Commercial 

Airplanes 777

Service Bulletin

SPECIAL ATTENTION

Number: 777-54-0028

Original Issue: May 25, 2012

Revision 1: December 10, 2013

ATA System: 5451

SUBJECT: NACELLES / PYLONS - Nacelle Strut - PW4000 Forward Dry Bay and Forward Engine

Mount Bulkhead - Inspection

Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15

CFR 300-774). An export license may be required before it is used for development, production or use by foreign

persons from specific countries. The controller of this data has the individual responsibility to abide by all export

laws.

ECCN: 9E991

BOEING PROPRIETARY, CONFIDENTIAL AND/OR TRADE SECRET

Copyright © 2012 Boeing.

Unpublished Work. All Rights Reserved.

Treatment of this document and its content is governed by contract with Boeing. Rights to use this document

are licensed on a per aircraft basis and such rights may not be transferable. For more information, contact The

Boeing Company.

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connection with this document unless provided in writing by Boeing.

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Revision 1: December 10, 2013 777-54-0028

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3.0
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BOEING SERVICE BULLETIN 777-54-0028

BLANK PAGE
Table of Contents

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

Summary ...................................................... 9

1. PLANNING INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

A. Effectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

1. Airplanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

B. Concurrent Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

C. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

E. Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

H. Weight and Balance Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

1. Existing Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

2. Data Supplied with this Service Bulletin: . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

3. Installation Drawings Used in the Preparation of this Service Bulletin: . . . . . . . . . . . 21

K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

M. Software Accomplishment Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

2. MATERIAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

A. Material - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

C. Parts Necessary for Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

1. Kits/Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

2. Parts and Materials Supplied by the Operator . . . . . . . . . . . . . . . . . . . . . . . . 23

3. Parts Modified and Reidentified . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

4. Parts Removed and Not Replaced . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

D. Parts Necessary to Change Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

E. Special Tooling - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

F. Special Tooling Necessary to do this Service Bulletin . . . . . . . . . . . . . . . . . . . . . . . 24

3. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

B. WORK INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

FIGURE 1: STRUT NO. 1 - FORWARD DRY BAY INTERIOR - GVI INSPECTION . . . . . . . . . . . 30

FIGURE 2: STRUT NO. 1 - FORWARD DRY BAY INTERIOR - DET INSPECTION . . . . . . . . . . 32

FIGURE 3: STRUT NO. 1 - FORWARD ENGINE MOUNT BULKHEAD FITTING - DET AND HFEC

INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

FIGURE 4: STRUT NO. 2 - FORWARD DRY BAY INTERIOR - GVI INSPECTION . . . . . . . . . . . 38

FIGURE 5: STRUT NO. 2 - FORWARD DRY BAY INTERIOR - DET INSPECTION . . . . . . . . . . 40

FIGURE 6: STRUT NO. 2 - FORWARD ENGINE MOUNT BULKHEAD FITTING - DET AND HFEC

INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

APPENDIX A: CLEANING AND REFINISHING OF STRUT FWD DRY BAY DETAILS . . . . . . . . . . 46

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BOEING SERVICE BULLETIN 777-54-0028

BLANK PAGE
Commercial 

Airplanes 777

Service Bulletin

SPECIAL ATTENTION

Revision Transmittal Sheet Number: 777-54-0028

Original Issue: May 25, 2012

Revision 1: December 10, 2013

ATA System: 5451

SUBJECT: NACELLES / PYLONS - Nacelle Strut - PW4000 Forward Dry Bay and Forward Engine

Mount Bulkhead - Inspection

This revision includes all pages of the service bulletin.

COMPLIANCE INFORMATION RELATED TO THIS REVISION

Federal Aviation Administration (FAA) Airworthiness Directive AD 2013-11-14 is related to this service bulletin.

Airplanes WC587, WC593, WC594, and WC595 were added to the service bulletin effectivity as Group 2

Airplanes. These airplanes should accomplish the initial inspection at the compliance time in accordance with

Paragraph 1.E., Compliance.

No more work is necessary on the airplanes inspected in accordance with the original issue of this service

bulletin. These airplanes should repeat the inspection at the repeat interval in accordance with Paragraph 1.E.,

Compliance.

REASON FOR REVISION

This revision is sent to:

1. Add airplanes WC587, WC593, WC594, and WC595 to the effectivity of this service bulletin as Group

2 Airplanes. Subsequent to the release of this service bulletin it was determined that a production

change that was to be installed on these airplanes that would have terminated the inspections in this

service bulletin could not be installed. Therefore the inspection of these airplanes in accordance with

this service bulletin is required. Group 2 Airplanes are the same as Group 1 Airplanes, except for the

compliance time for the initial inspection.

2. Revise compliance table and work instructions to show that finish restoration is not required until the

repairs are required.

3. Clarify that hydraulic fluid contamination includes hydraulic fluid contamination in its liquid (fluid), vapor,

and/or solid (coked) form.

4. Add optional leveling compound.

5. Add an alternate method of leveling compound repair for small areas that uses sealant and does not

require airplane leveling.

These sections were changed:

Export Controlled ECCN: 9E991 - BOEING

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5 of 49
1. Summary:

a. Background - Revise to show hydraulic fluid contamination can be in the form of a liquid (fluid),

vapor, or solid (coke). Revise hydraulic fluid to hydraulic fluid contamination at 4 locations.

b. Action - Revise Part 1 to show hydraulic fluid contamination can be in the form of a liquid (fluid),

vapor, or solid (coke) and blistered and/or peeling primer is a sign of hydraulic fluid contamination.

c. Compliance - Add FAA AD.

2. Planning Information:

a. Paragraph 1.C., Reason:

(1) Revise to show hydraulic fluid contamination can be in the form of a liquid (fluid), vapor, or

solid (coke). Revise hydraulic fluid to hydraulic fluid contamination at 4 locations.

(2) Add Reason for this revision information.

b. Paragraph 1.D., Description:

(1) Revise Part 1 to show hydraulic fluid contamination can be in the form of a liquid (fluid), vapor,

or solid (coke) and blistered and/or peeling primer is a sign of hydraulic fluid contamination.

(2) Add "Compliance Information Related to This Revision".

(3) add Affected Maintenance Zone Table for Group 2 Airplanes.

c. Paragraph 1.E., Compliance:

(1) Add FAA AD.

(2) Revise Table 1, row 1 to limit condition to Group 1 Airplanes.

(3) Add Table 1, row 2 for Group 2 Airplanes. Group 2 Airplanes have initial compliance from

revision 1 date, instead of from the effective date of the AD.

(4) Revise to show hydraulic fluid contamination can be in the form of a liquid (fluid), vapor, or

solid (coke) in multiple locations in Table 1.

(5) Clarify that the compliance time in Table 1, second action for condition 2B is from the time

Condition 2B is found.

(6) Clarify that restore sealant, primer and leveling compound can be accomplished at the same

compliance time as the repair in Table 1, second action for condition 2B.

(7) Clarify that restoration of sealant, primer, and leveling compound can be accomplished at the

same compliance time as the repair in Table 1, first action for condition 2C.

d. Paragraph 1.F., Approval:

(1) Add statement approving this service bulletin as an alternate method of compliance (AMOC)

to FAA AD.

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BOEING SERVICE BULLETIN 777-54-0028
e. Paragraph 1.J.1., Existing Data:

(1) Add FAA AD.

3. Material Information:

a. Paragraph 2.C.2., Parts and Materials Supplied by the Operator:

(1) Add optional leveling compound. Change finishes to sealant, primer, and leveling compound.

4. Accomplishment Instructions:

a. Paragraph 3.A., General Information - No Changes

b. Paragraph 3.B., Work Instructions:

(1) General Work Instructions:

(a) Revise to show hydraulic fluid contamination can be in the form of a liquid (fluid), vapor,

or solid (coke) in 6 locations.

