Transport Transports 

Canada Canada

 TP 7245E

 

AIRWORTHINESS DIRECTIVE

The following airworthiness directive (AD) may be applicable to an aircraft which our records indicate is registered in your name. ADs are issued pursuant to Canadian 

Aviation Regulation (CAR) 521 Division X. Pursuant to CAR 605.84 and the further details of CAR Standard 625, Appendix H, the continuing airworthiness of a Canadian registered aircraft is contingent upon compliance with all applicable ADs. Failure to comply with the requirements of an AD may invalidate the flight authorization of the aircraft. Alternative means of compliance shall be applied for in accordance with CAR 605.84 and the above-referenced Standard. 

This AD has been issued by the Continuing Airworthiness Division (AARDG), National Aircraft Certification Branch, Transport Canada, Ottawa, telephone 613 952-4357.

Pursuant to CAR 202.51 the registered owner of a Canadian aircraft shall, within seven days, notify the Minister in writing of any change of his or her name or address. 

To request a change of address, contact the Civil Aviation Communications Centre (AARC) at Place de Ville, Ottawa, Ontario K1A 0N8, or 1-800-305-2059, or www.tc.gc.ca/civilaviation/communications/centre/ address.asp 

24-0022 (01-2005)

1/2 No.

CF-2012-03

Issue Date 

 11 January 2012 

Number: CF- 2012-03 

Subject: Electrical Power – Wire Chafing within the Alternating Current Contactor Box 

Effective: 26 January 2012 

Applicability: Bombardier Inc. DHC-8 Aeroplane Models 400, 401 and 402, Serial Numbers 4001 

and subsequent. 

Compliance: As indicated below, unless already accomplished. 

Background: There has been one (1) reported in-service incident where the propeller de-icing system 

became unavailable due to burnt/chafed wires within the Alternating Current Contactor 

Box (ACCB). There has also been a number of additional minor events of wires found 

chafed within ACCBs. 

An investigation revealed that inadequate clearance between the wires and metallic 

structure within the ACCB could cause chafed wires. 

Damaged, chafed or loose wiring within an ACCB could affect the operation of the 

windshield heater, ice detector, angle of attack (AOA) vane heater, pitot probe heater, 

engine intake heater or propeller de-icing system. Loss of one of these systems could

adversely affect the aeroplane’s flight characteristics in icing conditions. 

This Airworthiness Directive (AD) mandates the inspection and rectification of the wiring 

installation within each ACCB. 

Corrective 

Actions: 

Part I – Applicable to Aeroplane Serial Numbers 4001 through 4354 and 4356

through 4366. 

Within 6000 hours air time or 36 months, whichever occurs first, from the effective date of 

this AD, inspect and rework the ACCB in accordance with the Accomplishment 

Instructions in the applicable Bombardier Service Bulletins (SB) listed below, or later 

revisions approved by the Chief, Continuing Airworthiness, Transport Canada. 

Service Bulletin Date 

84-24-47 Revision A 14 September 2011 

84-24-48 Revision A 14 September 2011 

84-24-49 Revision A 14 September 2011 

84-24-50 Revision A 14 September 2011 

Inspection and rework of the ACCB in accordance with the Initial Issue of the 

above-mentioned Service Bulletins satisfies the requirements of Part I of this AD. 
No.

N° CF-2012-03 2/2 

Part II – Applicable to Aeroplane Serial Numbers 4001 and subsequent. 

As of the effective date of this AD, no person may install an ACCB with the following 

combination of part numbers and series on any aeroplane: 

Part Number Series 

1152130-6 1, 2, 4 

1152148-6 1, 2, 4, 5 

1152090-6 1, 2, 4 

1152124-6 1, 2, 4, 5 

Authorization: For the Minister of Transport, Infrastructure and Communities 

ORIGINAL SIGNED BY

Derek Ferguson 

Chief, Continuing Airworthiness 

Contact: Robert Farinas, Continuing Airworthiness, Ottawa, telephone 613-952-4357, facsimile 

613-996-9178 or e-mail CAWWEBFeedback@tc.gc.ca or any Transport Canada Centre.