### 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. 9E991 ECCN: 

## BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET Copyright © 2008 The Boeing Company Unpublished Work - All Rights Reserved Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable subject matter.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BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. November 20, 2008 777-78A0070 1 of 22 2.0BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details.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**

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### 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 Elapsed Hours**  **Total Task Hours Engines**  2.50 2.50 Each Engine
**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**

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### 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.
**DESCRIPTION CONFIGURATION**  **GROUP** 777-200LR and -300ER Airplanes with GE90-100 Engines

- 1

Airplane Models: 777-200LR, 777-300ER **Group Variable Number**  1 WD001 - WD002 1 WD011 - WD014 1 WD031 - WD033 1 WD046 - WD048 1 WD501 - WD507 1 WD521 - WD537 1 WD546 - WD552

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. November 20, 2008 777-78A0070 9 of 22**Group Variable Number**  1 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 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: **Description Service Bulletin**  **Company** Inspection of GE Engine Oil Scavenge Tube 79-0017 General Electric (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 Zone**  **Model** 417 777-200LR, 777-300ER **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. **Elapsed Hours Task Hours**  **Number of Persons**  **Task**
0.50 0.50 1 Open Access 1.50 1.50 1 Figure 1 0.50 0.50 1 Close Access 2.50 2.50 TOTAL FOR EACH ENGINE **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 **NO TE:**  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
**Title Drawing Number**  Insulation Blanket Instl. - T/R Fan Duct Inner Wall 315W1810

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 Chapter-Section** 

**Publication** 78-31 777 Illustrated Parts Catalog **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) QTY**  **Date Name**  **Kit Number**

$46.60 35 20 Jul. 14, 2008 Top Kit - GE Thrust Reverser Blanket Bolt Replacement 005W3383-1
20 Jul. 28, 2008 24 Aug. 11, 2008 20 Sep. 11, 2008 20 Oct. 9, 2008 20 Nov. 6, 2008 20 Dec. 8, 2008 20 Jan. 14, 2009 20 Feb. 11, 2009 20 Mar. 11, 2009 20 Apr. 8, 2009 20 May 6, 2009 18 Jun. 4, 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 Ref** **erence this ser vice b** **ulletin and submit y our pur** **c hase or** **der b y one of the methods that**  **f ollo** **w:** 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. **NO TE:**  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 Notes**  **Existing Part Number**  **Name QTY**  **New Part Number -1**  Top Kit - GE Thrust Reverser Blanket Bolt Replacement - 005W3383-1

315W1819-2 or 315W1819-6 BOLT 1 315W1819-7
NUT 1 BACN10YR3C WASHER, PLAIN 1 BACW10P392CC (BACW10P458CD optional) WASHER 1 MS15795-857 NUT 1 RH30C3NL 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.
**QTY Name**  **Kit Number** 1 Top Kit - GE Thrust 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**  **CA UTION:**  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. **NO TE:**  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.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP**  Refer to 777 AMM 78-31-06 as an accepted procedure. 1 315W1768-1 Blanket Assembly - Aft Cowl Remove / Keep 1

1 315W1819-2 0R 315W1819-6 Bolt Remove 2

- - Washer Remove

- - Nut Remove 1 315W1819-7 Bolt Install (New) 3 1 MS15795-857 Washer Install (New) Torque to 25-35 inch-pounds. 1 RH30C3NL Nut Install (New)
Refer to 777 AMM 78-31-06 as an accepted procedure. 1 315W1768-1 Blanket Assembly - Aft Cowl Install (Kept) 4

BACW10P458CD washer is optional to the BACW10P392CC washer. 1 BACW10P392CC Washer Install (New) 5

Torque to 20-25 inch-pounds. 1 BACN10YR3C NUT Install (New) (OPTIONAL) (a) 1 315W1819-7 Bolt Grind 6 (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**