# Boeing Alert Service Bulletin 747-54A2246: No revision named

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- Title as filed: SB-747-54A2246-00--
- Pages: 55
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### Page 1

Commercial 
Airplanes
747
Service Bulletin
ALERT
Number: 747-54A2246
Original Issue: February 05, 2016
ATA System: 5461
SUBJECT: NACELLES/PYLONS - No. 1 and No. 4 Engines Aft Strut Fairings - Vapor Seal, Block
Seal, and Heat Shield Seal Inspection and 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 © 2016 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Unpublished Work.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: February 05, 2016
747-54A2246
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3.0

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PROPRIETARY - Copyright © Unpublished
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Original Issue: February 05, 2016
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ALERTALERT
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Table of Contents
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1. PLANNING INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
A. Effectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1. Airplanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
B. Concurrent Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
C. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
E. Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
H. Weight and Balance Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
1. Existing Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2. Data Supplied with this Service Bulletin: . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3. Installation Drawings Used in the Preparation of this Service Bulletin: . . . . . . . . . . . 18
K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
M. Software Accomplishment Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2. MATERIAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
A. Material - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
C. Parts Necessary for Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
1. Kits/Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2. Parts and Materials Supplied by the Operator . . . . . . . . . . . . . . . . . . . . . . . . 21
3. Parts Modified and Reidentified . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
4. Parts Removed and Not Replaced . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
D. Parts Necessary to Change Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
E. Special Tooling - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
F. Special Tooling Necessary to do this Service Bulletin . . . . . . . . . . . . . . . . . . . . . . . 22
3. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
B. WORK INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
FIGURE 1: NO. 1 STRUT - VAPOR SEAL DETAILED INSPECTION . . . . . . . . . . . . . . . . . . 29
FIGURE 2: NO. 4 STRUT - VAPOR SEAL DETAILED INSPECTION . . . . . . . . . . . . . . . . . . 32
FIGURE 3: NO. 1 STRUT - VAPOR SEAL, BLOCK SEAL, AND HEAT SHIELD SEAL - REMOVAL . 35
FIGURE 4: NO. 4 STRUT - VAPOR SEAL, BLOCK SEAL, AND HEAT SHIELD SEAL - REMOVAL . 37
FIGURE 5: NO. 1 STRUT - STRUCTURAL INSPECTION FOR HEAT DAMAGE - DETAILED INSPECTION
AND EDDY CURRENT CONDUCTIVITY MEASUREMENT . . . . . . . . . . . . . . . . . 39
FIGURE 6: NO. 4 STRUT - STRUCTURAL INSPECTION FOR HEAT DAMAGE - DETAILED INSPECTION
AND EDDY CURRENT CONDUCTIVITY MEASUREMENT . . . . . . . . . . . . . . . . . 42
FIGURE 7: NO. 1 STRUT - VAPOR SEAL, BLOCK SEAL, AND HEAT SHIELD SEAL - INSTALLATION
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
FIGURE 8: NO. 4 STRUT - VAPOR SEAL, BLOCK SEAL, AND HEAT SHIELD SEAL - INSTALLATION
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
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Original Issue: February 05, 2016
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APPENDIX A: LOGIC DIAGRAM FOR PARAGRAPH 1.E. COMPLIANCE: TABLE 1: NO. 1 AND NO. 4 STRUT
AFT FAIRING - SAFETY RELATED - INITIAL AND REPEAT VAPOR SEAL INSPECTIONS
AND SEAL REPLACEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
APPENDIX B: PART DEMAND INTENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Export Controlled ECCN: 9E991 - BOEING
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Commercial 
Airplanes
747
Service Bulletin
ALERT
SummaryNumber: 747-54A2246Original Issue: February 05, 2016
ATA System: 5461
SUBJECT: NACELLES/PYLONS - No. 1 and No. 4 Engines Aft Strut Fairings - Vapor Seal, Block
Seal, and Heat Shield Seal Inspection and Replacement
THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH
1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO
THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO
THE NEW OWNER.
CONCURRENT REQUIREMENTS
None.
BACKGROUND
Accomplishment of this service bulletin will detect heat damage on the vapor seal between the strut and aft
fairing. If any heat damaged seals are not found and replaced, in the event of flammable fluid leakage in the aft
fairing, this could lead to an uncontained engine strut fire.
Boeing has received reports from operators of damaged vapor seals, block seals, and heat shield seals on
number 1 and number 4 engines aft strut fairings. These reports from the operators show vapor seal damage
on the outboard pylons occurring at 1468 flight cycles and fully compromised vapor seals at 2768 flight cycles
and 3626 flight cycles.
The aft fairing vapor seals, block seals, and heat shield seals prevent hot exhaust gases from entering the aft
fairing. Boeing analysis has found that hot exhaust gases leaking past the heat shield seal can cause heat
damage to the block seals and vapor seals. Boeing has determined that this issue only affects outboard pylons
because in these pylons the vapor seal is located directly above the heat shield seal. If the vapor seal has heat
damage, and if there is a hydraulic leak that sprays onto the strut bulkhead, fluid could drain across the worn
seal and contact heat shield surfaces below the seals. The heat shield could then ignite the fluid and the fire
could extend to the aft fairing. In addition, Boeing has determined that extended operation of the airplane with
degraded seals can likely cause heat damage to secondary structure and structure within the strut and aft fairing.
This service bulletin gives instructions to inspect for heat damage on the vapor seals between the strut and aft
fairing. If the vapor seal is found with any heat damage, this service bulletin gives instructions to replace vapor
seals, block seals, and heat shield seals to reduce risk of potential fire due to a heat damaged vapor seal. Boeing
has determined that inspection and replacement of the seals are safety related.
In addition, this service bulletin gives inspection and repair instructions for heat damage on adjacent structure
of the seals. Boeing has determined that the inspection and repair of the structure are economic related. Boeing
recommends to do the inspection and repair of the adjacent structure during the seal replacement, before
installation of new seals, to prevent possible operational disruptions.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: February 05, 2016
747-54A2246
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### Page 6

