# Boeing Special Attention Service Bulletin 777-25-0621: Revision 1

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- Document: [Boeing Special Attention Service Bulletin 777-25-0621](https://openairdocs.org/service-documents/boeing/sb-777-25-0621.md)
- Title as filed: SB-777-25-0621 Rev01
- Pages: 65
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## Text

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### Page 1

Commercial 
Airplanes
777
Service Bulletin
SPECIAL ATTENTION
Number: 777-25-0621
Original Issue: December 10, 2014
Revision 1: August 04, 2017
ATA System: 2510 2581
SUBJECT: EQUIPMENT/FURNISHINGS - Flight Compartment - Overhead Panel Support Structure
BMS 8-39 Urethane Foam Insulation Replacement
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.
9E991ECCN:
BOEING PROPRIETARY, CONFIDENTIAL AND/OR TRADE SECRET
Copyright © 2014 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Unpublished Work.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.
Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, Dreamliner,
BBJ, DC-8, DC-9, DC-10, KC-10, KC-46, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8, Poseidon and
Boeing liveries 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.
Original Issue: December 10, 2014
777-25-0621Revision 1: August 04, 2017
1 of 65
2.0

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Original Issue: December 10, 2014
777-25-0621Revision 1: August 04, 2017
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Table of Contents
Revision Transmittal Sheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1. PLANNING INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
A. Effectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
1. Airplanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
B. Concurrent Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
C. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
E. Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
C. Parts Necessary for Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
1. Kits/Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2. Parts and Materials Supplied by the Operator . . . . . . . . . . . . . . . . . . . . . . . . 25
3. Parts Modified and Reidentified . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
4. Parts Removed and Not Replaced . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
D. Parts Necessary to Change Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
E. Special Tooling - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
F. Special Tooling Necessary to do this Service Bulletin . . . . . . . . . . . . . . . . . . . . . . . 26
3. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
B. WORK INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
FIGURE 1: FLIGHT COMPARTMENT - OVERHEAD PANEL - OPEN ACCESS . . . . . . . . . . . . 32
FIGURE 2: FLIGHT COMPARTMENT - OVERHEAD PANEL SUPPORT STRUCTURE, BMS 8-39
URETHANE FOAM INSULATION REPLACEMENT  [Group 1, Configuration 1] . . . . . . 37
FIGURE 3: FLIGHT COMPARTMENT - OVERHEAD PANEL - CLOSE ACCESS . . . . . . . . . . . 40
FIGURE 4: FLIGHT COMPARTMENT - OVERHEAD PANEL SUPPORT STRUCTURE - REMOVAL . 45
FIGURE 5: FLIGHT COMPARTMENT - OVERHEAD PANEL SUPPORT STRUCTURE - INSTALLATION
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
FIGURE 6: FLIGHT COMPARTMENT - OVERHEAD PANEL - OPEN ACCESS [Group 1, Configuration 2]
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
FIGURE 7: FLIGHT COMPARTMENT - DRIPSHIELD, BMS 8-39 URETHANE FOAM INSULATION -
GENERAL VISUAL INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Export Controlled ECCN: 9E991 - BOEING
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Original Issue: December 10, 2014
777-25-0621Revision 1: August 04, 2017
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FIGURE 8: FLIGHT COMPARTMENT - DRIPSHIELD, BMS 8-39 URETHANE FOAM INSULATION -
REPLACEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
FIGURE 9: FLIGHT COMPARTMENT - OVERHEAD PANEL - CLOSE ACCESS [Group 1, Configuration
2] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
APPENDIX A: PART DEMAND INTENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
APPENDIX B: LOGIC DIAGRAM FOR PARAGRAPH 1.E., COMPLIANCE: TABLE 1: OVERHEAD PANEL
SUPPORT STRUCTURE BMS 3-89 URETHANE FOAM INSULATION INSPECTION AND
REPLACEMENT [Group 1, Configuration 1] . . . . . . . . . . . . . . . . . . . . . . . . . 62
APPENDIX C: LOGIC DIAGRAM FOR PARAGRAPH 1.E., COMPLIANCE: TABLE 2: GENERAL VISUAL
INSPECTION OF THE DRIPSHIELD, ABOVE THE OVERHEAD PANEL SUPPORT
STRUCTURE, FOR BMS 8-39 FOAM INSULATION  [Group 1, Configuration 2] . . . . . . 63
APPENDIX D: TYPICAL INSTALLATIONS OF BMS 8-39 URETHANE FOAM INSULATION INSTALLED ON
THE DRIPSHIELD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Export Controlled ECCN: 9E991 - BOEING
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Commercial 
Airplanes
777
Service Bulletin
SPECIAL ATTENTION
Revision Transmittal SheetNumber: 777-25-0621Original Issue: December 10, 2014
Revision 1: August 04, 2017
ATA System: 2510 2581
SUBJECT: EQUIPMENT/FURNISHINGS - Flight Compartment - Overhead Panel Support Structure
BMS 8-39 Urethane Foam Insulation Replacement
This revision includes all pages of the service bulletin.
COMPLIANCE INFORMATION RELATED TO THIS REVISION
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.
Effects of this Revision on airplanes on which the Original issue was previously done:
ActionConditionGroup
Do a General Visual Inspection (GVI) for
BMS 8-39 urethane foam insulation on the
dripshield, above the overhead panel support
structure. If found replace with BMS 8-371
polyvinylidene fluoride foam insulation.
Airplanes that have replaced BMS 8-39 ure-
thane foam insulation with BMS 8-371
polyvinylidene fluoride foam insulation on
the overhead panel support structure.
1
REASON FOR REVISION
This revision is sent to incorporate results from the service bulletin validation. The validation found that foam
insulation replacement could not be done without the removal of the overhead panel support structure from the
flight compartment ceiling. Removal and installation instructions are added to this service bulletin. This revision
also adds work instructions which includes tests of modules and a General Visual Inspection (GVI) of the
dripshield for BMS 8-39 urethane foam insulation.
As a part of a service bulletin validation program, this change was completed on airplane WB509 by Service
Bulletin 777-25-0621 Original Issue before the release of Revision 1 of this service bulletin. The change completed
on airplane WB509 by Service Bulletin 777-25-0621 Original Issue is equivalent to the release of Revision 1 of
this service bulletin. Airplane WB509 has the configuration of a Group 1 airplane.
These sections were changed:
1. Summary, Background: Changed to add service bulletin validation information. Summary Evaluation
Table changed to add AD related.
2. Summary, Action: Added applicability. Changed and added instructions.
Export Controlled ECCN: 9E991 - BOEING
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3. Summary, Compliance: Added possible FAA AD activity for this service bulletin.
4. Summary, Illustration: Added information.
5. Paragraph 1.C., Reason: Added validation information and Revision 1 information.
6. Paragraph 1.D., Description: Added applicability. Changed and added instructions. Added Revision 1
information.
7. Paragraph 1.E., Compliance: Added information and tables.
8. Paragraph 1.G., Manpower: Added applicability. Changed to show information for Part 1, 2, 3 and 4.
9. Paragraph 1.J.1., Existing Data: Added 777 Aircraft Maintenance Manual (AMM), Standard Overhaul
Practices Manual (SOPM) and Standard Wiring Practices Manual (SWPM) references.
10. Paragraph 1.J.3., Installation Drawings Used in Preparation of this Service Bulletin: Added drawing.
11. Paragraph 1.K.1., Publications: Added Illustrated Parts Catalog (IPC) references. Added affected
section of the Aircraft Maintenance Manual (AMM).
12. Paragraph 2.A., Material - Price and Availability: Added applicability. Changed ROLT, Pricing and
added self-locking nut part number BACN11AG4.
13. Paragraph 2.C.1., Kits/Parts: Added applicability. Added part.
14. Paragraph 2.C.2., Parts and Materials Supplied by the Operator: Added material.
15. Paragraph 2.C.3., Parts Modified and Reidentified: Added applicability. Changed information.
16. Paragraph 3.A., General Information: Added notes.
17. Paragraph 3.B., Work Instructions: Changed to put instructions into Parts 1, 2, 3 and 4.
18. Figure 1: Changed figure title. Changed module titles and added AMM reference. Added instructions
to remove modules and to disconnect electrical connectors and wiring.
19. Figure 2: Changed figure title and added applicability. Changed illustration. Added more instruction to
better describe foam insulation bonding procedure. Changed step table and footnote (c).
20. Figure 3: Changed figure title. Changed module title and added AMM reference. Added instructions to
add modules and to connect electrical connectors and wiring.
21. Figure 4 thru Figure 9: Added New Figures
22. Appendix B, Appendix C and Appendix D: Added New Appendices.
Vertical lines are put on the left edge of each page, except in Paragraph 1.A., Effectivity and format changes,
to show the location of all content changes.
Pages with no vertical lines have no changes.
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REVISION HISTORY
December 10, 2014Original Issue:
August 04, 2017Revision 1:
Export Controlled ECCN: 9E991 - BOEING
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777-25-0621Revision 1: August 04, 2017
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Commercial 
Airplanes
777
Service Bulletin
SPECIAL ATTENTION
SummaryNumber: 777-25-0621Original Issue: December 10, 2014
Revision 1: August 04, 2017
ATA System: 2510 2581
SUBJECT: EQUIPMENT/FURNISHINGS - Flight Compartment - Overhead Panel Support Structure
BMS 8-39 Urethane Foam Insulation Replacement
BOEING RECOMMENDS THAT EACH OPERATOR EXAMINE THIS DOCUMENT IMMEDIATELY.
CONCURRENT REQUIREMENTS
None.
BACKGROUND
Accomplishment of this service bulletin will make sure that the risk of fire in the flight compartment from aging
BMS 8-39 urethane foam insulation is decreased. Degraded BMS 8-39 urethane foam insulation on the overhead
panel support structure can be an unacceptable fuel source for a fire if exposed to an ignition source. If this
service bulletin is not done, degraded BMS 8-39 urethane foam insulation could result in an increased risk of a
fire.
BMS 8-39 flexible urethane foam insulation has self-extinguishing and physical properties that degrade with age
and large parts fabricated from this material present an unacceptable fuel source. BMS 8-39 urethane foam
insulation fire retardants are mixed into, but are not chemically connected with, the remaining components of
the foam insulation. This condition will cause the fire retardant properties to have decreased effectiveness. The
concern is hidden areas where fire cannot easily be detected and suppressed.
BMS 8-39 urethane foam insulation in the flight compartment and other areas of the airplanes was replaced in
production from line number 507 and Boeing Service Bulletin 777-25-0362 was released to instruct foam insulation
replacement for in-service airplanes. However, Boeing has recently found some additional BMS 8-39 urethane
foam insulation on the overhead panel support structure in the flight compartment, that was not included in
Boeing Service Bulletin 777-25-0362.
Since the release of the Original Issue of this service bulletin, BMS 8-39 urethane foam insulation was found
on the dripshield above the overhead panel. All BMS 8-39 urethane foam insulation on the overhead panel and
if installed on the dripshield, must be removed and replaced with BMS 8-371 polyvinylidene fluoride foam
insulation. This service bulletin gives instructions to remove BMS 8-39 urethane foam insulation and install BMS
8-371 polyvinylidene fluoride foam insulation on the overhead panel support structure in the flight compartment.
BMS 8-371 polyvinylidene fluoride foam insulation has better fire retardant properties that stay effective with
age.
Boeing Service Related Problem (SRP) 777-SRP-25-0346 is related to this service bulletin.
Boeing Fleet Team Digest (FTD) 777 FTD 25-14003 is related to this service bulletin.
Export Controlled ECCN: 9E991 - BOEING
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As a part of a service bulletin validation program, this change was completed on airplane WB509 by Service
Bulletin 777-25-0621 Original Issue before the release of Revision 1 of this service bulletin. The change completed
on airplane WB509 by Service Bulletin 777-25-0621 Original Issue is equivalent to the release of Revision 1 of
this service bulletin. Airplane WB509 has the configuration of a Group 1 airplane.
This table is provided to operators for planning purposes only. Refer to the applicable sections for more
information.
ReferenceAffectedPlanning Data
Paragraph 1.A.2., Spares AffectedNoSpares Affected
Paragraph 1.E., ComplianceYesAD Related
Paragraph 1.H., Weight and Balance ChangesNoWeight and Balance Change
Paragraph 1.I., Electrical Load DataNoElectrical Load Changed
Paragraph 1.K., Publications AffectedYesPublications Affected
Paragraph 1.K., Publications AffectedNoAirplane Flight Operations Affected
(Flight Crew Operations Manual and/or
FAA Approved Airplane Flight Manual)
Paragraph 2.C.1., Kits/PartsYesKits/Parts Required
Paragraph 2.C.2., Parts and Materials Supplied
by the Operator
YesOperator Supplied Parts/Material
Paragraph 2.F., Special Tooling Necessary to
do this Service Bulletin
NoSpecial Tooling Required
ACTION
Group 1, Configuration 1:
Replace BMS 8-39 urethane foam insulation with BMS 8-371 polyvinylidene fluoride foam insulation on the
overhead panel support structure in the flight compartment. Do a General Visual Inspection of the dripshield,
above the overhead panel support structure, for BMS 8-39 urethane foam insulation and do corrective actions.
Group 1, Configuration 2:
Do a General Visual Inspection of the dripshield, above the overhead panel support structure, for BMS 8-39
urethane foam insulation and do corrective actions.
Do the tests of the modules in the overhead panel.
EFFECTIVITY
777-200/200LR/300/300ER Airplanes. 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.
Refer to Paragraph 1.E., Compliance.
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INDUSTRY SUPPORT INFORMATION
Boeing warranty remedies are not available for the configuration changes given in this service bulletin.
MANPOWER
Refer to Paragraph 1.G., Manpower.
MATERIAL INFORMATION
Boeing Supplied Kits/Parts.
Refer to Paragraph 2.A., Material - Price and Availability.
Operators are encouraged to complete the survey provided in APPENDIX A of this service bulletin to help Boeing
predict the quantity and timing of the Boeing Supplied Kits/Parts.
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BOEING SERVICE BULLETIN 777-25-0621
GROUP 1, CONFIGURATION 1:
REPLACE BMS 8-39 URETHANE FOAM INSULATION
WITH BMS 8-371 POLYVINYLDENE FLUORIDE
FOAM INSULATION ON THE OVERHEAD PANEL
SUPPORT STRUCTURE.
DO A GENERAL VISUAL INSPECTION OF THE
DRIPSHIELD, ABOVE THE OVERHEAD PANEL
SUPPORT STRUCTURE, FOR BMS 8-39 URETHANE
FOAM INSULATION AND DO CORRECTIVE
ACTIONS. TEST MODULES.
GROUP 1, CONFIGURATION 2:
DO A GENERAL VISUAL INSPECTION OF THE
DRIPSHIELD, ABOVE THE OVERHEAD PANEL
SUPPORT STRUCTURE, FOR BMS 8-39 URETHANE
FOAM INSULATION AND DO CORRECTIVE
FLIGHT COMPARTMENT  ACTIONS. TEST MODULES.
OVERHEAD PANEL SUPPORT STRUCTURE  2376182
(WIRE BUNDLES AND MODULES NOT SHOWN)
Original Issue: December 10, 2014
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### Page 13

