Revision ‘A’ 22 Feb 2013

DHC-8 (DASH 8)

SERVICE BULLETIN 8-33-56

Lights - Exterior, Taxi Lights - Introduction of Nose Gear Downlock

(NGDLK) Permissive Taxi Light Circuit to Eliminate Possibility of False

Indication (NG ALT DLK IND) - ModSum 8Q101968

NOTE: The initial issue of this service bulletin is not posted on RACS and was

issued to one customer for “release to service” of verification aircraft

serial number 342.

This page transmits Revision ‘A’ of Service Bulletin 8-33-56, pages 1 thru 10

dated 22 Feb 2013.

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

- the In-Service part of the Effectivity section is revised to include all DHC-8

aircraft s/n’s (003 thru 672). Was limited to only s/n 342

- the Reason section is revised to make an editorial change.

Was “EDI”, now “EDIS”

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

bulletin.

- the Job Set-Up section is revised to make editorial changes that follow in two

steps.

Was “sht”, now “sheet”

- the Procedure section is revised to make a few editorial changes that follow in

various steps:

Was “sht”, now “sheet”

Was “Connect / terminate”, now “Connect and/or terminate”

Was “a” now “an”

Was “turn”, now “rotate”

step (3) is deleted

step (6) is revised to provide details on how to do a continuity check and

provide a maximum resistance limit
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.

Remove the initial issue of Service Bulletin 8-33-56 and replace with attached.

Previous issue(s) of Service Bulletin 8-33-56

Initial issue - Pages 1 thru 8 dated 11 Feb 2013
D

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SERVICE BULLETIN

Customer

Support

ATA SYSTEM: 3341 NUMBER: 8-33-56

BOMBARDIER AEROSPACE REGIONAL AIRCRAFT CONSIDER THIS

SERVICE BULLETIN TO BE PARTICULARLY SIGNIFICANT AND

URGES OPERATORS TO PROMPTLY EVALUATE THE CONTENTS

SUBJECT: Lights - Exterior, Taxi Lights - Introduction of Nose Gear Downlock

(NGDLK) Permissive Taxi Light Circuit to Eliminate Possibility of

False Indication (NG ALT DLK IND) - ModSum 8Q101968

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 Mod 8/1519

incorporated.

Verification: ModSum 8Q101968 has been installed on DHC-8 Aircraft

Model 311 Serial Number 342.

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
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B. Reason

Problem: One operator has recently experienced an incident and reported that the

emergency downlock indication system (EDIS) had given false “down and

locked” indication.

Cause: Analysis of the EDIS indicates that a false indiction, regardless of the

condition of the landing gear, can be caused by a failure of the photo

transistors or wiring, or the presence of alternate light source.

Solution: This service bulletin introduces ModSum 8Q101968.

It introduces wiring modification to inhibit the illumination of taxi light when

nose landing gear is in transition or retracted.

An intermediate relay circuit is introduced to be put in between the taxi

light switch and the taxi light relay wiring. A new connection to the

advisory light system and PSEU is introduced.

C. Description

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

follow:

- the aircraft electrical system is de-energized

- lock pins are installed through each main gear and main gear door mechanism

- the nose gear ground lock is engaged

- the terminal connector from the Main and Auxiliary batteries are disconnected

- panels are removed from the wardrobe to gain access to relay panel No.1, No.2 and

No.3 as applicable

- relay panels are released (as required) to provide access to the wiring and relay

base plates

- access is gained to the under floor cross over disconnect

- relay p/n X-D4N is installed and label p/n CSP255-3344-K2 is applied to relay panel

No.1 or No.3 as applicable

- cable assembly 8Z0377-011 is installed and terminated

- a continuity check is accomplished to verify compliance with the electrical

schematic view

- the battery terminal connector is re-connected to the Main and Auxiliary battery
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- a taxi light NGDLK functional test procedure is completed

- all remove access panels and floor panels are re-installed and closed

- close out.

