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) 593. 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-2009-17

Issue Date 

 22 April 2009 

Number: CF-2009-17 

Subject: Revised Safe Life Limits for Airworthiness Limitation Items

Effective: 21 May 2009 

Applicability: Bombardier Inc. DHC-8 Aircraft, Models 400, 401 and 402, Serial Numbers 4001, 4003, 

4004, 4006, 4008 through 4227. 

Compliance: When indicated, unless already accomplished. 

Background: Certain main landing gear components have experienced premature failure during 

certification testing. Revision has been made to the DHC-8-400 Maintenance 

Requirements Manual, Airworthiness Limitation Items, to incorporate the revised safe life 

limits for the main landing gear lock actuator assembly, retraction actuator assembly rod 

end and piston, and the upper bearing in the main landing gear shock strut assembly. 

Failure of these components could adversely affect the structural integrity of the main 

landing gear. 

This directive is issued to ensure safe operation of the main landing gear during its 

service life. 

Corrective 

Actions: 

A. Main Landing Gear Structural Safe Life Limit Change – Applicable to DHC-8 

Aircraft, Models 400, 401 and 402, Serial Numbers 4001, 4003, 4004, 4006, 4008 

through 4210

Within 60 days after the effective date of this directive, amend the Transport Canada 

approved maintenance schedule by: 

1) Incorporating the revised safe life limit for the Upper Bearing, Part Number (P/N)

46114-1, as presented in Temporary Revision (TR), ALI-82 of Airworthiness 

Limitation Items (ALI) of the DHC-8-400 Maintenance Requirements Manual, 

PSM 1-84-7; and 

2) For aircraft that has accumulated more than 15,000 flight cycles, replace the 

Upper Bearing (P/N 46114-1) at the next “C” check or 20,000 flight cycles, 

whichever occurs first. 

B. Main Landing Gear System Safe Life Limits Change – Applicable to DHC-8

Aircraft, Models 400, 401 and 402, Serial Numbers 4001, 4003, 4004, 4006, 4008 

through 4227

Within 60 days after the effective date of this directive, amend the Transport Canada 

approved maintenance schedule by: 
No.

 N° CF-2009-17 2/2 

1) Incorporating the revised safe life limit for the Retraction Actuator Assembly Rod 

End (P/N P3A2750 and/or P3A2750-1), Retraction Actuator Assembly Piston 

(P/N 46570-5), Lock Actuator Cylinder Assembly (P/N 46601-1/-3) and Lock 

Actuator Assembly (P/N 46600-1/-3/-5/-7) as presented in TR, ALI-89 of ALI of 

the DHC-8-400 Maintenance Requirements Manual, PSM 1-84-7; and 

2) For the main landing gear retraction actuator assembly rod end that has

accumulated more than 9,850 flight cycles, replace the Rod End (P/N P3A2750 

and/or P3A2750-1) within the next 600 flight cycles. 

Note: Compliance in accordance with superseding TRs or later revisions of ALI of the 

DHC-8-400 Maintenance Requirements Manual, PSM 1-84-7, approved by 

Transport Canada also satisfy the requirements of this directive. 

Authorization: For Minister of Transport, Infrastructure and Communities 

Derek Ferguson 

Acting Chief, Continuing Airworthiness 

Contact: Mr. Anthony Wan, Continuing Airworthiness, Ottawa, telephone 613-952-4410, facsimile 

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