# Boeing Alert Service Bulletin 777-53A0075: Revision 1

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- Document: [Boeing Alert Service Bulletin 777-53A0075](https://openairdocs.org/service-documents/boeing/777-53a0075.md)
- Title as filed: U.S. DOT/FAA - SB-777-53A0075-00
- Pages: 232
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### Page 1

Commercial 
Airplanes
777
Service Bulletin
ALERT
Number: 777-53A0075
Original Issue: January 14, 2015
ATA System: 5380
SUBJECT: FUSELAGE - Section 48 - Station 2370 Pivot Bulkhead Forward Outer Chord -
Inspection and Repair
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 © 2015 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Unpublished Work.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.
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3.0

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Table of Contents
Summary ...................................................... 5
1. PLANNING INFORMATION ........................................ 9
A. Effectivity ................................................ 9
1. Airplanes ............................................. 9
2. Spares Affected ........................................ 1 1
B. Concurrent Requirements ...................................... 1 1
C. Reason ................................................ 1 1
D. Description .............................................. 1 1
E. Compliance .............................................. 1 2
F. Approval ............................................... 1 5
G. Manpower .............................................. 1 6
H. Weight and Balance Changes .................................... 1 8
I. Electrical Load Data ......................................... 1 9
J. References .............................................. 1 9
1. Existing Data: ......................................... 1 9
2. Data Supplied with this Service Bulletin: ........................... 1 9
3. Installation Drawings Used in the Preparation of this Service Bulletin: ........... 1 9
K. Publications Affected ........................................ 2 0
L. Interchangeability and Intermixability of Parts ........................... 2 0
M. Software Accomplishment Summary ................................ 2 0
2. MATERIAL INFORMATION ........................................ 2 1
A. Material - Price and Availability ................................... 2 1
B. Industry Support Information .................................... 2 2
C. Parts Necessary for Each Airplane ................................. 2 2
1. Kits/Parts ............................................ 2 2
2. Parts and Materials Supplied by the Operator ........................ 2 7
3. Parts Modified and Reidentified ................................ 2 7
4. Parts Removed and Not Replaced .............................. 2 7
D. Parts Necessary to Change Spares ................................. 2 7
E. Special Tooling - Price and Availability ............................... 2 7
F. Special Tooling Necessary to do this Service Bulletin ....................... 2 7
3. ACCOMPLISHMENT INSTRUCTIONS .................................. 2 9
A. GENERAL INFORMATION ..................................... 2 9
B. WORK INSTRUCTIONS ....................................... 3 1
FIGURE 1: LEFT SIDE - STA 2370 SKIN PANEL REMOVAL ...................... 3 6
FIGURE 2: RIGHT SIDE - STA 2370 SKIN PANEL REMOVAL ..................... 4 0
FIGURE 3: LEFT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD - DET AND HFEC
INSPECTION .......................................... 4 4
FIGURE 4: RIGHT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD - DET AND HFEC
INSPECTION .......................................... 4 8
FIGURE 5: LEFT SIDE - STA 2370 SKIN PANEL INSTALLATION ................... 5 2
FIGURE 6: RIGHT SIDE - STA 2370 SKIN PANEL INSTALLATION ................... 5 7
FIGURE 7: LEFT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD - PART REMOVAL
[Group 1] ............................................ 6 2
FIGURE 8: RIGHT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD - PART REMOVAL
[Group 1] ............................................ 7 2
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FIGURE 9: LEFT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD - PART REMOVAL
[Group 2] ............................................ 8 2
FIGURE 10: RIGHT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD - PART REMOVAL
[Group 2] ............................................ 9 2
FIGURE 11: LEFT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD AND ADJACENT
STRUCTURE - HFEC AND DET INSPECTION ....................... 1 0 2
FIGURE 12: RIGHT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD AND ADJACENT
STRUCTURE - HFEC AND DET INSPECTION ....................... 1 0 7
FIGURE 13: LEFT SIDE - STA 2370 - SPLICE ANGLE - MODIFICATION [Group 1] .......... 1 1 2
FIGURE 14: RIGHT SIDE - STA 2370 - SPLICE ANGLE - MODIFICATION [Group 1] ......... 1 1 5
FIGURE 15: LEFT SIDE - STA 2370 PIVOT BULKHEAD FORWARD CHORD - REPAIR [Group 1] . 118
FIGURE 16: RIGHT SIDE - STA 2370 PIVOT BULKHEAD FORWARD CHORD - REPAIR [Group 1] . 140
FIGURE 17: LEFT SIDE - STA 2370 PIVOT BULKHEAD FORWARD CHORD - REPAIR [Group 2] . 161
FIGURE 18: RIGHT SIDE - STA 2370 PIVOT BULKHEAD FORWARD CHORD - REPAIR [Group 2] . 181
FIGURE 19: LEFT SIDE - STA 2370 PIVOT BULKHEAD FORWARD CHORD - POST-REPAIR DET AND
HFEC INSPECTION ..................................... 2 0 1
FIGURE 20: RIGHT SIDE - STA 2370 PIVOT BULKHEAD FORWARD CHORD - POST-REPAIR DET AND
HFEC INSPECTION ..................................... 2 0 4
FIGURE 21: LEFT SIDE - STA 2370 PIVOT BULKHEAD FORWARD CHORD POST-REPAIR INSPECTION
- SKIN PANEL INSTALLATION ............................... 2 0 7
FIGURE 22: RIGHT SIDE - STA 2370 PIVOT BULKHEAD FORWARD CHORD POST-REPAIR INSPECTION
- SKIN PANEL INSTALLATION ............................... 2 1 2
FIGURE 23: LEFT SIDE - STA 2370 PIVOT BULKHEAD FORWARD CHORD POST-REPAIR - SKIN PANEL
INSTALLATION ........................................ 2 1 7
FIGURE 24: RIGHT SIDE - STA 2370 PIVOT BULKHEAD FORWARD CHORD POST-REPAIR - SKIN PANEL
INSTALLATION ........................................ 2 2 2
APPENDIX A: LOGIC DIAGRAM FOR PARAGRAPH 1.E., COMPLIANCE: TABLE 1: DETAILED AND HFEC
INSPECTION OF THE STATION 2370 PIVOT BULKHEAD FORWARD CHORD .... 2 2 7
APPENDIX B: LOGIC DIAGRAM FOR PARAGRAPH 1.E., COMPLIANCE: TABLE 2: POST-REPAIR DETAILED
AND HFEC INSPECTION OF THE STATION 2370 PIVOT BULKHEAD FORWARD CHORD
................................................. 2 3 0
APPENDIX C: BOEING PART DEMAND INTENT .............................. 2 3 2
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Commercial 
Airplanes
777
Service Bulletin
ALERT
SummaryNumber: 777-53A0075Original Issue: January 14, 2015
ATA System: 5380
SUBJECT: FUSELAGE - Section 48 - Station 2370 Pivot Bulkhead Forward Outer Chord -
Inspection and Repair
THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH
1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO
THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO
THE NEW OWNER.
CONCURRENT REQUIREMENTS
None.
BACKGROUND
This service bulletin is sent to give instructions for inspections of the left and right side forward outer chords of
the Body Station (STA) 2370 pivot bulkhead for cracks. Cracks in the STA 2370 pivot bulkhead forward outer
chords that are not found and repaired can become large and result in a severed forward outer chord. Since
the horizontal stabilizer is attached to the STA 2370 bulkhead at two pivot locations, this damage could result
in the loss of horizontal stabilizer control.
One operator reported finding cracks in the outer flanges of the left and right side forward outer chords of the
STA 2370 pivot bulkhead on three airplanes. The cracks were fatigue cracks caused by a stress concentration
which is generated at the transition radius of the forward outer flange of the chord prior to the chord splice at
the upper longeron. Cracks were found on three 777-200 airplanes with 31,384 flight cycles (39,142 flight hours),
31,504 flight cycles (39,797 flight hours) and 32,181 flight cycles (38,758 flight hours).
Accomplishment of the inspections in this service bulletin will help ensure that STA 2370 pivot bulkhead forward
outer chord cracks are found and repaired before they can become large and result in damage that could result
in the loss of horizontal stabilizer control.
Boeing Service Bulletin (SB) 777-53-0076 gives instructions for a modification that is terminating action to the
repeat inspections given in this service bulletin.
Boeing Fleet Team Digest (FTD) 777 FTD 53-13001 is related to this service bulletin.
Boeing Service Related Problem (SRP) 777-SRP-53-0455 is related to this service bulletin.
This table is provided to operators for planning purposes only. Refer to the applicable sections for more
information.
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ReferenceAffectedPlanning Data
Paragraph 1.A.2., Spares AffectedNoSpares Affected
Paragraph 1.E., Compliance and Paragraph
1.F., Approval
YesAD Related
Paragraph 1.H., Weight and Balance ChangesYes (a)Weight 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 Air-
plane 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
(a) Only if the repair was done.
ACTION (PRR 62777-97S)
Do a Detailed and HFEC inspection of the Station 2370 pivot bulkhead forward chord in accordance with Part
1, for any crack.
If any crack is found, and any crack found is less than or equal to 0.160 inch, do one of the following options on
the affected side of the airplane:
1. Do the terminating action in accordance with SB 777-53-0076.
2. Do the repair of the Station 2370 pivot bulkhead forward chord in accordance with PART 2 and the
post-repair Detailed and HFEC inspection in accordance with PART 3.
If any crack is found, and any crack found is greater than 0.160 inch, do the terminating action in accordance
with SB 777-53-0076.
EFFECTIVITY
777-200/-300 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 available for airplanes in warranty as of November 20, 2013. Please refer to
Paragraph 2.B., Industry Support Information. The warranty remedies will expire eight years from the original
issue date of this service bulletin.
MANPOWER
Elapsed HoursTotal Task HoursAirplanes
10.5014.50All Airplanes -
Inspection
24.0544.85Group 1 Air-
planes - Small
Crack Repair -
One Side of the
airplane
22.3043.10Group 2 Air-
planes - Small
Crack Repair -
One Side of the
airplane
8.5010.50All Airplanes -
Post-Repair In-
spection
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 C 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 777-53A0075
ALERT  ALERT
LEFT AND RIGHT SIDE:
DO A DETAILED AND HFEC INSPECTION OF THE
STATION 2370 PIVOT BULKHEAD FORWARD CHORD
STA  IN ACCORDANCE WITH PART 1, FOR ANY CRACK.
2370  IF ANY CRACK IS FOUND, AND ANY CRACK FOUND
S LESS THAN OR EQUAL TO 0.160 INCH, DO ONE
OF THE FOLLOWING OPTIONS ON THE AFFECTED
SIDE OF THE AIRPLANE:
1. DO THE TERMINATING ACTION IN
ACCORDANCE WITH SB 777-53-0076
2. DO THE REPAIR OF THE STATION 2370 PIVOT
BULKHEAD FORWARD CHORD IN ACCORDANCE
WITH PART 2, AND THE POST-REPAIR DETAILED
AND HFEC INSPECTION IN ACCORDANCE WITH
PART 3.
IF ANY CRACK IS FOUND, AND ANY CRACK FOUND
IS GREATER THAN 0.160 INCH, DO THE
TERMINATING ACTION IN ACCORDANCE WITH
SB 777-53-0076.
2357294
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Commercial 
Airplanes
777
Service Bulletin
ALERT
Number: 777-53A0075
Original Issue: January 14, 2015
ATA System: 5380
SUBJECT: FUSELAGE - Section 48 - Station 2370 Pivot Bulkhead Forward Outer Chord -
Inspection and Repair
THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH
1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO
THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO
THE NEW OWNER.
1.    PLANNING INFORMATION
A. Effectivity
1. Airplanes
This service bulletin is applicable to 777-200/-300 Airplanes, line numbers 1-244 in 2 Groups. The
Variable Numbers and Group Information for the applicable airplanes is given below. An equivalent
change is on subsequent production airplanes. Refer to PRR 62777-97S for data about this change.
Refer to Service Bulletin Index D624W001 Part 3 for Airplane Variable Number, Line Number, and
Serial Number data.
DESCRIPTIONCONFIGURATIONGROUP
777 Airplanes, line numbers 1 through 40-1
777 Airplanes, line numbers 41 through 244-2
Airplane Models:
777-200, 777-300
GroupVariable Number
1WA001 - WA017
1WA076 - WA080
1WA086 - WA087
2WA088 - WA093
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GroupVariable Number
1WA101 - WA104
1WA116 - WA117
2WA118 - WA119
1WA131 - WA135
2WA136 - WA137
1WA171 - WA173
2WA174 - WA175
1WA196 - WA197
2WA198
2WA206 - WA212
2WA221 - WA223
2WA231 - WA232
2WA241 - WA245
2WB001 - WB020
2WB031
2WB051 - WB072
2WB101 - WB106
2WB121 - WB125
2WB131 - WB133
2WB151 - WB153
2WB161 - WB171
2WB181 - WB188
2WB231 - WB235
2WB271 - WB272
2WB276 - WB286
2WB291 - WB297
2WB306 - WB307
2WB311 - WB318
2WB336 - WB337
2WB366
2WB371 - WB383
2WB406
2WB411 - WB413
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GroupVariable Number
2WB416 - WB426
2WB446 - WB448
2WB501 - WB506
2WB531 - WB535
2WB551 - WB553
2WB591 - WB595
2WB601 - WB602
2WB611 - WB615
2. Spares Affected
None.
B. Concurrent Requirements
None.
C. Reason
This service bulletin is sent to give instructions for inspections of the left and right side forward outer
chords of the Body Station (STA) 2370 pivot bulkhead for cracks. Cracks in the STA 2370 pivot bulkhead
forward outer chords that are not found and repaired can become large and result in a severed forward
outer chord. Since the horizontal stabilizer is attached to the STA 2370 bulkhead at two pivot locations,
this damage could result in the loss of horizontal stabilizer control.
One operator reported finding cracks in the outer flanges of the left and right side forward outer chords
of the STA 2370 pivot bulkhead on three airplanes. The cracks were caused by stress concentration
which is generated at the transition radius of the forward outer flange of the chord prior to the chord
splice at the upper longeron. Cracks were found on three 777-200 airplanes with 31,384 flight cycles
(39,142 flight hours), 31,504 flight cycles (39,797 flight hours) and 32,181 flight cycles (38,758 flight
hours).
Accomplishment of the inspections in this service bulletin will help ensure that STA 2370 pivot bulkhead
forward outer chord cracks are found and repaired before they can become large and result in damage
that could result in the loss of horizontal stabilizer control.
Boeing Service Bulletin (SB) 777-53-0076 gives instructions for a modification that is terminating action
to the repeat inspections given in this service bulletin.
Boeing Fleet Team Digest (FTD) 777 FTD 53-13001 is related to this service bulletin.
Boeing Service Related Problem (SRP) 777-SRP-53-0455 is related to this service bulletin.
D. Description
Do a Detailed and HFEC inspection of the Station 2370 pivot bulkhead forward chord in accordance
with Part 1, for any crack.
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If any crack is found, and any crack found is less than or equal to 0.160 inch, do one of the following
options on the affected side of the airplane:
