Commercial 

Airplane

Group 777

Service Bulletin

ALERT

Number: 777-78A0070

Date: November 20, 2008

ATA System: 7831

SUBJECT: EXHAUST (GE90) - Thrust Reverser System - GE Scavenge Tube Interference with

Thrust Reverser Insulation Blanket Bolt - Replacement

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 © 2008 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Unpublished Work - All Rights Reserved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, MD-10, MD-11, MD-80, MD-88, MD-90, 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BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details.

November 20, 2008

777-78A0070

1 of 22

2.0
BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details.

November 20, 2008

777-78A0070

2 of 22

BOEING SERVICE BULLETIN 777-78A0070

ALERT ALERT

BLANK PAGE
Table of Contents

Summary ..................................................... 5

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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

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

I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

1. Existing Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

2. Data supplied with this Service Bulletin . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

3. Installation Drawings Used in the Preparation of this Service Bulletin . . . . . . . . . . . . 12

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

L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

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

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

B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

C. Parts Necessary For Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

1. Kits/Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

2. Parts and Materials Supplied by the Operator . . . . . . . . . . . . . . . . . . . . . . . . 16

3. Parts Modified and Reidentified . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

FIGURE 1: THRUST REVERSER - AFT COWL INSULATION BLANKET - FASTENER CHANGE . . . 20

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

November 20, 2008

777-78A0070

3 of 22

BOEING SERVICE BULLETIN 777-78A0070

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

November 20, 2008

777-78A0070

4 of 22

BOEING SERVICE BULLETIN 777-78A0070

ALERT ALERT

BLANK PAGE
Commercial 

Airplane

Group 777

Service Bulletin

ALERT

Summary Number: 777-78A0070

Date: November 20, 2008

ATA System: 7831

SUBJECT: EXHAUST (GE90) - Thrust Reverser System - GE Scavenge Tube Interference with

Thrust Reverser Insulation Blanket Bolt - Replacement

THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH

1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO

THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO

THE NEW OWNER.

CONCURRENT REQUIREMENTS

Refer to Paragraph 1.B., Concurrent Requirements.

BACKGROUND

Accomplishment of this service bulletin will prevent interference between an oil scavenge tube on the Turbine

Rear Frame (TRF) of the General Electric (GE) engine and an aft cowl insulation blanket bolt. This interference

can cause damage to the oil scavenge tube. This damage could result in a puncture in the oil scavenge tube.

A punctured oil scavenge tube would cause oil loss and could cause an in-flight shutdown of the engine.

Boeing determined that there was insufficient clearance between an oil scavenge tube on the GE engine and

an aft cowl insulation blanket bolt. This location could experience interference under flight loads. Damage to the

oil scavenge tube was confirmed at Boeing on non-delivered airplanes after flight. Several in-service airplanes

were also inspected. Many of the airplanes showed damage because of the interference condition.The damage

was limited to dents, gouges, or chafing. However, some of the damage that was found was outside of serviceable

limits. No oil tube punctures were found or reported.

This service bulletin provides instructions to replace the aft cowl insulation blanket fasteners at one location to

gain additional clearance from the oil scavenge tube and remove the possible interference condition.

There are two related vendor service bulletins. GE Service Bulletin 79-0017 provides instructions to inspect the

oil scavenge tube for damage and should be done concurrently with this service bulletin. GE Service Bulletin

79-0019 provides instructions to replace the oil scavenge tube with a new tube that will increase clearance with

the insulation blanket bolt.

Boeing Service Related Problem (SRP) 777-SRP-72-0032 is related to this service bulletin.

ACTION

Open the left thrust reverser. Remove the lower aft cowl insulation blanket. Change the fasteners at one location.

Install the removed insulation blanket. Close the thrust reverser.

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

November 20, 2008

777-78A0070

5 of 22
EFFECTIVITY

777-200LR and -300ER Airplanes with GE90-100 engines. 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.

Boeing recommends that the change given in this service bulletin be done within 180 days or 300 flight cycles

after the date on this service bulletin, whichever occurs later.

