# Boeing Alert Service Bulletin MD90-55A015: No revision named

- Rights: © The Boeing Company. Filed by the FAA in regulations.gov docket FAA-2010-1202; AD 2011-06-12 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication.
- Document: [Boeing Alert Service Bulletin MD90-55A015](https://openairdocs.org/service-documents/boeing/md90-55a015.md)
- Title as filed: U.S. DOT/FAA - Service Bulletin
- Pages: 32
- PDF: https://openairdocs.org/files/sha256/00/d8/00d803246aef470413a2aabb313140e2139739ccf193411cbeaafb72b77ae92a
- Page: https://openairdocs.org/service-documents/boeing/md90-55a015/file/00d803246aef

## Text

Some pages are OCR from a scan. OCR can misread letters and numbers. Each page's text from the PDF; open the PDF at a page with #page=N.

### Page 1

Commercial 
Airplanes
MD90
Service Bulletin
ALERT
Number: MD90-55A015
Original Issue: July 16, 2010
ATA System: 5510
SUBJECT: STABILIZERS - Horizontal Stabilizer - Inspect/Replace Upper Center Skin Panels
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Unpublished Work - All Rights Reserved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.
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: July 16, 2010
MD90-55A015
1 of 32
3.0

### Page 2

BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: July 16, 2010
MD90-55A015
2 of 32
BOEING SERVICE BULLETIN MD90-55A015
ALERTALERT
BLANK PAGE

### Page 3

Table of Contents
Summary ...................................................... 5
1. PLANNING INFORMATION ........................................ 9
A. Effectivity ................................................ 9
1. Airplanes ............................................. 9
2. Spares Affected ........................................ 1 1
B. Concurrent Requirements ...................................... 1 1
C. Reason ................................................ 1 1
D. Description .............................................. 1 1
E. Compliance .............................................. 1 2
F. Approval ............................................... 1 6
G. Manpower .............................................. 1 7
H. Weight and Balance Changes .................................... 1 8
I. Electrical Load Data ......................................... 1 8
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
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 3
3. Parts Modified and Reidentified: ............................... 2 3
4. Parts Removed and Not Replaced: .............................. 2 4
D. Parts Necessary to Change Spares ................................. 2 4
E. Special Tooling - Price and Availability ............................... 2 4
F. Special Tooling Necessary to do this Service Bulletin ....................... 2 4
3. ACCOMPLISHMENT INSTRUCTIONS .................................. 2 5
A. GENERAL INFORMATION ..................................... 2 5
B. WORK INSTRUCTIONS ....................................... 2 6
FIGURE 1: HORIZONTAL STABILIZER LEFT AND RIGHT UPPER CENTER SKIN PANELS - EDDY
CURRENT INSPECTION ................................... 2 8
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: July 16, 2010
MD90-55A015
3 of 32
BOEING SERVICE BULLETIN MD90-55A015
ALERTALERT

### Page 4

BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: July 16, 2010
MD90-55A015
4 of 32
BOEING SERVICE BULLETIN MD90-55A015
ALERTALERT
BLANK PAGE

### Page 5

Commercial 
Airplanes
MD90
Service Bulletin
ALERT
SummaryNumber: MD90-55A015Original Issue: July 16, 2010
ATA System: 5510
SUBJECT: STABILIZERS - Horizontal Stabilizer - Inspect/Replace Upper Center Skin Panels
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
During inspection of the horizontal stabilizer upper aft skin panel of an MD-80 airplane in accordance with Service
Bulletin MD80-55A065, one operator reported finding a crack in the right horizontal stabilizer upper center skin
panel at the aft inboard corner. The MD-80 airplane had accumulated 47,146 flight-hours and 26,490 flight cycles
when the crack was found. The cause of the horizontal stabilizer upper center skin panel cracking on the MD-80
airplane is suspected to be fatigue. The MD-90 horizontal stabilizer is similar in design and loading as that of
the MD-80 horizontal stabilizer. Boeing issued Service Bulletin MD90-55A012 which provides instructions to do
inspection of the horizontal stabilizer upper aft skin panel. If undetected, a crack in the upper center skin panel
may transfer load to the upper aft skin panel. This may result in the upper aft skin panel cracking faster than the
existing inspection intervals, defined in Service Bulletin MD90-55A012, will detect. Inspection of the affected
areas will determine the condition of the horizontal stabilizer upper center skin panels. If not corrected, undetected
cracks may ultimately lead to the loss of overall structural integrity of the horizontal 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
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.
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: July 16, 2010
MD90-55A015
5 of 32

