# Boeing Service Bulletin 747-78-2178: Revision 1 - Rights: © The Boeing Company. Filed by the FAA in regulations.gov docket FAA-2013-0331; AD 2014-05-19 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. - Document: [Boeing Service Bulletin 747-78-2178](https://openairdocs.org/service-documents/boeing/sb-747-78-2178.md) - Title as filed: U.S. DOT/FAA - SB 747-78-2178 Rev. 1 - Pages: 52 - PDF: https://openairdocs.org/files/sha256/0a/2a/0a2a3154dc064aa8134f495d7bd3526daac85bb2e2d26ea9ca8456408349d17d - Page: https://openairdocs.org/service-documents/boeing/sb-747-78-2178/file/0a2a3154dc06 ## 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: 747-78-2178 Original Issue: January 22, 2009 Revision 1: August 04, 2011 ATA System: 7834 SUBJECT: EXHAUST - Thrust Reverser Control System - Rolls Royce RB211-524 Powered Uncommanded Thrust Reverser Unlock Event, Change Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15 CFR 730-774). 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all export laws. 9E991ECCN: BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET Copyright © 2009 The Boeing Company Unpublished Work - All Rights Reserved Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable subject matter. Boeing also claims copyright in this document as a compilation and/or collective work. This document includes proprietary information owned by The Boeing Company and/or one or more third parties. Treatment of the document and the information it contains is governed by contract with Boeing. For more information, contact The Boeing Company, P.O. Box 3707, Seattle, Washington 98124. Boeing, 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, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8A, Poseidon and the Boeing livery 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. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 1 of 52 3.0 ### Page 2 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 2 of 52 BOEING SERVICE BULLETIN 747-78-2178 BLANK PAGE ### Page 3 Table of Contents Revision Transmittal Sheet ............................................ 5 Summary ...................................................... 7 1. PLANNING INFORMATION ........................................ 9 A. Effectivity ................................................ 9 1. Airplanes ............................................. 9 2. Spares Affected ........................................ 1 0 B. Concurrent Requirements ...................................... 1 0 C. Reason ................................................ 1 0 D. Description .............................................. 1 1 E. Compliance .............................................. 1 1 F. Approval ............................................... 1 1 G. Manpower .............................................. 1 2 H. Weight and Balance Changes .................................... 1 2 I. Electrical Load Data ......................................... 1 3 J. References .............................................. 1 3 1. Existing Data: ......................................... 1 3 2. Data supplied with this Service Bulletin: ........................... 1 3 3. Installation Drawings Used in the Preparation of this Service Bulletin: ........... 1 3 K. Publications Affected ........................................ 1 3 L. Interchangeability and Intermixability of Parts ........................... 1 4 2. MATERIAL INFORMATION ........................................ 1 5 A. Material - Price and Availability ................................... 1 5 B. Industry Support Information .................................... 1 5 C. Parts Necessary For Each Airplane ................................. 1 5 1. Kits/Parts: ........................................... 1 5 2. Parts and Materials Supplied by the Operator: ........................ 1 7 3. Parts Modified and Reidentified: ............................... 1 7 4. Parts Removed and Not Replaced: .............................. 1 7 D. Parts Necessary to Change Spares ................................. 1 7 E. Special Tooling - Price and Availability ............................... 1 7 F. Special Tooling Necessary to do this Service Bulletin ....................... 1 7 3. ACCOMPLISHMENT INSTRUCTIONS .................................. 1 9 A. GENERAL INFORMATION ..................................... 1 9 B. WORK INSTRUCTIONS ....................................... 2 0 FIGURE 1: P252 PANEL - THRUST REVERSER CONTROL - ENGINE 1 AND 2, RELAY CHANGE . 31 FIGURE 2: P252 PANEL - THRUST REVERSER CONTROL - ENGINE 1, W2281 WIRING CHANGE . 36 FIGURE 3: P252 PANEL - THRUST REVERSER CONTROL - ENGINE 2, W2283 WIRING CHANGE . 38 FIGURE 4: P252 PANEL - THRUST REVERSER CONTROL - ENGINE 1 AND ENGINE 2, RETURN ACCESS ............................................ 4 0 FIGURE 5: P253 PANEL - THRUST REVERSER CONTROL - ENGINE 3 AND 4, RELAY CHANGE . 42 FIGURE 6: P253 PANEL - THRUST REVERSER CONTROL - ENGINE 3, W2285 WIRING CHANGE . 47 FIGURE 7: P253 PANEL - THRUST REVERSER CONTROL - ENGINE 4, W2287 WIRING CHANGE . 49 FIGURE 8: P253 PANEL - THRUST REVERSER CONTROL - ENGINE 3 AND ENGINE 4, RETURN ACCESS ............................................ 5 1 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 3 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 4 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 4 of 52 BOEING SERVICE BULLETIN 747-78-2178 BLANK PAGE ### Page 5 Commercial Airplanes 747 Service Bulletin Revision Transmittal SheetNumber: 747-78-2178Original Issue: January 22, 2009 Revision 1: August 04, 2011 ATA System: 7834 SUBJECT: EXHAUST - Thrust Reverser Control System - Rolls Royce RB211-524 Powered Uncommanded Thrust Reverser Unlock Event, Change 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 in accordance with the original issue of this service bulletin. REASON FOR REVISION As a part of a service bulletin validation program, this change was completed on airplane RD142 by Service Bulletin 747-78-2178 Original Issue before the release of Revision 1 of this service bulletin. The change completed on airplane RD142 by Service Bulletin 747-78-2178 Original Issue is equivalent to the release of Revision 1 of this service bulletin. Airplane RD142 has the configuration of a Group 1 airplane. This service bulletin revision is sent to provide operators with the changed service bulletin after the incorporation of the validation findings. During the modification, findings during testing led to a partial rewrite of the functional test to change the voltage check locations. A maintenance zone table has been added to the service bulletin. The Damage Tolerance Based Structural Inspections impact information was added. These sections were changed: 1. Summary Background, Validation Information added. 2. Paragrapgh 1.C, Reason, Validation Information added. 3. Paragrapgh 1.D, Maintenance Zones table added. 4. Paragrapgh 1.K, Publication Affected The Damage Tolerance Based Structural Inspections impact information added. 5. Section 2.C, Parts Necessary for Each Airplane, replaced several kit parts. 6. Paragrapgh 3.A, General Information, added information about lightweight and heavyweight intermix. 7. Paragrapgh 3.B, Work Instructions, added missing steps and changed voltage check location. 8. FIGURE 2, P252 PANEL - THRUST REVERSER CONTROL - ENGINE 1, W2281 WIRING CHANGE, replaced kit parts with new parts. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 5 of 52 ### Page 6 9. FIGURE 3, P252 PANEL - THRUST REVERSER CONTROL - ENGINE 2, W2283 WIRING CHANGE, replaced kit parts with new parts. 