# Boeing Alert Service Bulletin 747-53A2860: Boeing - SB-747-53A2860-00

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- Title as filed: Boeing - SB-747-53A2860-00
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### Page 1

Commercial 
Airplanes
747
Service Bulletin
ALERT
Number: 747-53A2860
Original Issue: December 04, 2012
ATA System: 5312
SUBJECT: FUSELAGE - Main Frame - Center Section - Longeron Extension Fitting Inspection,
Repairs and Modification - Body Station 1480 to Body Station 1540
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 © 2012 Boeing.
Unpublished Work. All Rights Reserved.
Treatment of this document and its content is governed by contract with Boeing. Rights to use this document
are licensed on a per aircraft basis and such rights may not be transferable. For more information, contact The
Boeing Company.
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, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8A, 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. BOEING is a trademark of Boeing Management
Company.
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Table of Contents
Summary ...................................................... 5
1. PLANNING INFORMATION ........................................ 9
A. Effectivity ................................................ 9
1. Airplanes ............................................. 9
2. Spares Affected ........................................ 1 2
B. Concurrent Requirements ...................................... 1 2
C. Reason ................................................ 1 2
D. Description .............................................. 1 3
E. Compliance .............................................. 1 3
F. Approval ............................................... 1 6
G. Manpower .............................................. 1 6
H. Weight and Balance Changes .................................... 1 7
I. Electrical Load Data ......................................... 1 7
J. References .............................................. 1 8
1. Existing Data: ......................................... 1 8
2. Data Supplied with this Service Bulletin: ........................... 1 8
3. Installation Drawings Used in the Preparation of this Service Bulletin: ........... 1 8
K. Publications Affected ........................................ 1 8
L. Interchangeability and Intermixability of Parts ........................... 1 9
M. Software Accomplishment Summary ................................ 1 9
2. MATERIAL INFORMATION ........................................ 2 1
A. Material - Price and Availability ................................... 2 1
B. Industry Support Information .................................... 2 1
C. Parts Necessary for Each Airplane ................................. 2 1
1. Kits/Parts ............................................ 2 1
2. Parts and Materials Supplied by the Operator ........................ 2 1
3. Parts Modified and Reidentified ................................ 2 6
4. Parts Removed and Not Replaced .............................. 2 6
D. Parts Necessary to Change Spares ................................. 2 6
E. Special Tooling - Price and Availability ............................... 2 6
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 0
FIGURE 1: LONGERON EXTENSION FITTING INSPECTION ..................... 3 5
FIGURE 2: LONGERON EXTENSION FITTING CRACK REMOVAL (TEMPORARY REPAIR) .... 3 7
FIGURE 3: JACKING THE AIRPLANE FOR THE PERMANENT REPAIR OR THE PREVENTIVE
MODIFICATION ........................................ 4 1
FIGURE 4: INSPECTION OF LONGERON EXTENSION FITTINGS WITH THE TEMPORARY REPAIR
PREVIOUSLY ACCOMPLISHED ............................... 4 4
FIGURE 5: LONGERON EXTENSION FITTING TEMPORARY REPAIR TRIM PRIOR TO PERMANENT
REPAIR ACCOMPLISHMENT ................................. 4 6
FIGURE 6: INSPECTION OF THE LONGERON EXTENSION FITTING FOR THE PERMANENT REPAIR
OR PREVENTIVE MODIFICATION .............................. 5 0
FIGURE 7: LONGERON EXTENSION FITTING REMOVAL ....................... 5 2
FIGURE 8: LONGERON EXTENSION FITTING INSTALLATION [Group 1] ............... 5 9
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FIGURE 9: LONGERON EXTENSION FITTING INSTALLATION [Group 2] ............... 6 9
FIGURE 10: LONGERON EXTENSION FITTING INSTALLATION [Group 3] ............... 7 9
FIGURE 11: LONGERON EXTENSION FITTING INSURANCE TRIM PRIOR TO THE PREVENTIVE
MODIFICATION ........................................ 8 9
APPENDIX A: .................................................. 9 1
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Commercial 
Airplanes
747
Service Bulletin
ALERT
SummaryNumber: 747-53A2860Original Issue: December 04, 2012
ATA System: 5312
SUBJECT: FUSELAGE - Main Frame - Center Section - Longeron Extension Fitting Inspection,
Repairs and Modification - Body Station 1480 to Body Station 1540
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 gives instructions to do inspections, repair and modification of the longeron extension fittings
at left and right Body Station (STA) 1480 for cracks. Cracks in the longeron extension fittings that are not found
and repaired can become large and adversely affect the structural integrity of the airplane.
Longeron extension fittings are installed on the fuselage skin from STA 1480 to STA 1540 under the wing-to-body
fairing, and attach the overwing longeron to the fuselage skin in Section 46. Operators have told Boeing that
thirteen cracked longeron extension fittings were found on eight airplanes. The cracks were found in the outboard
flange of the fitting, which attaches to the wing-to-body fairing support frame web. Service history is given in the
table that follows:
Service History
Flight-HoursFlight-Cycles
Crack Length
Model Right Side Left Side
29,8123,2300.375-747-400
47,6908,1080.5000.125747-400F
48,0338,2131.7000.300747-400F
48,9218,3680.500.30747-400F
51,1248,8630.5000.125747-400F
52,2388,9880.070-747-400F
56,1249,850-0.188747-400
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Service History
Flight-HoursFlight-Cycles
Crack Length
Model Right Side Left Side
59,2329,6140.4000.240747-400F
Analysis by Boeing indicates that these cracks are caused by fatigue combined with preload stress from improper
fit-up during assembly. A manufacturing process change that began at line number 1199 may have resulted in
preloading the longeron extension fittings.
Accomplishment of the longeron extension fitting inspections, repairs and modification in this service bulletin
will make sure that cracks in the longeron extension fittings are found and repaired before they can become
large and adversely affect the structural integrity of the airplane.
Boeing Fleet Team Digest (FTD) 747 FTD 53-11007 is related to this service bulletin.
Boeing Service Related Problem (SRP) 747-SRP-53-0398 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., ComplianceYesAD 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 Material
Paragraph 2.F., Special Tooling Necessary to
do this Service Bulletin
YesSpecial Tooling Required
ACTION (PRR 85901-119RS)
Get access to the longeron extension fittings on the fuselage skin on the left and right sides of the airplane under
the wing-to-body fairings at STA 1480. Do surface High Frequency Eddy Current (HFEC) inspections of the
longeron extension fitting on the left and right sides of the airplane for cracks in accordance with this service
bulletin.
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If any crack is found that is within the limits given in this service bulletin, do the Temporary Repair in accordance
with this service bulletin. At the time given in this service bulletin, also do the Permanent Repair in accordance
with this service bulletin. If any crack is found that is not within the limits given in this service bulletin, replace
the fitting in accordance with this service bulletin.
If no crack is found, put the airplane back to a serviceable condition. Do the surface HFEC inspection again at
the time given in this service bulletin. As an alternative to repeat inspections, do the Preventive Modification in
accordance with this service bulletin.
EFFECTIVITY
747-400 and 747-400F 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.
INDUSTRY SUPPORT INFORMATION
Boeing warranty remedies are available for airplanes in warranty as of September 14, 2011. Please refer to
Paragraph 2.B., Industry Support Information.
MANPOWER
Elapsed HoursTotal Task HoursTask
9.5032.00Longeron Extension Fitting Inspection
125.00479.00Longeron Extension Fitting Preventive
Modification
115.00464.00Longeron Extension Fitting Replacement
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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BOEING SERVICE BULLETIN 747-53A2860
ALERT  ALERT
STA
1480
LONGERON
EXTENSION
FITTING
FUSELAGE SKIN
STA
1480
LONGERON
EXTENSION
FITTING
DO A SURFACE HFEC INSPECTION
OF THE LONGERON EXTENSION
FITTING FOR CRACKS. IF CRACKS
ARE FOUND, REPAIR IF WITHIN
LIMITS OR REPLACE THE FITTING  TYPICAL
IF NOT WITHIN LIMITS. AS AN  CRACK
ALTERNATIVE TO REPEAT
INSPECTIONS, REMOVE UNCRACKED
FITTINGS AND REINSTALL WITH
SHIMS,OR REPLACE CRACKED  2167176
FITTINGS WITH NEW FITTINGS,
INSTALLED WITH SHIMS.
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### Page 9