### Page 6

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
Boeing Supplied Kits/Parts.
Refer to Paragraph 2.A., Material - Price and Availability.
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: July 16, 2010
MD90-55A015
6 of 32
BOEING SERVICE BULLETIN MD90-55A015
ALERTALERT

### Page 7 (OCR)

BOEING SERVICE BULLETIN MD90-55A015
ALERT  ALERT
INSPECT/REPLACE UPPER
CENTER SKIN PANELS
1974629
Original Issue: July 16, 2010
MD90-55A015
Copyright © Unpublished Work - See page 1 for details.  BOEING PROPRIETARY -  7 of 32

### Page 8

BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: July 16, 2010
MD90-55A015
8 of 32
BOEING SERVICE BULLETIN MD90-55A015
ALERTALERT
BLANK PAGE

### Page 9

Commercial 
Airplanes
MD90
Service Bulletin
ALERT
Number: MD90-55A015
Original Issue: July 16, 2010
ATA System: 5510
SUBJECT: STABILIZERS - Horizontal Stabilizer - Inspect/Replace Upper Center Skin Panels
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
12133
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: July 16, 2010
MD90-55A015
9 of 32

### Page 10

GroupFuselage Num-
ber
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
12250 - 2251
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: July 16, 2010
MD90-55A015
10 of 32
BOEING SERVICE BULLETIN MD90-55A015
ALERTALERT

### Page 11

GroupFuselage Num-
ber
12253
12255 - 2263
12288 - 2290
14001 - 4002
2. Spares Affected
None.
B. Concurrent Requirements
None.
C. Reason
During inspection of the horizontal stabilizer upper aft skin panel of an MD-80 airplane in accordance
with Service Bulletin MD80-55A065, one operator reported finding a crack in the right horizontal stabilizer
upper center skin panel at the aft inboard corner. The MD-80 airplane had accumulated 47,146
flight-hours and 26,490 flight cycles when the crack was found. The cause of the horizontal stabilizer
upper center skin panel cracking on the MD-80 airplane is suspected to be fatigue. The MD-90 horizontal
stabilizer is similar in design and loading as that of the MD-80 horizontal stabilizer. Boeing issued
Service Bulletin MD90-55A012 which provides instructions to do inspection of the horizontal stabilizer
upper aft skin panel. If undetected, a crack in the upper center skin panel may transfer load to the upper
aft skin panel. This may result in the upper aft skin panel cracking faster than the existing inspection
intervals, defined in Service Bulletin MD90-55A012, will detect. Inspection of the affected areas will
determine the condition of the horizontal stabilizer upper center skin panels. If not corrected, undetected
cracks may ultimately lead to the loss of overall structural integrity of the horizontal stabilizer.
D. Description
This service bulletin provides instructions to do an eddy current inspection of the horizontal stabilizer
left and right upper center skin panels for cracks, and based on inspection results for each panel, does
as follows:
Condition 1 (No Crack Found)
1. Does repetitive eddy current inspections of the horizontal stabilizer upper center skin panel.
Condition 2 (Crack Found)
1. OPTION 1:
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: July 16, 2010
MD90-55A015
11 of 32
BOEING SERVICE BULLETIN MD90-55A015
ALERTALERT