10. FIGURE 6, P253 PANEL - THRUST REVERSER CONTROL - ENGINE 3, W2285 WIRING CHANGE, : 11. FIGURE 7, P253 PANEL - THRUST REVERSER CONTROL - ENGINE 4, W2287 WIRING CHANGE, : Vertical lines are put on the left edge of each page, except in Paragraph 1.A., Effectivity, to show the location of important changes. Pages with no vertical lines have no important changes. REVISION HISTORY January 22, 2009Original Issue: August 04, 2011Revision 1: BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 6 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 7 Commercial Airplanes 747 Service Bulletin SummaryNumber: 747-78-2178Original Issue: January 22, 2009 Revision 1: August 04, 2011 ATA System: 7834 SUBJECT: EXHAUST - Thrust Reverser Control System - Rolls Royce RB211-524 Powered Uncommanded Thrust Reverser Unlock Event, Change CONCURRENT REQUIREMENTS Refer to Paragraph 1.B., Concurrent Requirements. BACKGROUND This service bulletin gives instructions to change the thrust reverser control logic in the P252 and the P253 panels. The change to the thrust reverser control logic will electrically isolate the number 2 and number 3 locking gear boxes from the air motor brake unlock proximity sensor. This change will prevent the gear box lock solenoids from receiving electrical power to unlock when the air motor brake proximity sensor senses an uncommanded brake disengagement. This is done by the removal of the air motor brake, release relay, from the thrust reverser control circuit. This change also installs a new unstow, time delay relay, for each engine. The position of the air motor brake, as sensed by the brake proximity sensor, will have no effect on the gear box unlock logic. If the change in this service bulletin is not done, then the number 2 locking gearbox can become unlocked with an associated air motor failure. One operator reported that during takeoff roll on an RB211-524 powered 747-400 airplane, the flight crew received the ENG 4 REV LIMTD EICAS status message and the ENG 4 REVERSER advisory and status messages. During climb, the cabin crew saw sparks from the exhaust of the number 4 engine. As a precaution, the flight crew shutdown the number 4 engine and proceeded with an uneventful air turn-back and landing. The event was found to be caused by a failure of the o-rings in the air motor switcher or shutoff solenoid valves because of overheating. This let the air motor shutoff valve open, which released the air motor brake. This, in the ground mode, energized the number 2 and number 3 thrust reverser gear box unlock solenoids and thereby unlocking the number 2 and number 3, gear boxes. As a part of a service bulletin validation program, this change was completed on airplane RD142 by Service Bulletin 747-78-2178 Original Issue before the release of Revision 1 of this service bulletin. The change completed on airplane RD142 by Service Bulletin 747-78-2178 Original Issue is equivalent to the release of Revision 1 of this service bulletin. Airplane RD142 has the configuration of a Group 1 airplane. Boeing Service Related Problem (SRP) 747-SRP-72-0029 is related to this service bulletin. ACTION (PRR 85901-75S) Remove power to the P252 and P253 panels and the thrust reverser systems. Get access to the P252 and P253 panels. Remove two existing relays and relay sockets from each panel. Add two new relays and relay sockets to each panel. Do the given wiring changes. Do continuity and voltage checks for each engine and the thrust reverser operational test. Return access. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 7 of 52 ### Page 8 EFFECTIVITY 747-200B/-200F/-300/SP airplanes powered by Rolls Royce RB211-524 engines with the lightweight thrust reversers. Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplanes. COMPLIANCE The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin mandatory. Federal Aviation Administration (FAA) Airworthiness Directive 2000-01-05 is related to service bulletin 747-78-2156. Service bulletin 747-78-2156 is related to this service bulletin. Boeing recommends that the change given in this service bulletin be done within 60 months after the date on this service bulletin. INDUSTRY SUPPORT INFORMATION Boeing warranty remedies are not available for the configuration changes given in this service bulletin. MANPOWER Elapsed HoursTotal Task HoursAirplanes 2530Group 1 MATERIAL INFORMATION Boeing Supplied Kits/Parts. Refer to Paragraph 2.A., Material - Price and Availability. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 8 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 9 Commercial Airplanes 747 Service Bulletin Number: 747-78-2178 Original Issue: January 22, 2009 Revision 1: August 04, 2011 ATA System: 7834 SUBJECT: EXHAUST - Thrust Reverser Control System - Rolls Royce RB211-524 Powered Uncommanded Thrust Reverser Unlock Event, Change 1. PLANNING INFORMATION A. Effectivity 1. Airplanes This service bulletin is for the airplanes shown below. An equivalent change is on subsequent production airplanes. Refer to PRR 85901-75S for data about this change. Refer to Service Bulletin Index Document D6-30300 Part 3 for Airplane Variable Number, Line Number, and Serial Number data. DESCRIPTIONCONFIGURATIONGROUP 747-200/-300/SP airplanes powered by Rolls Royce RB211-524 engines with the light weight thrust reversers. -1 Airplane Models: 747-200B, 747-200F, 747-300, 747SP GroupVariable Number 1RB411 - RB413 1RD131 - RD132 1RD135 - RD138 1RD141 - RD144 1RD311 1RD356 - RD358 1RD471 - RD475 1RH101 - RH102 1RR441 - RR442 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 9 of 52 ### Page 10 GroupVariable Number 1RR526 1RR531 1RS271 - RS276 1RS301 - RS306 1RS311 - RS320 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 Gives the instruction to install an additional locking system on the thrust reversers. 747-78-2156, Original Issue or Revision 1Boeing C. Reason This service bulletin gives instructions to change the thrust reverser control logic in the P252 and the P253 panels. The change to the thrust reverser control logic will electrically isolate the number 2 and number 3 locking gear boxes from the air motor brake, unlock proximity sensor. This change will prevent the gear box lock solenoids from receiving electrical power to unlock when the air motor brake proximity sensor senses an uncommanded brake disengagement. This is done by the removal of the air motor brake, release relay, from the thrust reverser control circuit. This change also installs a new unstow, time delay relay, for each engine. The position of the air motor brake, as sensed by the brake proximity sensor, will have no effect on the gear box unlock logic. If the change in this service bulletin is not done, then the number 2 locking gearbox can become unlocked with an associated air motor failure. One operator reported that during takeoff roll on an RB211-524 powered 747-400 airplane, the flight crew received the ENG 4 REV LIMTD EICAS status message and the ENG 4 REVERSER advisory and status messages. During climb, the cabin crew saw sparks from the exhaust of the number 4 engine. As a precaution, the flight crew shutdown the number 4 engine and proceeded with an uneventful air turn-back and landing. The event was found to be caused by a failure of the o-rings in the air motor switcher or shutoff solenoid valves because of overheating. This let the air motor shutoff valve open, which released the air motor brake. This, in the ground mode, energized the number 2 and number 3 thrust reverser gear box unlock solenoids and thereby unlocking the number 2 and number 3, gear boxes. As a part of a service bulletin validation program, this change was completed on airplane RD142 by Service Bulletin 747-78-2178 Original Issue before the release of Revision 1 of this service bulletin. The change completed on airplane RD142 by Service Bulletin 747-78-2178 Original Issue is equivalent to the release of Revision 1 of this service bulletin. Airplane RD142 has the configuration of a Group 1 airplane. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 10 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 11 Revision 1 is sent to provide operators with the changed service bulletin after the incorporation of the validation findings. During the modification, findings during testing led to a partial rewrite of the functional test to change the voltage check locations. A maintenance zone table has been added to the service bulletin. The Damage Tolerance Based Structural Inspections impact information was added. Boeing Service Related Problem (SRP) 747-SRP-72-0029 is related to this service bulletin. D. Description Remove power to the P252 and P253 panels and the thrust reverser systems. Get access to the P252 and P253 panels. Remove two existing relays and relay sockets from each panel. Add two new relays and relay sockets to each panel. Do the given wiring changes. Do continuity and voltage checks for each engine and the thrust reverser operational test. Return access. No more work is necessary on the airplane(s) changed in accordance with the original issue of this service bulletin. The work in this service bulletin is done in the maintenance zone(s) given below. Affected Maintenance Zones ZoneModel 115, 116, 117, 118747-200B, 747-200F, 747-300, 747SP E. Compliance The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin mandatory. Federal Aviation Administration (FAA) Airworthiness Directive 2000-01-05 is related to service bulletin 747-78-2156. Service bulletin 747-78-2156 is related to this service bulletin. Boeing recommends that the change given in this service bulletin be done within 60 months after the date on this service bulletin. 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. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 11 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 12 In addition, the Manager of the FAA Seattle Aircraft Certification Office approves the action (i.e. inspection or modification) defined in this service bulletin as an alternative method of compliance to the requirements of paragraph (c) of FAA AD 2000-01-05. All provisions of FAA AD 2000-01-05 that are not specifically referenced in the above statement remain fully applicable and must be complied with. 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 examine the work — Time to cure the materials — Time to make the parts — Time to find the tools. This estimate does not include the task-hour data given in the service bulletins in Paragraph 1.B., Concurrent Requirements. Elapsed HoursTask-HoursNumber of Per- sons Task 0.250.251Open Access 1.01.01Figure 1 4.254.251Figure 2 4.254.251Figure 3 0.250.251Figure 4 1.01.01Figure 5 4.254.251Figure 6 4.254.251Figure 7 0.250.251Figure 8 0.250.251Close Access 5102Continuity Checks and Functional Tests 2530TOTAL FOR EACH AIRPLANE H. Weight and Balance Changes Change in Moment (Pound-Inches) Change in Weight (Pounds) Airplane +315.0+0.9747-200, 747-300 +495.0+0.9747 SP BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 12 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 13 I. Electrical Load Data Not applicable. J. References 1. Existing Data: a. Engineering Change Memo PRR 85901-75S b. 747-100/200/300 Aircraft Maintenance Manual (AMM) 24-22-00, 36-00-00, 78-30-00, 78-30-01 c. 747 Wiring Diagram 78-34-12, 78-34-22, 78-34-32, 78-34-42 d. Standard Wiring Practices Manual SWPM 20-00-13, 20-10-11, 20-10-12, 20-10-19, 20-61-11, 20-81-12, 20-81-22, 20-90-11, 20-90-15 e. Standard Overhaul Practices Manual (SOPM) 20-50-05, 20-50-10 f. Service Related Problem (SRP) 747-SRP-72-0029 g. Boeing Service Bulletin 747-78-2156 h. Federal Aviation Administration (FAA) Airworthiness Directive 2000-01-05 i. Boeing Drawing 012W6100 2. Data supplied with this Service Bulletin: None. 3. Installation Drawings Used in the Preparation of this Service Bulletin: None. K. Publications Affected 1. Publications: Chapter-SectionPublication 78-34-12, 78-34-22, 78-34-32, 78-34-42747 Wiring Diagram 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 does not affect FCS, therefore DTIs are not necessary. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 13 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 14 Chapter-SectionPublication 78-34-12, 78-34-22, 78-34-32, 78-34-42747 Wiring Diagram Manual L. Interchangeability and Intermixability of Parts Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 14 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 15 2. MATERIAL INFORMATION A. Material - Price and Availability Boeing can supply the kits shown in Paragraph 2.C., Parts Necessary For Each Airplane. If there is a limit to the quantity (QTY) of available kits, a supply sequence is given by Spares. More kits become available as shown in the Reorder Lead Time (ROLT). ROLT is calculated from the date Boeing gets the purchase order. The kits are subject to the terms and conditions of the Boeing standard purchase order acknowledgment. After the Unit Price date, new price and ROLT data is applicable. Prices are in United States dollars. Terms: Net 30 days. Reference this service bulletin and submit your purchase order by one of the methods that follow: 1. Order on-line via ATA Spec 2000 or Boeing Part Page 2. Fax to (206) 662-7145 3. Spares Customer Support - MC 36-65 Boeing Spares Department P.O. Box 3707 Seattle, Washington 98124-2207 USA Unit Price thru Apr 30, 2008 ROLT (Weeks) QTYDateNameKit Number $4,289221November 8, 2007Top Kit015U1820-3 B. Industry Support Information Boeing warranty remedies are not available for the configuration changes given in this service bulletin. C. Parts Necessary For Each Airplane 1. Kits/Parts: NOTE: One top kit and the items shown in Paragraph 2.C.2., Parts and Materials Supplied by the Operator, are necessary for each airplane. To get the kits/parts shown below, refer to Paragraph 2.A., Material - Price and Availability. Kit 015U1820-3 NotesNameQTYNew Part Number -3 TOP KIT - RR Powered 747 Uncommanded Thrust Reverser Unlock Events -015U1820-3 LACING TAPE - WHITE (135C) 100 FT1289T9001-91 ROLLS ROYCE POWERED 747 UNCOMMANDED THRUST REVERSER UNLOCK ENG 1 (W2281) 161B20562-101 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 15 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 16 Kit 015U1820-3 NotesNameQTYNew Part Number -3 ROLLS ROYCE POWERED 747 UNCOMMANDED THRUST REVERSER UNLOCK ENG 2 (W2283) 161B20562-102 ROLLS ROYCE POWERED 747 UNCOMMANDED THRUST REVERSER UNLOCK ENG 3 (W2285) 161B20562-103 ROLLS ROYCE POWERED 747 UNCOMMANDED THRUST REVERSER UNLOCK ENG 4 (W2287) 161B20562-104 TAPE, ID4BACT19J2 TIME DELAY RELAY4TDH-8120-1001 Wire Kit 61B20562 NotesNameQTYNew Part Number -101-102-103-104 WIRE KIT - ROLLS ROYCE POWERED 747 UN- COMMANDED THRUST REVERSER UNLOCK ENG 1 (W2281) -...61B20562-101 WIRE KIT - ROLLS ROYCE POWERED 747 UN- COMMANDED THRUST REVERSER UNLOCK ENG 2 (W2283) .-..61B20562-102 WIRE KIT - ROLLS ROYCE POWERED 747 UN- COMMANDED THRUST REVERSER UNLOCK ENG 3 (W2285) ..-.61B20562-103 WIRE KIT - ROLLS ROYCE POWERED 747 UN- COMMANDED THRUST REVERSER UNLOCK ENG 4 (W2287) ...