Commercial 
Airplanes
747
Service Bulletin
ALERT
Number: 747-53A2860
Original Issue: December 04, 2012
ATA System: 5312
SUBJECT: FUSELAGE - Main Frame - Center Section - Longeron Extension Fitting Inspection,
Repairs and Modification - Body Station 1480 to Body Station 1540
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
Refer to Service Bulletin Index D6-30300 Part 3 for Airplane Variable Number, Line Number, and
Serial Number data.
This service bulletin is for the airplanes shown below. Refer to PRR 85901-119RS for data about
this change.
DESCRIPTIONCONFIGURATIONGROUP
747-400 and 747-400F airplanes line number 1199-1238.-1
747-400 and 747-400F airplanes line number 1239-1307, 1309-1312,
1314, 1324-1325, 1327, 1335-1337, 1343, 1353-1354 and 1357-1358.
-2
747-400 and 747-400F airplanes line number 1308, 1313, 1315-1323,
1326, 1328-1334, 1338-1342, 1344-1352, 1355-1356, and 1359-1419.
-3
Airplane Models:
747-400, 747-400F
GroupVariable Number
3RF001 - RF006
2RL401 - RL403
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GroupVariable Number
2RL411 - RL420
3RL421 - RL436
3RL451 - RL456
3RL461 - RL462
3RL471 - RL481
3RL491 - RL492
3RL501 - RL502
3RL511 - RL516
3RL521 - RL522
3RL531 - RL534
3RL551
3RL561 - RL568
3RL571 - RL572
3RL576 - RL577
3RL579
3RL581 - RL586
2RL651 - RL655
3RL671 - RL675
3RL681 - RL684
2RL751 - RL752
1RM002 - RM003
2RM004 - RM007
2RM010
2RM013
1RM024
1RM027
2RM028 - RM030
2RM039 - RM045
2RM052 - RM053
1RM091
1RM129 - RM131
2RM132
1RM157
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GroupVariable Number
2RM158
1RM171 - RM176
2RM177
1RM192
1RM231 - RM232
2RM233
1RM241 - RM244
2RM245 - RM246
1RM263 - RM264
1RM316
2RM317 - RM318
1RM331 - RM332
2RM333
2RM341
2RM351 - RM355
2RM366 - RM367
2RM401 - RM403
2RM426
2RM431
2RM441 - RM443
2RM445
1RM801
2RM802 - RM803
1RM813
1RM852
2RM853 - RM858
3RM859
1RM861
2RM862
3RM863
2RM872 - RM876
3RM877 - RM880
1RM882 - RM885
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GroupVariable Number
2RM886 - RM887
3RM888 - RM890
1RM896 - RM899
2RM901 - RM905
3RM906
1RM911
2. Spares Affected
None.
B. Concurrent Requirements
None.
C. Reason
This service bulletin gives instructions to do inspections, repair and modification of the longeron extension
fittings at left and right Body Station (STA) 1480 for cracks. Cracks in the longeron extension fittings
that are not found and repaired can become large and adversely affect the structural integrity of the
airplane.
Longeron extension fittings are installed on the fuselage skin from STA 1480 to STA 1540 under the
wing-to-body fairing, and attach the overwing longeron to the fuselage skin in Section 46. Operators
have told Boeing that thirteen cracked longeron extension fittings were found on eight airplanes. The
cracks were found in the outboard flange of the fitting, which attaches to the wing-to-body fairing support
frame web. Service history is given in the table that follows:
Service History
Flight-HoursFlight-Cycles
Crack Length
Model Right Side Left Side
29,8123,2300.375-747-400
47,6908,1080.5000.125747-400F
48,0338,2131.7000.300747-400F
48,9218,3680.500.30747-400F
51,1248,8630.5000.125747-400F
52,2388,9880.070-747-400F
56,1249,850-0.188747-400
59,2329,6140.4000.240747-400F
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### Page 13

Analysis by Boeing indicates that these cracks are caused by fatigue combined with preload stress
from improper fit-up during assembly. A manufacturing process change that began at line number 1199
may have resulted in preloading the longeron extension fittings.
Accomplishment of the longeron extension fitting inspections, repairs and modification in this service
bulletin will make sure that cracks in the longeron extension fittings are found and repaired before they
can become large and adversely affect the structural integrity of the airplane.
Boeing Fleet Team Digest (FTD) 747 FTD 53-11007 is related to this service bulletin.
Boeing Service Related Problem (SRP) 747-SRP-53-0398 is related to this service bulletin.
D. Description
Get access to the longeron extension fittings on the fuselage skin on the left and right sides of the
airplane under the wing-to-body fairings at STA 1480. Do surface High Frequency Eddy Current (HFEC)
inspections of the longeron extension fitting on the left and right sides of the airplane for cracks in
accordance with this service bulletin.
If any crack is found that is within the limits given in this service bulletin, do the Temporary Repair in
accordance with this service bulletin. At the time given in this service bulletin, also do the Permanent
Repair in accordance with this service bulletin. If any crack is found that is not within the limits given
in this service bulletin, replace the fitting in accordance with this service bulletin.
If no crack is found, put the airplane back to a serviceable condition. Do the surface HFEC inspection
again at the time given in this service bulletin. As an alternative to repeat inspections, do the Preventive
Modification in accordance with this service bulletin.
The work in this service bulletin is done in the maintenance zone(s) given below.
Affected Maintenance Zones
ZoneModel
141, 142, 143, 144747-400, 747-400F
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.
Accomplish the required actions, based on the applicable conditions in Table 1 and Table 2 , in
accordance with Paragraph 3. Accomplishment Instructions.
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Table 1: STA 1480 Longeron Extension Fitting Inspection
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
-Within 2,100
flight-cycles af-
ter the original
issue date of
this service bul-
letin.
Before 3,000 to-
tal flight-cycles.
Do surface HFEC inspec-
tions of the left and right
longeron extension fit-
tings for cracks in accor-
dance with Paragraph
3.B., Work Instructions,
PART 1.
All airplanes.
--Before further
flight.
Do the Temporary Repair
in accordance with Para-
graph 3.B., Work Instruc-
tions, PART 2.
Any crack found. All cracks
are within limits.
OR
--Before further
flight.
Do the Permanent Repair
in accordance with Para-
graph 3.B., Work Instruc-
tions, PART 4. (a)
--Before further
flight.
Do the Longeron Exten-
sion Fitting Replacement
in accordance with Para-
graph 3.B., Work Instruc-
tions, PART 6. (b)
Any crack found that is not
within limits.
2,100 flight-cycles
(a) (b) (c)
--Repeat the surface HFEC
inspection of the forward
flange of the left and right
longeron extension fitting
in accordance with Para-
graph 3.B., Work Instruc-
tions, PART 1.
No crack found.
OR
--Before further
flight.
Do the Preventive Modifi-
cation in accordance with
Paragraph 3.B., Work In-
structions, PART 5. (c)
--At the times in
Table 2 of Para-
graph 1.E.,
Compliance.
In accordance with Table
2 of Paragraph 1.E.,
Compliance:
Do an inspection of the
Temporary Repair.
Airplanes on which the
temporary repair has been
done in accordance with
Paragraph 3.B., Work In-
structions, PART 2.
AND
Do a permanent repair or
Longeron Extension Fit-
ting Replacement.
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### Page 15

