Commercial 

Airplanes MD90

Service Bulletin

ALERT

Number: MD90-74A002

Original Issue: August 17, 2010

ATA System: 7400

SUBJECT: ENGINE IGNITION - Ignition - Change Fire Handle Shutoff System Wire Routing

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.

ECCN: 9E991

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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Unpublished Work - All Rights Reserved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,

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BLANK PAGE
Table of Contents

Summary ...................................................... 5

1. PLANNING INFORMATION ........................................ 9

A. Effectivity ................................................ 9

1. Airplanes ............................................. 9

2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

B. Concurrent Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

C. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

E. Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

H. Weight and Balance Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

1. Existing Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

2. Data supplied with this Service Bulletin: . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

3. Installation Drawings Used in the Preparation of this Service Bulletin: . . . . . . . . . . . 13

K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

2. MATERIAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

A. Material - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

C. Parts Necessary For Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

1. Kits/Parts: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

2. Parts and Materials Supplied by the Operator: . . . . . . . . . . . . . . . . . . . . . . . . 16

3. Parts Modified and Reidentified: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

4. Parts Removed and Not Replaced: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

D. Parts Necessary to Change Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

E. Special Tooling - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

F. Special Tooling Necessary to do this Service Bulletin . . . . . . . . . . . . . . . . . . . . . . . 17

3. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

B. WORK INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

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Commercial 

Airplanes MD90

Service Bulletin

ALERT

Summary Number: MD90-74A002

Original Issue: August 17, 2010

ATA System: 7400

SUBJECT: ENGINE IGNITION - Ignition - Change Fire Handle Shutoff System Wire Routing

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

The engine fire shutoff handles on the MD-90 airplanes are designed to shutoff fuel at both the wing spar's

mechanical fuel fire shutoff valve as well as the electrical solenoid controlled engine fuel shutoff valve in the

engine Hydromechanical Unit (HMU). The feature is unique to the MD-90 airplanes and would result in an

automatic shutoff of the fuel at the engine HMU when the affected fire handle is pulled. Due to the lack of

separation between engine wires, a latent failure in the fire handle fuel shutoff relay circuit has the potential of

causing a dual engine shutdown in the event any single engine fuel fire shutoff handle is actuated. Separating

the fire handle shutoff system wiring will minimize the possibility of multiple engine shutdown due to single event.

If not corrected, inadequate separation has the potential of causing a dual engine shutdown in the event any

single engine fuel fire shutoff handle is activated.

ACTION

This service bulletin provides instructions for operators to change the wire routing for the fire handle shutoff

system.

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.

Boeing recommends that the wire routing change for the fire handle shutoff system be done within 4,200

flight-hours after the original issue date on this service bulletin.

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INDUSTRY SUPPORT INFORMATION

Boeing warranty remedies are not available for the configuration changes given in this service bulletin.

MANPOWER

Airplanes Total Task Hours Elapsed Hours

MD-90-30 7.9 7.9

MATERIAL INFORMATION

Boeing supplied Parts/Materials.

Refer to Paragraph 2.A., Material - Price and Availability.

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BLANK PAGE
Commercial 

Airplanes MD90

Service Bulletin

ALERT

Number: MD90-74A002

Original Issue: August 17, 2010

ATA System: 7400

SUBJECT: ENGINE IGNITION - Ignition - Change Fire Handle Shutoff System Wire Routing

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:

GROUP CONFIGURATION DESCRIPTION

1 - Change Fire Handle Shutoff System Wire Routing

Airplane Models:

MD-90-30

Fuselage Num- Group

ber

2094 - 2100 1

2115 1

2117 1

2120 1

2122 - 2123 1

2125 - 2126 1

2129 1

2131 1

2133 1

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Fuselage Num- Group

ber

2136 1

2138 1

2140 - 2144 1

2146 - 2147 1

2149 - 2150 1

2153 - 2154 1

2156 - 2159 1

2161 - 2166 1

2169 - 2171 1

2173 1

2175 1

2177 1

2179 1

2181 - 2182 1

2184 1

2186 1

2190 - 2191 1

2193 - 2195 1

2197 - 2198 1

2200 1

2202 - 2203 1

2205 1

2207 1

2209 - 2213 1

2215 - 2217 1

2219 - 2233 1

2235 - 2237 1

2240 1

2243 1

2245 1

2248 1

2250 - 2251 1

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Fuselage Num- Group

ber

2253 1

2255 - 2263 1

2288 - 2290 1

4001 - 4002 1

2. Spares Affected

None.