A future service bulletin will be released to give instructions to install new and improved parts including block
seals, and heat shield seals. The accomplishment of the future service bulletin will be terminating action for the
inspection requirements, both safety and economic related, given in this service bulletin.
Boeing Service Related Problem (SRP) 747-8-SRP-54-0153 is related to this service bulletin.
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., Compliance and Paragraph
1.F., Approval
YesAD Related
Paragraph 1.H., Weight and Balance ChangesNoWeight and Balance Change
Paragraph 1.I., Electrical Load DataNoElectrical Load Changed
Paragraph 1.K., Publications AffectedNoPublications 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/PartsNoKits/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
SAFETY RELATED - INITIAL AND REPEAT INSPECTIONS AND REPLACEMENT OF SEALS
1. Get access between the strut and aft fairing on Engine No. 1 and Engine No. 4.
2. Do a detailed inspection of the vapor seal for heat damage.
a. If no heat damage is found on the vapor seals, repeat the detailed inspection of the vapor seal for
heat damage at the time given in the service bulletin.
b. If any heat damage is found on the vapor seals, remove the aft fairing. Replace the vapor seals,
block seals, and heat shield seals and repeat the detailed inspection of the vapor seal for heat
damage at the time given in the service bulletin.
NOTE: Boeing recommends to do a detailed inspection and eddy current conductivity
measurement of the specified structure for heat damage and do the necessary repairs
during the seal replacement, before installation of new seals. This is given as an economic
consideration to prevent possible operational disruptions. Refer to ECONOMIC RELATED
- STRUCTURAL INSPECTION AND REPAIR FOR HEAT DAMAGE.
3. Put the airplane back to a serviceable condition.
Export Controlled ECCN: 9E991 - BOEING
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Work - See page 1 for details.
Original Issue: February 05, 2016
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ECONOMIC RELATED - STRUCTURAL INSPECTION AND REPAIR FOR HEAT DAMAGE
1. Remove and keep the aft strut fairing on Engine No. 1 and Engine No. 4.
2. Do a detailed inspection and eddy current conductivity measurement of the specified structure for heat
damage and do the necessary repairs.
NOTE: Boeing recommends to do a detailed inspection and eddy current conductivity measurement
of the specified structure for heat damage and do the necessary repairs during the seal
replacement, before installation of new seals. This is given as an economic consideration to
prevent possible operational disruptions.
3. Install kept aft strut fairing on Engine No. 1 and Engine No. 4.
4. Put the airplane back to a serviceable condition.
A future service bulletin will be released to give instructions to install new and improved parts including block
seals, and heat shield seals. The accomplishment of the future service bulletin will be terminating action for the
inspections, both safety and economic related, given in this service bulletin.
EFFECTIVITY
All 747-8 and 747-8F Airplane(s). 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, that are safety related, given in
this service bulletin mandatory.
Refer to Paragraph 1.E., Compliance.
INDUSTRY SUPPORT INFORMATION
Boeing warranty remedies are available for airplanes in warranty as of February 12, 2015. 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
Table 1: SAFETY RELATED - INITIAL AND REPEAT VAPOR SEAL INSPECTIONS
Elapsed HoursTotal Task HoursAirplanes
3.403.40All Airplanes
Table 2: SAFETY RELATED - SEAL REPLACEMENT
Elapsed HoursTotal Task HoursAirplanes
19.8131.8All Airplanes
Export Controlled ECCN: 9E991 - BOEING
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Table 3: ECONOMIC RELATED - STRUCTURAL INSPECTION AND REPAIR FOR
HEAT DAMAGE
Elapsed HoursTotal Task HoursAirplanes
17.2129.2All Airplanes (a)
(a) Estimated Task Hours includes detailed inspection
only. This estimate does not include the task time to
do the High Frequency Eddy Current (HFEC) conduc-
tivity measurement.
Refer to Paragraph 1.G., Manpower.
MATERIAL INFORMATION
Operator Supplied Parts/Materials.
Refer to Paragraph 2.A., Material - Price and Availability.
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### Page 9 (OCR)

BOEING SERVICE BULLETIN 747-54A2246
ALERT  ALERT
SAFETY RELATED:
DO A DETAILED INSPECTION OF THE VAPOR SEALS
FOR HEAT DAMAGE. IF NO HEAT DAMAGE IS FOUND,
REPEAT THE DETAILED INSPECTION AT THE TIME
GIVEN IN THE SERVICE BULLETIN. IF ANY HEAT
DAMAGE IS FOUND, REPLACE THE VAPOR SEALS,
BLOCK SEALS. AND HEAT SHIELD SEALS AND
REPEAT THE DETAILED INSPECTION OF THE VAPOR
SEAL AT THE TIME GIVEN IN THE SERVICE BULLETIN.
ECONOMIC RELATED:
DO A DETAILED INSPECTION AND EDDY
CURRENT CONDUCTIVITY MEASUREMENT OF
THE SPECIFIED STRUCTURE FOR HEAT
DAMAGE AND DO THE NECESSARY REPAIRS.
NO. 1 AND NO. 4 STRUT AFT FAIRING
2461791
Original Issue: February 05, 2016
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Export Controlled ECCN: 9E991 - BOEING
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ALERTALERT
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### Page 11

Commercial 
Airplanes
747
Service Bulletin
ALERT
Number: 747-54A2246
Original Issue: February 05, 2016
ATA System: 5461
SUBJECT: NACELLES/PYLONS - No. 1 and No. 4 Engines Aft Strut Fairings - Vapor Seal, Block
Seal, and Heat Shield Seal Inspection and Replacement
THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH
1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO
THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO
THE NEW OWNER.
1.    PLANNING INFORMATION
A. Effectivity
1. Airplanes
This service bulletin is applicable to all 747-8 and 747-8F Airplanes line numbers 1420 and on in
1 Group. The Variable Numbers and Group Information for the applicable airplanes is given below.
Refer to Service Bulletin Index D6-30300 Part 3 for Airplane Variable Number, Line Number, and
Serial Number data.
NOTE: The Variable Number table below includes all affected airplanes up to Line Number 1539.
Affected airplanes after Line Number 1539 will be added to the service bulletin's
MyBoeingFleet.com (MBF) "get effectivity" result when they are added to the MBF Fleet
Profile Page.
DESCRIPTIONCONFIGURATIONGROUP
All 747-8 and 747-8F Airplanes line numbers 1420 and on.-1
Airplane Models:
747-8, 747-8F
GroupVariable Number
1RC001 - RC009
1RC021 - RC040
1RC051 - RC060
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### Page 12

GroupVariable Number
1RC066 - RC072
1RC076 - RC077
1RC501 - RC514
1RC521 - RC528
1RC541
1RC546 - RC566
1RC571 - RC582
1RC601 - RC605
1RC641 - RC644
1RC651 - RC652
1RC661
1RC671 - RC674
2. Spares Affected
None.
B. Concurrent Requirements
None.
C. Reason
Accomplishment of this service bulletin will detect heat damage on the vapor seal between the strut
and aft fairing. If any heat damaged seals are not found and replaced, in the event of flammable fluid
leakage in the aft fairing, this could lead to an uncontained engine strut fire.
Boeing has received reports from operators of damaged vapor seals, block seals, and heat shield seals
on number 1 and number 4 engines aft strut fairings. These reports from the operators show vapor
seal damage on the outboard pylons occurring at 1468 flight cycles and fully compromised vapor seals
at 2768 flight cycles and 3626 flight cycles.
The aft fairing vapor seals, block seals, and heat shield seals prevent hot exhaust gases from entering
the aft fairing. Boeing analysis has found that hot exhaust gases leaking past the heat shield seal can
cause heat damage to the block seals and vapor seals. Boeing has determined that this issue only
affects outboard pylons because in these pylons the vapor seal is located directly above the heat shield
seal. If the vapor seal has heat damage, and if there is a hydraulic leak that sprays onto the strut
bulkhead, fluid could drain across the worn seal and contact heat shield surfaces below the seals. The
heat shield could then ignite the fluid and the fire could extend to the aft fairing. In addition, Boeing has
determined that extended operation of the airplane with degraded seals can likely cause heat damage
to secondary structure and structure within the strut and aft fairing.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: February 05, 2016
747-54A2246
12 of 55
BOEING SERVICE BULLETIN 747-54A2246
ALERTALERT