Table 1: STA 1480 Longeron Extension Fitting Inspection
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
(a) To terminate the repetitive inspections in this service bulletin, do the Permanent Repair in accordance
with Paragraph 3.B., Work Instructions, PART 4.
(b) To terminate the repetitive inspections in this service bulletin, do the Longeron Extension Fitting Replace-
ment in accordance with Paragraph 3.B., Work Instructions, PART 6.
(c) To terminate the repetitive inspections in this service bulletin, do the Preventive Modification in accordance
with Paragraph 3.B., Work Instructions, PART 5.
Table 2: Permanent Repair of Longeron Extension Fittings with the Temporary Repair Previously Ac-
complished
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
--Within 1,000
flight-cycles af-
ter accomplish-
ment of the
Temporary Re-
pair.
Do a surface HFEC in-
spection of the Tempo-
rary Repair of the
longeron extension fit-
tings for cracks in accor-
dance with Paragraph
3.B., Work Instructions,
PART 3.
Temporary Repair previous-
ly accomplished in accor-
dance with Paragraph 3.B.,
Work Instructions, PART 2.
--Before further
flight.
Do the Permanent Repair
in accordance with Para-
graph 3.B., Work Instruc-
tions, PART 4. (a)
Any crack found. All cracks
are within limits.
--Before further
flight.
Do the Longeron Exten-
sion Fitting Replacement
shown in Paragraph 3.B.,
Work Instructions, PART
6. (b)
Any crack found that is not
within limits.
--Before further
flight.
Do the Permanent Repair
in accordance with Para-
graph 3.B., Work Instruc-
tions, PART 4. (a)
No crack found.
(a) To terminate the repetitive inspections in this service bulletin, do the Permanent Repair in accordance
with Paragraph 3.B., Work Instructions, PART 4.
(b) To terminate the repetitive inspections in this service bulletin, do the Longeron Extension Fitting Replace-
ment in accordance with Paragraph 3.B., Work Instructions, PART 6.
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### Page 16

