to this service bulletin. REASON FOR REVISION This revision is sent to clarify the post modification and post repair inspections requirements and to transfer post repair inspection instructions from the Structural Repair Manual (SRM) and Repair Assessment Guidelines (RAG) to this service bulletin for airplanes that have the zone 1 full length repair installed. These sections were changed: 1. Summary, Background: A fleet team digest reference and a planning table is added. 2. Summary, Action: A post repair inspection is added. 3. Paragraph 1.C., Reason: Clarify post modification and post repair inspections requirements and transferred post repair inspection instructions from the Structural Repair Manual (SRM) and Repair Assessment Guidelines (RAG) for airplanes that have the zone 1 full length repair installed. 4. Paragraph 1.D., Description: A post repair inspection is added. 5. Paragraph 1.E., Compliance: Repair Assessment Guidelines (RAG) and a Structural Repair Manual (SRM) reference is added. Table 2 title is changed. Table 2 is updated to include new Zone 1 post repair inspections and the compliance for RAG and SRM inspections has been removed from Table 2 and Table 3. 6. Paragraph 1.G., Manpower: Manpower times for Zone 1 post repair inspections is added. 7. Paragraph 1.K., Publications Affected, Damage Tolerance Based Structural Inspections: New statements added. 8. Paragraph 1.M., Software Accomplishment Summary: Software accomplishment summary section is added. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 5 of 140 ### Page 6 9. Paragraph 2.A., Material - Price and Availability: Repair Kit zone names have been changed. 10. Paragraph 2.C., Parts Necessary For Each Airplane: Corrected the zone names for kit numbers. 11. Paragraph 3.A., General Information: The notes section is updated. 12. Paragraph 3.B., Work Instructions: Are updated to include new Zone 1 post repair inspections. 13. FIGURE 11, FIGURE 12, FIGURE 13 and FIGURE 14: Zone 1 post repair inspections are added. The data given in Information Notice 747-53-2721 IN 02 is included in this revision. The data given in Information Notice 747-53-2721 IN 03 is included in this revision. Vertical lines are put on the left edge of each page, except in Paragraph 1.A., Effectivity and format changes, to show the location of all content changes. Pages with no vertical lines have no important changes. REVISION HISTORY May 28, 2009Original Issue: June 24, 2010Revision 1: March 17, 2011Revision 2: June 25, 2013Revision 3: Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 6 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 7 Commercial Airplanes 747 Service Bulletin SummaryNumber: 747-53-2721Original Issue: May 28, 2009 Revision 3: June 25, 2013 ATA System: 5331 SUBJECT: FUSELAGE - Skin - Install Rub Strips at Vertical Fin Seal to Fuselage Interface CONCURRENT REQUIREMENTS The service bulletin listed below must be done before or at the same time as this service bulletin: DescriptionService BulletinCompany Inspects and repairs skin damage to the fuselage at the vertical stabilizer seal interface. 747-53A2478 Revision 1, Revision 2 or Revi- sion 3 Boeing BACKGROUND This service bulletin gives instructions to install corrosion resistant steel (CRES) rub strips on the skin on the aft fuselage at the vertical fin blade seal to fuselage interface. Installation of these rub strips will prevent skin wear damage which results in thinning of the skin and could lead to cracking. Undetected cracking in the pressurized Section 46 could reach sufficient length to cause in-flight depressurization of the airplane. Operators have reported skin wear damage beyond allowable limits at the vertical stabilizer blade seal to fuselage interface in Section 46 and Section 48. Service Bulletin 747-53A2478 was issued to provide repeat inspection and repair instructions for this skin wear. Accomplishment of the rub strip installation will protect the skin in the affected area from wear damage at the vertical fin blade seal interface, and terminate the repeat inspection requirements of Service Bulletin 747-53A2478. Repeat inspection requirements for installed rub strips is given in this service bulletin. If the rub strip installation given in this service bulletin is not accomplished, operators will be required to continue to do inspections in accordance with Service Bulletin 747-53A2478 and AD 2009-14-02. As a part of a service bulletin validation program, this change was completed on airplane RM803 by Service Bulletin 747-53-2721 Original Issue before the release of Revision 1 of this service bulletin. The change completed on airplane RM803 by Service Bulletin 747-53-2721 Original Issue is equivalent to Revision 1 of this service bulletin. Airplane RM803 has the configuration of a Group 1 airplane. Boeing Service Related Problem (SRP) 747-SRP-53-0296 is related to this service bulletin. Boeing Fleet Team Digest (FTD) 747 FTD 53-06007 is related to this service bulletin. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 7 of 140 ### Page 8 This table is provided to operators for planning purposes only. Refer to the applicable sections for more information. ReferenceAffectedPlanning Data Paragraph 1.A.2., Spares AffectedNoSpares Affected Paragraph 1.E., Compliance and Paragraph 1.F., Approval YesAD Related Paragraph 1.H., Weight and Balance ChangesYesWeight and Balance Change Paragraph 1.I., Electrical Load DataNoElectrical Load Changed Paragraph 1.K., Publications AffectedNoPublications Affected Paragraph 1.K., Publications AffectedNoAirplane Flight Operations Affected (Flight Crew Operations Manual and/or FAA Approved Air- plane Flight Manual) Paragraph 2.C.1., Kits/PartsYesKits/Parts Required Paragraph 2.C.2., Parts and Materials Supplied by the Operator YesOperator Supplied Parts/Material Paragraph 2.F., Special Tooling Necessary to do this Service Bulletin NoSpecial Tooling Required ACTION (PRR 85901-83S) This service bulletin installs new CRES rub strips to the skin at the vertical stabilizer fin blade seal and fuselage interface. For the actions in this service bulletin, the areas where rub strips are installed are divided into the following zones: – Zone 1: STA 2280 to STA 2360 (Section 46) (STA 2072 to STA 2360 on Group 2 airplanes) – Zone 2: STA 2360 to STA 2397 (Section 48) – Zone 3: STA 2397 to STA 2417 (Section 48) – Zone 4: STA 2517 to STA 2557 (Section 48) – Zone 5: STA 2557 to STA 2598 (Section 48) – Zone 6: STA 2598 to STA 2638 (Section 48) Do post repair and post modification inspections in accordance with Paragraph 1.E., Compliance or if local repairs were installed, do additional post modification and post repair inspections of the repaired areas in accordance with the applicable Repair Assessment Guidelines (RAG) and/or Structural Repair Manual (SRM). EFFECTIVITY 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SP and 747SR series airplanes. Refer to Paragraph 1.A.1., Airplanes for the list of affected airplanes. COMPLIANCE Federal Aviation Administration (FAA) Airworthiness Directive AD 2009-14-02 is related to this service bulletin. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 8 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 9 Refer to Paragraph 1.E., Compliance. INDUSTRY SUPPORT INFORMATION Boeing warranty remedies are not available for the configuration changes, inspection, and/or repair procedures given in this service bulletin. MANPOWER Work Package 1 - Forward Rub Strip Installation: Elapsed HoursTotal Task HoursAirplanes 18.7538.00747 Work Package 2 - Aft Rub Strip Installation: Elapsed HoursTotal Task HoursAirplanes 12.7533.25747 Zone 1 Post Repair Inspection Elapsed HoursTotal Task HoursAirplanes 18.0036.00Group 1 20.0053.00Group 2 Refer to Paragraph 1.G., Manpower. MATERIAL INFORMATION Operator Supplied Parts/Materials. Refer to Paragraph 2.A., Material - Price and Availability Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 9 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 10 (OCR) BOEING SERVICE BULLETIN 747-53-2721 INSTALL RUB STRIPS AT VERTICAL FIN SEAL TO FUSELAGE INTERFACE STA 2628 STA 2521 STA 2360 STA 12413 STA I 2280 BULKHEAD AFT PRESSURE GROUP 1 AIRPLANE SHOWN GROUP 2 - 3 SIMILAR 1662857 Original Issue: May 28, 2009 Revision 3: June 25, 2013 PROPRIETARY - Copyright © Unpublished Export Controlled ECCN: 9E991 - BOEING 747-53-2721 Work - See page 1 for details. 10 of 140 ### Page 11 Commercial Airplanes 747 Service Bulletin Number: 747-53-2721 Original Issue: May 28, 2009 Revision 3: June 25, 2013 ATA System: 5331 SUBJECT: FUSELAGE - Skin - Install Rub Strips at Vertical Fin Seal to Fuselage Interface 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. On airplane line number 1385, rub strips were installed in production by Rapid Revision RR47040-92. This service bulletin is for the airplanes shown below. Refer to PRR 85901-83S for data about this change. DESCRIPTIONCONFIGURATIONGROUP 747 series airplanes line number 1-1384 and 1386-1419, except 747SP and 747 LCF airplanes. -1 All 747SP airplanes.-2 747 LCF airplanes.-3 Airplane Models: 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SP, 747SR GroupVariable Number 1RA001 - RA034 1RA101 - RA115 1RA161 - RA164 1RA201 - RA203 1RA216 - RA217 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 11 of 140 ### Page 12 GroupVariable Number 1RA245 - RA246 1RA251 - RA266 1RA301 - RA318 1RA351 - RA360 1RA369 - RA373 1RA401 - RA418 1RA501 - RA502 1RA521 - RA528 1RA532 - RA548 1RA551 - RA552 1RA559 - RA561 1RA581 - RA582 1RA585 1RA601 - RA602 1RA631 - RA635 1RA651 - RA652 1RA671 - RA677 1RA701 - RA702 1RA721 - RA731 1RA741 - RA745 1RA749 - RA750 1RA761 - RA762 1RA781 - RA784 1RA901 - RA916 1RB001 - RB016 1RB041 - RB044 1RB071 - RB075 1RB101 - RB102 1RB411 - RB413 1RB421 1RB601 - RB607 1RB681 - RB697 1RB711 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 12 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 13 GroupVariable Number 1RB721 - RB723 1RB741 - RB748 1RD001 - RD004 1RD021 - RD022 1RD041 - RD059 1RD071 - RD072 1RD081 - RD083 1RD091 - RD092 1RD101 - RD104 1RD121 - RD127 1RD131 - RD144 1RD166 - RD167 1RD171 - RD172 1RD181 - RD183 1RD201 - RD204 1RD221 - RD227 1RD231 - RD235 1RD241 - RD243 1RD251 - RD262 1RD271 - RD272 1RD291 - RD292 1RD301 - RD302 1RD311 1RD351 - RD358 1RD361 - RD366 1RD381 - RD383 1RD411 - RD414 1RD421 - RD426 1RD431 - RD435 1RD441 - RD442 1RD451 - RD456 1RD461 1RD471 - RD475 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 13 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 14 GroupVariable Number 1RD513 - RD519 1RD531 - RD533 1RD551 1RD561 1RD571 1RD581 - RD583 1RD591 - RD593 1RD601 - RD607 1RD621 - RD623 1RD641 - RD649 1RD651 - RD659 1RD661 1RD671 1RD681 - RD682 1RD691 - RD692 1RD701 - RD702 1RD721 - RD722 1RD741 - RD742 1RD751 - RD755 1RD761 1RD771 - RD775 1RD781 - RD783 