### Page 13

This service bulletin gives instructions to inspect for heat damage on the vapor seals between the strut
and aft fairing. If the vapor seal is found with any heat damage, this service bulletin gives instructions
to replace vapor seals, block seals, and heat shield seals to reduce risk of potential fire due to a heat
damaged vapor seal. Boeing has determined that inspection and replacement of the seals are safety
related.
In addition, this service bulletin gives inspection and repair instructions for heat damage on adjacent
structure of the seals. Boeing has determined that the inspection and repair of the structure are economic
related. Boeing recommends to do the inspection and repair of the adjacent structure during the seal
replacement, before installation of new seals, to prevent possible operational disruptions.
A future service bulletin will be released to give instructions to install new and improved parts including
block seals, and heat shield seals. The accomplishment of the future service bulletin will be terminating
action for the repeat inspection requirements, both safety and economic related given in this service
bulletin.
Boeing Service Related Problem (SRP) 747-8-SRP-54-0153 is related to this service bulletin.
D. Description
SAFETY RELATED - INITIAL AND REPEAT INSPECTIONS AND REPLACEMENT OF SEALS
1. Get access between the strut and aft fairing on Engine No. 1 and Engine No. 4.
2. Do a detailed inspection of the vapor seal for heat damage.
a. If no heat damage is found on the vapor seals, repeat the detailed inspection of the vapor
seal for heat damage at the time given in the service bulletin.
b. If any heat damage is found on the vapor seals, remove the aft fairing. Replace the vapor
seals, block seals, and heat shield seals and repeat the detailed inspection of the vapor seal
for heat damage at the time given in the service bulletin.
NOTE: Boeing recommends to do a detailed inspection and eddy current conductivity
measurement of the specified structure for heat damage and do the necessary repairs
during the seal replacement, before installation of new seals. This is given as an
economic consideration to prevent possible operational disruptions. Refer to
ECONOMIC RELATED - STRUCTURAL INSPECTION AND REPAIR FOR HEAT
DAMAGE.
3. Put the airplane back to a serviceable condition.
ECONOMIC RELATED - STRUCTURAL INSPECTION AND REPAIR FOR HEAT DAMAGE
1. Remove and keep the aft strut fairing on Engine No. 1 and Engine No. 4.
2. Do a detailed inspection and eddy current conductivity measurement of the specified structure for
heat damage and do the necessary repairs.
NOTE: Boeing recommends to do a detailed inspection and eddy current conductivity
measurement of the specified structure for heat damage and do the necessary repairs
during the seal replacement, before installation of new seals. This is given as an economic
consideration to prevent possible operational disruptions.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: February 05, 2016
747-54A2246
13 of 55
BOEING SERVICE BULLETIN 747-54A2246
ALERTALERT