1. Do the terminating action in accordance with SB 777-53-0076.
2. Do the repair of the Station 2370 pivot bulkhead forward chord in accordance with PART 2 and
the post-repair Detailed and HFEC inspection in accordance with PART 3.
If any crack is found, and any crack found is greater than 0.160 inch, do the terminating action in
accordance with SB 777-53-0076.
The work in this service bulletin is done in the maintenance zone(s) given below.
Group 1:
Affected Maintenance Zones
ZoneModel
313, 314777-200
Group 2:
Affected Maintenance Zones
ZoneModel
313, 314777-200, 777-300
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.
When more than one OPTION is given for a CONDITION, do only one of the OPTION numbers. When
more than one ACTION is given for a CONDITION number or an OPTION number, do all of the ACTION
numbers for that CONDITION number or OPTION number.
Logic diagrams showing compliance tasks and compliance times are included as aids in APPENDIX
A and APPENDIX B.
The conditions and associated actions given in the Compliance tables below can be different on the
left and right sides of the airplane. The inspections and actions must be done on both sides. Because
the conditions found may not be the same on both sides of the airplane, the required actions may be
different between the left and right side of the airplane. The actions done must obey the compliance
tables for each side of the airplane.
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Table 1: Detailed and HFEC Inspection of the Station 2370 Pivot Bulkhead Forward Chord:
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
-Within 4,000
flight cycles or
1,125 days,
whichever oc-
curs first, after
the Original Is-
sue date of this
Service Bulletin.
Before 16,000
total flight cycles
Do PART 1: STATION
2370 PIVOT BULKHEAD
FORWARD CHORD -
DET AND HFEC INSPEC-
TION for any crack.
All Airplanes
12,000 flight cycles--OPTION 1:CONDITION 1: NO FOR-
WARD CHORD CRACK IS
FOUND
(a)Repeat PART 1: STA-
TION 2370 PIVOT
BULKHEAD FORWARD
CHORD - DET AND
HFEC INSPECTION for
any crack.
(a)Before further flightOPTION 2:
Do the terminating modifi-
cation in accordance with
Boeing Service Bulletin
777-53-0076. (a)
Before further flightOPTION 2:CONDITION 2: ANY FOR-
WARD CHORD CRACK IS
FOUND, AND NO CRACK
FOUND IS GREATER
THAN 0.160 INCH.
Do the terminating modifi-
cation in accordance with
Boeing Service Bulletin
777-53-0076. (a)
-Before further flightOPTION 3, ACTION 1:
Do PART 2: STATION
2370 PIVOT BULKHEAD
FORWARD CHORD -
SMALL CRACK REPAIR
Refer to Table 2OPTION 3, ACTION 2:
Do PART 3: STATION
2370 PIVOT BULKHEAD
FORWARD CHORD -
POST-REPAIR DET AND
HFEC INSPECTION
-Before further flightDo the terminating modifi-
cation in accordance with
Boeing Service Bulletin
777-53-0076. (a)
CONDITION 3: ANY FOR-
WARD CHORD CRACK IS
FOUND, AND ANY
CRACK FOUND IS
GREATER THAN 0.160
INCH.
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Table 1: Detailed and HFEC Inspection of the Station 2370 Pivot Bulkhead Forward Chord:
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
-Before further flightContinue to do the small
crack repair in accor-
dance with PART 2:
STATION 2370 PIVOT
BULKHEAD FORWARD
CHORD - SMALL
CRACK REPAIR
CONDITION 6: NO FOR-
WARD CHORD UPPER
LOCATION OR ADJA-
CENT STRUCTURE
CRACK IS FOUND
-Before further flightACTION 1: Contact Boe-
ing for repair instructions
and do the repair.
CONDITION 7: ANY FOR-
WARD CHORD UPPER
LOCATION OR ADJA-
CENT STRUCTURE
CRACK IS FOUND -Before further flightACTION 2: Continue todo the small crack repair
in accordance with PART
2: STATION 2370 PIVOT
BULKHEAD FORWARD
CHORD - SMALL
CRACK REPAIR
(a) Modification in accordance with Boeing Service Bulletin 777-53-0076 is terminating action for the inspec-
tions in this service bulletin.
Table 2: Post-Repair Detailed and HFEC Inspection of the STA 2370 Pivot Bulkhead Forward
Chord:
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
-Within 12,000 flight
cycles after installa-
tion of the repair in
accordance with
PART 2: STATION
2370 PIVOT
BULKHEAD FOR-
WARD CHORD -
SMALL CRACK
REPAIR
Do PART 3: STATION
2370 PIVOT BULKHEAD
FORWARD CHORD -
POST-REPAIR DET AND
HFEC INSPECTION for
any crack.
All airplanes previously re-
paired in accordance with
PART 2: STATION 2370
PIVOT BULKHEAD FOR-
WARD CHORD - SMALL
CRACK REPAIR
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Table 2: Post-Repair Detailed and HFEC Inspection of the STA 2370 Pivot Bulkhead Forward
Chord:
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
12,000 flight cycles-OPTION 4: Repeat PART
3: STATION 2370 PIVOT
BULKHEAD FORWARD
CHORD -POST-REPAIR
DET AND HFEC INSPEC-
TION for any crack.
CONDITION 4: NO FOR-
WARD CHORD CRACK IS
FOUND DURING POST-
REPAIR INSPECTION
(a)
(a)Before further flightOPTION 2: Do the termi-
nating modification in ac-
cordance with Boeing
Service Bulletin 777-53-
0076. (a)
-Before further flightDo the terminating modifi-
cation in accordance with
Boeing Service Bulletin
777-53-0076. (a)
CONDITION 5: ANY FOR-
WARD CHORD CRACK IS
FOUND DURING POST-
REPAIR INSPECTION
(a) Modification in accordance with Boeing Service Bulletin 777-53-0076 is terminating action
for the inspections in this service bulletin.
NOTE: PART 1: STATION 2370 PIVOT BULKHEAD FORWARD CHORD - DET AND HFEC
INSPECTION is for both sides of the airplane.
PART 2: STATION 2370 PIVOT BULKHEAD FORWARD CHORD - SMALL CRACK REPAIR
is for one side of the airplane. It is possible to have an airplane with PART 2: STATION 2370
PIVOT BULKHEAD FORWARD CHORD - SMALL CRACK REPAIR done on both sides.
PART 3: STATION 2370 PIVOT BULKHEAD FORWARD CHORD - POST-REPAIR DET AND
HFEC INSPECTION is for one side of the airplane. It is possible to have an airplane with
PART 3: STATION 2370 PIVOT BULKHEAD FORWARD CHORD - POST-REPAIR DET AND
HFEC INSPECTION done on both sides.
PART 4: STATION 2370 PIVOT BULKHEAD FORWARD CHORD AND ADJACENT
STRUCTURE - HFEC AND DET INSPECTION is for one side of the airplane. It is possible
to have an airplane with PART 4: STATION 2370 PIVOT BULKHEAD FORWARD CHORD
AND ADJACENT STRUCTURE - HFEC AND DET INSPECTION done on both sides.
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.
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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 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.
Table 1: Manpower Information for PART 1: STATION 2370 PIVOT BULKHEAD FORWARD
CHORD - DET AND HFEC INSPECTION
Elapsed HoursTask HoursNumber of PersonsTask
Open Access
2.002.001.FIGURE 1
2,002.001.FIGURE 2
PART 1: STATION
2370 PIVOT BULK-
HEAD FORWARD
CHORD - DET AND
HFEC INSPECTION
1.251.251.FIGURE 3
1.251.251.FIGURE 4
Close Access
2.004.002.FIGURE 5
2.004.002.FIGURE 6
10.5014.50TOTAL FOR EACH AIRPLANE
Group 1:
Table 2: Manpower Information for PART 2: STATION 2370 PIVOT BULKHEAD FORWARD
CHORD - SMALL CRACK REPAIR
Elapsed HoursTask HoursNumber of PersonsTask
4.008.002FIGURE 7 (or FIG-
URE 8) (a)
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Group 1:
Table 2: Manpower Information for PART 2: STATION 2370 PIVOT BULKHEAD FORWARD
CHORD - SMALL CRACK REPAIR
Elapsed HoursTask HoursNumber of PersonsTask
1.501.501FIGURE 11 (or FIG-
URE 12) (a)
1.751.751FIGURE 13 (or FIG-
URE 14) (a)
14.8029.602FIGURE 15 (or FIG-
URE 16) (a)
2.004.002FIGURE 23 (or FIG-
URE 24) (a)
24.0544.85TOTAL FOR ONE SIDE OF THE AIRPLANE
(a) Use Figure 23 and/or Figure 24, as applicable, if the small crack repair in ac-
cordance with PART 2: STATION 2370 PIVOT BULKHEAD FORWARD
CHORD - SMALL CRACK REPAIR was done.
Group 2:
Table 3: Manpower Information for PART 2: STATION 2370 PIVOT BULKHEAD FORWARD
CHORD - SMALL CRACK REPAIR
Elapsed HoursTask HoursNumber of PersonsTask
4.008.002FIGURE 9 (or FIG-
URE 10) (a)
1.501.501FIGURE 11 (or FIG-
URE 12) (a)
14.8029.602FIGURE 17 (or FIG-
URE 18) (a)
2.004.002FIGURE 23 (or FIG-
URE 24) (a), (b)
22.3043.10TOTAL FOR ONE SIDE OF THE AIRPLANE
(a)
(a) This table shows the manpower information for small crack repair in accordance
with PART 2: STATION 2370 PIVOT BULKHEAD FORWARD CHORD -
SMALL CRACK REPAIR, on one side of the airplane. If both sides of the air-
plane are repaired in accordance with PART 2: STATION 2370 PIVOT
BULKHEAD FORWARD CHORD - SMALL CRACK REPAIR, multiply the total
manpower information by two, to obtain the total manpower for both sides of
the airplane.
(b) Use Figure 23 and/or Figure 24, as applicable, if the small crack repair in ac-
cordance with PART 2: STATION 2370 PIVOT BULKHEAD FORWARD
CHORD - SMALL CRACK REPAIR was done.
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Table 4: Manpower Information for PART 3: STATION 2370 PIVOT BULKHEAD FORWARD
CHORD - POST-REPAIR DET AND HFEC INSPECTION
Elapsed HoursTask HoursNumber of PersonsTask
Open Access
2.002.001.FIGURE 1
2.002.001.FIGURE 2
DET and HFEC In-
spection
1.251.251.FIGURE 19
1.251.251.FIGURE 20
Close Access
2.002.002.FIGURE 21
2.002,002.FIGURE 22
8.5010.50TOTAL FOR EACH AIRPLANE
NOTE: PART 1: STATION 2370 PIVOT BULKHEAD FORWARD CHORD - DET AND HFEC
INSPECTION is for both sides of the airplane.
PART 2: STATION 2370 PIVOT BULKHEAD FORWARD CHORD - SMALL CRACK REPAIR
is for one side of the airplane. It is possible to have an airplane with PART 2: STATION 2370
PIVOT BULKHEAD FORWARD CHORD - SMALL CRACK REPAIR done on both sides.
PART 3: STATION 2370 PIVOT BULKHEAD FORWARD CHORD - POST-REPAIR DET AND
HFEC INSPECTION is for one side of the airplane. It is possible to have an airplane with
PART 3: STATION 2370 PIVOT BULKHEAD FORWARD CHORD - POST-REPAIR DET AND
HFEC INSPECTION done on both sides.
PART 4: STATION 2370 PIVOT BULKHEAD FORWARD CHORD AND ADJACENT
STRUCTURE - HFEC AND DET INSPECTION is for one side of the airplane. It is possible
to have an airplane with PART 4: STATION 2370 PIVOT BULKHEAD FORWARD CHORD
AND ADJACENT STRUCTURE - HFEC AND DET INSPECTION done on both sides.
H. Weight and Balance Changes
Change in Moment
(Pound-Inches)
Change in Weight
(Pounds)Airplane
(a)(a)777-200 - Repaired
on one side
(a)(a)777-200 - Repaired
on both sides
(a)(a)777-300 - Repaired
on one side
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Change in Moment
(Pound-Inches)
Change in Weight
(Pounds)Airplane
(a)(a)777-200 - Repaired
on both sides
(a) This information was not available at the Original Issue date
of this service bulletin.
I. Electrical Load Data
Not changed.
J. References
1. Existing Data:
a. Engineering Change Memo PRR 62777-97S
b. Boeing Service Letter 777-SL-51-013
c. Boeing Service Related Problem (SRP) 777-SRP-53-0455
d. Service Bulletin Index D624W001
e. Standard Overhaul Practices Manual (SOPM) 20-10-03, 20-41-02, 20-41-05, 20-43-03,
20-50-01, 20-50-10, 20-50-19
f. Standard Wiring Practices Manual (SWPM) 20-10-11, 20-10-12, 20-10-19
g. 777 Aircraft Maintenance Manual (AMM) 07-11-01, 55-17-01
h. 777 Fleet Team Digest (FTD) 53-13001
i. 777 Non-Destructive Testing (NDT) Manual Part 6, 51-00-01, Part 6, 51-00-02
j. 777-200 Structural Repair Manual (SRM) 51-10-02, 51-20-01
k. 777-300 Structural Repair Manual (SRM) 51-10-02, 51-20-01
2. Data Supplied with this Service Bulletin:
None.
3. Installation Drawings Used in the Preparation of this Service Bulletin:
TitleDrawing Number
Bulkhead Instl - Upr, Pivot and Skin, STA 2370148W2010
Fairing Instl - Stabilizer Seal, UPR148W2910
Bulkhead Instl - Pivot, Integration, STA 2370148W9700
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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
53-80777 Structural Repair Manual
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. DTI requirements for the structure affected
are contained in Paragraph 1.E., Compliance of this service bulletin.
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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2.    MATERIAL INFORMATION
A. Material - Price and Availability
Boeing can supply the kits 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 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
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 original issue
date of this Ser-
vice Bulletin (US
Dollars)
ROLT as of the
original issue
date of this Ser-
vice Bulletin (Cal-
endar Days)
QTYDateNameKit Number
(c)(c)(c)(c)Top Kit - STA 2370
Pivot Bulkhead Forward
Outer Chord - Inspec-
tion Restoration
005W0016-10
(c)(c)(c)(c)Top Kit - STA 2370
Pivot Bulkhead Forward
Outer Chord, Left -
Small Crack
005W0016-11
(a)
(c)(c)(c)(c)Top Kit - STA 2370
Pivot Bulkhead Forward
Outer Chord, Right -
Small Crack
005W0016-12
(b)
(a) This top kit is for the repair on the left side of the airplane.
(b) This top kit is for the repair on the right side of the airplane.
(c) This information was not available at the Original Issue date of this service bulletin.
Operators are encouraged to complete the survey provided in APPENDIX C of this service bulletin to
help Boeing predict the quantity and timing of the Boeing Supplied Kits/Parts.
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B. Industry Support Information
Boeing warranty remedies are available for 777 airplanes in warranty as of November 20, 2013. For
task hour reimbursement for airplanes in warranty as of that date, send a warranty claim to Boeing
Fleet Support Contracts - Warranty. The kits for airplanes in warranty as of that date will be supplied
at no charge. Send a purchase order for the kits to Boeing Material Management. Please refer to this
service bulletin number and reference the airplane variable numbers in your purchase order. The
warranty remedies will expire eight years from the original issue date of 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, except as noted in Paragraph 2.A., Material
- Price and Availability.
NOTE: For some fasteners, there are more parts than are necessary. If grip length shown is not
available at Boeing, fasteners supplied in kits may be one grip length longer than indicated.
Also, if any fasteners part numbers listed are not available or have been superseded,
substitute fasteners may be supplied in kits.
ALL
Kit 005W0016
NotesExisting Part
Number
NameQtyNew Part Number
-12-11-10
(a)Top Kit - STA 2370
Pivot Bulkhead
Forward Outer
Chord - Inspection
Restoration
..-005W0016-10
(b)Top Kit - STA 2370
Pivot Bulkhead
Forward Outer
Chord, Left - Small
Crack Repair
.-.005W0016-11
(c)Top Kit - STA 2370
Pivot Bulkhead
Forward Outer
Chord, Right- Small
Crack Repair
-..005W0016-12
SHIM11.148W0015-12
SHIM11.148W0015-13
SHIM22.148W0015-14
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ALL
Kit 005W0016
NotesExisting Part
Number
NameQtyNew Part Number
-12-11-10
(d) (e)
(f)
148W2204-1
(Group 1)
SPLICE ANGLE.1.148W2204-5
148W2204-3
(Group 2)
(d) (e)
(f)
148W2204-2
(Group 1)
SPLICE ANGLE1..148W2204-6
148W2204-4
(Group 1)
SHIM LAMINATED11.148W7143-5
SHIM LAMINATED11.148W7143-6
SHIM LAMINATED11.148W7143-7
SHIM LAMINATED11.148W7143-11
SHIM LAMINATED11.148W7143-13
BOLT, PROTRUD-
ING HD
77.BACB30MY10K10X
BOLT, PROTRUD-
ING HD
77.BACB30MY10K13X
BOLT, PROTRUD-
ING HD
99.BACB30MY10K7X
BOLT, PROTRUD-
ING HD
1515.BACB30MY8K11X
BOLT, PROTRUD-
ING HD
1515.BACB30MY8K4X
BOLT, PROTRUD-
ING HD
1414.BACB30MY8K5X
BOLT, PROTRUD-
ING HD
2020.BACB30MY8K6X
BOLT, PROTRUD-
ING HD
99.BACB30MY8K7X
BOLT, PROTRUD-
ING HD
66.BACB30MY8K8X
BOLT, PROTRUD-
ING HD
11.BACB30MY8K9X
BOLT, 100 DEG
HEX DR
666BACB30NW6K5X
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### Page 24

