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-2012-07

Issue Date 

 27 January 2012 

Number: CF- 2012-07 

Subject: Cockpit “Engine Fire, Check Fire Detect” Warning and “FUEL OFF” Handle Lights 

Failure to Reset 

Effective: 10 February 2012 

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

through 4373. 

Compliance: As indicated below, unless already accomplished. 

Background: There have been engine fires on DHC-8 Series 400 aeroplanes, where the “ENGINE 

FIRE, CHECK FIRE DETECT” warning and “FUEL OFF” handle lights failed to reset and 

remained illuminated after the fire was extinguished. An investigation has revealed that 

the existing engine fire/overheat detector assemblies “Advance Pneumatic 

Detectors (APD)” may fail to reset after activation due to permanent deformation of the 

detector switch diaphragm after being exposed to high temperatures. 

This abnormal condition of a continued engine fire indication in the cockpit, after the 

actual fire has been extinguished, is misleading and may influence the pilot’s decision to 

conduct a potentially hazardous “off-airport” landing, which is considered an unsafe 

condition that warrants mitigating action. 

To mitigate this potentially hazardous condition, Bombardier has issued multiple service 

bulletins (SBs) to replace all three affected APDs with new detector assemblies that are 

not susceptible to the subject diaphragm deformation when exposed to excessive heat. 

This Airworthiness Directive (AD) mandates the incorporation of Bombardier 

SBs 84-26-08A, 84-26-09A and 84-26-12A on the affected aeroplanes. 

Corrective 

Actions: 

Within 6000 flight hours or 30 months, whichever comes first, from the effective date of 

this AD, replace all three engine fire/overheat detector assemblies “APDs”, at both left 

and right hand side engine locations, as per the following instructions: 

Part I – Nacelle – Engine Primary Zone : 

Remove APD part number (P/N) 10-1098 and install APD P/N 10-1098-01, in 

accordance with Bombardier Aerospace SB 84-26-08 Rev. ‘A’, dated 12 May 2011, or 

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

Part II – Nacelle – Landing Gear Primary Zone : 

Remove APD P/N 10-1097 or 10-1097-01 and install APD P/N 10-1097-02, in 

accordance with Bombardier Aerospace SB 84-26-09 Rev. ‘A’, dated 12 May 2011, or 

later revisions approved by the Chief, Continuing Airworthiness, Transport Canada. 
No.

N° CF-2012-07 2/2 

Part III – Propeller Engine Controller : 

Remove APD P/N 10-1096, 10-1096-01 or 10-1096-02 (introduced per SB 84-26-10A,

with serial number of all numeric characters) and install APD P/N 10-1096-02 (with serial 

number of three alpha and four numeric characters), in accordance with Bombardier 

Aerospace SB 84-26-12 Rev.’A’, dated 13 December 2011, or later revisions approved 

by the Chief, Continuing Airworthiness, Transport Canada. 

Authorization: For the Minister of Transport, Infrastructure and Communities 

ORIGINAL SIGNED BY

Derek Ferguson 

Chief, Continuing Airworthiness 

Contact: A.K. Durrani, Continuing Airworthiness, Ottawa, telephone 613-952-4357, facsimile 

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