Revision ‘D’ 10 Apr 2014

DHC ---8 (DASH 8)

SERVICE BULLETIN 8 ---24 ---84

Electrical Power --- DC System --- Introduction of New Phoenix GCU Part

Number with Undervoltage Protection and Performance Improvements,

#1 Engine Generator Channel --- ModSum 8Q101710

This page transmits Revision ‘D’ of Service Bulletin 8 ---24 ---84, pages 1 thru

18 dated 10 Apr 2014

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

--- the Effectivity section is revised

--- added new statement after the Production Effectivity

--- Approval section is revised to add the statement for Airworthiness

Limitations (AWLs) and Damage Tolerance Inspections (DTIs)

--- Manpower section is revised to include a breakdown of the time required

and on ---site labor assistance information

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

bulletin and engineering documentation.

--- the Parts Required Per Aircraft section is revised with statement in the

Remarks column of the Parts List for label 81151169

--- the Existing Parts Accountability section is revised with additional Existing

Part Number

--- the ACCOMPLISHMENT INSTRUCTIONS section is revised with the

changes that follow:

--- separated Procedure section into Part 1 and Part 2

--- added ‘or GC ---1010 ---24 ---5II’ to step (1) of Part 1.

The Compliance in the previous issue(s) 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 Revision ‘C’ of this service bulletin are not

required to do any further work. No additional rework to the aircraft is

introduced by this revision.

Remove Service Bulletin 8 ---24 ---84 Revision ‘C’ dated 07 Jul 2009 and

replace with attached.
Previous issue(s) of Service Bulletin 8 ---24 ---84:

Initial issue --- Pages 1 thru 10 dated 22 Aug 2008

Revision ‘A’ --- Pages 1 thru 10 dated 23 Aug 2008

Revision ‘B’ --- Pages 1 thru 10 dated 15 Oct 2008

Revision ‘C’ --- Pages 1 thru 10 dated 07 Jul 2009

D

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SERVICE BULLETIN

Customer

Support

ATA SYSTEM: 2461 NUMBER: 8 ---24 ---84

SUBJECT: Electrical Power --- DC System --- Introduction of New Phoenix GCU

Part Number with Undervoltage Protection and Performance

Improvements, #1 Engine Generator Channel --- ModSum 8Q101710

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 661 with GCU part

number GC ---1010 ---24 ---5DIII or GC ---1010 ---24 ---5DII

installed.

Production: ModSum 8Q101710 has already been installed on applicable

DHC ---8 Aircraft at Serial Number 662 and subsequent

For Serial Numbers 003 thru 661 with GCU part number 51539 ---008B or

51539 ---008C or 51539 ---008D installed, see Bombardier Service Bulletin 8 ---24 ---89.

Spares Affected:

None

B. Reason

Problem: Four occurrences of un ---annunciated failure of the No. 1 DC Starter

Generator have been reported since 1995. This caused a low voltage

condition of the Left Main DC Bus and prompted emergency descents

and landings resulting from the illumination of numerous caution

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

transponder systems were also reported to no longer function with the

exception of the No. 2 ADF.

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

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

channel.

Solution: This service bulletin conveys ModSum 8Q101710. The modsum installs

a new Generator Control Unit (GCU) with undervoltage protection,

added filtering to the current transformer inputs to address nuisance

trips and additional modifications designed to improve GCU

performance.

C. Description

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

follow:

--- access is gained to the flight compartment

--- the existing #1 Generator Control Unit (GCU) located on the bottom of the

co ---pilots circuit breaker console is removed and replaced with a new GCU part

number GC ---1010 ---24 ---5DV according to the ACCOMPLISHMENT

INSTRUCTIONS in this service bulletin and the enclosed vendor service bulletin

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

--- a new GCU warning label is installed

--- an operational test of the DC generator system is done

--- close out.

D. Compliance

Bombardier Inc. recommends incorporation of ModSum 8Q101710 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(s) 2.A. may be either furnished or

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

Bombardier Aerospace Regional Aircraft or purchased directly from industry

sources. 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
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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 ...............................

L. References

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

related data that follows:

DRAWING SHEET REV

8DK4141 1 A

ModSum 8Q101710 Rev. ‘H’

Phoenix Aerospace Inc. Service Bulletin #: 000331 ---1 DATE: AUG 29/08

PCA 05625 Revision 5 (for internal reference only)

PCA 05918 Revision NC (for internal reference only)

Transport Canada Airworthiness Directive Pending.