(b) Move restoration of sealant, primer, and leveling compound from Part 2, Step 4 to the

second action for condition 2B. Move restoration of sealant, primer, and leveling compound

from Part 3, Step 4 to the first action for condition 2C.

(2) Part 1:

(a) Step 3 - Revise to show hydraulic fluid contamination can be in the form of a liquid (fluid),

vapor, or solid (coke).

(3) Part 2:

(a) Delete Step 4 and move restoration of sealant, primer, and leveling compound to the

second action for condition 2B.

(4) Part 3:

(a) Delete Step 4 and move restoration of sealant, primer, and leveling compound to the first

action for condition 2C.

(5) FIGURE 1:

(a) Illustration: No changes.

(b) Step Table:

1) Step 1 - Revise to show hydraulic fluid can be in the form of a liquid (fluid), vapor,

or solid (coke). Revise to show that blistered and/or peeling primer is a sign of

hydraulic fluid contamination.

(6) FIGURE 4:

(a) Illustration: No changes.

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BOEING SERVICE BULLETIN 777-54-0028
(b) Step Table:

1) Step 1 - Revise to show hydraulic fluid can be in the form of a liquid (fluid), vapor,

or solid (coke). Revise to show that blistered and/or peeling primer is a sign of

hydraulic fluid contamination.

(7) APPENDIX A:

(a) Illustrations: No changes.

(b) Step Table:

1) Note - Add optional sealant repair.

2) Step 7 - Add optional leveling compound. Refer to optional sealant repair.

3) Step 8 - Add optional leveling compound. Refer to optional sealant repair.

4) Step 9 - Add option to use sealant to repair small areas of leveling compound. The

option does not require the airplane to be leveled.

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

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BOEING SERVICE BULLETIN 777-54-0028
Commercial 

Airplanes 777

Service Bulletin

SPECIAL ATTENTION

Summary Number: 777-54-0028

Original Issue: May 25, 2012

Revision 1: December 10, 2013

ATA System: 5451

SUBJECT: NACELLES / PYLONS - Nacelle Strut - PW4000 Forward Dry Bay and Forward Engine

Mount Bulkhead - Inspection

BOEING RECOMMENDS THAT EACH OPERATOR EXAMINE THIS SERVICE BULLETIN IMMEDIATELY.

CONCURRENT REQUIREMENTS

None.

BACKGROUND

Accomplishment of the inspections in this service bulletin will find hydraulic fluid contamination in its liquid (fluid),

vapor, and/or solid (coked) form in the strut forward dry bay, before the forward engine mount bulkhead fittings

become sufficiently hydrogen embrittled that they can not carry design loads. If hydraulic fluid contamination is

on the titanium forward engine mount bulkhead fittings, hydrogen embrittlement of the fittings can occur. When

the forward engine mount bulkhead fitting becomes sufficiently hydrogen embrittled it cannot carry design load

and loses limit load capability that can lead to the loss or departure of an engine. Similarly, hydrogen embrittlement

of the fittings can cause through crack formation across the fitting. Such through cracks might not contain an

engine fire and allow the fire to breach into the strut. The forward engine mount bulkhead fitting does not have

fire detection or fire suppression capability. Thus, a fire breaching the forward engine mount bulkhead fitting

can lead to an uncontained fire in the strut.

One operator has reported 5 airplanes with hydraulic fluid residue in the strut forward dry bay. The airplanes

had approximately 9,900 to 29,000 flight-cycles and 13,000 to 33,300 flight-hours. The forward engine mount

bulkhead fittings are made from titanium and are located near the hot engine core of the engine where

temperatures can exceed 270 degrees Fahrenheit. The presence of hydraulic fluid contamination and temperature

above 270 degrees Fahrenheit can result in hydrogen embrittlement of the titanium forward engine mount

bulkhead fittings. If the forward engine mount bulkhead fittings become sufficiently hydrogen embrittled, they

may not be able to carry design loads. It is believed that hydraulic fluid contamination is entering the dry bay

through the condensate drain line. The condensate drain connects to the system disconnect box drain lines,

which drains hydraulic fluid and fuel from the system disconnect box. The system disconnect box drain hose

can clog due to hydraulic fluid coking in the drain lines. This allows hydraulic fluid to back up into strut forward

dry bay through the condensate drain line. Boeing Service Bulletin 777-54-0027 addresses blockage of the strut

forward drain lines. If a fitting becomes embrittled, fitting and/or strut replacement may be required. If the fitting

becomes sufficiently brittle, it may not be able to carry design loads.

Inspection of the strut forward dry bay for the presence of hydraulic fluid contamination will help prevent hydrogen

embrittlement of the titanium forward engine mount bulkhead fittings.

Boeing Fleet Team Digest (FTD) 777 FTD 54-11001 is related to this service bulletin.

Export Controlled ECCN: 9E991 - BOEING

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Boeing Service Related Problem (SRP) 777-SRP-54-0138 is related to this service bulletin.

This table is provided to operators for planning purposes only. Refer to the applicable sections for more

information.

Planning Data Affected Reference

Spares Affected No Paragraph 1.A.2., Spares Affected

AD Related Yes Paragraph 1.E., Compliance

Weight and Balance Change No Paragraph 1.H., Weight and Balance Changes

Electrical Load Changed No Paragraph 1.I., Electrical Load Data

Publications Affected No Paragraph 1.K., Publications Affected

Airplane Flight Operations Affected (Flight Crew No Paragraph 1.K., Publications Affected

Operations Manual and/or FAA Approved Airplane Flight Manual)

Kits/Parts Required No Paragraph 2.C.1., Kits/Parts

Paragraph 2.C.2., Parts and Materials Supplied

by the Operator

Operator Supplied Material No

Paragraph 2.F., Special Tooling Necessary to

do this Service Bulletin

Special Tooling Required No

ACTION

Part 1 - Strut Forward Dry Bay Hydraulic Fluid Contamination GVI Inspection

Open the thrust reverser. Remove the strut forward dry bay access door. Do a General Visual Inspection (GVI)

for hydraulic fluid contamination in its liquid (fluid), vapor, and/or solid (coked) form. Blistered and/or peeling

primer is a sign of hydraulic fluid contamination and the strut forward dry bay is contaminated. Install the strut

forward dry bay access door. Close the thrust reverser.

Part 2 - Strut Forward Dry Bay Interior DET Inspection

Open the thrust reverser. Remove the strut forward dry bay access door. Do a Detailed Inspection (DET) of the

interior of the strut forward dry bay for hydraulic fluid coking, heat discoloration, damage to sealant and primer,

damage to leveling compound, cracks; and etching or pitting. Clean and restore sealant, primer, and leveling

compound of the detail parts in the strut forward dry bay if missing, blistered, peeling, or damaged. Check drain

lines and clean or replace drain lines as required. Install the strut forward dry bay access door. Close the thrust

reverser.

Part 3 - Strut Forward Engine Mount Bulkhead Fitting DET and HFEC Inspection

Open the thrust reverser. Remove the strut forward dry bay access door. Do a DET and High Frequency Eddy

Current (HFEC) inspection of the strut forward engine mount bulkhead upper and lower fittings for cracks, and

etching or pitting. Clean and restore sealant, primer, and leveling compound of the detail parts in the strut forward

dry bay if missing, blistered, peeling, or damaged. Check drain lines and clean or replace drain lines as required.

Install the strut forward dry bay access door. Close the thrust reverser.

Export Controlled ECCN: 9E991 - BOEING

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BOEING SERVICE BULLETIN 777-54-0028
EFFECTIVITY

777-200 and -300 Airplanes powered by PW4000 Engines. Refer to Paragraph 1.A.1., Airplanes, for the list of

affected airplanes.

COMPLIANCE

Federal Aviation Administration (FAA) Airworthiness Directive AD 2013-11-14 is related to this service bulletin.

Refer to Paragraph 1.E., Compliance.

INDUSTRY SUPPORT INFORMATION

Boeing warranty remedies are available for airplanes in warranty as of June 15, 2011. Please refer to Paragraph

2.B., Industry Support Information.