### Page 14

3. Install kept aft strut fairing on Engine No. 1 and Engine No. 4.
4. Put the airplane back to a serviceable condition.
A future service bulletin will be released to give instructions to install new and improved parts including
block seals, and heat shield seals. The accomplishment of the future service bulletin will be terminating
action for the repeat inspections, both safety and economic related, given in this service bulletin.
The work in this service bulletin is done in the maintenance zone(s) given below.
Affected Maintenance Zones
ZoneModel
452, 454, 482, 484747-8, 747-8F
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, that are
safety related, given in this service bulletin mandatory.
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.
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
A.
The Conditions, Actions and Compliance times shown apply to each strut independently.
Safety Related and Economic Related Compliance Information
1. For safety related compliance information, see the table below:
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Table 1: No. 1 and No. 4 Strut Aft Fairing - Safety Related - Initial and Repeat Vapor Seal In-
spections and Seal Replacement
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
-Within 6
months after
the original is-
sue date of this
service bul-
letin. (a)
Before 1,800
total flight cy-
cles or within
1,800 flight cy-
cles after vapor
seal, block
seals, and heat
shield seal re-
placement,
whichever oc-
curs later. (a)
(b)
Do PART 2: VAPOR
SEAL DETAILED IN-
SPECTION (SAFETY
RELATED) for heat
damage. (a)
All airplanes
1,200 flight cycles-Repeat PART 2: VA-
POR SEAL DETAILED
INSPECTION (SAFETY
RELATED) for heat
damage.
CONDITION 1: NO
HEAT DAMAGE
FOUND (VAPOR
SEAL)
-Before further flightACTION 1: Do PART 3:
SEAL REPLACEMENT
(SAFETY RELATED).
(c)
CONDITION 2: ANY
HEAT DAMAGE
FOUND (VAPOR
SEAL)
1,200 flight cycles
(d)
Within 1,800 flight cycles after
the accomplishment of PART 3:
SEAL REPLACEMENT (SAFE-
TY RELATED). (d)
ACTION 2: Repeat
PART 2: VAPOR SEAL
DETAILED INSPEC-
TION (SAFETY RELAT-
ED) for heat damage.
(d)
(a) Previous accomplishment of a detailed inspection of the visible surfaces of the vapor seal
from inside and outside the strut and aft fairing for heat damage, a minimum of 10 inches from
the bottom of the seal as shown in FIGURE 1 and FIGURE 2, meets the requirements of the
detailed inspection of PART 2: VAPOR SEAL DETAILED INSPECTION (SAFETY RELATED).
Refer to 747-FTD-54-15002 for additional information related to this service bulletin issue.
(b) If the vapor seal (323U8452-3, QTY 1), block seals (323U8452-2, QTY 2), and heat shield
seal (323U8852-1, QTY 1) were all previously replaced at the same time for an aft fairing, the
compliance time is based on the number of flight cycles from when all three seals were replaced
on that aft fairing.
(c) Boeing recommends accomplishment of PART 4: STRUCTURAL INSPECTION AND REPAIR
FOR HEAT DAMAGE (ECONOMIC RELATED) during PART 3: SEAL REPLACEMENT
(SAFETY RELATED), before installation of new seals. PART 4 is given as an economic
consideration to prevent possible operational disruptions.
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Table 1: No. 1 and No. 4 Strut Aft Fairing - Safety Related - Initial and Repeat Vapor Seal In-
spections and Seal Replacement
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
(d) After the accomplishment of PART 3: SEAL REPLACEMENT (SAFETY RELATED), PART
2: VAPOR SEAL DETAILED INSPECTION (SAFETY RELATED) is accomplished within 1,800
flight cycles. Thereafter, PART 2: VAPOR SEAL DETAILED INSPECTION (SAFETY RELATED)
is repeated within 1,200 flight cycle intervals.
2. For economic related compliance information:
No compliance time is given.
Boeing recommends accomplishment of PART 4: STRUCTURAL INSPECTION AND REPAIR
FOR HEAT DAMAGE (ECONOMIC RELATED) during PART 3: SEAL REPLACEMENT (SAFETY
RELATED), before installation of new seals. PART 4 is given as an economic consideration to
prevent possible operational disruptions.
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 tables below show an estimate of the task hours necessary to do this inspection and replacement
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: SAFETY RELATED - INITIAL AND REPEAT VAPOR SEAL INSPECTIONS
Elapsed HoursTask HoursNumber of PersonsTask
1.401.401Open Access
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Table 1: SAFETY RELATED - INITIAL AND REPEAT VAPOR SEAL INSPECTIONS
Elapsed HoursTask HoursNumber of PersonsTask
0.300.301FIGURE 1
0.300.301FIGURE 2
1.401.401Close Access
3.403.40TOTAL FOR EACH AIRPLANE
Table 2: SAFETY RELATED - SEAL REPLACEMENT
Elapsed HoursTask HoursNumber of PersonsTask
8.0064.08Open Access
0.500.501FIGURE 3
0.500.501FIGURE 4
1.401.401FIGURE 7
1.401.401FIGURE 8
8.0064.08Close Access
19.8131.8TOTAL FOR EACH AIRPLANE
Table 3: ECONOMIC RELATED - STRUCTURAL INSPECTION AND REPAIR FOR HEAT
DAMAGE
Elapsed HoursTask HoursNumber of PersonsTask
8.0064.08Open Access
0.600.601FIGURE 5 (a)
0.600.601FIGURE 6 (a)
8.0064.08Close Access
17.2129.2TOTAL FOR EACH AIRPLANE
(a) Estimated Task Hours includes detailed inspection only. This estimate does
not include the task time to do the High Frequency Eddy Current (HFEC)
conductivity measurement.
H. Weight and Balance Changes
None.
I. Electrical Load Data
Not changed.
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J. References
1. Existing Data:
a. Boeing Service Letter 747-SL-51-048
b. Boeing Service Related Problem (SRP) 747-8-SRP-54-0153
c. Component Maintenance Manual (CMM) 54-00-01, 54-52-06
d. Service Bulletin Index D6-30300
e. Standard Overhaul Practices Manual (SOPM) 20-30-03, 20-50-01, 20-50-12, 20-50-19
f. 747 Non-Destructive Testing (NDT) Manual Part 6, 51-00-00
g. 747-8 Aircraft Maintenance Manual (AMM) 06-09-09, 27-51-00, 54-61-02, 54-62-03
h. 747-8F Structural Repair Manual (SRM) 54-50-02, 54-50-71
i. 747-8P Structural Repair Manual (SRM) 54-50-02, 54-50-71
2. Data Supplied with this Service Bulletin:
None.
3. Installation Drawings Used in the Preparation of this Service Bulletin:
TitleDrawing Number
FWD HEATSHIELD INSTL - OUTBD AFT FAIRING323U8801
SEAL INSTALLATION - OUTBD AFT FAIRING323U8450
AFT FAIRING INSTL - OUTBD323U8300
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:
None.
2. Damage Tolerance Based Structural Inspections:
Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue
Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the
Maintenance Program. This service bulletin does not affect FCS, therefore DTIs are not necessary.
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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
The operator can supply the parts and materials shown in Paragraph 2.C., Parts Necessary for Each
Airplane. As an alternative, operators can purchase the parts from Boeing Spares. This service bulletin
does not show the Boeing price and supply data.
Operators are encouraged to complete the survey provided in APPENDIX B 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 available for 747 airplanes in warranty as of February 12, 2015. For
task hour and material reimbursement for airplanes in warranty as of that date, send a warranty claim
to Boeing Fleet Support Contracts - Warranty. 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
None.
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
This part is only necessary
if any heat damage is found
on the vapor seal.
VAPOR SEAL2323U8452-3
This part is only necessary
if any heat damage is found
on the vapor seal.
BLOCK SEAL4323U8452-2
This part is only necessary
if any heat damage is found
on the vapor seal.
HEAT SHIELD SEAL2323U8852-1
(a)DIAGONAL BRACE - LUG2321U8730-1
(a)FITTING - UPPER LATERAL RE-
STRAINT
2321U8591-3 or
321U8591-6
(b)FIREWALL SEALANT4 oz.BMS 5-63
(c)ADHESIVE4 oz.SOPM 20-50-12,
TYPE 60
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NotesNameQTYPart Number /
Specification
(a) This part is only necessary if any heat damage is found on the installed part and it does
not meet the specified International Annealed Copper Standards (IACS) values.
(b) Refer to the Qualified Products List at the end of the Boeing Material Specification (BMS)
for supplier data.
(c) Refer to the Boeing Standard Overhaul Practices Manual (SOPM) for material information
and 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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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 747 Structural Repair Manual,
Chapter 51.
— Values for airframe maintenance tasks are included in Chapter 20 of 747
Aircraft Maintenance Manual (AMM).
— Values for engine maintenance tasks are included in Chapter 70 of 747
Aircraft 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. 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.
6. A Detailed Inspection 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.
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7. 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.
8. Boeing Service Letter 747-SL-51-048, 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.
9. Refer to APPENDIX A 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. Refer to APPENDIX B for Boeing Part Demand Intent.
11. If it is necessary to remove more parts for access, you can remove those parts. If
you can get access without removing identified parts, it is not necessary to remove
all of the identified parts. Jacking and shoring limitations must be observed.
12. 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.
13. Use of colors in Figures is based on guidance from the ATA e-Business Program
(ATA) iSpec 2200.
14. 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.
15. The compliance times for the actions in Paragraph 3.B., WORK INSTRUCTIONS
are in Paragraph 1.E., Compliance.
16. 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. 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.
17. The instructions in Paragraph 3.B., Work Instructions, are applicable to No. 1 and
No. 4 struts. Accomplishment of the work instructions on each strut can be done
independently.
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B. WORK INSTRUCTIONS
SAFETY RELATED - INITIAL AND REPEAT VAPOR SEAL INSPECTION
1. Do PART 1: OPEN ACCESS for the Vapor Seal Inspections.
2. RC - Do PART 2: VAPOR SEAL DETAILED INSPECTION (SAFETY RELATED) for heat damage.
a. CONDITION 1: NO HEAT DAMAGE FOUND (VAPOR SEAL).
(1) Repeat PART 2: VAPOR SEAL DETAILED INSPECTION (SAFETY RELATED) for heat
damage.
b. CONDITION 2: ANY HEAT DAMAGE FOUND (VAPOR SEAL).
(1) ACTION 1: Do PART 3: SEAL REPLACEMENT (SAFETY RELATED). Go to SAFETY
RELATED - SEAL REPLACEMENT.
NOTE: Boeing recommends accomplishment of PART 4: STRUCTURAL INSPECTION
AND REPAIR FOR HEAT DAMAGE (ECONOMIC RELATED) during PART 3:
SEAL REPLACEMENT (SAFETY RELATED), before installation of new seals.
PART 4 is given as an economic consideration to prevent possible operational
disruptions. Refer to ECONOMIC RELATED - STRUCTURAL INSPECTION
AND REPAIR FOR HEAT DAMAGE.
(2) ACTION 2: Repeat PART 2: VAPOR SEAL DETAILED INSPECTION (SAFETY RELATED)
for heat damage.
3. Do PART 5: CLOSE ACCESS for the Vapor Seal Inspections.
4. Put the airplane back to a serviceable condition.
SAFETY RELATED - SEAL REPLACEMENT
1. Do PART 1: OPEN ACCESS.
2. RC - Do PART 3: SEAL REPLACEMENT (SAFETY RELATED)
3. Do PART 5: CLOSE ACCESS.
4. Put the airplane back to a serviceable condition.
ECONOMIC RELATED - STRUCTURAL INSPECTION AND REPAIR FOR HEAT DAMAGE
1. Do PART 1: OPEN ACCESS.
2. Do PART 4: STRUCTURAL INSPECTION AND REPAIR FOR HEAT DAMAGE (ECONOMIC
RELATED).
NOTE: Boeing recommends accomplishment of PART 4: STRUCTURAL INSPECTION AND
REPAIR FOR HEAT DAMAGE (ECONOMIC RELATED) during PART 3: SEAL
REPLACEMENT (SAFETY RELATED), before installation of new seals. PART 4 is given
as an economic consideration to prevent possible operational disruptions.
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3. Do PART 5: CLOSE ACCESS.
4. Put the airplane back to a serviceable condition.
PART 1: OPEN ACCESS
1. For the Vapor Seal Inspections, do the following:
a. Deactivate the trailing edge flaps. Refer to 747-8 AMM 27-51-00 as an accepted procedure.
b. Open the access doors shown in the table below. Refer to 747-8 AMM 06-09-09 for the location
of these doors. Refer to 747-8 AMM 54-62-03 as an accepted procedure.
No. 4 StrutNo. 1 Strut
OutboardInboardInboardOutboard
484AR484AL454AR454AL
481KR481KL451KR451KL
2. For Seal Replacement and Structural Inspection and Repair for Heat Damage, do the following:
a. Deactivate the trailing edge flaps. Refer to 747-8 AMM 27-51-00 as an accepted procedure.
b. Remove and keep aft fairing. Refer to 747-8 AMM 54-61-02 as an accepted procedure.
PART 2: VAPOR SEAL DETAILED INSPECTION (SAFETY RELATED)
1. Do a detailed inspection of the vapor seals for heat damage in accordance with the figures in the
following table.
Heat damage is defined as, but not limited to, any hole(s), tear(s), break(s), or missing piece(s)
from visible areas of the vapor seals that does not maintain structural integrity of the seal. Surface
damage, such as minor cracking or discoloration on an intact seal is not considered heat damage.
No. 4 StrutNo. 1 Strut
FIGURE 2FIGURE 1
PART 3: SEAL REPLACEMENT (SAFETY RELATED)
1. Remove the aft fairing vapor seal, heat shield seal, and block seals in accordance with the figures
in the following table.
No. 4 StrutNo. 1 Strut
FIGURE 4FIGURE 3
2. Install the new aft fairing vapor seal, heat shield seal, and block seals in accordance with the
figures in the following table:
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No. 4 StrutNo. 1 Strut
FIGURE 8FIGURE 7
PART 4: STRUCTURAL INSPECTION AND REPAIR FOR HEAT DAMAGE (ECONOMIC RELATED)
1. Remove and keep the vapor seal retainers from AFT FAIRING - FRAME 1 on No. 1 and No. 4
strut aft fairings. Refer to CMM 54-52-06, Repair 2-1, as an accepted procedure.
2. Do a detailed inspection of the specified strut and aft fairing structure for discoloration due to heat
damage in accordance with the figures in the following table. Also, do an eddy current conductivity
measurement in accordance with 747 NDT Manual Part 6, 51-00-00, Procedure 3 for International
Annealed Copper Standards (IACS) values on the discolored areas of the specified strut and aft
fairing structure in accordance with the figures in the following table.
No. 4 StrutNo. 1 Strut
FIGURE 6FIGURE 5
Do the action according to the applicable condition below for each inspected part in the strut and
aft fairing structure:
a. CONDITION 3: NO DISCOLORATION DUE TO HEAT DAMAGE FOUND
(1) No more inspection or repair action is necessary on that part.
b. CONDITION 4: ANY DISCOLORATION DUE TO HEAT DAMAGE FOUND AND MEASURED
IACS VALUE IS WITHIN ACCEPTABLE RANGE
(1) No more inspection or repair action is necessary on that part.
c. CONDITION 5: ANY DISCOLORATION DUE TO HEAT DAMAGE FOUND AND MEASURED
IACS VALUE IS OUTSIDE OF ACCEPTABLE RANGE
(1) For DIAGONAL BRACE - LUG, and FITTING - UPPER LATERAL RESTRAINT:
Replace the heat damaged part or contact The Boeing Company for alternative repair
instructions and do the repair. Refer to 747-8P SRM 54-50-02, 747-8F SRM 54-50-02,
or CMM 54-00-01 for part replacement information on the strut. Refer to 747-8P SRM
54-50-71, 747-8F SRM 54-50-71, or CMM 54-52-06 for part replacement information in
the aft fairing.
(2) For AFT STRUT BULKHEAD, FITTING ASSY - DIAGONAL BRACE - LUG, and AFT
FAIRING FRAME 1 ASSY:
Contact The Boeing Company for repair instructions and do the repair.
3. Install the kept vapor seal retainers on AFT FAIRING - FRAME 1 on No. 1 and No. 4 strut aft
fairings. Refer to CMM 54-52-06, Repair 2-1, as an accepted procedure.
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PART 5: CLOSE ACCESS
1. For the Vapor Seal Surface Inspections, do the following:
a. Close the access doors shown in the table below. Refer to 747-8 AMM 06-09-09 for the location
of these doors. Refer to 747-8 AMM 54-62-03 as an accepted procedure.
No. 4 StrutNo. 1 Strut
OutboardInboardInboardOutboard
484AR484AL454AR454AL
481KR481KL451KR451KL
b. Activate the trailing edge flaps. Refer to 747-8 AMM 27-51-00 as an accepted procedure.
2. For Seal Replacement and Structural Inspection and Repair for Heat Damage, do the following:
a. Install kept aft fairing. Refer to 747-8 AMM 54-61-02 as an accepted procedure.
b. Activate the trailing edge flaps. Refer to 747-8 AMM 27-51-00 as an accepted procedure.
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### Page 29 (OCR)