### Page 12

a. Replaces the cracked horizontal stabilizer upper center skin panel.
b. Does repetitive eddy current inspection of the replacement horizontal stabilizer upper center
skin panel.
2. OPTION 2:
a. Contacts Boeing for possible temporary repair of crack and does the repair in accordance
with Boeing's instructions.
The work in this service bulletin is done in the maintenance zone(s) given below.
Affected Maintenance Zones
ZoneModel
333, 343MD-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.
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: July 16, 2010
MD90-55A015
12 of 32
BOEING SERVICE BULLETIN MD90-55A015
ALERTALERT

### Page 13

Table 1: Inspect Horizontal Stabilizer Left and Right Upper Center Skin Panels for Cracks
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
-Within 3,778
flight cycles af-
ter the original
issue date on
this service bul-
letin.
Before the accu-
mulation of
20,000 total
flight cycles.
Do initial eddy current in-
spection of the horizontal
stabilizer left and right
upper center skin panels
in accordance with Para-
graph 3.B., Work Instruc-
tions, using one of the
options as follows:
All Airplanes
OPTION 1:
Scan 1 - Eddy Current,
High Frequency (ETHF)
Scan 2 - Eddy Current,
High Frequency (ETHF)
Scan 3 - Eddy Current,
Low Frequency (ETLF)
OR
OPTION 2:
Scan 1 - Eddy Current,
High Frequency (ETHF)
Scan 2 - Eddy Current,
High Frequency (ETHF)
Scan 3 - Eddy Current,
High Frequency (ETHF)
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: July 16, 2010
MD90-55A015
13 of 32
BOEING SERVICE BULLETIN MD90-55A015
ALERTALERT

### Page 14

Table 1: Inspect Horizontal Stabilizer Left and Right Upper Center Skin Panels for Cracks
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
---Do repetitive eddy current
inspection of the horizon-
tal stabilizer left and right
upper center skin panels
in accordance with Para-
graph 3.B., Work Instruc-
tions, using one of the
options as follows:
Condition 1
(No Crack Found)
5,200 flight cycles-Within 5,200
flight cycles af-
ter doing the ini-
tial eddy current
inspection.
OPTION 1:
Scan 1 - Eddy Current,
High Frequency (ETHF)
Scan 2 - Eddy Current,
High Frequency (ETHF)
(a)
(a)Scan 3 - Eddy Current,
Low Frequency (ETLF)
OR
2,500 flight cycles-Within 2,500
flight cycles af-
ter doing the ini-
tial eddy current
inspection.
OPTION 2:
Scan 1 - Eddy Current,
High Frequency (ETHF)
Scan 2 - Eddy Current,
High Frequency (ETHF)
(a)
(a)Scan 3 - Eddy Current,
High Frequency (ETHF)
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: July 16, 2010
MD90-55A015
14 of 32
BOEING SERVICE BULLETIN MD90-55A015
ALERTALERT

### Page 15

Table 1: Inspect Horizontal Stabilizer Left and Right Upper Center Skin Panels for Cracks
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
---OPTION 1: Do items (1),
(2), and (3) as follows:
Condition 2
(Crack Found)
--Before further
flight
(1) Replace the cracked
horizontal stabilizer upper
center skin panel in accor-
dance with Paragraph
3.B., Work Instructions
AND
--Within 20,000
flight cycles af-
ter installation of
the replacement
horizontal stabi-
lizer upper cen-
ter skin panel.
(2) Do initial eddy current
inspection of the replace-
ment horizontal stabilizer
upper center skin panel
in accordance with Para-
graph 3.B., Work Instruc-
tions, using one of the
options as follows:
OPTION 1:
Scan 1 - Eddy Current,
High Frequency (ETHF)
Scan 2 - Eddy Current,
High Frequency (ETHF)
Scan 3 - Eddy Current,
Low Frequency (ETLF)
OR
OPTION 2:
Scan 1 - Eddy Current,
High Frequency (ETHF)
Scan 2 - Eddy Current,
High Frequency (ETHF)
Scan 3 - Eddy Current,
High Frequency (ETHF)
AND
---(3) Do repetitive eddy
current inspection of the
horizontal stabilizer left
and right upper center
skin panels in accordance
with Paragraph 3.B.,
Work Instructions, using
one of the options as fol-
lows:
5,200 flight cycles.-OPTION 1:
(a)
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: July 16, 2010
MD90-55A015
15 of 32
BOEING SERVICE BULLETIN MD90-55A015
ALERTALERT