MANPOWER

Total Task Hours Elapsed Hours

Part 1 - Strut Forward Dry Bay Hydraulic 5.00 3.00

Fluid Contamination GVI Inspection

Part 2 - Strut Forward Dry Bay Interior 17.00 12.50

DET Inspection

Part 3 - Strut Forward Engine Mount 17.00 12.50

Bulkhead Fitting DET and HFEC Inspection

MATERIAL INFORMATION

Operator Supplied Parts/Materials.

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

Export Controlled ECCN: 9E991 - BOEING

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Export Controlled ECCN: 9E991 - BOEING

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BOEING SERVICE BULLETIN 777-54-0028
Commercial 

Airplanes 777

Service Bulletin

SPECIAL ATTENTION

Number: 777-54-0028

Original Issue: May 25, 2012

Revision 1: December 10, 2013

ATA System: 5451

SUBJECT: NACELLES / PYLONS - Nacelle Strut - PW4000 Forward Dry Bay and Forward Engine

Mount Bulkhead - Inspection

BOEING RECOMMENDS THAT EACH OPERATOR EXAMINE THIS SERVICE BULLETIN IMMEDIATELY.

1. PLANNING INFORMATION

A. Effectivity

1. Airplanes

This service bulletin is for the airplane(s) shown below.

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

Serial Number data.

GROUP CONFIGURATION DESCRIPTION

777-200 and -300 Airplanes line numbers 2 through 1027 powered

by Pratt and Whitney (PW) 4000 Engines.

1 -

777-200 and -300 Airplanes line numbers 1090 through 1117 powered

by Pratt and Whitney (PW) 4000 Engines.

2 -

Airplane Models:

777-200, 777-300

Variable Number Group

WA002 - WA017 1

WA131 - WA137 1

WA171 - WA175 1

WA206 - WA212 1

WA221 - WA223 1

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Variable Number Group

WA231 - WA232 1

WA241 - WA250 1

WA261 - WA266 1

WA281 - WA283 1

WA301 - WA304 1

WB051 - WB088 1

WB131 - WB148 1

WB151 - WB155 1

WB366 - WB368 1

WB481 - WB484 1

WB531 - WB537 1

WB551 - WB554 1

WB591 - WB597 1

WC111 - WC120 1

WC371 - WC374 1

WC506 - WC508 1

WC581 1

WC586 1

WC587 2

WC591 - WC592 1

WC593 - WC595 2

2. Spares Affected

None.

B. Concurrent Requirements

None.

C. Reason

Accomplishment of the inspections in this service bulletin will find hydraulic fluid contamination in its

liquid (fluid), vapor, or solid (coked) form in the strut forward dry bay, before the forward engine mount

bulkhead fittings become sufficiently hydrogen embrittled that they can not carry design loads. If hydraulic

fluid contamination is on the titanium forward engine mount bulkhead fittings, hydrogen embrittlement

of the fittings can occur. When the forward engine mount bulkhead fitting becomes sufficiently hydrogen

embrittled it cannot carry design load and loses limit load capability that can lead to the loss or departure

Export Controlled ECCN: 9E991 - BOEING

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BOEING SERVICE BULLETIN 777-54-0028
of an engine. Similarly, hydrogen embrittlement of the fittings can cause through crack formation across

the fitting. Such through cracks might not contain an engine fire and allow the fire to breach into the

strut. The forward engine mount bulkhead fitting does not have fire detection or fire suppression

capability. Thus, a fire breaching the forward engine mount bulkhead fitting can lead to an uncontained

fire in the strut.

One operator has reported 5 airplanes with hydraulic fluid residue in the strut forward dry bay. The

airplanes had approximately 9,900 to 29,000 flight-cycles and 13,000 to 33,300 flight-hours. The forward

engine mount bulkhead fittings are made from titanium and are located near the hot engine core of the

engine where temperatures can exceed 270 degrees Fahrenheit. The presence of hydraulic fluid

contamination and temperature above 270 degrees Fahrenheit can result in hydrogen embrittlement

of the titanium forward engine mount bulkhead fittings. If the forward engine mount bulkhead fittings

become sufficiently hydrogen embrittled, they may not be able to carry design loads. It is believed that

hydraulic fluid contamination is entering the dry bay through the condensate drain line. The condensate

drain connects to the system disconnect box drain lines, which drains hydraulic fluid and fuel from the

system disconnect box. The system disconnect box drain hose can clog due to hydraulic fluid coking

in the drain lines. This allows hydraulic fluid to back up into strut forward dry bay through the condensate

drain line. Boeing Service Bulletin 777-54-0027 addresses blockage of the strut forward drain lines. If

a fitting becomes embrittled, fitting and/or strut replacement may be required. If the fitting becomes

sufficiently brittle, it may not be able to carry design loads.

Inspection of the strut forward dry bay for the presence of hydraulic fluid contamination will help prevent

hydrogen embrittlement of the titanium forward engine mount bulkhead fittings.

Boeing Fleet Team Digest (FTD) 777 FTD 54-11001 is related to this service bulletin.

Boeing Service Related Problem (SRP) 777-SRP-54-0138 is related to this service bulletin.

Revision 1 is sent to:

1. Add airplanes WC587, WC593, WC594, and WC595 to the effectivity of this service bulletin as

Group 2 Airplanes. Subsequent to the release of this service bulletin it was determined that a

production change that was to be installed on these airplanes that would have terminated the

inspections in this service bulletin could not be installed. Therefore the inspection of these airplanes

in accordance with this service bulletin is required. Group 2 Airplanes are the same as Group 1

Airplanes, except for the compliance time for the initial inspection.

2. Revise compliance table and work instructions to show that finish restoration is not required until

the repairs are required.

3. Clarify that hydraulic fluid contamination includes hydraulic fluid contamination in its liquid (fluid),

vapor, and/or solid (coked) form.

4. Add optional leveling compound.

5. Add an alternate method of leveling compound repair for small areas that uses sealant and does

not require airplane leveling.

D. Description

Part 1 - Strut Forward Dry Bay Hydraulic Fluid Contamination GVI Inspection

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Open the thrust reverser. Remove the strut forward dry bay access door. Do a General Visual Inspection

(GVI) for hydraulic fluid contamination in its liquid (fluid), vapor, and/or solid (coked) form. Blistered

and/or peeling primer is a sign of hydraulic fluid contamination and the strut forward dry bay is

contaminated. Install the strut forward dry bay access door. Close the thrust reverser.

Part 2 - Strut Forward Dry Bay Interior DET Inspection

Open the thrust reverser. Remove the strut forward dry bay access door. Do a Detailed Inspection

(DET) of the interior of the strut forward dry bay for hydraulic fluid coking, heat discoloration, damage

to sealant and primer, damage to leveling compound, cracks; and etching or pitting. Clean and restore

sealant, primer, and leveling compound of the detail parts in the strut forward dry bay if missing, blistered,

peeling, or damaged. Check drain lines and clean or replace drain lines as required. Install the strut

forward dry bay access door. Close the thrust reverser.

Part 3 - Strut Forward Engine Mount Bulkhead Fitting DET and HFEC Inspection

Open the thrust reverser. Remove the strut forward dry bay access door. Do a DET and High Frequency

Eddy Current (HFEC) inspection of the strut forward engine mount bulkhead upper and lower fittings

for cracks, and etching or pitting. Clean and restore sealant, primer, and leveling compound of the

detail parts in the strut forward dry bay if missing, blistered, peeling, or damaged. Check drain lines

and clean or replace drain lines as required. Install the strut forward dry bay access door. Close the

thrust reverser.

Revision 1 - Airplanes WC587, WC593, WC594, and WC595 were added to the service bulletin effectivity

as Group 2 Airplanes. These airplanes should accomplish the initial inspection at the compliance time

in accordance with Paragraph 1.E., Compliance. No more work is necessary on the airplanes inspected

in accordance with the original issue of this service bulletin. These airplanes should repeat the inspection

at the repeat interval in accordance with Paragraph 1.E., Compliance.

