# Boeing Alert Service Bulletin MD90-55A014: No revision named

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- Pages: 53
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### Page 1

Commercial 
Airplanes
MD90
Service Bulletin
ALERT
Number: MD90-55A014
Original Issue: June 24, 2010
ATA System: 5531
SUBJECT: STABILIZERS - Vertical Stabilizer - Inspect/Repair Fixed Leading Edge Skin and Front
Spar Cap at Station Zfs=52.267
Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15
CFR 730-774). 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 © 2010 The Boeing Company
Unpublished Work - All Rights Reserved
Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable
subject matter. Boeing also claims copyright in this document as a compilation and/or collective work.
This document includes proprietary information owned by The Boeing Company and/or one or more third parties.
Treatment of the document and the information it contains is governed by contract with Boeing. For more
information, contact The Boeing Company, P.O. Box 3707, Seattle, Washington 98124.
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 the
Boeing livery are all trademarks owned by The Boeing Company; and no trademark license is granted in
connection with this document unless provided in writing by Boeing.
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Table of Contents
Summary ...................................................... 5
1. PLANNING INFORMATION ........................................ 9
A. Effectivity ................................................ 9
1. Airplanes ............................................. 9
2. Spares Affected ........................................ 1 1
B. Concurrent Requirements ...................................... 1 1
C. Reason ................................................ 1 1
D. Description .............................................. 1 1
E. Compliance .............................................. 1 4
F. Approval ............................................... 2 3
G. Manpower .............................................. 2 3
H. Weight and Balance Changes .................................... 2 5
I. Electrical Load Data ......................................... 2 5
J. References .............................................. 2 5
1. Existing Data .......................................... 2 5
2. Data supplied with this Service Bulletin ............................ 2 5
3. Installation Drawings Used in the Preparation of this Service Bulletin ............ 2 5
K. Publications Affected ........................................ 2 5
L. Interchangeability and Intermixability of Parts ........................... 2 6
2. MATERIAL INFORMATION ........................................ 2 7
A. Material - Price and Availability ................................... 2 7
B. Industry Support Information .................................... 2 7
C. Parts Necessary For Each Airplane ................................. 2 7
1. Kits/Parts ............................................ 2 7
2. Parts and Materials Supplied by the Operator ........................ 2 7
3. Parts Modified and Reidentified ................................ 2 7
4. Parts Removed and Not Replaced .............................. 2 7
D. Parts Necessary to Change Spares ................................. 2 7
E. Special Tooling - Price and Availability ............................... 2 7
F. Special Tooling Necessary to do this Service Bulletin ....................... 2 7
3. ACCOMPLISHMENT INSTRUCTIONS .................................. 2 9
A. GENERAL INFORMATION ..................................... 2 9
B. WORK INSTRUCTIONS ....................................... 3 0
APPENDIX A: FLOWCHART - INITIAL INSPECTION AND REPETITIVE INSPECTION .......... 4 1
APPENDIX B: INSPECTION OF VERTICAL STABILIZER FRONT SPAR CAP AT STATION ZFS=52.267 . 44
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Commercial 
Airplanes
MD90
Service Bulletin
ALERT
SummaryNumber: MD90-55A014Original Issue: June 24, 2010
ATA System: 5531
SUBJECT: STABILIZERS - Vertical Stabilizer - Inspect/Repair Fixed Leading Edge Skin and Front
Spar Cap at Station Zfs=52.267
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
One operator reported finding elongated fastener holes at the leading edge of the vertical stabilizer at Station
Zfs=52.267. The affected MD-90 airplane had accrued 15,555 flight-hours and 14,310 landing cycles when the
elongated fastener holes were found during normal maintenance. Furthermore, two MD-80 operators reported
finding a cracked vertical stabilizer skin at Station Zfs=52.267. Subsequent inspection on both affected MD-80
airplanes, revealed a severed front spar cap and a cracked front spar web. The affected MD-80 airplanes had
accrued between 39,749 through 56,212 flight-hours and 32,176 through 44,001 landing cycles when the
cracks/anomalies were found. Cracks were also found on several other MD-80 airplanes, in the vertical stabilizer
front spar cap bolt holes. The MD-90 vertical stabilizer is similar in design and loading as that of the MD-80
vertical stabilizer. Based on service reports and findings, Boeing correlated fastener damage and/or elongated
fastener holes at the leading edge of the vertical stabilizer with structural cracks. Boeing investigation determined
that high loading occurrences, such as, but not limited to, in-flight turbulence can adversely impact the fasteners
and loading at the leading edge of the vertical stabilizer. Inspection will determine condition of the vertical
stabilizer skin. Incorporation of the leading edge repair will minimize the possibility of crack growth. If not corrected,
cracks in the vertical stabilizer leading edge and front spar cap may result in the structure unable to support limit
load, and may lead to the loss of the vertical stabilizer.
ACTION
Refer to Paragraph 1.D., Description.
EFFECTIVITY
MD-90-30 Airplanes. Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplanes.
COMPLIANCE
Refer to Paragraph 1.E., Compliance.
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INDUSTRY SUPPORT INFORMATION
Boeing warranty remedies are not available for the inspection and/or repair procedures given in this service
bulletin.
MANPOWER
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 MD90-55A014
ALERT  ALERT
INSPECT/REPAIR FIXED LEADING
EDGE SKIN AND FRONT SPAR CAP
AT STATION ZFS=52.267
1955969
Original Issue: June 24, 2010
MD90-55A014
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Commercial 
Airplanes
MD90
Service Bulletin
ALERT
Number: MD90-55A014
Original Issue: June 24, 2010
ATA System: 5531
SUBJECT: STABILIZERS - Vertical Stabilizer - Inspect/Repair Fixed Leading Edge Skin and Front
Spar Cap at Station Zfs=52.267
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 for the airplanes shown below.
DESCRIPTIONCONFIGURATIONGROUP
MD-90-30 Airplanes-1
Airplane Models:
MD-90-30
GroupFuselage Num-
ber
12094 - 2100
12115
12117
12120
12122 - 2123
12125 - 2126
12129
12131
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GroupFuselage Num-
ber
12133
12136
12138
12140 - 2144
12146 - 2147
12149 - 2150
12153 - 2154
12156 - 2159
12161 - 2166
12169 - 2171
12173
12175
12177
12179
12181
12184
12186
12190 - 2191
12193 - 2195
12197 - 2198
12200
12202 - 2203
12205
12207
12209 - 2213
12215 - 2217
12219 - 2233
12235 - 2237
12240
12243
12245
12248
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GroupFuselage Num-
ber
12250 - 2251
12253
12255 - 2263
12288 - 2290
14001 - 4002
2. Spares Affected
None.
B. Concurrent Requirements
None.
C. Reason
One operator reported finding elongated fastener holes at the leading edge of the vertical stabilizer at
Station Zfs=52.267. The affected MD-90 airplane had accrued 15,555 flight-hours and 14,310 landing
cycles when the elongated fastener holes were found during normal maintenance. Furthermore, two
MD-80 operators reported finding a cracked vertical stabilizer skin at Station Zfs=52.267. Subsequent
inspection on both affected MD-80 airplanes, revealed a severed front spar cap and a cracked front
spar web. The affected MD-80 airplanes had accrued between 39,749 through 56,212 flight-hours and
32,176 through 44,001 landing cycles when the cracks/anomalies were found. Cracks were also found
on several other MD-80 airplanes, in the vertical stabilizer front spar cap bolt holes. The MD-90 vertical
stabilizer is similar in design and loading as that of the MD-80 vertical stabilizer. Based on service
reports and findings, Boeing correlated fastener damage and/or elongated fastener holes at the leading
edge of the vertical stabilizer with structural cracks. Boeing investigation determined that high loading
occurrences, such as, but not limited to, in-flight turbulence can adversely impact the fasteners and
loading at the leading edge of the vertical stabilizer. Inspection will determine condition of the vertical
stabilizer skin. Incorporation of the leading edge repair will minimize the possibility of crack growth. If
not corrected, cracks in the vertical stabilizer leading edge and front spar cap may result in the structure
unable to support limit load, and may lead to the loss of the vertical stabilizer.
D. Description
This service bulletin provides instructions to do an initial inspection and repetitive inspections of the
vertical stabilizer leading edge structure at the splice at Station Zfs=52.267, and the vertical stabilizer
front spar cap forward flanges and either the aft flanges or side skins, as follows:
NOTE: Refer to APPENDIX A: FLOWCHART - INITIAL INSPECTION AND REPETITIVE INSPECTION,
as a supplement to Paragraph 1.D., Description.
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PART A - INITIAL INSPECTION:
1. Removes two rows of fasteners above the splice and two rows of fasteners below the splice at
Station Zfs=52.267.
2. Does a detailed inspection for "distress" in, and "existing repairs" to, the vertical stabilizer leading
edge structure at the splice at Station Zfs=52.267.
NOTE: "Distress" is defined as deformed holes, elongated holes, oversized holes or cracks in
the leading edge skin and splice.
"Existing Repairs" are bushings, washers or reinforcing repairs to the leading edge.
