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.

ECCN: 9E991

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Unpublished Work - All Rights Reserved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,

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3.0
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BOEING SERVICE BULLETIN 747-78-2178

BLANK PAGE
Table of Contents

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

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

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

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

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

2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

B. Concurrent Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

C. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

E. Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

H. Weight and Balance Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

1. Existing Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

2. Data supplied with this Service Bulletin: . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

3. Installation Drawings Used in the Preparation of this Service Bulletin: . . . . . . . . . . . 13

K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

2. MATERIAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

A. Material - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

C. Parts Necessary For Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

1. Kits/Parts: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

2. Parts and Materials Supplied by the Operator: . . . . . . . . . . . . . . . . . . . . . . . . 17

3. Parts Modified and Reidentified: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

4. Parts Removed and Not Replaced: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

D. Parts Necessary to Change Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

E. Special Tooling - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

F. Special Tooling Necessary to do this Service Bulletin . . . . . . . . . . . . . . . . . . . . . . . 17

3. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

B. WORK INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

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BOEING SERVICE BULLETIN 747-78-2178
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BOEING SERVICE BULLETIN 747-78-2178

BLANK PAGE
Commercial 

Airplanes 747

Service Bulletin

Revision Transmittal Sheet 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

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.

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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

Original Issue: January 22, 2009

Revision 1: August 04, 2011

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BOEING SERVICE BULLETIN 747-78-2178
Commercial 

Airplanes 747

Service Bulletin

Summary 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

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.

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7 of 52
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

Airplanes Total Task Hours Elapsed Hours

Group 1 30 25

MATERIAL INFORMATION

Boeing Supplied Kits/Parts.

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

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BOEING SERVICE BULLETIN 747-78-2178
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.

GROUP CONFIGURATION DESCRIPTION

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

Variable Number Group

RB411 - RB413 1

RD131 - RD132 1

RD135 - RD138 1

RD141 - RD144 1

RD311 1

RD356 - RD358 1

RD471 - RD475 1

RH101 - RH102 1

RR441 - RR442 1

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Variable Number Group

RR526 1

RR531 1

RS271 - RS276 1

RS301 - RS306 1

RS311 - RS320 1

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:

Company Service Bulletin Description

Gives the instruction to install an additional

locking system on the thrust reversers.

Boeing 747-78-2156, Original Issue or Revision 1

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.

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BOEING SERVICE BULLETIN 747-78-2178
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

Model Zone

747-200B, 747-200F, 747-300, 115, 116, 117, 118

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.

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BOEING SERVICE BULLETIN 747-78-2178
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.

Number of Per- Task-Hours Elapsed Hours

sons

Task

Open Access 1 0.25 0.25

Figure 1 1 1.0 1.0

Figure 2 1 4.25 4.25

Figure 3 1 4.25 4.25

Figure 4 1 0.25 0.25

Figure 5 1 1.0 1.0

Figure 6 1 4.25 4.25

Figure 7 1 4.25 4.25

Figure 8 1 0.25 0.25

Close Access 1 0.25 0.25

Continuity Checks and 2 10 5

Functional Tests

TOTAL FOR EACH AIRPLANE 30 25

H. Weight and Balance Changes

Change in Moment

(Pound-Inches)

Change in Weight

(Pounds)

Airplane

747-200, 747-300 +0.9 +315.0

747 SP +0.9 +495.0

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BOEING SERVICE BULLETIN 747-78-2178
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:

Publication Chapter-Section

747 Wiring Diagram Manual 78-34-12, 78-34-22, 78-34-32, 78-34-42

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.

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BOEING SERVICE BULLETIN 747-78-2178
Publication Chapter-Section

747 Wiring Diagram Manual 78-34-12, 78-34-22, 78-34-32, 78-34-42

L. Interchangeability and Intermixability of Parts

Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts.