Commercial 
Airplanes
777
Service Bulletin
SPECIAL ATTENTION
Number: 777-25-0621
Original Issue: December 10, 2014
Revision 1: August 04, 2017
ATA System: 2510 2581
SUBJECT: EQUIPMENT/FURNISHINGS - Flight Compartment - Overhead Panel Support Structure
BMS 8-39 Urethane Foam Insulation Replacement
BOEING RECOMMENDS THAT EACH OPERATOR EXAMINE THIS DOCUMENT IMMEDIATELY.
1.    PLANNING INFORMATION
A. Effectivity
1. Airplanes
Refer to Service Bulletin Index D624W001 Part 3 for Airplane Variable Number, Line Number, and
Serial Number data.
This service bulletin is applicable to 777-200/200LR/300/300ER Airplanes, line numbers 1-506,
in 1 Group. The Variable Numbers and Group Information for the applicable airplanes is given
below.
DESCRIPTIONCONFIGURATIONGROUP
777-200/-200LR/-300/-300ER Aiplanes that have BMS 8-39 urethane
foam insulation installed on the overhead support structure in the
flight compartment.
-1
Airplanes that have not accomplished the Original Issue of this service
bulletin.
1
Airplanes that have accomplished the Original Issue of this service
bulletin.
2
Airplane Models:
777-200, 777-200LR, 777-300, 777-300ER
GroupVariable Number
1WA001 - WA017
1WA076 - WA080
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GroupVariable Number
1WA086 - WA093
1WA101 - WA104
1WA116 - WA119
1WA131 - WA137
1WA171 - WA175
1WA196 - WA198
1WA206 - WA212
1WA221 - WA223
1WA231 - WA232
1WA241 - WA250
1WA261 - WA266
1WA281
1WA301 - WA302
1WB001 - WB021
1WB031 - WB046
1WB051 - WB088
1WB101 - WB106
1WB121 - WB125
1WB131 - WB139
1WB151 - WB155
1WB161 - WB177
1WB181 - WB194
1WB201 - WB215
1WB231 - WB247
1WB271 - WB273
1WB276 - WB286
1WB291 - WB302
1WB306 - WB307
1WB311 - WB337
1WB341 - WB342
1WB366 - WB367
1WB371 - WB388
1WB406
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GroupVariable Number
1WB411 - WB413
1WB416 - WB437
1WB446 - WB453
1WB476
1WB481 - WB484
1WB501 - WB510
1WB531 - WB537
1WB551 - WB554
1WB591 - WB597
1WB601 - WB606
1WB611 - WB621
1WB631 - WB638
1WB646 - WB649
1WC051 - WC073
1WC101 - WC104
1WC111 - WC115
1WC241 - WC243
1WC281 - WC290
1WC301 - WC306
1WC361 - WC362
1WC371 - WC374
1WC381 - WC390
1WC441
1WC446 - WC448
1WC456
1WD001
1WD501 - WD502
1WD521 - WD529
1WD561
1WD621
2. Spares Affected
None.
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B. Concurrent Requirements
None.
C. Reason
Accomplishment of this service bulletin will make sure that the risk of fire in the flight compartment from
aging BMS 8-39 urethane foam insulation is decreased. Degraded BMS 8-39 urethane foam insulation
on the overhead panel support structure can be an unacceptable fuel source for a fire if exposed to an
ignition source. If this service bulletin is not done, degraded BMS 8-39 urethane foam insulation could
result in an increased risk of a fire.
BMS 8-39 flexible urethane foam insulation has self-extinguishing and physical properties that degrade
with age and large parts fabricated from this material present an unacceptable fuel source. BMS 8-39
urethane foam insulation fire retardants are mixed into, but are not chemically connected with, the
remaining components of the foam insulation. This condition will cause the fire retardant properties to
have decreased effectiveness. The concern is hidden areas where fire cannot easily be detected and
suppressed.
BMS 8-39 urethane foam insulation in the flight compartment and other areas of the airplanes was
replaced in production from line number 507 and Boeing Service Bulletin 777-25-0362 was released
to instruct foam insulation replacement for in-service airplanes. However, Boeing has recently found
some additional BMS 8-39 urethane foam insulation on the overhead panel support structure in the
flight compartment, that was not included in Boeing Service Bulletin 777-25-0362.
Since the release of the Original Issue of this service bulletin, BMS 8-39 urethane foam insulation was
found on the dripshield above the overhead panel. All BMS 8-39 urethane foam insulation on the
overhead panel and if installed on the dripshield, must be removed and replaced with BMS 8-371
polyvinylidene fluoride foam insulation. This service bulletin gives instructions to remove BMS 8-39
urethane foam insulation and install BMS 8-371 polyvinylidene fluoride foam insulation on the overhead
panel support structure in the flight compartment. BMS 8-371 polyvinylidene fluoride foam insulation
has better fire retardant properties that stay effective with age.
Boeing Service Related Problem (SRP) 777-SRP-25-0346 is related to this service bulletin.
Boeing Fleet Team Digest (FTD) 777 FTD 25-14003 is related to this service bulletin.
As a part of a service bulletin validation program, this change was completed on airplane WB509 by
Service Bulletin 777-25-0621 Original Issue before the release of Revision 1 of this service bulletin.
The change completed on airplane WB509 by Service Bulletin 777-25-0621 Original Issue is equivalent
to the release of Revision 1 of this service bulletin. Airplane WB509 has the configuration of a Group
1 airplane.
Revision 1 is sent to incorporate results from the service bulletin validation. The validation found that
foam insulation replacement could not be done without the removal of the overhead panel support
structure from the flight compartment ceiling. Removal and installation instructions are added to this
service bulletin. This revision also adds work instructions which includes tests of modules and a General
Visual Inspection (GVI) of the dripshield for BMS 8-39 urethane foam insulation.
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D. Description
Group 1, Configuration 1:
Replace BMS 8-39 urethane foam insulation with BMS 8-371 polyvinylidene fluoride foam insulation
on the overhead panel support structure in the flight compartment. Do a General Visual Inspection of
the dripshield, above the overhead panel support structure, for BMS 8-39 urethane foam insulation
and do corrective actions.
Group 1, Configuration 2:
Do a General Visual Inspection of the dripshield, above the overhead panel support structure, for BMS
8-39 urethane foam insulation and do corrective actions.
Do the tests of the modules in the overhead panel.
Effects of this Revision on airplanes on which the Original Issue was previously done:
ActionConditionGroup
Do a General Visual Inspection (GVI) for
BMS 8-39 urethane foam insulation on the
dripshield, above the overhead panel support
structure. If found replace with BMS 8-371
polyvinylidene fluoride foam insulation.
Airplanes that have replaced BMS 8-39 ure-
thane foam insulation with BMS 8-371
polyvinylidene fluoride foam insulation on
the overhead panel support structure.
1
The work in this service bulletin is done in the maintenance zone(s) given below.
Affected Maintenance Zones
ZoneModel
211, 212777-200, 777-200LR, 777-300,
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.
Do the required actions in accordance with Paragraph 3. Accomplishment Instructions.
A logic diagram showing compliance tasks and compliance times is included as an aid in APPENDIX
B and APPENDIX C.
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Group 1, Configuration 1:
Table 1: OVERHEAD PANEL SUPPORT STRUCTURE BMS 8-39 URETHANE FOAM INSULATION
INSPECTION AND REPLACEMENT
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
-Within 72 months
after the Original
Issue date of this
service bulletin.
Do PART 1: OVERHEAD
PANEL SUPPORT
STRUCTURE BMS 8-39
URETHANE FOAM INSU-
LATION REPLACEMENT
All airplanes
Do PART 2: GENERAL
VISUAL INSPECTION
OF THE DRIPSHIELD
--No further action re-
quired.
CONDITION 1: BMS 8-39
URETHANE FOAM INSU-
LATION IS NOT FOUND
ON THE DRIPSHIELD
-Before further
flight.
Do PART 3: DRIP-
SHIELD BMS 8-39 URE-
THANE FOAM INSULA-
TION REPLACEMENT
CONDITION 2: BMS 8-39
URETHANE FOAM INSU-
LATION IS FOUND ON
THE DRIPSHIELD
Group 1, Configuration 2:
Table 2: GENERAL VISUAL INSPECTION OF THE DRIPSHIELD, ABOVE THE OVERHEAD PANEL
SUPPORT STRUCTURE, FOR BMS 8-39 URETHANE FOAM INSULATION
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
-Within 72 months
after the Original
Issue date of this
service bulletin.
Do PART 2: GENERAL
VISUAL INSPECTION
OF THE DRIPSHIELD
All airplanes
--No further action re-
quired.
CONDITION 1: BMS 8-39
URETHANE FOAM INSU-
LATION IS NOT FOUND
ON THE DRIPSHIELD
-Before further
flight.
Do PART 3: DRIP-
SHIELD BMS 8-39 URE-
THANE FOAM INSULA-
TION REPLACEMENT
CONDITION 2: BMS 8-39
URETHANE FOAM INSU-
LATION IS FOUND ON
THE DRIPSHIELD
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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 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.
Group 1, Configuration 1:
OVERHEAD PANEL SUPPORT STRUCTURE BMS 8-39 URETHANE FOAM INSULATION INSPEC-
TION AND REPLACEMENT
Elapsed HoursTask HoursNumber of PersonsTask
1.002.002Open Access
1.853.702FIGURE 1
1.252.502FIGURE 4
3.757.502FIGURE 2
0.250.251FIGURE 7
1.503.002FIGURE 8(a)
1.252.502FIGURE 5
3.156.302FIGURE 3
2.304.602Test
1.002.002Close Access
15.8031.35TOTAL FOR EACH AIRPLANE
(a) Add the value of this task to the total for each airplane if BMS 8-39 urethane foam insu-
lation is found installed on the dripshield.
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Group 1, Configuration 2:
GENERAL VISUAL INSPECTION OF THE DRIPSHIELD, ABOVE THE OVERHEAD PANEL SUPPORT
STRUCTURE, FOR BMS 8-39 URETHANE FOAM INSULATION
Elapsed HoursTask HoursNumber of PersonsTask
1.002.002Open Access
1.501.501FIGURE 6
0.250.251FIGURE 7
1.501.501FIGURE 9
1.853.702FIGURE 1(a)
1.252.502FIGURE 4(a)
1.503.002FIGURE 8(a)
1.252.502FIGURE 5(a)
3.156.302FIGURE 3(a)
2.304.602Test
1.002.002Close Access
7.5511.85TOTAL FOR EACH AIRPLANE
(a) Add the value of these tasks to the total for each airplane if BMS 8-39 urethane foam
insulation is found installed on the dripshield.
H. Weight and Balance Changes
None.
I. Electrical Load Data
Not changed.
J. References
1. Existing Data:
a. Boeing Service Bulletin 777-25-0362
b. Boeing Service Related Problem (SRP) 777-SRP-25-0346
c. Service Bulletin Index D624W001
d. Standard Overhaul Practices Manual (SOPM) 20-11-03, 20-30-03, 20-50-10
e. Standard Wiring Practices Manual (SWPM) 20-10-11, 20-10-12, 20-10-19
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f. 777 Aircraft Maintenance Manual (AMM) 21-44-09, 21-60-01, 23-24-03, 23-71-02, 23-71-04,
23-92-02, 24-22-00, 24-22-01, 25-15-06, 26-16-00, 26-22-03, 26-22-04, 27-02-03, 27-02-32,
28-22-17, 29-11-80, 30-11-00, 30-21-00, 30-41-02, 30-41-12, 30-42-00, 33-11-00, 33-42-00,
36-11-10, 49-11-00, 73-00-00, 73-21-00
g. 777 Fleet Team Digest (FTD) 25-14003
2. Data Supplied with this Service Bulletin:
None.
3. Installation Drawings Used in the Preparation of this Service Bulletin:
TitleDrawing Number
SUPPORT INSTL-OVERHEAD PANEL233W3300
The table above lists applicable drawings used to prepare this service bulletin. The drawings are
not necessary to make the specified changes, and are not supplied with this service bulletin. The
drawings may not be applicable to all airplane configurations or operators.
K. Publications Affected
1. Publications:
Chapter-SectionPublication
21-22, 25-10, 33-11777 Illustrated Parts Catalog
53-17777 Aircraft Maintenance Manual - Prac-
tices and Procedures
2. Damage Tolerance Based Structural Inspections:
Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue
Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the
Maintenance Program. This service bulletin does not affect FCS, therefore DTIs are not necessary.
L. Interchangeability and Intermixability of Parts
Refer to Paragraph 2.C., Parts Necessary for Each Airplane, for interchangeability and intermixability
information.
M. Software Accomplishment Summary
Not affected.
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### Page 23