ALL
Kit 005W0016
NotesExisting Part
Number
NameQtyNew Part Number
-12-11-10
BOLT, 100 DEG
HEX DR
3131.BACB30NW8K10X
BOLT, 100 DEG
HEX DR
22.BACB30NW8K12X
BOLT, 100 DEG
HEX DR
161616BACB30NW8K5X
BOLT, 100 DEG
HEX DR
..6BACB30NW8K5Y
BOLT, 100 DEG
HEX DR
444BACB30NW8K6X
BOLT, 100 DEG
HEX DR
..2BACB30NW8K6Y
BOLT, 100 DEG
HEX DR
33.BACB30NW8K7X
BOLT, 100 DEG
HEX DR
66.BACB30NW8K8X
BOLT, 100 DEG
HEX DR
101010BACB30NW8K9X
BOLT, 100 DEG
HEX DR
..4BACB30NW8K9Y
BOLT, PROTRUD-
ING HD
33.BACB30NX10K11X
BOLT, PROTRUD-
ING HD
1414.BACB30NX10K14X
BOLT, PROTRUD-
ING HD
44.BACB30NX6K5X
BOLT, 100 DEG
HEX D
1313.BACB30NZ10K15X
BOLT, 100 DEG
HEX DR
1717.BACB30NZ10K16X
BOLT, 100 DEG
HEX DR
1111.BACB30NZ8K12X
BOLT, HEX DRIVE1313.BACB30YN10K15X
BOLT, HEX DRIVE1717.BACB30YN10K16X
BOLT, HEX DRIVE99.BACB30YN8K12X
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ALL
Kit 005W0016
NotesExisting Part
Number
NameQtyNew Part Number
-12-11-10
COLLAR4848.BACC30BH10
COLLAR1111.BACC30BH8
COLLAR2222.BACC30M10
COLLAR666BACC30M6
COLLAR303030BACC30M8
COLLAR..12BACC30R8
SELF-LOCKING
NUT
22.BACN10HR12CD
SELF-LOCKING
NUT
22.BACN10HR162CD
SELF-LOCKING
NUT
66.BACN10HR6CD
NUT33.BACN10HR8CD
NUT1818.BACN10YR4CD
NUT3434.BACN10YR5CD
NUT55.BACN11AK5C
RIVET, 100 DEG666BACR15CE5KE5
RIVET, 100 DEG121212BACR15CE5KE6
RIVET, 100 DEG222BACR15CE5KE8
RIVET3131.BACR15FV81KE13
SHIM, LAMINAT-
ED
11.BACS40R007B064F
SHIM, LAMINAT-
ED
11.BACS40R007B077F
SHIM, LAMINAT-
ED
11.BACS40R008B041F
SHIM, LAMINAT-
ED
11.BACS40R008B062F
SHIM, LAMINAT-
ED
11.BACS40R016B037F
SHIM, LAMINAT-
ED
11.BACS40R017B037F
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### Page 26