F. Approval
This service bulletin was examined by the Federal Aviation Administration (FAA). The changes specified
in this service bulletin comply with the applicable regulations and are FAA approved, as well as European
Aviation Safety Agency (EASA)/Joint Aviation Authorities (JAA) approved for all EASA/JAA approved
airplanes listed in the service bulletin effectivity. This service bulletin and its approval were based on
the airplane in its original Boeing delivery configuration or as modified by other approved Boeing
changes.
If an airplane has a non-Boeing modification or repair that affects a component or system also affected
by this service bulletin, the operator is responsible for obtaining appropriate regulatory agency approval
before incorporating this service bulletin.
G. Manpower
The table below shows an estimate of the task hours necessary to do this inspection, repair or
modification 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 - Longeron Extension Fitting Inspection
Elapsed HoursTask HoursNumber of PersonsTask
1.887.504Open Access
1.001.001Inspect (Figure 1)
1.887.504Close Access
4.7516.00TOTAL FOR ONE SIDE OF THE AIRPLANE
9.5032.00TOTAL FOR EACH AIRPLANE
NOTE: More time will be necessary for repairs if cracks are found.
Table 2 - Longeron Extension Fitting Preventive Modification
Elapsed HoursTask HoursNumber of PersonsTask
3.7515.004Open Access
1.005.005Jack the Airplane
(Figure 3)
2.502.501Inspect (Figure 6)
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Table 2 - Longeron Extension Fitting Preventive Modification
Elapsed HoursTask HoursNumber of PersonsTask
16.0064.004Longeron Extension
Fitting Removal (Fig-
ure 7)
2.505.002Longeron Extension
Fitting Trim (Figure
11)
32.00128.004Longeron Extension
Fitting Installation
(Figure 8, 9 or 10)
1.005.005Dejack the Airplane
3.7515.004Close Access
62.50239.50TOTAL FOR ONE SIDE OF THE AIRPLANE
125.00479.00TOTAL FOR EACH AIRPLANE
NOTE: More time will be necessary for repairs if cracks are found.
Table 3 - Longeron Extension Fitting Replacement
Elapsed HoursTask HoursNumber of PersonsTask
3.7515.004Open Access
1.005.005Jack the Airplane
(Figure 3)
16.0064.004Longeron Extension
Fitting Removal (Fig-
ure 7)
32.00128.004Longeron Extension
Fitting Installation
(Figure 8, 9 or 10)
1.005.005Dejack the Airplane
3.7515.004Close Access
57.50232.00TOTAL FOR ONE SIDE OF THE AIRPLANE
115.00464.00TOTAL FOR EACH AIRPLANE
H. Weight and Balance Changes
None.
I. Electrical Load Data
Not changed.
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J. References
1. Existing Data:
a. Engineering Change Memo PRR 85901-119RS
b. Boeing Service Letter 747-SL-51-048
c. Boeing Service Related Problem (SRP) 747-SRP-53-0398
d. Service Bulletin Index D6-30300
e. Standard Overhaul Practices Manual (SOPM) 20-10-03, 20-41-02, 20-50-19, 20-50-20
f. 747 Fleet Team Digest (FTD) 53-11007
g. 747 Non-Destructive Testing (NDT) Manual Part 6, 51-00-00
h. 747-400 Aircraft Maintenance Manual (AMM) 07-10-00, 12-15-04, 25-52-01, 25-52-04,
51-21-04, 51-24-13
i. 747-400 Structural Repair Manual (SRM) 51-20-06, 51-40-09
j. 747-400F Structural Repair Manual (SRM) 51-20-06, 51-40-09
k. 747-400SF Structural Repair Manual (SRM) 51-40-09
2. Data Supplied with this Service Bulletin:
None.
3. Installation Drawings Used in the Preparation of this Service Bulletin:
TitleDrawing Number
Skin, Frame, Stringer Instl - S-23 to WL 154.38 STA 1350 to STA
1480
65B01162
Crease Beam and WL 152 Deck Instl65B15254
Longeron Extension Fitting Installation65B15255
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
747 Aircraft Maintenance Manual
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Chapter-SectionPublication
747 Corrosion Prevention Manual
747 Structural Repair Manual
747 Weight and Balance 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 but no new DTIs are necessary.
L. Interchangeability and Intermixability of Parts
Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts.
M. Software Accomplishment Summary
Not affected.
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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, if needed. As an alternative, operators can purchase the parts from Boeing Spares. This
service bulletin does not show the Boeing price and supply data.
B. Industry Support Information
Boeing warranty remedies are available for 747 airplanes in warranty as of September 14, 2011. For
inspection task hour reimbursement for airplanes in warranty as of that date, send a warranty claim to
Boeing Commercial Airplanes Group - Warranties. If the condition described in this service bulletin is
found during the inspection for airplanes in warranty as of that date and additional task hours and parts
are required, send a warranty claim to Boeing Commercial Airplanes Group - Warranties. Please refer
to this service bulletin number and reference the airplane variable number(s) in your purchase order.
C. Parts Necessary for Each Airplane
1. Kits/Parts
None.
2. Parts and Materials Supplied by the Operator
NOTE: Refer to 747 Structural Repair Manual Chapter 51 for alternate fasteners.1.
2. Refer to the Qualified Products List at the end of the Boeing Material Specification
(BMS) for supplier data.
3. The numbers given in the QTY columns in the tables below are the number of
parts necessary for one side of the airplane.
Group 1:
NotesNameQTYPart Number / Specifi-
cation
Use 65B15034U22 for the right
Longeron Extension Fitting
Left Longeron Extension
Fitting
-65B15034U21
-Sealant1
quart
BMS 5-95
-Primer1 pintBMS 10-11, Type I
-Bolt3BACB30MY6K2X
-Bolt3BACB30MY6K6X
-Bolt1BACB30MY6K7X
-Bolt2BACB30MY6K10X
-Bolt1BACB30MY6K12X
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Group 1:
NotesNameQTYPart Number / Specifi-
cation
-Bolt8BACB30MY8K4X
-Bolt20BACB30MY8K5X
-Bolt16BACB30MY8K6X
-Bolt40BACB30MY8K7X
-Bolt36BACB30MY8K8X
-Bolt49BACB30MY8K9X
-Bolt25BACB30MY8K10X
-Bolt12BACB30MY8K11X
-Bolt4BACB30MY8K12X
-Bolt1BACB30MY8K21X
-Bolt1BACB30MY8K23X
-Bolt1BACB30NW12K9X
-Bolt4BACB30US8K26
-Bolt4BACB30US8K28
-Bolt4BACB30US8K33
-Bolt2BACB30US9K27
-Bolt2BACB30US9K30
-Bolt4BACB30US9K21
-Bolt4BACB30US9K34
-Collar10BACC30M6
-Collar211BACC30M8
-Collar1BACC30M12
-Nut12BACN10HR8CD
-Nut12BACN10HR9CD
-Shim1BACS40R034B053F
-Shim1BACS40R034B060F
-Shim2BACS40R027B049F
-Shim1BACS40R018B025F
-Shim3BACS40R018E055F
-Shim3BACS40R021E055F
-Shim2BACS40R024E096F
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Group 1:
NotesNameQTYPart Number / Specifi-
cation
-Shim165B15254-245
-Washer12BACW10BP8CD
-Washer12BACW10BP8DP
-Washer12BACW10BP9CD
-Washer12BACW10BP9DP
-Washer - Self Aligning1BACW10CA6CCK
-Washer - Self Aligning1BACW10CA6PVK
Group 2:
NotesNameQTYPart Number / Specifi-
cation
Use 65B15034U24 for the right
Longeron Extension Fitting
Left Longeron Extension
Fitting
-65B15034U23
-Sealant1
quart
BMS 5-95
-Primer1 pintBMS 10-11, Type I
-Bolt3BACB30MY6K2X
-Bolt3BACB30MY6K6X
-Bolt1BACB30MY6K7X
-Bolt2BACB30MY6K10X
-Bolt1BACB30MY6K12X
-Bolt8BACB30MY8K4X
-Bolt19BACB30MY8K5X
-Bolt16BACB30MY8K6X
-Bolt40BACB30MY8K7X
-Bolt36BACB30MY8K8X
-Bolt49BACB30MY8K9X
-Bolt28BACB30MY8K10X
-Bolt12BACB30MY8K11X
-Bolt4BACB30MY8K12X
-Bolt1BACB30MY8K21X
-Bolt1BACB30MY8K23X
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Group 2:
NotesNameQTYPart Number / Specifi-
cation
-Bolt1BACB30NW12K9X
-Bolt4BACB30US8K26
-Bolt4BACB30US8K28
-Bolt4BACB30US8K33
-Bolt2BACB30US9K27
-Bolt2BACB30US9K30
-Bolt4BACB30US9K21
-Bolt4BACB30US9K34
-Collar10BACC30M6
-Collar214BACC30M8
-Collar1BACC30M12
-Nut12BACN10HR8CD
-Nut12BACN10HR9CD
-Shim1BACS40R034B053F
-Shim1BACS40R034B060F
-Shim2BACS40R027B049F
-Shim1BACS40R018B025F
-Shim3BACS40R018E055F
-Shim3BACS40R021E055F
-Shim2BACS40R024E096F
-Shim165B15254-245
-Washer12BACW10BP8CD
-Washer12BACW10BP8DP
-Washer12BACW10BP9CD
-Washer12BACW10BP9DP
-Washer - Self Aligning1BACW10CA6CCK
-Washer - Self Aligning1BACW10CA6PVK
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Group 3:
NotesNameQTYPart Number / Specifi-
cation
Use 65B15034U26 for the right
Longeron Extension Fitting
Left Longeron Extension
Fitting
-65B15034U25
-Sealant1
quart
BMS 5-95
-Primer1 pintBMS 10-11, Type I
-Bolt3BACB30MY6K2X
-Bolt3BACB30MY6K6X
-Bolt1BACB30MY6K7X
-Bolt2BACB30MY6K10X
-Bolt1BACB30MY6K12X
-Bolt8BACB30MY8K4X
-Bolt19BACB30MY8K5X
-Bolt16BACB30MY8K6X
-Bolt40BACB30MY8K7X
-Bolt36BACB30MY8K8X
-Bolt49BACB30MY8K9X
-Bolt27BACB30MY8K10X
-Bolt12BACB30MY8K11X
-Bolt4BACB30MY8K12X
-Bolt1BACB30MY8K21X
-Bolt1BACB30MY8K23X
-Bolt1BACB30NW12K9X
-Bolt4BACB30US9K21
-Bolt4BACB30US9K26
-Bolt2BACB30US9K27
-Bolt4BACB30US9K28
-Bolt2BACB30US9K30
-Bolt4BACB30US9K33
-Bolt4BACB30US9K34
-Collar10BACC30M6
-Collar213BACC30M8
-Collar1BACC30M12
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Group 3:
NotesNameQTYPart Number / Specifi-
cation
-Nut24BACN10HR9CD
-Shim1BACS40R034B053F
-Shim1BACS40R034B060F
-Shim2BACS40R027B049F
-Shim1BACS40R018B025F
-Shim3BACS40R018E055F
-Shim3BACS40R021E055F
-Shim2BACS40R024E096F
-Shim165B15254-245
-Washer24BACW10BP9CD
-Washer24BACW10BP9DP
-Washer - Self Aligning1BACW10CA6CCK
-Washer - Self Aligning1BACW10CA6PVK
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
The 747-400 SRM 51-40-09, 747-400F SRM 51-40-09 and 747-400SF SRM 51-40-09 give data about
cold working tools and sleeves necessary to do the Longeron Extension Fitting Replacement given in
this service bulletin. These tools are available from industry sources.
Engineering, service, and a kit of cold working tools made for this change are available from Fatigue
Technology, Inc. or West Coast Industries, Inc.
 Refer To: FTI Kit Number: FTI-747-53-2860-1
Fatigue Technology, Inc.
P.O. Box C-88388
Seattle, WA 98188 USA
Phone Number (206) 246-2010
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Fax (206) 244-9886
 Refer To: WCI Kit Number: WCI-747-53A-2860
West Coast Industries, Inc.
14900 Whitman Avenue North
Seattle, WA 98133-6532 USA
Phone Number (206) 365-7513
Fax (206) 365-7483
F. Special Tooling Necessary to do this Service Bulletin
Cold working tools are necessary to do the Longeron Extension Fitting Replacement given in this
service bulletin. To get the cold working tools, refer to Paragraph 2.E., Special Tooling - Price and