3. Based on inspection results, does as follows:
CONDITION 1 (Leading Edge is Not Distressed and No Existing Repair Found)
a. Does an inspection for cracking on the left and right vertical stabilizer front spar cap forward
flanges and either the aft flanges or side skins at Station Zfs=52.267.
b. Based on inspection results, does as follows:
CONDITION 1A (No Crack Found)
(1) Puts the airplane back to a serviceable condition.
CONDITION 1B (Any Crack Found)
(1) Does an evaluation/verification to confirm all crack indications.
(2) Contacts Boeing for repair of all cracking and does the repair in accordance with Boeing's
instructions.
(3) Puts the airplane back to a serviceable condition.
CONDITION 2 (Leading Edge is Distressed)
a. Does an inspection for cracking on the left and right vertical stabilizer front spar cap forward
flanges and either the aft flanges or side skins at Station Zfs=52.267.
b. Based on inspection results, does as follows:
CONDITION 2A (No Crack Found)
(1) Does leading edge repair.
(2) Puts the airplane back to a serviceable condition.
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CONDITION 2B (Any Crack Found)
(1) Does leading edge repair.
(2) Does an evaluation/verification to confirm all crack indications.
(3) Contacts Boeing for repair of all cracking and does the repair in accordance with Boeing's
instructions.
(4) Puts the airplane back to a serviceable condition.
CONDITION 3 (Leading Edge Existing Repair Found)
a. Does an inspection for cracking on the left and right vertical stabilizer front spar cap forward
flanges and either the aft flanges or side skins at Station Zfs=52.267.
b. Based on inspection results, does as follows:
CONDITION 3A (No Crack Found)
(1) Puts the airplane back to a serviceable condition.
CONDITION 3B (Any Crack Found)
(1) Does an evaluation/verification to confirm all crack indications.
(2) Contacts Boeing for repair of all cracking and does the repair in accordance with Boeing's
instructions.
(3) Puts the airplane back to a serviceable condition.
PART B - REPETITIVE INSPECTION:
1. Inspection - Vertical Stabilizer Leading Edge:
a. Does a detailed inspection of the vertical stabilizer leading edge at the splice at Station
Zfs=52.267 (fasteners not removed) for indications of loose fasteners and missing fasteners.
b. Based on inspection results, does as follows:
CONDITION 4 (No Loose Leading Edge Fasteners and No Missing Leading Edge
Fasteners)
(1) Does repetitive detailed inspection of the vertical stabilizer leading edge at the splice at
Station Zfs=52.267 (fasteners not removed) for indications of loose fasteners and missing
fasteners.
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CONDITION 5 (Loose Leading Edge Fasteners or Missing Leading Edge Fasteners)
(1) Does leading edge repair.
(2) Does repetitive detailed inspection of the vertical stabilizer leading edge at the splice at
Station Zfs=52.267 (fasteners not removed) for indications of loose fasteners and missing
fasteners.
2. Inspection - Vertical Stabilizer Front Spar Cap Forward Flanges and either the Aft Flanges or Side
Skins:
a. Does an inspection for cracking on the left and right vertical stabilizer front spar cap forward
flanges and either the aft flanges or side skins at Station Zfs=52.267.
b. Based on inspection results, does as follows:
CONDITION 6 (No Crack Found)
(1) Does repetitive inspection for cracks on the left and right vertical stabilizer front spar cap
forward flanges and either the aft flanges or side skins at Station Zfs=52.267.
CONDITION 7 (Any Crack Found)
(1) Does an evaluation/verification to confirm all crack indications.
(2) Contacts Boeing for repair of all cracking and does the repair in accordance with Boeing's
instructions.
3. Puts the airplane back to a serviceable condition.
The work in this service bulletin is done in the maintenance zone(s) given below.
Affected Maintenance Zones
ZoneModel
371, 373MD-90-30
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.
NOTE: Refer to APPENDIX A: FLOWCHART - INITIAL INSPECTION AND REPETITIVE INSPECTION,
as a supplement to Paragraph 1.E., Compliance.
NOTE: "Distress" is defined as deformed holes, elongated holes, oversized holes or cracks in the
leading edge skin and splice.
"Existing Repairs" are bushings, washers or reinforcing repairs to the leading edge.
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Table 1: PART A - Initial Inspection: Fixed Leading Edge Skin and Front Spar Cap at Station Zfs=52.267
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
-Within 4,100 flight
cycles after the
original issue date
on this service bul-
letin.
Do a detailed inspection for "distress" in, and
"existing repairs" to, the vertical stabilizer
leading edge structure at the splice at Station
Zfs=52.267 in accordance with Paragraph
3.B., Work Instructions.
All Airplanes
-Before further
flight.
Do an inspection for cracking on the left and
right vertical stabilizer front spar cap forward
flanges and either the aft flanges or side
skins at Station Zfs=52.267, using one of the
options as follows:
CONDITION 1
(Leading Edge is Not
Distressed and No Ex-
isting Repair Found)
--OPTION 1:
Do an open hole Eddy Current, High Fre-
quency (ETHF) inspection of the left and
right vertical stabilizer front spar cap forward
flanges in accordance with Paragraph 3.B.,
Work Instructions.
AND
Do a Radiographic Testing (RT) inspection
of the left and right vertical stabilizer front
spar cap aft flanges in accordance with
Paragraph 3.B., Work Instructions.
OR
--OPTION 2:
Do an open hole ETHF inspection of the left
and right vertical stabilizer front spar cap
forward flanges in accordance with Para-
graph 3.B., Work Instructions.
AND
Do an ETHF surface inspection of the left
and right side skins at the vertical stabilizer
front spar cap aft flanges in accordance with
Paragraph 3.B., Work Instructions.
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Table 1: PART A - Initial Inspection: Fixed Leading Edge Skin and Front Spar Cap at Station Zfs=52.267
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
-In Accordance With
Table 2: PART B -
Repetitive Inspec-
tion: Fixed Leading
Edge Skin at Sta-
tion Zfs=52.267
Do repetitive inspections of the vertical stabi-
lizer leading edge structure at the splice at
Station Zfs=52.267 in accordance with
Paragraph 3.B., Work Instructions.
CONDITION 1A
(No Crack Found dur-
ing either Option 1 or
Option 2 Inspection)
AND
-In Accordance With
Table 3: PART B -
Repetitive Inspec-
tion: Front Spar
Cap at Station
Zfs=52.267
Do repetitive inspections of the left and right
vertical stabilizer front spar cap forward
flanges and either the aft flanges or side
skins at Station Zfs=52.267 in accordance
with Paragraph 3.B., Work Instructions.
-Before further
flight.
Do an evaluation/verification to confirm all
crack indications in accordance with Para-
graph 3.B., Work Instructions.
CONDITION 1B
(Any Crack Found dur-
ing either Option 1 or
Option 2 Inspection)
-Before further
flight.
Contact Boeing for repair of all cracking and
do the repair in accordance with Boeing's
instructions.
CONDITION 1B
(Any confirmed crack
indication)
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Table 1: PART A - Initial Inspection: Fixed Leading Edge Skin and Front Spar Cap at Station Zfs=52.267
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
-Before further
flight.
Do an inspection for cracking on the left and
right vertical stabilizer front spar cap forward
flanges and either the aft flanges or side
skins at Station Zfs=52.267, using one of the
options as follows:
CONDITION 2
(Leading Edge is Dis-
tressed)
--OPTION 1:
Do an open hole ETHF inspection of the left
and right vertical stabilizer front spar cap
forward flanges in accordance with Para-
graph 3.B., Work Instructions.
AND
Do an RT inspection of the left and right
vertical stabilizer front spar cap aft flanges
in accordance with Paragraph 3.B., Work
Instructions.
OR
--OPTION 2:
Do an open hole ETHF inspection of the left
and right vertical stabilizer front spar cap
forward flanges in accordance with Para-
graph 3.B., Work Instructions.
AND
Do an ETHF surface inspection of the left
and right side skins at the vertical stabilizer
front spar cap aft flanges in accordance with
Paragraph 3.B., Work Instructions.
-Before further
flight.
Do leading edge repair in accordance with
Paragraph 3.B., Work Instructions.
CONDITION 2A
(No Crack Found dur-
ing either Option 1 or
Option 2 Inspection) AND
-In Accordance With
Table 2: PART B -
Repetitive Inspec-
tion: Fixed Leading
Edge Skin at Sta-
tion Zfs=52.267
Do repetitive inspections of the vertical stabi-
lizer leading edge structure at the splice at
Station Zfs=52.267 in accordance with
Paragraph 3.B., Work Instructions.
AND
-In Accordance With
Table 3: PART B -
Repetitive Inspec-
tion: Front Spar
Cap at Station
Zfs=52.267
Do repetitive inspections of the left and right
vertical stabilizer front spar cap forward
flanges and either the aft flanges or side
skins at Station Zfs=52.267 in accordance
with Paragraph 3.B., Work Instructions.
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### Page 18

Table 1: PART A - Initial Inspection: Fixed Leading Edge Skin and Front Spar Cap at Station Zfs=52.267
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
-Before further
flight.
Do leading edge repair in accordance with
Paragraph 3.B., Work Instructions.
CONDITION 2B
(Any Crack Found dur-
ing either Option 1 or
Option 2 Inspection) AND
-Before further
flight.
Do an evaluation/verification to confirm all
crack indications in accordance with Para-
graph 3.B., Work Instructions.