### Page 16

Table 1: Inspect Horizontal Stabilizer Left and Right Upper Center Skin Panels for Cracks
Repeat Interval
(Not to Exceed)
Compliance Time (Whichever
Occurs Later)
ActionCondition
Scan 1 - Eddy Current,
High Frequency (ETHF)
Within 5,200
flight cycles af-
ter doing the ed-
dy current in-
spection.
Scan 2 - Eddy Current,
High Frequency (ETHF)
Scan 3 - Eddy Current,
Low Frequency (ETLF) (a)
OR
2,500 flight cycles-Within 2,500
flight cycles af-
ter doing the ed-
dy current in-
spection.
OPTION 2:
Scan 1 - Eddy Current,
High Frequency (ETHF)
Scan 2 - Eddy Current,
High Frequency (ETHF)
(a)
(a)Scan 3 - Eddy Current,
High Frequency (ETHF)
OR
--Before further
flight
OPTION 2:
Contact Boeing for possi-
ble temporary repair of
crack and do the repair in
accordance with Boeing's
instructions.
Condition 2
(Crack Found)
(a) It is acceptable to change inspection procedures from Option 1 to Option 2 or from Option 2 to Option 1
if you do as follows:
1. If the inspection procedure is being changed from Option 1 to Option 2, the first Option 2 inspection must
be done within 5,200 flight cycles after the Option 1 inspection. The Option 2 inspections that follows must
be done within 2,500 flight cycle repeat intervals
2. If the inspection procedure is being changed from Option 2 to Option 1, the first Option 1 inspection must
be done within 2,500 flight cycles after the Option 2 inspection. The Option 1 inspections that follows must
be done within 5,200 flight cycle repeat intervals
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.
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: July 16, 2010
MD90-55A015
16 of 32
BOEING SERVICE BULLETIN MD90-55A015
ALERTALERT

### Page 17

G. Manpower
The table below shows an estimate of the task hours necessary to do the inspection and/or configuration
changes for each horizontal stabilizer upper center skin panel. 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.
All Airplanes: Horizontal Stabilizer Upper Center Skin Panel Initial Inspection
Elapsed HoursTask HoursNumber of PersonsTask
2.04.02Figure 1 - Inspection
2.04.0TOTAL FOR EACH UPPER CENTER SKIN
PANEL
Condition 1: Horizontal Stabilizer Upper Center Skin Panel Repetitive Inspection
Elapsed HoursTask HoursNumber of PersonsTask
2.04.02Figure 1 - Inspection
2.04.0TOTAL FOR EACH UPPER CENTER SKIN
PANEL
Condition 2, Option 1: Horizontal Stabilizer Upper Center Skin Panel Replacement
Elapsed HoursTask HoursNumber of PersonsTask
8.048.06Remove Horizontal
Stabilizer
12.024.02Remove Leading
Edge and Upper For-
ward Skin Panel
168.0504.03Replace Horizontal
Stabilizer Upper
Center Skin Panel
12.024.02Install Leading Edge
and Upper Forward
Skin Panel
8.048.06Install Horizontal
Stabilizer
208.0648.0TOTAL FOR EACH UPPER CENTER SKIN
PANEL
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: July 16, 2010
MD90-55A015
17 of 32
BOEING SERVICE BULLETIN MD90-55A015
ALERTALERT