1RD791 - RD792 1RE001 1RF001 - RF006 2RG001 - RG009 2RG091 2RG095 2RG101 - RG104 2RG121 - RG126 2RG141 - RG142 2RG161 - RG164 2RG171 - RG174 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 14 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 15 GroupVariable Number 2RG191 - RG193 2RG211 - RG213 2RG221 - RG222 2RH101 - RH102 2RH111 - RH112 2RH121 - RH122 1RJ131 - RJ133 1RJ151 - RJ152 1RJ301 - RJ303 1RJ321 - RJ322 1RJ331 - RJ333 1RL401 - RL403 1RL411 - RL436 1RL451 - RL456 1RL461 - RL462 1RL471 - RL480 1RL491 - RL492 1RL501 - RL502 1RL511 - RL516 1RL521 - RL522 1RL531 - RL534 1RL551 1RL561 - RL568 1RL571 - RL572 1RL576 - RL577 1RL579 1RL581 - RL586 1RL651 - RL655 1RL671 - RL675 1RL681 - RL684 1RL751 - RL752 1RM001 - RM007 1RM010 - RM013 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 15 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 16 GroupVariable Number 1RM021 - RM024 1RM026 - RM030 1RM036 - RM045 1RM051 - RM053 1RM071 1RM081 - RM084 1RM091 1RM096 - RM097 1RM116 - RM117 1RM126 - RM132 1RM136 - RM147 1RM156 - RM158 1RM166 - RM177 1RM191 - RM192 1RM231 - RM233 1RM241 - RM246 1RM261 - RM264 1RM316 - RM318 1RM331 - RM333 1RM341 1RM351 - RM355 1RM366 - RM367 1RM401 - RM403 1RM426 1RM431 1RM441 - RM443 1RM445 1RM801 - RM803 1RM811 - RM813 1RM851 - RM859 1RM861 - RM863 1RM871 - RM899 1RM901 - RM906 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 16 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 17 GroupVariable Number 1RM911 1RR001 - RR005 1RR021 - RR025 1RR031 1RR201 - RR206 1RR221 - RR226 1RR261 - RR267 1RR301 - RR310 1RR331 - RR332 1RR336 1RR341 - RR345 1RR361 - RR362 1RR421 - RR422 1RR431 - RR432 1RR441 - RR442 1RR451 1RR501 - RR504 1RR521 - RR522 1RR526 1RR531 1RR551 - RR556 1RR561 1RR566 1RR701 1RR721 - RR724 1RR746 - RR748 1RR851 - RR856 1RR861 - RR862 1RR951 - RR952 1RS001 - RS002 1RS201 1RS211 - RS212 1RS221 - RS222 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 17 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 18 GroupVariable Number 1RS231 - RS241 1RS251 - RS259 1RS263 1RS265 - RS268 1RS271 - RS276 1RS291 - RS292 1RS301 - RS306 1RS311 - RS320 1RS331 - RS333 1RS341 - RS342 1RS699 1RS701 - RS703 1RS711 - RS713 1RS721 - RS722 1RS731 - RS732 1RS741 - RS743 1RS751 - RS752 1RS761 - RS762 1RS771 1RS781 - RS782 1RS786 1RT001 - RT014 1RT021 - RT022 1RT031 - RT035 1RT041 - RT047 1RT061 1RT071 - RT075 1RT101 - RT103 1RT121 1RT131 - RT137 1RT151 - RT152 1RT161 - RT168 1RT401 - RT412 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 18 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 19 GroupVariable Number 1RT431 - RT447 1RT451 - RT469 1RT471 - RT499 1RT501 - RT535 1RT551 - RT568 1RT571 - RT591 1RT601 - RT630 3RT631 - RT632 1RT633 - RT657 1RT671 - RT673 1RT681 - RT682 1RT691 - RT699 1RT701 - RT704 1RT711 - RT717 1RT741 - RT742 3RT743 1RT744 - RT757 1RT776 - RT777 1RT781 - RT784 1RT801 - RT803 1RT811 - RT814 1RT831 - RT837 1RT861 - RT864 3RT876 1RT877 - RT880 1RT931 - RT932 1RT945 - RT949 1RT951 - RT955 1RT966 - RT967 1RU001 - RU006 1RU016 - RU017 1RU031 - RU032 1RU051 - RU052 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 19 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 20 GroupVariable Number 1RU059 - RU062 1RU081 - RU083 1RU101 - RU102 1RU121 - RU132 1RU801 - RU809 1RU831 - RU841 2. Spares Affected None. B. Concurrent Requirements The service bulletin listed below must be done before or at the same time as this service bulletin: DescriptionService BulletinCompany Inspects and repairs skin damage to the fuselage at the vertical stabilizer seal interface. 747-53A2478 Revision 1, Revision 2 or Revi- sion 3 Boeing C. Reason This service bulletin gives instructions to install corrosion resistant steel (CRES) rub strips on the skin on the aft fuselage at the vertical fin blade seal to fuselage interface. Installation of these rub strips will prevent skin wear damage which results in thinning of the skin and could lead to cracking. Undetected cracking in the pressurized Section 46 could reach sufficient length to cause in-flight depressurization of the airplane. Operators have reported skin wear damage beyond allowable limits at the vertical stabilizer blade seal to fuselage interface in Section 46 and Section 48. Service Bulletin 747-53A2478 was issued to provide repeat inspection and repair instructions for this skin wear. Accomplishment of the rub strip installation will protect the skin in the affected area from wear damage at the vertical fin blade seal interface, and terminate the repeat inspection requirements of Service Bulletin 747-53A2478. Repeat inspection requirements for installed rub strips is given in this service bulletin. If the rub strip installation given in this service bulletin is not accomplished, operators will be required to continue to do inspections in accordance with Service Bulletin 747-53A2478 and AD 2009-14-02. As a part of a service bulletin validation program, this change was completed on airplane RM803 by Service Bulletin 747-53-2721 Original Issue before the release of Revision 1 of this service bulletin. The change completed on airplane RM803 by Service Bulletin 747-53-2721 Original Issue is equivalent to Revision 1 of this service bulletin. Airplane RM803 has the configuration of a Group 1 airplane. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 20 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 21 Revision 1 is sent to update the tables in Paragraph 1.E., Compliance. Compliance Tables 2 and 3 have been combined into new Table 2 in this revision. As shown in new Table 2, post modification inspections of the skin under installed rub strips in Section 46 where a repair is installed should be done in accordance with the 747 Repair Assessment Guidelines. If no repair is installed but the skin has been blended within the limits given in the applicable Structural Repair manual, inspections of the skin under the rub strip is only necessary in Zone 1 (STA 2280 to STA 2360). A new Table 3 has been added to Paragraph 1.E., Compliance. Table 3 gives post modification instructions for rub strips that were installed prior to the release of this service bulletin which were approved by Boeing in accordance with an FAA 8110-3 form or an FAA 8100-9 form. Kits for repairs that cover the full-length of the affected skin panels have been added. As part of the repair definitions, the affected skin areas have been divided into six Zones. Zones 1, 2, and 3 are applicable to the three skin panels affected by the forward rub strip installation area. Zones 4, 5, and 6 are applicable to the three skin panels affected by the aft rub strip installation area. Repair kits for Zones 1 through 5 are listed in Paragraph 2.A., Material - Price and Availability and Paragraph 2.C.1., Kits/Parts. Drawings 146U0001 and 148U0027, which give details of the Zone 1 through Zone 5 repairs and are sent with this revision, are listed in Paragraph 1.J.2., Data supplied with this Service Bulletin. The steps in Paragraph 3.B., Work Instructions have been changed to show that the skin wear and blend out limits are in accordance with the applicable Structural Repair Manual, rather than the 0.007 inch limit included in the initial release of this service bulletin. Paragraph 3.B., Work Instructions, PART 4 has been added to give instructions for repairs that may be necessary in the affected rub strip areas. Preparation Figures 1 and 2 have been changed to recommend that an open-hole High Frequency Eddy Current (HFEC) inspection be done at the affected fastener locations prior to rub strip installation. The Summary illustration and the locators in Figures 2 and 4 have been changed to more clearly show the applicable Body Station locations in the aft rub strip installation area. The steps in Paragraph 3.B., Work Instructions, Work Package 2 for removal and reinstallation of the vertical fin for access to the rub strip installation area have been removed. In addition, the data in Figures 5 and 6, for removal and reinstallation of stringer splices for access to the aft rub strip installation area, has been removed. Boeing has determined that removal of the vertical fin for access to the rub strip installation area is not necessary. References to the service bulletin validation that was completed in accordance with the initial release of this service bulletin have been added. The data given in Information Notice 747-53-2721 IN 01 is included in this revision. IN 01 was issued to advise that, it was not necessary to remove the vertical fin for access to the aft rub strip installation area. IN 01 also advised that in View A of Figure 4, the location identified as "STA 2517.25" should instead be "STA 2537.25". Revision 2 is sent to include rub strip installation instructions for 747SP and 747 Large Cargo Freighter (LCF) airplanes. Revision 3 is sent to clarify the post modification and post repair inspections requirements and to transfer post repair inspection instructions from the Structural Repair Manual (SRM) and Repair Assessment Guidelines (RAG) to this service bulletin for airplanes that have the zone 1 full length repair installed. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 21 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 22 Boeing Service Related Problem (SRP) 747-SRP-53-0296 is related to this service bulletin. D. Description This service bulletin installs new CRES rub strips to the skin at the vertical stabilizer fin blade seal and fuselage interface. For the actions in this service bulletin, the areas where rub strips are installed are divided into the following zones: – Zone 1: STA 2280 to STA 2360 (Section 46) (STA 2072 to STA 2360 on Group 2 airplanes) – Zone 2: STA 2360 to STA 2397 (Section 48) – Zone 3: STA 2397 to STA 2417 (Section 48) – Zone 4: STA 2517 to STA 2557 (Section 48) – Zone 5: STA 2557 to STA 2598 (Section 48) – Zone 6: STA 2598 to STA 2638 (Section 48) Do post repair and post modification inspections in accordance with Paragraph 1.E., Compliance or if local repairs were installed, do additional post modification and post repair inspections of the repaired areas in accordance with the applicable Repair Assessment Guidelines (RAG) and/or Structural Repair Manual (SRM). Revision 1 - No more work is necessary on airplanes changed in accordance with the original issue of this service bulletin. However, post repair and post modification inspections have been added. Revision 2 - No more work is necessary on the airplanes changed in accordance with the original issue or Revision 1 of this service bulletin. Do post repair or post modification inspections in accordance with Paragraph 1.E., Compliance. Revision 3 - No more work is necessary on the airplane(s) changed or inspected in accordance with the original issue, Revision 1 or Revision 2 of this service bulletin. The work in this service bulletin is done in the maintenance zone(s) given below. Group 1: Affected Maintenance Zones ZoneModel 273, 274, 311, 312, 313, 314, 315, 316747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR Group 2: Affected Maintenance Zones ZoneModel 273, 274, 311, 312, 313, 314, 315, 316747SP Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 22 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 23 Group 3: Affected Maintenance Zones ZoneModel 273, 274, 311, 312, 313, 314, 315, 316747-400 E. Compliance Federal Aviation Administration (FAA) Airworthiness Directive AD 2009-14-02 is related to this service bulletin. Rub Strip Installation 1. No compliance time is given for the rub strip installations given in Paragraph 3.B., Work Instructions, Part 1. Airplanes that have Rub Strips Installed in accordance with this Service Bulletin, or Approved by Boeing in Accordance With an FAA 8110-3 Form or an FAA 8100-9 Form Prior to the Original Issue of this Service Bulletin 1. When all rub strips have been installed, inspections in accordance with Service Bulletin 747-53A2478 are no longer necessary. 