ALL
Kit 005W0016
NotesExisting Part
Number
NameQtyNew Part Number
-12-11-10
SHIM, LAMINAT-
ED
11.BACS40R019B056F
SHIM, LAMINAT-
ED
11.BACS40R021B049F
SHIM, LAMINAT-
ED
11.BACS40R023B053F
TAPERED SHIM22.BACS40R026B051F
SHIM,LAMINATED11.BACS40R029B065F
SHIM-LAMINATED11.BACS40R033B052F
SHIM22.BACS40R037B052F
WASHER, PLAIN22.BACW10BP12CD
WASHER, PLAIN22.BACW10BP12DP
WASHER, PLAIN22.BACW10BP16CD
WASHER, PLAIN22.BACW10BP16DP
WASHER, PLAIN99.BACW10BP41DP
WASHER, PLAIN66.BACW10BP6CD
WASHER66.BACW10BP6DP
WASHER33.BACW10BP8CD
WASHER33.BACW10BP8DP
WASHER2020.NAS1149D0432J
WASHER, PLAIN1010.NAS1149D0463K
WASHER, PLAIN3030.NAS1149D0532K
WASHER3030.NAS1149D0563J
(a) This top kit is for access restoration after inspection and no crack findings.
(b) This top kit is for the repair on the left side of the airplane.
(c) This top kit is for the repair on the right side of the airplane.
(d) Discard the existing part.
(e) This part is used in production.
(f) You cannot use the existing part to replace the new or changed part.
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### Page 27