### Page 18

H. Weight and Balance Changes
None.
I. Electrical Load Data
Not changed.
J. References
1. Existing Data:
a. Non-Destructive Test Standard Practices Manual (NDTSPM) 06-00-07, 06-10-01.001,
06-10-02.005.
b. MD90 Aircraft Maintenance Manual (AMM) 55-10-01, 55-12-01.
2. Data supplied with this Service Bulletin:
None.
3. Installation Drawings Used in the Preparation of this Service Bulletin:
ChangeTitleDocument Number
TPANEL-SKIN AND STGR, HORIZ
STAB, CTR
5922577
KSTRUCTURAL ASSEMBLY - OUTER
PANEL HORIZONTAL STABILIZER
5964815
ESTABILIZER ASSY-COMPLETE
HORIZONTAL
5940483
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:
None.
2. Damage Tolerance Based Structural Inspections:
Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue
Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the
Maintenance Program. This service bulletin affects FCS. DTI requirements for the structure affected
are contained in Paragraph 1.E., Compliance of this service bulletin.
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: July 16, 2010
MD90-55A015
18 of 32
BOEING SERVICE BULLETIN MD90-55A015
ALERTALERT

### Page 19

L. Interchangeability and Intermixability of Parts
Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts.
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: July 16, 2010
MD90-55A015
19 of 32
BOEING SERVICE BULLETIN MD90-55A015
ALERTALERT

### Page 20

BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: July 16, 2010
MD90-55A015
20 of 32
BOEING SERVICE BULLETIN MD90-55A015
ALERTALERT
BLANK PAGE

### Page 21

2.    MATERIAL INFORMATION
A. Material - Price and Availability
Boeing can supply the kits shown below which contain the parts listed in Paragraph 2.C., Parts Necessary
for Each Airplane. Operators are encouraged to share schedule requirements with Boeing for
incorporation of the service bulletin. The kits are subject to the terms and conditions of the Boeing
standard purchase order acknowledgment. Prices are in United States Dollars. Terms: Net 30 days.
Reference this service bulletin and submit your purchase order by one of these methods:
1. Order on-line via ATA Spec 2000 or The Boeing PART Page
2. Fax to (206) 662-7145
REFER TO THE BOEING PART PAGE ON MYBOEINGFLEET.COM OR CONTACT FIRST RE-
SPONDER AT FR@BOEING.COM FOR THE LATEST REORDER LEAD TIME (ROLT) AND PRICE
INFORMATION
Unit Price as of
the original issue
date of this Ser-
vice Bulletin (US
Dollars)
ROLT as of the
original issue
date of this Ser-
vice Bulletin (Cal-
endar Days)
NameKit Number
$55,608.00120Service Kit - Upper CenterSA90550015-3
Skin Panel (Left)
55,608.00120Service Kit - Upper CenterSA90550015-5
Skin Panel (Right)
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:
To get the kits/parts shown below, refer to Paragraph 2.A., Material - Price and Availability.
NOTE: One top kit per panel location (left or right) and the items shown in Paragraph 2.C.2.,
Parts and Materials Supplied by the Operator, are necessary for each airplane.
SERVICE KIT APPLICABILITY
SR Drawing ConfigurationNameSA Kit Number
SR09550033-7017Service Kit - Upper CenterSA90550015-3
Skin Panel (Left)
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: July 16, 2010
MD90-55A015
21 of 32
BOEING SERVICE BULLETIN MD90-55A015
ALERTALERT

### Page 22

SERVICE KIT APPLICABILITY
SR Drawing ConfigurationNameSA Kit Number
SR09550033-7019Service Kit - Upper CenterSA90550015-5
Skin Panel (Right)
Kit SA90550015
NotesExisting Part
Number
NameQTYNew Part Number
-5-3
(a).-SA90550015-3
(a)-.SA90550015-5
(b)3964835-509FILLER663964835-509
(c)3964835-511FILLER883964835-511
NUT ASSEMBLY113D0006-3
NUT, BARREL443D0011-5
BARREL NUT333D0011-6
RETAINER443D0012-5
RETAINER333D0012-6
BOLT333D0031-5-22
BOLT113D0031-5-26
BOLT333D0031-6-24
5922577-511UPPER PANEL
(RIGHT)
1.5922577-511
5922577-512UPPER PANEL
(LEFT)
.15922577-512
WASHER4473232-5-8.1
WASHER3373232-6-12.4
PIN1414HLT435-6-3
PIN2727HLT435-6-4
PIN77HLT435-6-5
PIN55HLT435-6-6
PIN22HLT435-6-8
PIN7373HLT435-8-3
PIN4343HLT435-8-4
RIVET1212MS20426AD5-6D
RIVET4444MS20426AD5-7D
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: July 16, 2010
MD90-55A015
22 of 32
BOEING SERVICE BULLETIN MD90-55A015
ALERTALERT