INDUSTRY SUPPORT INFORMATION

Boeing warranty remedies are not available for the changes given in this service bulletin.

MANPOWER

Engines Total Task Hours Elapsed Hours

Each Engine 2.50 2.50

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.

November 20, 2008

777-78A0070

6 of 22

BOEING SERVICE BULLETIN 777-78A0070

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

November 20, 2008

777-78A0070

7 of 22

BOEING SERVICE BULLETIN 777-78A0070

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

November 20, 2008

777-78A0070

8 of 22

BOEING SERVICE BULLETIN 777-78A0070

ALERT ALERT

BLANK PAGE
Commercial 

Airplane

Group 777

Service Bulletin

ALERT

Number: 777-78A0070

Date: November 20, 2008

ATA System: 7831

SUBJECT: EXHAUST (GE90) - Thrust Reverser System - GE Scavenge Tube Interference with

Thrust Reverser Insulation Blanket Bolt - Replacement

THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH

1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO

THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO

THE NEW OWNER.

1. PLANNING INFORMATION

A. Effectivity

1. Airplanes

This service bulletin is for the airplanes shown below.

Refer to Service Bulletin Index Document D624W001 Part 3 for Airplane Variable Number, Line

Number, and Serial Number data.

GROUP CONFIGURATION DESCRIPTION

1 - 777-200LR and -300ER Airplanes with GE90-100 Engines

Airplane Models:

777-200LR, 777-300ER

Variable Number Group

WD001 - WD002 1

WD011 - WD014 1

WD031 - WD033 1

WD046 - WD048 1

WD501 - WD507 1

WD521 - WD537 1

WD546 - WD552 1

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

November 20, 2008

777-78A0070

9 of 22
Variable Number Group

WD561 - WD571 1

WD581 - WD594 1

WD606 - WD609 1

WD621 - WD632 1

WD651 - WD657 1

WD671 - WD675 1

WD691 - WD701 1

WD741 - WD745 1

WD761 - WD768 1

WD786 - WD787 1

WD796 - WD799 1

WD826 - WD828 1

WD846 1

WD871 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

General Electric 79-0017 Inspection of GE Engine Oil Scavenge Tube

(GE)

C. Reason

Accomplishment of this service bulletin will prevent interference between an oil scavenge tube on the

Turbine Rear Frame (TRF) of the General Electric (GE) engine and an aft cowl insulation blanket bolt.

This interference can cause damage to the oil scavenge tube. This damage could result in a puncture

in the oil scavenge tube. A punctured oil scavenge tube would cause oil loss and could cause an in-flight

shutdown of the engine.

Boeing determined that there was insufficient clearance between an oil scavenge tube on the GE

engine and an aft cowl insulation blanket bolt. This location could experience interference under flight

loads. Damage to the oil scavenge tube was confirmed at Boeing on non-delivered airplanes after

flight. Several in-service airplanes were also inspected. Many of the airplanes showed damage because

of the interference condition. The damage was limited to dents, gouges, or chafing. However, some of

the damage that was found was outside of serviceable limits. No oil tube punctures were found or

reported.

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

November 20, 2008

777-78A0070

10 of 22

BOEING SERVICE BULLETIN 777-78A0070

ALERT ALERT
This service bulletin provides instructions to replace the aft cowl insulation blanket fasteners at one

location to gain additional clearance from the oil scavenge tube and remove the possible interference

condition.

There are two related vendor service bulletins. GE Service Bulletin 79-0017 provides instructions to

inspect the oil scavenge tube for damage and should be done concurrently with this service bulletin.

GE Service Bulletin 79-0019 provides instructions to replace the oil scavenge tube with a new tube

that will increase clearance with the insulation blanket bolt.

Boeing Service Related Problem (SRP) 777-SRP-72-0032 is related to this service bulletin.

D. Description

Open the left thrust reverser. Remove the lower aft cowl insulation blanket. Change the fasteners at

one location. Install the removed insulation blanket. Close the thrust reverser.

The work in this service bulletin is done in the maintenance zone(s) given below.

Affected Maintenance Zones

Model Zone

777-200LR, 777-300ER 417

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.