Availability.
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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 limits to tighten nuts and bolts are in SRM Chapter 51
4. Use the approved fastener and process 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.
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.
7. A General Visual Inspection is defined as: A visual examination of an interior or
exterior area, installation or assembly to detect obvious damage, failure or irregularity.
This level of inspection is made from within touching distance unless otherwise
specified. A mirror may be necessary to enhance visual access to all exposed surfaces
in the inspection area. This level of inspection is made under normally available
lighting conditions such as daylight, hangar lighting, flashlight or drop-light and may
require removal or opening of access panels or doors. Stands, ladders or platforms
may be required to gain proximity to the area being checked.
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8. These work instructions refer to procedures included in other Boeing documents.
When the words "refer to" are used and the operator has an accepted alternative
procedure, the accepted alternative procedure can be used. When the words "in
accordance with" are included in the instruction, the procedure in the Boeing document
must be used.
9. 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.
10. Refer to Appendix A for a Master Fastener Table.
11. 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.
12. 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.
13. 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.
14. Some Boeing parts are supplied in a temporary configuration. Those parts are
identified with a 'U', 'W', or 'Y' in place of the '-' (dash) in the part number. It is
permitted to install parts identified with a 'U', 'W', or 'Y' as an alternative to the '-'
(dash) part number. Boeing Drawing 005W0900 contains more data.
15. Refer to 747-400 AMM 51-21-04 as an accepted procedure for application of chemical
conversion coating to aluminum parts.
16. Refer to SOPM 20-41-02 as an accepted procedure for application of finishes.
17. Refer to SOPM 20-50-19 as an accepted procedure for application of sealant.
B. WORK INSTRUCTIONS
PART 1 - Longeron Extension Fitting Inspection
1. Remove wing-to-body fairing panels 293C, 293H and 293K (left side) and 294C, 294H and 294K
(right side), for external access to the inspection area.
2. Do surface HFEC inspections of the left and right longeron extension fittings for cracks in accordance
with FIGURE 1.
3. If all cracks are within the limits shown in FIGURE 2, do one of the following:
a. Do the Temporary Repair in accordance with PART 2.
b. Do the Permanent Repair in accordance with PART 4.
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4. If any crack is not within the limits shown in FIGURE 2, do the Longeron Extension Fitting
Replacement in accordance with PART 6.
5. If no crack is found, do one of the following:
a. Install wing-to-body fairing panels 293C, 293H and 293K (left side) and 294C, 294H and 294K
(right side). Put the airplane back to a serviceable condition. Repeat the inspection in
accordance with PART 1 at the time given in Paragraph 1.E., Compliance, Table 1.
b. Do the Preventive Modification in accordance with PART 5.
PART 2 - Temporary Repair
1. Do the Temporary Repair by removing longeron extension fitting cracks in accordance with FIGURE
2.
2. Install wing-to-body fairing panels 293C, 293H and 293K (left side) and 294C, 294H and 294K
(right side). Put the airplane back to a serviceable condition. Do an inspection in accordance with
PART 3 at the time given in Paragraph 1.E., Compliance, Table 2.
PART 3 - Inspection of Longeron Extension Fittings with the Temporary Repair Previously
Accomplished
1. Remove wing-to-body fairing panels 293C, 293H and 293K (left side) and 294C, 294H and 294K
(right side), for external access to the inspection area.
2. Get internal access to the fasteners in the affected longeron extension fitting. In the aft lower lobe
cargo compartment, remove sidewall and ceiling linings and insulation blankets as necessary to
access the fuselage skin in the area from STA 1480 to STA 1540. Refer to 747-400 AMM 25-52-01
and 747-400 AMM 25-52-04 as accepted procedures.
3. Jack the airplane in accordance with FIGURE 3.
4. Remove the longeron extension fitting in accordance with FIGURE 7.
5. Do a surface HFEC inspection of the Temporary Repair of the longeron extension fitting for cracks
in accordance with FIGURE 4.
6. If any crack is found:
a. If all cracks are within the limits shown in FIGURE 2, remove any longeron extension fitting
cracks in accordance with FIGURE 2 and do the Permanent Repair in accordance with PART
4.
b. If any crack is not within the limits shown in FIGURE 2, do the Longeron Extension Fitting
Replacement in accordance with PART 6.
7. If no crack is found, do an additional insurance trim in the area of the Temporary Repair in
accordance with FIGURE 5 and do the Permanent Repair in accordance with PART 4.
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PART 4 - Permanent Repair
1. If not done previously, get internal access to the fasteners in the affected longeron extension fitting.
In the aft lower lobe cargo compartment, remove sidewall and ceiling linings and insulation blankets
as necessary to access the fuselage skin in the area from STA 1480 to STA 1540. Refer to 747-400
AMM 25-52-01 and 747-400 AMM 25-52-04 as accepted procedures.
2. If not done previously, jack the airplane in accordance with FIGURE 3.
3. Do open-hole HFEC inspections for cracks in accordance with FIGURE 6.
4. Remove the longeron extension fitting in accordance with FIGURE 7.
5. If any crack is found, contact Boeing for repair instructions and do the repair.
6. Group 1:
Install the longeron extension fitting in accordance with FIGURE 8. After installation, finish the
area to match adjacent structure.
7. Group 2:
Install the longeron extension fitting in accordance with FIGURE 9. After installation, finish the
area to match adjacent structure.
8. Group 3:
Install the longeron extension fitting in accordance with FIGURE 10. After installation, finish the
area to match adjacent structure.
9. Reapply corrosion inhibiting compound, BMS3-35, BMS3-23, Type II or BMS3-29 to the affected
area. Refer to 747-400 AMM 51-24-13 as an accepted procedure.
10. Dejack the airplane. Refer to 747-400 AMM 07-10-00 as an accepted procedure.
11. Install any aft lower lobe cargo compartment sidewall and ceiling linings and insulation blankets
that were removed for internal access to the fasteners in the affected longeron extension fitting.
Refer to 747-400 AMM 25-52-01 and 747-400 AMM 25-52-04 as accepted procedures.
12. Install wing-to-body fairing panels 293C, 293H and 293K (left side) and 294C, 294H and 294K
(right side).
13. Put the airplane back to a serviceable condition.
PART 5 - Preventive Modification
1. Get internal access to the fasteners in the affected longeron extension fitting. In the aft lower lobe
cargo compartment, remove sidewall and ceiling linings and insulation blankets as necessary to
access the fuselage skin in the area from STA 1480 to STA 1540. Refer to 747-400 AMM 25-52-01
and 747-400 AMM 25-52-04 as accepted procedures.
2. If not done previously, jack the airplane in accordance with FIGURE 3.
3. Do open-hole HFEC inspections for cracks in accordance with FIGURE 6.
4. Remove the longeron extension fitting in accordance with FIGURE 7.
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5. If any crack is found, contact Boeing for repair instructions and do the repair.
6. Do an insurance trim on the longeron extension fitting in accordance with FIGURE 11.
7. Group 1:
Install the longeron extension fitting in accordance with FIGURE 8. After installation, finish the
area to match adjacent structure.
8. Group 2:
Install the longeron extension fitting in accordance with FIGURE 9. After installation, finish the
area to match adjacent structure.
9. Group 3:
Install the longeron extension fitting in accordance with FIGURE 10. After installation, finish the
area to match adjacent structure.
10. Reapply corrosion inhibiting compound, BMS3-35, BMS3-23, Type II or BMS3-29 to the affected
area. Refer to 747-400 AMM 51-24-13 as an accepted procedure.
11. Dejack the airplane. Refer to 747-400 AMM 07-10-00 as an accepted procedure.
12. Install any aft lower lobe cargo compartment sidewall and ceiling linings and insulation blankets
that were removed for internal access to the fasteners in the affected longeron extension fitting.
Refer to 747-400 AMM 25-52-01 and 747-400 AMM 25-52-04 as accepted procedures.
13. Install wing-to-body fairing panels 293C, 293H and 293K (left side) and 294C, 294H and 294K
(right side).
14. Put the airplane back to a serviceable condition.
PART 6 - Longeron Extension Fitting Replacement
1. If not done previously, get internal access to the fasteners in the affected longeron extension fitting.
In the aft lower lobe cargo compartment, remove sidewall and ceiling linings and insulation blankets
as necessary to access the fuselage skin in the area from STA 1480 to STA 1540. Refer to 747-400
AMM 25-52-01 and 747-400 AMM 25-52-04 as accepted procedures.
2. If not done previously, jack the airplane in accordance with FIGURE 3.
3. Remove the longeron extension fitting in accordance with FIGURE 7.
4. Group 1:
Install a new longeron extension fitting in accordance with FIGURE 8. After installation, finish the
area to match adjacent structure.
5. Group 2:
Install a new longeron extension fitting in accordance with FIGURE 9. After installation, finish the
area to match adjacent structure.
6. Group 3:
Install a new longeron extension fitting in accordance with FIGURE 10. After installation, finish the
area to match adjacent structure.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: December 04, 2012
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BOEING SERVICE BULLETIN 747-53A2860
ALERTALERT

