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-2013-19

Issue Date 

 18 July 2013 

Number: CF-2013-19 

Subject: Main Landing Gear Stabilizer Brace – Over-Torque and Insufficient Greasing of 

Lock Link Apex Joint 

Effective: 31 July 2013 

Applicability: Bombardier Inc. model DHC-8-400, -401 and -402 aeroplanes, serial numbers 4001 

through 4454. 

Compliance: Within 1000 hours air time or 6 months, whichever occurs first, from the effective 

date of this AD, unless already accomplished. 

Background: There have been two reported in-service incidents where one side of the main landing 

gear (MLG) did not achieve down-lock resulting in a gear unsafe indication. In both 

cases, the MLG was ultimately extended and down-lock was achieved through the use of 

the alternate extension system or by cycling the MLG. The investigation revealed that in 

both cases, the MLG stabilizer brace lock linkages were insufficiently greased and the 

lock linkage attachment bolts were over-torqued. 

Failure to extend and down-lock the MLG could adversely affect the safe landing of the 

aeroplane. 

This AD mandates the inspection, rectification as required, and lubrication of both MLG 

stabilizer brace lock link apex joints. 

Corrective 

Actions: 

A. Inspect both MLG stabilizer brace lock link apex joints for clearance in accordance 

with Bombardier Service Bulletin (SB) 84-32-121, Initial Issue, dated 27 May 2013, or 

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

1. If the clearance gap is 0.001 inches (0.025 millimeters) or greater, proceed to 

Part B of this AD. 

2. If the clearance gap is less than 0.001 inches (0.025 millimeters), rectify in 

accordance with the accomplishment instructions of the above-mentioned SB. 

Proceed to Part B of this AD. 

If the clearance gap cannot be rectified in accordance with the accomplishment 

instructions of the above-mentioned SB, contact the Bombardier Technical Help 

Desk for an approved repair. The approved repair must specifically reference this 

AD. Proceed to Part B of this AD after incorporation of the approved repair. 

B. Lubricate the MLG stabilizer brace lock link apex joint in accordance with the 

accomplishment instructions of the above-mentioned SB. 
No.

N° CF-2013-19 2/2 

Note: Completion of this AD does not alleviate the requirement to comply with the 

existing MRB task number 320001-201. 

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 AD-CN@tc.gc.ca or any Transport Canada Centre.