AND
-Before further
flight.
Contact Boeing for repair of all cracking and
do the repair in accordance with Boeing's
instructions.
CONDITION 2B
(Any confirmed crack
indication)
-Before further
flight.
Do an inspection for cracking on the left and
right vertical stabilizer front spar cap forward
flanges and either the aft flanges or side
skins at Station Zfs=52.267, using one of the
options as follows:
CONDITION 3
(Leading Edge Existing
Repair Found)
--OPTION 1:
Do an open hole ETHF inspection of the left
and right vertical stabilizer front spar cap
forward flanges in accordance with Para-
graph 3.B., Work Instructions.
AND
Do an RT inspection of the left and right
vertical stabilizer front spar cap aft flanges
in accordance with Paragraph 3.B., Work
Instructions.
OR
--OPTION 2:
Do an open hole ETHF inspection of the left
and right vertical stabilizer front spar cap
forward flanges in accordance with Para-
graph 3.B., Work Instructions.
AND
Do an ETHF surface inspection of the left
and right side skins at the vertical stabilizer
front spar cap aft flanges in accordance with
Paragraph 3.B., Work Instructions.
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### Page 19

Table 1: PART A - Initial Inspection: Fixed Leading Edge Skin and Front Spar Cap at Station Zfs=52.267
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
-In Accordance With
Table 2: PART B -
Repetitive Inspec-
tion: Fixed Leading
Edge Skin at Sta-
tion Zfs=52.267
Do repetitive inspections of the vertical stabi-
lizer leading edge structure at the splice at
Station Zfs=52.267 in accordance with
Paragraph 3.B., Work Instructions.
CONDITION 3A
(No Crack Found dur-
ing either Option 1 or
Option 2 Inspection)
AND
-In Accordance With
Table 3: PART B -
Repetitive Inspec-
tion: Front Spar
Cap at Station
Zfs=52.267
Do repetitive inspections of the left and right
vertical stabilizer front spar cap forward
flanges and either the aft flanges or side
skins at Station Zfs=52.267 in accordance
with Paragraph 3.B., Work Instructions.
-Before further
flight.
Do an evaluation/verification to confirm all
crack indications in accordance with Para-
graph 3.B., Work Instructions.
CONDITION 3B
(Any Crack Found dur-
ing either Option 1 or
Option 2 Inspection)
-Before further
flight.
Contact Boeing for repair of all cracking and
do the repair in accordance with Boeing's
instructions.
CONDITION 3B
(Any confirmed crack
indication)
Table 2: PART B - Repetitive Inspection: Fixed Leading Edge Skin at Station Zfs=52.267
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
-Within 4,400 flight
cycles after doing
the initial inspec-
tion.
Do a detailed inspection of the vertical stabi-
lizer leading edge structure at the splice at
Station Zfs=52.267 for indications of loose
fasteners and missing fasteners in accor-
dance with Paragraph 3.B., Work Instruc-
tions.
Airplanes from CONDI-
TION 1A or 2A or 3A of
Table 1: PART A - Ini-
tial Inspection on which
the OPTION 1 inspec-
tions were done.
-Within 3,000 flight
cycles after doing
the initial inspec-
tion.
Do a detailed inspection of the vertical stabi-
lizer leading edge structure at the splice at
Station Zfs=52.267 for indications of loose
fasteners and missing fasteners in accor-
dance with Paragraph 3.B., Work Instruc-
tions.
Airplanes from CONDI-
TION 1A or 2A or 3A of
Table 1: PART A - Ini-
tial Inspection on which
the OPTION 2 inspec-
tions were done.
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Table 2: PART B - Repetitive Inspection: Fixed Leading Edge Skin at Station Zfs=52.267
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
4,400 flight cycles
(a)
Within 4,400 flight
cycles after doing
the detailed inspec-
tion.
Do repetitive detailed inspection of the verti-
cal stabilizer leading edge structure at the
splice at Station Zfs=52.267 for indications
of loose fasteners and missing fasteners in
accordance with Paragraph 3.B., Work In-
structions.
CONDITION 4
(No Loose Leading
Edge Fasteners and No
Missing Leading Edge
Fasteners) for airplanes
on which the prior in-
spection of the front
spar cap was done us-
ing OPTION 1.
3,000 flight cycles
(a)
Within 3,000 flight
cycles after doing
the detailed inspec-
tion.
Do repetitive detailed inspection of the verti-
cal stabilizer leading edge structure at the
splice at Station Zfs=52.267 for indications
of loose fasteners and missing fasteners in
accordance with Paragraph 3.B., Work In-
structions.
CONDITION 4
(No Loose Leading
Edge Fasteners and No
Missing Leading Edge
Fasteners) for airplanes
on which the prior in-
spection of the front
spar cap was done us-
ing OPTION 2.
-Before further
flight.
Do leading edge repair in accordance with
Paragraph 3.B., Work Instructions.
CONDITION 5
(Loose Leading Edge
Fasteners or Missing
Leading Edge Fasten-
ers) for airplanes on
which the prior inspec-
tion of the front spar
cap was done using
OPTION 1.
AND
4,400 flight cycles
(a)
Within 4,400 flight
cycles after doing
the detailed inspec-
tion.
Do repetitive detailed inspection of the verti-
cal stabilizer leading edge structure at the
splice at Station Zfs=52.267 for indications
of loose fasteners and missing fasteners in
accordance with Paragraph 3.B., Work In-
structions.
-Before further
flight.
Do leading edge repair in accordance with
Paragraph 3.B., Work Instructions.
CONDITION 5
(Loose Leading Edge
Fasteners or Missing
Leading Edge Fasten-
ers) for airplanes on
which the prior inspec-
tion of the front spar
cap was done using
OPTION 2.
AND
3,000 flight cycles
(a)
Within 3,000 flight
cycles after doing
the detailed inspec-
tion.
Do repetitive detailed inspection of the verti-
cal stabilizer leading edge structure at the
splice at Station Zfs=52.267 for indications
of loose fasteners and missing fasteners in
accordance with Paragraph 3.B., Work In-
structions.
(a) Changing from one inspection option to another option is acceptable, provided the repeat interval require-
ment is first complied with, before changing options.
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Table 3: PART B - Repetitive Inspection: Front Spar Cap at Station Zfs=52.267
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
-Within 4,400 flight
cycles after doing
the initial inspec-
tion.
Do an inspection for cracking on the left and
right vertical stabilizer front spar cap forward
flanges and either the aft flanges or side
skins at Station Zfs=52.267, using one of the
options as follows:
Airplanes from CONDI-
TION 1A or 2A or 3A of
Table 1: PART A - Ini-
tial Inspection on which
the OPTION 1 inspec-
tions were done. --OPTION 1:
Do an open hole ETHF inspection of the left
and right vertical stabilizer front spar cap
forward flanges in accordance with Para-
graph 3.B., Work Instructions.
AND
Do an RT inspection of the left and right
vertical stabilizer front spar cap aft flanges
in accordance with Paragraph 3.B., Work
Instructions.
OR
--OPTION 2:
Do an open hole ETHF inspection of the left
and right vertical stabilizer front spar cap
forward flanges in accordance with Para-
graph 3.B., Work Instructions.
AND
Do an ETHF surface inspection of the left
and right side skins at the vertical stabilizer
front spar cap aft flanges in accordance with
Paragraph 3.B., Work Instructions.
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Table 3: PART B - Repetitive Inspection: Front Spar Cap at Station Zfs=52.267
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
-Within 3,000 flight
cycles after doing
the initial inspec-
tion.
Do an inspection for cracking on the left and
right vertical stabilizer front spar cap forward
flanges and either the aft flanges or side
skins at Station Zfs=52.267, using one of the
options as follows:
Airplanes from CONDI-
TION 1A or 2A or 3A of
Table 1: PART A - Ini-
tial Inspection on which
the OPTION 2 inspec-
tions were done. --OPTION 1:
Do an open hole ETHF inspection of the left
and right vertical stabilizer front spar cap
forward flanges in accordance with Para-
graph 3.B., Work Instructions.
AND
Do an RT inspection of the left and right
vertical stabilizer front spar cap aft flanges
in accordance with Paragraph 3.B., Work
Instructions.
OR
--OPTION 2:
Do an open hole ETHF inspection of the left
and right vertical stabilizer front spar cap
forward flanges in accordance with Para-
graph 3.B., Work Instructions.
AND
Do an ETHF surface inspection of the left
and right side skins at the vertical stabilizer
front spar cap aft flanges in accordance with
Paragraph 3.B., Work Instructions.
4,400 flight cycles
(a)
Within 4,400 flight
cycles after doing
the inspection.
Do repetitive inspections of the left and right
vertical stabilizer front spar cap forward
flanges and either the aft flanges or side
skins at Station Zfs=52.267 in accordance
with Paragraph 3.B., Work Instructions.
CONDITION 6
(No Crack Found) for
airplanes on which the
prior inspection of the
front spar cap was
done using OPTION 1.
3,000 flight cycles
(a)
Within 3,000 flight
cycles after doing
the inspection.
Do repetitive inspections of the left and right
vertical stabilizer front spar cap forward
flanges and either the aft flanges or side
skins at Station Zfs=52.267 in accordance
with Paragraph 3.B., Work Instructions.