### Page 23

Kit SA90550015
NotesExisting Part
Number
NameQTYNew Part Number
-5-3
RIVET66MS20426AD5-8D
RIVET88MS20426AD6-8D
RIVET1616MS20470AD6-7D
RIVET2222MS20470AD6-8D
NUT5858MS21042L3
NUT116116MS21042L4
RIVET5454NAS1097KE8-10D
RIVET22NAS1097KE8-11D
RIVET1818NAS1097KE8-12D
RIVET147147NAS1097KE8-9D
WASHER5858NAS1252-10L
WASHER116116NAS1252-416L
PIN44S4931919-6-5
(a) If grip length shown is not available at Boeing, fasteners supplied in kits may
be one grip length longer than indicated. Also, if any fasteners part numbers
listed are not available or have been superseded, substitute fasteners may be
supplied in kits.
(b) 5930603-7 Filler may be used in lieu of 3964835-509 Filler.
(c) 5930603-9 Filler may be used in lieu of 3964835-511 Filler.
2. Parts and Materials Supplied by the Operator:
NotesQTYNamePart Number/Specification
(a)As RequiredSealantPR-1422 B-2
(DMS 2082)
or
Equivalent
CAGESupplier
83574PRC - DeSoto International, Incorporated(a) Can be purchased from:
24811 Avenue Rockefeller
Valencia, California 91355 -3468
3. Parts Modified and Reidentified:
None.
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: July 16, 2010
MD90-55A015
23 of 32
BOEING SERVICE BULLETIN MD90-55A015
ALERTALERT

### Page 24

4. Parts Removed and Not Replaced:
None.
D. Parts Necessary to Change Spares
None.
E. Special Tooling - Price and Availability
None.
F. Special Tooling Necessary to do this Service Bulletin
No special tools or equipment are necessary to do the change in this service bulletin. But, maintenance
and overhaul tools in the manuals given in Paragraph 1.J., References, can be necessary. Examine
operator tool supply to make sure all necessary tools are available.
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: July 16, 2010
MD90-55A015
24 of 32
BOEING SERVICE BULLETIN MD90-55A015
ALERTALERT

### Page 25

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 MD-90 Structural Repair Manual (SRM) 51.
5. If the length of any fastener specified in this service bulletin does not meet the
installation standards in MD-90 SRM 51, then a fastener of the same specification,
or an approved substitute, with a length which meets the installation standards in
MD-90 SRM 51 may be used.
6. A 1/8-inch thick stack of the same type washers called for in this service bulletin is
the maximum thickness which may be used under fastener head or nut to counteract
accumulation of tolerances.
EXCEPTION: When the available fastener length increments are greater than
1/16-inch, a 3/16-inch thick stack of the same type washers may be used.
7. 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 are in MD-90 SRM 51.
– Torque limits to tighten nuts and bolts are in MD-90 SRM 51.
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: July 16, 2010
MD90-55A015
25 of 32
BOEING SERVICE BULLETIN MD90-55A015
ALERTALERT