BOEING SERVICE BULLETIN 747-54A2246
ALERT  ALERT
VAPOR SEAL
NO. 1 STRUT AFT FAIRING
2461815
FIGURE 1: NO. 1 STRUT - VAPOR SEAL DETAILED INSPECTION
(SHEET 1 OF 3)
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### Page 30 (OCR)

BOEING SERVICE BULLETIN 747-54A2246
ALERT  ALERT
VAPOR SEAL
10.00
MINIMUM
INSPECTION AREA
A-A
2461826
FIGURE 1: NO. 1 STRUT - VAPOR SEAL DETAILED INSPECTION
(SHEET 2 OF 3)
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### Page 31

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 detailed inspec-
tion of the vapor seal
in the specified area
for heat damage. (a)
(b)
1323U8452-3VAPOR SEALInspect1
(a) Do a detailed inspection of the visible surfaces of the vapor seal from inside and outside the strut and aft
fairing. Inspection of the contact surfaces of the seal with strut and aft fairing is not necessary.
(b) Heat damage is defined as, but not limited to, any hole(s), tear(s), break(s), or missing piece(s) from vis-
ible areas of the vapor seals that does not maintain structural integrity of the seal. Surface damage, such
as minor cracking or discoloration on an intact seal is not considered heat damage.
FIGURE 1: NO. 1 STRUT - VAPOR SEAL DETAILED INSPECTION
(SHEET 3 OF 3)
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BOEING SERVICE BULLETIN 747-54A2246
ALERTALERT

### Page 32 (OCR)

BOEING SERVICE BULLETIN 747-54A2246
ALERT  ALERT
VAPOR SEAL
NO. 4 STRUT AFT FAIRING
2461816
FIGURE 2: NO. 4 STRUT - VAPOR SEAL DETAILED INSPECTION
(SHEET 1 OF 3)
Original Issue: February 05, 2016
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### Page 33 (OCR)

BOEING SERVICE BULLETIN 747-54A2246
ALERT  ALERT
VAPOR SEAL C
10.00
MINIMUM
I INSPECTION AREA
A-A
2461827
FIGURE 2: NO. 4 STRUT - VAPOR SEAL DETAILED INSPECTION
(SHEET 2 OF 3)
Original Issue: February 05, 2016
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### Page 34