-61B20562-104 WIRE CUT & CODE1...61B20562-101W WIRE CUT & CODE.1..61B20562-102W WIRE CUT & CODE..1.61B20562-103W WIRE CUT & CODE...161B20562-104W I.D. TAPE1...61B20562-10101 I.D. TAPE.1..61B20562-10201 I.D. TAPE..1.61B20562-10301 I.D. TAPE...161B20562-10401 (a)CONTACT, SOCKET3333BACC47CP1 (a)CONTACT, PIN7777M39029/11-145 (a)CONTACT, SOCKET7777BACC47DJ1 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 16 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 17 Wire Kit 61B20562 NotesNameQTYNew Part Number -101-102-103-104 (a)SLEEVE, SOLDER (HEAT SHRINK)3333BACS13CT2C (a)SLEEVE, SOLDER (HEAT SHRINK)2222BACS13CT3N RELAY SOCKET1111BACS16W5A (a)CONTACT, PIN, SIZE 204444S280W555-920 (a) There are more parts than are necessary. 2. Parts and Materials Supplied by the Operator: None. 3. Parts Modified and Reidentified: None. 4. Parts Removed and Not Replaced: None. D. Parts Necessary to Change Spares None. E. Special Tooling - Price and Availability None. F. Special Tooling Necessary to do this Service Bulletin No special tools or equipment are necessary to do the change in this service bulletin. But, maintenance and overhaul tools in the manuals given in Paragraph 1.J., References, can be necessary. Examine operator tool supply to make sure all necessary tools are available. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 17 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 18 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 18 of 52 BOEING SERVICE BULLETIN 747-78-2178 BLANK PAGE ### Page 19 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 given in 747 Structural Repair Manual, Chapter 51 — Torque limits to tighten nuts and bolts are given in 747 Structural Repair Manual, Chapter 51. 4. For approved fastener and process material substitutions, refer to 747 Structural Repair Manual, Chapter 51, Alternate fasteners are given in 747 Structural Repair Manual Chapter 51 and Boeing Drawing 012W6100. 5. Refer to the Boeing Standard Wiring Practices Manuals SWPM 20-10-11, SWPM 20-10-12 and SWPM 20-10-19 for the wire installation procedures. 6. If the length of fasteners specified in this service bulletin do not meet the installation standards, fasteners of the same specification, or an approved substitute, one grip length longer or shorter may be used. 7. These work instructions refer to procedures included on other Boeing documents. When the words "refer to" are used and the operator has an accepted alternative procedure, the accepted alternative procedure can be used. When the words "as given in" are included in the instruction, the procedure in the Boeing document must be used. 8. Because intermix of lightweight and heavyweight thrust reversers is allowed on the same aircraft, the aircraft wiring for the lightweight configuration should be changed even though a heavyweight thrust reverser is installed, since there is the capability for a lightweight reverser to be installed on the plane. The functional test should pass even if a heavyweight thrust reverser is installed. When the heavyweight thrust reverser is replaced with a lightweight thrust reverser, the operator must successfully complete the functional test in this service bulletin for that engine prior to dispatch or lock out the reverser per the Master Minimum Equipment List (MMEL) until the functional test in this service bulletin is successfully completed. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 19 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 20 B. WORK INSTRUCTIONS 1. Open these circuit breakers on the P6 and P12 panels. Install safety tags. P6 Main Power Distribution Panel NameCircuit Breaker Number T/R LOCK CONT ENG 1C10934 T/R LOCK CONT ENG 2C10935 P12 Overhead Circuit Breaker Panel NameCircuit Breaker Number T/R IND ENG 1C00405 T/R CONT ENG 1C01703 T/R IND ENG 2C00402 T/R CONT ENG 2C01704 2. Get access to the P252 Panel. Remove two relays and relay sockets, and install two relays and relay sockets, as given in Figure 1.  R8965 - Relay, Thrust Reverser Unstowed Engine 1  R8966 - Relay, Thrust Reverser Unstowed Engine 2 3. Do the W2281 wiring changes in the P252 Panel, as given in Figure 2. 4. Do the W2283 wiring changes in the P252 Panel, as given in Figure 3. 5. Open these circuit breakers on the P6 and P12 panels. Install safety tags. P6 Main Power Distribution Panel NameCircuit Breaker Number T/R LOCK CONT ENG 3C10936 T/R LOCK CONT ENG 4C10937 P12 Overhead Circuit Breaker Panel NameCircuit Breaker Number T/R IND ENG 3C00403 T/R CONT ENG 3C01442 T/R IND ENG 4C00404 T/R CONT ENG 4C01441 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 20 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 21 6. Get access to the P253 Panel. Remove two relays and relay sockets, and install two relays and relay sockets, as given in Figure 5.  R8967 - Relay, Thrust Reverser Unstowed Engine 3  R8968 - Relay, Thrust Reverser Unstowed Engine 4 7. Do the W2285 wiring changes in the P253 Panel, as given in Figure 6. 8. Do the W2287 wiring changes in the P253 Panel, as given in Figure 7. 9. Close these circuit breakers on the P6 and P12 panels. Remove the safety tags. P6 Main Power Distribution Panel NameCircuit Breaker Number T/R LOCK CONT ENG 1C10934 T/R LOCK CONT ENG 2C10935 T/R LOCK CONT ENG 3C10936 T/R LOCK CONT ENG 4C10937 P12 Overhead Circuit Breaker Panel NameCircuit Breaker Number T/R IND ENG 1C00405 T/R CONT ENG 1C01703 T/R IND ENG 2C00402 T/R CONT ENG 2C01704 T/R IND ENG 3C00403 T/R CONT ENG 3C01442 T/R IND ENG 4C00404 T/R CONT ENG 4C01441 10. Do the following continuity and voltage check for Engine #1. a. Make sure that there is electrical power applied to the airplane. Refer to 747-100/200/300 AMM 24-22-00, as an accepted procedure. b. Open this circuit breaker on the P6 Panel and install a safety tag. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 21 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 22 P6 Main Power Distribution Panel NameCircuit Breaker Number T/R LOCK CONT ENG 1C10934 c. Disconnect the connector D17821P from the P252 Panel. d. Remove the relays R8021, R8685 and R8965 from the P252 Panel. e. Do a wiring continuity check to make sure there is continuity (less than 7.5 ohms) between the connector pins given in the table below. All continuity check locations are in the P252 Panel except as noted. Pin #TOPin #FROM 17D1782033D17821J B1DR896533D17821J B2DR89656D17821J C1DR8965B2DR8021 X1DR896530D17821J A2DR868530D17821J B1DR802130D17821J X1DR802130D17821J X1DR868522D17821J A1DR868522D17821J f. Do a wiring continuity check to make sure there is NOT continuity between the connector pins given in the table below. All continuity checks are in the P252 Panel. Pin #TOPin #FROM B2DR802133D17821J B1DR80216D17821J X1DR802122D17821J X1DR8021X1DR8685 X1DR8021A1DR8965 g. Connect the connector D17821P to the P252 panel. h. Install the relays R8021, R8685 and R8965 from the P252 Panel. i. Make sure the applicable thrust reverser is fully stowed. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 22 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 23 j. Make sure pneumatic pressure is not applied to the airplane. To remove pneumatic pressure refer to 747-100/200/300 AMM 36-00-00, as an accepted procedure. k. Release the air motor brake. Pull the air motor brake manual release handle forward and rotate counterclockwise to lock in the released position. l. Set the air motor manual override switch to CLOSED. Refer to 747-100/200/300 AMM 78-30-01, as an accepted procedure. m. Close this circuit breaker on the P6 Panel and remove the safety tag. P6 Main Power Distribution Panel NameCircuit Breaker Number T/R LOCK CONT ENG 1C10934 n. Measure these voltages: (1) Make sure that there are 0 - 1.5 volts between terminal block TBD17, position Z7, and a ground in the P252 panel. (2) Make sure that there are more than 24 volts between pin number 1 and pin number 2 at connector DV225 (Gear Box Lock Solenoid Number 3). o. Manually drive the thrust reverser cowl approximately 2 inches in the deploy direction. p. Measure this voltage: (1) Make sure that there are more than 24 volts between terminal block TBD17, position Z7, and a ground in the P252 panel. q. Manually drive the thrust reverser cowl to the fully stowed and locked position. Then after 1 second, measure this voltage: (1) Make sure that there are 0 - 1.5 volts between terminal block TBD17, position Z7, and a ground in the P252 panel. r. Open this circuit breaker on the P6 Panel and install a safety tag. P6 Main Power Distribution Panel NameCircuit Breaker Number T/R LOCK CONT ENG 1C10934 s. Unlock the gear boxes and manually stow the thrust reverser. t. Manually engage the air motor brake. Pull the air motor brake manual release handle forward and rotate clockwise to lock in the engaged position. u. Set the air motor manual override switch to OPEN. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 23 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 24 11. Do the following continuity and voltage check for Engine #2. a. Make sure that there is electrical power applied to the airplane. Refer to 747-100/200/300 AMM 24-22-00, as an accepted procedure. b. Open this circuit breaker on the P6 Panel and install a safety tag. P6 Main Power Distribution Panel NameCircuit Breaker Number T/R LOCK CONT ENG 2C10935 c. Disconnect the connector D17824P from the P252 Panel. d. Remove the relays R8022, R8686 and R8966 from the P252 Panel. e. Do a wiring continuity check to make sure there is continuity (less than 7.5 ohms) between the connector pins given in the table below. All continuity check locations are in the P252 Panel except as noted. Pin #TOPin #FROM 17D1782333D17824J B1DR896633D17824J B2DR89666D17824J C1DR8966B2DR8022 X1DR896630D17824J A2DR868630D17824J B1DR802230D17824J X1DR802230D17824J X1DR868622D17824J A1DR868622D17824J f. Do a wiring continuity check to make sure there is NOT continuity between the connector pins given in the table below. All continuity checks are in the P252 Panel. Pin #TOPin #FROM B2DR802233D17824J B1DR80226D17824J X1DR802222D17824J X1DR8022X1DR8686 X1DR8022A1DR8966 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 24 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 25 g. Connect the connector D17824P to the P252 panel. h. Install relays R8022, R8686 and R8966. i. Make sure the applicable thrust reverser is fully stowed. j. Make sure pneumatic pressure is not applied to the airplane. To remove pneumatic pressure refer to 747-100/200/300 AMM 36-00-00, as an accepted procedure. k. Release the air motor brake. Pull the air motor brake manual release handle forward and rotate counterclockwise to lock in the released position. l. Set the air motor manual override switch to CLOSED. Refer to 747-100/200/300 AMM 78-30-01, as an accepted procedure. m. Close this circuit breaker on the P6 Panel and remove the safety tag. P6 Main Power Distribution Panel NameCircuit Breaker Number T/R LOCK CONT ENG 2C10935 n. Measure these voltages: (1) Make sure that there are 0 - 1.5 volts between terminal block TBD18, position Z7, and a ground in the P252 panel. (2) Make sure that there are more than 24 volts between pin number 1 and pin number 2 at connector DV225 (Gear Box Lock Solenoid Number 3). o. Manually drive the thrust reverser cowl approximately 2 inches in the deploy direction. p. Measure this voltage: (1) Make sure that there are more than 24 volts between terminal block TBD18, position Z7, and a ground in the P252 panel. q. Manually drive the thrust reverser cowl to the fully stowed and locked position. Then after 1 second, measure this voltage: (1) Make sure that there are 0 - 1.5 volts between terminal block TBD18, position Z7, and a ground in the P252 panel. r. Open this circuit breaker on the P6 Panel and install a safety tag. P6 Main Power Distribution Panel NameCircuit Breaker Number T/R LOCK CONT ENG 2C10935 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 25 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 26 s. Unlock the gear boxes and manually stow the thrust reverser. t. Manually engage the air motor brake. Pull the air motor brake manual release handle forward and rotate clockwise to lock in the engaged position. u. Set the air motor manual override switch to OPEN. Refer to 747-100/200/300 AMM 78-30-01, as an accepted procedure. 12. Close access to the P252 Panel, as given in Figure 4. 13. Do the following continuity and voltage check for Engine #3. a. Make sure that there is electrical power applied to the airplane. Refer to 747-100/200/300 AMM 24-22-00, as an accepted procedure. b. Open this circuit breaker on the P6 Panel and install a safety tag. P6 Main Power Distribution Panel NameCircuit Breaker Number T/R LOCK CONT ENG 3C10936 c. Disconnect the connector D17827P from the P253 Panel. d. Remove the relays R8023, R8687 and R8967 from the P253 Panel. e. Do a wiring continuity check to make sure there is continuity (less than 7.5 ohms) between the connector pins given in the table below. All continuity check locations are in the P253 Panel except as noted. Pin #TOPin #FROM 17D1782633D17827J B1DR896733D17827J B2DR89676D17827J C1DR8967B2DR8023 X1DR896730D17827J A2DR868730D17827J B1DR802330D17827J X1DR802330D17827J X1DR868722D17827J A1DR868722D17827J f. Do a wiring continuity check to make sure there is NOT continuity between the connector pins given in the table below. All continuity checks are in the P253 Panel. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 26 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 27 Pin #TOPin #FROM B2DR802333D17827J B1DR80236D17827J X1DR802322D17827J X1DR8023X1DR8687 X1DR8023A1DR8967 g. Connect the connector D17827P to the P253 panel. h. Install relays R8023, R8687 and R8967. i. Make sure the applicable thrust reverser is fully stowed. j. Make sure pneumatic pressure is not applied to the airplane. To remove pneumatic pressure refer to 747-100/200/300 AMM 36-00-00, as an accepted procedure. k. Release the air motor brake. Pull the air motor brake manual release handle forward and rotate counterclockwise to lock in the released position. l. Set the air motor manual override switch to CLOSED. Refer to 747-100/200/300 AMM 78-30-01, as an accepted procedure. m. Close this circuit breaker on the P6 Panel and remove the safety tag. P6 Main Power Distribution Panel NameCircuit Breaker Number T/R LOCK CONT ENG 3C10936 n. Measure these voltages: (1) Make sure that there is 0 - 1.5 volts between terminal block TBD19, position Z7, and a ground in the P253 panel. (2) Make sure that there are more than 24 volts between pin number 1 and pin number 2 at connector DV225 (Gear Box Lock Solenoid Number 3). o. Manually drive the thrust reverser cowl approximately 2 inches in the deploy direction. p. Measure this voltage: (1) Make sure that there is more than 24 volts between terminal block TBD19, position Z7, and a ground in the P253 panel. q. Manually drive the thrust reverser cowl to the fully stowed and locked position. Then after 1 second, measure this voltage: BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 27 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 28 (1) Make sure that there is 0 - 1.5 volts between terminal block TBD19, position Z7, and a ground in the P253 panel. r. Open this circuit breaker on the P6 Panel and install a safety tag. P6 Main Power Distribution Panel NameCircuit Breaker Number T/R LOCK CONT ENG 3C10936 s. Unlock the gear boxes and manually stow the thrust reverser. t. Manually engage the air motor brake. Pull the air motor brake manual release handle forward and rotate clockwise to lock in the engaged position. u. Set the air motor manual override switch to OPEN. Refer to 747-100/200/300 AMM 78-30-01, as an accepted procedure. 