CONDITION 6
(No Crack Found) for
airplanes on which the
prior inspection of the
front spar cap was
done using OPTION 2.
-Before further
flight.
Do an evaluation/verification to confirm all
crack indications in accordance with Para-
graph 3.B., Work Instructions.
CONDITION 7
(Any Crack Found dur-
ing either Option 1 or
Option 2 Inspection)
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Table 3: PART B - Repetitive Inspection: Front Spar Cap at Station Zfs=52.267
Repeat Interval
(Not to Exceed)
Compliance TimeActionCondition
-Before further
flight.
Contact Boeing for repair of all cracking and
do the repair in accordance with Boeing's
instructions.
CONDITION 7
(Any confirmed crack
indication)
(a) Changing from one inspection option to another option is acceptable, provided the repeat interval require-
ment is first complied with, before changing options.
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 the inspection/change/repair 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: PART A - Initial Inspection: Fixed Leading Edge Skin and Front Spar Cap at Station
Zfs=52.267
Elapsed HoursTask HoursNumber of PersonsTask
1.51.51Remove Fasteners -
Fixed Leading Edge
1.01.01Inspect - Fixed Lead-
ing Edge
1.01.01Remove Fasteners -
Front Spar Cap For-
ward Flange
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Table 1: PART A - Initial Inspection: Fixed Leading Edge Skin and Front Spar Cap at Station
Zfs=52.267
Elapsed HoursTask HoursNumber of PersonsTask
1.01.01Inspect - Front Spar
Cap Forward Flange
1.51.51Install Fasteners -
Front Spar Cap For-
ward Flange
2.02.01Inspect - Front Spar
Cap Aft Flange
2.02.01Install Fasteners -
Fixed Leading Edge
10.010.0TOTAL FOR EACH AIRPLANE
(a) (b)
(a) Inspection hours given are for each airplane.
(b) Task hours required for repairs are not included and are to be determined by
the operator based on inspection results.
Table 2: PART B - Repetitive Inspection: Fixed Leading Edge Skin and Front Spar Cap at
Station Zfs=52.267
Elapsed HoursTask HoursNumber of PersonsTask
1.01.01Inspect - Fixed Lead-
ing Edge
1.01.01Remove Fasteners -
Front Spar Cap For-
ward Flange
1.01.01Inspect - Front Spar
Cap Forward Flange
1.51.51Install Fasteners -
Front Spar Cap For-
ward Flange
2.02.01Inspect - Front Spar
Cap Aft Flange
6.56.5TOTAL FOR EACH AIRPLANE
(a) (b)
(a) Inspection hours given are for each airplane.
(b) Task hours required for repairs are not included and are to be determined by
the operator based on inspection results.
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H. Weight and Balance Changes
Weight and balance changes affected by incorporation of this service bulletin are contingent upon the
changes to each particular airplane. Weight data is to be computed by the operator by weighing parts
removed and parts installed during this change. Necessary revisions should be made to the appropriate
airplane weight and balance report.
I. Electrical Load Data
Not changed.
J. References
1. Existing Data
a. Non-Destructive Test Standard Practices Manual (NDTSPM), 02-00-07, 06-00-07,
06-10-01.001, 06-10-01.003, Part 01-00-03, Part 02-00-03, Part 02-00-04, Part 06-00-03,
Part 06-00-04.
b. MD90 Structural Repair Manual (SRM) 55-30-05.
2. Data supplied with this Service Bulletin
None.
3. Installation Drawings Used in the Preparation of this Service Bulletin
ChangeTitleDocument Number
AREPAIR-FIXED LEADING EDGE
SKIN, ZFS=52.267, VERTICAL STA-
BILIZER
SG09550004
DASTRUCTURE ASSY-VERT STAB5912123
YLEADING EDGE INSTL-VERTICAL
STABILIZER
5930609
FCAP-VERT STAB FRONT SPAR5911394
ADSPAR ASSY-VERT STAB, FRONT9911833
These drawings were used to prepare this service bulletin. These drawings are not necessary to
make the specified changes, and are not supplied with this service bulletin. These drawings may
not be applicable to all airplane configurations or operators.
K. Publications Affected
1. Publications:
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Chapter-SectionPublication
MD90 SRM 55-30-05Structural Repair Manual
2. Damage Tolerance Based Structural Inspections:
Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue
Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the
Maintenance Program. This service bulletin affects FCS. DTI requirements for the structure affected
are contained in Paragraph 1.E., Compliance of this service bulletin.
L. Interchangeability and Intermixability of Parts
Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts.
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2.    MATERIAL INFORMATION
A. Material - Price and Availability
None.
B. Industry Support Information
Boeing warranty remedies are not available for the inspection and/or repair procedures given in this
service bulletin.
C. Parts Necessary For Each Airplane
1. Kits/Parts
Based on inspection results, refer to Service General Repair Drawing SG09550004, for repair
parts necessary for each airplane.
2. Parts and Materials Supplied by the Operator
Based on inspection results, refer to Service General Repair Drawing SG09550004, for operator
supplied parts and materials necessary to do the required repairs.
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
Inspection equipment required to accomplish this service bulletin are listed in APPENDIX B and in the
Non-Destructive Test Standard Practices Manual ( NDTSPM ) and are to be procured from operator’s
stock or sources indicated.
F. Special Tooling Necessary to do this Service Bulletin
No special tools or equipment are necessary to do the change in this service bulletin. But, maintenance
and overhaul tools in the manuals given in Paragraph 1.J., References, can be necessary. Examine
operator tool supply to make sure all necessary tools are available.
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### Page 29

3.    ACCOMPLISHMENT INSTRUCTIONS
A. GENERAL INFORMATION
WARNING: IF ELECTRICAL POWER IS APPLIED TO THE AIRPLANE, MAKE SURE YOU OBEY
ALL PRECAUTIONS WHILE YOU DO WORK. IF YOU DO NOT OBEY THE
PRECAUTIONS, DEATH OR INJURY TO PERSONS, AND DAMAGE TO THE AIRPLANE
CAN OCCUR.
CAUTION: ELECTRICALLY GROUND THE AIRPLANE. THIS WILL HELP TO PREVENT DAMAGE
TO THE AIRPLANE OR EQUIPMENT.
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. The instructions identified in Paragraph 3.B., Work Instructions, and the Figure(s)
give the recommended sequence of steps. The sequence of steps to do this service
bulletin can be changed.
2. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for
definition of the acronyms.
3. Equivalent parts are listed in the AEPL, Drawing 7595071.
4. Use the approved fastener substitutions and process material substitutions, in
accordance with MD90 SRM 51.
5. Obey all of the warnings and cautions given in the specified manual sections.
6. The inspection area of the vertical stabilizer leading edge structure is two rows of
fasteners above the splice and two rows of fasteners below the splice at Station
Zfs=52.267.
7. "Distress" in the vertical stabilizer leading edge structure at the splice at Station
Zfs=52.267 is defined as deformed holes, elongated holes, oversized holes or cracks
in the leading edge skin and splice.
8. "Existing Repairs" to the vertical stabilizer leading edge structure at the splice at
Station Zfs=52.267 are bushings, washers or reinforcing repairs to the leading edge.
9. "Breakaway torque" is defined as the torque required to overcome static friction when
100 percent of the locking feature is engaged and the fastener is unseated. Breakaway
torque can be prefixed with a "maximum" or "minimum", and can be measured in
either a loosening or tightening direction. Check for proper minimum breakaway
torque. The minimum breakaway torque value for 1/4 inch diameter fasteners is 5.0
inch-pounds. The minimum breakaway torque value for 5/16 inch diameter fasteners
is 7.0 inch-pounds.
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10. The inspection area of the left and right vertical stabilizer front spar cap forward
flanges and either the aft flanges or side skins is defined as 12.50 inches +/- 0.25
inch above the leading edge skin splice and 12.50 inches +/- 0.25 inch below the
leading edge skin splice at Station Zfs=52.267.
11. Where the work instructions include installation of a kept part, a new or serviceable
part with the same part number can be installed as an alternative to the same part.
The removed part can be discarded if a new part or serviceable part is installed.
12. Refer to APPENDIX A: FLOWCHART - INITIAL INSPECTION AND REPETITIVE
INSPECTION which describes the initial inspection and repetitive inspection
requirements and can be used as a supplement to Paragraph 3.B., Work Instructions.
13. Refer to APPENDIX B: INSPECTION OF VERTICAL STABILIZER FRONT SPAR
CAP AT STATION ZFS=52.267, for the inspection procedures and requirements in
accordance with Paragraph 3.B., Work Instructions.
14. 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.
15. 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.
B. WORK INSTRUCTIONS
PART A - INITIAL INSPECTION:
1. Do an initial inspection of the vertical stabilizer leading edge structure at the splice at Station
Zfs=52.267 as follows:
a. Remove and keep two rows of fasteners above the splice and two rows of fasteners below
the splice at Station Zfs=52.267.
NOTE: Remove fasteners one row at a time.
b. Do a detailed inspection for "distress" in, and "existing repairs" to, the vertical stabilizer leading
edge structure at the splice at Station Zfs=52.267.
NOTE: "Distress" is defined as deformed holes, elongated holes, oversized holes or cracks
in the leading edge skin and splice.