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 detailed inspec-
tion of the vapor seal
in the specified area
for heat damage. (a)
(b)
1323U8452-3VAPOR SEALInspect1
(a) Do a detailed inspection of the visible surfaces of the vapor seal from inside and outside the strut and aft
fairing. Inspection of the contact surfaces of the seal with strut and aft fairing is not necessary.
(b) Heat damage is defined as, but not limited to, any hole(s), tear(s), break(s), or missing piece(s) from vis-
ible areas of the vapor seals that does not maintain structural integrity of the seal. Surface damage, such
as minor cracking or discoloration on an intact seal is not considered heat damage.
FIGURE 2: NO. 4 STRUT - VAPOR SEAL DETAILED INSPECTION
(SHEET 3 OF 3)
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BOEING SERVICE BULLETIN 747-54A2246
ALERTALERT

### Page 35 (OCR)

BOEING SERVICE BULLETIN 747-54A2246
ALERT  ALERT
VAPOR SEAL
HEATSHIELD SEAL
2 BLOCK SEA
(2 LOCATIONS
SEAL RETAINER
NO. 1 STRUT AFT FAIRING
2461799
FIGURE 3: NO. 1 STRUT - VAPOR SEAL, BLOCK SEAL, AND HEAT SHIELD SEAL - REMOVAL
(SHEET 1 OF 2)
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### Page 36

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
Refer to CMM 54-
52-06, Repair 2-1,
as an accepted pro-
cedure.
1323U8452-3VAPOR SEALRemove1
Refer to CMM 54-
52-06, Repair 2-1,
as an accepted pro-
cedure.
2323U8452-2BLOCK SEALRemove2
Bolts and washers.2-FASTENERRemove / Keep3
1-SEAL RETAINERRemove / Keep
1323U8852-1HEAT SHIELD SEALRemove
FIGURE 3: NO. 1 STRUT - VAPOR SEAL, BLOCK SEAL, AND HEAT SHIELD SEAL - REMOVAL
(SHEET 2 OF 2)
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BOEING SERVICE BULLETIN 747-54A2246
ALERTALERT

### Page 37 (OCR)

BOEING SERVICE BULLETIN 747-54A2246
ALERT  ALERT
VAPOR SEAL
HEATSHIELD SEAL
A LOCATIONS)
SEAL RETAINER
NO. 4 STRUT AFT FAIRING
2461822
FIGURE 4: NO. 4 STRUT - VAPOR SEAL, BLOCK SEAL, AND HEAT SHIELD SEAL - REMOVAL
(SHEET 1 OF 2)
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### Page 38

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
Refer to CMM 54-
52-06, Repair 2-1,
as an accepted pro-
cedure.
1323U8452-3VAPOR SEALRemove1
Refer to CMM 54-
52-06, Repair 2-1,
as an accepted pro-
cedure.
2323U8452-2BLOCK SEALRemove2
Bolts and washers.2-FASTENERRemove / Keep3
1-SEAL RETAINERRemove / Keep
1323U8852-1HEAT SHIELD SEALRemove
FIGURE 4: NO. 4 STRUT - VAPOR SEAL, BLOCK SEAL, AND HEAT SHIELD SEAL - REMOVAL
(SHEET 2 OF 2)
Export Controlled ECCN: 9E991 - BOEING
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BOEING SERVICE BULLETIN 747-54A2246
ALERTALERT

### Page 39 (OCR)

BOEING SERVICE BULLETIN 747-54A2246
ALERT  ALERT
NO. 1 OUTBOARD ENGINE
NO. 1 OUTBOARD STRUT
2461823
FIGURE 5: NO. 1 STRUT - STRUCTURAL INSPECTION FOR HEAT DAMAGE - DETAILED INSPECTION
AND EDDY CURRENT CONDUCTIVITY MEASUREMENT
(SHEET 1 OF 3)
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### Page 40 (OCR)

BOEING SERVICE BULLETIN 747-54A2246
ALERT  ALERT
NO. 1 AFT FAIRING FRAME ASSEMBLY
2461888
FIGURE 5: NO. 1 STRUT - STRUCTURAL INSPECTION FOR HEAT DAMAGE - DETAILED INSPECTION
AND EDDY CURRENT CONDUCTIVITY MEASUREMENT
(SHEET 2 OF 3)
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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 this figure.
More DataQtyIdentificationNameTaskStep
(a) (b)-321U8281-( )AFT STRUT BULK-
HEAD
Inspect1
(a) (b)-321U8730-( )DIAGONAL BRACE -
LUG
Inspect2
(a) (b)-321U8591-( )FITTING - UPPER
LATERAL RESTRAINT
Inspect3
(a) (b)-323U8701-( )AFT FAIRING, FRAME
1 ASSY
Inspect4
(a) (b)-323U8710-( )FWD LOWER SPAR -
OUTBOARD AFT
FAIRING
Inspect5
(a) Do a detailed inspection of the visible areas of the part for discoloration due to heat damage. Discolored
surfaces due to heat damage can include, but are not limited to, bare aluminum and the appearance of
all shades of white, brown, or black.
(b) Do an eddy current conductivity measurement in accordance with 747 NDT Manual Part 6, 51-00-00,
Procedure 3 for IACS values on the discolored areas of the part. Refer to TABLE 1 for acceptable IACS
values.
TABLE 1: Acceptable IACS Conductivity Inspection Values
ACCEPTABLE
CONDUCTIVITY
RANGES (%
IACS)
MATERIAL TYPEIDENTIFICATIONNAME
40.0-44.07050-T7452 Forging/BMS
7-214 Type 1
321U8281-( )AFT STRUT BULKHEAD
40.0-44.07050-T7451 Plate/BMS7-
323 Type 1
321U8730-( )DIAGONAL BRACE - LUG
31.0-35.02219-T851 Plate/AMS-QQ-
A-250/30
321U8591-( )FITTING - UPPER LATERAL
RESTRAINT
31.0-35.02219-T851 Plate/AMS-QQ-
A-250/30
323U8701-( )AFT FAIRING, FRAME 1
ASSY
31.0-35.02219-T851 Plate/AMS-QQ-
A-250/30
323U8710-( )FWD LOWER SPAR - OUT-
BOARD AFT FAIRING
FIGURE 5: NO. 1 STRUT - STRUCTURAL INSPECTION FOR HEAT DAMAGE - DETAILED INSPECTION
AND EDDY CURRENT CONDUCTIVITY MEASUREMENT
(SHEET 3 OF 3)
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
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BOEING SERVICE BULLETIN 747-54A2246
ALERTALERT

### Page 42 (OCR)

BOEING SERVICE BULLETIN 747-54A2246
ALERT  ALERT
NO. 4 OUTBOARD ENGINE
NO. 4 OUTBOARD STRUT
2461869
FIGURE 6: NO. 4 STRUT - STRUCTURAL INSPECTION FOR HEAT DAMAGE - DETAILED INSPECTION
AND EDDY CURRENT CONDUCTIVITY MEASUREMENT
(SHEET 1 OF 3)
Original Issue: February 05, 2016
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Work - See page 1 for details.  42 of 55

### Page 43 (OCR)

BOEING SERVICE BULLETIN 747-54A2246
ALERT  ALERT
NO. 4 AFT FAIRING FRAME ASSEMBLY
2461871
FIGURE 6: NO. 4 STRUT - STRUCTURAL INSPECTION FOR HEAT DAMAGE - DETAILED INSPECTION
AND EDDY CURRENT CONDUCTIVITY MEASUREMENT
(SHEET 2 OF 3)
Original Issue: February 05, 2016
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PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.  43 of 55