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BOEING SERVICE BULLETIN 747-78-2178
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)

Kit Number Name Date QTY

015U1820-3 Top Kit November 8, 2007 1 22 $4,289

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

New Part Number QTY Name Notes

-3

TOP KIT - RR Powered 747 Uncommanded Thrust Reverser

Unlock Events

015U1820-3 -

289T9001-91 1 LACING TAPE - WHITE (135C) 100 FT

ROLLS ROYCE POWERED 747 UNCOMMANDED THRUST

REVERSER UNLOCK ENG 1 (W2281)

61B20562-101 1

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BOEING SERVICE BULLETIN 747-78-2178
Kit 015U1820-3

New Part Number QTY Name Notes

-3

ROLLS ROYCE POWERED 747 UNCOMMANDED THRUST

REVERSER UNLOCK ENG 2 (W2283)

61B20562-102 1

ROLLS ROYCE POWERED 747 UNCOMMANDED THRUST

REVERSER UNLOCK ENG 3 (W2285)

61B20562-103 1

ROLLS ROYCE POWERED 747 UNCOMMANDED THRUST

REVERSER UNLOCK ENG 4 (W2287)

61B20562-104 1

BACT19J2 4 TAPE, ID

TDH-8120-1001 4 TIME DELAY RELAY

Wire Kit 61B20562

New Part Number QTY Name Notes

-104 -103 -102 -101

WIRE KIT - ROLLS ROYCE POWERED 747 UNCOMMANDED THRUST REVERSER UNLOCK ENG

1 (W2281)

61B20562-101 . . . -

WIRE KIT - ROLLS ROYCE POWERED 747 UNCOMMANDED THRUST REVERSER UNLOCK ENG

2 (W2283)

61B20562-102 . . - .

WIRE KIT - ROLLS ROYCE POWERED 747 UNCOMMANDED THRUST REVERSER UNLOCK ENG

3 (W2285)

61B20562-103 . - . .

WIRE KIT - ROLLS ROYCE POWERED 747 UNCOMMANDED THRUST REVERSER UNLOCK ENG

4 (W2287)

61B20562-104 - . . .

61B20562-101W . . . 1 WIRE CUT & CODE

61B20562-102W . . 1 . WIRE CUT & CODE

61B20562-103W . 1 . . WIRE CUT & CODE

61B20562-104W 1 . . . WIRE CUT & CODE

61B20562-10101 . . . 1 I.D. TAPE

61B20562-10201 . . 1 . I.D. TAPE

61B20562-10301 . 1 . . I.D. TAPE

61B20562-10401 1 . . . I.D. TAPE

BACC47CP1 3 3 3 3 CONTACT, SOCKET (a)

M39029/11-145 7 7 7 7 CONTACT, PIN (a)

BACC47DJ1 7 7 7 7 CONTACT, SOCKET (a)

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BOEING SERVICE BULLETIN 747-78-2178
Wire Kit 61B20562

New Part Number QTY Name Notes

-104 -103 -102 -101

BACS13CT2C 3 3 3 3 SLEEVE, SOLDER (HEAT SHRINK) (a)

BACS13CT3N 2 2 2 2 SLEEVE, SOLDER (HEAT SHRINK) (a)

BACS16W5A 1 1 1 1 RELAY SOCKET

S280W555-920 4 4 4 4 CONTACT, PIN, SIZE 20 (a)

(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.

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BOEING SERVICE BULLETIN 747-78-2178

BLANK PAGE
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.

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B. WORK INSTRUCTIONS

1. Open these circuit breakers on the P6 and P12 panels. Install safety tags.

P6 Main Power Distribution Panel

Circuit Breaker Number Name

C10934 T/R LOCK CONT ENG 1

C10935 T/R LOCK CONT ENG 2

P12 Overhead Circuit Breaker Panel

Circuit Breaker Number Name

C00405 T/R IND ENG 1

C01703 T/R CONT ENG 1

C00402 T/R IND ENG 2

C01704 T/R CONT ENG 2

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

Circuit Breaker Number Name

C10936 T/R LOCK CONT ENG 3

C10937 T/R LOCK CONT ENG 4

P12 Overhead Circuit Breaker Panel

Circuit Breaker Number Name

C00403 T/R IND ENG 3

C01442 T/R CONT ENG 3

C00404 T/R IND ENG 4

C01441 T/R CONT ENG 4

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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