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

Group 1:

Affected Maintenance Zones

Model Zone

777-200, 777-300 432, 442

Group 2:

Affected Maintenance Zones

Model Zone

777-200 432, 442

E. Compliance

Federal Aviation Administration (FAA) Airworthiness Directive AD 2013-11-14 is related to this service

bulletin. The effective date of AD 2013-11-14 is July 19, 2013.

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BOEING SERVICE BULLETIN 777-54-0028
Accomplish the required actions, based on the applicable conditions, in Table 1, in accordance with

Paragraph 3. Accomplishment Instructions.

Accomplish the actions and evaluate the conditions in Table 1 separately for each strut forward dry

bay and each forward engine mount bulkhead.

The following acronyms are used in Table 1:

– GVI for General Visual Inspection.

– DET for Detailed Inspection.

– HFEC for High Frequency Eddy Current Inspection.

– Part 1 for Part 1 - Strut Forward Dry Bay Hydraulic Fluid Contamination GVI Inspection.

– Part 2 for Part 2 - Strut Forward Dry Bay Interior DET Inspection.

– Part 3 for Part 3 - Strut Forward Engine Mount Bulkhead Fitting DET and HFEC Inspection

Table 1: GVI, DET, and HFEC Inspection of Strut Forward Dry Bay for Hydraulic Fluid Contamination

and Forward Engine Mount Bulkhead for Hydrogen Embrittlement.

Repeat Interval

(Not to Exceed)

Condition Action Compliance Time

Within 600 flight-cy- -

cles or 12 Months after the effective date

of AD 2013-11-14,

whichever occurs

first.

Do a GVI of the interior of the

strut forward dry bay for hydraulic fluid contamination in its

liquid (fluid), vapor, and/or solid

(coked) form in accordance with

Part 1.

Group 1 Airplanes

Within 600 flight-cy- -

cles or 12 Months after the Revision 1

date of this service

bulletin, whichever

occurs first.

Do a GVI of the interior of the

strut forward dry bay for hydraulic fluid contamination in its

liquid (fluid), vapor, and/or solid

(coked) form in accordance with

Part 1.

Group 2 Airplanes

1,200 Flight-cycles.Repeat GVI of the interior of the -

strut forward dry bay for hydraulic fluid contamination in its

liquid (fluid), vapor, and/or solid

(coked) form in accordance with

Part 1.

Condition 1 -

No hydraulic fluid contamination in

its liquid (fluid), vapor, and/or solid

(coked) form is found.

Do a DET of the interior of the Before further flight. -

strut forward dry bay in accordance with Part 2 for: 1) Hydraulic fluid coking; and 2) Heat

discoloration; and 3) Damage to

sealant and primer; and 4)

Damage to leveling compound;

and 5) Cracks; and 6) Etching

or pitting.

Condition 2 -

Hydraulic fluid contamination in its

liquid (fluid), vapor, and/or solid

(coked) form is found.

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Table 1: GVI, DET, and HFEC Inspection of Strut Forward Dry Bay for Hydraulic Fluid Contamination

and Forward Engine Mount Bulkhead for Hydrogen Embrittlement.

Repeat Interval

(Not to Exceed)

Condition Action Compliance Time

1,200 Flight-cycles.Repeat GVI of the interior of the -

strut forward dry bay for hydraulic fluid contamination in its

liquid (fluid), vapor, and/or solid

(coked) form in accordance with

Part 1.

Condition 2A -

1) No hydraulic fluid coking is found;

and

2) No heat discoloration is found;

and

3) No damage to sealant and primer

is found; and

4) No damage to leveling compound

is found; and

5) No crack is found; and

6) No etching or pitting is found.

Do a DET and HFEC of the inte- Before further flight. -

rior of the strut forward engine

mount bulkhead upper and lower fittings for cracks and etching

or pitting in accordance with

Part 3.

Condition 2B -

1) No crack is found; and

2) No etching or pitting is found; and

3) Any of the following is found:

....a) Any Hydraulic fluid coking is

found; or

....b) Any heat discoloration is found;

or

and

Within 25 flight-cy- -

cles or 10 days,

whichever occurs

first, after Condition

2B is found.

Contact The Boeing Company

for repair instructions,do the repair, and restore sealant,

primer, and leveling compound.

....c) Any damage to sealant and

primer is found; or

....d) Any damage to leveling compound is found.

and

1,200 Flight-cycles.Repeat GVI of the interior of the -

strut forward dry bay for hydraulic fluid contamination in its

liquid (fluid), vapor, and/or solid

(coked) form in accordance with

Part 1.

Contact The Boeing Company Before further flight. -

for repair instructions,do the repair, and restore sealant,

primer, and leveling compound.

Condition 2C -

1) Any crack is found; or

2) Any etching or pitting is found.

and

1,200 Flight-cycles.Repeat GVI of the interior of the -

strut forward dry bay for hydraulic fluid contamination in its

liquid (fluid), vapor, and/or solid

(coked) form in accordance with

Part 1.

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BOEING SERVICE BULLETIN 777-54-0028
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.

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 (g) of AD 2013-11-14. All provisions of AD 2013-11-14 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 inspection for each airplane.

This estimate is for direct labor only, done by an experienced crew. Adjust the estimate with operator

task hour data if necessary. The estimate does not include lost time. These are some examples of lost

time:

• Time to adjust to the workplace

• Time to schedule the work

• Time to inspect the work

• Time to cure the materials

• Time to make the parts

• Time to find the tools.

Part 1 - Strut Forward Dry Bay Hydraulic Fluid Contamination GVI Inspection

Task Number of Persons Task Hours Elapsed Hours

Open Access 2 2.00 1.00

Inspect

...FIGURE 1 1 0.50 0.50

...FIGURE 4 1 0.50 0.50

Close Access 2 2.00 1.00

TOTAL FOR EACH AIRPLANE 5.00 3.00

Part 2 - Strut Forward Dry Bay Interior DET Inspection

Task Number of Persons Task Hours Elapsed Hours

Open Access 2 2.00 1.00

Inspect

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Part 2 - Strut Forward Dry Bay Interior DET Inspection

Task Number of Persons Task Hours Elapsed Hours

...FIGURE 2 1 4.00 4.00

...FIGURE 5 1 4.00 4.00

Check Drain Line 2 5.00 2.50

Close Access 2 2.00 1.00

TOTAL FOR EACH AIRPLANE 17.00 12.50

Part 3 - Strut Forward Engine Mount Bulkhead Fitting DET and HFEC Inspection

Task Number of Persons Task Hours Elapsed Hours

Open Access 2 2.00 1.00

Inspect

...FIGURE 3 1 4.00 4.00

...FIGURE 6 1 4.00 4.00

Check Drain Line 2 5.00 2.50

Close Access 2 2.00 1.00

TOTAL FOR EACH AIRPLANE 17.00 12.50

H. Weight and Balance Changes

None.

I. Electrical Load Data

Not changed.

J. References

1. Existing Data:

a. Boeing Service Bulletin 777-54-0027

b. Boeing Service Related Problem (SRP) 777-SRP-54-0138

c. Federal Aviation Administration (FAA) Airworthiness Directive (AD) 2013-11-14

d. Service Bulletin Index D624W001

e. Standard Overhaul Practices Manual (SOPM) 20-30-03, 20-43-03, 20-44-01

f. Standard Wiring Practices Manual (SWPM) 20-10-11, 20-10-12, 20-10-19

g. 777 Aircraft Maintenance Manual (AMM) 06-43-00, 08-21-00, 54-53-01, 54-55-01, 78-31-00

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BOEING SERVICE BULLETIN 777-54-0028
h. 777 Fleet Team Digest (FTD) 54-11001

i. 777 Non-Destructive Testing (NDT) Manual Part 6, 51-00-06

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:

None.