14. Do the following continuity and voltage check for Engine #4. a. Make sure that there is electrical power applied to the airplane. Refer to 747-100/200/300 AMM 24-22-00, as an accepted procedure. b. Open this circuit breaker on the P6 Panel and install a safety tag. P6 Main Power Distribution Panel NameCircuit Breaker Number T/R LOCK CONT ENG 4C10937 c. Disconnect the connector D17830P from the P253 Panel. d. Remove the relays R8024, R8688 and R8968 from the P253 Panel. e. Do a wiring continuity check to make sure there is continuity (less than 7.5 ohms) between the connector pins given in the table below. All continuity check locations are in the P253 Panel except as noted. Pin #TOPin #FROM 17D1782933D17830J B1DR896833D17830J B2DR89686D17830J C1DR8968B2DR8024 X1DR896830D17830J A2DR868830D17830J B1DR802430D17830J BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 28 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 29 Pin #TOPin #FROM X1DR802430D17830J X1DR868822D17830J A1DR868822D17830J f. Do a wiring continuity check to make sure there is NOT continuity between the connector pins given in the table below. All continuity checks are in the P253 Panel. Pin #TOPin #FROM B2DR802433D17830J B1DR80246D17830J X1DR802422D17830J X1DR8024X1DR8688 X1DR8024A1DR8968 g. Connect the connector D17830P to the P253 panel. h. Install relays R8024, R8688 and R8968. i. Make sure the applicable thrust reverser is fully stowed. j. Make sure pneumatic pressure is not applied to the airplane. To remove pneumatic pressure refer to 747-100/200/300 AMM 36-00-00, as an accepted procedure. k. Release the air motor brake. Pull the air motor brake manual release handle forward and rotate counterclockwise to lock in the released position. l. Set the air motor manual override switch to CLOSED. Refer to 747-100/200/300 AMM 78-30-01, as an accepted procedure. m. Close this circuit breaker on the P6 Panel and remove the safety tag. P6 Main Power Distribution Panel NameCircuit Breaker Number T/R LOCK CONT ENG 4C10937 n. Measure these voltages: (1) Make sure that there is 0 - 1.5 volts between terminal block TBD20, position Z7, and a ground in the P253 panel. (2) Make sure that there are more than 24 volts between pin number 1 and pin number 2 at connector DV225 (Gear Box Lock Solenoid Number 3). o. Manually drive the thrust reverser cowl approximately 2 inches in the deploy direction. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 29 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 30 p. Measure this voltage: (1) Make sure that there is more than 24 volts between terminal block TBD20, position Z7, and a ground in the P253 panel. q. Manually drive the thrust reverser cowl to the fully stowed and locked position. Then after 1 second, measure this voltage: (1) Make sure that there is 0 - 1.5 volts between terminal block TBD20, position Z7, and a ground in the P253 panel. r. Open this circuit breaker on the P6 Panel and install a safety tag. P6 Main Power Distribution Panel NameCircuit Breaker Number T/R LOCK CONT ENG 4C10937 s. Unlock the gear boxes and manually stow the thrust reverser. t. Manually engage the air motor brake. Pull the air motor brake manual release handle forward and rotate clockwise to lock in the engaged position. u. Set the air motor manual override switch to OPEN. Refer to 747-100/200/300 AMM 78-30-01, as an accepted procedure. 15. Return access to the P253 Panel, as given in Figure 8. 16. Do the Thrust Reverser Operational Test as given in 747-100/200/300 AMM 78-30-00. 17. Put the airplane back to a serviceable condition. BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1: August 04, 2011 30 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 31 (OCR) BOEING SERVICE BULLETIN 747-78-2178 1 P252 PANEL / n > FWD P252 PANEL LEFT THRUST REVERSER RELAY 1345472 FIGURE 1: P252 PANEL - THRUST REVERSER CONTROL - ENGINE 1 AND 2, RELAY CHANGE (SHEET 1 OF 5) Original Issue: January 22, 2009 Revision 1 August 04, 2011 BOEING PROPRIETARY - 747-78-2178 Copyright © Unpublished Work - See page 1 for details. 31 of 52 ### Page 32 (OCR) BOEING SERVICE BULLETIN 747-78-2178 Morro → SEE B 12/17 →FWD P252 PANEL LEFT THRUST REVERSER RELAY A-A 1345500 FIGURE 1: P252 PANEL - THRUST REVERSER CONTROL - ENGINE 1 AND 2, RELAY CHANGE (SHEET 2 OF 5) Original Issue: January 22, 2009 Revision 1 August 04, 2011 BOEING PROPRIETARY - 747-78-2178 Copyright © Unpublished Work - See page 1 for details. 32 of 52 ### Page 33 (OCR) BOEING SERVICE BULLETIN 747-78-2178 15 16) → FWD P252 PANEL LEFT THRUST REVERSER RELAY 1345550 FIGURE 1: P252 PANEL - THRUST REVERSER CONTROL - ENGINE 1 AND 2, RELAY CHANGE (SHEET 3 OF 5) Original Issue: January 22, 2009 Revision 1 August 04, 2011 BOEING PROPRIETARY - 747-78-2178 Copyright © Unpublished Work - See page 1 for details. 33 of 52 ### Page 34 The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for each airplane. The parts necessary to do this figure are found in Top Kit 015U1820-3, wire kit 61B20562-101 and wire kit 61B20562-102. NOTE: The relay panel assemblies that hold the relays must not be installed when this figure is completed, because there are wiring changes done behind these panels. The return access to the P252 Panel will do this work in a separate figure. MORE DATAQTYIDENTIFICATIONNAMETASKSTEP -1-P252 PanelAccess1 -1-P252 Panel DoorOpen2 -1-Relay (R1269)Remove3 -4-ScrewsRemove/Keep4 to get access to remove the relay socket. Support the relay panel as necessary to not put strain on the wire bundle. 1-Panel AssemblyMove5 (a)1-Relay SocketRemove6 (a) (b)1BACS16W5ARelay SocketInstall (New)7 (b)1TDH-8120-1001Relay (R8965)Install (New)8 with relay number R1269.1-I.D. TapeRemove9 below the new relay. Refer to SOPM 20-50-05, as an accept- ed procedure. 1BACT19J2I.D. TapeInstall (New)10 to the I.D. Tape. Refer to SOPM 20-50-10, as an accept- ed procedure. 1R8965Relay NumberApply11 -1-Relay (R1270)Remove12 -4-ScrewsRemove/Keep13 to get access to remove a relay socket. Support the relay panel as necessary to not put strain on the wire bundle. 1-Panel AssemblyMove14 (a)1-Relay SocketRemove15 (a) (b)1BACS16W5ARelay SocketInstall (New)16 (b)1TDH-8120-1001Relay (R8966)Install (New)17 with relay number R1270.1-I.D. TapeRemove18 FIGURE 1: P252 PANEL - THRUST REVERSER CONTROL - ENGINE 1 AND 2, RELAY CHANGE (SHEET 4 OF 5) BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1 August 04, 2011 34 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 35 MORE DATAQTYIDENTIFICATIONNAMETASKSTEP below the new relay. Refer to SOPM 20-50-05, as an accept- ed procedure. 1BACT19J2I.D. TapeInstall (New)19 to the I.D. Tape. Refer to SOPM 20-50-10, as an accept- ed procedure. 1R8966Relay NumberApply20 The wires that are disconnected to remove the relay socket will not be put back into the new relay socket at this time. These wires are changed in a separate figure in this service bulletin. (a) The fasteners necessary to install the relay socket and the relay are provided with the new relay socket. Refer to SWPM 20-81-22, as an accepted procedure. (b) FIGURE 1: P252 PANEL - THRUST REVERSER CONTROL - ENGINE 1 AND 2, RELAY CHANGE (SHEET 5 OF 5) BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1 August 04, 2011 35 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 36 (OCR) BOEING SERVICE BULLETIN 747-78-2178 (2 LOCATIONS) W2281 4/008-20+A NC (6 LOCATIONS) GDX2-S Z8 1I12/124-20 30 098-20 -123-20x B2 -122-20 B1 22 069-20 Z1 +138-382X2 33 - 067-20-0 DR1269 R1269 RLY- T/R BRAKE (5 LOCATIONS) 2 REL ENG 1 35 / 022-20. 