Circuit Breaker Number Name

C10934 T/R LOCK CONT ENG 1

C10935 T/R LOCK CONT ENG 2

C10936 T/R LOCK CONT ENG 3

C10937 T/R LOCK CONT ENG 4

P12 Overhead Circuit Breaker Panel

Circuit Breaker Number Name

C00405 T/R IND ENG 1

C01703 T/R CONT ENG 1

C00402 T/R IND ENG 2

C01704 T/R CONT ENG 2

C00403 T/R IND ENG 3

C01442 T/R CONT ENG 3

C00404 T/R IND ENG 4

C01441 T/R CONT ENG 4

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.

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P6 Main Power Distribution Panel

Circuit Breaker Number Name

C10934 T/R LOCK CONT ENG 1

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.

FROM Pin # TO Pin #

D17821J 33 D17820 17

D17821J 33 DR8965 B1

D17821J 6 DR8965 B2

DR8021 B2 DR8965 C1

D17821J 30 DR8965 X1

D17821J 30 DR8685 A2

D17821J 30 DR8021 B1

D17821J 30 DR8021 X1

D17821J 22 DR8685 X1

D17821J 22 DR8685 A1

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.

FROM Pin # TO Pin #

D17821J 33 DR8021 B2

D17821J 6 DR8021 B1

D17821J 22 DR8021 X1

DR8685 X1 DR8021 X1

DR8965 A1 DR8021 X1

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.

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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

Circuit Breaker Number Name

C10934 T/R LOCK CONT ENG 1

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

Circuit Breaker Number Name

C10934 T/R LOCK CONT ENG 1

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.

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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

Circuit Breaker Number Name

C10935 T/R LOCK CONT ENG 2

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.

FROM Pin # TO Pin #

D17824J 33 D17823 17

D17824J 33 DR8966 B1

D17824J 6 DR8966 B2

DR8022 B2 DR8966 C1

D17824J 30 DR8966 X1

D17824J 30 DR8686 A2

D17824J 30 DR8022 B1

D17824J 30 DR8022 X1

D17824J 22 DR8686 X1

D17824J 22 DR8686 A1

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.

FROM Pin # TO Pin #

D17824J 33 DR8022 B2

D17824J 6 DR8022 B1

D17824J 22 DR8022 X1

DR8686 X1 DR8022 X1

DR8966 A1 DR8022 X1

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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

Circuit Breaker Number Name

C10935 T/R LOCK CONT ENG 2

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

Circuit Breaker Number Name

C10935 T/R LOCK CONT ENG 2

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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

Circuit Breaker Number Name

C10936 T/R LOCK CONT ENG 3

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.

FROM Pin # TO Pin #

D17827J 33 D17826 17

D17827J 33 DR8967 B1

D17827J 6 DR8967 B2

DR8023 B2 DR8967 C1

D17827J 30 DR8967 X1

D17827J 30 DR8687 A2

D17827J 30 DR8023 B1

D17827J 30 DR8023 X1

D17827J 22 DR8687 X1

D17827J 22 DR8687 A1

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.

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FROM Pin # TO Pin #

D17827J 33 DR8023 B2

D17827J 6 DR8023 B1

D17827J 22 DR8023 X1

DR8687 X1 DR8023 X1

DR8967 A1 DR8023 X1

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

Circuit Breaker Number Name

C10936 T/R LOCK CONT ENG 3

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:

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BOEING SERVICE BULLETIN 747-78-2178
(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

Circuit Breaker Number Name

C10936 T/R LOCK CONT ENG 3

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

Circuit Breaker Number Name

C10937 T/R LOCK CONT ENG 4

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.