2. Damage Tolerance Based Structural Inspections:

Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue

Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the

Maintenance Program. This service bulletin affects FCS but no new DTIs are necessary.

L. Interchangeability and Intermixability of Parts

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

M. Software Accomplishment Summary

Not affected.

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BOEING SERVICE BULLETIN 777-54-0028

BLANK PAGE
2. MATERIAL INFORMATION

A. Material - Price and Availability

The operator can supply the parts and materials shown in Paragraph 2.C., Parts Necessary for Each

Airplane. As an alternative, operators can purchase the parts from Boeing Spares. This service bulletin

does not show the Boeing price and supply data.

B. Industry Support Information

Boeing warranty remedies are available for 777 airplanes in warranty as of June 15, 2011. For inspection

task hour reimbursement for airplanes in warranty as of that date, send a warranty claim to Boeing

Commercial Airplanes Group - Warranties. If the condition described in this service bulletin is found

during the inspection for airplanes in warranty as of that date and additional task hours are required,

send a warranty claim to Boeing Commercial Airplanes Group - Warranties. Please refer to this service

bulletin number and reference the airplane numbers in your purchase order.

C. Parts Necessary for Each Airplane

1. Kits/Parts

None.

2. Parts and Materials Supplied by the Operator

The following materials may be required to restore the sealant, primer, and leveling compound in

the strut forward dry bay.

Part Number / Specification QTY Name Notes

- 1Oz. Chemical Conversion Coating (c)

BMS 10-79, TYPE III 1 Pt. Primer (a)

BMS 10-11, TYPE I 1 Pt. Primer (a)

BMS 5-63 16 Oz. Sealant (a)

BAC5432, COMPOUND 21, DOW CORNING 1 Pt. Primer, Silicone (d)

1201 RTV PRIME COAT (DOW CORNING PR1200 RTV PRIME COAT RED OR SS4004P

optional)

BAC5432, COMPOUND 21, XIAMETER RTV- 2 Qt. Leveling Compound, Silicone (d)

3110 BASE (DC 3110 OR RTV11 optional)

BAC5432, COMPOUND 21, XIAMETER RTV- 1 Pt. Catalyst (d)

3010-S CATALYST (XIAMETER RTV-3000 F

CATALYST, S TIN NW, OR RTV9950 optional)

SOPM 20-44-01, Type 51 1 Qt. Primer, High Temperature (b)

(a) Refer to the Qualified Products List at the end of the Boeing Material Specification (BMS) for

supplier data.

(b) Refer to SOPM 20-44-01 for supplier data.

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BOEING SERVICE BULLETIN 777-54-0028
Part Number / Specification QTY Name Notes

(c) Refer to SOPM 20-43-03 for supplier data.

(d) See supplier data below. Leveling Compound, Catalyst, and Primer need to come from same

source to ensure compatibility.

– XIAMETER RTV-3110 BASE or DC 3110 (Leveling Compound); XIAMETER RTV-3010-S,

XIAMETER RTV-3000 F, or S TIN NW (Catalyst); and DOW CORNING 1201 RTV PRIME

COAT or DOW CORNING PR-1200 RTV PRIME COAT RED (Primer)

V71984

Dow Corning Corporation

2200 W Salzburg Rd

Midland Mi 48640 - 8531

Customer Service/www.dowcorning.com

(800) 248-248

– RTV11 (Leveling Compound), RTV9950 (catalyst), and SS4004P 01 P (Primer)

V01139

Momentive Performance Materials Inc.

187 Danbury Road

Wilton Ct 06897-4122

www.momentive.com

(704) 992-4107

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 777-54-0028
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. Use the approved fastener and process material substitutions in accordance with

SRM Chapter 51.

4. Refer to the SWPM 20-10-11 and SWPM 20-10-12 for the wire installation procedures,

and SWPM 20-10-19 for the wire separation requirements, as accepted procedures.

5. The necessary conditions for selection of clamp type and size are included in SWPM

20-10-12. If any wire bundle support clamp specified in this service bulletin does not

make a correct fit on the wire bundle, refer to SWPM 20-10-12 as an accepted

procedure to select a clamp that fits correctly.

6. A Detailed Inspection (DET) is defined as: An intensive examination of a specific

item, installation, or assembly to detect damage, failure, or irregularity. Available

lighting is normally supplemented with a direct source of good lighting at an intensity

deemed appropriate. Inspection aids such as mirrors, magnifying lenses, etc. may

be necessary. Surface cleaning and elaborate procedures may be required.

7. A General Visual Inspection (GVI) is defined as: A visual examination of an interior

or exterior area, installation or assembly to detect obvious damage, failure or

irregularity. This level of inspection is made from within touching distance unless

otherwise specified. A mirror may be necessary to enhance visual access to all

exposed surfaces in the inspection area. This level of inspection is made under

normally available lighting conditions such as daylight, hangar lighting, flashlight or

drop-light and may require removal or opening of access panels or doors. Stands,

ladders or platforms may be required to gain proximity to the area being checked.

8. An HFEC inspection is a High Frequency Eddy Current inspection.

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

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

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

accordance with" are included in the instruction, the procedure in the Boeing document

must be used.

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10. The instructions in Paragraph 3.B., Work Instructions and the figures can include

operation of tools or test equipment. Boeing Engineering Tool Drawings, the Illustrated

Tool and Equipment Manual, and the Special Tool and Ground Handling Drawing

Index contain data on versions of the tools or test equipment that you can use. It is

permitted to use replaced tools. It is not permitted to use superseded tools.

11. If it is necessary to remove more parts for access, you can remove those parts. If

you can get access without removing identified parts, it is not necessary to remove

all of the identified parts. Jacking and shoring limitations must be observed.

12. Accomplish the actions and evaluate the conditions separately for each strut forward

dry bay and each forward engine mount bulkhead.

B. WORK INSTRUCTIONS

1. Do a GVI of the interior of the strut forward dry bay for hydraulic fluid contamination in its liquid

(fluid), vapor, and/or solid (coked) form in accordance with Part 1 - Strut Forward Dry Bay Hydraulic

Fluid Contamination GVI Inspection at the compliance time specified in Paragraph 1.E., Compliance.

a. Condition 1 - No hydraulic fluid contamination in its liquid (fluid), vapor, and/or solid (coked)

form is found.

(1) Repeat GVI of the interior of the strut forward dry bay for hydraulic fluid contamination in

its liquid (fluid), vapor, and/or solid (coked) form in accordance with Part 1 - Strut Forward

Dry Bay Hydraulic Fluid Contamination GVI Inspection at the interval specified in Paragraph

1.E., Compliance.

b. Condition 2 - Hydraulic fluid contamination in its liquid (fluid), vapor, and/or solid (coked) form

is found.

(1) Do a DET of the interior of the strut forward dry bay in accordance with Part 2 - Strut

Forward Dry Bay Interior DET Inspection for: 1) Hydraulic fluid coking; and 2) Heat

discoloration; and 3) Damage to sealant and primer; and 4) Damage to leveling compound;

and 5) Cracks; and 6) Etching or pitting at the compliance time specified in Paragraph

1.E., Compliance.

(a) Condition 2A -1) No hydraulic fluid coking is found; and 2) No heat discoloration is

found; and 3) No damage to sealant and primer is found; and 4) No damage to

leveling compound is found; and 5) No crack is found; and 6) No etching or pitting

is found.

1) Repeat GVI of the interior of the strut forward dry bay for hydraulic fluid

contamination in its liquid (fluid), vapor, and/or solid (coked) form in accordance

with Part 1 - Strut Forward Dry Bay Hydraulic Fluid Contamination GVI Inspection

at the interval specified in Paragraph 1.E., Compliance.

(b) Condition 2B - 1) No crack is found; and 2) No etching or pitting is found; and 3) Any

of the following is found: a) Any Hydraulic fluid coking is found; or b) Any heat

discoloration is found; or c) Any damage to sealant and primer is found; or d) Any

damage to leveling compound is found.