2.    MATERIAL INFORMATION
A. Material - Price and Availability
Boeing can supply the kits/parts shown in Paragraph 2.C., Parts Necessary for Each Airplane. Operators
are encouraged to share schedule requirements with Boeing for incorporation of the service bulletin.
The kits/parts are subject to the terms and conditions of the Boeing standard purchase order
acknowledgment. Prices are in United States Dollars. Terms: Net 30 days.
Reference this service bulletin and submit your purchase order by one of these methods:
1. Order on-line via ATA Spec 2000 or The Boeing PART Page
2. Fax to (206) 662-7145
Group 1, Configuration 1:
REFER TO THE BOEING PART PAGE ON MYBOEINGFLEET.COM OR CONTACT FIRST RESPONDER
AT FR@BOEING.COM FOR THE LATEST REORDER LEAD TIME (ROLT) AND PRICE INFORMATION
Unit Price as of
the Revision 1
date of this Ser-
vice Bulletin (US
Dollars)
ROLT as of the
Revision 1 date of
this Service Bul-
letin (Calendar
Days)
QTYDateNameKit/Part Num-
ber
$5,610.00901November 26,
2014
TOP KIT, RETROFIT -
BMS 8-39 FOAM IN
FLIGHT DECK OVER-
HEAD - REPLACE-
MENT
005W0025-1
25February 17, 2015
24March 17, 2015
25April 14, 2015
$0.30---NUT, SELF-LOCKINGBACN11AG4
(a)
(a) This part is readily available from Boeing spares.
Group 1, Configuration 2:
REFER TO THE BOEING PART PAGE ON MYBOEINGFLEET.COM OR CONTACT FIRST RESPONDER
AT FR@BOEING.COM FOR THE LATEST REORDER LEAD TIME (ROLT) AND PRICE INFORMATION
Unit Price as of
the Revision 1
date of this Ser-
vice Bulletin (US
Dollars)
ROLT as of the
Revision 1 date of
this Service Bul-
letin (Calendar
Days)
QTYDateNameKit/Part Num-
ber
$0.30---NUT, SELF-LOCKINGBACN11AG4
(a)
(a) This part is readily available from Boeing spares.
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Operators are encouraged to complete the survey provided in APPENDIX A of this service bulletin to
help Boeing predict the quantity and timing of the Boeing Supplied Kits/Parts.
B. Industry Support Information
Boeing warranty remedies are not available for the configuration changes given in this service bulletin.
C. Parts Necessary for Each Airplane
1. Kits/Parts
To get the kits/parts shown below, refer to Paragraph 2.A., Material - Price and Availability.
NOTE: One top kit and the items shown in Paragraph 2.C.2., Parts and Materials Supplied by
the Operator, are necessary for each airplane. The Top Kit is divided into Figure kits for
each installation figure shown in the table below.
Group 1, Configuration 1:
Figure Kit
2Top Kit
1005W0025-1
Group 1, Configuration 1:
KIT 005W0025-1
Notes
Existing Part
NumberName
Figure
New Part Number
2
Qty
(a)(b)233W3307-1INSULATION1233W3307-27
(a)(b)233W3307-2INSULATION1233W3307-28
(a)(b)233W3307-11INSULATION1233W3307-29
(a)(b)233W3307-8INSULATION1233W3307-30
(a)(b)233W3307-4INSULATION1233W3307-31
(a)(b)233W3307-4INSULATION1233W3307-32
(a)(b)233W3307-6INSULATION1233W3307-33
(a)(b)233W3307-6INSULATION1233W3307-34
(a)(b)233W3307-3INSULATION1233W3307-35
(a)(b)233W3307-3INSULATION1233W3307-36
(a)(b)233W3307-5INSULATION1233W3307-37
(a)(b)233W3307-5INSULATION1233W3307-38
(a)(b)233W3307-7INSULATION1233W3307-39
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Group 1, Configuration 1:
KIT 005W0025-1
Notes
Existing Part
NumberName
Figure
New Part Number
2
Qty
(a)(b)233W3307-7INSULATION1233W3307-40
(a)(b)233W3307-9INSULATION1233W3307-41
(a) Discard the existing part.
(b) You cannot use the existing part to replace the new or changed part.
Parts
NotesExisting Part
Number
NameQTYNew Part Number
(a)(b)MS21042L4NUT, SELF-LOCKING2BACN11AG4
(a) Discard the existing part.
(b) It is necessary to replace the self-locking nuts in accordance with FIGURE
4 and FIGURE 5.
2. Parts and Materials Supplied by the Operator
The following parts or materials are necessary to do the change in this service bulletin. Parts and
materials in the manuals given in Paragraph 1.J., References, can also be necessary. Examine
operator part and material supply to make sure all necessary parts and materials are available.
NotesNameQTYPart Number / Specification
(a)Tape1 RollBMS 5-157, Type I, Class 1, Grade A, Form 1,
Composition MPVF
(a)(b)Polyvinylidene Fluoride
Foam Insulation
-BMS 8-371, Type 1A, Class 1, Grade 2
(a) Refer to the Qualified Products List at the end of the Boeing Material Specification (BMS) for
supplier data.
(b) Quantity as necessary.
3. Parts Modified and Reidentified
The parts shown below are changed as shown in this service bulletin. The quantity (QTY) is the
number of parts changed on each airplane.
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Group 1, Configuration 1:
NotesNew Part NumberNameQTYExisting Part Number
(a)(b)-OVERHEAD ASSY1233W3311-1, -2, -3, -4, -14,
-16 or -17
(a) Make the change in accordance with this service bulletin.
(b) There is no equivalent Boeing part number for the changed part.
Group 1, Configuration 2:
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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3.    ACCOMPLISHMENT INSTRUCTIONS
A. GENERAL INFORMATION
CAUTION: KEEP THE WORK AREA, WIRES AND ELECTRICAL BUNDLES CLEAN OF METAL
PARTICLES OR CONTAMINATION WHEN YOU USE TOOLS. UNWANTED MATERIAL,
METAL PARTICLES OR CONTAMINATION CAUGHT IN WIRE BUNDLES CAN CAUSE
DAMAGE TO THE BUNDLES. DAMAGED WIRE BUNDLES CAN CAUSE SPARKS OR
OTHER ELECTRICAL DAMAGE.
NOTE: 1. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for
definition of the acronyms.
2. Obey all of the warnings and cautions given in the specified manual sections.
3. Unless shown differently, these dimensions and tolerances are used:
– Linear dimensions are in inches
– Tolerance on linear dimensions, other than rivet and bolt edge margins, is plus
or minus 0.03 inch
– Tolerance on rivet and bolt edge margin is plus or minus 0.05 inch
– Angular tolerance is plus or minus 2 degrees
– Hole dimensions for standard solid rivets and fasteners are in Structural Repair
Manual (SRM) Chapter 51
– Torque Values:
— Values for structural fasteners are given in 777 Structural Repair Manual,
Chapter 51.
— Values for airframe maintenance tasks are included in Chapter 20 of 777
Aircraft Maintenance Manual (AMM).
— Values for electrical maintenance tasks are included in Chapter 20 of
Standard Wiring Practices Manual (SWPM).
4. Use the approved fastener, process and material substitutions in accordance with
SRM Chapter 51.
5. 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.
6. 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.
7. A General Visual Inspection 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.
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8. 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.
9. Refer to APPENDIX B and APPENDIX C for logic diagram(s). Logic diagrams are
provided as an aid only. Information contained in Paragraph 1.E., Compliance is the
primary source for compliance times. Information in Paragraph 3.B., Work Instructions
is the primary source for tasks required for compliance.
10. 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.
11. Where the work instructions include installation of a kept part, a new or serviceable
part with the same part number can be installed as an alternative to the kept part.
12. Use of colors in Figures is based on guidance from the ATA e-Business Program
(ATA) iSpec 2200.
13. The compliance times for the actions in Paragraph 3.B., WORK INSTRUCTIONS
are in Paragraph 1.E., Compliance.
14. Some steps in the Work Instructions are labeled as Required for Compliance (RC).
If this service bulletin is mandated by an Airworthiness Directive (AD), then the steps
labeled as "RC", including sub-steps under an RC step and any figures identified in
an RC step, must be done to comply with the AD. If a step or sub-step is labeled
"RC Exempt" then the RC requirement is removed from that step or sub-step. An
Alternative Method of Compliance (AMOC) is required for any deviations to RC steps,
including sub-steps and identified figures. Steps not labeled as RC may be deviated
from using accepted methods in accordance with the operator's maintenance or
inspection program without obtaining approval of an AMOC. This is provided that
the RC steps, including sub-steps and identified figures, can still be done as specified,
and the airplane can be put back in an airworthy condition.
B. WORK INSTRUCTIONS
Group 1, Configuration 1:
OVERHEAD PANEL SUPPORT STRUCTURE BMS 8-39 URETHANE FOAM INSULATION
INSPECTION AND REPLACEMENT
1. Remove electrical power from the airplane. Refer to 777 AMM 24-22-00 as an acceptable procedure.
2. Get access to the flight compartment.
3. Remove the left and right overhead lining. Refer to 777 AMM 25-15-06 as an accepted procedure.
4. Remove modules from the overhead panel to get access to the overhead panel support structure
in accordance with FIGURE 1.
5. Remove the overhead panel support structure in accordance with FIGURE 4.
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6. RC - Do PART 1: OVERHEAD PANEL SUPPORT STRUCTURE BMS 8-39 URETHANE FOAM
INSULATION REPLACEMENT
7. RC - Do PART 2: GENERAL VISUAL INSPECTION OF THE DRIPSHIELD
a. CONDITION 1: BMS 8-39 URETHANE FOAM INSULATION IS NOT FOUND ON THE
DRIPSHIELD
(1) No further action required.
b. CONDITION 2: BMS 8-39 URETHANE FOAM INSULATION IS FOUND ON THE DRIPSHIELD
(1) Do PART 3: DRIPSHIELD BMS 8-39 URETHANE FOAM INSULATION REPLACEMENT
8. Install the overhead panel support structure in accordance with FIGURE 5.
9. Close access in accordance with FIGURE 3.
10. Install the left and right overhead lining. Refer to 777 AMM 25-15-06 as an accepted procedure.
11. Supply electrical power to the airplane. Refer to 777 AMM 24-22-00 as an acceptable procedure.
12. Do the tests in accordance with PART 4: OPERATIONAL TESTS OF THE OVERHEAD PANEL
MODULES
13. Put the airplane back to a serviceable condition.
Group 1, Configuration 2:
GENERAL VISUAL INSPECTION OF THE DRIPSHIELD, ABOVE THE OVERHEAD PANEL SUPPORT
STRUCTURE, FOR BMS 8-39 URETHANE FOAM INSULATION
1. Remove electrical power from the airplane. Refer to 777 AMM 24-22-00 as an acceptable procedure.
2. Get access to the flight compartment.
3. Remove modules from the overhead panel to get access to see the dripshield in accordance with
FIGURE 6.
4. RC - Do PART 2: GENERAL VISUAL INSPECTION OF THE DRIPSHIELD
a. CONDITION 1: BMS 8-39 URETHANE FOAM INSULATION IS NOT FOUND ON THE
DRIPSHIELD
(1) No further action required.
(2) RC Exempt - Close access in accordance with FIGURE 9.
b. CONDITION 2: BMS 8-39 URETHANE FOAM INSULATION IS FOUND ON THE DRIPSHIELD
(1) RC Exempt - Get more access to the dripshield in accordance with FIGURE 1.
(2) RC Exempt - Remove the overhead panel support structure in accordance with FIGURE
4.
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### Page 30