FROM Pin # TO Pin #

D17830J 33 D17829 17

D17830J 33 DR8968 B1

D17830J 6 DR8968 B2

DR8024 B2 DR8968 C1

D17830J 30 DR8968 X1

D17830J 30 DR8688 A2

D17830J 30 DR8024 B1

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FROM Pin # TO Pin #

D17830J 30 DR8024 X1

D17830J 22 DR8688 X1

D17830J 22 DR8688 A1

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.

FROM Pin # TO Pin #

D17830J 33 DR8024 B2

D17830J 6 DR8024 B1

D17830J 22 DR8024 X1

DR8688 X1 DR8024 X1

DR8968 A1 DR8024 X1

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

Circuit Breaker Number Name

C10937 T/R LOCK CONT ENG 4

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.

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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

Circuit Breaker Number Name

C10937 T/R LOCK CONT ENG 4

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.

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FIGURE 1: P252 PANEL - THRUST REVERSER CONTROL - ENGINE 1 AND 2, RELAY CHANGE

(SHEET 1 OF 5)

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BOEING SERVICE BULLETIN 747-78-2178
FIGURE 1: P252 PANEL - THRUST REVERSER CONTROL - ENGINE 1 AND 2, RELAY CHANGE

(SHEET 2 OF 5)

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BOEING SERVICE BULLETIN 747-78-2178
FIGURE 1: P252 PANEL - THRUST REVERSER CONTROL - ENGINE 1 AND 2, RELAY CHANGE

(SHEET 3 OF 5)

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

numbers shown below are the 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.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Access P252 Panel - 1 -

2 Open P252 Panel Door - 1 -

3 Remove Relay (R1269) - 1 -

4 Remove/Keep Screws - 4 -

to get access to remove the

relay socket. Support the relay

panel as necessary to not put

strain on the wire bundle.

5 Move Panel Assembly - 1

6 Remove Relay Socket - 1 (a)

7 Install (New) Relay Socket BACS16W5A 1 (a) (b)

8 Install (New) Relay (R8965) TDH-8120-1001 1 (b)

9 Remove I.D. Tape - 1 with relay number R1269.

below the new relay. Refer to

SOPM 20-50-05, as an accepted procedure.

10 Install (New) I.D. Tape BACT19J2 1

to the I.D. Tape. Refer to

SOPM 20-50-10, as an accepted procedure.

11 Apply Relay Number R8965 1

12 Remove Relay (R1270) - 1 -

13 Remove/Keep Screws - 4 -

to get access to remove a relay

socket. Support the relay panel

as necessary to not put strain

on the wire bundle.

14 Move Panel Assembly - 1

15 Remove Relay Socket - 1 (a)

16 Install (New) Relay Socket BACS16W5A 1 (a) (b)

17 Install (New) Relay (R8966) TDH-8120-1001 1 (b)

18 Remove I.D. Tape - 1 with relay number R1270.

FIGURE 1: P252 PANEL - THRUST REVERSER CONTROL - ENGINE 1 AND 2, RELAY CHANGE

(SHEET 4 OF 5)

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34 of 52

BOEING SERVICE BULLETIN 747-78-2178
STEP TASK NAME IDENTIFICATION QTY MORE DATA

below the new relay. Refer to

SOPM 20-50-05, as an accepted procedure.

19 Install (New) I.D. Tape BACT19J2 1

to the I.D. Tape. Refer to

SOPM 20-50-10, as an accepted procedure.