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.
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)Corrosion Inhibiting Compound1 pintBMS 3-23 (BMS 3-
29 and BMS 3-35
optional)
(a)Sealant1 pintBMS 5-95
(a)Primer1 pintBMS 10-11, Type I
(a) Refer to the Qualified Products List at the end of the Boeing Material Specification (BMS)
for supplier data.
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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### Page 29

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
Airplane Maintenance Manual (AMM).
— Values for electrical maintenance tasks are included in Chapter 20 of
Standard Wiring Practices Manual (SWPM).
— Values for engine maintenance tasks are included in Chapter 70 of 777
Airplane Maintenance Manual (AMM).
— Non-standard torque values for maintenance tasks are included in the
applicable installation step.
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.
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7. If the length of any fastener specified in this service bulletin does not meet installation
standards given in SRM Chapter 51, then a fastener of the same specification, or
an approved substitute, with a length which meets the installation standards given
in SRM Chapter 51 may be used. In addition, washers may be installed for fastener
grip length in accordance with SRM Chapter 51. Refer to SOPM 20-50-01 for alternate
full threaded fasteners (screws) needed for installation in this service bulletin.
8. 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.
9. HFEC is used for a High Frequency Eddy Current Inspection.
10. 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.
11. Boeing Service Letter 777-SL-51-013, Damage Reporting and Repair Plan/Design
Guidelines, is an acceptable procedure to request information from Boeing for
additional structural repair instructions. The Service Letter describes what information
must be provided to Boeing before a structural repair can be provided.
12. Refer to APPENDIX A and APPENDIX B 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.
13. 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.
14. 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.
15. 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.
16. If shading is used, shaded areas in Figures are to separate the non-critical and
non-authoritative information from the critical and authoritative information.
17. Use of colors in Figures is based on guidance from the ATA e-Business Program
(ATA) iSpec 2200.
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### Page 31