Boeing recommends that the change given in this service bulletin be done within 180 days or 300 flight

cycles after the date on this service bulletin, whichever occurs later.

F. Approval

This service bulletin was examined by the Federal Aviation Administration (FAA).The changes specified

in this service bulletin comply with the applicable regulations and are FAA approved, as well as European

Aviation Safety Agency (EASA)/Joint Aviation Authorities (JAA) approved for all EASA/JAA approved

airplanes listed in the service bulletin effectivity. This service bulletin and its approval were based on

the airplane in its original Boeing delivery configuration or as modified by other approved Boeing

changes.

If an airplane has a non-Boeing modification or repair that affects a component or system also affected

by this service bulletin, the operator is responsible for obtaining appropriate regulatory agency approval

before incorporating this service bulletin.

G. Manpower

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

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:

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

November 20, 2008

777-78A0070

11 of 22

BOEING SERVICE BULLETIN 777-78A0070

ALERT ALERT
• Time to adjust to the workplace

• Time to schedule the work

• Time to inspect the work

• Time to cure the materials

• Time to make the parts

• Time to find the tools.

Number of Task Hours Elapsed Hours

Persons

Task

Open Access 1 0.50 0.50

Figure 1 1 1.50 1.50

Close Access 1 0.50 0.50

TOTAL FOR EACH ENGINE 2.50 2.50

H. Weight and Balance Changes

None.

I. Electrical Load Data

Not changed.

J. References

1. Existing Data

a. Service Related Problem (SRP) 777-SRP-72-0032

b. Boeing Service Letter (SL) 777-SL-78-021

c. Boeing Fleet Team Digest (FTD) Article 777-FTD-79-08001

d. 777 Aircraft Maintenance Manual (AMM) 78-31-00, 78-31-06

e. General Electric (GE) Service Bulletin 79-0017, 79-0019

NOTE: The supplier was told to send copies of the service bulletin to each operator.

2. Data supplied with this Service Bulletin

None.

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

Drawing Number Title

315W1810 Insulation Blanket Instl. - T/R Fan Duct Inner Wall

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

November 20, 2008

777-78A0070

12 of 22

BOEING SERVICE BULLETIN 777-78A0070

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

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

not be applicable to all airplane configurations or operators.

K. Publications Affected

Publication Chapter-Section

777 Illustrated Parts Catalog 78-31

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.

November 20, 2008

777-78A0070

13 of 22

BOEING SERVICE BULLETIN 777-78A0070

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

November 20, 2008

777-78A0070

14 of 22

BOEING SERVICE BULLETIN 777-78A0070

ALERT ALERT

BLANK PAGE
2. MATERIAL INFORMATION

A. Material - Price and Availability

Boeing can supply the kits shown in Paragraph 2.C., Parts Necessary for Each Airplane , and Paragraph

2.D., Parts Necessary to Change Spares, as shown below. 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.

Unit Price thru

December 31,

2008

ROLT

(Weeks)

Kit Number Name Date QTY

Jul. 14, 20 35 $46.60

2008

Top Kit - GE Thrust

Reverser Blanket Bolt

Replacement

005W3383-1

Jul. 28, 20

2008

Aug. 11, 24

2008

Sep. 11, 20

2008

Oct. 9, 20

2008

Nov. 6, 20

2008

Dec. 8, 20

2008

Jan. 14, 20

2009

Feb. 11, 20

2009

Mar. 11, 20

2009

Apr. 8, 20

2009

May 6, 20

2009

Jun. 4, 18

2009

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.

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

November 20, 2008

777-78A0070

15 of 22

BOEING SERVICE BULLETIN 777-78A0070

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

follow:

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

2. Fax to (206) 662-7145

3. Spares Customer Support - MC 36-65

Boeing Spares Department

P.O. Box 3707

Seattle, Washington 98124-2207 USA

B. Industry Support Information

Boeing warranty remedies are not available for the configuration changes given in this service bulletin.

C. Parts Necessary For Each Airplane

1. Kits/Parts

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

NOTE: One top kit and the items shown in Paragraph 2.C.2., Parts and Materials Supplied by

the Operator, are necessary for each engine.