(3) Do PART 3: DRIPSHIELD BMS 8-39 URETHANE FOAM INSULATION REPLACEMENT
(4) RC Exempt - Install the overhead panel support structure in accordance with FIGURE 5.
(5) RC Exempt - Close access in accordance with FIGURE 3.
5. Supply electrical power to the airplane. Refer to 777 AMM 24-22-00 as an acceptable procedure.
6. Do the tests in accordance with PART 4: OPERATIONAL TESTS OF THE OVERHEAD PANEL
MODULES
7. Put the airplane back to a serviceable condition.
PART 1: OVERHEAD PANEL SUPPORT STRUCTURE BMS 8-39 URETHANE FOAM INSULATION
REPLACEMENT
1. Replace BMS 8-39 urethane foam insulation on the overhead panel support structure in accordance
with FIGURE 2.
PART 2: GENERAL VISUAL INSPECTION OF THE DRIPSHIELD
1. Do a General Visual Inspection of the dripshield, above the overhead panel support structure, for
BMS 8-39 urethane foam insulation in accordance with FIGURE 7.
PART 3: DRIPSHIELD BMS 8-39 URETHANE FOAM INSULATION REPLACEMENT
1. Replace all BMS 8-39 urethane foam insulation found on the dripshield in accordance with FIGURE
8.
PART 4: OPERATIONAL TESTS OF THE OVERHEAD PANEL MODULES
1. Do a related test of the remaining modules that were removed and installed in the overhead panel
support structure during the accomplishment of this work. If a test fails, do the corrective action
and repeat the test until the test is passed.
a. Flight Control Hydraulic Valve Power Module:
(1) Do the Hydraulic Shutoff Valves Test. Refer to 777 AMM 27-02-32 as an accepted
procedure.
b. Auxiliary Power Unit (APU) Maintenance / Electronic Engine Control (EEC) Maintenance
Module:
(1) Do the APU Bite Test. Refer to 777 AMM 49-11-00 as an accepted procedures.
(2) For airplanes with PW 4000 series engines, do the Electronic Engine Control (EEC)
System Static Test. Refer to 777 AMM 73-21-00 as an accepted procedure.
(3) For airplanes with Trent 800 or GE90 series engines, do the Electronic Engine Control
(EEC) NORM/ALTN Mode Lights Inoperative test. Refer to 777 AMM 73-00-00 as an
accepted procedure.
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### Page 31