### Page 44

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
(a) (b)-321U8281-( )AFT STRUT BULK-
HEAD
Inspect1
(a) (b)-321U8730-( )DIAGONAL BRACE -
LUG
Inspect2
(a) (b)-321U8591-( )FITTING - UPPER
LATERAL RESTRAINT
Inspect3
(a) (b)-323U8701-( )AFT FAIRING, FRAME
1 ASSY
Inspect4
(a) (b)-323U8710-( )FWD LOWER SPAR -
OUTBOARD AFT
FAIRING
Inspect5
(a) Do a detailed inspection of the visible areas of the part for discoloration due to heat damage. Discolored
surfaces due to heat damage can include, but are not limited to, bare aluminum and the appearance of
all shades of white, brown, or black.
(b) Do an eddy current conductivity measurement in accordance with 747 NDT Manual Part 6, 51-00-00,
Procedure 3 for IACS values on the discolored areas of the part. Refer to TABLE 1 for acceptable IACS
values.
TABLE 1: Acceptable IACS Conductivity Inspection Values
ACCEPTABLE
CONDUCTIVITY
RANGES (%
IACS)
MATERIAL TYPEIDENTIFICATIONNAME
40.0-44.07050-T7452 Forging/BMS
7-214 Type 1
321U8281-( )AFT STRUT BULKHEAD
40.0-44.07050-T7451 Plate/BMS7-
323 Type 1
321U8730-( )DIAGONAL BRACE - LUG
31.0-35.02219-T851 Plate/AMS-QQ-
A-250/30
321U8591-( )FITTING - UPPER LATERAL
RESTRAINT
31.0-35.02219-T851 Plate/AMS-QQ-
A-250/30
323U8701-( )AFT FAIRING, FRAME 1
ASSY
31.0-35.02219-T851 Plate/AMS-QQ-
A-250/30
323U8710-( )FWD LOWER SPAR - OUT-
BOARD AFT FAIRING
FIGURE 6: NO. 4 STRUT - STRUCTURAL INSPECTION FOR HEAT DAMAGE - DETAILED INSPECTION
AND EDDY CURRENT CONDUCTIVITY MEASUREMENT
(SHEET 3 OF 3)
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
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BOEING SERVICE BULLETIN 747-54A2246
ALERTALERT

### Page 45 (OCR)

BOEING SERVICE BULLETIN 747-54A2246
ALERT  ALERT
VAPOR SEAL 1
_ A
HEATSHIELD SEAL
SEAL RETAINER
NO. 1 STRUT AFT FAIRING
2461911
FIGURE 7: NO. 1 STRUT - VAPOR SEAL, BLOCK SEAL, AND HEAT SHIELD SEAL - INSTALLATION
(SHEET 1 OF 4)
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### Page 46 (OCR)

BOEING SERVICE BULLETIN 747-54A2246
ALERT  ALERT
A-A
2461917
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.
FIGURE 7: NO. 1 STRUT - VAPOR SEAL, BLOCK SEAL, AND HEAT SHIELD SEAL - INSTALLATION
(SHEET 2 OF 4)
Original Issue: February 05, 2016
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Work - See page 1 for details.  46 of 55

### Page 47

More DataQtyIdentificationNameTaskStep
Fay surface seal be-
tween the aft fairing
frame and the vapor
seal to areas not
common with the
vapor seal retainer.
Refer to SOPM 20-
50-19 as an accept-
ed procedure.
-BMS 5-63FIREWALL SEALANTApply1
Refer to CMM 54-
52-06, Repair 2-1,
as an accepted pro-
cedure.
1323U8452-3VAPOR SEALInstall (New)
1323U8852-1HEAT SHIELD SEALInstall (New)2
1-SEAL RETAINERInstall (Kept)
Bolts and washers.
Torque the fastener
to 20-82 in-lbs.
2-FASTENERInstall (Kept)
Clean the fay sur-
face area on the
frame at the location
of the block seal in-
stallation. Refer to
SOPM 20-30-03 as
an accepted proce-
dure.
-323U8701-( )AFT FAIRING, FRAME
1 ASSY
Clean3
Apply adhesive to
the block seals. Re-
fer to CMM 54-52-
06, Repair 2-1, or
SOPM 20-50-12 as
an accepted proce-
dure.
--SILICONE ADHESIVE,
TYPE 60
Apply4
Bond the seals to
the frame. Refer to
CMM 54-52-06, Re-
pair 2-1, or SOPM
20-50-12 as an ac-
cepted procedure.
(a)
2323U8452-2BLOCK SEALInstall (New)5
FIGURE 7: NO. 1 STRUT - VAPOR SEAL, BLOCK SEAL, AND HEAT SHIELD SEAL - INSTALLATION
(SHEET 3 OF 4)
Export Controlled ECCN: 9E991 - BOEING
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BOEING SERVICE BULLETIN 747-54A2246
ALERTALERT

### Page 48

More DataQtyIdentificationNameTaskStep
Fill the gaps be-
tween the block
seals, vapor seals,
and heat shield seal.
Refer to CMM 54-
52-06, Repair 2-1, or
SOPM 20-50-19 as
an accepted proce-
dure.
-BMS 5-63FIREWALL SEALANTApply6
(a) Make sure the contour on the top of the block seals mates to the contour on the vapor seal.
FIGURE 7: NO. 1 STRUT - VAPOR SEAL, BLOCK SEAL, AND HEAT SHIELD SEAL - INSTALLATION
(SHEET 4 OF 4)
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BOEING SERVICE BULLETIN 747-54A2246
ALERTALERT

### Page 49 (OCR)

BOEING SERVICE BULLETIN 747-54A2246
ALERT  ALERT
VAPOR SEAL 1
_ A
HEATSHIELD SEAL
SEAL RETAINER
NO. 1 STRUT AFT FAIRING
2462253
FIGURE 8: NO. 4 STRUT - VAPOR SEAL, BLOCK SEAL, AND HEAT SHIELD SEAL - INSTALLATION
(SHEET 1 OF 4)
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### Page 50 (OCR)

BOEING SERVICE BULLETIN 747-54A2246
ALERT  ALERT
A-A
2461921
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.
FIGURE 8: NO. 4 STRUT - VAPOR SEAL, BLOCK SEAL, AND HEAT SHIELD SEAL - INSTALLATION
(SHEET 2 OF 4)
Original Issue: February 05, 2016
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Work - See page 1 for details.  50 of 55

### Page 51

More DataQtyIdentificationNameTaskStep
Fay surface seal be-
tween the aft fairing
frame and the vapor
seal to areas not
common with the
vapor seal retainer.
Refer to SOPM 20-
50-19 as an accept-
ed procedure.
-BMS 5-63FIREWALL SEALANTApply1
Refer to CMM 54-
52-06, Repair 2-1,
as an accepted pro-
cedure.
1323U8452-3VAPOR SEALInstall (New)
1323U8852-1HEAT SHIELD SEALInstall (New)2
1-SEAL RETAINERInstall (Kept)
Bolts and washers.
Torque the fastener
to 20-82 in-lbs.
2-FASTENERInstall (Kept)
Clean the fay sur-
face area on the
frame at the location
of the block seal in-
stallation. Refer to
SOPM 20-30-03 as
an accepted proce-
dure.
-323U8701-( )AFT FAIRING, FRAME
1 ASSY
Clean3
Apply adhesive to
the block seals. Re-
fer to CMM 54-52-
06, Repair 2-1, or
SOPM 20-50-12 as
an accepted proce-
dure.
--SILICONE ADHESIVE,
TYPE 60
Apply4
Bond the seals to
the frame. Refer to
CMM 54-52-06, Re-
pair 2-1, or SOPM
20-50-12 as an ac-
cepted procedure.
(a)
2323U8452-2BLOCK SEALInstall (New)5
FIGURE 8: NO. 4 STRUT - VAPOR SEAL, BLOCK SEAL, AND HEAT SHIELD SEAL - INSTALLATION
(SHEET 3 OF 4)
Export Controlled ECCN: 9E991 - BOEING
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Work - See page 1 for details.
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51 of 55
BOEING SERVICE BULLETIN 747-54A2246
ALERTALERT