1 SEC AFTER STOWED ВЗ P D17821 J M10071 099-20 B2 147-20 B1 TD17 - 020-20-2 C1 P D17820J GDX2-S 'I|L 148-20 D 149-20 Х1 GDX1-DC " I|L 150-20 ‚Х2 UNSTOWED >DR8965 R8965 RLY- T/R UNSTOWED ENG 1 GDX1-DC •I|L 151-20 В3 GDX2-S "IID- 815-22- 015-22-0 B2 B1 017-22- DR8021 R8021 RLY- T/R UNSTOWED ENG 1 • 011-22 Х1 009-20 A1 -010-20 A2 DR8685 R8685 RLY- T/R GND SAFETY P252 PNL- LEFT THRUST REVERSER RELAY STA 350, WL 148, LBL 71 REFERENCE: 747 WIRING DIAGRAM 78-34-12 ADDED WIRE OR NEW ROUTING +/ DELETED WIRE OR FORMER ROUTING EXISTING WIRE The flag note numbers shown below agree with the numbers shown in the flag symbols in the figure. The parts necessary to do this figure are found in wire kit 61B20562-101 and Top Kit 015U1820-3. FIGURE 2: P252 PANEL - THRUST REVERSER CONTROL - ENGINE 1, W2281 WIRING CHANGE (SHEET 1 OF 2) Original Issue: January 22, 2009 Revision 1 August 04, 2011 BOEING PROPRIETARY - 747-78-2178 Copyright © Unpublished Work - See page 1 for details. 36 of 52 ### Page 37 MORE DATAQTYIDENTIFICATIONNAMEFLAG NOTE Refer to SWPM 20-61-11, as an ac- cepted procedure. 2BACC47CP1CONTACT, SOCKET1 Refer to SWPM 20-81-12, as an ac- cepted procedure. 6BACC47DJ1CONTACT, SOCKET2 Refer to SWPM 20-90-15, as an ac- cepted procedure. 3S280W555-920CONTACT3 -2BACS13CT2CSLEEVE, SOLDER4 -1BACS13CT3NSLEEVE, SOLDER5 Refer to SWPM 20-90-11, as an ac- cepted procedure. 6M39029/11-145CONTACT, PIN6 DR8965 M/W R8965161B20562-10101I.D. TAPE7 BMS 13-54, Color White. Operator can use an equivalent material. Refer to SWPM 20-10-19, as an accepted procedure. -289T9001-91LACING TAPE8 WIRE INFORMATION TABLE FOR 61B20562-101W CUT LENGTH (inches)TYPE CODEMATERIAL SPECIFICATIONWIRE NUMBER 24PABMS 13-48, TYPE 10, CLASS 1, AWG 20W2281-098-20 30PABMS 13-48, TYPE 10, CLASS 1, AWG 20W2281-099-20 24PQBMS 13-48, TYPE 3, CLASS 1, AWG 20W2281-147-20 24PABMS 13-48, TYPE 10, CLASS 1, AWG 20W2281-148-20 24PABMS 13-48, TYPE 10, CLASS 1, AWG 20W2281-149-20 24PABMS 13-48, TYPE 10, CLASS 1, AWG 20W2281-150-20 24PABMS 13-48, TYPE 10, CLASS 1, AWG 20W2281-151-20 FIGURE 2: P252 PANEL - THRUST REVERSER CONTROL - ENGINE 1, W2281 WIRING CHANGE (SHEET 2 OF 2) BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1 August 04, 2011 37 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 38 (OCR) BOEING SERVICE BULLETIN 747-78-2178 (2 LOCATIONS) W2283 ฿ Y/008-20+A NC 6 LOCATIONS) GDX4-S 30 098-20 Z8 1114/124-20- 71117 -123-20g -122-207 B2 B1 22 069-20 Z1 +138-382X2 33 - 067-20-0 DR1270 R1270 RLY- T/R BRAKE (5 LOCATIONS) 2 REL ENG 2 ¢КẬ/ 1 SEC AFTER 3571/022-20 STOWED ВЗ P D17824J M10072 099-20 B2 147-20 B1 - 020-20-9 TD18 C1 P D17823J GDX4-S 'I|L 148-20 D 1149-20 Х1 GDX3-DC •I|D 150-20 ‚Х2 UNSTOWED >DR8966 R8966 RLY- T/R UNSTOWED ENG 2 GDX3-DC•IID 151-20 В3 015-22-9 1 B2 GDX4-S "IID- 815-22- B1 017-22- DR8022 R8022 RLY- T/R UNSTOWED ENG 2 •011-22 009-20 A1 -010-20 A2 DR8686 R8686 RLY- T/R GND SAFETY P252 PNL- LEFT THRUST REVERSER RELAY STA 350, WL 148, LBL 71 REFERENCE: 747 WIRING DIAGRAM 78-34-22 ADDED WIRE OR NEW ROUTING +/ DELETED WIRE OR FORMER ROUTING EXISTING WIRE The flag note numbers shown below agree with the numbers shown in the flag symbols in the figure. The parts necessary to do this figure are found in wire kit 61B20562-102 and Top Kit 015U1820-3. FIGURE 3: P252 PANEL - THRUST REVERSER CONTROL - ENGINE 2, W2283 WIRING CHANGE (SHEET 1 OF 2) Original Issue: January 22, 2009 Revision 1 August 04, 2011 BOEING PROPRIETARY - 747-78-2178 Copyright © Unpublished Work - See page 1 for details. 38 of 52 ### Page 39 MORE DATAQTYIDENTIFICATIONNAMEFLAG NOTE Refer to SWPM 20-61-11, as an ac- cepted procedure. 2BACC47CP1CONTACT, SOCKET1 Refer to SWPM 20-81-12, as an ac- cepted procedure. 6BACC47DJ1CONTACT, SOCKET2 Refer to SWPM 20-90-15, as an ac- cepted procedure. 3S280W555-920CONTACT3 -2BACS13CT2CSLEEVE, SOLDER4 -1BACS13CT3NSLEEVE, SOLDER5 Refer to SWPM 20-90-11, as an ac- cepted procedure. 6M39029/11-145CONTACT, PIN6 DR8966 M/W R8966161B20562-10201I.D. TAPE7 BMS 13-54, Color White. Operators can use an equivalent material. Refer to SWPM 20-10-19, as an accepted procedure. -289T9001-91LACING TAPE8 WIRE INFORMATION TABLE FOR 61B20562-102W CUT LENGTH (inches)TYPE CODEMATERIAL SPECIFICATIONWIRE NUMBER 24PABMS 13-48, TYPE 10, CLASS 1, AWG 20W2283-098-20 30PABMS 13-48, TYPE 10, CLASS 1, AWG 20W2283-099-20 24PQBMS 13-48, TYPE 3, CLASS 1, AWG 20W2283-147-20 24PABMS 13-48, TYPE 10, CLASS 1, AWG 20W2283-148-20 24PABMS 13-48, TYPE 10, CLASS 1, AWG 20W2283-149-20 24PABMS 13-48, TYPE 10, CLASS 1, AWG 20W2283-150-20 24PABMS 13-48, TYPE 10, CLASS 1, AWG 20W2283-151-20 FIGURE 3: P252 PANEL - THRUST REVERSER CONTROL - ENGINE 2, W2283 WIRING CHANGE (SHEET 2 OF 2) BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1 August 04, 2011 39 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 40 (OCR) BOEING SERVICE BULLETIN 747-78-2178 SEE A 2 8 LOCATIONS • FWD P252 PANEL LEFT THRUST REVERSER RELAY The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for each airplane. FIGURE 4: P252 PANEL - THRUST REVERSER CONTROL - ENGINE 1 AND ENGINE 2, RETURN ACCESS (SHEET 1 OF 2) Original Issue: January 22, 2009 Revision 1 August 04, 2011 BOEING PROPRIETARY - 747-78-2178 Copyright © Unpublished Work - See page 1 for details. 40 of 52 ### Page 41 MORE DATAQTYIDENTIFICATIONNAMETASKSTEP back to their initial position.2-Panel AssemblyPut1 -8-ScrewsInstall (Kept)2 -1-P252 Panel DoorClose3 FIGURE 4: P252 PANEL - THRUST REVERSER CONTROL - ENGINE 1 AND ENGINE 2, RETURN ACCESS (SHEET 2 OF 2) BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1 August 04, 2011 41 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 42 (OCR) BOEING SERVICE BULLETIN 747-78-2178 P253 PANEL SEE FWD P253 PANEL RIGHT THRUST REVERSER RELAY 1345958 FIGURE 5: P253 PANEL - THRUST REVERSER CONTROL - ENGINE 3 AND 4, RELAY CHANGE (SHEET 1 OF 5) Original Issue: January 22, 2009 Revision 1 August 04, 2011 BOEING PROPRIETARY - 747-78-2178 Copyright © Unpublished Work - See page 1 for details. 42 of 52 ### Page 43 (OCR) BOEING SERVICE BULLETIN 747-78-2178 SEE 20 1217 FWDS P253 PANEL RIGHT THRUST REVERSER RELAY A-A 1346002 FIGURE 5: P253 PANEL - THRUST REVERSER CONTROL - ENGINE 3 AND 4, RELAY CHANGE (SHEET 2 OF 5) Original Issue: January 22, 2009 Revision 1 August 04, 2011 747-78-2178 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 43 of 52 ### Page 44 (OCR) BOEING SERVICE BULLETIN 747-78-2178 FWDS P253 PANEL RIGHT THRUST REVERSER RELAY 1346042 FIGURE 5: P253 PANEL - THRUST REVERSER CONTROL - ENGINE 3 AND 4, RELAY CHANGE (SHEET 3 OF 5) Original Issue: January 22, 2009 Revision 1 August 04, 2011 BOEING PROPRIETARY - 747-78-2178 Copyright © Unpublished Work - See page 1 for details. 44 of 52 ### Page 45 The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for each airplane. The parts necessary to do this figure are found in Top Kit 015U1820-3, wire kit 61B20562-103 and wire kit 61B20562-104. NOTE: The relay panel assemblies that hold the relays must not be installed when this figure is completed, because there are wiring changes done behind these panels. The return access to the P253 Panel will do this work in a separate figure. MORE DATAQTYIDENTIFICATIONNAMETASKSTEP -1-P253 PanelAccess1 -1-P253 Panel DoorOpen2 -1-Relay (R1271)Remove3 -4-ScrewsRemove/Keep4 to get access to remove the relay socket. Support the re- lay panel as necessary to not put strain on the wire bundle. 