"Existing Repairs" are bushings, washers or reinforcing repairs to the leading edge.
2. Based on inspection results, do as follows:
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CONDITION 1 (Leading Edge is Not Distressed and No Existing Repair Found)
a. Do an inspection for cracking on the left and right vertical stabilizer front spar cap forward
flanges and either the aft flanges or side skins at Station Zfs=52.267 in accordance with
APPENDIX B, using one of the options as follows:
NOTE: The inspection area is defined as 12.50 inches +/- 0.25 inch above the leading edge
skin splice and 12.50 inches +/- 0.25 inch below the leading edge skin splice at
Station Zfs=52.267.
OPTION 1:
(1) Do an Eddy Current, High Frequency (ETHF) inspection of the left and right vertical
stabilizer front spar cap forward flanges as follows:
(a) Remove and keep fasteners common to the left and right vertical stabilizer front spar
cap forward flanges, above and below the leading edge skin splice at Station
Zfs=52.267.
(b) Do an open hole ETHF inspection of the left and right vertical stabilizer front spar
cap forward flanges at the fastener holes above and below the leading edge skin
splice at Station Zfs=52.267 in accordance with the inspection procedure in
APPENDIX B, Inspection Sequence 1.
(2) Do a Radiographic Testing (RT) inspection of the left and right vertical stabilizer front
spar cap aft flanges in accordance with the inspection procedure in APPENDIX B,
Inspection Sequence 2 - Option 1.
OPTION 2:
(1) Do an ETHF inspection of the left and right vertical stabilizer front spar cap forward flanges
as follows:
(a) Remove and keep fasteners common to the left and right vertical stabilizer front spar
cap forward flanges, above and below the leading edge skin splice at Station
Zfs=52.267.
(b) Do an open hole ETHF inspection of the left and right vertical stabilizer front spar
cap forward flanges at the fastener holes above and below the leading edge skin
splice at Station Zfs=52.267 in accordance with the inspection procedure in
APPENDIX B, Inspection Sequence 1.
(2) Do an ETHF surface inspection of the side skin at the left and right vertical stabilizer front
spar cap aft flanges in accordance with the inspection procedure in APPENDIX B,
Inspection Sequence 2 - Option 2.
b. Based on inspection results, do as follows:
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CONDITION 1A (No Crack Found during either Option 1 or Option 2 Inspection)
(1) Install kept fasteners common to the left and right vertical stabilizer front spar cap forward
flanges.
(2) Install kept leading edge fasteners.
CONDITION 1B (Any Crack Found during either Option 1 or Option 2 Inspection)
(1) Crack Found on the Vertical Stabilizer Front Spar Cap Forward Flange
(a) Remove and keep nut plate gang channel on the vertical stabilizer front spar cap
forward flange where the crack indication was found.
(b) Do an evaluation/verification to confirm any crack indication found on the vertical
stabilizer front spar cap forward flange. Refer to NDTSPM 06-00-07 for applicable
Crack/Defect Evaluation/Verification.
1) Crack Indication Not Confirmed
a) Install kept nut plate gang channel on the vertical stabilizer front spar cap
forward flange.
b) Install kept fasteners common to the left and right vertical stabilizer front
spar cap forward flanges.
2) Crack Indication Confirmed
a) Contact Boeing for repair of the vertical stabilizer front spar cap forward
flange and do the repair in accordance with Boeing's instructions.
(2) Crack Found on the Vertical Stabilizer Side Skin or Front Spar Cap Aft Flange
(a) Do an evaluation/verification to confirm any crack indication found on the vertical
stabilizer side skins. Refer to NDTSPM 06-00-07 for applicable Crack/Defect
Evaluation/Verification.
1) Crack Indication Not Confirmed
a) Install kept leading edge fasteners.
2) Crack Indication Confirmed
a) Contact Boeing for repair of the vertical stabilizer side skins and do the
repair in accordance with Boeing's instructions.
(b) Do an evaluation/verification to confirm any crack indication found on the front spar
cap aft flange. Refer to NDTSPM 02-00-07 for applicable Crack/Defect
Evaluation/Verification.
1) Crack Indication Not Confirmed
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a) Install kept leading edge fasteners.
2) Crack Indication Confirmed
a) Contact Boeing for repair of the vertical stabilizer front spar cap aft flange
and do the repair in accordance with Boeing's instructions.
CONDITION 2 (Leading Edge is Distressed)
a. Do an inspection for cracking on the left and right vertical stabilizer front spar cap forward
flanges and either the aft flanges or side skins at Station Zfs=52.267 in accordance with
APPENDIX B, using one of the options as follows:
NOTE: The inspection area is defined as 12.50 inches +/- 0.25 inch above the leading edge
skin splice and 12.50 inches +/- 0.25 inch below the leading edge skin splice at
Station Zfs=52.267.
OPTION 1:
(1) Do an ETHF inspection of the left and right vertical stabilizer front spar cap forward flanges
as follows:
(a) Remove and keep fasteners common to the left and right vertical stabilizer front spar
cap forward flanges, above and below the leading edge skin splice at Station
Zfs=52.267.
(b) Do an open hole ETHF inspection of the left and right vertical stabilizer front spar
cap forward flanges at the fastener holes above and below the leading edge skin
splice at Station Zfs=52.267 in accordance with the inspection procedure in
APPENDIX B, Inspection Sequence 1.
(2) Do an RT inspection of the left and right vertical stabilizer front spar cap aft flanges in
accordance with the inspection procedure in APPENDIX B, Inspection Sequence 2 -
Option 1.
OPTION 2:
(1) Do an ETHF inspection of the left and right vertical stabilizer front spar cap forward flanges
as follows:
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(a) Remove and keep fasteners common to the left and right vertical stabilizer front spar
cap forward flanges, above and below the leading edge skin splice at Station
Zfs=52.267.
(b) Do an open hole ETHF inspection of the left and right vertical stabilizer front spar
cap forward flanges at the fastener holes above and below the leading edge skin
splice at Station Zfs=52.267 in accordance with the inspection procedure in
APPENDIX B, Inspection Sequence 1.
(2) Do an ETHF surface inspection of the side skin at the left and right vertical stabilizer front
spar cap aft flanges in accordance with the inspection procedure in APPENDIX B,
Inspection Sequence 2 - Option 2.
b. Based on inspection results, do as follows:
CONDITION 2A (No Crack Found during either Option 1 or Option 2 Inspection)
(1) Do leading edge repair in accordance with Service General Repair Drawing SG09550004.
NOTE: At operator's discretion, replace 9911813-503 vertical stabilizer leading edge
splice band or repair in accordance with Service General Repair Drawing
SG09550004.
(2) Install kept fasteners common to the left and right vertical stabilizer front spar cap forward
flanges.
(3) Install kept leading edge fasteners.
CONDITION 2B (Any Crack Found during either Option 1 or Option 2 Inspection)
(1) Do leading edge repair in accordance with Service General Repair Drawing SG09550004.
NOTE: At operator's discretion, replace 9911813-503 vertical stabilizer leading edge
splice band or repair in accordance with Service General Repair Drawing
SG09550004.
(2) Crack Found on the Vertical Stabilizer Front Spar Cap Forward Flange
(a) Remove and keep nut plate gang channel on the vertical stabilizer front spar cap
forward flange where the crack indication was found.
(b) Do an evaluation/verification to confirm any crack indication found on the vertical
stabilizer front spar cap forward flange. Refer to NDTSPM 06-00-07 for applicable
Crack/Defect Evaluation/Verification.
1) Crack Indication Not Confirmed
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a) Install kept nut plate gang channel on the vertical stabilizer front spar cap
forward flange.
b) Install kept fasteners common to the left and right vertical stabilizer front
spar cap forward flanges.
2) Crack Indication Confirmed
a) Contact Boeing for repair of the vertical stabilizer front spar cap forward
flange and do the repair in accordance with Boeing's instructions.
(3) Crack Found on the Vertical Stabilizer Side Skin or Front Spar Cap Aft Flange
(a) Do an evaluation/verification to confirm any crack indication found on the vertical
stabilizer side skins. Refer to NDTSPM 06-00-07 for applicable Crack/Defect
Evaluation/Verification.
1) Crack Indication Not Confirmed
a) Install kept leading edge fasteners.
2) Crack Indication Confirmed
a) Contact Boeing for repair of the vertical stabilizer side skins and do the
repair in accordance with Boeing's instructions.
(b) Do an evaluation/verification to confirm any crack indication found on the front spar
cap aft flange. Refer to NDTSPM 02-00-07 for applicable Crack/Defect
Evaluation/Verification.
1) Crack Indication Not Confirmed
a) Install kept leading edge fasteners.
2) Crack Indication Confirmed
a) Contact Boeing for repair of the vertical stabilizer front spar cap aft flange
and do the repair in accordance with Boeing's instructions.
CONDITION 3 (Leading Edge Existing Repair Found)
a. Do an inspection for cracking on the left and right vertical stabilizer front spar cap forward
flanges and either the aft flanges or side skins at Station Zfs=52.267 in accordance with
APPENDIX B, using one of the options as follows:
NOTE: The inspection area is defined as 12.50 inches +/- 0.25 inch above the leading edge
skin splice and 12.50 inches +/- 0.25 inch below the leading edge skin splice at
Station Zfs=52.267.