### Page 34

7. Reapply corrosion inhibiting compound, BMS3-35, BMS3-23, Type II or BMS3-29 to the affected
area. Refer to 747-400 AMM 51-24-13 as an accepted procedure.
8. Dejack the airplane. Refer to 747-400 AMM 07-10-00 as an accepted procedure.
9. Install any aft lower lobe cargo compartment sidewall and ceiling linings and insulation blankets
that were removed for internal access to the fasteners in the affected longeron extension fitting.
Refer to 747-400 AMM 25-52-01 and 747-400 AMM 25-52-04 as accepted procedures.
10. Install wing-to-body fairing panels 293C, 293H and 293K (left side) and 294C, 294H and 294K
(right side).
11. Put the airplane back to a serviceable condition.
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: December 04, 2012
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BOEING SERVICE BULLETIN 747-53A2860
ALERTALERT

### Page 35 (OCR)

BOEING SERVICE BULLETIN 747-53A2860
ALERT  ALERT
STA
1480
LONGERON
EXTENSION
FITTING
LEFT SIDE SHOWN,
RIGHT SIDE OPPOSITE
STA
1480
LONGERON
EXTENSION
FITTING
INSPECTION
AREA
FWD
GROUP 1 AND GROUP 2 AIRPLANE SHOWN,
GROUP 3 AIRPLANES SIMILAR
FIGURE 1: LONGERON EXTENSION FITTING INSPECTION
(SHEET 1 OF 2)
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Work - See page 1 for details.  35 of 92

### Page 36

The step numbers shown below agree with the numbers shown in the circle symbols in the figure.
More DataQtyIdentificationNameTaskStep
Surface HFEC for
cracks in accor-
dance with 747 NDT
Part 6, 51-00-00,
Procedure 4 or 23.
--Longeron Extension
Fitting
Inspect1
FIGURE 1: LONGERON EXTENSION FITTING INSPECTION
(SHEET 2 OF 2)
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PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
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BOEING SERVICE BULLETIN 747-53A2860
ALERTALERT

### Page 37 (OCR)

BOEING SERVICE BULLETIN 747-53A2860
ALERT  ALERT
STA
1480
LONGERON
EXTENSION
FITTING
LEFT SIDE SHOWN
RIGHT SIDE OPPOSITE
STA
1480
LONGERON
EXTENSION
FITTING
GROUP 1 AND GROUP 2 AIRPLANE SHOWN,  2167520
GROUP 3 AIRPLANES SIMILAR
FIGURE 2: LONGERON EXTENSION FITTING CRACK REMOVAL (TEMPORARY REPAIR)
(SHEET 1 OF 4)
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Work - See page 1 for details.  37 of 92

### Page 38 (OCR)

BOEING SERVICE BULLETIN 747-53A2860
ALERT  ALERT
TANGENT POINT  - 1.7 D MINIMUM
TYPICAL
CRACK  LONGERON
0.50 MAXIMUM TRIM  EXTENSION
• FITTING
→DO
R 0.50
MINIMUM
B
) TRIM LINE
MAXIMUM REPAIRABLE
CRACK
0.040%  A-A
GROUP 1 AND GROUP 2
TANGENT POINT
- 1.7 D MINIMUM
LONGERON
B  TYPICAL  EXTENSION
0.50 MAXIMUM TRIM  CRACK  ' FITTING
+DO
• R 0.50
MINIMUM
TRIM LINE
MAXIMUM REPAIRABLE
CRACK
B-B  2167524
GROUP 3
FIGURE 2: LONGERON EXTENSION FITTING CRACK REMOVAL (TEMPORARY REPAIR)
(SHEET 2 OF 4)
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Work - See page 1 for details.  38 of 92

### Page 39 (OCR)

BOEING SERVICE BULLETIN 747-53A2860
ALERT  ALERT
STA
1480
LONGERON
- STRAIGHT TAPER  EXTENSION
FITTING
TANGENT POINT  1.10
MINIMUM
(AFTER ONSURANCE
C-C
0.040
2171697
FIGURE 2: LONGERON EXTENSION FITTING CRACK REMOVAL (TEMPORARY REPAIR)
(SHEET 3 OF 4)
Original Issue: December 04, 2012
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Work - See page 1 for details.  39 of 92

### Page 40

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for one side of the airplane.
NOTE: The temporary repair should only be done if any crack is found per FIGURE 1 and is fully contained in
the shaded area of the longeron extension fitting shown.
More DataQtyIdentificationNameTaskStep
(a)--Longeron Extension
Fitting
Cut1
Do a Surface HFEC
of the trimmed edge
of the longeron ex-
tension fitting for
cracks in accor-
dance with 747 NDT
Part 6, 51-00-00,
Procedure 4 or 23 to
ensure that all crack
indications have
been removed. (b)
--Longeron Extension
Fitting
Inspect
(c)--Longeron Extension
Fitting
Cut2
(d)--Longeron Extension
Fitting
Shot Peen
Apply chemical con-
version coating and
two coats of BMS
10-11, Type I primer
to all bare aluminum
surfaces.
--FinishApply
(a) Remove the crack. Trim the longeron extension fitting the minimum necessary to remove the crack, but
do not cut beyond the dimensions shown. Maintain a minimum trim radius of 0.5 inch. Surface finish to
be 63AA or better.
(b) If crack indications are found, trim the longeron extension fitting again the minimum necessary to remove
the crack, but do not cut beyond the dimensions shown. If the cut edge of the longeron extension fitting
has reached the edge of the shaded area shown, the Temporary Repair cannot be accomplished. Do the
Longeron Extension Fitting Replacement shown in Paragraph 3.B., Work Instructions, PART 6.
(c) If no crack indications are found, do an additional 0.040 inch deep trim of the longeron extension fitting
as an insurance cut. Maintain a minimum trim radius of 0.5 inch. Surface finish to be 63AA or better.
(d) Shot or flap peen the trimmed edge of the longeron extension fitting. Refer to SOPM 20-10-03, 747-400
SRM 51-20-06 or 747-400F SRM 51-20-06 as an accepted procedure.
FIGURE 2: LONGERON EXTENSION FITTING CRACK REMOVAL (TEMPORARY REPAIR)
(SHEET 4 OF 4)
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PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: December 04, 2012
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BOEING SERVICE BULLETIN 747-53A2860
ALERTALERT