1-Panel AssemblyMove5 (a)1-Relay SocketRemove6 (a) (b)1BACS16W5ARelay SocketInstall (New)7 (b)1TDH-8120-1001Relay (R8967)Install (New)8 with relay number R1271.1-I.D. TapeRemove9 below the new relay. Refer to SOPM 20-50-05 1BACT19J2I.D. TapeInstall (New)10 to the I.D. Tape. Refer to SOPM 20-50-10, as an ac- cepted procedure. 1R8967Relay NumberApply11 -1-Relay (R1272)Remove12 -4-ScrewsRemove/Keep13 to get access to remove a re- lay socket. Support the relay panel as necessary to not put strain on the wire bundle. 1-Panel AssemblyMove14 (a)1-Relay SocketRemove15 (a) (b)1BACS16W5ARelay SocketInstall (New)16 (b)1TDH-8120-1001Relay (R8968)Install (New)17 with relay number R1272.1-I.D. TapeRemove18 below the new relay. Refer to SOPM 20-50-05, as an ac- cepted procedure. 1BACT19J2I.D. TapeInstall (New)19 FIGURE 5: P253 PANEL - THRUST REVERSER CONTROL - ENGINE 3 AND 4, RELAY CHANGE (SHEET 4 OF 5) BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1 August 04, 2011 45 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 46 MORE DATAQTYIDENTIFICATIONNAMETASKSTEP to the I.D. Tape. Refer to SOPM 20-50-10, as an ac- cepted procedure. 1R8968Relay NumberApply20 The wires that are disconnected to remove the relay socket will not be put back into the new relay socket at this time. These wires are changed in a separate figure in this service bulletin. (a) The fasteners necessary to install the relay socket and the relay are provided with the new relay socket. Refer to SWPM 20-81-22, as an accepted procedure. (b) FIGURE 5: P253 PANEL - THRUST REVERSER CONTROL - ENGINE 3 AND 4, RELAY CHANGE (SHEET 5 OF 5) BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1 August 04, 2011 46 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 47 (OCR) BOEING SERVICE BULLETIN 747-78-2178 (2 LOCATIONS) W2285 47008-20+1 NC - 6 LOCATIONS) GDX2-S Z8 1112/124-207 30 098-20 7777 7123-20 - 123-209 B2 B1 22 069-20 Z1 4128-38-0x2 33 • 067-20 2 DR1271 R1271 RLY- T/R BRAKE (5 LOCATIONS) REL ENG 3 35 /// 022-20. F 13 STOWED 1 SEC AFTER D17827 J M10073 1099-20 B2 147-20 B1 TD19 - 020-20-2 C1 P D17826J GDX2-S "I|L •148-20• •149-20 GDX1-DC •I|D 150-20 X2 UNSTOWED -DR8967 R8967 RLY- T/R UNSTOWED ENG 3 GDX1-DC •I|[ 1151-20 015-22-0 B2 GDX2-S 1110- B1 017-22- DR8023 R8023 RLY- T/R UNSTOWED ENG 3 - 011-22 X1 • 009-20 A1 -010-20 A2 DR8687 R8687 RLY- T/R GND SAFETY P253 PNL- RIGHT THRUST REVERSER RELAY STA 350, WL 148, RBL 71 REFERENCE: 747 WIRING DIAGRAM 78-34-32 • ADDED WIRE OR NEW ROUTING + DELETED WIRE OR FORMER ROUTING - EXISTING WIRE The flag note numbers shown below agree with the numbers shown in the flag symbols in the figure. The parts necessary to do this figure are found in wire kit 61B20562-103 and Top Kit 015U1820-3. FIGURE 6: P253 PANEL - THRUST REVERSER CONTROL - ENGINE 3, W2285 WIRING CHANGE (SHEET 1 OF 2) Original Issue: January 22, 2009 Revision 1 August 04, 2011 747-78-2178 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 47 of 52 ### Page 48 MORE DATAQTYIDENTIFICATIONNAMEFLAG NOTE Refer to SWPM 20-61-11, as an accept- ed procedure. 2BACC47CP1CONTACT, SOCKET1 Refer to SWPM 20-81-12, as an accept- ed procedure. 6BACC47DJ1CONTACT, SOCKET2 Refer to SWPM 20-90-15, as an accept- ed procedure. 3S280W555-920CONTACT3 -2BACS13CT2CSLEEVE, SOLDER4 -1BACS13CT3NSLEEVE, SOLDER5 Refer to SWPM 20-90-11, as an accept- ed procedure. 6M39029/11-145CONTACT, PIN6 DR8967 M/W R8967161B20562-10301I.D. TAPE7 BMS 13-54, Color White. Operator can use an equivalent material. Refer to SWPM 20-10-19, as an accepted pro- cedure. -289T9001-91LACING TAPE8 WIRE INFORMATION TABLE FOR 61B20562-103W CUT LENGTH (inches)TYPE CODEMATERIAL SPECIFICATIONWIRE NUMBER 24PABMS 13-48, TYPE 10, CLASS 1, AWG 20W2285-098-20 30PABMS 13-48, TYPE 10, CLASS 1, AWG 20W2285-099-20 24PQBMS 13-48, TYPE 3, CLASS 1, AWG 20W2285-147-20 24PABMS 13-48, TYPE 10, CLASS 1, AWG 20W2285-148-20 24PABMS 13-48, TYPE 10, CLASS 1, AWG 20W2285-149-20 24PABMS 13-48, TYPE 10, CLASS 1, AWG 20W2285-150-20 24PABMS 13-48, TYPE 10, CLASS 1, AWG 20W2285-151-20 FIGURE 6: P253 PANEL - THRUST REVERSER CONTROL - ENGINE 3, W2285 WIRING CHANGE (SHEET 2 OF 2) BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1 August 04, 2011 48 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 49 (OCR) BOEING SERVICE BULLETIN 747-78-2178 (2 LOCATIONS) W22871 47008-20+4 NC - LOCATIONS) GDX4-S Z8 1II4/124-20- 30 098-20 H/ 123-20- B2 7777 -122-207 B1 22 069-20 Z1 4128-380x2 33 • 067-20 2 DR1272 R1272 RLY- T/R BRAKE (5 LOCATIONS) REL ENG 4 35 1/022-20. 1 SEC AFTER STOWED D17830J M10074 099-20 B2 147-20 B1 TD20 - 020-20-Q C1 P D17829J GDX4-S 'I|L •148-20• •149-20 GDX3-DC •I|D • 150-20 X2 UNSTOWED -DR8968 R8968 RLY- T/R UNSTOWED ENG 4 GDX3-DC•I| 151-20 015-22-9 B2 GDX4-S "II0 B1 017-22- DR8024 R8024 RLY- T/R UNSTOWED ENG 4 -011-22 • 009-20 A1 010-20 A2 DR8688 R8688 RLY- T/R GND SAFETY P253 PNL- RIGHT THRUST REVERSER RELAY STA 350, WL 148, RBL 71 REFERENCE: 747 WIRING DIAGRAM 78-34-42 - ADDED WIRE OR NEW ROUTING + DELETED WIRE OR FORMER ROUTING - EXISTING WIRE The flag note numbers shown below agree with the numbers shown in the flag symbols in the figure. The parts necessary to do this figure are found in wire kit 61B20562-104 and Top Kit 015U1820-3. FIGURE 7: P253 PANEL - THRUST REVERSER CONTROL - ENGINE 4, W2287 WIRING CHANGE (SHEET 1 OF 2) Original Issue: January 22, 2009 Revision 1 August 04, 2011 747-78-2178 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 49 of 52 ### Page 50 MORE DATAQTYIDENTIFICATIONNAMEFLAG NOTE Refer to SWPM 20-61-11, as an accept- ed procedure. 2BACC47CP1CONTACT, SOCKET1 Refer to SWPM 20-81-12, as an accept- ed procedure. 6BACC47DJ1CONTACT, SOCKET2 Refer to SWPM 20-90-15, as an accept- ed procedure. 3S280W555-920CONTACT3 -2BACS13CT2CSLEEVE, SOLDER4 -1BACS13CT3NSLEEVE, SOLDER5 Refer to SWPM 20-90-11, as an accept- ed procedure. 6M39029/11-145CONTACT, PIN6 DR8968 M/W R8968161B20562-10401I.D. TAPE7 BMS 13-54, Color White. Operator can use an equivalent material. Refer to SWPM 20-10-19, as an accepted proce- dure. -289T9001-91LACING TAPE8 WIRE INFORMATION TABLE FOR 61B20562-104W CUT LENGTH (inches)TYPE CODEMATERIAL SPECIFICATIONWIRE NUMBER 24PABMS 13-48, TYPE 10, CLASS 1, AWG 20W2287-098-20 30PABMS 13-48, TYPE 10, CLASS 1, AWG 20W2287-099-20 24PQBMS 13-48, TYPE 3, CLASS 1, AWG 20W2287-147-20 24PABMS 13-48, TYPE 10, CLASS 1, AWG 20W2287-148-20 24PABMS 13-48, TYPE 10, CLASS 1, AWG 20W2287-149-20 24PABMS 13-48, TYPE 10, CLASS 1, AWG 20W2287-150-20 24PABMS 13-48, TYPE 10, CLASS 1, AWG 20W2287-151-20 FIGURE 7: P253 PANEL - THRUST REVERSER CONTROL - ENGINE 4, W2287 WIRING CHANGE (SHEET 2 OF 2) BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1 August 04, 2011 50 of 52 BOEING SERVICE BULLETIN 747-78-2178 ### Page 51 (OCR) BOEING SERVICE BULLETIN 747-78-2178 SEE A 8 LOCATIONS 2 FWD P253 PANEL RIGHT THRUST REVERSER RELAY 1346188 The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for each airplane. FIGURE 8: P253 PANEL - THRUST REVERSER CONTROL - ENGINE 3 AND ENGINE 4, RETURN ACCESS (SHEET 1 OF 2) Original Issue: January 22, 2009 Revision 1 August 04, 2011 747-78-2178 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 51 of 52 ### Page 52 MORE DATAQTYIDENTIFICATIONNAMETASKSTEP back to their initial position.2-Panel AssemblyPut1 -8-ScrewsInstall (Kept)2 -1-P253 Panel DoorClose3 FIGURE 8: P253 PANEL - THRUST REVERSER CONTROL - ENGINE 3 AND ENGINE 4, RETURN ACCESS (SHEET 2 OF 2) BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: January 22, 2009 747-78-2178Revision 1 August 04, 2011 52 of 52 BOEING SERVICE BULLETIN 747-78-2178 --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. 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