18. When more than one OPTION is given for a CONDITION, do only one of the OPTION
numbers. When more than one ACTION is given for a CONDITION number or an
OPTION number, do all of the ACTION numbers for that CONDITION number or
OPTION number.
19. The compliance times for the actions in Paragraph 3.B., WORK INSTRUCTIONS
are in Paragraph 1.E., Compliance.
20. The CONDITIONS, ACTIONS and OPTIONS shown apply to each side independently.
21. The conditions, actions and associated actions given in the work instructions can be
different on the left and right sides of the airplane. The work instructions given in this
service bulletin are to be accomplished on both sides of the airplane independently.
22. Some steps in the Work Instructions are identified as Required for Compliance (RC).
If this service bulletin is mandated by an Airworthiness Directive (AD), then the steps
identified as RC must be done to comply with the AD. Alternative procedures for
steps not identified with RC can be used if the RC steps can still be done as specified,
and the airplane can be put back in a serviceable condition. An Alternative Method
of Compliance (AMOC) is not necessary for deviations to steps that are not identified
as RC.
B. WORK INSTRUCTIONS
1. Remove the skin panels in accordance with the figures below:
Right SideLeft Side
FIGURE 2FIGURE 1
2. Do PART 1: STATION 2370 PIVOT BULKHEAD FORWARD CHORD - DET AND HFEC
INSPECTION, for any crack.
a. CONDITION 1: NO FORWARD CHORD CRACK IS FOUND
(1) OPTION 1: Repeat PART 1: STATION 2370 PIVOT BULKHEAD FORWARD CHORD -
DET AND HFEC INSPECTION.
(2) OPTION 2: Do the terminating modification in accordance with Boeing Service Bulletin
777-53-0076.
b. CONDITION 2: ANY FORWARD CHORD CRACK IS FOUND, AND NO CRACK FOUND IS
GREATER THAN 0.160 INCH
(1) OPTION 2: Do the terminating modification in accordance with Boeing Service Bulletin
777-53-0076.
(2) OPTION 3:
(a) OPTION 3 (ACTION 1): Do PART 2: STATION 2370 PIVOT BULKHEAD FORWARD
CHORD - SMALL CRACK REPAIR.
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### Page 32

(b) OPTION 3 (ACTION 2): Do PART 3: STATION 2370 PIVOT BULKHEAD FORWARD
CHORD - POST-REPAIR DET AND HFEC INSPECTION.
1) CONDITION 4: NO FORWARD CHORD CRACK IS FOUND DURING
POST-REPAIR INSPECTION
a) OPTION 4: Repeat PART 3: STATION 2370 PIVOT BULKHEAD FORWARD
CHORD - POST-REPAIR DET AND HFEC INSPECTION.
b) OPTION 2: Do the terminating modification in accordance with Boeing
Service Bulletin 777-53-0076.
2) CONDITION 5: ANY FORWARD CHORD CRACK IS FOUND DURING
POST-REPAIR INSPECTION
a) Do the terminating modification in accordance with Boeing Service Bulletin
777-53-0076.
c. CONDITION 3: ANY FORWARD CHORD CRACK IS FOUND, AND ANY CRACK FOUND
IS GREATER THAN 0.160 INCH
(1) Do the terminating modification in accordance with Boeing Service Bulletin 777-53-0076.
3. If not previously installed, install the skin panels in accordance with the figures below:
Right SideLeft Side
FIGURE 6FIGURE 5
4. Put the airplane back to a serviceable condition.
PART 1: STATION 2370 PIVOT BULKHEAD FORWARD CHORD - DET AND HFEC INSPECTION
1. RC - Do an inspection of the Pivot Bulkhead Forward Outer Chord, for any crack, in accordance
with the figures below:
Right SideLeft Side
FIGURE 4FIGURE 3
PART 2: STATION 2370 PIVOT BULKHEAD FORWARD CHORD - SMALL CRACK REPAIR
1. Support the airplane using one of the options below:
OPTION 1:
a. Support the airplane on its landing gear.
b. Do internal shoring of the horizontal stabilizer on the rework side. Refer to 777 AMM 55-17-01,
Horizontal Stabilizer Pivot Pin Assembly Removal, as an accepted procedure.
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### Page 33

OPTION 2:
a. Lift the airplane on the primary jacks A, B and C. Refer to 777 AMM 07-11-01 as an accepted
procedure.
b. Do internal shoring of the horizontal stabilizer on the rework side. Refer to 777 AMM 55-17-01,
Horizontal Stabilizer Pivot Pin Assembly Removal, as an accepted procedure.
2. Group 1:
RC - Get access to the repair area in accordance with the figures below:
Right SideLeft Side
FIGURE 8FIGURE 7
3. Group 2:
RC - Get access to the repair area in accordance with the figures below:
Right SideLeft Side
FIGURE 10FIGURE 9
4. RC - Do PART 4: STATION 2370 PIVOT BULKHEAD FORWARD CHORD AND ADJACENT
STRUCTURE - HFEC AND DET INSPECTION, for any crack.
a. CONDITION 6: NO FORWARD CHORD UPPER LOCATION OR ADJACENT STRUCTURE
CRACK IS FOUND
(1) No action is required.
b. CONDITION 7: ANY FORWARD CHORD UPPER LOCATION OR ADJACENT STRUCTURE
CRACK IS FOUND
(1) RC - Contact Boeing for repair instructions and do the repair.
5. Group 1:
RC - Modify the splice angle in accordance with the figures below:
Right SideLeft Side
FIGURE 14FIGURE 13
6. Group 1:
RC - Repair the Station 2370 pivot bulkhead forward chord in accordance with the figures below:
Right SideLeft Side
FIGURE 16FIGURE 15
7. Group 2:
RC - Repair the Station 2370 pivot bulkhead forward chord in accordance with the figures below:
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### Page 34

Right SideLeft Side
FIGURE 18FIGURE 17
8. RC - Install the skin panels in accordance with the figures below:
Right SideLeft Side
FIGURE 24FIGURE 23
9. Apply finish to the repaired area to match adjacent structure. Apply BMS 3-23 (BMS 3-29 and
BMS 3-35 optional) corrosion inhibiting compound to the repaired area. Refer to SOPM 20-41-05
as an accepted procedure.
10. If the airplane was stabilized using OPTION 1, install the horizontal stabilizer pivot pin assembly
on the rework side. Refer to 777 AMM 55-17-01, Horizontal Stabilizer Pivot Pin Assembly
Installation, as an accepted procedure.
11. If the airplane was stabilized using OPTION 2,
a. Install the horizontal stabilizer pivot pin assembly on the rework side. Refer to 777 AMM
55-17-01, Horizontal Stabilizer Pivot Pin Assembly Installation, as an accepted procedure.
b. Lower the airplane off of the jacks. Refer to 777 AMM 07-11-01 as an accepted procedure.
PART 3: STATION 2370 PIVOT BULKHEAD FORWARD CHORD - POST-REPAIR DET AND HFEC
INSPECTION
1. RC - Remove the skin panels in accordance with the figures below:
Right SideLeft Side
FIGURE 2FIGURE 1
2. RC - Do the DET and HFEC inspection in accordance with the figures below:
Right SideLeft Side
FIGURE 20FIGURE 19
3. RC - Install the skin panels in accordance with the figures below:
Right SideLeft Side
FIGURE 22FIGURE 21
4. Put the airplane back to a serviceable condition.
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### Page 35