### Page 41 (OCR)

BOEING SERVICE BULLETIN 747-53A2860
ALERT  ALERT
VIII OUTBOARD WING JACK 5) 67
V INBOARD WING JACK F6  (2) III TAIL JACK
11 BODY JACK 2
VI NOSE JACK
NOSE LANDING GEAR
I BODY JACK (2  3A BODY LANDING
GEAR
IV INBOARD WING JACK (5) 67
VII OUTBOARD WING JACK 5) 6)(
380
370
360  JACKING
AIRPLANE
WEIGHT
(1000 POUNDS)
350
340
10 14  20  30  36 40
(% M.A.C.)
1258 1290.8  1323.6  1356.3  1389.1
(BODY STATION)  2167581
CENTER OF GRAVITY LOCATION
FIGURE 3: JACKING THE AIRPLANE FOR THE PERMANENT REPAIR OR THE PREVENTIVE MODIFICATION
(SHEET 1 OF 3)
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PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.  41 of 92

### Page 42

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for each airplane.
NOTE: Jacking is to be accomplished with flaps retracted. Flaps are not to be operated while the
airplane is on jacks.
1.
2. Jacking is to be accomplished indoors.
3. Airplane center of gravity can be changed with ballast up to a maximum of 10,000 pounds
added forward of Body Station 1480. If ballast is added, make sure that it is added equally
about the airplane centerline. Also make sure that the floor load is less than the allowable
load specified in 747 Weight and Balance Manual D6-13700.
4. Keep the load difference between equivalent left and right side wing jacks less than 10 percent
at all times.
5. The splice straps that connect the inner chords of the upper and lower bulkhead must not be
removed while the airplane is jacked.
CAUTION: KEEP THE LOAD ON WING JACKS IV AND V LESS THAN 30,000 POUNDS EACH AND THE
LOAD ON WING JACKS VII AND VIII LESS THAN 25,000 POUNDS EACH. JACK LOADS LARGER
THAN THESE LIMITS CAN CAUSE STRUCTURAL DAMAGE TO THE WING.
More DataQtyIdentificationNameTaskStep
Into the jacking enve-
lope shown.
--Airplane Weight and
Center of Gravity
Adjust1
Use Jacks I, II and
III only. Refer to
747-400 AMM 07-
10-00 as an accept-
ed procedure.
--AirplaneLift2
Refer to 747-400
AMM 12-15-04 as
an accepted proce-
dure.
--Body Gear Shock StrutDeflate3
(a)--Body Landing GearHold4
(b)--Wing Jack IV, V, VII,
VIII
Apply5
(c)--Wing Jack IV, V, VII,
VIII
Apply6
(d)--Wing Jack IV, V, VII,
VIII
Stop7
FIGURE 3: JACKING THE AIRPLANE FOR THE PERMANENT REPAIR OR THE PREVENTIVE MODIFICATION
(SHEET 2 OF 3)
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Original Issue: December 04, 2012
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BOEING SERVICE BULLETIN 747-53A2860
ALERTALERT

### Page 43

More DataQtyIdentificationNameTaskStep
(a) Make sure that the gear is held in a position between full extension and full compression of the shock
strut so that no load is put on the BS 1480 bulkhead by the weight of the gear. A pedestal can be installed
under the tires to support the gear or the jack height can be adjusted so that the gear is supported by the
wheels on the ground. Alternatively, the body landing gear can be removed.
(b) Load the jacks to 5,000 pounds. Refer to 747-400 AMM 07-10-00 as an accepted procedure.
(c) Increase load gradually. Keep the load difference between equivalent left and right side wing jacks less
than 10 percent at all times. Do not exceed the maximum load limit for these jacks.
(d) Stop increasing the load in Wing Jack IV, V, VII, VIII when the Tail Jack III load is 36,100 - 39,900 pounds.
FIGURE 3: JACKING THE AIRPLANE FOR THE PERMANENT REPAIR OR THE PREVENTIVE MODIFICATION
(SHEET 3 OF 3)
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PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: December 04, 2012
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BOEING SERVICE BULLETIN 747-53A2860
ALERTALERT

### Page 44 (OCR)

BOEING SERVICE BULLETIN 747-53A2860
ALERT  ALERT
STA
1480
LONGERON
EXTENSION
FITTING
LEFT SIDE SHOWN,
RIGHT SIDE OPPOSITE
STA
1480
LONGERON
EXTENSION
FITTING
INSPECTION
AREA
TRIMMED
AREA
TYPICAL LONGERON EXTENSION
FITTED WITH TEMPORARY  REPAIR ACCOMPLISHED  2167591
GROUP 1 AND GROUP 2 AIRPLANE SHOWN,
GROUP 3 AIRPLANE SIMILAR
FIGURE 4: INSPECTION OF LONGERON EXTENSION FITTINGS WITH THE TEMPORARY REPAIR
PREVIOUSLY ACCOMPLISHED
(SHEET 1 OF 2)
Original Issue: December 04, 2012
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Work - See page 1 for details.  44 of 92

### Page 45

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for one side of the airplane.
More DataQtyIdentificationNameTaskStep
Do a Surface HFEC
of the edge of the
longeron extension
fitting, including the
area trimmed as part
of the Temporary
Repair, for cracks in
accordance with 747
NDT Part 6, 51-00-
00, Procedure 4 or
23. (a)
--Longeron Extension
Fitting
Inspect1
(a) If any crack is found, refer to Paragraph 3.B., Work Instructions, PART 3.
FIGURE 4: INSPECTION OF LONGERON EXTENSION FITTINGS WITH THE TEMPORARY REPAIR
PREVIOUSLY ACCOMPLISHED
(SHEET 2 OF 2)
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: December 04, 2012
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45 of 92
BOEING SERVICE BULLETIN 747-53A2860
ALERTALERT

### Page 46 (OCR)

BOEING SERVICE BULLETIN 747-53A2860
ALERT  ALERT
STA
1480
LONGERON
EXTENSION
FITTING
LEFT SIDE SHOWN
RIGHT SIDE OPPOSITE
STA
1480
LONGERON
EXTENSION
FITTING
TRIMMED
FWD  AREA
2167670
FIGURE 5: LONGERON EXTENSION FITTING TEMPORARY REPAIR TRIM PRIOR TO PERMANENT REPAIR
ACCOMPLISHMENT
(SHEET 1 OF 4)
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Work - See page 1 for details.  46 of 92

### Page 47 (OCR)

BOEING SERVICE BULLETIN 747-53A2860
ALERT  ALERT
- 1.7 D MINIMUM
LONGERON
EXTENSION
' FITTING
•DO
R 0.50
MINIMUM
TRIM LINE
FOR MAXIMUM
TEMPORARY
REPAIR
A-A
GROUP 1 AND GROUP 2
- 1.7 D MINIMUM
LONGERON
EXTENSION
' FITTING
LDO
*R 0.50
MINIMUM
B
TRIM LINE
FOR MAXIMUM
TEMPORARY
REPAIR  B-B
GROUP 3  2167673
FIGURE 5: LONGERON EXTENSION FITTING TEMPORARY REPAIR TRIM PRIOR TO PERMANENT REPAIR
ACCOMPLISHMENT
(SHEET 2 OF 4)
Original Issue: December 04, 2012
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PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.  47 of 92

### Page 48 (OCR)

BOEING SERVICE BULLETIN 747-53A2860
ALERT  ALERT
STA
1480
LONGERON
- STRAIGHT TAPER  EXTENSION
FITTING
TANGENT POINT  1.10
MINIMUM  C
(AFTER INSURANCE
CUT)
C-C
TRIM LINE
FOR MAXIMUM
TEMPORARY
REPAIR
0.040
C  2172144
FIGURE 5: LONGERON EXTENSION FITTING TEMPORARY REPAIR TRIM PRIOR TO PERMANENT REPAIR
ACCOMPLISHMENT
(SHEET 3 OF 4)
Original Issue: December 04, 2012
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Work - See page 1 for details.  48 of 92