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BOEING SERVICE BULLETIN 777-54-0028
1) Do a DET and HFEC of the interior of the strut forward engine mount bulkhead

upper and lower fittings for cracks, and etching or pitting in accordance with Part

3 - Strut Forward Engine Mount Bulkhead Fitting DET and HFEC Inspection, at

the compliance time specified in Paragraph 1.E., Compliance; and

2) Contact The Boeing Company for repair instructions, do the repair, and restore

the sealant, primer, and leveling compound at the compliance time specified in

Paragraph 1.E., Compliance. Refer to APPENDIX A as an accepted procedure

to clean and restore sealant, primer, and leveling compound of the detail parts

in the strut forward dry bay if missing, blistered, peeling, or damaged.

3) Repeat GVI of the interior of the strut forward dry bay for hydraulic fluid

contamination in its liquid (fluid), vapor, and/or solid (coked) form in accordance

with Part 1 - Strut Forward Dry Bay Hydraulic Fluid Contamination GVI Inspection

at the interval specified in Paragraph 1.E., Compliance.

(c) Condition 2C - 1) Any crack is found; or 2) Any etching or pitting is found.

1) Contact The Boeing Company for repair instructions, do the repair, and restore

the sealant, primer, and leveling compound at the compliance time specified in

Paragraph 1.E., Compliance. Refer to APPENDIX A as an accepted procedure

to clean and restore sealant, primer, and leveling compound of the detail parts

in the strut forward dry bay if missing, blistered, peeling, or damaged.

2) Repeat GVI of the interior of the strut forward dry bay for hydraulic fluid

contamination in its liquid (fluid), vapor, and/or solid (coked) form in accordance

with Part 1 - Strut Forward Dry Bay Hydraulic Fluid Contamination GVI Inspection

at the interval specified in Paragraph 1.E., Compliance.

Part 1 - Strut Forward Dry Bay Hydraulic Fluid Contamination GVI Inspection

1. Open the thrust reverser. Refer to 777 AMM 78-31-00 as an accepted procedure.

2. Remove the following access panels. Refer to 777 AMM 06-43-00 and 777 AMM 54-53-01 as

accepted procedures.

Strut No. 1 Strut No. 2

432AR 442AR

3. Do a GVI of the interior of the strut forward dry bay for hydraulic fluid contamination in its liquid

(fluid), vapor, and/or solid (coked) form in accordance with the figure below:

Strut No. 1 Strut No. 2

FIGURE 1 FIGURE 4

4. Install the following access panels. Refer to 777 AMM 06-43-00 and 777 AMM 54-53-01 as accepted

procedures.

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Strut No. 1 Strut No. 2

432AR 442AR

5. Close the thrust reverser. Refer to 777 AMM 78-31-00 as an accepted procedure.

6. Put the airplane back to a serviceable condition.

Part 2 - Strut Forward Dry Bay Interior DET Inspection.

1. Open the thrust reverser. Refer to 777 AMM 78-31-00 as an accepted procedure.

2. Remove the following access panels. Refer to 777 AMM 06-43-00 and 777 AMM 54-53-01 as

accepted procedures.

Strut No. 1 Strut No. 2

432AR 442AR

3. Do a DET of the interior of the strut forward dry bay in accordance with the figure below for: 1)

Hydraulic fluid coking; and 2) Heat discoloration; and 3) Damage to sealant and primer; and 4)

Damage to leveling compound; and 5) Cracks; and 6) Etching or pitting.

NOTE: It is recommended that operators document contamination with pictures and record the

percent of contamination, and whether the lower and/or upper forward engine mount

bulkhead fittings are affected to aid in the development of The Boeing Company repair

instructions.

Strut No. 1 Strut No. 2

FIGURE 2 FIGURE 5

4. Deleted

5. Check drain lines for blockage; Clean or replace drain lines as required. Refer to 777 AMM 54-55-01

as an accepted procedure.

6. Install the following access panels. Refer to 777 AMM 06-43-00 and 777 AMM 54-53-01 as accepted

procedures.

Strut No. 1 Strut No. 2

432AR 442AR

7. Close the thrust reverser. Refer to 777 AMM 78-31-00 as an accepted procedure.

8. Put the airplane back to a serviceable condition.

Part 3 - Strut Forward Engine Mount Bulkhead Fitting DET and HFEC Inspection

1. Open the thrust reverser. Refer to 777 AMM 78-31-00 as an accepted procedure.

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2. Remove the following access panels. Refer to 777 AMM 06-43-00 and 777 AMM 54-53-01 as

accepted procedures.

Strut No. 1 Strut No. 2

432AR 442AR

3. Do a DET and HFEC of the strut forward engine mount bulkhead upper and lower fittings for cracks,

and etching or pitting in accordance with the figure below:

NOTE: It is recommended that operators document contamination with pictures and record the

percent of contamination, and whether the lower and/or upper forward engine mount

bulkhead fittings are affected to aid in the development of The Boeing Company repair

instructions.

Strut No. 1 Strut No. 2

FIGURE 3 FIGURE 6

4. Deleted

5. Check drain lines for blockage; Clean or replace drain lines as required. Refer to 777 AMM 54-55-01

as an accepted procedure.

6. Install the following access panels. Refer to 777 AMM 06-43-00 and 777 AMM 54-53-01 as accepted

procedures.

Strut No. 1 Strut No. 2

432AR 442AR

7. Close the thrust reverser. Refer to 777 AMM 78-31-00 as an accepted procedure.

8. Put the airplane back to a serviceable condition.

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BOEING SERVICE BULLETIN 777-54-0028
FIGURE 1: STRUT NO. 1 - FORWARD DRY BAY INTERIOR - GVI INSPECTION

(SHEET 1 OF 2)

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30 of 49

BOEING SERVICE BULLETIN 777-54-0028
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 one side of the airplane.

Step Task Name Identification Qty More Data

Do a General Visual Inspection (GVI) of the interior of the strut forward dry bay for the presence

of hydraulic fluid contamination in its liquid (fluid),

vapor, and/or solid (coked) form including the

side skins and upper chords and web. The interior is painted with primer. Blistered and/or peeling

primer is a sign that hydraulic fluid contamination

is present and the strut forward dry bay is contaminated.

1 Inspect Strut Fwd Dry Bay - -

FIGURE 1: STRUT NO. 1 - FORWARD DRY BAY INTERIOR - GVI INSPECTION

(SHEET 2 OF 2)

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BOEING SERVICE BULLETIN 777-54-0028
FIGURE 2: STRUT NO. 1 - FORWARD DRY BAY INTERIOR - DET INSPECTION

(SHEET 1 OF 4)

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Revision 1 December 10, 2013 777-54-0028

32 of 49

BOEING SERVICE BULLETIN 777-54-0028
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 one side of the airplane.

Step Task Name Identification Qty More Data

Do a DET of the visible areas in the interior of

the strut forward dry bay for:

Fwd Engine Mount - 1

Bulkhead Upper

Fitting

1 Inspect

1. Hydraulic fluid coking; and

2. Missing, blistered, peeling or damaged

primer; and

3. Heat discoloration; and

4. Cracks; and

5. Etching or pitting.

Clean area, as required, to remove loose dirt,

peeling primer, and any fluids. Refer to SOPM

20-30-03 as an accepted procedure.

Do a DET of the visible areas in the interior of

the strut forward dry bay for:

Fwd Engine Mount - 1

Bulkhead Lower

Fitting

Inspect

1. Hydraulic fluid coking; and

2. Missing, blistered, peeling or damaged

primer; and

3. Heat discoloration; and

4. Cracks; and

5. Etching or pitting.

Clean area, as required, to remove loose dirt,

peeling primer, and any fluids. Refer to SOPM

20-30-03 as an accepted procedure.

Do a DET for damage. Damage is defined as

peeling or disbonding, cracking, and hardening

of the compound. Note: It is normal for the compound to be discolored and stained.