B. Concurrent Requirements

None.

C. Reason

The engine fire shutoff handles on the MD-90 airplanes are designed to shutoff fuel at both the wing

spar's mechanical fuel fire shutoff valve as well as the electrical solenoid controlled engine fuel shutoff

valve in the engine Hydromechanical Unit (HMU). The feature is unique to the MD-90 airplanes and

would result in an automatic shutoff of the fuel at the engine HMU when the affected fire handle is

pulled. Due to the lack of separation between engine wires, a latent failure in the fire handle fuel shutoff

relay circuit has the potential of causing a dual engine shutdown in the event any single engine fuel

fire shutoff handle is actuated. Separating the fire handle shutoff system wiring will minimize the

possibility of multiple engine shutdown due to single event. If not corrected, inadequate separation has

the potential of causing a dual engine shutdown in the event any single engine fuel fire shutoff handle

is activated.

D. Description

This service bulletin provides instructions for operators to change the wire routing for the fire handle

shutoff system.

The work in this service bulletin is done in the maintenance zone(s) given below.

Affected Maintenance Zones

Model Zone

MD-90-30 114, 211

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 recommends that the wire routing change for the fire handle shutoff system be done within

4,200 flight-hours after the original issue date on this service bulletin.

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F. Approval

This service bulletin was examined by the Federal Aviation Administration (FAA). The changes specified

in this service bulletin comply with the applicable regulations and are FAA approved, as well as European

Aviation Safety Agency (EASA)/Joint Aviation Authorities (JAA) approved for all EASA/JAA approved

airplanes listed in the service bulletin effectivity. This service bulletin and its approval were based on

the airplane in its original Boeing delivery configuration or as modified by other approved Boeing

changes.

If an airplane has a non-Boeing modification or repair that affects a component or system also affected

by this service bulletin, the operator is responsible for obtaining appropriate regulatory agency approval

before incorporating this service bulletin.

G. Manpower

The table below shows an estimate of the task hours necessary to do this inspection/modification for

each airplane. This estimate is for direct labor only, done by an experienced crew. Adjust the estimate

with operator task hour data if necessary. The estimate does not include lost time. These are some

examples of lost time:

• Time to adjust to the workplace

• Time to schedule the work

• Time to inspect the work

• Time to cure the materials

• Time to make the parts

• Time to find the tools.

Task Number of Persons Task Hours Elapsed Hours

Open Circuit Breaker 1 0.2 0.2

Open Access 1 0.5 0.5

Change and Coil/Stow 1 6.5 6.5

Wires

Close Circuit Breaker 1 0.2 0.2

Close Access 1 0.5 0.5

TOTAL FOR EACH AIRPLANE 7.9 7.9

H. Weight and Balance Changes

Moment Change

(MEW) IN.-LBS

Mfr's Empty

Weight (MEW)

LBS

Approximate StaAirplane tion (Inches)

MD-90-30 + 140.0 + 0.6 + 84.0

I. Electrical Load Data

Not changed.

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J. References

1. Existing Data:

a. Standard Wiring Practices Manual (SWPM) 20-00-03, 20-00-09, 20-00-13, 20-00-16, 20-10-01,

20-10-04, 20-20-01, 20-20-02, 20-31-00.

b. MD90 Aircraft Maintenance Manual (AMM) 06-31-00, 06-32-00, 24-00-00.