c. Ground Test Module:
(1) Do the Lower Cargo Compartment Smoke Detection MAT Test. Refer to 777 AMM
26-16-00 as an accepted procedure.
d. Left and Right Wiper Modules:
(1) Do the Windshield Wiper System - Operation Test. Refer to 777 AMM 30-42-00 as an
accepted procedure.
e. Pass Signs Module:
(1) Do the Cockpit Voice Recorder Microphone Installation Test. Refer to 777 AMM 23-71-04
as an accepted procedure.
(2) Do the Flight Compartment Illumination - Operational Test. Refer to 777 AMM 33-11-00
as an accepted procedure.
(3) Do the Landing, Runway Turnoff and Taxi Lights - Operational Test. Refer to 777 AMM
33-42-00 as an accepted procedure.
f. Anti-Ice Module:
(1) Do the Wing Anti-Ice - System Test. Refer to 777 AMM 30-11-00 as an accepted
procedure.
(2) Do the Engine Anti-Ice - System Test. Refer to 777 AMM 30-21-00 as an accepted
procedure.
g. APU Fire Switch Panel:
(1) Do the APU Fire Switch Installation Test. Refer to 777 AMM 26-22-03 as an accepted
procedure.
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### Page 32 (OCR)

BOEING SERVICE BULLETIN 777-25-0621
FLIGHT COMPARTMENT
(3
→
- 12
14)
OVERHEAD PANEL
(TYPICAL)  2376213
FIGURE 1: FLIGHT COMPARTMENT - OVERHEAD PANEL - OPEN ACCESS
(SHEET 1 OF 5)
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### Page 33

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 airplane.
More DataQtyIdentificationNameTaskStep
Disengage the quar-
ter-turn fasteners to
remove the blank
panels.
2-BLANK PANELRemove / Keep1
Refer to 777 AMM
30-41-12 as an ac-
cepted procedure.
1-WINDOW HEAT
BACKUP MODULE
Remove / Keep2
Disengage the quar-
ter-turn fasteners to
pull out the module,
then disconnect the
electrical connectors
at the back of the
module.
1-FLT CONTROL HYD
VALVE POWER MOD-
ULE
Remove / Keep
Disengage the quar-
ter-turn fasteners to
remove the blank
panels.
1-BLANK PANELRemove / Keep
Disengage the quar-
ter-turn fasteners to
pull out the module,
then disconnect the
electrical connectors
at the back of the
module.
1-APU MAINT / EEC
MAINT MODULE
Remove / Keep3
Disengage the quar-
ter-turn fasteners to
pull out the module,
then disconnect the
electrical connectors
at the back of the
module.
1-GND TEST MODULERemove / Keep
Refer to 777 AMM
21-44-09 as an ac-
cepted procedure.
1-CARGO TEMP SE-
LECT MODULE
Remove / Keep
Refer to 777 AMM
23-71-02 as an ac-
cepted procedure.
1-COCKPIT VOICE
RECORDER MODULE
Remove / Keep
FIGURE 1: FLIGHT COMPARTMENT - OVERHEAD PANEL - OPEN ACCESS
(SHEET 2 OF 5)
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### Page 34