20 Apply Relay Number R8966 1

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

Revision 1 August 04, 2011 747-78-2178

35 of 52

BOEING SERVICE BULLETIN 747-78-2178
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)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: January 22, 2009

Revision 1 August 04, 2011 747-78-2178

36 of 52

BOEING SERVICE BULLETIN 747-78-2178
FLAG NAME IDENTIFICATION QTY MORE DATA

NOTE

Refer to SWPM 20-61-11, as an accepted procedure.1 CONTACT, SOCKET BACC47CP1 2

Refer to SWPM 20-81-12, as an accepted procedure.2 CONTACT, SOCKET BACC47DJ1 6

Refer to SWPM 20-90-15, as an accepted procedure.3 CONTACT S280W555-920 3

4 SLEEVE, SOLDER BACS13CT2C 2 -

5 SLEEVE, SOLDER BACS13CT3N 1 -

Refer to SWPM 20-90-11, as an accepted procedure.6 CONTACT, PIN M39029/11-145 6

7 I.D. TAPE 61B20562-10101 1 DR8965 M/W R8965

BMS 13-54, Color White. Operator

can use an equivalent material. Refer

to SWPM 20-10-19, as an accepted

procedure.

8 LACING TAPE 289T9001-91 -

WIRE INFORMATION TABLE FOR 61B20562-101W

WIRE NUMBER MATERIAL SPECIFICATION TYPE CODE CUT LENGTH (inches)

W2281-098-20 BMS 13-48, TYPE 10, CLASS 1, AWG 20 PA 24

W2281-099-20 BMS 13-48, TYPE 10, CLASS 1, AWG 20 PA 30

W2281-147-20 BMS 13-48, TYPE 3, CLASS 1, AWG 20 PQ 24

W2281-148-20 BMS 13-48, TYPE 10, CLASS 1, AWG 20 PA 24

W2281-149-20 BMS 13-48, TYPE 10, CLASS 1, AWG 20 PA 24

W2281-150-20 BMS 13-48, TYPE 10, CLASS 1, AWG 20 PA 24

W2281-151-20 BMS 13-48, TYPE 10, CLASS 1, AWG 20 PA 24

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

Revision 1 August 04, 2011 747-78-2178

37 of 52

BOEING SERVICE BULLETIN 747-78-2178
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)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: January 22, 2009

Revision 1 August 04, 2011 747-78-2178

38 of 52

BOEING SERVICE BULLETIN 747-78-2178
FLAG NAME IDENTIFICATION QTY MORE DATA

NOTE

Refer to SWPM 20-61-11, as an accepted procedure.1 CONTACT, SOCKET BACC47CP1 2

Refer to SWPM 20-81-12, as an accepted procedure.2 CONTACT, SOCKET BACC47DJ1 6

Refer to SWPM 20-90-15, as an accepted procedure.3 CONTACT S280W555-920 3

4 SLEEVE, SOLDER BACS13CT2C 2 -

5 SLEEVE, SOLDER BACS13CT3N 1 -

Refer to SWPM 20-90-11, as an accepted procedure.6 CONTACT, PIN M39029/11-145 6

7 I.D. TAPE 61B20562-10201 1 DR8966 M/W R8966

BMS 13-54, Color White. Operators

can use an equivalent material. Refer

to SWPM 20-10-19, as an accepted

procedure.

8 LACING TAPE 289T9001-91 -

WIRE INFORMATION TABLE FOR 61B20562-102W

WIRE NUMBER MATERIAL SPECIFICATION TYPE CODE CUT LENGTH (inches)

W2283-098-20 BMS 13-48, TYPE 10, CLASS 1, AWG 20 PA 24

W2283-099-20 BMS 13-48, TYPE 10, CLASS 1, AWG 20 PA 30

W2283-147-20 BMS 13-48, TYPE 3, CLASS 1, AWG 20 PQ 24

W2283-148-20 BMS 13-48, TYPE 10, CLASS 1, AWG 20 PA 24

W2283-149-20 BMS 13-48, TYPE 10, CLASS 1, AWG 20 PA 24

W2283-150-20 BMS 13-48, TYPE 10, CLASS 1, AWG 20 PA 24

W2283-151-20 BMS 13-48, TYPE 10, CLASS 1, AWG 20 PA 24

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

Revision 1 August 04, 2011 747-78-2178

39 of 52

BOEING SERVICE BULLETIN 747-78-2178
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)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: January 22, 2009

Revision 1 August 04, 2011 747-78-2178

40 of 52

BOEING SERVICE BULLETIN 747-78-2178
STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Put Panel Assembly - 2 back to their initial position.