### Page 52

More DataQtyIdentificationNameTaskStep
Fill the gaps be-
tween the block
seals, vapor seals,
and heat shield seal.
Refer to CMM 54-
52-06, Repair 2-1, or
SOPM 20-50-19 as
an accepted proce-
dure.
-BMS 5-63FIREWALL SEALANTApply6
(a) Make sure the contour on the top of the block seals mates to the contour on the vapor seal.
FIGURE 8: NO. 4 STRUT - VAPOR SEAL, BLOCK SEAL, AND HEAT SHIELD SEAL - INSTALLATION
(SHEET 4 OF 4)
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BOEING SERVICE BULLETIN 747-54A2246
ALERTALERT

### Page 53

Logic diagrams are provided as an aid only. Information contained in Paragraph 1.E., Compliance is the primary
source for compliance times. Information contained in Paragraph 3.B., Work Instructions is the primary source
for tasks required for compliance.
1. The table below gives the description for the parts and conditions called out in the logic diagrams.
DescriptionTitle
VAPOR SEAL DETAILED INSPECTION (SAFETY RELATED)PART 2
SEAL REPLACEMENT (SAFETY RELATED)PART 3
NO HEAT DAMAGE FOUND (VAPOR SEAL)CONDITION 1
ANY HEAT DAMAGE FOUND (VAPOR SEAL)CONDITION 2
2. The table below gives the description for the flag notes called out in the logic diagram.
DescriptionFlag Note Letter
Previous accomplishment of a detailed inspection of the visible surfaces of
the vapor seal from inside and outside the strut and aft fairing for heat damage,
a minimum of 10 inches from the bottom of the seal as shown in FIGURE 1
and FIGURE 2, meets the requirements of the detailed inspection of PART
2: VAPOR SEAL DETAILED INSPECTION (SAFETY RELATED).
(a)
Refer to 747-FTD-54-15002 for additional information related to this service
bulletin issue.
If the vapor seal (323U8452-3, QTY 1), block seals (323U8452-2, QTY 2),
and heat shield seal (323U8852-1, QTY 1) were all previously replaced at the
same time for an aft fairing, the compliance time is based on the number of
flight cycles from when all three seals were replaced on that aft fairing.
(b)
Boeing recommends accomplishment of PART 4: STRUCTURAL INSPECTION
AND REPAIR FOR HEAT DAMAGE (ECONOMIC RELATED) during PART
3: SEAL REPLACEMENT (SAFETY RELATED), before installation of new
seals. PART 4 is given as an economic consideration to prevent possible
operational disruptions.
(c)
After the accomplishment of PART 3: SEAL REPLACEMENT (SAFETY RE-
LATED), PART 2: VAPOR SEAL DETAILED INSPECTION (SAFETY RELAT-
ED) is accomplished within 1,800 flight cycles. Thereafter, PART 2: VAPOR
SEAL DETAILED INSPECTION (SAFETY RELATED) is repeated within 1,200
flight cycle intervals.
(d)
APPENDIX A:  LOGIC DIAGRAM FOR PARAGRAPH 1.E. COMPLIANCE: TABLE 1: NO. 1 AND NO. 4
STRUT AFT FAIRING - SAFETY RELATED - INITIAL AND REPEAT VAPOR SEAL INSPECTIONS AND
SEAL REPLACEMENT
(SHEET 1 OF 2)
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
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BOEING SERVICE BULLETIN 747-54A2246
ALERTALERT

### Page 54 (OCR)

BOEING SERVICE BULLETIN 747-54A2246
ALERT  ALERT
WHICHEVER OCCURS LATER
BEFORE 1,800 TOTAL
FLIGHT CYCLES OR WITHIN  WITHIN 6 MONTHS
VAPOR SEAL, BLOCK SEALS,  1,800 FLIGHT CYCLES AFTER  AND HEAT SHIELD SEAL  AFTER THE ORIGINAL  ISSUE DATE OF THIS
REPLACEMENT, WHICHEVER  SERVICE BULLETIN
OCCURS LATER
(a)
DO PART 2
(a)
CONDITION 1  CONDITION 2
BEFORE FURTHER
NOT TO EXCEED
FLIGHT
1,200 FLIGHT
CYCLES
ACTION 1:
DO PART 3
REPEAT  (c)
PART 2
WITHIN 1,800 FLIGHT
CYCLES
(a)
ACTION 2:
REPEAT PART 2
2461859
APPENDIX A: LOGIC DIAGRAM FOR PARAGRAPH 1.E. COMPLIANCE: TABLE 1: NO. 1 AND NO. 4
STRUT AFT FAIRING - SAFETY RELATED - INITIAL AND REPEAT VAPOR SEAL INSPECTIONS AND
SEAL REPLACEMENT
(SHEET 2 OF 2)
Original Issue: February 05, 2016
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PROPRIETARY - Copyright © Unpublished
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### Page 55 (OCR)

BOEING SERVICE BULLETIN 747-54A2246
ALERT  ALERT
Boeing Part Demand Intent
After review of this service bulletin (SB), Boeing asks that the primary engineer fill out this survey to
help Boeing predict the quantity and timing of the Boeing supplied kits.
Airline:
Contact Name:
Date:
Contact E-mail:
_ Yes  No Have/will you recommend to your airline to accomplish this SB?
• Yes  • No Would issuance of an Airworthiness Directive change this decision?
When would you likely be starting this SB incorporation? Month/ Year
How many airplanes per month do you plan to accomplish? Airplane/Month
How many total airplanes do you plan to complete? Total Airplanes
For inspection related SBs, are you planning to replace on condition, or a fleet campaign to replace on
all airplanes regardless of condition?
On Condition  Campaign
If you are not incorporating this SB at this time will you please help us understand the reason(s) why?
Your input will help us provide better customer support.
- Cost Prohibitive  Continue Inspections  L Other
Operator Comments:
Within 45 days of the SB issue, or as soon after as possible, please scan this form and send to:
sbsolutions@boeing.com
Disclaimer: The data provided in this survey will be used for planning purposes only and does not
constitute a commitment on any part of the airlines to purchase the parts in question, nor does it constitute
a commitment on the part of Boeing to deliver the parts in question. This survey is a projection to help
Boeing forecast demand levels and timing to better support the customers schedule.
2406495
APPENDIX B: PART DEMAND INTENT
(SHEET 1 OF 1)
Original Issue: February 05, 2016
Export Controlled ECCN: 9E991 - BOEING  747-54A2246
PROPRIETARY - Copyright © Unpublished  Work - See page 1 for details.  55 of 55

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