OPTION 1:
(1) Do an ETHF inspection of the left and right vertical stabilizer front spar cap forward flanges
as follows:
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(a) Remove and keep fasteners common to the left and right vertical stabilizer front spar
cap forward flanges, above and below the leading edge skin splice at Station
Zfs=52.267.
(b) Do an open hole ETHF inspection of the left and right vertical stabilizer front spar
cap forward flanges at the fastener holes above and below the leading edge skin
splice at Station Zfs=52.267 in accordance with the inspection procedure in
APPENDIX B, Inspection Sequence 1.
(2) Do an RT inspection of the left and right vertical stabilizer front spar cap aft flanges in
accordance with the inspection procedure in APPENDIX B, Inspection Sequence 2 -
Option 1.
OPTION 2:
(1) Do an ETHF inspection of the left and right vertical stabilizer front spar cap forward flanges
as follows:
(a) Remove and keep fasteners common to the left and right vertical stabilizer front spar
cap forward flanges, above and below the leading edge skin splice at Station
Zfs=52.267.
(b) Do an open hole ETHF inspection of the left and right vertical stabilizer front spar
cap forward flanges at the fastener holes above and below the leading edge skin
splice at Station Zfs=52.267 in accordance with the inspection procedure in
APPENDIX B, Inspection Sequence 1.
(2) Do an ETHF surface inspection of the side skin at the left and right vertical stabilizer front
spar cap aft flanges in accordance with the inspection procedure in APPENDIX B,
Inspection Sequence 2 - Option 2.
b. Based on inspection results, do as follows:
CONDITION 3A (No Crack Found during either Option 1 or Option 2 Inspection)
(1) Install kept fasteners common to the left and right vertical stabilizer front spar cap forward
flanges.
(2) Install kept leading edge fasteners.
CONDITION 3B (Any Crack Found during either Option 1 or Option 2 Inspection)
(1) Crack Found on the Vertical Stabilizer Front Spar Cap Forward Flange
(a) Remove and keep nut plate gang channel on the vertical stabilizer front spar cap
forward flange where the crack indication was found.
(b) Do an evaluation/verification to confirm any crack indication found on the vertical
stabilizer front spar cap forward flange. Refer to NDTSPM 06-00-07 for applicable
Crack/Defect Evaluation/Verification.
1) Crack Indication Not Confirmed
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a) Install kept nut plate gang channel on the vertical stabilizer front spar cap
forward flange.
b) Install kept fasteners common to the left and right vertical stabilizer front
spar cap forward flanges.
2) Crack Indication Confirmed
a) Contact Boeing for repair of the vertical stabilizer front spar cap forward
flange and do the repair in accordance with Boeing's instructions.
(2) Crack Found on the Vertical Stabilizer Side Skin or Front Spar Cap Aft Flange
(a) Do an evaluation/verification to confirm any crack indication found on the vertical
stabilizer side skins. Refer to NDTSPM 06-00-07 for applicable Crack/Defect
Evaluation/Verification.
1) Crack Indication Not Confirmed
a) Install kept leading edge fasteners.
2) Crack Indication Confirmed
a) Contact Boeing for repair of the vertical stabilizer side skins and do the
repair in accordance with Boeing's instructions.
(b) Do an evaluation/verification to confirm any crack indication found on the front spar
cap aft flange. Refer to NDTSPM 02-00-07 for applicable Crack/Defect
Evaluation/Verification.
1) Crack Indication Not Confirmed
a) Install kept leading edge fasteners.
2) Crack Indication Confirmed
a) Contact Boeing for repair of the vertical stabilizer front spar cap aft flange
and do the repair in accordance with Boeing's instructions.
3. Put the airplane back to a serviceable condition.
4. Do repetitive inspections of the vertical stabilizer leading edge structure at the splice at Station
Zfs=52.267, and the left and right vertical stabilizer front spar cap forward flanges and either the
aft flanges or side skins at Station Zfs=52.267, at intervals specified in Paragraph 1.E., Compliance.
PART B - REPETITIVE INSPECTION:
1. Inspection - Vertical Stabilizer Leading Edge:
a. Do a detailed inspection of the vertical stabilizer leading edge at the splice at Station Zfs=52.267
(fasteners not removed) for indications of loose fasteners and missing fasteners.
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NOTE: The inspection area is two rows of fasteners above the splice and two rows of
fasteners below the splice at Station Zfs=52.267.
b. Based on inspection results, do as follows:
CONDITION 4 (No Loose Leading Edge Fasteners and No Missing Leading Edge
Fasteners)
(1) Do repetitive detailed inspection of the vertical stabilizer leading edge at the splice at
Station Zfs=52.267 (fasteners not removed) for indications of loose fasteners and missing
fasteners at intervals specified in Paragraph 1.E., Compliance.
CONDITION 5 (Loose Leading Edge Fasteners or Missing Leading Edge Fasteners)
(1) Do leading edge repair in accordance with Service General Repair Drawing SG09550004.
NOTE: At operator's discretion, replace 9911813-503 vertical stabilizer leading edge
splice band or repair in accordance with Service General Repair Drawing
SG09550004.
(2) Do repetitive detailed inspection of the vertical stabilizer leading edge at the splice at
Station Zfs=52.267 (fasteners not removed) for indications of loose fasteners and missing
fasteners at intervals specified in Paragraph 1.E., Compliance.
2. Inspection - Vertical Stabilizer Front Spar Cap Forward Flanges and either the Aft Flanges or Side
Skins:
a. Do an inspection for cracking on the left and right vertical stabilizer front spar cap forward
flanges and either the aft flanges or side skins at Station Zfs=52.267 in accordance with
APPENDIX B, using one of the options as follows:
NOTE: The inspection area is defined as 12.50 inches +/- 0.25 inch above the leading edge
skin splice and 12.50 inches +/- 0.25 inch below the leading edge skin splice at
Station Zfs=52.267.
OPTION 1:
(1) Do an ETHF inspection of the left and right vertical stabilizer front spar cap forward flanges
as follows:
(a) Remove and keep fasteners common to the left and right vertical stabilizer front spar
cap forward flanges, above and below the leading edge skin splice at Station
Zfs=52.267.
(b) Do an open hole ETHF inspection of the left and right vertical stabilizer front spar
cap forward flanges at the fastener holes above and below the leading edge skin
splice at Station Zfs=52.267 in accordance with the inspection procedure in
APPENDIX B, Inspection Sequence 1.
(2) Do an RT inspection of the left and right vertical stabilizer front spar cap aft flanges in
accordance with the inspection procedure in APPENDIX B, Inspection Sequence 2 -
Option 1.
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OPTION 2:
(1) Do an ETHF inspection of the left and right vertical stabilizer front spar cap forward flanges
as follows:
(a) Remove and keep fasteners common to the left and right vertical stabilizer front spar
cap forward flanges, above and below the leading edge skin splice at Station
Zfs=52.267.
(b) Do an open hole ETHF inspection of the left and right vertical stabilizer front spar
cap forward flanges at the fastener holes above and below the leading edge skin
splice at Station Zfs=52.267 in accordance with the inspection procedure in
APPENDIX B, Inspection Sequence 1.
(2) Do an ETHF surface inspection of the side skin at the left and right vertical stabilizer front
spar cap aft flanges in accordance with the inspection procedure in APPENDIX B,
Inspection Sequence 2 - Option 2.
b. Based on inspection results, do as follows:
CONDITION 6 (No Crack Found during either Option 1 or Option 2 Inspection)
(1) Install kept fasteners common to the left and right vertical stabilizer front spar cap forward
flanges.
(2) Install kept leading edge fasteners.
CONDITION 7 (Any Crack Found during either Option 1 or Option 2 Inspection)
(1) Crack Found on the Vertical Stabilizer Front Spar Cap Forward Flange
(a) Remove and keep nut plate gang channel on the vertical stabilizer front spar cap
forward flange where the crack indication was found.
(b) Do an evaluation/verification to confirm any crack indication found on the vertical
stabilizer front spar cap forward flange. Refer to NDTSPM 06-00-07 for applicable
Crack/Defect Evaluation/Verification.
1) Crack Indication Not Confirmed
a) Install kept nut plate gang channel on the vertical stabilizer front spar cap
forward flange.
b) Install kept fasteners common to the left and right vertical stabilizer front
spar cap forward flanges.
2) Crack Indication Confirmed
a) Contact Boeing for repair of the vertical stabilizer front spar cap forward
flange and do the repair in accordance with Boeing's instructions.
(2) Crack Found on the Vertical Stabilizer Side Skin or Front Spar Cap Aft Flange
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(a) Do an evaluation/verification to confirm any crack indication found on the vertical
stabilizer side skins. Refer to NDTSPM 06-00-07 for applicable Crack/Defect
Evaluation/Verification.
1) Crack Indication Not Confirmed
a) Install kept leading edge fasteners.
2) Crack Indication Confirmed
a) Contact Boeing for repair of the vertical stabilizer side skins and do the
repair in accordance with Boeing's instructions.
(b) Do an evaluation/verification to confirm any crack indication found on the front spar
cap aft flange. Refer to NDTSPM 02-00-07 for applicable Crack/Defect
Evaluation/Verification.