2 Install (Kept) Screws - 8 -

3 Close P252 Panel Door - 1 -

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

Revision 1 August 04, 2011 747-78-2178

41 of 52

BOEING SERVICE BULLETIN 747-78-2178
FIGURE 5: P253 PANEL - THRUST REVERSER CONTROL - ENGINE 3 AND 4, RELAY CHANGE

(SHEET 1 OF 5)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: January 22, 2009

Revision 1 August 04, 2011 747-78-2178

42 of 52

BOEING SERVICE BULLETIN 747-78-2178
FIGURE 5: P253 PANEL - THRUST REVERSER CONTROL - ENGINE 3 AND 4, RELAY CHANGE

(SHEET 2 OF 5)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: January 22, 2009

Revision 1 August 04, 2011 747-78-2178

43 of 52

BOEING SERVICE BULLETIN 747-78-2178
FIGURE 5: P253 PANEL - THRUST REVERSER CONTROL - ENGINE 3 AND 4, RELAY CHANGE

(SHEET 3 OF 5)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: January 22, 2009

Revision 1 August 04, 2011 747-78-2178

44 of 52

BOEING SERVICE BULLETIN 747-78-2178
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.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Access P253 Panel - 1 -

2 Open P253 Panel Door - 1 -

3 Remove Relay (R1271) - 1 -

4 Remove/Keep Screws - 4 -

to get access to remove the

relay socket. Support the relay panel as necessary to not

put strain on the wire bundle.

5 Move Panel Assembly - 1

6 Remove Relay Socket - 1 (a)

7 Install (New) Relay Socket BACS16W5A 1 (a) (b)

8 Install (New) Relay (R8967) TDH-8120-1001 1 (b)

9 Remove I.D. Tape - 1 with relay number R1271.

below the new relay. Refer to

SOPM 20-50-05

10 Install (New) I.D. Tape BACT19J2 1

to the I.D. Tape. Refer to

SOPM 20-50-10, as an accepted procedure.

11 Apply Relay Number R8967 1

12 Remove Relay (R1272) - 1 -

13 Remove/Keep Screws - 4 -

to get access to remove a relay socket. Support the relay

panel as necessary to not put

strain on the wire bundle.

14 Move Panel Assembly - 1

15 Remove Relay Socket - 1 (a)

16 Install (New) Relay Socket BACS16W5A 1 (a) (b)

17 Install (New) Relay (R8968) TDH-8120-1001 1 (b)

18 Remove I.D. Tape - 1 with relay number R1272.

below the new relay. Refer to

SOPM 20-50-05, as an accepted procedure.

19 Install (New) I.D. Tape BACT19J2 1

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

Revision 1 August 04, 2011 747-78-2178

45 of 52

BOEING SERVICE BULLETIN 747-78-2178
STEP TASK NAME IDENTIFICATION QTY MORE DATA

to the I.D. Tape. Refer to

SOPM 20-50-10, as an accepted procedure.

20 Apply Relay Number R8968 1

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

Revision 1 August 04, 2011 747-78-2178

46 of 52

BOEING SERVICE BULLETIN 747-78-2178
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)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: January 22, 2009

Revision 1 August 04, 2011 747-78-2178

47 of 52

BOEING SERVICE BULLETIN 747-78-2178
FLAG NAME IDENTIFICATION QTY MORE DATA

NOTE

Refer to SWPM 20-61-11, as an accepted procedure.1 CONTACT, SOCKET BACC47CP1 2

Refer to SWPM 20-81-12, as an accepted procedure.2 CONTACT, SOCKET BACC47DJ1 6

Refer to SWPM 20-90-15, as an accepted procedure.3 CONTACT S280W555-920 3

4 SLEEVE, SOLDER BACS13CT2C 2 -

5 SLEEVE, SOLDER BACS13CT3N 1 -

Refer to SWPM 20-90-11, as an accepted procedure.6 CONTACT, PIN M39029/11-145 6

7 I.D. TAPE 61B20562-10301 1 DR8967 M/W R8967

BMS 13-54, Color White. Operator can

use an equivalent material. Refer to

SWPM 20-10-19, as an accepted procedure.