More DataQtyIdentificationNameTaskStep
Refer to 777 AMM
23-92-02 as an ac-
cepted procedure.
2-OVERHEAD PANEL
CARD FILE
Remove / Keep4
-2-P11 CIRCUIT BREAK-
ER PANEL
Open5
Disconnect electrical
connectors from dis-
connect panels
AF0201 and
AF0202.
--ELECTRICAL CON-
NECTORS
Disconnect
Disconnect wiring
from terminal
block(s). Identify the
location of wire to
help put them back
in the same location
during installation.
--WIRINGDisconnect
Refer to 777 AMM
23-24-03 as an ac-
cepted procedure.
(a)
1-ELT MODULERemove / Keep6
Disengage the quar-
ter-turn fasteners to
remove the blank
panels. (b)
1-BLANK PANELRemove / Keep7
Refer to 777 AMM
30-41-02 as an ac-
cepted procedure.
1-WINDOW HEAT/EMER
LIGHTS MODULE
Remove / Keep8
Refer to 777 AMM
27-02-03 as an ac-
cepted procedure.
1-PRIMARY FLIGHT
COMPUTER/ADIRU
MODULE
Remove / Keep9
Refer to 777 AMM
29-11-80 as an ac-
cepted procedure.
1-HYDRAULIC/RAM AIR
TURBINE MODULE
Remove / Keep10
Refer to 777 AMM
24-22-01 as an ac-
cepted procedure.
1-ELECTRICAL SYST
CONTROL PANEL
Remove / Keep11
FIGURE 1: FLIGHT COMPARTMENT - OVERHEAD PANEL - OPEN ACCESS
(SHEET 3 OF 5)
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### Page 35

More DataQtyIdentificationNameTaskStep
Disengage the quar-
ter-turn fasteners to
pull out the module,
then disconnect the
electrical connectors
at the back of the
module.
1-L WIPER MODULERemove / Keep12
Disengage the quar-
ter-turn fasteners to
pull out the module,
then disconnect the
electrical connectors
at the back of the
module.
1-R WIPER MODULERemove / Keep
Disengage the quar-
ter-turn fasteners to
pull out the module,
then disconnect the
electrical connectors
at the back of the
module.
1-PASS SIGNS MODULERemove / Keep13
Disengage the quar-
ter-turn fasteners to
pull out the module,
then disconnect the
electrical connectors
at the back of the
module.
1-ANTI-ICE MODULERemove / Keep14
Refer to 777 AMM
36-11-10 as an ac-
cepted procedure.
1-BLEED AIR/PRESSUR-
IZATION MODULE
Remove / Keep15
Refer to 777 AMM
28-22-17 as an ac-
cepted procedure.
1-FUEL SYST MODULERemove / Keep16
Disengage the quar-
ter-turn fasteners to
remove the blank
panels.
1-BLANK PANELRemove / Keep17
Refer to 777 AMM
21-60-01 as an ac-
cepted procedure.
1-A/C MODULERemove / Keep
FIGURE 1: FLIGHT COMPARTMENT - OVERHEAD PANEL - OPEN ACCESS
(SHEET 4 OF 5)
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### Page 36

More DataQtyIdentificationNameTaskStep
Refer to 777 AMM
26-22-04 as an ac-
cepted procedure.
1-CARGO FIRE/ENGINE
CONTROL MODULE
Remove / Keep18
Disengage the quar-
ter-turn fasteners to
pull out the module,
then disconnect the
electrical connectors
at the back of the
panel.
1-APU FIRE SWITCH
PANEL
Remove / Keep
(a) Some airplanes have a blank panel on the upper half and an Emergency Locator Transmitter (ELT)
Module on the lower half of this location. Remove and keep.
(b) Some airplanes have a blank panel on the upper half and a Broadband System Module on the lower half
of this location. Remove and keep the two.
FIGURE 1: FLIGHT COMPARTMENT - OVERHEAD PANEL - OPEN ACCESS
(SHEET 5 OF 5)
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### Page 37

This Figure applies only to: Group 1, Configuration 1.
FIGURE 2: FLIGHT COMPARTMENT - OVERHEAD PANEL SUPPORT STRUCTURE, BMS 8-39 URETHANE
FOAM INSULATION REPLACEMENT
(SHEET 1 OF 3)
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### Page 38 (OCR)

BOEING SERVICE BULLETIN 777-25-0621
Br
(10) 26
3 11 24
А-А  10 26
B-B
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 airplane.
Step  Task  Name  Identification  Qty  More Data
Remove  INSULATION  233W3307-5  2
2  Remove  INSULATION  233W3307-9  1
З  Remove  INSULATION  233W3307-8  1
4  Remove  INSULATION  233W3307-7  2
5  Remove  INSULATION  233W3307-4  2
6  Remove  INSULATION  233W3307-3  2
Remove  INSULATION  233W3307-6  2
8  Remove  INSULATION  233W3307-1  1
Remove  INSULATION  233W3307-2  1
10  Remove  INSULATION  233W3307-11  1
11  Clean  PANEL SUPPORT  (a)
STRUCTURE
12  Install (New)  INSULATION  233W3307-37  1  (b)
| FIGURE 2: FLIGHT COMPARTMENT - OVERHEAD PANEL SUPPORT STRUCTURE, BMS 8-39 URETHANE
FOAM INSULATION REPLACEMENT
(SHEET 2 OF 3)
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### Page 39

More DataQtyIdentificationNameTaskStep
(b)1233W3307-38INSULATIONInstall (New)13
(b)1233W3307-41INSULATIONInstall (New)14
(b)1233W3307-30INSULATIONInstall (New)15
(b)1233W3307-39INSULATIONInstall (New)16
(b)1233W3307-40INSULATIONInstall (New)17
(b)1233W3307-31INSULATIONInstall (New)18
(b)1233W3307-32INSULATIONInstall (New)19
(b)1233W3307-35INSULATIONInstall (New)20
(b)1233W3307-36INSULATIONInstall (New)21
(b)1233W3307-33INSULATIONInstall (New)22
(b)1233W3307-34INSULATIONInstall (New)23
(b)1233W3307-27INSULATIONInstall (New)24
(b)1233W3307-28INSULATIONInstall (New)25
(b)1233W3307-29INSULATIONInstall (New)26
(c)-777-25-0621 R01SERVICE BULLETIN
NUMBER
Apply27
(a) Clean to prepare the surfaces for bonding BMS 8-371 foam insulation. Remove debris after cleaning and
do a general clean again. Refer to SOPM 20-30-03 as an accepted procedure.
(b) To bond foam insulation on the structure, make sure the side of the foam insulation that has the adhesive
faces the structure. To bond foam insulation in position, it is acceptable to use BMS 5-157, Type I, Class
1, Grade A, Form 1, Composition MPVF tape. Align holes in the foam insulation and structure. Cut foam
insulation to let it fit around ducts and brackets.
(c) Identify the overhead panel support structure with this service bulletin number to show that it is changed.
Refer to SOPM 20-50-10 as an accepted procedure.
FIGURE 2: FLIGHT COMPARTMENT - OVERHEAD PANEL SUPPORT STRUCTURE, BMS 8-39 URETHANE
FOAM INSULATION REPLACEMENT
(SHEET 3 OF 3)
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### Page 40 (OCR)

BOEING SERVICE BULLETIN 777-25-0621
FLIGHT COMPARTMENT
(3)
(12
14)
OVERHEAD PANEL
(TYPICAL)
2376554
FIGURE 3: FLIGHT COMPARTMENT - OVERHEAD PANEL - CLOSE ACCESS
(SHEET 1 OF 5)
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### Page 41

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 airplane.
More DataQtyIdentificationNameTaskStep
With the blank panel
in its position, en-
gage the quarter-
turn fasteners at all
fastener locations.
2-BLANK PANELInstall (Kept)1
Refer to 777 AMM
30-41-12 as an ac-
cepted procedure.
1-WINDOW HEAT
BACKUP MODULE
Install (Kept)2
Connect the electri-
cal connectors, then
with the module in
its position, engage
the quarter-turn fas-
teners at all fastener
locations.
1-FLT CONTROL HYD
VALVE POWER MOD-
ULE
Install (Kept)
With the blank panel
in its position, en-
gage the quarter-
turn fasteners at all
fastener locations.
1-BLANK PANELInstall (Kept)
Connect the electri-
cal connectors, then
with the module in
its position, engage
the quarter-turn fas-
teners at all fastener
locations.
1-APU MAINT / EEC
MAINT MODULE
Install (Kept)3
Connect the electri-
cal connectors, then
with the module in
its position, engage
the quarter-turn fas-
teners at all fastener
locations.
1-GND TEST MODULEInstall (Kept)
Refer to 777 AMM
21-44-09 as an ac-
cepted procedure.
1-CARGO TEMP SE-
LECT MODULE
Install (Kept)
Refer to 777 AMM
23-71-02 as an ac-
cepted procedure.
1-COCKPIT VOICE
RECORDER MODULE
Install (Kept)
FIGURE 3: FLIGHT COMPARTMENT - OVERHEAD PANEL - CLOSE ACCESS
(SHEET 2 OF 5)
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### Page 42

