AD/CL-600/112 Main Landing Gear Torque Link Apex Pin (Cth)

AIRWORTHINESS DIRECTIVE

For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.001(1) of CASR 1998.  The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

Bombardier (Canadair) CL-600 (Challenger) Series Aeroplanes

AD/CL-600/112 Main Landing Gear Torque Link Apex Pin 8/2009

Applicability:

Bombardier Inc. Models:

CL-600-2C10 - serial numbers 10003 and subsequent.

CL-600-2D15 and CL-600-2D24 - serial numbers 15001 and subsequent.

Requirement:

1.    Inspection of the Torque Link Apex Joint – Applicable to CL-600-2C10 Serial Numbers 10003 through 10223, and CL-600-2D15 and CL-600-2D24 Serial Numbers 15001 through 15035, 15038, 15039 and 15042.

Perform a one-time detailed visual inspection and any required action(s) on the torque link apex joint in accordance with Part A of the Accomplishment Instructions in Bombardier Aerospace Service Bulletin (SB) 670BA-32-019, Revision A, dated 18 September 2008, or later revision approved by the Chief, Continuing Airworthiness, Transport Canada.

Inspection performed in accordance with the original issue of SB 670BA-32-019, dated 16 March 2006, satisfies the Requirement 1 of this AD.

Requirement 1 of this AD is not required if Requirement 2 of this AD has already been accomplished.

Requirement 1 of this AD is not required if Repair Engineering Order (REO) 670-32-11-0022 or Goodrich Service Concession Request (SCR) 0056-05 has been incorporated.

2.    Replacement of the Torque Link Apex Nut – Applicable to CL-600-2C10 Serial Numbers 10003 through 10239, and CL-600-2D15 and CL-600-2D24 Serial Numbers 15001 through 15057.

Replace or rework the apex nut in accordance with Part B of the Accomplishment Instructions in Bombardier Aerospace SB 670BA-32-019, Revision A, or later revision approved by the Chief, Continuing Airworthiness, Transport Canada.

Replace or rework performed in accordance with the original issue of SB
670BA-32-019, satisfies Requirement 2 of this AD.

3.    Prohibition of Installation of Certain Main Landing Gear Shock Strut Assembly -Applicable to CL-600-2C10 Serial Numbers 10003 and subsequent, and CL-600-2D15 and CL-600-2D24 Serial Numbers 15001 and subsequent.

a)    No replacement/spare main landing gear shock strut assembly (P/N
49000-11 through 49000-22) with a serial number in the range 0001 through 0284 (the serial number can start with MA, MAL or MA-) is permitted to be installed on any aircraft unless it has been reworked in accordance with Part B of the Accomplishment Instructions in Bombardier Aerospace SB
670BA-32-019, Revision A, dated 18 September 2008, or later revision approved by the Chief, Continuing Airworthiness, Transport Canada.

b)    No replacement/spare main landing gear shock strut assembly (P/N 49050-5 through 49050-10) with a serial number in the range 1001 through 1114 (the serial number can start with MA, MAL or MA-) is permitted to be installed on any aircraft unless it has been reworked in accordance with Part B of the Accomplishment Instructions in Bombardier Aerospace SB 670BA-32-019, Revision A, dated 18 September 2008, or later revision approved by the Chief, Continuing Airworthiness, Transport Canada.

Rework performed in accordance with the original issue of SB 670BA-32-019, satisfies Requirement 3 of this AD.

Note:  Transport Canada AD CF-2009-20 dated 1 May 2009.

Compliance:

For Requirement 1 - Within 900 flight hours after the effective date of this AD.

For Requirement 2 - Within 4,500 flight hours after the effective date of this AD.

For Requirement 3 - As of the effective date of this AD.

This Airworthiness Directive becomes effective on 30 July 2009.

Background:

There have been four reports of loose or detached main landing gear torque link apex pin locking plate and the locking plate retainer bolt.  This condition could result in torque link apex pin disengagement, heavy vibration during landing, damage to main landing gear components and subsequent main landing gear collapse.

Investigation has determined that incorrect stack-up tolerances of the apex joint or improper installation of the locking plate and apex nut could result in torque link apex pin disengagement.  This directive mandates inspection of the torque link apex joint and replacement of the torque link apex nut.

James Coyne
Delegate of the Civil Aviation Safety Authority

16 June 2009