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. 

URGENT URGENT URGENT URGENT URGENT URGENT URGENT URGENT URGENT

TRANSPORT CANADA EMERGENCY AIRWORTHINESS DIRECTIVE 

PLEASE FORWARD IMMEDIATELY TO THE PERSON RESPONSIBLE FOR THE 

OPERATION AND MAINTENANCE OF YOUR AIRCRAFT

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-2012-08

Issue Date 

 30 January 2012 

Number: CF-2012-08 

Subject: Power Lever Friction Brake Assembly Discrepancy

Effective: 30 January 2012 

Applicability: Bombardier Inc. DHC-8 Aeroplane Models 102, 103, 106, Serial Numbers 003 

through 039 

Compliance: As indicated below, unless already accomplished.

Background: During maintenance, it was discovered that it was possible to inadvertently move the 

power levers through the flight idle gate into the beta range. An investigation revealed

that an un-chamfered leaf spring in the friction brake may contact the power lever latch

when the friction adjusting knob is fully loosened. This can result in the lifting of the

power lever latch and allow the power levers to pass through the flight idle gate without 

lifting the triggers. 

Further investigation also determined that an un-chamfered spring installation with a 

pre-Service Bulletin (SB) 8-76-2 (Mod 8/0443) friction brake nut can further increase the 

possibility of allowing power levers to pass through the flight idle gate without lifting the 

triggers, when the friction adjusting knob is fully loosened. 

The above discrepancies, if not corrected, may result in an unsafe condition where both 

engines can inadvertently be operated in beta mode during flight. 

In order to address this potentially unsafe condition, Bombardier has issued: 

• Alert Service Bulletin (ASB) A8-76-32 requiring operators to inspect the springs and 

chamfer the springs as applicable, and 

• SB 8-76-02 Rev. A to replace the pre-SB 8-76-2 (Mod 8/0443) original friction brake 

nut with a new friction brake nut with larger shoulders. 

This Airworthiness Directive (AD) is being issued to mandate compliance with 

Bombardier ASB A8-76-32 and SB 8-76-02 Rev. A requirements on the affected 

aeroplanes. 
No.

N° CF-2012-08 2/2 

Corrective 

Actions: 

Part I

Within 50 flight hours or 10 days, whichever occurs first, from the effective date of this 

AD, perform an inspection of the friction leaf spring assembly and rework as applicable, 

in accordance with Bombardier ASB A8-76-32, dated January 27 2012, or later revisions 

approved by the Chief, Continuing Airworthiness, Transport Canada. 

Part II

Within 50 flight hours or 10 days, whichever occurs first, from the effective date of this 

AD, install a new friction brake nut, in accordance with Bombardier SB 8-76-02 Rev. A,

dated January 25 2012, or later revisions approved by the Chief, Continuing 

Airworthiness, Transport Canada. 

Compliance with the initial issue of SB 8-76-2 (Mod 8/0443), dated January 24 1986, 

meets the intent of Part II of this AD. 

Authorization: For the Minister of Transport, Infrastructure and Communities 

ORIGINAL SIGNED BY

Derek Ferguson 

Chief, Continuing Airworthiness 

Contact: Mr. 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.