More DataQtyIdentificationNameTaskStep
Refer to 777 AMM
23-92-02 as an ac-
cepted procedure.
2-OVERHEAD PANEL
CARD FILE
Install (Kept)4
Connect wiring back
in to terminal
block(s), in the same
locations they were
removed from.
--WIRINGConnect5
Connect electrical
connector back on
to disconnect panels
AF0201 and
AF0202.
--ELECTRICAL CON-
NECTORS
Connect
-2-P11 CIRCUIT BREAK-
ER PANEL
Close
Refer to 777 AMM
23-24-03 as an ac-
cepted procedure.
(a)
1-ELT MODULEInstall (Kept)6
With the blank panel
in its position, en-
gage the quarter-
turn fasteners at all
fastener locations.
(b)
1-BLANK PANELInstall (Kept)7
Refer to 777 AMM
30-41-02 as an ac-
cepted procedure.
1-WINDOW HEAT/EMER
LIGHTS MODULE
Install (Kept)8
Refer to 777 AMM
27-02-03 as an ac-
cepted procedure.
1-PRIMARY FLIGHT
COMPUTER/ADIRU
MODULE
Install (Kept)9
Refer to 777 AMM
29-11-80 as an ac-
cepted procedure.
1-HYDRAULIC/RAM AIR
TURBINE MODULE
Install (Kept)10
Refer to 777 AMM
24-22-01 as an ac-
cepted procedure.
1-ELECTRICAL SYST
CONTROL PANEL
Install (Kept)11
FIGURE 3: FLIGHT COMPARTMENT - OVERHEAD PANEL - CLOSE ACCESS
(SHEET 3 OF 5)
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### Page 43

More DataQtyIdentificationNameTaskStep
Connect the electri-
cal connectors, then
with the module in
its position, engage
the quarter-turn fas-
teners at all fastener
locations.
1-L WIPER MODULEInstall (Kept)12
Connect the electri-
cal connectors, then
with the module in
its position, engage
the quarter-turn fas-
teners at all fastener
locations.
1-R WIPER MODULEInstall (Kept)
Connect the electri-
cal connectors, then
with the module in
its position, engage
the quarter-turn fas-
teners at all fastener
locations.
1-PASS SIGNS MODULEInstall (Kept)13
Connect the electri-
cal connectors, then
with the module in
its position, engage
the quarter-turn fas-
teners at all fastener
locations.
1-ANTI-ICE MODULEInstall (Kept)14
Refer to 777 AMM
36-11-10 as an ac-
cepted procedure.
1-BLEED AIR/PRESSUR-
IZATION MODULE
Install (Kept)15
Refer to 777 AMM
28-22-17 as an ac-
cepted procedure.
1-FUEL SYST MODULEInstall (Kept)16
With the blank panel
in its position, en-
gage the quarter-
turn fasteners at all
fastener locations.
1-BLANK PANELInstall (Kept)17
Refer to 777 AMM
21-60-01 as an ac-
cepted procedure.
1-A/C MODULEInstall (Kept)
FIGURE 3: FLIGHT COMPARTMENT - OVERHEAD PANEL - CLOSE ACCESS
(SHEET 4 OF 5)
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### Page 44

More DataQtyIdentificationNameTaskStep
Refer to 777 AMM
26-22-04 as an ac-
cepted procedure.
1-CARGO FIRE/ENGINE
CONTROL MODULE
Install (Kept)18
Connect the electri-
cal connectors, then
with the panel in its
position, engage the
quarter-turn fasten-
ers at all fastener lo-
cations.
1-APU FIRE SWITCH
PANEL
Install (Kept)
(a) If a blank panel was also removed at this location, install it by positioning the blank panel in its location
then engaging the quarter-turn fasteners at all fastener locations.
(b) If a Broadband System Module was also removed at this location, connect the electrical connectors, then
with the module in its position, engage the quarter-turn fasteners at all fastener locations.
FIGURE 3: FLIGHT COMPARTMENT - OVERHEAD PANEL - CLOSE ACCESS
(SHEET 5 OF 5)
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### Page 45 (OCR)

BOEING SERVICE BULLETIN 777-25-0621
STA
228.44
STA
166.53
2489045
FIGURE 4: FLIGHT COMPARTMENT - OVERHEAD PANEL SUPPORT STRUCTURE - REMOVAL
(SHEET 1 OF 3)
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### Page 46 (OCR)

BOEING SERVICE BULLETIN 777-25-0621
• 4 LOCATIONS
2) 4 LOCATIONS
FWD
TYPICAL  TYPICAL
(2 LOCATIONS)  (2 LOCATIONS)
LBL
1.39
RBL  (3) 4 LOCATIONS
1.63
(5) 4 LOCATIONS
TYPICAL
(2 LOCATIONS)
A-A  2489053
FIGURE 4: FLIGHT COMPARTMENT - OVERHEAD PANEL SUPPORT STRUCTURE - REMOVAL
(SHEET 2 OF 3)
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PROPRIETARY - Copyright © Unpublished
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### Page 47

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for each airplane.
More DataQtyIdentificationNameTaskStep
2BACN11AG4NUT, SELF-LOCKINGRemove1
2NAS1149D0416HWASHERRemove / Keep
2BACJ40K7A7A22BONDING JUMPERDisconnect
8BACB30LT4-9BOLTRemove / Keep2
8NAS1149F0432PWASHERRemove / Keep
8BACB30LT3-9BOLTRemove / Keep3
8NAS1149F0332PWASHERRemove / Keep
8BACB30LT4-9BOLTRemove / Keep4
8NAS1149F0432PWASHERRemove / Keep
4BACB30LT3-9BOLTRemove / Keep5
4NAS1149F0332PWASHERRemove / Keep
Disconnect ducts as
necessary.
--DUCT ASSEMBLIESDisconnect6
1233W3311-( )OVERHEAD ASSYRemove / Keep
FIGURE 4: FLIGHT COMPARTMENT - OVERHEAD PANEL SUPPORT STRUCTURE - REMOVAL
(SHEET 3 OF 3)
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### Page 48 (OCR)

BOEING SERVICE BULLETIN 777-25-0621
STA
228.44
FWD
STA
166.53
2489051
FIGURE 5: FLIGHT COMPARTMENT - OVERHEAD PANEL SUPPORT STRUCTURE - INSTALLATION
(SHEET 1 OF 3)
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### Page 49 (OCR)

BOEING SERVICE BULLETIN 777-25-0621
(3) 4 LOCATIONS
(5) 4 LOCATIONS
FWD
TYPICAL  TYPICAL
(2 LOCATIONS)  (2 LOCATIONS)
LBL
1.39
RBL  (4) 4 LOCATIONS
1.63
(3) 4 LOCATIONS
FWD
TYPICAL
(2 LOCATIONS)
A-A  2499127
FIGURE 5: FLIGHT COMPARTMENT - OVERHEAD PANEL SUPPORT STRUCTURE - INSTALLATION
(SHEET 2 OF 3)
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### Page 50

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for each airplane.
More DataQtyIdentificationNameTaskStep
1233W3311-( )OVERHEAD ASSYInstall (Kept)1
Connect ducts as
necessary.
--DUCT ASSEMBLIESConnect
4NAS1149F0332PWASHERInstall (Kept)2
4BACB30LT3-9BOLTInstall (Kept)
8NAS1149F0432PWASHERInstall (Kept)3
8BACB30LT4-9BOLTInstall (Kept)
8NAS1149F0332PWASHERInstall (Kept)4
8BACB30LT3-9BOLTInstall (Kept)
8NAS1149F0432PWASHERInstall (Kept)5
8BACB30LT4-9BOLTInstall (Kept)
(a)2BACJ40K7A7A22BONDING JUMPERConnect6
2NAS1149D0416HWASHERInstall (Kept)
Position bonding
jumper terminals as
shown, before they
are tightened, to
make sure they do
not interfere with the
overhead support
structure and hard-
ware.
2BACN11AG4NUT, SELF-LOCKINGInstall (New)
(a) Make sure the electrical resistance is not more than 1.0 milliohms. Refer to SOPM 20-11-03 as an accepted
procedure.
FIGURE 5: FLIGHT COMPARTMENT - OVERHEAD PANEL SUPPORT STRUCTURE - INSTALLATION
(SHEET 3 OF 3)
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: December 10, 2014
777-25-0621Revision 1 August 04, 2017
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BOEING SERVICE BULLETIN 777-25-0621

### Page 51 (OCR)

BOEING SERVICE BULLETIN 777-25-0621
This Figure applies only to: Group 1, Configuration 2.
FLIGHT COMPARTMENT
OVERHEAD PANEL
(TYPICAL)  2570107
FIGURE 6: FLIGHT COMPARTMENT - OVERHEAD PANEL - OPEN ACCESS
(SHEET 1 OF 3)
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Work - See page 1 for details.  51 of 65