2. Data supplied with this Service Bulletin:

No data is supplied with this service bulletin. To obtain the data necessary to support this service

bulletin submit a data request to:

Data and Services Management

MS D800-0019

3855 Lakewood Boulevard

Long Beach, California 90846

Phone: (562) 593-6996

Fax: (562) 593-2001

E-mail: dse.boecom@boeing.com

a. Drawings:

Drawing No Title Sheet DCN/REV ADCN

FIRE HANDLE SHUTOFF SYS WIRE DWG C -

SEPARATION

SR90740002

3. Installation Drawings Used in the Preparation of this Service Bulletin:

Document Number Title Change

WIRE INSTALLATION - UPPER BR

NOSE

5964560

WIRE INSTALLATION - LOWER DD

NOSE

5964562

WIRE INSTALLATION - ELECTRI- BJ

CAL POWER CENTER, OVHD SW

PNLS & HOUSING

5964566

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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Publication Chapter-Section

Wiring Diagram Manual 26-11-013, 74-11-011, 74-11-012

2. Damage Tolerance Based Structural Inspections:

Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue

Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the

Maintenance Program. This service bulletin does not affect FCS, therefore DTIs are not necessary.

L. Interchangeability and Intermixability of Parts

Refer to Paragraph 2.C., Parts Necessary for Each Airplane, for interchangeability and intermixability

information.

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ALERT ALERT
2. MATERIAL INFORMATION

A. Material - Price and Availability

Boeing can supply the parts shown in Paragraph 2.C., Parts Necessary for Each Airplane. Operators

are encouraged to share schedule requirements with Boeing for incorporation of the service bulletin.

The parts are subject to the terms and conditions of the Boeing standard purchase order

acknowledgment. Prices are in United States Dollars. Terms: Net 30 days.

Reference this service bulletin and submit your purchase order by one of these methods:

1. Order on-line via ATA Spec 2000 or The Boeing PART Page

2. Fax to (206) 662-7145

REFER TO THE BOEING PART PAGE ON MYBOEINGFLEET.COM OR CONTACT FIRST RESPONDER

AT FR@BOEING.COM FOR THE LATEST REORDER LEAD TIME (ROLT) AND PRICE INFORMATION

Unit Price as of

the original issue

date of this Service Bulletin (US

Dollars)

ROLT as of the

original issue

date of this Service Bulletin (Calendar Days)

Kit Number Name

SA90740002-3 Service Kit 90 $489.00

B. Industry Support Information

Boeing warranty remedies are not available for the configuration changes given in this service bulletin.

C. Parts Necessary For Each Airplane

1. Kits/Parts:

Kit SA90740002

New Part Number QTY Name Existing Part Number Notes

-3 -101

SA90740002-3 - -

SA90740002-101 1 - WIRE PACKAGE

.125 I.D. X - SLEEVE DMS 2109

310 IN.

SR90740002-3

(a)

END CAP, T/C

914

CYW20 10 -

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Kit SA90740002

New Part Number QTY Name Existing Part Number Notes

-3 -101

Remove and install socket or pin.

Refer to SWPM

20-00-16.

SOCKET, T/C

1123

DC39-16S 1 -

SOCKET, T/C

1124

DC39-20S 1 -

D2426-1C-20NM - 310 IN. WIRE CODE 801 (b)

SA90740002-5 - 2 SLEEVE

(1/8 DIA X 2.0

INCHES)

(DMS 2399, Type 3

or Equivalent)

DPM 6101 - 2 TAG

(a) SR90740002-5 (DMS 2379) sleeving is an approved alternate for SR90740002-3 (DMS 2109) sleeving.

(b) Refer to SWPM 20-00-13 Table 206 for approved alternate wires.

2. Parts and Materials Supplied by the Operator:

Part Number/ Specifi- QTY Name Notes

cation

9D0254-1-1-9 As Required STRAP, TIEDOWN (a)

or

(PLT2S-9 or SST2S-9) (b)

or

Equivalent

18 DZ BLK As Required TAPE, LACING & TYING (c)

(DPM 731-6)

or

Equivalent

18XTZ or 23XTZ As Required TAPE, TYPING, GLASS FIBER

(DMS 2089)

or

Equivalent

(a) Can be purchased from: The Boeing Company CAGE

7755 East Marginal Way South 81205

Seattle, Washington 98108

(b) Can be purchased from: Panduit Corporation 06383

17301 Ridgeland Avenue

Tinley Park, Illinois 60477

(c) Can be purchased from: Gudebrod, Incorporated 7F993

262 King Street

Pottstown, Pennsylvania 19464

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3. Parts Modified and Reidentified:

None.