2. For airplanes which have had rub strips installed, Boeing recommends the following: a. On any airplane with rub strips installed in accordance with this service bulletin, or as approved by Boeing in accordance with an FAA 8110-3 Form or an FAA 8100-9 Form prior to the original issue of this service bulletin, do inspections of the rub strips and blade seals in accordance with Table 1. b. On any airplane with rub strips or repairs installed in accordance with this service bulletin, do inspections of the fuselage skin in accordance with Table 2. c. On any airplane with rub strips installed as approved by Boeing in accordance with an FAA 8110-3 Form or an FAA 8100-9 Form prior to the original issue of this service bulletin, do inspections of the fuselage skin in accordance with Table 3. 3. If local repairs were installed, additional post modification and post repair inspections of the repaired areas are provided in the applicable Repair Assessment Guidelines (RAG) and/or Structural Repair Manual (SRM). Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 23 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 24 Table 1: Post Modification or Post Repair Inspection of Installed Rub Strips and Blade Seals Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Earlier ) ActionCondition 10,000 flight-cycles or 36,000 flight- hours, whichever occurs earlier. Within 36,000 flight-hours after rub strip installa- tion. Within 10,000 flight-cycles af- ter rub strip in- stallation. Do an external detailed in- spection of the rub strips and blade seals for dam- age or wear in accordance with Paragraph 3.B., Work Instructions, Part 2, Work Package 3. Rub Strips installed for- ward of STA 2417 in accor- dance with this service bulletin, or as approved by Boeing in accordance with an FAA 8110-3 Form or an FAA 8100-9 Form prior to the original issue of this service bulletin. 10,000 flight-cycles or 36,000 flight- hours, whichever occurs earlier. Within 36,000 flight-hours after rub strip installa- tion. Within 10,000 flight-cycles af- ter rub strip in- stallation. Do an external detailed in- spection of the rub strips and blade seals for dam- age or wear in accordance with Paragraph 3.B., Work Instructions, Part 2, Work Package 4. Rub Strips installed aft of STA 2517 in accordance with this service bulletin, or as approved by Boeing in accordance with an FAA 8110-3 Form or an FAA 8100-9 Form prior to the original issue of this ser- vice bulletin. -Before further flight.Install new rub strip(s) in accordance with Paragraph 3.B., Work Instructions, Part 1. Rub strips that have wear greater than 0.008 inch deep, or that have loss of adhesion to the fuselage skin, or that are found to be buckled. -Before further flight.Replace any torn or gouged blade seals or any loose or missing fasteners. Blade seals that are torn or gouged, or loose or miss- ing fasteners. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 24 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 25 Table 2 : Post Modification or Post Repair Inspection of the Fuselage Skin in Areas With Rub Strips In- stalled in Accordance With this Service Bulletin Repeat Interval (Not to Exceed) Compliance TimeActionCondition 3,000 flight cycles.Within 15,000 total flight cycles after the installation of the repair. Do a post repair internal de- tailed inspection of the Zone 1 Full-Length Repair for any crack in accordance with Paragraph 3.B., Work Instructions, Part 5. (Zone 1 work only). And Zone 1 with a rub strip and a Full-Length Repair installed in accordance with Paragraph 3.B., Work Instructions, Part 4. 1,500 flight cycles.Do a post repair external de- tailed inspection of the Zone 1 Full-Length Repair for any crack in accordance with Paragraph 3.B., Work Instructions, Part 5. (Zone 1 work only). And 1,500 flight cycles.Do a post repair external Low Frequency Eddy Current (LFEC) inspection of the Zone 1 Full- Length Repair for any crack in accordance with Paragraph 3.B., Work Instructions, Part 5. (Zone 1 work only). Or 6,000 flight cycles.Do a post repair internal surface High Frequency Eddy Current (HFEC) inspection of the Zone 1 Full-Length Repair for any crack in accordance with Para- graph 3.B., Work Instructions, Part 5. (Zone 1 work only). 6,000 flight cycles.Before 20,000 total flight cycles, or within 6,000 flight-cycles after rub strip installation, whichever is later. Remove the rub strips. Do exter- nal detailed and surface HFEC inspections of the fuselage skin that was under the rub strips or tapered fillers, but not under the Local Repair, for cracks in accor- dance with Paragraph 3.B., Work Instructions, Part 3, Work Package 5 (Zone 1 work only). Zone 1 with a rub strip and any Local Repair installed in accor- dance with Paragraph 3.B., Work Instructions, Part 4. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 25 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 26 Table 2 : Post Modification or Post Repair Inspection of the Fuselage Skin in Areas With Rub Strips In- stalled in Accordance With this Service Bulletin Repeat Interval (Not to Exceed) Compliance TimeActionCondition 6,000 flight cycles.Before 20,000 total flight cycles, or within 6,000 flight-cycles after rub strip installation, whichever is later. Remove the rub strips and do external detailed and surface HFEC inspections of the fuse- lage skin that was under the rub strips for cracks in accordance with Paragraph 3.B., Work In- structions, Part 3, Work Pack- age 5 (Zone 1 work only). Zone 1 with rub strips installed with no Full-Length or Local Repairs, but with skin blends that do not exceed the limits given in the Structural Repair Manual. -At or before 35,000 to- tal flight-cycles. (a) Contact The Boeing Company for additional modification and/or inspection instructions and do the modification and/or inspection as applicable. Zone 1 with rub strips installed with no Full-Length or Local Repairs, and no skin blends. -Before further flight.Install a repair in accordance with Paragraph 3.B., Work In- structions, Part 4. If a Local Re- pair is installed, install new rub strips in accordance with Para- graph 3.B., Work Instructions, Part 1. Any crack found in Zone 1 after rub strip removal. -Before further flight.Install new rub strips in accor- dance with Paragraph 3.B., Work Instructions, Part 1. No crack found in Zone 1 after rub strip removal. -Before further flight.Contact The Boeing Company for repair instructions and do the repair. Any crack found in a Zone 1 Full-Length Repair inspection in accordance with Paragraph 3.B., Work Instructions, Part 5. -At or before 35,000 to- tal flight-cycles. (a) Contact The Boeing Company for additional modification and/or inspection instructions and do the modification and/or inspection as applicable. Any affected Zone 2 through Zone 6 with rub strips installed, with or without repairs, and with no skin blends or with skin blends that do not exceed the limits given in the Structural Repair Manual. (a) Limit of Validity. Refer to Boeing Service Letter 747-SL-53-088 or Fleet Team Digest 747-FTD-51-07001. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 26 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 27 Table 3: Post Modification or Post Repair Inspections of the Fuselage Skin in Areas With Rub Strips In- stalled Prior to the Original Issue of This Service Bulletin Repeat Interval (Not to Exceed) (b) Compliance Time (Whichever Occurs Later ) (b) Action (b)Condition 6,000 flight cycles.Within 6,000 flight-cycles af- ter rub strip in- stallation. Before 20,000 total flight cy- cles. Remove the rub strips. Do external detailed and sur- face HFEC inspections of the fuselage skin that was under the rub strips, but not under the repair, for cracks in accordance with Paragraph 3.B., Work In- structions, Part 3, Work Package 5 (Zone 1 work only). Zone 1 with CRES rub strips installed prior to the original issue of this ser- vice bulletin, approved by Boeing in accordance with an FAA 8110-3 form or an FAA 8100-9 form, with any internal or external reinforc- ing structural repair in- stalled. -1,200 flight-cy- cles after the date on Revi- sion 1 of this service bulletin. At or before 35,000 total flight-cycles. (a) Contact The Boeing Com- pany for additional modifi- cation and/or inspection instructions and do the modification and/or inspec- tion as applicable. Zone 2 through Zone 6 with CRES rub strips in- stalled prior to the original issue of this service bul- letin, approved by Boeing in accordance with an FAA 8110-3 form or an FAA 8100-9 form, with any inter- nal or external reinforcing structural repair installed. And 6,000 flight cycles.Within 6,000 flight-cycles af- ter rub strip in- stallation, or 1,200 flight-cy- cles after the date on Revi- sion 1 of this service bulletin, whichever oc- curs later. Before 20,000 total flight cy- cles. Remove the rub strips. Do external detailed and sur- face HFEC inspections of the fuselage skin that was under the rub strips, but not under the repair, for cracks in accordance with Paragraph 3.B., Work In- structions, Part 3, Work Package 5 and Work Package 6 (Zone 2 through 6 work only). -1,200 flight-cy- cles after the date on Revi- sion 1 of this service bulletin. At or before 35,000 total flight-cycles. (a) A modification and/or in- spections are required. Airplanes with CRES rub strips installed prior to the original issue of this ser- vice bulletin, approved by Boeing in accordance with an FAA 8110-3 form or an FAA 8100-9 form, with no repairs installed and no skin blends. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 27 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 28 Table 3: Post Modification or Post Repair Inspections of the Fuselage Skin in Areas With Rub Strips In- stalled Prior to the Original Issue of This Service Bulletin Repeat Interval (Not to Exceed) (b) Compliance Time (Whichever Occurs Later ) (b) Action (b)Condition -Within 1,200 flight-cycles af- ter rub strip in- stallation, or within 1,200 flight cycles af- ter the Revision 1 date of this service bulletin, whichever is lat- er. At or before 20,000 total flight-cycles. Remove the rub strips and do external detailed and surface HFEC inspections of the fuselage skin that was under the rub strips for cracks in accordance with Paragraph 3.B., Work In- structions, Part 3, Work Package 5 and 6. Airplanes with CRES rub strips installed prior to the original issue of this ser- vice bulletin, approved by Boeing in accordance with an FAA 8110-3 form or an FAA 8100-9 form, with no repairs installed but with blended skin, and surface HFEC inspection of the skin WAS NOT done prior to rub strip installation. -Within 6,000 flight-cycles af- ter rub strip in- stallation, or within 1,200 flight cycles af- ter the Revision 1 date of this service bulletin, whichever is lat- er. At or before 20,000 total flight-cycles. Remove the rub strips and do external detailed and surface HFEC inspections of the fuselage skin that was under the rub strips for cracks in accordance with Paragraph 3.B., Work In- structions, Part 3, Work Package 5 and 6. Airplanes with CRES rub strips installed prior to the original issue of this ser- vice bulletin, approved by Boeing in accordance with an FAA 8110-3 form or an FAA 8100-9 form, with no repairs installed but with blended skin, and surface HFEC inspection of the skin WAS done prior to rub strip installation. -Before further flight.Install a repair in accor- dance with Paragraph 3.B., Work Instructions, Part 4. If a Local Repair is in- stalled, install new rub strips in accordance with Paragraph 3.B., Work In- structions, Part 1. Any crack found. -Before further flight.Install new rub strips in ac- cordance with Paragraph 3.B., Work Instructions, Part 3. No crack found after rub strip removal. (a) Limit of Validity. Refer to Boeing Service Letter 747-SL-53-088 or Fleet Team Digest 747-FTD-51-07001. (b) If the 8100-9 or 8110-3 that approved installation of the rub strips specifies a more restrictive inspection requirement, then the inspections must be done in accordance with the 8100-9 or 8110-3. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 28 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 29 F. Approval This service bulletin was examined by the Federal Aviation Administration (FAA). The changes specified in this service bulletin comply with the applicable regulations and are FAA approved, as well as European Aviation Safety Agency (EASA)/Joint Aviation Authorities (JAA) approved for all EASA/JAA approved airplanes listed in the service bulletin effectivity. This service bulletin and its approval were based on the airplane in its original Boeing delivery configuration or as modified by other approved Boeing changes. If an airplane has a non-Boeing modification or repair that affects a component or system also affected by this service bulletin, the operator is responsible for obtaining appropriate regulatory agency approval before incorporating this service bulletin. This service bulletin has been approved by the Federal Aviation Administration (FAA). In addition, the Manager of the FAA Seattle Aircraft Certification Office (ACO) approves the accomplishment of the inspection, repair, and modification procedures with the corresponding compliance times specified in Tables 1 through 3 under paragraph 1.E., "Compliance" of Service Bulletin 747-53-2721, Revision 3, as an Alternative Method of Compliance (AMOC) to the inspections, corrective actions, and terminating actions required by paragraphs (f), (i), (j), (k), and (l) of AD 2009-14-02. This AMOC only applies to the areas inspected, repaired, or modified in accordance with this service bulletin. When this service bulletin specifies contacting Boeing for repair instructions, the repair instructions must be approved by the FAA in accordance with paragraph (m) of the AD. All provisions of AD 2009-14-02 that are not specifically referenced in this paragraph remain fully applicable and must be complied with accordingly. G. Manpower The table below shows an estimate of the task hours necessary to do this change for each airplane. This estimate is for direct labor only, done by an experienced crew. Adjust the estimate with operator 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 inspect the work  Time to cure the materials  Time to make the parts  Time to find the tools. Work Package 1 - Forward Rub Strip Installation: Elapsed HoursTask HoursNumber of PersonsTask 4.754.751Open Access 5.0020.004Clean 4.258.502Install Rub Strips 4.754.751Close Access 18.7538.00TOTAL FOR EACH AIRPLANE Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 29 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 30 Work Package 2 - Aft Rub Strip Installation: Elapsed HoursTask HoursNumber of PersonsTask 0.250.251Open Access 4.7519.004Clean 6.2512.502Install Rub Strips 1.501.501Close Access 12.7533.25TOTAL FOR EACH AIRPLANE Work Package 3 - Inspection of the Forward Rub Strip Installation: Elapsed HoursTask HoursNumber of PersonsTask 3.003.001Inspect Rub Strips 3.003.00TOTAL FOR EACH AIRPLANE Work Package 4 - Inspection of the Aft Rub Strip Installation: Elapsed HoursTask HoursNumber of PersonsTask 2.502.501Inspect Rub Strips 2.502.50TOTAL FOR EACH AIRPLANE Work Package 5 - Inspection of the Skin Under the Zone 1 Rub Strip Installation: Elapsed HoursTask HoursNumber of PersonsTask 4.754.751Open Access 2.004.002Remove Existing Rub Strips 5.0020.004Clean 4.258.502Install Rub Strips 4.754.751Close Access 20.7542.00TOTAL FOR EACH AIRPLANE NOTE: More time will be required for additional inspections and repairs if damage is found. Group 1: Zone 1 Full-Length Repair - Post Repair Inspection. Elapsed HoursTask HoursNumber of PersonsTask 4.504.501Open Access 4.5013.503FIGURE 11 4.5013.503FIGURE 12 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 30 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 31 Group 1: Zone 1 Full-Length Repair - Post Repair Inspection. Elapsed HoursTask HoursNumber of PersonsTask 4.504.501Close Access 18.0036.00TOTAL FOR EACH AIRPLANE Group 2: Zone 1 Full-Length Repair - Post Repair Inspection. Elapsed HoursTask HoursNumber of PersonsTask 4.504.501Open Access 5.5022.004FIGURE 13 5.5022.004FIGURE 14 4.504.501Close Access 20.0053.00TOTAL FOR EACH AIRPLANE H. Weight and Balance Changes Change in Moment (Pound-Inches) Change in Weight (Pounds)Airplane + 23801.9+ 9.7Group 1 Rub Strip Installation +20412.6+9.3Group 2 Rub Strip Installation +33531.2+10.7Group 3 Rub Strip Installation I. Electrical Load Data Not changed. J. References 1. Existing Data: a. Engineering Change Memo PRR 85901-83S b. Boeing Service Related Problem (SRP) 747-SRP-53-0296 c. Federal Aviation Administration (FAA) Airworthiness Directive (AD) 2009-14-02, 2010-10-05 d. Standard Overhaul Practices Manual (SOPM) 20-00-00, 20-30-02, 20-42-05, 20-43-03, 20-44-01, 20-44-04, 20-50-12, 20-50-19 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 31 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 32 e. 747-100/200/300 Aircraft Maintenance Manual (AMM) 12-09-05, 12-09-07, 25-22-00, 25-22-07, 55-30-10 f. 747-400 Aircraft Maintenance Manual (AMM) 06-09-05, 06-09-07, 25-22-00, 25-22-04, 55-30-10 g. Boeing Service Bulletin 747-53-2721, 747-53A2367, 747-53A2478 h. Boeing Service Letter 747-SL-53-088 i. 747-100/200/300 Structural Repair Manual (SRM) 51-30-08, 53-30-01 j. 747-400 Structural Repair Manual (SRM) 51-40-08, 53-00-01 k. 747-400F Structural Repair Manual (SRM) 51-40-08, 53-00-01 l. 747-400SF Structural Repair Manual (SRM) 51-40-08, 53-00-01 m. 747 Non-Destructive Testing (NDT) Manual Part 4, 51-00-00, Part 6, 51-00-00, Part 6, 53-30-00 n. 747 Repair Assessment Guidelines (RAG) D6-36181 o. 747-SP Structural Repair Manual (SRM) 51-30-08, 53-31-00 p. 747-400LCF Structural Repair Manual (SRM) 51-40-08, 53-00-01 2. Data Supplied with this Service Bulletin: a. Drawings: ADCNDCN/REVSheetTitleDrawing No --1Kit - Fuselage Skin Repair For Blade Seal Damage, Sect. 46 146U0001 -A3 -A4 -APSDL -B1Kit - Fuselage Skin Repair For Blade Seal Damage, Sect. 48 148U0027 -A16 -B2 -B3 -A4 -A5 -DPSDL Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 32 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 33 3. Installation Drawings Used in the Preparation of this Service Bulletin: TitleDrawing Number PANEL INSTL - STR 3L - STR 3R, STA 2397 - 251765B02703 PANEL INSTL - STR 1 to STR 11, STA 2360 - 259865B02706 This drawing was used to prepare this service bulletin. This drawing is not necessary to make the specified changes, and is not supplied with this service bulletin. This drawing may not be applicable to all airplane configurations or operators. K. Publications Affected 1. Publications: Chapter-SectionPublication 53-30-03747-100/-200/-300 Structural Repair Manual 53-39-01747-SP Structural Repair Manual 53-80-01747-400, -400F, -400SF, and -400 LCF Structural Repair Manual 2. Damage Tolerance Based Structural Inspections: Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the Maintenance Program. This service bulletin affects FCS and new DTI requirements for the structure affected are contained in Paragraph 1.E., Compliance of this service bulletin or in existing documents. L. Interchangeability and Intermixability of Parts Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts. M. Software Accomplishment Summary Not affected. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 33 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 34 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 34 of 140 BOEING SERVICE BULLETIN 747-53-2721 BLANK PAGE ### Page 35 2. MATERIAL INFORMATION A. Material - Price and Availability Boeing can supply the kits shown in Paragraph 2.C., Parts Necessary for Each Airplane. Operators are encouraged to share schedule requirements with Boeing for incorporation of the service bulletin. The kits are subject to the terms and conditions of the Boeing standard purchase order acknowledgment. Prices are in United States Dollars. Terms: Net 30 days. Reference this service bulletin and submit your purchase order by one of these methods: 1. Order on-line via ATA Spec 2000 or The Boeing PART Page 2. Fax to (206) 662-7145 REFER TO THE BOEING PART PAGE ON MYBOEINGFLEET.COM OR CONTACT FIRST RESPONDER AT FR@BOEING.COM FOR THE LATEST REORDER LEAD TIME (ROLT) AND PRICE INFORMATION Unit Price as of the Revision 1 date of this Ser- vice Bulletin (US Dollars) ROLT as of the Revision 1 date of this Service Bul- letin (Calendar Days) NameKit Number $6,035280Top Kit - Forward Rub Strip Instl015U1832-1 $6,075280Top Kit - Aft Rub Strip Instl015U1832-2 $2,881510Repair Kit - Zone 1 Left146U0001-23 $2,881510Repair Kit - Zone 1 Right146U0001-24 $6,253550Repair Kit - Zone 5 Left148U0027-11 $6,253550Repair Kit - Zone 5 Right148U0027-12 Inactive for procurement. Superseded by 148U0027-57. Repair Kit - Zone 4 Left148U0027-21 Inactive for procurement. Superseded by 148U0027-58. Repair Kit - Zone 4 Right148U0027-22 $3,008510Repair Kit - Zone 2 Left148U0027-31 $3,011510Repair Kit - Zone 2 Right148U0027-32 $5,545510Repair Kit - Zone 3 Left148U0027-41 $5,545510Repair Kit - Zone 3 Right148U0027-42 $5,942550Repair Kit - Zone 4 Left148U0027-57 $6,081550Repair Kit - Zone 4 Right148U0027-58 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 35 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 36 Unit Price as of the Revision 2 date of this Ser- vice Bulletin (US Dollars) ROLT as of the Revision 2 date of this Service Bul- letin (Calendar Days) NameKit Number $6,818280Top Kit - Forward Rub Strip Instl - Group 2015U1832-3 $8,772280Top Kit - Forward Rub Strip Instl - Group 3015U1832-4 B. Industry Support Information Boeing warranty remedies are not available for the configuration changes, inspection, and/or repair procedures given in this service bulletin. C. Parts Necessary for Each Airplane 1. Kits/Parts Top Kit 015U1832-1 is used for Work Package 1 - Forward Rub Strip Installation on Group 1 airplanes. Top Kit 015U1832-2 is used for Work Package 2 - Aft Rub Strip Installation on all airplanes. Top Kit 015U1832-3 is used for Work Package 1 - Forward Rub Strip Installation on Group 2 airplanes. Top Kit 015U1832-4 is used for Work Package 1 - Forward Rub Strip Installation on Group 3 airplanes. Kit 015U1832 NotesNameQTYNew Part Number -4-3-2-1 -Top Kit - Forward Rub Strip Instl - Group 1...-015U1832-1 -Top Kit - Aft Rub Strip Instl..-.015U1832-2 -Top Kit - Forward Rub Strip Instl - Group 2.-..015U1832-3 -Top Kit - Forward Rub Strip Instl - Group 3-...015U1832-4 -RUB STRIP.1..146U0043-3 -RUB STRIP.1..146U0043-4 -RUB STRIP.1..146U0043-5 -RUB STRIP.1..146U0043-6 -FILLER.2..146U0043-7 -RUB STRIP...1146U3911-1 -RUB STRIP...1146U3911-2 -RUB STRIP...1146U3911-3 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 36 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 37 Kit 015U1832 NotesNameQTYNew Part Number -4-3-2-1 -RUB STRIP...1146U3911-4 -RUB STRIP11.1148U1202-1 -RUB STRIP..1.148U1202-10 -RUB STRIP11.1148U1202-2 -RUB STRIP..1.148U1202-3 -RUB STRIP..1.148U1202-4 -RUB STRIP..1.148U1202-5 -RUB STRIP..1.148U1202-6 -RUB STRIP..1.148U1202-7 -RUB STRIP..1.148U1202-8 -RUB STRIP..1.148U1202-9 -WASHER624142066-2955-10 -WASHER..8.66-2955-12 -WASHER.22..66-2955-50 -WASHER101041466-2955-75 -WASHER..10.66-2955-9 -RUB STRIP1...814U7317-1 -RUB STRIP1...814U7317-2 -RUB STRIP1...814U7317-3 -RUB STRIP1...814U7317-4 -RUB STRIP1...814U7317-5 -RUB STRIP1...814U7317-6 -RUB STRIP1...814U7317-7 (a)BOLT, HEX HEAD22.2BACB30NM4K10 (a)BOLT, HEX HEAD22.2BACB30NM5K13 (a)BOLT, HEX HEAD22.2BACB30NM5K21 (a)BOLT..2.BACB30NM6K28 (BACB30LM6-28, BACB30LM6K28 optional) (a)BOLT, 100 DEG HEX DR74...BACB30NW6K3X (a)BOLT, 100 DEG HEX DR64...BACB30NW6K4X Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 37 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 38 Kit 015U1832 NotesNameQTYNew Part Number -4-3-2-1 (a)BOLT, 100 DEG HEX DR12...BACB30NW6K5X (a)BOLT, 100 DEG HEX DR2611..BACB30NW6K6X (a)BOLT, 100 DEG HEX DR306..BACB30NW6K7X (a)BOLT, PROTRUDING HD1415..BACB30NX6K2 (a)BOLT, PROTRUDING HD4...BACB30NX6K3 (a)BOLT, PROTRUDING HD.8.8BACB30NX6K3X (a)BOLT, PROTRUDING HD.2..BACB30NX6K4 (a)BOLT, PROTRUDING HD8646BACB30NX6K4X (a)BOLT, PROTRUDING HD4...BACB30NX6K5X (a)BOLT, PROTRUDING HD1610812BACB30NX6K6X (a)BOLT, PROTRUDING HD46648BACB30NX6K7X (a)BOLT, PROTRUDING HD.62.BACB30NX6K8X (a)BOLT, PROTRUDING HD.22.BACB30NX8K4X (a)BOLT, PROTRUDING HD..4.BACB30NX8K6X (a)BOLT, PROTRUDING HD..2.BACB30NX8K7X (a)BOLT, PROTRUDING HD..1414BACB30VT6K2 (a)BOLT, PROTRUDING HEAD..68BACB30VT6K3 (a)BOLT22102BACB30VT6K6 -COLLAR20620..BACC30AG6 -COLLAR1818..BACC30BH6 -COLLAR223025BACC30BL6 -COLLAR74531835BACC30M6 -COLLAR.28.BACC30M8 -NUT22.2BACN11Z4CD -NUT44.4BACN11Z5CD -NUT..2.BACN11Z6CD -RIVET, 100 DEG.55..BACR15GF6D6 -WASHER22.2BACW10BP4CD -WASHER22.2BACW10BP4DP -CSK WASHER44.4BACW10BP5CD -WASHER-PLAIN44.4BACW10BP5DP Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 38 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 39 Kit 015U1832 NotesNameQTYNew Part Number -4-3-2-1 -WASHER, PLAIN..2.BACW10BP6CD -WASHER, SELF-ALIGN..2.BACW10CA6CC -WASHER, SELF-ALIGN..2.BACW10CA6PV (a) If grip length shown is not available at Boeing, fasteners supplied in kits may be one grip length longer than indicated. Also, if any fasteners part numbers listed are not available or have been superseded, substitute fasteners may be supplied in kits. Boeing Document D-590 and Boeing Drawing 65B88700 are used to determine the part numbers used as substitutes. Kit 146U0001 NotesNameQTYNew Part Number -24-23 -REPAIR KIT - ZONE 1 LEFT.-146U0001-23 -REPAIR KIT - ZONE 1 RIGHT-.146U0001-24 -RUB STRIP1.146U3911-10 -RUB STRIP.1146U3911-11 -RUB STRIP1.146U3911-12 -RUB STRIP.1146U3911-9 -WASHER7766-2955-10 -WASHER121266-2955-50 -WASHER2266-2955-52 -RAW MATERIAL - FIELD REPAIR11691U1041-20 (a)BOLT55BACB30MY8K21X (a)BOLT22BACB30MY8K23X (a)BOLT22BACB30NW6K7X (a)BOLT33BACB30NW6K8X (a)BOLT11BACB30NW8K7X (a)BOLT77BACB30NX6K3X (a)BOLT1010BACB30NX6K4X (a)BOLT33BACB30NX6K5X (a)BOLT11BACB30NX6K6X (a)BOLT33BACB30NX6K7X (a)BOLT22BACB30NX6K8X Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 39 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 40 Kit 146U0001 NotesNameQTYNew Part Number -24-23 (a)BOLT11BACB30NX6K9X (a)BOLT33BACB30NX8K6X -COLLAR2727BACC30BH6 -COLLAR33BACC30BH8 -COLLAR55BACC30M6 -COLLAR88BACC30M8 -FILLER11BACF3F009K035NN (a)RIVET132132BACR15BB6D5C (a)RIVET22BACR15BB6D6C (a)RIVET1414BACR15BB6D7C (a)RIVET11BACR15BB6D8C (a)RIVET11BACR15BB7D7C (a)RIVET11BACR15BB7D8C (a)RIVET33BACR15BB9D8C (a)RIVET222222BACR15GF6D5 (a)RIVET88BACR15GF6D6 (a)RIVET1111BACR15GF6D7 (a)RIVET44BACR15GF6D8 (a)RIVET4646BACR15GF7D7 (a)RIVET1111BACR15GF7D8 (a)RIVET22BACR15GF7D9 -SHIM66BACS40R005B005F -SHIM22BACS40R008B073F -SPACER, SLEEVE22NAS42DD10A-26FC -SPACER, SLEEVE33NAS42DD10A-38FC -SPACER, SLEEVE11NAS42DD10A-50FC (a) If grip length shown is not available at Boeing, fasteners supplied in kits may be one grip length longer than indicated. Also, if any fasteners part numbers listed are not available or have been superseded, substitute fasteners may be supplied in kits. Boeing Document D-590 and Boeing Drawing 65B88700 are used to determine the part numbers used as substitutes. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 40 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 41 Kit 148U0027 NotesNameQTYNew Part Number -58-57-22-21 (a)REPAIR KIT - ZONE 4 LEFT...-148U0027-21 (b)REPAIR KIT - ZONE 4 RIGHT..-.148U0027-22 -REPAIR KIT - ZONE 4 LEFT.-..148U0027-57 -REPAIR KIT - ZONE 4 RIGHT-...148U0027-58 -PLATE.1.1148U0027-25 -PLATE1.1.148U0027-26 -RUB STRIP.1.1148U0027-27 -RUB STRIP1.1.148U0027-28 -RUB STRIP.1.1148U0027-29 -RUB STRIP1.1.148U0027-30 -REPAIR DOUBLER.1.1148U0027-53 (148U0027-23 op- tional) -REPAIR DOUBLER1.1.148U0027-54 (148U0027-24 op- tional) -SPLICE.1..65B02810U11 -SPLICE1...65B02810U18 -WASHER19219213613666-2955-10 -WASHER779966-2955-12 -WASHER17317318118166-2955-50 (c)BOLT4444BACB30MY8K10Y (c)BOLT5555BACB30MY8K5Y (c)BOLT6666BACB30MY8K6Y (c)BOLT6666BACB30MY8K7Y (c)BOLT8888BACB30MY8K8Y (c)BOLT7777BACB30NM6K12 (c)BOLT1111BACB30NM6K26 (c)BOLT1111BACB30NM6K28 (c)BOLT..66BACB30NW6K13X (c)BOLT73739090BACB30NW6K14X (c)BOLT3333BACB30NW6K5X Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 41 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 42 Kit 148U0027 NotesNameQTYNew Part Number -58-57-22-21 (c)BOLT5555BACB30NW6K6X (c)BOLT331212BACB30NW6K7X (c)BOLT10101212BACB30NW6K8X (c)BOLT4444BACB30NW6K9X (c)BOLT6666BACB30NX6K11X (c)BOLT5555BACB30NX6K12X (c)BOLT2222BACB30NX6K13X (c)BOLT2222BACB30NX6K14X (c)BOLT66..BACB30NX6K19X (c)BOLT1111BACB30NX6K5X (c)BOLT2244BACB30NX6K7X (c)BOLT1111BACB30NX6K8X (c)BOLT3333BACB30NX8K6 (c)BOLT20202222BACB30NX8K7 (c)BOLT47475050BACB30NX8K8 (c)BOLT1111BACB30VT6K5 (c)BOLT2222BACB30VT6K7 -COLLAR28283030BACC30BH6 -COLLAR72727575BACC30BH8 -COLLAR3333BACC30BL6 -COLLAR101101134134BACC30M6 -COLLAR32323131BACC30R8 -FILLER1111BACF3F010K020NN -NUT9999BACN11Z6CD (c)RIVET146146145145BACR15BB6D6C (c)RIVET6666BACR15BB7D10C (c)RIVET30303030BACR15BB7D7C (c)RIVET8888BACR15BB7D8C (c)RIVET6666BACR15BB7D9C (c)RIVET7777BACR15BB8D10C (c)RIVET16161818BACR15BB8D8C Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 42 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 43 Kit 148U0027 NotesNameQTYNew Part Number -58-57-22-21 (c)RIVET36363636BACR15BB8D9C (c)RIVET7799BACR15BB9D11C (c)RIVET75757575BACR15GF7D10 (c)RIVET14141414BACR15GF7D7 (c)RIVET31312929BACR15GF7D8 (c)RIVET36363333BACR15GF7D9 -SHIM-LAMINATED11..BACS40R010B035F -WASHER, PLAIN9999BACW10BP6CD -WASHER, SELF-ALIGN9999BACW10CA6CC -WASHER, SELF-ALIGN9999BACW10CA6PV -SPACER22..NAS43DD4-38FC -SPACER22..NAS43DD4-46FC -SPACER22..NAS43DD4-51FC (a) Superseded by 148U0027-57. (b) Superseded by 148U0027-58. (c) If grip length shown is not available at Boeing, fasteners supplied in kits may be one grip length longer than indicated. Also, if any fasteners part numbers listed are not available or have been superseded, substitute fasteners may be supplied in kits. Boeing Document D-590 and Boeing Drawing 65B88700 are used to determine the part numbers used as substitutes. Kit 148U0027 NotesNameQTYNew Part Number -42-41-32-31-12-11 -REPAIR KIT - ZONE 5 LEFT.....-148U0027-11 -REPAIR KIT - ZONE 5 RIGHT....-.148U0027-12 -REPAIR KIT - ZONE 2 LEFT...-..148U0027-31 -REPAIR KIT - ZONE 2 RIGHT..-...148U0027-32 -REPAIR KIT - ZONE 3 LEFT.