2. MATERIAL INFORMATION

A. Parts Required Per Aircraft

(1) Detailed Parts List:

Quantity

Per Aircraft

Part Number Description Remarks

1 81151169 ---101 Warning Label or operator manufactured

label 8DK4141 ---101

1 GC ---1010 ---24 ---5DV GCU
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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.

Existing

Part Number Description Qty. IC DC

New Part

Number PNC

81151169 ---101 N

--- Warning Label 1 N/A N/A or

8DK4141 ---101 N

GC ---1010 ---24 ---5DIII

or GCU 1 A SAL GC ---1010 ---24 ---5DV N

GC ---1010 ---24 ---5DII

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.

N/A Not Applicable.

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

(1) Either pull and clip circuit breakers required to isolate affected circuits or placard

and select aircraft electrical power to OFF. Obey all relevant WARNINGS and

CAUTIONS detailed in Maintenance Manual PSM 1 ---8 ---2 or PSM 1 ---82 ---2 or

PSM 1 ---83 ---2.

(2) Refer to Figure 1 and gain access to the flight compartment. Locate the #1 GCU

on the bottom shelf of the right DC circuit breaker console.

B. Procedure

Part 1 --- GCU Replacement

(1) Refer to PSM 1 ---8 ---2 Chapter 24 ---31 ---03 or PSM 1 ---83 ---2 Chapter 24 ---31 ---03

or PSM 1 ---82 ---2 TASK 24 ---31 ---16 ---000 ---801 and Figure 2 and remove existing

#1 GCU part number GC ---1010 ---24 ---5DII or GC ---1010 ---24 ---5III from the

bottom shelf of the right DC circuit breaker console.

(2) Refer to enclosed Phoenix Aerospace Inc. Service Bulletin #: 000331 ---1 and

PSM 1 ---8 ---2 Chapter 24 ---31 ---03 or PSM 1 ---83 ---2 Chapter 24 ---31 ---03 or PSM

1 ---82 ---2 TASK 24 ---31 ---16 ---400 ---801 and Figure 2 and install new GCU part

number GC ---1010 ---24 ---5DV to bottom shelf of the right DC circuit breaker

console.

Part 2 --- Label Installation

(1) Refer to PSM 1 ---8 ---2 Chapter 20 ---22 ---02 or PSM 1 ---83 ---2 Chapter 20 ---22 ---02

or PSM 1 ---82 ---2 TASK 20 ---22 ---02 ---400 ---801 and Figure 3 and remove and

replace existing electrical connector label 2431 ---GCU1 with new warning label

81151169 ---101.

(2) If the operator chooses to have the label made locally, do the steps that follow.

(a) Refer to Figure 4 and PSM 1 ---8 ---2 Chapter 20 ---22 ---06 or PSM 1 ---83 ---2

Chapter 20 ---22 ---06 or PSM 1 ---82 ---2 TASK 20 ---00 ---11 ---800 ---801 and

make the label.

(b) Identify label as 8DK4141 ---101.

(c) Refer to PSM 1 ---8 ---2 Chapter 20 ---22 ---02 or PSM 1 ---83 ---2 Chapter

20 ---22 ---02 or PSM 1 ---82 ---2 TASK 20 ---22 ---02 ---400 ---801 and Figure 3 and

remove and replace existing electrical connector label 2431 ---GCU1 with

new warning label 8DK4141 ---101.

C. Close Out

(1) Remove all tools and equipment from the work area.
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(2) Refer to PSM 1 ---8 ---2 Chapter 24 ---31 ---00 or PSM 1 ---83 ---2 Chapter 24 ---31 ---00

and do an operational test of the DC Generator System or PSM 1 ---82 ---2 TASK

24 ---31 ---00 ---720 ---801 and do a functional test of the DC Generator System.

(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.
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#1 GCU Location

Figure 1

GENERATOR CONTROL UNIT

GC ---1010 ---24 ---5DV

QTY: 1

LABEL

81151169 ---101

or

8DK4141 ---101

QTY; 1
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Removal/Installation of Generator Control Unit

Figure 2

A

B

B

A
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Label Location

Figure 3

WARNING LABEL

81151169 ---101

or

8DK4141 ---101
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Warning Label 8DK4141 ---101

Figure 4

1

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.

1

8DK4141 ---101
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