Leveling Com- - -

pound

2 Inspect

FIGURE 2: STRUT NO. 1 - FORWARD DRY BAY INTERIOR - DET INSPECTION

(SHEET 2 OF 4)

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33 of 49

BOEING SERVICE BULLETIN 777-54-0028
Step Task Name Identification Qty More Data

Do a DET of the visible areas in the interior of

the strut forward dry bay for:

Chord / Web - Low- - -

er Spar

3 Inspect

1. Missing, blistered, peeling or damaged

primer; and

2. Cracks; and

3. Etching or pitting.

Clean area, as required, to remove loose dirt,

peeling primer, and any fluids. Refer to SOPM

20-30-03 as an accepted procedure.

Do a DET of the visible areas in the interior of

the strut forward dry bay for:

4 Inspect No. 2 Bulkhead - -

1. Missing, blistered, peeling or damaged

primer; and

2. Cracks; and

3. Etching or pitting.

Clean area, as required, to remove loose dirt,

peeling primer, and any fluids. Refer to SOPM

20-30-03 as an accepted procedure.

Do a DET of the visible areas on both sides of

the interior of the strut forward dry bay for:

5 Inspect Side Skin - -

1. Missing, blistered, peeling or damaged

primer; and

2. Cracks; and

3. Etching or pitting.

Clean area, as required, to remove loose dirt,

peeling primer, and any fluids. Refer to SOPM

20-30-03 as an accepted procedure.

FIGURE 2: STRUT NO. 1 - FORWARD DRY BAY INTERIOR - DET INSPECTION

(SHEET 3 OF 4)

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34 of 49

BOEING SERVICE BULLETIN 777-54-0028
Step Task Name Identification Qty More Data

Do a DET of the visible areas of the top of the

interior of the strut forward dry bay for:

Chord / Web - Up- - -

per Spar

6 Inspect

1. Missing, blistered, peeling or damaged

primer; and

2. Cracks; and

3. Etching or pitting.

Clean area, as required, to remove loose dirt,

peeling primer, and any fluids. Refer to SOPM

20-30-03 as an accepted procedure.

Do a DET for damage in the interior of the strut

forward dry bay. Sealant damage is defined as

breaks in the sealant, cuts, creases and openings, peeling, or it is missing.

7 Inspect Sealant - -

FIGURE 2: STRUT NO. 1 - FORWARD DRY BAY INTERIOR - DET INSPECTION

(SHEET 4 OF 4)

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BOEING SERVICE BULLETIN 777-54-0028
FIGURE 3: STRUT NO. 1 - FORWARD ENGINE MOUNT BULKHEAD FITTING - DET AND HFEC INSPECTION

(SHEET 1 OF 2)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: May 25, 2012

Revision 1 December 10, 2013 777-54-0028

36 of 49

BOEING SERVICE BULLETIN 777-54-0028
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 one side of the airplane.

Step Task Name Identification Qty More Data

Do a DET of the visible areas in the interior of

the strut forward dry bay for:

Fwd Engine Mount - 1

Bulkhead Upper

Fitting

1 Inspect

1. Cracks; and

2. Etching or pitting.

Clean area, as required, to remove loose dirt,

peeling primer, damaged leveling compound,

and any fluids. Refer to SOPM 20-30-03 as an

accepted procedure.

Do a DET of the visible areas in the interior of

the strut forward dry bay for:

Fwd Engine Mount - 1

Bulkhead Lower

Fitting

Inspect

1. Cracks; and

2. Etching or pitting.

Clean area, as required, to remove loose dirt,

peeling primer, and any fluids. Refer to SOPM

20-30-03 as an accepted procedure.

Do a HFEC inspection of the accessible areas

in the interior of the strut forward dry bay for

cracks in the areas where hydraulic fluid coking,

heat discoloration, damage to sealant, missing,

blistered, peeling or damaged primer, and damage to leveling compound was found, in accordance with 777 NDT Part 6, 51-00-06.

Fwd Engine Mount - 1

Bulkhead Upper

Fitting

2 Inspect

Do a HFEC inspection of the accessible areas

in the interior of the strut forward dry bay for

cracks in the areas where hydraulic fluid coking,

heat discoloration, damage to sealant, missing,

blistered, peeling or damaged primer, and damage to leveling compound was found, in accordance with 777 NDT Part 6, 51-00-06.

Fwd Engine Mount - 1

Bulkhead Lower

Fitting

Inspect

FIGURE 3: STRUT NO. 1 - FORWARD ENGINE MOUNT BULKHEAD FITTING - DET AND HFEC INSPECTION

(SHEET 2 OF 2)

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BOEING SERVICE BULLETIN 777-54-0028
FIGURE 4: STRUT NO. 2 - FORWARD DRY BAY INTERIOR - GVI INSPECTION

(SHEET 1 OF 2)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: May 25, 2012

Revision 1 December 10, 2013 777-54-0028

38 of 49

BOEING SERVICE BULLETIN 777-54-0028
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 one side of the airplane.

Step Task Name Identification Qty More Data

Do a General Visual Inspection (GVI) of the interior of the strut forward dry bay for the presence

of hydraulic fluid contamination in its liquid (fluid),

vapor, and/or solid (coked) form including the

side skins and upper chords and web. The interior is painted with primer. Blistered and/or peeling

primer is a sign that hydraulic fluid contamination

is present and the strut forward dry bay is contaminated.

1 Inspect Strut Fwd Dry Bay - -

FIGURE 4: STRUT NO. 2 - FORWARD DRY BAY INTERIOR - GVI INSPECTION

(SHEET 2 OF 2)

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Original Issue: May 25, 2012

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39 of 49

BOEING SERVICE BULLETIN 777-54-0028
FIGURE 5: STRUT NO. 2 - FORWARD DRY BAY INTERIOR - DET INSPECTION

(SHEET 1 OF 4)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: May 25, 2012

Revision 1 December 10, 2013 777-54-0028

40 of 49

BOEING SERVICE BULLETIN 777-54-0028
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 one side of the airplane.

Step Task Name Identification Qty More Data

Do a DET of the visible areas in the interior of

the strut forward dry bay for:

Fwd Engine Mount - 1

Bulkhead Upper

Fitting

1 Inspect

1. Hydraulic fluid coking; and

2. Missing, blistered, peeling or damaged

primer; and

3. Heat discoloration; and

4. Cracks; and

5. Etching or pitting.

Clean area, as required, to remove loose dirt,

peeling primer, and any fluids. Refer to SOPM

20-30-03 as an accepted procedure.

Do a DET of the visible areas in the interior of

the strut forward dry bay for:

Fwd Engine Mount - 1

Bulkhead Lower

Fitting

Inspect

1. Hydraulic fluid coking; and

2. Missing, blistered, peeling or damaged

primer; and

3. Heat discoloration; and

4. Cracks; and

5. Etching or pitting.

Clean area, as required, to remove loose dirt,

peeling primer, and any fluids. Refer to SOPM

20-30-03 as an accepted procedure.

Do a DET for damage. Damage is defined as

peeling or disbonding, cracking, and hardening

of the compound. Note: It is normal for the compound to be discolored and stained.

Leveling Com- - -

pound

2 Inspect

FIGURE 5: STRUT NO. 2 - FORWARD DRY BAY INTERIOR - DET INSPECTION

(SHEET 2 OF 4)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

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Original Issue: May 25, 2012

Revision 1 December 10, 2013 777-54-0028

41 of 49

BOEING SERVICE BULLETIN 777-54-0028
Step Task Name Identification Qty More Data

Do a DET of the visible areas in the interior of

the strut forward dry bay for:

Chord / Web - Low- - -

er Spar

3 Inspect

1. Missing, blistered, peeling or damaged

primer; and

2. Cracks; and

3. Etching or pitting.

Clean area, as required, to remove loose dirt,

peeling primer, and any fluids. Refer to SOPM

20-30-03 as an accepted procedure.

