AD/CL-600/104 Inboard Flap Actuator (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-600/104 Inboard Flap Actuator 1/2009

Applicability:

Bombardier Inc. CL-600-2B19 aircraft.

Requirement:

Amend the Transport Canada approved maintenance schedule by incorporating the new inspection requirements of CMR Number C27-50-300-01, as introduced by Temporary Revision (TR) 2A-41 of Canadair Regional Jet Maintenance Requirements Manual (MRM), Appendix A, Certification Maintenance Requirements (CMR).

Note:  Transport Canada AD CF-2008-33 dated 5 November 2008 refers.

Compliance:

Within 30 days after the effective date of this AD.

Initial compliance with the new CMR task shall be carried out in accordance with the Phase-In Schedule detailed in TR 2A-41.

This Airworthiness Directive becomes effective on 15 January 2009.

Background:

During the acceptance test procedure of returned inboard flap actuators an excessive wear condition was identified regarding endplay between the flap actuator and ball screw.  Excessive wear of the screw and ball nut could potentially lead to a flap system jam.  A TR has been made to the Bombardier CL-600-2B19 Maintenance Requirements Manual Appendix A, CMR to ensure that unacceptable wear on the nut and ball screw is detected and corrected.

James Coyne
Delegate of the Civil Aviation Safety Authority

27 November 2008