D. Compliance

Bombardier Inc. highly recommend that ModSum 8Q101968 be incorporated at

the earliest opportunity unless otherwise directed by the operator’s airworthiness

authority.

A Transport Canada Airworthiness Directive is Pending.

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).

F. Manpower

It will take an estimated 8 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 1.00

Procedure 5.50

Test / RTS 0.50

Close-Out 1.00

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
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G. Material - Price and Availability

The parts necessary to do this service bulletin are available through the Customer

Accounts Service Team at Bombardier Aerospace Regional Aircraft division.

Operators should submit a purchase order specifying aircraft serial number(s) to:

Bombardier Aerospace

Customer Accounts Services Team (Mail Stop N11-32)

123 Garratt Blvd.

Toronto

Ontario

Canada M3K-1Y5

Facsimile: (416) 375-3060

Telephone: (416) 375-3920

Kit Number Description

8MK4645-001 Kit - Taxi Light Redesign to Eliminate

Possibility of False Indication

H. Tooling - Price and Availability

None

I. Weight and Balance

None

J. Electrical Load Data

1. Direct Current (DC) Load Change

Item Equipment Bus Bus Code Load Operating

Condition

33Q7 Relay Taxi

Light

28 V DC

Left Main

Bus

G1 +0.06 Amps Taxi
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2. Alternating Current (AC) Load Change

Item Equipment Bus Bus

Code

Phase VA PF Load Operating

Conditions

N/A N/A N/A N/A N/A N/A N/A N/A N/A

K. Publications Affected

Aircraft Operating Data Manual PSM 1-81-1 and .......................

PSM 1-82-1 and

PSM 1-83-1

Flight Manual PSM 1-81-1A and ......................................

PSM 1-82-1A and

PSM 1-83-1A

PSM 1-82-1B and

PSM 1-83-1B

Maintenance Manual PSM 1-8-2 and ................................

PSM 1-82-2 and

PSM 1-83-2

Wiring Diagrams Manual PSM 1-8-2W and ............................

PSM 1-82-2W and

PSM 1-83-2W

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

related data that follows:

DRAWING SHEET REV

8MK4645 1 --

8Z0377 1 A

8Z0377 2 A

8Z0377 3 A
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ModSum 8Q101968 Rev. ‘B’

PCA 06824 Revision 1 (for internal reference only)

Bombardier Inc. Modification 8/1519 (Service Bulletin 8-33-28 revision ‘A’).

Transport Canada Airworthiness Directive is Pending.

2. MATERIAL INFORMATION

A. Parts Required Per Aircraft

(1) Modification Kit 8MK4645-001

(2) Detailed Kit Content:

Quantity Per Kit

-001

Part Number Description Remarks

100 MS3367-1-9 Tie Wrap Quantity may be

surplus to account for losses

1 CSP255-3344-K2 Label

1 X-D4N Relay

1 8Z0377-011 Cable Assembly For A/C Post Mod

8/1519

Ref 8Z0377 Drawing -Taxi LT

Wiring

Drawing only

B. Parts Required to Modify Spares

None

C. Special Tools and Equipment Required

None
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D. Existing Parts Accountability

None

3. ACCOMPLISHMENT INSTRUCTIONS

A. Job Set-Up

(1) Placard and select all aircraft electrical power to OFF. Obey all relevant

WARNINGS and CAUTIONS detailed in Maintenance Manual PSM 1-8-2, 1-82-2

or 1-83-2 Chapters 12 and 24.

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

door mechanism.

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

(4) Disconnect the terminal connector from the Main and Auxiliary battery.

(5) For Dash 8 Series 100 and 200, remove panels from the wardrobe to gain

access to relay panels No. 1 and 2 (refer to drawing 8Z0377 sheet 3 for

location).

(6) For Dash 8 Series 300, remove panels from the wardrobe to gain access to relay

panels No. 2 and 3 (refer to drawing 8Z0377 sheet 3 for location).

