Revision ‘C’ 04 Nov 2014

DHC ---8 (DASH 8)

SERVICE BULLETIN 8 ---24 ---89

Electrical Power Generation, DC System --- Introduction of DC

Generation Control Unit (Goodrich) with Under Voltage Protection to

Channel #1 Main Engine --- ModSum 8Q101925

This page transmits Revision ‘C’ of Service Bulletin 8 ---24 ---89, pages 1 thru

10 dated 04 Nov 2014.

This service bulletin is re ---issued in its entirety for the reasons that follow:

--- Figure 2 is revised to show the correct part number for the label

WAS: 81151169 ---101 NOW: 81151169 ---103

--- the References section is revised to convey the latest revision of the service

bulletin and engineering documentation.

The Compliance in the previous issues of this service bulletin is not affected

by this revision. No additional rework to the aircraft is introduced by this

revision.

Operators that have incorporated the Initial Issue of this service bulletin are

not required to do any further work. No additional rework to the aircraft is

introduced by this revision.

Remove previous revision of Service Bulletin 8 ---24 ---89 and replace with

attached.

Previous issues of Service Bulletin 8 ---24 ---89:

Initial issue --- Pages 1 thru 10 dated 14 Nov 2011

Revision ’A’ --- Pages 1 thru 10 dated 08 Aug 2012

Revision ’B’ --- Pages 1 thru 10 dated 09 Apr 2014

D

S.B. 8 ---24 ---89

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SERVICE BULLETIN

Customer

Support

ATA SYSTEM: 2400 NUMBER: 8 ---24 ---89

SUBJECT: Electrical Power Generation, DC System --- Introduction of

DC Generation Control Unit (Goodrich) with Under Voltage

Protection to Channel #1 Main Engine --- ModSum 8Q101925

1. PLANNING INFORMATION

A. Effectivity

Aircraft Affected:

In ---Service: DHC ---8 Aircraft Models 102, 103, 106, 201, 202, 301, 311,

314 and 315 Serial Numbers 003 thru 672 with Goodrich GCU

Part Number 51539 ---008B or 51539 ---008C or 51539 ---008D

installed.

NOTE: The instructions in this service bulletin are only applicable to

the systems and parts installed at the time of delivery on the

aircraft or as changed by Bombardier Aerospace Service

Bulletin(s). Before you do this bulletin, examine all STC or

equivalent action changes to make sure this bulletin can be

completed.

Spares Affected:

None

B. Reason

Problem: Since 1995, operators have reported four occurrences of un ---annunciated

failure of the No. 1 DC Starter Generator. This has prompted emergency

descent and landings resulting from the illumination of numerous caution

indications of affected systems.

Functionality of the FMS and NAV systems were reportedly lost. The

transponder systems were also reported to no longer function with the
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exception of the No. 2 ADF.

Given DC Bus and Main/Aux Battery architecture, this failure mode is only

applicable to the Left Main DC Bus and #1 Engine generator channel.

Solution: Install a new DC GCU with under ---voltage protection.

C. Description

The procedures in this service bulletin give the instructions to do the tasks that

follow:

--- aircraft is put into standard configuration for maintenance

--- aircraft electrical power is removed

--- the nose landing gear lock is engaged

--- the main landing gear lock pins are installed through each main gear and main

gear door mechanism

--- access is gained to the Generator Control Unit (GCU) located in the right DC circuit

breaker console on the bottom shelf

--- the existing GCU is removed and replaced with a new GCU

--- the existing connector identification label is removed and replaced with a new label

--- close out.

D. Compliance

Bombardier Inc. recommends incorporation of ModSum 8Q101925 at the earliest

opportunity unless otherwise directed by the operator’s airworthiness authority.

E. Approval

The technical content of this service bulletin has been approved under the

authority of the Transport Canada Civil Aviation (TCCA) Design Approval

Organization No: DAO #93 ---Q ---02.

This Service Bulletin does not affect Airworthiness Limitations (AWLs) or Damage

Tolerance Inspections (DTIs).
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F. Manpower

It will take an estimated 3.00 man ---hours to complete this service bulletin. The

breakdown of the man ---hours is shown in the table that follows:

TASK MAN ---HOURS

Job Set ---Up 0.50

Procedure 1.00

Test / RTS 1.00

Close ---Out 0.50

For any on---site labor assistance, please speak with a Fleet Services representative for

a quote. The Fleet Services group can be contacted via the Q Series Technical Help

Desk by telephone at 416---375---4000 or email at: thd.qseries@aero.bombardier.com

G. Material --- Price and Availability

The part(s) and material(s) detailed in Paragraph 2.A. may be either furnished or

fabricated from the operator’s existing stock or purchased as single items from

Bombardier Aerospace Regional Aircraft. DK parts are to be manufactured and

approved locally (refer to disclaimer in the related text or illustration). In some

cases, an equivalent to the DK part may be available from Bombardier under the

production part number shown as reference in Parts Required Per Aircraft.