1) Crack Indication Not Confirmed
a) Install kept leading edge fasteners.
2) Crack Indication Confirmed
a) Contact Boeing for repair of the vertical stabilizer front spar cap aft flange
and do the repair in accordance with Boeing's instructions.
3. Put the airplane back to a serviceable condition.
4. Do repetitive detailed inspection of the vertical stabilizer leading edge at the splice at Station
Zfs=52.267 (fasteners not removed) for indications of loose fasteners and missing fasteners at
intervals specified in Paragraph 1.E., Compliance.
5. Do repetitive inspection of the left and right vertical stabilizer front spar cap forward flanges and
either the aft flanges or side skins at Station Zfs=52.267 at intervals specified in Paragraph 1.E.,
Compliance.
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APPENDIX A: FLOWCHART - INITIAL INSPECTION AND REPETITIVE INSPECTION
1. This flowchart describes the initial inspection and repetitive inspection requirements and can be used as a
supplement to Paragraph 1.D., Description, Paragraph 1.E., Compliance, and Paragraph 3.B., Work
Instructions.
APPENDIX A:  FLOWCHART - INITIAL INSPECTION AND REPETITIVE INSPECTION
(SHEET 1 OF 3)
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### Page 42 (OCR)

BOEING SERVICE BULLETIN MD90-55A014
ALERT  ALERT
PART A
INITIAL INSPECTION
TABLE 1
TABLE 1
REMOVE TWO
FASTENER
ROWS ABOVE
AND BELOW  INSPECT VS FRONT
SPLICE AT Zfs =  52.267  LE DISTRESSED  CONDITION 2  SPAR CAP FWD AND AFT  FLANGE OR VS FRONT  FOUND  >  - CONDITION 2B -  YES  REPAIR LE
SPAR CAP FWD FLANGE
AND SIDE SKIN
INSPECT  NO
FOR "DISTRESS" IN  CONDITION 2A
AND EXISTING  CONTACT BOEING
REPAIRS TO VS  FOR REPAIR OF
LE STRUCTURE  ALL CRACKING
YES  REPAIR LE
DISTRESS OR
REPAIRED
PUT AIRPLANE
BACK TO
NO  SERVICEABLE
CONDITION 1  YES  CONDITION
INSPECT VS FRONT  INSPECT VS FRONT
CONTACT BOEING
SPAR CAP FWD AND AFT  LE REPAIRED  SPAR CAP FWD AND AFT  >  YES  FOR REPAIR OF
FLANGE OR VS FRONT  FLANGE OR VS FRONT
SPAR CAP FWD FLANGE  CONDITION 3  SPAR CAP FWD FLANGE  FOUND  CONDITION 3B  ALL CRACKING
AND SIDE SKIN  AND SIDE SKIN
CONDITION 3A
CONTACT BOEING
CRACK
FOUND  YES -  FOR REPAIR OF
CONDITION 1B  ALL CRACKING
PUT AIRPLANE
BACK TO
SERVICEABLE
NO
CONDITION 1A  CONDITION
PUT AIRPLANE
BACK TO
SERVICEABLE
CONDITION
CONTINUETO PART B
REPETITIVE INSPECTION
1987649
APPENDIX A: FLOWCHART - INITIAL INSPECTION AND REPETITIVE INSPECTION
(SHEET 2 OF 3)
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### Page 43 (OCR)

BOEING SERVICE BULLETIN MD90-55A014
ALERT  ALERT
PART B
REPETITIVE INSPECTIONS
TABLE 2 AND 3
TABLE 2  TABLE 3
INSPECT VS FRONT
LOOSE AND  REPEAT  SPAR CAP BASED ON
MISSING FASTENERS  INSPECTION  ACCOMPLISHMENT OF
OPTION 1 OR OPTION 2
FASTENERS
YES  REPAIR LE
LOOSE OR
MISSING  CONDITION 5  OPTION 1  OPTION 2
INSPECT VS  INSPECT VS
FRONT SPAR CAP  FRONT SPAR CAP
FWD AND AFT  FWD FLANGE AND
FLANGE  SIDE SKIN
NO
CONDITION 4
CONTACT BOEING
CRACK
FOUND  YES  FOR REPAIR OF ALL
CONDITION 7  CRACKING
NO
CONDITION 6
PUT AIRPLANE
BACK TO  REPEAT
SERVICEABLE  INSPECTION
CONDITION
1987650
APPENDIX A: FLOWCHART - INITIAL INSPECTION AND REPETITIVE INSPECTION
(SHEET 3 OF 3)
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### Page 44

APPENDIX B: INSPECTION OF VERTICAL STABILIZER FRONT SPAR CAP AT STATION ZFS=52.267
1. Model Affected: MD-90
2. Drawing Reference: 5912123, 5930609, 5911394, 9911833
Description:
1. The inspection area consists of the vertical stabilizer front spar caps at Station Zfs=52.267. The purpose
of Inspection Sequence 1 is to inspect the fastener holes common to the left and right front spar cap forward
flanges and leading edge panels in accordance with Figure 1. The purpose of Inspection Sequence 2 is to
detect fatigue cracks initiating at the fastener holes common to the left and right spar cap aft flanges and/or
side skins in accordance with Figure 2 or Figure 3. The fatigue cracks will travel in the forward and aft
directions from the fastener holes.
NOTE: Two inspection methods are acceptable for Inspection Sequence 2 as follows:
Option 1 - Radiographic Testing (RT)
Option 2 - Eddy Current, High Frequency (ETHF)
Inspection Sequence 1:
1. Eddy Current, High Frequency (ETHF)
Inspection Sequence 2:
1. Radiographic Testing (RT) or Eddy Current, High Frequency (ETHF)
Preparation for Inspection
1. Remove all dirt, grease, and loose paint from the inspection area.
2. Thoroughly clean the inspection area with an approved cleaning agent.
Table 1 - Equipment/Materials
SupplierCAGEQTYTypeTest Equipment
Staveley Instruments0M4211Sperry SPX 160Portable X-ray machine
(1.5 mm projected focal
spot).
1329 East Kemper Road
Cincinnati, Ohio 45246
APPENDIX B:  INSPECTION OF VERTICAL STABILIZER FRONT SPAR CAP AT STATION ZFS=52.267
(SHEET 1 OF 10)
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### Page 45

Table 1 - Equipment/Materials
SupplierCAGEQTYTypeTest Equipment
Eastman Kodak Company1913910Kodak MX-ray film
343 State Street(Refer to Table 2 for
sizes) Rochester, New York 14650
191394Kodak AAX-ray film
(Refer to Table 2 for
sizes)
Source Optional--For radiographic identifica-
tion.
Lead numbers
Source Optional---Masking Tape
Source Optional-In conformance with envi-
ronmental regulations and
harmless to surfaces con-
tacted.
Cleaning Agent
NOTE: The equipment/materials listed above were used to develop this procedure. Refer to NDTSPM
Part 02-00-04 and NDTSPM Part 06-00-04 for supplier/vendor information.
1.
2. Equipment/material substitutions producing results equivalent to those defined by this document
may also be used. Refer to NDTSPM Part 01-00-03, NDTSPM Part 02-00-03, and NDTSPM
Part 06-00-03 for equipment/material information.
Inspection Procedure:
1. Inspection Sequence 1 (Front Spar Cap Forward Flange Area)
Inspection Method 01 (Eddy Current, High Frequency)
a. Perform an open hole ETHF inspection of the left and right vertical stabilizer front spar cap forward
flanges above and below the leading edge skin splice at Station Zfs=52.267 within the specified
dimensions in accordance with Figure 1. Scan the circumference of the holes following the instructions
found in the Nondestructive Testing Standard Practice Manual NDTSPM 06-10-01.003 (ETHF -
Procedure 3).
NOTE: Scoring of the fastener hole bore caused by the removal of fasteners may cause crack-like
indications. Removal of nut plate may be necessary for proper clean up of the hole. Refer to
NDTSPM 06-10-01.003 "Access" and "Preparation and Cleaning" for further information. The
nut plate may also interfere with the probe scan with some open hole eddy current probe
designs.
APPENDIX B:  INSPECTION OF VERTICAL STABILIZER FRONT SPAR CAP AT STATION ZFS=52.267
(SHEET 2 OF 10)
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BOEING SERVICE BULLETIN MD90-55A014
ALERT  ALERT
VERTICAL STABILIZER
LEADING EDGE  FRONT SPAR CAP
PANEL
12.510.25
SIDE SKIN
CRACK
(TYPICAL)
Zfs = 52.267  OPEN HOLE EDDY CURRENT
INSPECT THE SPAR CAP WITHIN
THE SPECIFIED DIMENSION
(12.50 INCHES ‡0.25 ABOVE AND
12.510.25  BELOW STATION Zfs = 52.267)
DORSAL FIN
LOWER ASSEMBLY
A-A
LEFT SIDE SHOWN (RIGHT SIDE OPPOSITE)
VIEW LOOKING INBOARD FROM OUTSIDE
VERTICAL STABILIZER
HIGH FREQUENCY EDDY CURRENT INSPECTION OF
SPAR CAP FORWARD FLANGE AT STATION Zfs = 52.267  FIGURE 1  1955966
APPENDIX B: INSPECTION OF VERTICAL STABILIZER FRONT SPAR CAP AT STATION ZFS=52.267
(SHEET 3 OF 10)
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### Page 47

2. Inspection Sequence 2 (Front Spar Cap Aft Flange Area)
OPTION 1: Inspection Method 01 (Radiographic Testing)
a. Inspection for cracks of the vertical stabilizer front spar cap aft flange at Station Zfs=52.267 in accordance
with Figure 2.