PART 4: STATION 2370 PIVOT BULKHEAD FORWARD CHORD AND ADJACENT STRUCTURE
- HFEC AND DET INSPECTION
1. RC - Inspect the pivot bulkhead forward chord and adjacent structure in accordance with the figures
below:
Right SideLeft Side
FIGURE 12FIGURE 11
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### Page 36 (OCR)

BOEING SERVICE BULLETIN 777-53A0075
ALERT  ALERT
STA
2370
SPLICE
PLATE
FILLER (2
FILLER (2
SKIN 2
BRACKET 2)  FILLER
ANGLE  FILLER  (2) SKIN  2356115
FIGURE 1: LEFT SIDE - STA 2370 SKIN PANEL REMOVAL
(SHEET 1 OF 4)
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### Page 37 (OCR)

BOEING SERVICE BULLETIN 777-53A0075
ALERT  ALERT
STA
2370
STA
2362.75
1) 12 LOCATIONS
10 LOCATIONS 1
- FWD
A-A  2356615
FIGURE 1: LEFT SIDE - STA 2370 SKIN PANEL REMOVAL
(SHEET 2 OF 4)
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### Page 38 (OCR)

BOEING SERVICE BULLETIN 777-53A0075
ALERT  ALERT
_GUSSET
_ BRACKET  2 BRACKET
1 SPLICE PLATE
SKIN
FWD
B-B
ANGLE (2  CHORD.
(2) BRACKET
© FILLER
1 SKIN
FWD
TYPICAL
C-C  2356494
FIGURE 1: LEFT SIDE - STA 2370 SKIN PANEL REMOVAL
(SHEET 3 OF 4)
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### Page 39

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 this figure.
More DataQtyIdentificationNameTaskStep
24-FASTENERRemove1
3-FASTENERRemove/Keep2
1148W2912-1SKIN
1148W2912-3SKIN
1148W2917-9FILLER
1148W2917-11FILLER
1148W2917-7FILLER
1148W2914-()ANGLE - FAIRING
ASSY, UPPER
1BACF3T03M14S8BFILLER
1148W2918-3SPLICE PLATE
1148W2920-1BRACKET
FIGURE 1: LEFT SIDE - STA 2370 SKIN PANEL REMOVAL
(SHEET 4 OF 4)
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ALERTALERT

### Page 40 (OCR)

BOEING SERVICE BULLETIN 777-53A0075
ALERT  ALERT
STA
2370
2) PLATE  SPLICE
(2) FILLER
2) FILLER
2) SKIN
FILLER  (2) BRACKET
SKIN 2  → FILLER  ANGLE  2357492
FIGURE 2: RIGHT SIDE - STA 2370 SKIN PANEL REMOVAL
(SHEET 1 OF 4)
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### Page 41 (OCR)

BOEING SERVICE BULLETIN 777-53A0075
ALERT  ALERT
STA
2370  2
STA
2362.75
12 LOCATIONS
) 10 LOCATIONS
FWD
A-A  2357535
FIGURE 2: RIGHT SIDE - STA 2370 SKIN PANEL REMOVAL
(SHEET 2 OF 4)
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### Page 42 (OCR)

BOEING SERVICE BULLETIN 777-53A0075
ALERT  ALERT
GUSSET.
BRACKET (2  BRACKET•
SPLICE PLATE (2
SKIN
FWD
B-B
CHORD  2) ANGLE  BRACKET 2
FILLERO
SKIN 2
FWD
TYPICAL
C-C
FIGURE 2: RIGHT SIDE - STA 2370 SKIN PANEL REMOVAL
(SHEET 3 OF 4)
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### Page 43

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 this figure.
More DataQtyIdentificationNameTaskStep
24-FASTENERRemove1
3-FASTENERRemove/Keep2
1148W2912-2SKIN
1148W2912-4SKIN
1148W2917-9FILLER
1148W2917-11FILLER
1148W2917-7FILLER
1148W2914-()ANGLE - FAIRING
ASSY, UPPER
1BACF3T03M14S8BFILLER
1148W2918-4SPLICE PLATE
1148W2920-2BRACKET
FIGURE 2: RIGHT SIDE - STA 2370 SKIN PANEL REMOVAL
(SHEET 4 OF 4)
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ALERTALERT

### Page 44 (OCR)

BOEING SERVICE BULLETIN 777-53A0075
ALERT  ALERT
STA
2370
• S-17L
A
2385532
FIGURE 3: LEFT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD - DET AND HFEC
INSPECTION
(SHEET 1 OF 4)
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### Page 45 (OCR)

BOEING SERVICE BULLETIN 777-53A0075
ALERT  ALERT
_ CHORD
0.53
0.47
0.53
0.47
STA
2362.75
—  +
—
INSPECTION  A-A  2358099
AREA
FIGURE 3: LEFT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD - DET AND HFEC
INSPECTION
(SHEET 2 OF 4)
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### Page 46

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 this figure.
More DataQtyIdentificationNameTaskStep
Do a DET for any crack.1148W7102-()CHORD - FOR-
WARD, PIVOT
BULKHEAD, MID
Inspect1
FIGURE 3: LEFT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD - DET AND HFEC
INSPECTION
(SHEET 3 OF 4)
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ALERTALERT

### Page 47

More DataQtyIdentificationNameTaskStep
Do a DET for any crack.1148W7102-()CHORD - FOR-
WARD, PIVOT
BULKHEAD, MID
Inspect2
Do an open hole HFEC inspection for
any crack, in accordance with 777 NDT
Manual Part 6, 51-00-02.
1148W7102-()CHORD - FOR-
WARD, PIVOT
BULKHEAD, MID
Inspect3
Do a surface HFEC inspection for any
crack, in accordance with 777 NDT
Manual Part 6, 51-00-01.
1148W7102-()CHORD - FOR-
WARD, PIVOT
BULKHEAD, MID
Inspect4
FIGURE 3: LEFT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD - DET AND HFEC
INSPECTION
(SHEET 4 OF 4)
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### Page 48 (OCR)

BOEING SERVICE BULLETIN 777-53A0075
ALERT  ALERT
STA
2370
S-17R •
2358103
FIGURE 4: RIGHT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD - DET AND HFEC
INSPECTION
(SHEET 1 OF 4)
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### Page 49 (OCR)

BOEING SERVICE BULLETIN 777-53A0075
ALERT  ALERT
CHORD
0.53
0.47
STA
2370  (3)  0,53
STA
2362.75
FWD
INSPECTION
A-A  AREA  2358104
FIGURE 4: RIGHT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD - DET AND HFEC
INSPECTION
(SHEET 2 OF 4)
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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 this figure.
More DataQtyIdentificationNameTaskStep
Do a DET for any crack.1148W7102-()CHORD - FOR-
WARD, PIVOT
BULKHEAD, MID
Inspect1
FIGURE 4: RIGHT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD - DET AND HFEC
INSPECTION
(SHEET 3 OF 4)
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ALERTALERT

### Page 51

More DataQtyIdentificationNameTaskStep
Do a DET for any crack.1148W7102-()CHORD - FOR-
WARD, PIVOT
BULKHEAD, MID
Inspect2
Do an open hole HFEC inspection for
any crack, in accordance with 777 NDT
Manual Part 6, 51-00-02.
1148W7102-()CHORD - FOR-
WARD, PIVOT
BULKHEAD, MID
Inspect3
Do a surface HFEC inspection for any
crack, in accordance with 777 NDT
Manual Part 6, 51-00-01.
1148W7102-()CHORD - FOR-
WARD, PIVOT
BULKHEAD, MID
Inspect4
FIGURE 4: RIGHT SIDE - STA 2370 PIVOT BULKHEAD FORWARD OUTER CHORD - DET AND HFEC
INSPECTION
(SHEET 4 OF 4)
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ALERTALERT