### Page 26

8. Obey all of the warnings and cautions given in the specified manual sections.
9. 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.
10. Some Boeing parts are supplied in a temporary configuration. Those parts are
identified with a 'U' or 'Y' in place of the '-' (dash) in the part number. It is permitted
to install parts identified with a 'U' or 'Y' as an alternative to the '-' (dash) number
part. Boeing Drawing SE10000000, Sheets 5.0 and 6.0 contain more data.
B. WORK INSTRUCTIONS
1. Do an eddy current inspection of the horizontal stabilizer left and right upper center skin panels in
accordance with FIGURE 1 and based on inspection results for each panel, do as follows:
Condition 1 (No Crack Found)
a. Do repetitive eddy current inspections of the horizontal stabilizer upper center skin panel in
accordance with FIGURE 1, at intervals specified in Paragraph 1.E., Compliance.
Condition 2 (Crack Found)
a. OPTION 1:
(1) Remove and keep horizontal stabilizer. Refer to MD90 AMM 55-10-01.
(2) Remove and keep horizontal stabilizer leading edge. Refer to MD90 AMM 55-12-01.
(3) Remove and keep horizontal stabilizer upper forward skin panel to gain access to the
cracked horizontal stabilizer upper center skin panel. Refer to drawing 5964815.
(4) Remove and replace the cracked horizontal stabilizer upper center skin panel in
accordance with the applicable configuration of Service Rework Drawing SR09550033
using the applicable kit as follows:
KIT
SA90550015
CENTER SKIN
PANEL LOCATION
DRAWING
SR09550033
-3UPPER LEFT-7017
-5UPPER RIGHT-7019
(5) Install kept horizontal stabilizer upper forward skin panel. Refer to drawing 5964815 and
MD90 SRM 51.
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: July 16, 2010
MD90-55A015
26 of 32
BOEING SERVICE BULLETIN MD90-55A015
ALERTALERT

### Page 27

(6) Install kept horizontal stabilizer leading edge. Refer to MD90 AMM 55-12-01.
(7) Install kept horizontal stabilizer. Refer to MD90 AMM 55-10-01.
(8) Do repetitive eddy current inspection of the replacement horizontal stabilizer upper center
skin panel in accordance with FIGURE 1, at intervals specified in Paragraph 1.E.,
Compliance.
b. OPTION 2:
(1) Contact Boeing for possible temporary repair of crack and do the repair in accordance
with Boeing's instructions.
2. Put the airplane back to serviceable condition.
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: July 16, 2010
MD90-55A015
27 of 32
BOEING SERVICE BULLETIN MD90-55A015
ALERTALERT

### Page 28 (OCR)

BOEING SERVICE BULLETIN MD90-55A015
ALERT  ALERT
.35 + .05
STGR.3
IBD
25 +
XH=7.234
UPPER PANEL
LOOKING DOWN  LEFT SIDE  1975758
FIGURE 1: HORIZONTAL STABILIZER LEFT AND RIGHT UPPER CENTER SKIN PANELS - EDDY CURRENT
INSPECTION
(SHEET 1 OF 5)
Original Issue: July 16, 2010
BOEING PROPRIETARY -  MD90-55A015
Copyright © Unpublished Work - See page 1 for details.  28 of 32

### Page 29 (OCR)

BOEING SERVICE BULLETIN MD90-55A015
ALERT  ALERT
SCAN PARALLEL TO EDGE
.35 + .05
INBD
STGR.3
.25 + .10
2.5 + .10
XH=7.234
UPPER PANEL
LEFT SIDE
LOOKING DOWN  1975767
FIGURE 1: HORIZONTAL STABILIZER LEFT AND RIGHT UPPER CENTER SKIN PANELS - EDDY CURRENT
INSPECTION
(SHEET 2 OF 5)
Original Issue: July 16, 2010
MD90-55A015
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.  29 of 32

### Page 30 (OCR)

BOEING SERVICE BULLETIN MD90-55A015
ALERT  ALERT
.35 + .05
STGR.3
.25 + .10
XH=7.234
UPPER PANEL
RIGHT SIDE
LOOKING DOWN
1975771
FIGURE 1: HORIZONTAL STABILIZER LEFT AND RIGHT UPPER CENTER SKIN PANELS - EDDY CURRENT
INSPECTION
(SHEET 3 OF 5)
Original Issue: July 16, 2010
BOEING PROPRIETARY -  MD90-55A015
Copyright © Unpublished Work - See page 1 for details.  30 of 32