H. Tooling --- Price and Availability

None

I. Weight and Balance

None

J. Electrical Load Data

Not affected

K. Publications Affected

Dash 8 Illustrated Parts Catalogue PSM 1 ---8 ---4 and ....................

PSM 1 ---82 ---4 and

PSM 1 ---83 ---4

Modifications Manual PSM 1 ---813 ---12 ...............................
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L. References

Revision ‘C’ of this service bulletin was prepared to the engineering drawings and

related data that follows:

DRAWING SHEET REV

8DK4177 1 A

ModSum 8Q101925 Rev. ‘G’

PCA 05625 Revision 5 (for internal reference only)

2. MATERIAL INFORMATION

A. Parts Required Per Aircraft

(1) Detailed Parts List:

Quantity Per

Aircraft

Part Number Description Remarks

1 81151169 ---103 Label, GCU Warning Label

1 51539 ---021A GCU 1

B. Parts Required to Modify Spares

None

C. Special Tools and Equipment Required

None

D. Existing Parts Accountability

The following parts may be affected by this service bulletin. Indented parts are

components of the next higher assembly. The quantity (Qty.) column lists the

quantity that may be affected per aircraft for non ---indented parts and the quantity

per next higher assembly for indented parts.
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Existing

Part Number Description Qty. IC DC

New Part

Number PNC

--- Label, GCU 1 N/A DIS 81151169 ---103 N

51539 ---008B

or

51539 ---008C GCU 1 1 N/A SAL 51539 ---021A N

or

51539 ---008D

IC Interchangeability Code

A Not interchangeable.

B Removed Part. No direct replacement.

C Conditionally Interchangeable. Installation of superseded part negates the

intent of this service bulletin.

N/A Not Applicable.

DC Disposition

DIS Discard Part.

MUI Multiple Usage Item: Return to stock if serviceable.

RWK Rework existing part in accordance with this service bulletin.

RWI Rework existing part per .....

SAL Salvage. Return to operator’s stores for salvage consideration.

PNC Part Number Code

N New part.

R Part number after rework.

S Superseding or equivalent part number.

X Reworked part and superseding part are functionally and physically

equivalent but not identical.
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3. ACCOMPLISHMENT INSTRUCTIONS

A. Job Set ---Up

WARNING: YOU MUST INSTALL THE LOCKPINS ON THE MAIN LANDING GEAR.

MAKE SURE YOU ENGAGE THE NOSE GEAR LOCK. IF YOU DO NOT

DO THIS, THE LANDING GEAR CAN ACCIDENTALLY RETRACT. THIS

CAN CAUSE INJURIES TO PERSONS AND DAMAGE TO THE

EQUIPMENT.

WARNING: YOU MUST INSTALL THE LOCKPINS ON THE LANDING GEAR

DOORS. MAKE SURE YOU DISCONNECT THE LANDING GEAR

DOORS. IF YOU DO NOT DO THIS THE LANDING GEAR DOORS WILL

CLOSE WHEN YOU APPLY THE HYDRAULIC PRESSURE. THIS CAN

CAUSE INJURIES TO PERSONS AND DAMAGE TO THE EQUIPMENT.

(1) Refer to PSM 1 ---8 ---2 or PSM 1 ---82 ---2 or PSM 1 ---83 ---2 Chapter 24 and obey

all electrical / electronic safety precautions.

(2) Refer to PSM 1 ---8 ---2 or PSM 1 ---82 ---2 or PSM 1 ---83 ---2 Chapter 24 and obey all

electrostatic discharge safety precautions.

(3) Placard and select all aircraft electrical power to OFF. Refer to PSM 1 ---8 ---2 or

PSM 1 ---82 ---2 or PSM 1 ---83 ---2 Chapters 12 and 24 and obey the applicable

WARNINGS and CAUTIONS.

(4) Make sure that lock pins are installed through each main gear and main gear

door mechanism.

(5) Make sure the nose gear ground lock is engaged.

(6) Open and tag the circuit breakers that follow on the left DC circuit breaker panel:

(a) DC LOGIC (F9)

(b) DC GEN1 EXCITE (G9)

(c) L MAIN INPUT (L9)

(d) AUX BATT INPUT (M9).

(7) Refer to Figure 1 and gain access to the GCU located in the right DC circuit

breaker console on the bottom shelf.
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B. Procedure

(1) Refer to Figure 1 and AMM Chapter 24 ---31 ---03 (100 or 300 series) or AMM

TASK 24 ---31 ---16 ---000 ---801 (200 series) and replace the existing #1 GCU with

new GCU 51539 ---021A.

(2) Refer to Figure 2 and AMM Chapter 20 ---22 ---02 (100 or 300 series) or AMM

TASK 20 ---22 ---02 ---400 ---801 (200 series) and remove and replace the existing

GCU label with new warning label 81151169 ---103.