### Page 52 (OCR)

BOEING SERVICE BULLETIN 777-53A0075
ALERT  ALERT
STA
2370
SPLICE PLATE
( 3'
FILLER
1€3
FILLER
12 3
12) 3) SKIN
BRACKET  12)
ANGLE  FILLER  SKIN 123
FIGURE 5: LEFT SIDE - STA 2370 SKIN PANEL INSTALLATION
(SHEET 1 OF 5)
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### Page 53 (OCR)

BOEING SERVICE BULLETIN 777-53A0075
ALERT  ALERT
(2) 3
STA
2362.75
1018 D/3
10 LOCATIONS 4  12 LOCATIONS  1X2)4
- FWD
A-A  2384250
FIGURE 5: LEFT SIDE - STA 2370 SKIN PANEL INSTALLATION
(SHEET 2 OF 5)
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### Page 54 (OCR)

BOEING SERVICE BULLETIN 777-53A0075
ALERT  ALERT
_ GUSSET
- BRACKET  3 BRACKET
@ SPLICE PLATE
_________
SKIN
< EWD
B-B
ANGLE
BRACKET  CHORD,
FILLER  bOOSKIN
WD
TYPICAL
C-C
2384304
FIGURE 5: LEFT SIDE - STA 2370 SKIN PANEL INSTALLATION
(SHEET 3 OF 5)
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### 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 this figure.
More DataQtyIdentificationNameTaskStep
1148W2914-()ANGLE - FAIRING
ASSY, UPPER
Put/Hold1
1148W2917-9FILLER
1148W2917-11FILLER
1148W2917-7FILLER
1148W2912-1SKIN
1148W2912-3SKIN
Refer to the fastener table.14-HOLEDrill/Ream
1148W2914-()ANGLE - FAIRING
ASSY, UPPER
Re-
move/Keep
2
1148W2917-9FILLER
1148W2917-11FILLER
1148W2917-7FILLER
1148W2912-1SKIN
1148W2912-3SKIN
--HOLEDeburr
(a)1148W2917-9FILLERInstall
(Kept)
3
(a)1148W2917-11FILLER
(a)1148W2917-7FILLER
(a)1148W2918-3SPLICE PLATE
(a)1148W2920-1BRACKET
(a)1148W2914-()ANGLE - FAIRING
ASSY, UPPER
(a)1BACF3T03M14S8BFILLER
(a) Do not seal the exterior gap around
this skin panel.
1148W2912-1SKIN
(a) Do not seal the exterior gap around
this skin panel.
1148W2912-3SKIN
3-FASTENER
24-FASTENERInstall
(New)
4
FIGURE 5: LEFT SIDE - STA 2370 SKIN PANEL INSTALLATION
(SHEET 4 OF 5)
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ALERTALERT

### Page 56

More DataQtyIdentificationNameTaskStep
(a) Apply BMS 5-95, Class C to all mating surfaces. Refer to SOPM 20-50-19 as an accepted procedure.
The codes shown below agree with the letter shown in the upper left corner of the fastener symbols in the figure.
A number in the lower right corner gives the grip length of the fastener. The QTY numbers shown below are the
number of fasteners necessary for this figure.
More DataHole DiaQtyIdentificationNameCode
(a)0.2026 -
0.2036
2BACB30NW6K5XBOLT, 100 DEG HEX
DR
D
-2BACC30M6COLLAR
(a)0.2651 -
0.2661
7BACB30NW8K5XBOLT, 100 DEG HEX
DR
(a)0.2651 -
0.2661
1BACB30NW8K6XBOLT, 100 DEG HEX
DR
(a)0.2651 -
0.2661
4BACB30NW8K9XBOLT, 100 DEG HEX
DR
-12BACC30M8COLLAR
-3BACR15CE5KE5RIVET, 100 DEGH
-6BACR15CE5KE6RIVET, 100 DEG
-1BACR15CE5KE8RIVET, 100 DEG
(a) Install fasteners with BMS 5-95 sealant. Refer to SOPM 20-50-19, Method 2 as an accepted procedure.
FIGURE 5: LEFT SIDE - STA 2370 SKIN PANEL INSTALLATION
(SHEET 5 OF 5)
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ALERTALERT

### Page 57 (OCR)

BOEING SERVICE BULLETIN 777-53A0075
ALERT  ALERT
STA
2370
FWD  SPLICE PLATE
FILLER
123
FILLER
SKIN 1
123  BRACKET
12 3 SKIN  FILLER  ANGLE  2384354
FIGURE 6: RIGHT SIDE - STA 2370 SKIN PANEL INSTALLATION
(SHEET 1 OF 5)
Original Issue: January 14, 2015
PROPRIETARY - Copyright © Unpublished  Export Controlled ECCN: 9E991 - BOEING  777-53A0075
Work - See page 1 for details.  57 of 232

### Page 58 (OCR)

BOEING SERVICE BULLETIN 777-53A0075
ALERT  ALERT
STA  12 4
2370
STA
2362.75
DI&
• 10 LOCATIONS
12 LOCATIONS
FWD
A-A  2384355
FIGURE 6: RIGHT SIDE - STA 2370 SKIN PANEL INSTALLATION
(SHEET 2 OF 5)
Original Issue: January 14, 2015
Export Controlled ECCN: 9E991 - BOEING  PROPRIETARY - Copyright © Unpublished  777-53A0075
Work - See page 1 for details.  58 of 232

### Page 59 (OCR)

BOEING SERVICE BULLETIN 777-53A0075
ALERT  ALERT
GUSSET-
BRACKET 3  BRACKET -
SPLICE PLATE (3)
SKIN
FWD
B-B
ANGLE
_ CHORD  (2 3  BRACKET
FILLER 3
SKIN ĐO3
FWD
TYPICAL
C-C
2384365
FIGURE 6: RIGHT SIDE - STA 2370 SKIN PANEL INSTALLATION
(SHEET 3 OF 5)
Original Issue: January 14, 2015
PROPRIETARY - Copyright © Unpublished  Export Controlled ECCN: 9E991 - BOEING  777-53A0075
Work - See page 1 for details.  59 of 232

### Page 60

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 this figure.
More DataQtyIdentificationNameTaskStep
1148W2914-()ANGLE - FAIRING
ASSY, UPPER
Put/Hold1
1148W2917-9FILLER
1148W2917-11FILLER
1148W2917-7FILLER
1148W2912-2SKIN
1148W2912-4SKIN
Refer to the fastener table.14-HOLEDrill/Ream
1148W2914-()ANGLE - FAIRING
ASSY, UPPER
Re-
move/Keep
2
1148W2917-9FILLER
1148W2917-11FILLER
1148W2917-7FILLER
1148W2912-2SKIN
1148W2912-4SKIN
--HOLEDeburr
(a)1148W2917-9FILLERInstall
(Kept)
3
(a)1148W2917-11FILLER
(a)1148W2917-7FILLER
(a)1148W2918-4SPLICE PLATE
(a)1148W2920-2BRACKET
(a)1148W2914-()ANGLE - FAIRING
ASSY, UPPER
(a)1BACF3T03M14S8BFILLER
(a) Do not seal the exterior gap around
this skin panel.
1148W2912-2SKIN
(a) Do not seal the exterior gap around
this skin panel.
1148W2912-4SKIN
3-FASTENER
24-FASTENERInstall
(New)
4
FIGURE 6: RIGHT SIDE - STA 2370 SKIN PANEL INSTALLATION
(SHEET 4 OF 5)
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: January 14, 2015
777-53A0075
60 of 232
BOEING SERVICE BULLETIN 777-53A0075
ALERTALERT

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