### Page 31 (OCR)

BOEING SERVICE BULLETIN MD90-55A015
ALERT  ALERT
- SCAN PARALLEL TO EDGE
.35 + .05
INBD
STGR.3
.25 + .10
2.5 + .10
XH=7.234
UPPER PANEL
RIGHT SIDE
LOOKING DOWN  1975774
FIGURE 1: HORIZONTAL STABILIZER LEFT AND RIGHT UPPER CENTER SKIN PANELS - EDDY CURRENT
INSPECTION
(SHEET 4 OF 5)
Original Issue: July 16, 2010
MD90-55A015
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.  31 of 32

### Page 32

The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY
numbers shown below are the number of parts necessary for each airplane.
MORE DATAQTYIDENTIFICATIONNAMETASKSTEP
(a) (e)15922577-511Upper Center Skin
Panel - Right
Inspect - (Scan 1)
OPTION 1, 2:
1
Eddy Current, High
Frequency (ETHF) 5922577-512Upper Center SkinPanel - Left
(b) (e)15922577-511Upper Center Skin
Panel - Right
Inspect - (Scan 2)
OPTION 1, 2:
2
Eddy Current, High
Frequency (ETHF) 5922577-512Upper Center SkinPanel - Left
(c) (e)15922577-511Upper Center Skin
Panel - Right
Inspect - (Scan 3)
OPTION 1:
3
Eddy Current, Low
Frequency (ETLF) 5922577-512Upper Center SkinPanel - Left
(d) (e)15922577-511Upper Center Skin
Panel - Right
Inspect - (Scan 3)
OPTION 2:
Eddy Current, High
Frequency (ETHF) 5922577-512Upper Center SkinPanel - Left
Do an Eddy Current, High Frequency surface inspection of the horizontal stabilizer upper center
skin panels around the fastener in the inspection area. Scan around the fastener using a nonconduc-
tive circle template looking for cracks propagating from the fastener hole. Refer to NDTSPM 06-10-
01.001 (ETHF - Procedure 1). Use Calibration Method "P" and Scan Method "47".
(a)
Do an Eddy Current, High Frequency surface inspection of the horizontal stabilizer upper center
skin panels along the inboard portion of the aft edge as shown in the inspection area. Scan the edges
looking for cracks propagating from the panel edge. Refer to NDTSPM 06-10-01.001 (ETHF - Pro-
cedure 1). Use Calibration Method "A" and Scan Method "79".
(b)
Do an Eddy Current, Low Frequency sub-surface inspection of the horizontal stabilizer upper center
skin panels at all other areas in the rectangular shaped inspection area not inspected by Scan 1 or
2. Scan the noted area of the upper surface of the upper panels. Refer to NDTSPM 06-10-02.005
(ETLF - Procedure 5).
(c)
NOTE:
Space each scan approximately 1/2 probe coil diameter apart.
Do an Eddy Current, High Frequency surface inspection of the horizontal stabilizer upper center
skin panels at all other areas in the rectangular shaped inspection area not inspected by Scan 1 or
2. Scan the noted area of the upper surface of the upper panels. Refer to NDTSPM 06-10-01.001
(ETHF - Procedure 1).Use Calibration Method "C" and Scan Method "61".
(d)
NOTE:
Space each scan approximately 1/2 probe coil diameter apart.
Evaluate and verify crack indications found during inspection. Refer to NDTSPM 06-00-07.(e)
FIGURE 1: HORIZONTAL STABILIZER LEFT AND RIGHT UPPER CENTER SKIN PANELS - EDDY CURRENT
INSPECTION
(SHEET 5 OF 5)
BOEING PROPRIETARY -
Copyright © Unpublished Work - See page 1 for details.
Original Issue: July 16, 2010
MD90-55A015
32 of 32
BOEING SERVICE BULLETIN MD90-55A015
ALERTALERT

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain, except the copies of manufacturers’ service documents, which belong to their rights holders.