### Page 52

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for each airplane.
More DataQtyIdentificationNameTaskStep
Refer to 777 AMM
30-41-12 as an ac-
cepted procedure.
1-WINDOW HEAT
BACKUP MODULE
Remove / Keep1
Disengage the quar-
ter-turn fasteners to
pull out the module,
then disconnect the
electrical connectors
at the back of the
module.
1-FLT CONTROL HYD
VALVE POWER MOD-
ULE
Remove / Keep
Disengage the quar-
ter-turn fasteners to
remove the blank
panel.
1-BLANK PANELRemove / Keep
Disengage the quar-
ter-turn fasteners to
pull out the module,
then disconnect the
electrical connectors
at the back of the
module.
1-APU MAINT / EEC
MAINT MODULE
Remove / Keep2
Disengage the quar-
ter-turn fasteners to
pull out the module,
then disconnect the
electrical connectors
at the back of the
module.
1-GND TEST MODULERemove / Keep
Refer to 777 AMM
21-44-09 as an ac-
cepted procedure.
1-CARGO TEMP SE-
LECT MODULE
Remove / Keep
Refer to 777 AMM
23-71-02 as an ac-
cepted procedure.
1-COCKPIT VOICE
RECORDER MODULE
Remove / Keep
-2-P11 CIRCUIT BREAK-
ER PANEL
Open3
Disengage the quar-
ter-turn fasteners to
remove the blank
panel. (a)
1-BLANK PANELRemove / Keep4
FIGURE 6: FLIGHT COMPARTMENT - OVERHEAD PANEL - OPEN ACCESS
(SHEET 2 OF 3)
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: December 10, 2014
777-25-0621Revision 1 August 04, 2017
52 of 65
BOEING SERVICE BULLETIN 777-25-0621

### Page 53

More DataQtyIdentificationNameTaskStep
Disengage the quar-
ter-turn fasteners to
remove the blank
panel.
1-BLANK PANELRemove / Keep5
Disengage the quar-
ter-turn fasteners to
pull out the module,
then disconnect the
electrical connectors
at the back of the
module.
1-L WIPER MODULERemove / Keep6
Disengage the quar-
ter-turn fasteners to
pull out the module,
then disconnect the
electrical connectors
at the back of the
module.
1-R WIPER MODULERemove / Keep7
(a) Some airplanes have a blank panel on the upper half and a Broadband System Module on the lower half
of this location. Remove and keep the two.
FIGURE 6: FLIGHT COMPARTMENT - OVERHEAD PANEL - OPEN ACCESS
(SHEET 3 OF 3)
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: December 10, 2014
777-25-0621Revision 1 August 04, 2017
53 of 65
BOEING SERVICE BULLETIN 777-25-0621

### Page 54 (OCR)

BOEING SERVICE BULLETIN 777-25-0621
FWD
DRIPSHIELD  2570344
TFIGURE7: FLIGHT COMPARTMENT - DRIPSHIELD, BMS 8-39 URETHANE FOAM INSULATION - GENERAL
VISUAL INSPECTION
(SHEET 1 OF 2)
Original Issue: December 10, 2014
Revision 1 August 04, 2017  PROPRIETARY - Copyright © Unpublished  Export Controlled ECCN: 9E991 - BOEING  777-25-0621
Work - See page 1 for details.  54 of 65

### Page 55

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for each airplane.
More DataQtyIdentificationNameTaskStep
(a)(b)(c)--DRIPSHIELDInspect1
(a) Do a General Visual Inspection to see if BMS 8-39 urethane foam insulation is installed on the dripshield
at the overhead support structure locations identified.
(b) Refer to APPENDIX D for a typical installation of BMS 8-39 urethane foam insulation.
(c) Degraded urethane foam insulation can be sticky or crumbly to the touch. Black dust is an example of
degraded urethane foam insulation.
FIGURE 7: FLIGHT COMPARTMENT - DRIPSHIELD, BMS 8-39 URETHANE FOAM INSULATION - GENERAL
VISUAL INSPECTION
(SHEET 2 OF 2)
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: December 10, 2014
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BOEING SERVICE BULLETIN 777-25-0621

### Page 56 (OCR)

BOEING SERVICE BULLETIN 777-25-0621
FWD
DRIPSHIELD  2570378
FIGURE 8: FLIGHT COMPARTMENT - DRIPSHIELD, BMS 8-39 URETHANE FOAM INSULATION -
REPLACEMENT
(SHEET 1 OF 2)
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Work - See page 1 for details.  56 of 65

### Page 57

The step numbers shown below agree with the numbers shown in the circle symbols in the figure.
More DataQtyIdentificationNameTaskStep
Remove all urethane
foam insulation
found.
-BMS 8-39URETHANE FOAM IN-
SULATION
Remove1
(a)--DRIPSHIELDClean2
(b)-BMS 8-371, TYPE 1A,
CLASS 1, GRADE 2
POLYVINYLIDENE
FLUORIDE FOAM IN-
SULATION
Install (New)3
(a) Clean to prepare the surfaces for bonding BMS 8-371 polyvinylidene fluoride foam insulation. Remove
debris after cleaning and do a general clean again. Refer to SOPM 20-30-03 as an accepted procedure.
(b) To bond polyvinylidene fluoride foam insulation on the dripshield at each location BMS 8-39 urethane
foam insulation was removed. Make sure the side of the foam insulation that has the adhesive faces the
dripshield. To bond the foam insulation in position, it is acceptable to use BMS 5-157, Type I, Class 1,
Grade A, Form 1, Composition MPVF tape. Cut foam insulation to let it fit around ducts and brackets.
FIGURE 8: FLIGHT COMPARTMENT - DRIPSHIELD, BMS 8-39 URETHANE FOAM INSULATION -
REPLACEMENT
(SHEET 2 OF 2)
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: December 10, 2014
777-25-0621Revision 1 August 04, 2017
57 of 65
BOEING SERVICE BULLETIN 777-25-0621

### Page 58 (OCR)

BOEING SERVICE BULLETIN 777-25-0621
This Figure applies only to: Group 1, Configuration 2.
FLIGHT COMPARTMENT
(5
OVERHEAD PANEL
(TYPICAL)  2570108
FIGURE 9: FLIGHT COMPARTMENT - OVERHEAD PANEL - CLOSE ACCESS
(SHEET 1 OF 3)
Original Issue: December 10, 2014
Revision 1 August 04, 2017  Export Controlled ECCN: 9E991 - BOEING  PROPRIETARY - Copyright © Unpublished  777-25-0621
Work - See page 1 for details.  58 of 65

### Page 59

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for each airplane.
More DataQtyIdentificationNameTaskStep
Refer to 777 AMM
30-41-12 as an ac-
cepted procedure.
1-WINDOW HEAT
BACKUP MODULE
Install (Kept)1
Connect the electri-
cal connectors, then
with the module in
its position, engage
the quarter-turn fas-
teners at all fastener
locations.
1-FLT CONTROL HYD
VALVE POWER MOD-
ULE
Install (Kept)
With the blank panel
in its position, en-
gage the quarter-
turn fasteners at all
fastener locations.
1-BLANK PANELInstall (Kept)
Connect the electri-
cal connectors, then
with the module in
its position, engage
the quarter-turn fas-
teners at all fastener
locations.
1-APU MAINT / EEC
MAINT MODULE
Install (Kept)2
Connect the electri-
cal connectors, then
with the module in
its position, engage
the quarter-turn fas-
teners at all fastener
locations.
1-GND TEST MODULEInstall (Kept)
Refer to 777 AMM
21-44-09 as an ac-
cepted procedure.
1-CARGO TEMP SE-
LECT MODULE
Install (Kept)
Refer to 777 AMM
23-71-02 as an ac-
cepted procedure.
1-COCKPIT VOICE
RECORDER MODULE
Install (Kept)
-2-P11 CIRCUIT BREAK-
ER PANEL
Close3
FIGURE 9: FLIGHT COMPARTMENT - OVERHEAD PANEL - CLOSE ACCESS
(SHEET 2 OF 3)
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: December 10, 2014
777-25-0621Revision 1 August 04, 2017
59 of 65
BOEING SERVICE BULLETIN 777-25-0621

### Page 60

More DataQtyIdentificationNameTaskStep
With the blank panel
in its position, en-
gage the quarter-
turn fasteners at all
fastener locations.
(a)
1-BLANK PANELInstall (Kept)4
With the blank panel
in its position, en-
gage the quarter-
turn fasteners at all
fastener locations.
1-BLANK PANELInstall (Kept)5
Connect the electri-
cal connectors, then
with the module in
its position, engage
the quarter-turn fas-
teners at all fastener
locations.
1-L WIPER MODULEInstall (Kept)6
Connect the electri-
cal connectors, then
with the module in
its position, engage
the quarter-turn fas-
teners at all fastener
locations.
1-R WIPER MODULEInstall (Kept)7
(a) If a Broadband System Module was also removed at this location, connect the electrical connectors, then
with the module in its position, engage the quarter-turn fasteners at all fastener locations.
FIGURE 9: FLIGHT COMPARTMENT - OVERHEAD PANEL - CLOSE ACCESS
(SHEET 3 OF 3)
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: December 10, 2014
777-25-0621Revision 1 August 04, 2017
60 of 65
BOEING SERVICE BULLETIN 777-25-0621

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