Ad/CL-600/118 - Bulkhead Check Valves (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-600/118 Bulkhead Check Valves 10/2009

Applicability:

Bombardier Inc. Model CL-600-2B19, Serial Numbers 7003 and subsequent.

Requirement:

Revise the Transport Canada approved maintenance schedule by incorporating the discard task, Task Number 21-51-21-13, for the bulkhead check valves, P/N 92E20-3 and 92E20-4.

This task was introduced by Temporary Revision (TR) 1-2-39, dated
12 December 2008, to the Maintenance Requirements Manual, CSP A-053, Part 1, Maintenance Review Board Report, Section 2, System and Powerplant Program.

Note:  Transport Canada AD CF-2009-31 dated 8 July 2009 refers.

Compliance:

Within 60 days after the effective date of this AD unless previously accomplished.

This Airworthiness Directive becomes effective on 24 September 2009.

Background:

Three cases of in-flight loss of cabin pressurization have been reported, resulting from failure of a bulkhead check valve in combination with failure of an air supply duct.

In addition to mandating inspection, rework and/or replacement of the air supply ducts, AD/CL-600/80 (Transport Canada AD CF-2003-05R1) mandated the incorporation of a 4,000 flight-hour repetitive inspection task for bulkhead check valves, Part Numbers (P/N) 92E20-3 and 92E20-4, into the approved maintenance schedule.  However, this repetitive inspection task has since been superseded by a 3,000 flight-hour periodic discard task for these bulkhead check valves.

This AD mandates revision of the approved maintenance schedule to incorporate the discard task for bulkhead check valves, P/N 92E20-3 and 92E20-4, and supersedes the instructions detailed in Corrective Actions, Part A, of Transport Canada AD
CF-2003-05R1, subsequently mandated by AD/CL-600/80.

James Coyne
Delegate of the Civil Aviation Safety Authority

14 August 2009