-....148U0027-41 -REPAIR KIT - ZONE 3 RIGHT-.....148U0027-42 -REPAIR DOUBLER.....1148U0027-13 -REPAIR DOUBLER....1.148U0027-14 -REPAIR TRIPLER.....1148U0027-15 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 43 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 44 Kit 148U0027 NotesNameQTYNew Part Number -42-41-32-31-12-11 -REPAIR TRIPLER....1.148U0027-16 -RUB STRIP...1..148U0027-35 -RUB STRIP..1...148U0027-36 -REPAIR DOUBLER.1....148U0027-43 -REPAIR DOUBLER1.....148U0027-44 -RUB STRIP.1....148U0027-45 -RUB STRIP1.....148U0027-46 -REPAIR FILLER.1....148U0027-49 -REPAIR FILLER1.....148U0027-50 -RUB STRIP.....1148U0027-51 -RUB STRIP....1.148U0027-52 -REPAIR DOUBLER...1..148U0027-55 (148U0027-33 op- tional) -REPAIR DOUBLER..1...148U0027-56 (148U0027-34 op- tional) -SKIN PANEL.1....65B02706U323 -SKIN PANEL1.....65B02706U324 -WASHER....303066-2955-10 -WASHER....12012066-2955-12 -WASHER2277..66-2955-50 (a)BOLT..15151515BACB30MY8K19X (a)BOLT....4141BACB30MY8K5X (a)BOLT....4848BACB30MY8K5Y (a)BOLT....1212BACB30MY8K6X (a)BOLT....1313BACB30MY8K6Y (a)BOLT....1818BACB30MY8K7X (a)BOLT..11..BACB30MY8K8X (a)BOLT..99..BACB30NM4K12 (a)BOLT11....BACB30NM5K12 (a)BOLT1133..BACB30NM5K13 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 44 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 45 Kit 148U0027 NotesNameQTYNew Part Number -42-41-32-31-12-11 (a)BOLT44....BACB30NM5K14 (a)BOLT22....BACB30NM5K22 (a)BOLT1818....BACB30NW6K11X (a)BOLT1818....BACB30NW6K12X (a)BOLT9393....BACB30NW6K13X (a)BOLT66....BACB30NW6K4X (a)BOLT..202077BACB30NW6K5X (a)BOLT..2424..BACB30NW6K6X (a)BOLT7775751717BACB30NW6K7X (a)BOLT..4343..BACB30NW6K8X (a)BOLT....2525BACB30NW8K5X (a)BOLT....55BACB30NW8K6X (a)BOLT....22BACB30NW8K7X (a)BOLT....22BACB30NX6K3Y (a)BOLT....55BACB30NX6K4Y (a)BOLT..44..BACB30NX6K5X (a)BOLT..334444BACB30NX6K5Y (a)BOLT..55..BACB30NX6K6X (a)BOLT,..6677BACB30NX6K6Y (a)BOLT111122BACB30NX6K7X (a)BOLT..6622BACB30NX6K7Y (a)BOLT..33..BACB30NX6K8X (a)BOLT..3030..BACB30NX6K8Y (a)BOLT..55..BACB30NX8K5 (a)BOLT..44..BACB30NX8K6 (a)BOLT..66..BACB30NX8K7 (a)BOLT1111..BACB30NX8K7X (a)BOLT14143333..BACB30NX8K8 (a)BOLT..33..BACB30NX8K9 (a)BOLT....3737BACB30VT6K2 (a)BOLT....6565BACB30VT6K3 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 45 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 46 Kit 148U0027 NotesNameQTYNew Part Number -42-41-32-31-12-11 (a)BOLT....8080BACB30VT6K4 (a)BOLT...1..BACB30VT6K5 (a)BOLT..1717..BACB30VT6K7 (a)BOLT....2020BACB30YP6K2 (a)BOLT....245245BACB30YP6K4 (a)BOLT..1717..BACB30YP6K7 -COLLAR..50506262BACC30AC6 -COLLAR..7722BACC30BH6 -COLLAR14145353..BACC30BH8 -COLLAR..3918447447BACC30BL6 -COLLAR1481481731732424BACC30M6 -COLLAR111717126126BACC30M8 -COLLAR....6262BACC30R8 -FILLER, FLAT11....BACF3F030J067AN -NUT..99..BACN11Z4CD -NUT8833..BACN11Z5CD (a)RIVET..11..BACR15BB6D10C (a)RIVET..9696..BACR15BB6D6C (a)RIVET..55..BACR15BB6D7C (a)RIVET..44..BACR15BB6D8C (a)RIVET..33..BACR15BB6D9C (a)RIVET..44..BACR15BB7D7C (a)RIVET..22..BACR15BB7D8C (a)RIVET..22..BACR15BB8D10C (a)RIVET33331919..BACR15BB8D11C (a)RIVET..55..BACR15BB8D9C (a)RIVET..1919..BACR15GF6D10 (a)RIVET..1313..BACR15GF6D7 (a)RIVET..1313..BACR15GF6D8 (a)RIVET..1212..BACR15GF6D9 (a)RIVET58583636..BACR15GF7D10 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 46 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 47 Kit 148U0027 NotesNameQTYNew Part Number -42-41-32-31-12-11 (a)RIVET..1414..BACR15GF7D7 (a)RIVET..1717..BACR15GF7D8 (a)RIVET14142020..BACR15GF7D9 -WASHER..99..BACW10BP4CD -WASHER..99..BACW10BP4DP -CSK WASHER8833..BACW10BP5CD -WASHER-PLAIN8833..BACW10BP5DP -SPACER..11..NAS42DD10A- 14FC -SPACER..22..NAS42DD10A- 16FC -SPACER..22..NAS42DD10A- 25FC -SPACER..22..NAS42DD10A- 28FC -SPACER..11..NAS42DD10A- 29FC -SPACER..11..NAS42DD10A- 33FC -SPACER..22..NAS42DD10A- 34FC -SPACER..11..NAS42DD10A- 35FC -SPACER....33NAS42DD10A- 38FC -SPACER..44..NAS42DD10A- 39FC -SPACER..3333NAS42DD10A- 42FC -SPACER..11..NAS42DD10A- 44FC -SPACER..1166NAS42DD10A- 46FC -SPACER....33NAS42DD10A- 47FC Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 47 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 48 Kit 148U0027 NotesNameQTYNew Part Number -42-41-32-31-12-11 -SPACER..22..NAS42DD10A- 48FC -SPACER..11..NAS42DD10A- 49FC -SPACER..11..NAS42DD10A- 50FC (a) If grip length shown is not available at Boeing, fasteners supplied in kits may be one grip length longer than indicated. Also, if any fasteners part numbers listed are not available or have been superseded, substitute fasteners may be supplied in kits. Boeing Document D-590 and Boeing Drawing 65B88700 are used to determine the part numbers used as substitutes. 2. Parts and Materials Supplied by the Operator NotesNameQTYPart Number / Specifica- tion (a)SEALANT1 PintBMS 5-95 (a)PRIMER1 PintBMS 10-79, Type III (b)CHEMICAL CONVERSION COATING 1 PintALODINE (a)ADHESIVE1 PintBMS 5-92 or BMS 5-123 (c)CHEMICAL STRIPPER1 PintSTRIPPER May be procured from:COLLAR24BACC30BL6 Hi-Shear Corporation 2600 Skypark Drive Torrance, CA 90505 Cage Code 73197 -Bolt2BACB30NX6K14X (a) See the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier data. (b) Refer to SOPM 20-43-03, Type 2, Class A or B for material alternatives and SOPM 20-00-00 for supplier data. (c) Refer to SOPM 20-30-02 for material alternatives and SOPM 20-00-00 for supplier data.. 3. Parts Modified and Reidentified None. 4. Parts Removed and Not Replaced None. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 48 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 49 D. Parts Necessary to Change Spares None. E. Special Tooling - Price and Availability None. F. Special Tooling Necessary to do this Service Bulletin No special tools or equipment are necessary to do the change in this service bulletin. But, maintenance and overhaul tools in the manuals given in Paragraph 1.J., References, can be necessary. Examine operator tool supply to make sure all necessary tools are available. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 49 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 50 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 50 of 140 BOEING SERVICE BULLETIN 747-53-2721 BLANK PAGE ### Page 51 3. ACCOMPLISHMENT INSTRUCTIONS A. GENERAL INFORMATION CAUTION: KEEP THE WORK AREA, WIRES AND ELECTRICAL BUNDLES CLEAN OF METAL PARTICLES OR CONTAMINATION WHEN YOU USE TOOLS. UNWANTED MATERIAL, METAL PARTICLES OR CONTAMINATION CAUGHT IN WIRE BUNDLES CAN CAUSE DAMAGE TO THE BUNDLES. DAMAGED WIRE BUNDLES CAN CAUSE SPARKS OR OTHER ELECTRICAL DAMAGE. NOTE: 1. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for definition of the acronyms. 2. Obey all of the warnings and cautions given in the specified manual sections. 3. Unless shown differently, these dimensions and tolerances are used: – Linear dimensions are in inches – Tolerance on linear dimensions, other than rivet and bolt edge margins, is plus or minus 0.03 inch – Tolerance on rivet and bolt edge margin is plus or minus 0.05 inch – Angular tolerance is plus or minus 2 degrees – Hole dimensions for standard solid rivets are in 747 SRM, Chapter 51 – Torque limits to tighten nuts and bolts are in 747 SRM, Chapter 51 4. Use the approved fastener and process material substitutions in accordance with 747 SRM, Chapter 51. 5. If the length of any fastener specified in this service bulletin does not meet the installation standards in SRM Chapter 51, then a fastener of the same specification, or an approved substitute, with a length which meets the installation standards given in SRM Chapter 51 may be used. In addition, washers may be installed for fastener grip length in accordance with SRM Chapter 51. Refer to SOPM 20-50-01 for alternate full threaded fasteners (screws) needed for installation in this service bulletin. 6. A Detailed Inspection is defined as: An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirrors, magnifying lenses, etc. may be necessary. Surface cleaning and elaborate procedures may be required. 7. These work instructions refer to procedures included in other Boeing documents. When the words "refer to" are used and the operator has an accepted alternative procedure, the accepted alternative procedure can be used. When the words "in accordance with" are included in the instruction, the procedure in the Boeing document must be used. 8. The work instructions are divided into work packages. Task Hours and Elapsed Hours for each package are given in Paragraph 1.G., Manpower. You can do each work package as required. 9. A “Local Repair" is defined as a skin doubler installation that does not extend over the entire length of an affected skin panel. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 51 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 52 10. If necessary to ensure adequate edge margin at all affected fastener locations, it is acceptable for the operator to make new, larger rub strips from 1/2 hard CRES 301 sheet per AMS 5518, 0.016 inch or 0.020 inch thick. Finish any new rub strip with zinc-nickel alloy plate in accordance with BAC 5637, Type II, Class 2 or AMS 2417 Type 2, or cadmium plate in accordance with SOPM 20-42-05 Type 2, Class 2 or QQ-P-416, Type 2, Class 2. After plating, apply one coat of BMS 10-79, Type III primer, then apply BMS 10-86, Type I or Type II abrasion resistant teflon coating in accordance with SOPM 20-44-01 Type 27 (except applied to a thickness of 0.002-0.004 inch) on the exterior surface only. 11. This service bulletin contains instructions to remove and keep parts for installation. However, before installation of any removed and kept part, the part must be in a serviceable condition. Replacement of the removed and kept part with a new or serviceable part of the same part number/specification is an acceptable alternative unless otherwise stated in the service bulletin instructions. 12. Boeing Service Letter 747-SL-51-048, Damage Reporting and Repair Plan/Design Guidelines, is an acceptable procedure to request information from Boeing for additional structural repair instructions. The Service Letter describes what information must be provided to Boeing before a structural repair can be provided. 13. The instructions in Paragraph 3.B., Work Instructions and the figures can include operation of tools or test equipment. Boeing Engineering Tool Drawings, the Illustrated Tool and Equipment Manual, and the Special Tool and Ground Handling Drawing Index contain data on versions of the tools or test equipment that you can use. It is permitted to use replaced tools. It is not permitted to use superseded tools. 14. If it is necessary to remove more parts for access, you can remove those parts. If you can get access without removing identified parts, it is not necessary to remove all of the identified parts. Jacking and shoring limitations must be observed. 15. Where the work instructions include installation of a kept part, a new or serviceable part with the same part number can be installed as an alternative to the kept part. 16. This service bulletin includes functional test procedures for the systems changed by this service bulletin. More functional tests can possibly be necessary in accordance with standard maintenance practices because of interruption to other airplane systems. 17. Some Boeing parts are supplied in a temporary configuration. Those parts are identified with a 'U', 'W', or 'Y' in place of the '-' (dash) in the part number. It is permitted to install parts identified with a 'U', 'W', or 'Y' as an alternative to the '-' (dash) part number. Boeing Drawing 005W0900 contains more data. 18. Additional post modifications inspections of the repaired areas are provided in the applicable Repair Assessment Guidelines (RAG) and/or Structural Repair Manual (SRM). Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 52 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 53 B. WORK INSTRUCTIONS PART 1 - Rub Strip Installation 1. Do inspections of the fuselage skin for wear and cracks at the vertical stabilizer seal interface in accordance with Service Bulletin 747-53A2478. Repair any cracks found in accordance with PART 4. Based on results of the inspections done in accordance with Service Bulletin 747-53A2478, do as follows: a. If the depth of any blend out repair in the skin and fasteners in areas where rub strips will be installed exceeds the limits given in 747-100/200/300 SRM 53-30-01, 747-400 SRM 53-00-01, 747-400F SRM 53-00-01, 747-400SF SRM 53-00-01, 747-SP SRM 53-31-00 or 747-400LCF SRM 53-00-01 a repair must be installed in accordance with PART 4. NOTE: The Full-Length Repairs (repairs that extend over the entire length of an affected skin panel) in PART 4 are for the situation where the skin in the affected zone has been trimmed for the entire length of the affected skin panel. However, it is only necessary to trim out damage in areas where skin wear exceeds the limits given on Drawings 146U0001 and 148U0027. In areas with limited skin trims, it may still be possible to install the Full-Length Repair with fillers where the skin was removed or blended. As an option, Local Repairs can be installed in accordance with the applicable Structural Repair Manual, with tapered fillers adjacent to the Local Repair in accordance with PART 4, and then do the rub strip installation in that area in accordance with Work Package 1 or Work Package 2. b. If no crack or existing Local Repair is in the area and the depth of any blend out repair in the skin in areas where rub strips will be installed does not exceed the limits given in 747-100/200/300 SRM 53-30-01, 747-400 SRM 53-00-01, 747-400F SRM 53-00-01, 747-400SF SRM 53-00-01, 747-SP SRM 53-31-00 or 747-400LCF SRM 53-00-01 do the rub strip installation in accordance with Work Package 1 and Work Package 2. c. If an existing Local Repair is in the area and the depth of any blend out repair in the skin in areas where rub strips will be installed does not exceed the limits given in 747-100/200/300 SRM 53-30-01, 747-400 SRM 53-00-01, 747-400F SRM 53-00-01, 747-400SF SRM 53-00-01, 747-SP SRM 53-31-00 or 747-400LCF SRM 53-00-01 do one of the steps that follow: (1) Remove the Local Repair and install a Full-Length Repair in accordance with PART 4. (2) Install a tapered filler adjacent to the Local Repair in accordance with PART 4 and do the rub strip installation in that area in accordance with Work Package 1 or Work Package 2. Work Package 1 - Forward Rub Strip Installation (Zone 1, Zone 2, and Zone 3): a. Get access to skin on aft side of pressure bulkhead at Station 2360 by removing access door 312A. Refer to 747-400 AMM 06-09-05 or 747-100/200/300 AMM 12-09-05 for access door location. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 53 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 54 b. Group 1-2: Get access to skin on forward side of pressure bulkhead at Station 2360 by removing lowered ceiling panels as necessary between Stations 2280 and 2360. Refer to 747-400 AMM 25-22-04 or 747-100/200/300 AMM 25-22-07 as an accepted procedure. c. Remove ceiling insulation blankets as necessary. Refer to 747-400 AMM 25-22-00 or 747-100/200/300 AMM 25-22-00 as an accepted procedure. d. Group 1: Do the following steps: (1) Remove fasteners and clean the area where rub strips will be installed in accordance with FIGURE 1. NOTE: Rub strips can be used as a template to identify fasteners to be removed and area to be cleaned and inspected. (2) Do High Frequency Eddy Current (HFEC) inspection of the outer skin and around fasteners in area that will be covered by the rub strips in accordance with FIGURE 1. Based on inspection results do as follows: (a) If a crack is in the area, or the depth of any blend out repair in the skin exceeds the limits given in 747-100/200/300 SRM 53-30-01, 747-400 SRM 53-00-01, 747-400F SRM 53-00-01, or 747-400SF SRM 53-00-01, install a repair in accordance with PART 4. The Full-Length Repairs in PART 4 include rub strips. (b) If no crack is in the area, and the depth of any blend out repair in the skin does not exceed the limits given in 747-100/200/300 SRM 53-30-01, 747-400 SRM 53-00-01, 747-400F SRM 53-00-01, or 747-400SF SRM 53-00-01, go to the next step. (3) Do open hole HFEC inspections of the skin at the open fastener holes that will be used to attach the new rub strips in accordance with FIGURE 1. (4) If a fastener hole crack is found, contact The Boeing Company for repair instructions and do the repair or install a repair in accordance with PART 4. The Full-Length Repairs in PART 4 include rub strips. (5) If no fastener hole crack is found, install repair washers and rub strips in accordance with FIGURE 3. e. Group 2: Do the following steps: (1) Remove fasteners and clean area where rub strips will be installed in accordance with FIGURE 7. NOTE: Rub strips can be used as a template to identify fasteners to be removed and area to be cleaned and inspected. (2) Do High Frequency Eddy Current (HFEC) inspection of the outer skin and around fasteners in area that will be covered by the rub strips in accordance with FIGURE 7. Based on inspection results do as follows: Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 54 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 55 (a) If a crack is in the area, or the depth of any blend out repair in the skin exceeds the limits given in 747-SP SRM 53-31-00, install a repair in accordance with Service Bulletin 747-53A2478 or PART 4. The full length repairs include rub strips. (b) If no crack is in the area, and the depth of any blend out repair in the skin does not exceed the limits given in 747-SP SRM 53-31-00, go to next step. (3) Do open hole HFEC inspections of the skin at the open fastener holes that will be used to attach the new rub strips in accordance with FIGURE 7. (4) If a fastener hole crack is found, make the fastener hole up to 1/32 inch oversize in diameter to remove the crack indication. If making the fastener hole oversize does not remove the crack indication, contact The Boeing Company for repair instructions and do the repair or install a repair in accordance with Service Bulletin 747-53A2478 or PART 4. The full length repairs in PART 4 include rub strips. If making the fastener hole oversize does remove the crack indication, install repair washers and rub strips in accordance with FIGURE 8, except install a larger fastener of the same type specified in FIGURE 8 at the repaired fastener hole location. (5) Install repair washers and rub strips in accordance with FIGURE 8. NOTE: 1. On Group 2 airplanes, the rub strip installation in Zone 1 covers the Stringer 4 lap joint. Inspections of the Stringer 4 lap joint are described in Boeing Service Bulletin 747-53A2367, "Fuselage - Skin - Body Skin Lap Joint Inspections Based On Fatigue Test Results" and mandated by AD 2010-10-05. Other inspections of the Stringer 4 lap joint are required by Boeing Document D6-35022, the 747 Supplemental Structural Inspection Document. Accomplishment of these inspections will require periodic removal and replacement of the Zone 1 rub strips. 2. On Group 2 airplanes, if the skin in Zone 1 along the upper row of fasteners in the Stringer 4 lap joint has been previously repaired by blending, Contact The Boeing Company for additional inspection and do the inspection. f. Group 3: Do the following steps: (1) Remove fasteners and clean area where rub strips will be installed in accordance with FIGURE 9. NOTE: Rub strips can be used as a template to identify fasteners to be removed and area to be cleaned and inspected. (2) Do High Frequency Eddy Current (HFEC) inspection of the outer skin and around fasteners in area that will be covered by the rub strips in accordance with FIGURE 9. Based on inspection results do as follows: (a) If a crack is in the area, or the depth of any blend out repair in the skin exceeds the limits given in 747-400LCF SRM 53-00-01, install a repair in accordance with Service Bulletin 747-53A2478 or PART 4. The full length repairs include rub strips. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 55 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 56 (b) If no crack in the area, and the depth of any blend out repair in the skin does not exceed the limits given in 747-400LCF SRM 53-00-01, go to next step. (3) Do open hole HFEC inspections of the skin at the open fastener holes that will be used to attach the new rub strips in accordance with FIGURE 9. (4) If a fastener hole crack is found, make the fastener hole up to 1/32 inch oversize in diameter to remove the crack indication. If making the fastener hole oversize does not remove the crack indication, contact The Boeing Company for repair instructions and do the repair or install a repair in accordance with Service Bulletin 747-53A2478 or PART 4. The full length repairs in PART 4 include rub strips. If making the fastener hole oversize does remove the crack indication, install repair washers and rub strips in accordance with FIGURE 10, except install a larger fastener of the same type specified in FIGURE 10 at the repaired fastener hole location. (5) Install repair washers, fasteners and rub strips in accordance with FIGURE 10. g. Install ceiling insulation blankets previously removed. Refer to 747-400 AMM 25-22-00 or 747-100/200/300 AMM 25-22-00 as an accepted procedure. h. Group 1-2: Install previously removed ceiling panels. Refer to 747-400 AMM 25-22-04 or 747-100/200/300 AMM 25-22-07 as an accepted procedure. i. Install previously removed access door 312A. Refer to 747-400 AMM 06-09-05 or 747-100/200/300 AMM 12-09-05 for access door location. Work Package 2 - Aft Rub Strip Installation (Zone 4, Zone 5, and Zone 6): a. Get internal access to fuselage skin by removing access door 315A. Refer to 747-400 AMM 06-09-05 or 747-100/200/300 AMM 12-09-05 for access door location. b. This step has been deleted. c. This step has been deleted. d. Remove fasteners and clean area where rub strips will be installed in accordance with FIGURE 2. NOTE: Rub strips can be used as a template to identify fasteners to be removed and area to be cleaned and inspected. e. Do a High Frequency Eddy Current (HFEC) inspection of the outer skin and around fasteners in area that will be covered by the rub strips in accordance with FIGURE 2. Based on inspection results do as follows: (1) If a crack is in the area, or the depth of any blend out repair in the skin exceeds the limits given in 747-100/200/300 SRM 53-30-01, 747-400 SRM 53-00-01, 747-400F SRM 53-00-01, 747-400SF SRM 53-00-01, 747-SP SRM 53-31-00 or 747-400LCF SRM 53-00-01, install a repair in accordance with PART 4. The Full-Length Repairs in PART 4 include rub strips. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 56 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 57 (2) If no crack is in the area, and the depth of any blend out repair in the skin does not exceed the limits given in 747-100/200/300 SRM 53-30-01, 747-400 SRM 53-00-01, 747-400F SRM 53-00-01, 747-400SF SRM 53-00-01, 747-SP SRM 53-31-00 or 747-400LCF SRM 53-00-01 go to next step. f. Do open hole HFEC inspections of the skin at the open fastener holes that will be used to attach the new rub strips in accordance with FIGURE 2. g. If a fastener hole crack is found, contact The Boeing Company for repair instructions and do the repair or install a repair in accordance with PART 4. The Full-Length Repairs in PART 4 include rub strips. h. Install repair washers and rub strips in accordance with FIGURE 4. i. This step has been deleted. j. This step has been deleted. k. Install previously removed access door 315A. Refer to 747-400 AMM 06-09-05 or 747-100/200/300 AMM 12-09-05 for access door location. 2. Install previously removed panels 322AL, 322AR, 322BL, 322CL and 324AL. Refer to 747-100/200/300 AMM 55-30-10 or 747-400 AMM 55-30-10 as an accepted procedure. Refer to 747-100/200/300 AMM 12-09-07 or 747-400 AMM 06-09-07 for location of seal panels. 3. Put the airplane back to a serviceable condition. Do inspections in modified areas in accordance with PART 2 and PART 3 at the times given in Paragraph 1.E., Compliance, Tables 1, 2, and 3. PART 2 - Rub Strip and Blade Seal Inspections 1. Do an inspection of installed rub strips as follows: Work Package 3 - Inspection of the Forward Rub Strip Installation (Zone 1, Zone 2, and Zone 3): a. Do a Detailed Inspection of the blade-seal rub-strip contact area. Visually inspect for blade-seal tears, gouges and to ensure uniform contact between blade-seal and rub-strip. b. Get access to blade-seal rub-strip contact surface by gently prying on blade seal with a suitable stiff thin wide blade such-as a 2-3 inch wide putty knife or equivalent and inspect as follows: (1) Do a Detailed Inspection of rub-strips for general wear, loss of adhesion to body skin, buckling, loose/missing fasteners and significant surface wear. NOTE: Significant surface wear here is defined as wear visually discernible as excessive when compared to a surrounding undamaged wear surface. (2) Select all locations of significant surface wear and measure material loss or remaining thickness in accordance with 747 NDT Part 4, 51-00-00, Procedure 2 or Procedure 3. c. If material loss in any rub-strip is greater than 0.008 inch replace with new rub-strip in accordance with Work Package 1. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 57 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 58 d. Replace any torn or gouged blade seals or any loose or missing fasteners. e. Replace any rub strips that are found to have a loss of adhesion to the fuselage skin, or that are found to be buckled in accordance with Work Package 1. Work Package 4 - Inspection of the Aft Rub Strip Installation (Zone 4, Zone 5, and Zone 6): a. Do a Detailed Inspection of the blade-seal rub-strip contact area. Visually inspect for blade-seal tears, gouges and to ensure uniform contact between blade-seal and rub-strip. b. Get access to blade-seal rub-strip contact surface by gently prying on blade seal with a suitable stiff thin wide blade such-as a 2-3 inch wide putty knife or equivalent and inspect as follows: (1) Do a Detailed Inspection of rub-strips for general wear, loss of adhesion to body skin, buckling, loose/missing fasteners and significant surface wear. NOTE: Significant surface wear here is defined as wear visually discernible as excessive when compared to a surrounding undamaged wear surface. (2) Select all locations of significant surface wear and measure material loss or remaining thickness in accordance with 747 NDT Part 4, 51-00-00, Procedure 2 or Procedure 3. c. If material loss in any rub-strip is greater than 0.008 inch replace with new rub-strip in accordance with Work Package 2. d. Replace any torn or gouged blade seals or any loose or missing fasteners. e. Replace any rub strips that are found to have a loss of adhesion to the fuselage skin, or that are found to be buckled in accordance with Work Package 2. PART 3 - Fuselage Skin Inspections - Airplanes that have Rub Strips Installed 1. Remove existing rub strips, inspect the fuselage skin, and install rub strips as follows: NOTE: Work Package 5 below is only necessary for Zone 1 on airplanes with rub strips that were installed in accordance with this service bulletin. Work Package 5 - Inspection of the Skin Under the Forward Rub Strip Installation (Zone 1, Zone 2, and Zone 3): a. Get access to skin on aft side of pressure bulkhead at Station 2360 by removing access door 312A. Refer to 747-400 AMM 06-09-05 or 747-100/200/300 AMM 12-09-05 for access door location. b. Remove panels 322AL, 322AR, 322BL, and 322CL. Refer to 747-100/200/300 AMM 55-30-10 or 747-400 AMM 55-30-10 as an accepted procedure. Refer to 747-100/200/300 AMM 12-09-07 or 747-400 AMM 06-09-07 for location of seal panels. c. Group 1-2: Get access to skin on forward side of pressure bulkhead at Station 2360 by removing lowered ceiling panels as necessary between stations 2280 and 2360. Refer to 747-400 AMM 25-22-04 or 747-100/200/300 AMM 25-22-07 as an accepted procedure. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 58 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 59 d. Remove ceiling insulation blankets as necessary. Refer to 747-400 AMM 25-22-00 or 747-100/200/300 AMM 25-22-00 as an accepted procedure. e. Remove previously installed rub strips and clean fuselage skin in area where rub strips were installed. To clean area refer to FIGURE 1 as an accepted procedure. f. Do High Frequency Eddy Current (HFEC) inspection of the outer skin and around fastener locations in the area that was covered by the rub strips in accordance with FIGURE 1. Based on inspection results do as follows: (1) If a crack is in the area, or the depth of any blend out repair in the skin exceeds the limits given in 747-100/200/300 SRM 53-30-01, 747-400 SRM 53-00-01, 747-400F SRM 53-00-01, 747-400SF SRM 53-00-01, 747-SP SRM 53-31-00 or 747-400LCF SRM 53-00-01 install a repair in accordance with PART 4. The Full-Length Repairs in PART 4 include rub strips. (2) If no crack is in the area, and the depth of any blend out repair in the skin does not exceed the limits given in 747-100/200/300 SRM 53-30-01, 747-400 SRM 53-00-01, 747-400F SRM 53-00-01, 747-400SF SRM 53-00-01, 747-SP SRM 53-31-00 or 747-400LCF SRM 53-00-01 go to the next step. g. Do open hole HFEC inspections of the skin at the open fastener holes that will be used to attach the new rub strips in accordance with FIGURE 1. h. If a fastener hole crack is found, contact The Boeing Company for repair instructions and do the repair or install a repair in accordance with PART 4. The Full-Length Repairs in PART 4 include rub strips. i. Install repair washers and rub strips in accordance with FIGURE 3. j. Install ceiling insulation blankets previously removed. Refer to 747-400 AMM 25-22-00 or 747-100/200/300 AMM 25-22-00 as an accepted procedure. k. Group 1-2: Install previously removed ceiling panels. Refer to 747-400 AMM 25-22-04 or 747-100/200/300 AMM 25-22-07 as an accepted procedure. l. Install previously removed access door 312A. Refer to 747-400 AMM 06-09-05 or 747-100/200/300 AMM 12-09-05 for access door location. m. Install previously removed panels 322AL, 322AR, 322BL, and 322CL. Refer to 747-100/200/300 AMM 55-30-10 or 747-400 AMM 55-30-10 as an accepted procedure. Refer to 747-100/200/300 AMM 12-09-07 or 747-400 AMM 06-09-07 for location of seal panels. n. Put the airplane back to a serviceable condition. Work Package 6 - Inspection of the Skin Under any Aft Rub Strips that were installed prior to the Original Issue of this Service Bulletin (Zone 4, Zone 5, and Zone 6): a. Get access to fuselage skin by removing access door 315A. Refer to 747-400 AMM 06-09-05 or 747-100/200/300 AMM 12-09-05 for access door location. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 59 of 140 BOEING SERVICE BULLETIN 747-53-2721 ### Page 60 b. Remove panel 324AL. Refer to 747-100/200/300 AMM 55-30-10 or 747-400 AMM 55-30-10 as an accepted procedure. Refer to 747-100/200/300 AMM 12-09-07 or 747-400 AMM 06-09-07 for location of seal panels. c. This step has been deleted. d. This step has been deleted. e. Remove previously installed rub strips and clean fuselage skin in area where rub strips were installed. To clean area refer to FIGURE 2 as an accepted procedure. f. Do High Frequency Eddy Current (HFEC) inspection of the outer skin and around fasteners in the area that was covered by the rub strips in accordance with FIGURE 2. Based on inspection results do as follows: (1) If a crack is in the area, or the depth of any blend out repair in the skin exceeds the limits given in 747-100/200/300 SRM 53-30-01, 747-400 SRM 53-00-01, 747-400F SRM 53-00-01, 747-400SF SRM 53-00-01, 747-SP SRM 53-31-00 or 747-400LCF SRM 53-00-01 install a repair in accordance with PART 4. The Full-Length Repairs in PART 4 include rub strips. (2) If no crack is in the area, and the depth of any blend out repair in the skin does not exceed the limits given in 747-100/200/300 SRM 53-30-01, 747-400 SRM 53-00-01, 747-400F SRM 53-00-01, 747-400SF SRM 53-00-01, 747-SP SRM 53-31-00 or 747-400LCF SRM 53-00-01 go to the next step. g. Do open hole HFEC inspections of the skin at the open fastener holes that will be used to attach the new rub strips in accordance with FIGURE 2. h. If a fastener hole crack is found, contact The Boeing Company for repair instructions and do the repair or install a repair in accordance with PART 4. The Full-Length Repairs in PART 4 include rub strips. i. Install repair washers and rub strips in accordance with FIGURE 4. j. This step has been deleted. k. This step has been deleted. l. Install previously removed access door 315A. Refer to 747-400 AMM 06-09-05 or 747-100/200/300 AMM 12-09-05 for access door location. m. Install previously removed panel 324AL. Refer to 747-100/200/300 AMM 55-30-10 or 747-400 AMM 55-30-10 as an accepted procedure. Refer to 747-100/200/300 AMM 12-09-07 or 747-400 AMM 06-09-07 for location of seal panels. n. Put the airplane back to a serviceable condition. PART 4 - Repairs 1. Full-Length Repairs: If necessary, install Full-Length Repairs in affected areas as follows: Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 28, 2009 747-53-2721Revision 3: June 25, 2013 60 of 140 BOEING SERVICE BULLETIN 747-53-2721 The text continues at https://openairdocs.org/service-documents/boeing/sb-747-53-2721/file/fec78260e69d.md?from=61 --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain, except the copies of manufacturers’ service documents, which belong to their rights holders.