### Page 49

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for one side of the airplane.
NOTE: These tasks should only be done after the inspection in FIGURE 4 has been done, with no crack
indications found.
More DataQtyIdentificationNameTaskStep
(a)--Longeron Extension
Fitting
Cut1
(b)--Longeron Extension
Fitting
Shot Peen
Apply chemical con-
version coating and
two coats of BMS
10-11, Type I primer
to all bare aluminum
surfaces.
--FinishApply
(a) Do an additional 0.040 inch deep trim of the previous trim done as part of the Temporary Repair as an
insurance cut. Maintain a minimum trim radius of 0.5 inch. Surface finish to be 63AA or better.
(b) Shot or flap peen the trimmed edge of the longeron extension fitting. Refer to SOPM 20-10-03, 747-400
SRM 51-20-06 or 747-400F SRM 51-20-06 as an accepted procedure.
FIGURE 5: LONGERON EXTENSION FITTING TEMPORARY REPAIR TRIM PRIOR TO PERMANENT REPAIR
ACCOMPLISHMENT
(SHEET 4 OF 4)
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PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: December 04, 2012
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BOEING SERVICE BULLETIN 747-53A2860
ALERTALERT

### Page 50 (OCR)

BOEING SERVICE BULLETIN 747-53A2860
ALERT  ALERT
STA
1480
LONGERON
EXTENSION
FITTING
LEFT SIDE SHOWN
RIGHT SIDE OPPOSITE
STA
1480  1 6 LOCATIONS
LONGERON
EXTENSION
FITTING
(1) 6 LOCATIONS  2167696
FIGURE 6: INSPECTION OF THE LONGERON EXTENSION FITTING FOR THE PERMANENT REPAIR OR
PREVENTIVE MODIFICATION
(SHEET 1 OF 2)
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Work - See page 1 for details.  50 of 92

### Page 51

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for one side of the airplane.
More DataQtyIdentificationNameTaskStep
-12-FastenerRemove1
Do an open-hole
HFEC inspection for
cracks at each of
these fastener holes
in accordance with
747 NDT Part 6, 51-
00-00, Procedure 1,
11 or 16.
12-Longeron Extension
Fitting, Skin and under-
lying structure
Inspect
FIGURE 6: INSPECTION OF THE LONGERON EXTENSION FITTING FOR THE PERMANENT REPAIR OR
PREVENTIVE MODIFICATION
(SHEET 2 OF 2)
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ALERTALERT

### Page 52

FIGURE 7: LONGERON EXTENSION FITTING REMOVAL
(SHEET 1 OF 7)
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ALERTALERT

### Page 53 (OCR)

BOEING SERVICE BULLETIN 747-53A2860
ALERT  ALERT
STA
1540
+  +
++++++++++++++++
• STA
1480
++++++++++++++
LONGERON
EXTENSION  + +
FITTING  +
A →
FWD
2167733
FIGURE 7: LONGERON EXTENSION FITTING REMOVAL
(SHEET 2 OF 7)
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### Page 54

FIGURE 7: LONGERON EXTENSION FITTING REMOVAL
(SHEET 3 OF 7)
Export Controlled ECCN: 9E991 - BOEING
PROPRIETARY - Copyright © Unpublished
Work - See page 1 for details.
Original Issue: December 04, 2012
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BOEING SERVICE BULLETIN 747-53A2860
ALERTALERT

### Page 55 (OCR)

BOEING SERVICE BULLETIN 747-53A2860
ALERT  ALERT
UPPER
BULKHEAD
STA  OUTER CHORD
1480
LOWER
BULKHEAD
OUTER CHORD
ONGERON 5) 6
EXTENSION
FITTING
INBD
A-A
2167759
FIGURE 7: LONGERON EXTENSION FITTING REMOVAL
(SHEET 4 OF 7)
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### Page 56

FIGURE 7: LONGERON EXTENSION FITTING REMOVAL
(SHEET 5 OF 7)
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Original Issue: December 04, 2012
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BOEING SERVICE BULLETIN 747-53A2860
ALERTALERT

### Page 57 (OCR)

BOEING SERVICE BULLETIN 747-53A2860
ALERT  ALERT
LONGERON 5) €  EXTENSION
OVERWING  FITTING
LONGERON
TEE CHORD
_ UPPER OUTBOARD
SPLICE FITTING
LOWER OUTBOARD (3  SPLICE ANGLE
3) CHANNEL
TAPERED 3  FILLER
FWD
B-B  2167823
FIGURE 7: LONGERON EXTENSION FITTING REMOVAL
(SHEET 6 OF 7)
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### Page 58

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for one side of the airplane.
More DataQtyIdentificationNameTaskStep
-1-Lower Inboard Splice
Fitting
Remove / Keep1
-2-ShimRemove
-1-Upper Inboard Splice
Angle
Remove / Keep2
-2-ShimRemove
-1-ChannelRemove / Keep3
-1-Tapered FillerRemove / Keep
-1-Lower Outboard Splice
Angle
Remove / Keep
-2-ShimRemove
-1-Upper Outboard Splice
Fitting
Remove / Keep4
-2-ShimRemove
(a)1-Longeron Extension
Fitting
Remove / Keep5
(b)--Fuselage SkinClean6
(a) Remove and keep the longeron extension fitting if the Permanent Repair or Preventive Modification is
being done. Remove and discard the longeron extension fitting if longeron extension fitting replacement
is being done.
(b) Remove remaining sealant and any loose paint from the modification area. Apply chemical conversion
coating and two coats of BMS 10-11, Type I primer to any bare aluminum in the modification area.
FIGURE 7: LONGERON EXTENSION FITTING REMOVAL
(SHEET 7 OF 7)
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BOEING SERVICE BULLETIN 747-53A2860
ALERTALERT

### Page 59

This Figure applies only to: Group 1.
FIGURE 8: LONGERON EXTENSION FITTING INSTALLATION
(SHEET 1 OF 10)
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ALERTALERT

### Page 60 (OCR)

BOEING SERVICE BULLETIN 747-53A2860
ALERT  ALERT
8 LOCATIONS
* = 18)  STA  STA  STA
4 LOCATIONS  1510  1520  1530
18) ATTO  6 LOÇATIONS
5 LOCATIONS
18^7  STA
1540
-+-+-+-+  --+-+-+  - S-33
18 5 11 LOCATIONS  (18) 1 8 9 LOCATIONS  4 LOCATIONS  (18) A
4 LOÇATIONS
(® 8 LOCATIONS  18 18 6 LOCATIONS  1847
6 LOCATIONS  18 ^ 7 5 LOCATIONS
4 LOCATIONS
4 LOCATIONS
STA  1480  18)^  A 5 1500  STA  4 LOCATIONS  18^5
8^6  4 LOCATIONS
18 4 5
18 * 7
33  S-32
18) 1,6 LOCATIONS
1 19 20
LONGERON  - S-33
EXTENSION
FITTING
19 8 LOCATIONS  (18 1107 LOCATIONS
26  (18 5 7 LOCATIONS
8 LOCATIONSA  18  8) 16 LOCATIONS  FWD
2168035
FIGURE 8: LONGERON EXTENSION FITTING INSTALLATION
(SHEET 2 OF 10)
Original Issue: December 04, 2012
Export Controlled ECCN: 9E991 - BOEING  PROPRIETARY - Copyright © Unpublished  747-53A2860
Work - See page 1 for details.  60 of 92

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