(3) Refer to Figure 1 and close access to the new GCU.

C. Close Out

(1) Close the circuit breakers that follow on the left DC circuit breaker panel:

(a) DC LOGIC (F9)

(b) DC GEN1 EXCITE (G9)

(c) L MAIN INPUT (L9)

(d) AUX BATT INPUT (M9).

(2) Remove all tools and equipment from the work area.

(3) On incorporation of this ModSum, make an entry that conforms to local

regulatory requirements in the applicable logbook(s). Enter component serial

numbers if applicable. Enter this ModSum number only after complete and

functional incorporation of all work defined in this service bulletin.

THE DESIGN OF THE PART IN THIS DRAWING HAS BEEN APPROVED BY DE HAVILLAND INC. FOR MANUFACTURE BY OR ON BEHALF OF

THE RECIPIENT. THE RECIPIENT IS RESPONSIBLE FOR (A) PROPER MANUFACTURE OF THE PART USING THE SPECIFIED MATERIALS

AND FOR INCORPORATION OF THE MODIFICATION, ALL IN ACCORDANCE WITH THE DRAWING AND RELATED INSTRUCTIONS, AND (B)

APPROVAL OF THE FINAL INSTALLATION BY THE RELEVANT AIRWORTHINESS AUTHORITY. DE HAVILLAND INC. AND BOMBARDIER INC.

(BOMBARDIER AEROSPACE REGIONAL AIRCRAFT) DISCLAIM ANY RESPONSIBILITY FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES,

INCLUDING WITHOUT LIMITATION LOSS OR USE, LOSS OF REVENUE OR LOSS OF PROFIT, ARISING FROM SUCH MANUFACTURE,

INCORPORATION AND INSTALLATION.
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DC Generator Control Unit --- Removal / Installation

Figure 1

A

A

B

B
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Label Location

Figure 2

WARNING LABEL

81151169 ---103

OR

8DK4177 ---101 (MANUFACTURED BY OPERATOR)
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Warning Label 8DK4177 ---101

Figure 3

8DK4177 ---101

4.50 INCHES

1.13 INCHES

1
Jan 2009

SERVICE BULLETIN (SB) --- RECORD OF INCORPORATION

--- Q SERIES DASH 8 AIRCRAFT

To: CMDB Focal

Facsimile: (1) 416 375 4538

E --mail: cmdb.requests@aero.bombardier.com

From:

Company:

Phone: Extn:

Facsimile: Date:

E --mail:

The data that you provide below will help us record the incorporation of this ModSum

and the aircraft effectivity in the maintenance manual.

Operator: Service Bulletin: __________________ Revision: _________

Aircraft Serial Number: Model Number: Date Bulletin Completed:

Aircraft Serial Number: Model Number: Date Bulletin Completed:

Aircraft Serial Number: Model Number: Date Bulletin Completed:

Aircraft Serial Number: Model Number: Date Bulletin Completed:

Aircraft Serial Number: Model Number: Date Bulletin Completed:

Aircraft Serial Number: Model Number: Date Bulletin Completed:

Aircraft Serial Number: Model Number: Date Bulletin Completed:

Aircraft Serial Number: Model Number: Date Bulletin Completed:

Aircraft Serial Number: Model Number: Date Bulletin Completed:

Aircraft Serial Number: Model Number: Date Bulletin Completed:

Aircraft Serial Number: Model Number: Date Bulletin Completed:

Aircraft Serial Number: Model Number: Date Bulletin Completed:

Fax this sheet to (1) 416 375 4538 or Email PDF to:

cmdb.requests@aero.bombardier.com
Feb 2009

SERVICE BULLETIN (SB) --- COMMENT SHEET --- Q SERIES DASH 8 AIRCRAFT

To: SB Focal (Toronto), Bombardier Aerospace Commercial Aircraft

Phone: (1) 416 375 4078 Facsimile: (1) 416 375 4538

E --mail: syed.rizvi@aero.bombardier.com

From:

Company:

Phone: Extn:

Facsimile: Date:

E --mail:

Select appropriate box(es) and add comments or suggestions you would like us to know

that may enhance the quality of our service bulletins.

Service Bulletin: Revision: ModSum:

1. PLANNING INFORMATION

V Effectivity V Reason V Description V Compliance

V Approval V Manpower V Material V Weight and Balance

V Electrical Load V Tooling V References V Publications Affected

2. MATERIAL INFORMATION

V Kit Content V Special Tools/Equipment V Parts to Modify Spares

V Consumables V Disposition of Existing Parts V Other

3. ACCOMPLISHMENT INSTRUCTIONS

V Job Set ---Up V Procedure V Close---Out V Test

V Illustration(s) V Other

4. COMMENTS, REMARKS, SUGGESTIONS

Fax this sheet to (1) 416 375 4538 or Email PDF to:

syed.rizvi@aero.bombardier.com