4. Parts Removed and Not Replaced:

None.

D. Parts Necessary to Change Spares

None.

E. Special Tooling - Price and Availability

None.

F. Special Tooling Necessary to do this Service Bulletin

No special tools or equipment are necessary to do the change in this service bulletin. But, maintenance

and overhaul tools in the manuals given in Paragraph 1.J., References, can be necessary. Examine

operator tool supply to make sure all necessary tools are available.

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BLANK PAGE
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. Refer to these SWPM chapters for applicable operations, as accepted procedures:

– SWPM 20-00-03 - Identification of Electrical wires.

– SWPM 20-00-09 - Electrical Identification and Shop Practice.

– SWPM 20-00-13 - Alternate wire type list.

– SWPM 20-00-16 - Electrical Wire End Termination Codes.

– SWPM 20-10-01 - Wire Installation Procedures.

– SWPM 20-10-04 - Coil and Stow Excess wire Length.

– SWPM 20-20-01 - Copper Electrical Terminals - Commercial.

– SWPM 20-20-02 - Terminal Junction Blocks - Commercial.

– SWPM 20-31-00 - Electrical Connectors - General Requirement - Commercial.

5. Review and understand all general notes of Service Rework Drawing SR90740002,

sheets 3.0 and 3.1.

6. Obey all of the warnings and cautions given in the specified manual sections.

7. These work instructions refer to procedures included in other Boeing documents.

When the words "refer to" are used and the operator has an accepted alternative

procedure, the accepted alternative procedure can be used. When the words "in

accordance with" are included in the instruction, the procedure in the Boeing document

must be used.

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B. WORK INSTRUCTIONS

1. Remove electrical power from airplane. Refer to MD90 AMM 24-00-00 as an accepted procedure.

2. Gain access to area of modification by opening the access doors as follows:

ACCESS DOOR LOCATION MORE DATA

Electrical/Electronic (E/E) Com- MD90 AMM 06-31-00

partment

110BL

Upper Nose Pedestal Floor, MD90 AMM 06-32-00

STA 120.000

Wire Trough Cover

Electrical Power Center (EPC) Forward Cabin EPC MD90 AMM 06-32-00

Shroud

3. Open circuit breakers and install safety tags as follows:

Location Row/Col Number Name

Lower EPC U/34 B1-1097 Left Engine Start Switch

Lower EPC X/39 B1-1096 Right Engine Start Switch

Lower EPC Z/32 B1-1079 Left Fuel Shutoff Solenoid

Lower EPC W/42 B1-192 Fire Warning Lights

Overhead Panel B/10 B1-1080 Right Fuel Shutoff Solenoid

4. Disconnect, coil and stow existing wire in accordance with Service Rework Drawing SR90740002,

sheet 7.0.

5. Install new wire in accordance with Service Rework Drawing SR90740002, sheet 7.0.

6. Disconnect, coil and stow wires in accordance with Service Rework Drawing SR90740002, sheets

4.0, 4.1, 6.7, 6.8, and General Notes 16 and 20.

7. Do a continuity check on new wire.

8. Remove safety tags and close circuit breakers as follows:

Location Row/Col Number Name

Lower EPC U/34 B1-1097 Left Engine Start Switch

Lower EPC X/39 B1-1096 Right Engine Start Switch

Lower EPC Z/32 B1-1079 Left Fuel Shutoff Solenoid

Lower EPC W/42 B1-192 Fire Warning Lights

Overhead Panel B/10 B1-1080 Right Fuel Shutoff Solenoid

9. Close the access doors as follows:

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ACCESS DOOR LOCATION MORE DATA

Electrical/Electronic (E/E) Com- MD90 AMM 06-31-00

partment

110BL

Upper Nose Pedestal Floor, MD90 AMM 06-32-00

STA 120.000

Wire Trough Cover

Electrical Power Center (EPC) Forward Cabin EPC MD90 AMM 06-32-00

Shroud

10. Restore electrical power to airplane. Refer to MD90 AMM 24-00-00 as an accepted procedure.

11. Put the airplane back to a serviceable condition.

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Original Issue: August 17, 2010

MD90-74A002

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BOEING SERVICE BULLETIN MD90-74A002

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