NOTE: The following steps must be done to both left and right sides of the vertical stabilizer.
EXPOSURE 1:
(1) Prepare Exposure 1 radiographic identification tag with the data as follows, using operator's shop
practice:
– Service Bulletin number
– Exposure number and left or right side
– Aircraft I.D.
– Date
(2) Attach Exposure 1 identification tag to film pack for each exposure using operator's shop practice.
(3) Use masking tape to attach film to inspection element for Exposure 1 in accordance with Figure
2.
(4) Expose film in accordance with x-ray parameters in Table 2 and Figure 2.
EXPOSURE 2:
(1) Prepare Exposure 2 radiographic identification tag with the data as follows, using operator's shop
practice:
– Service Bulletin number
– Exposure number and left or right side
– Aircraft I.D.
– Date
(2) Attach Exposure 2 identification tag to film pack for each exposure using operator's shop practice.
(3) Use masking tape to attach film to inspection element for Exposure 2 in accordance with Figure
2.
(4) Expose film in accordance with x-ray parameters in Table 2 and Figure 2.
EXPOSURE 3:
(1) Prepare Exposure 3 radiographic identification tag with the data as follows, using operator's shop
practice:
APPENDIX B:  INSPECTION OF VERTICAL STABILIZER FRONT SPAR CAP AT STATION ZFS=52.267
(SHEET 4 OF 10)
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### Page 48

– Service Bulletin number
– Exposure number and left or right side
– Aircraft I.D.
– Date
(2) Attach Exposure 3 identification tag to film pack for each exposure using operator's shop practice.
(3) Use masking tape to attach film to inspection element for Exposure 3 in accordance with Figure
2.
(4) Expose film in accordance with x-ray parameters in Table 2 and Figure 2.
EXPOSURE 4:
(1) Prepare Exposure 4 radiographic identification tag with the data as follows, using operator's shop
practice:
– Service Bulletin number
– Exposure number and left or right side
– Aircraft I.D.
– Date
(2) Attach Exposure 4 identification tag to film pack for each exposure using operator's shop practice.
(3) Use masking tape to attach film to inspection element for Exposure 4 in accordance with Figure
2.
(4) Expose film in accordance with x-ray parameters in Table 2 and Figure 2.
EXPOSURE 5:
(1) Prepare Exposure 5 radiographic identification tag with the data as follows, using operator's shop
practice:
– Service Bulletin number
– Exposure number and left or right side
– Aircraft I.D.
– Date
(2) Attach Exposure 5 identification tag to film pack for each exposure using operator's shop practice.
(3) Use masking tape to attach film to inspection element for Exposure 5 in accordance with Figure
2.
(4) Expose film in accordance with x-ray parameters in Table 2 and Figure 2.
APPENDIX B:  INSPECTION OF VERTICAL STABILIZER FRONT SPAR CAP AT STATION ZFS=52.267
(SHEET 5 OF 10)
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### Page 49 (OCR)

BOEING SERVICE BULLETIN MD90-55A014
ALERT  ALERT
VERTICAL STABILIZER
LEADING EDGE  FRONT SPAR CAP
PANEL
3 TO 4 INCHES *
OVERLAP FILM
PLACEMENT  SIDE SKIN
1.5 INCHES I0.25
(4 PLACES)
B
FILM PLACEMENT
EXPOSURE 1
(SHOWN
10.010.25  TRANSPARENT)
12.5‡0.25  FILM PLACEMENT
EXPOSURE 2
(SHOWN
5.010.25  TRANSPARENT
FILM PLACEMENT
EXPOSURE 3
(SHOWN
5.0‡0.25  TRANSPARENT)
Zfs = 52.267
FILM PLACEMENT
EXPOSURE 4
10.010.25  SHOWN
12.5‡0.25  TRANSPARENT
FILM PLACEMENT
EXPOSURE 5
(SHOWN
TRANSPARENT)
•  INDICATES THE TARGET LOCATION OF
THE X-RAY TUBE HEAD PORT AT THE
DORSAL FIN  OPPOSITE SIDE OF THE VERTICAL
LOWER ASSEMBLY  STABILIZER TO THE CENTER OF THE
AREA BEING INSPECTED
A-A
LEFT SIDE SHOWN (RIGHT SIDE OPPOSITE)
VIEW LOOKING INBOARD FROM OUTSIDE
VERTICAL STABILIZER
TARGET SHOULD BE AFT OF AFT
FLANGE AND SLIGHTLY OBLIQUE, SO
THE FIRST FLANGE IS NOT
SUPERIMPOSED OVER THE FLANGE
BEING INSPECTED
RADIOGRAPHIC TESTING AT AFT FLANGE AT  STATION Zfs = 52.267  1955974
FIGURE 2 (SHEET 1)
APPENDIX B: INSPECTION OF VERTICAL STABILIZER FRONT SPAR CAP AT STATION ZFS-52.267
(SHEET 6 OF 10)
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BOEING SERVICE BULLETIN MD90-55A014
ALERT  ALERT
FILM PLACEMENT
(TYPICAL) \
DIM "A" -
(REFER TO TABLE 2)
18.7 ‡ 0.5-
B-B
VIEW LOOKING AFT
RADIOGRAPHIC TESTING AT AFT FLANGE AT
STATION Zfs = 52.267
FIGURE 2 (SHEET 2)
1987637
APPENDIX B: INSPECTION OF VERTICAL STABILIZER FRONT SPAR CAP AT STATION ZFS-52.267
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Table 2: Radiographic Exposure Data for Vertical Stabilizer Front Spar Cap Aft Flange at Station
Zfs=52.267
REMARKSFILMDIM "A"
(Inch)
mas
(a)
kVEXPOSURE
NUMBER SIZE
(Inch)
QTYASTM TYPE
5 X 721 (b)36 +/- 0.5600841
5 X 721 and 2 (c)36 +/- 0.5600842
5 X 721 and 2 (c)36 +/- 0.5600843
5 X 721 (b)36 +/- 0.5600844
5 X 721 (b)36 +/- 0.5600845
(a) May adjust mas as necessary to achieve a 1.7 to 3.5 H & D Density in the area of interest.
(b) Kodak M or equivalent type with similar speed.
(c) Kodak M and AA or equivalent type with similar speed (double load film pack).
OPTION 2: Inspection Method 01 (Eddy Current, High Frequency)
a. Perform an ETHF surface inspection of the vertical stabilizer side skins at those fasteners common to
the left and right vertical stabilizer front spar cap aft flanges within the specified dimensions in accordance
with Figure 3. Scan around the fasteners looking for cracks in the forward and aft direction. Scan around
fasteners following the instructions found in the Nondestructive Testing Standard Practice Manual
NDTSPM 06-10-01.001 (ETHF - Procedure 1). Use Calibration Method "P" and Scan Method "47".
APPENDIX B:  INSPECTION OF VERTICAL STABILIZER FRONT SPAR CAP AT STATION ZFS=52.267
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### Page 52 (OCR)

BOEING SERVICE BULLETIN MD90-55A014
ALERT  ALERT
VERTICAL STABILIZEH
LEADING EDGE  -RONT SPAR CAP
PANEL
+  +
+
• SIDE SKIN
12.5‡0.25  +
CRACK
(TYPICAL)
Zfs = 52.267
- EDDY CURRENT INSPECT THE
12.510.25  SIDE SKIN WITHIN THE SPECIFIED
DIMENSION (12.50 INCHES ‡0.25
ABOVE AND BELOW
STATION Zfs = 52.267)
+
• +
DORSAL FIN
LOWER ASSEMBLY
A-A
LEFT SIDE SHOWN (RIGHT SIDE OPPOSITE)
VIEW LOOKING INBOARD FROM OUTSIDE
VERTICAL STABILIZER
HIGH FREQUENCY EDDY CURRENT INSPECTION OF
SIDE SKIN AT AFT FLANGE AT STATION Zfs = 52.267  FIGURE 3  1956006
APPENDIX B: INSPECTION OF VERTICAL STABILIZER FRONT SPAR CAP AT STATION ZFS=52.267
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Inspection Results
1. Any indication is considered a crack which exhibits the same relative phase angle and an amplitude of 50
percent or greater than the indication obtained from the calibration notch in the reference standard.
2. Crack indications found during ETHF inspection shall be confirmed. Refer to NDTSPM 06-00-07 for applicable
Crack/Defect Evaluation/Verification sections(s).
3. Crack indications found during RT inspection shall be confirmed. Refer to NDTSPM 02-00-07 for applicable
Crack/Defect Evaluation/Verification section(s).
Post Inspection Procedure
1. Remove and secure all test equipment and materials from the area.
APPENDIX B:  INSPECTION OF VERTICAL STABILIZER FRONT SPAR CAP AT STATION ZFS=52.267
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