Kit 005W3383

Existing Part Notes

Number

New Part Number QTY Name

-1

Top Kit - GE Thrust

Reverser Blanket

Bolt Replacement

005W3383-1 -

315W1819-2 or

315W1819-6

315W1819-7 1 BOLT

BACN10YR3C 1 NUT

BACW10P392CC 1 WASHER, PLAIN

(BACW10P458CD

optional)

MS15795-857 1 WASHER

RH30C3NL 1 NUT

2. Parts and Materials Supplied by the Operator

None.

3. Parts Modified and Reidentified

None.

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

November 20, 2008

777-78A0070

16 of 22

BOEING SERVICE BULLETIN 777-78A0070

ALERT ALERT
4. Parts Removed and Not Replaced

None.

D. Parts Necessary to Change Spares

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

Kit Number Name QTY

Top Kit - GE Thrust 1

Reverser Blanket Bolt

Replacement

005W3383-1

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.

November 20, 2008

777-78A0070

17 of 22

BOEING SERVICE BULLETIN 777-78A0070

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

November 20, 2008

777-78A0070

18 of 22

BOEING SERVICE BULLETIN 777-78A0070

ALERT ALERT

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. These work instructions refer to procedures included in other Boeing documents.

When the words "refer to" are used and the operator has an accepted alternative

procedure, the accepted alternative procedure can be used. When the words "as

given in" are included in the instruction, the procedure in the Boeing document must

be used.

B. WORK INSTRUCTIONS

1. Open the left Thrust Reverser. Refer to 777 AMM 78-31-00 as an accepted procedure.

2. Replace the insulation blanket fasteners on the aft cowl as given in Figure 1.

3. Close the left Thrust Reverser. Refer to 777 AMM 78-31-00 as an accepted procedure.

4. Put the airplane back to a serviceable condition.

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

November 20, 2008

777-78A0070

19 of 22

BOEING SERVICE BULLETIN 777-78A0070

ALERT ALERT
FIGURE 1: THRUST REVERSER - AFT COWL INSULATION BLANKET - FASTENER CHANGE

(SHEET 1 OF 3)

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

November 20, 2008

777-78A0070

20 of 22

BOEING SERVICE BULLETIN 777-78A0070

ALERT ALERT
FIGURE 1: THRUST REVERSER - AFT COWL INSULATION BLANKET - FASTENER CHANGE

(SHEET 2 OF 3)

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

November 20, 2008

777-78A0070

21 of 22

BOEING SERVICE BULLETIN 777-78A0070

ALERT ALERT
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 engine.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

Refer to 777 AMM

78-31-06 as an

accepted procedure.

Blanket Assembly - Aft 315W1768-1 1

Cowl

1 Remove / Keep

315W1819-2 0R 1

315W1819-6

2 Remove Bolt

Remove Washer - -

Remove Nut - -

3 Install (New) Bolt 315W1819-7 1

Install (New) Washer MS15795-857 1

Torque to 25-35

inch-pounds.

Install (New) Nut RH30C3NL 1

Refer to 777 AMM

78-31-06 as an

accepted procedure.

Blanket Assembly - Aft 315W1768-1 1

Cowl

4 Install (Kept)

BACW10P458CD

washer is optional to

the

BACW10P392CC

washer.

5 Install (New) Washer BACW10P392CC 1

Torque to 20-25

inch-pounds.

Install (New) NUT BACN10YR3C 1

6 Grind Bolt 315W1819-7 1 (OPTIONAL) (a)

(a) This step is optional. If damage to the GE oil scavenge tube is found during inspection as given in GE

service bulletin 79-0017, operators can grind the 315W1819-7 bolt to provide additional clearance. Grind

the bolt until there is a minimum 1.5 threads protruding.

FIGURE 1: THRUST REVERSER - AFT COWL INSULATION BLANKET - FASTENER CHANGE

(SHEET 3 OF 3)

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

November 20, 2008

777-78A0070

22 of 22

BOEING SERVICE BULLETIN 777-78A0070

ALERT ALERT