Do a DET of the visible areas in the interior of

the strut forward dry bay for:

4 Inspect No. 2 Bulkhead - -

1. Missing, blistered, peeling or damaged

primer; and

2. Cracks; and

3. Etching or pitting.

Clean area, as required, to remove loose dirt,

peeling primer, and any fluids. Refer to SOPM

20-30-03 as an accepted procedure.

Do a DET of the visible areas on both sides of

the interior of the strut forward dry bay for:

5 Inspect Side Skin - -

1. Missing, blistered, peeling or damaged

primer; and

2. Cracks; and

3. Etching or pitting.

Clean area, as required, to remove loose dirt,

peeling primer, and any fluids. Refer to SOPM

20-30-03 as an accepted procedure.

FIGURE 5: STRUT NO. 2 - FORWARD DRY BAY INTERIOR - DET INSPECTION

(SHEET 3 OF 4)

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Original Issue: May 25, 2012

Revision 1 December 10, 2013 777-54-0028

42 of 49

BOEING SERVICE BULLETIN 777-54-0028
Step Task Name Identification Qty More Data

Do a DET of the visible areas of the top of the

interior of the strut forward dry bay for:

Chord / Web - Up- - -

per Spar

6 Inspect

1. Missing, blistered, peeling or damaged

primer; and

2. Cracks; and

3. Etching or pitting.

Clean area, as required, to remove loose dirt,

peeling primer, and any fluids. Refer to SOPM

20-30-03 as an accepted procedure.

Do a DET for damage in the interior of the strut

forward dry bay. Sealant damage is defined as

breaks in the sealant, cuts, creases and openings, peeling, or it is missing.

7 Inspect Sealant - -

FIGURE 5: STRUT NO. 2 - FORWARD DRY BAY INTERIOR - DET INSPECTION

(SHEET 4 OF 4)

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BOEING SERVICE BULLETIN 777-54-0028
FIGURE 6: STRUT NO. 2 - FORWARD ENGINE MOUNT BULKHEAD FITTING - DET AND HFEC INSPECTION

(SHEET 1 OF 2)

Export Controlled ECCN: 9E991 - BOEING

PROPRIETARY - Copyright © Unpublished

Work - See page 1 for details.

Original Issue: May 25, 2012

Revision 1 December 10, 2013 777-54-0028

44 of 49

BOEING SERVICE BULLETIN 777-54-0028
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 one side of the airplane.

Step Task Name Identification Qty More Data

Do a DET of the visible areas in the interior of

the strut forward dry bay for:

Fwd Engine Mount - 1

Bulkhead Upper

Fitting

1 Inspect

1. Cracks; and

2. Etching or pitting.

Clean area, as required, to remove loose dirt,

peeling primer, damaged leveling compound,

and any fluids. Refer to SOPM 20-30-03 as an

accepted procedure.

Do a DET of the visible areas in the interior of

the strut forward dry bay for:

Fwd Engine Mount - 1

Bulkhead Lower

Fitting

Inspect

1. Cracks; and

2. Etching or pitting.

Clean area, as required, to remove loose dirt,

peeling primer, and any fluids. Refer to SOPM

20-30-03 as an accepted procedure.

Do a HFEC inspection of the accessible areas

in the interior of the strut forward dry bay for

cracks in the areas where hydraulic fluid coking,

heat discoloration, damage to sealant, missing,

blistered, peeling or damaged primer, and damage to leveling compound was found, in accordance with 777 NDT Part 6, 51-00-06.

Fwd Engine Mount - 1

Bulkhead Upper

Fitting

2 Inspect

Do a HFEC inspection of the accessible areas

in the interior of the strut forward dry bay for

cracks in the areas where hydraulic fluid coking,

heat discoloration, damage to sealant, missing,

blistered, peeling or damaged primer, and damage to leveling compound was found, in accordance with 777 NDT Part 6, 51-00-06.

Fwd Engine Mount - 1

Bulkhead Lower

Fitting

Inspect

FIGURE 6: STRUT NO. 2 - FORWARD ENGINE MOUNT BULKHEAD FITTING - DET AND HFEC INSPECTION

(SHEET 2 OF 2)

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BOEING SERVICE BULLETIN 777-54-0028
APPENDIX A: CLEANING AND REFINISHING OF STRUT FWD DRY BAY DETAILS

(SHEET 1 OF 4)

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BOEING SERVICE BULLETIN 777-54-0028
APPENDIX A: CLEANING AND REFINISHING OF STRUT FWD DRY BAY DETAILS

(SHEET 2 OF 4)

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Original Issue: May 25, 2012

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BOEING SERVICE BULLETIN 777-54-0028
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 one side of the airplane.

NOTE: When cleaning, do not use solvents which contain chlorinated hydrocarbons. This can result

in hydrogen embrittlement of the titanium parts when the parts enter service and are exposed

to heat. Refer to SOPM 20-30-03 as an accepted procedure.

1.

2. If leveling compound is being applied, level airplane. Refer to 777 AMM 08-21-00 as an

accepted procedure. Leveling the airplane is not required if repairing small damaged areas,

1 square inch or less, with sealant.

Step Task Name Identification Qty More Data

Not Shown. Solvent clean the interior of

surfaces of the strut forward dry bay

area, as required. Refer to SOPM 20-30-

03 as an accepted procedure.

1 Clean Strut Fwd Dry Bay - -

To the aluminum No. 2 Bulkhead Assembly and the Side Skins only. Refer to

SOPM 20-43-03, Type 2, class A as an

accepted procedure.

Chemical Conver- - -

sion Coating

2 Apply

Apply one coat. Cure at room temperature.SOPM 20-44-01, Type -

51

Primer, High Temperature3 Apply

Apply two coats. Upper spar chord and

web.

4 Apply Primer BMS 10-11, TYPE I

5 Apply Primer BMS 10-79, TYPE III Apply one coat. Side skin.

6 Apply Sealant BMS 5-63 - Restore fillet seals as required.

Leveling Com- - - Remove damaged leveling compound.

pound

7 Remove

Apply primer to the bare surfaces where

leveling compound will be applied. This

will ensure proper adhesion of the leveling compound. Not required if doing optional sealant repair in step applying the

leveling compound below.

BAC 5432, COM- -

POUND 21, DOW

CORNING 1201 RTV

PRIME COAT (DOW

CORNING PR-1200

RTV PRIME COAT

RED OR SS4004P optional)

Apply Primer, Silicone

APPENDIX A: CLEANING AND REFINISHING OF STRUT FWD DRY BAY DETAILS

(SHEET 3 OF 4)

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BOEING SERVICE BULLETIN 777-54-0028
Step Task Name Identification Qty More Data

Mix with catalyst in accordance with the

manufacturer's instructions to form the

leveling compound. Not required if doing

optional sealant repair in step applying

the leveling compound below.

BAC 5432, COM- -

POUND 21, COMPOUND 21, XIAMETER RTV-3110 BASE

(DC 3110 OR RTV11

optional)

Leveling Compound, Silicone8 Make

Mix with silicone in accordance with the

manufacturer's instructions to form the

leveling compound. Not required if doing

optional sealant repair in step applying

the leveling compound below.

BAC 5432, COM- -

POUND 21, XIAMETER RTV-3010-S CATALYST (XIAMETER

RTV-3000 F CATALYST, S TIN NW, OR

RTV9950 optional)

Make Catalyst

Pour the leveling compound into the

forward corners, until it is level with the

bottom of the fitting or drain hole. Do not

block drain hole. Not required if doing

optional sealant repair below.

Leveling Com- - -

pound

9 Apply

Optional for areas that are 1 square inch or less.

Leveling airplane is not required if using this method.

Apply Sealant BMS 5-63 - Smooth into existing leveling compound.

APPENDIX A: CLEANING AND REFINISHING OF STRUT FWD DRY BAY DETAILS

(SHEET 4 OF 4)

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BOEING SERVICE BULLETIN 777-54-0028