8 LACING TAPE 289T9001-91 -

WIRE INFORMATION TABLE FOR 61B20562-103W

WIRE NUMBER MATERIAL SPECIFICATION TYPE CODE CUT LENGTH (inches)

W2285-098-20 BMS 13-48, TYPE 10, CLASS 1, AWG 20 PA 24

W2285-099-20 BMS 13-48, TYPE 10, CLASS 1, AWG 20 PA 30

W2285-147-20 BMS 13-48, TYPE 3, CLASS 1, AWG 20 PQ 24

W2285-148-20 BMS 13-48, TYPE 10, CLASS 1, AWG 20 PA 24

W2285-149-20 BMS 13-48, TYPE 10, CLASS 1, AWG 20 PA 24

W2285-150-20 BMS 13-48, TYPE 10, CLASS 1, AWG 20 PA 24

W2285-151-20 BMS 13-48, TYPE 10, CLASS 1, AWG 20 PA 24

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

Revision 1 August 04, 2011 747-78-2178

48 of 52

BOEING SERVICE BULLETIN 747-78-2178
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)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: January 22, 2009

Revision 1 August 04, 2011 747-78-2178

49 of 52

BOEING SERVICE BULLETIN 747-78-2178
FLAG NAME IDENTIFICATION QTY MORE DATA

NOTE

Refer to SWPM 20-61-11, as an accepted procedure.1 CONTACT, SOCKET BACC47CP1 2

Refer to SWPM 20-81-12, as an accepted procedure.2 CONTACT, SOCKET BACC47DJ1 6

Refer to SWPM 20-90-15, as an accepted procedure.3 CONTACT S280W555-920 3

4 SLEEVE, SOLDER BACS13CT2C 2 -

5 SLEEVE, SOLDER BACS13CT3N 1 -

Refer to SWPM 20-90-11, as an accepted procedure.6 CONTACT, PIN M39029/11-145 6

7 I.D. TAPE 61B20562-10401 1 DR8968 M/W R8968

BMS 13-54, Color White. Operator can

use an equivalent material. Refer to

SWPM 20-10-19, as an accepted procedure.

8 LACING TAPE 289T9001-91 -

WIRE INFORMATION TABLE FOR 61B20562-104W

WIRE NUMBER MATERIAL SPECIFICATION TYPE CODE CUT LENGTH (inches)

W2287-098-20 BMS 13-48, TYPE 10, CLASS 1, AWG 20 PA 24

W2287-099-20 BMS 13-48, TYPE 10, CLASS 1, AWG 20 PA 30

W2287-147-20 BMS 13-48, TYPE 3, CLASS 1, AWG 20 PQ 24

W2287-148-20 BMS 13-48, TYPE 10, CLASS 1, AWG 20 PA 24

W2287-149-20 BMS 13-48, TYPE 10, CLASS 1, AWG 20 PA 24

W2287-150-20 BMS 13-48, TYPE 10, CLASS 1, AWG 20 PA 24

W2287-151-20 BMS 13-48, TYPE 10, CLASS 1, AWG 20 PA 24

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

Revision 1 August 04, 2011 747-78-2178

50 of 52

BOEING SERVICE BULLETIN 747-78-2178
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)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: January 22, 2009

Revision 1 August 04, 2011 747-78-2178

51 of 52

BOEING SERVICE BULLETIN 747-78-2178
STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Put Panel Assembly - 2 back to their initial position.

2 Install (Kept) Screws - 8 -

3 Close P253 Panel Door - 1 -

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

Revision 1 August 04, 2011 747-78-2178

52 of 52

BOEING SERVICE BULLETIN 747-78-2178