(7) Remove bulkhead assembly wing 82523363 (the panel located outboard of the

forward PA handset) for access to relay panel 3 and PSEU rear tray.

(8) Remove and keep fasteners securing relay panel No. 1. Pull panel out far

enough to gain access to the wiring and relay base plates. Support and hang

the relay panel temporarily with tie wraps or equivalent.

B. Procedure

(1) Install relay p/n X-D4N to relay panel using supplied fasteners (refer to

applicable view of relay panel given on drawing 8Z0377 sheet 3).

(2) Apply label CSP255-3344-K2 to panel next to new relay. Make sure to wipe

clean the affected area on the relay panel before applying label.

(3) Deleted.
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(4) Install and/or terminate cable assembly 8Z0377-011 to agree with all of the

NOTES and the detail views given on drawing 8Z0377 sheet’s 2 and 3.

(a) Make sure to assemble the ident sleeves DSC347-1/2-2.00-9 &

DSC347-1/4-2.00-9, splices M81824/1-2, contact sockets 002-3261-000,

pins, relay, relay base and all other related hardware called up on the drawing

to new cable assembly as required.

(b) For crimping of electrical contacts refer to AMM Chapter 20-45-09 for 100 and

300 series aircraft or AMM TASK 20-45-09-02 for 200 series aircraft.

(c) For electrical bonding, refer to AMM Chapter 51-80-00 for 100 and 300 series

aircraft or AMM TASK 51-80-00-02 for 200 series aircraft.

(d) For splicing , refer to AMM Chapter 20-45-07 for 100 and 300 series aircraft or

AMM TASK 20-45-07-02 for 200 series aircraft.

(e) For identification of wires and components, refer to AMM Chapter 20-45-13 for

100 and 300 series aircraft or AMM TASK 20-45-13-02 for 200 series aircraft.

(5) Secure new cable assembly 8Z0377-011 to existing cable assemblies using tie

wraps MS3367-1-9 where additional support is required.

(6) Do a continuity check of the new and the existing wires shown on drawing

8Z0377 sheet 2 as follows:

(a) Connect the negative (-) lead of an ohmmeter to one end of a wire to be tested

and the positive lead (+) of an ohmmeter to the opposite end of the same wire.

(b) For long distance checking of a wire connect one end of a wire to be tested to

the positive lead (+) of an ohmmeter and the other end of the wire to a ground

point with a jumper wire. Connect the negative lead (-) of an ohmmeter to the

same ground point.

(c) A complete circuit (or closed circuit) from point to point must exist through

each wire. The maximum resistance permitted between the two points in a

closed circuit is 5 ohms.

NOTE: Continuity of a circuit is affected when a diode is part of a circuit. When

checking continuity across a diode the electrical polarity must be

observed.

Continuity of a circuit is also affected when a circuit contains computer

controllers, valves, relays, coils, circuit breakers, etc. Temporarily

disconnect or remove all the electrical components connected to the

wires to be tested. Reconnect components after testing.

(d) If the resistance exceeds 5 ohms from point to point (open circuit) recheck the
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new and reworked wiring to make sure it is terminated to the correct

connection, check the wiring for mechanical damage, loose connector parts,

bent pins and corrosion. Correct the deficiency.

(7) Connect the battery terminal connector to the Main and Auxiliary battery. Make

sure to safety the battery terminal connector with copper lockwire.

CAUTION: DO NOT APPLY HYDRAULIC POWER DURING THE FUNCTIONAL

TEST.

(8) Do the TAXI LIGHT INTERLOCK functional test procedure given on drawing

8Z0377 sheet 1.

C. Close Out

(1) Remove all tools, equipment and unwanted materials from the work area.

(2) Close all access panels that were previously removed to do this ModSum.

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

regulatory requirements in the applicable logbook(s). If only part of this

ModSum is completed, use only this service bulletin number as reference and

detail exact limit of work completed. 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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This Page Intentionally Blank

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