AD/DHC-8/118 Spoiler Lift Dump 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 (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes

AD/DHC-8/118 Spoiler Lift Dump Valves 4/2006

Applicability:

Bombardier Inc. DHC-8 Models 400, 401 and 402, serial numbers 4005, 4006, 4008 through 4015 and 4018 through 4052.

Requirement:

1.    Replace all spoiler lift dump valves that have a serial number in the range from 5164 through 5264 or from 5267 through 5279.

2.    Do not install spoiler lift dump valves with a serial number that is in the suspect range any aircraft unless the manufacturing defect has been corrected.  These corrected valves are identified with a serial number that includes the suffix ‘A’ (e.g. S/N 5164A).

Note:  Transport Canada AD CF-2001-44 refers.

Compliance:

1.    Within 30 days after the effective date of this AD, unless previously accomplished.

2.    After the effective date of this directive.

This Airworthiness Directive becomes effective on 13 April 2006.

Background:

The manufacturer of the spoiler lift dump valves has determined that a venting slot was omitted during the manufacture of a batch lot of solenoid armatures.  Although the affected spoiler lift dump valves passed acceptance test procedures and no problems have been observed with in-service aircraft, this defect has the potential to prevent the ground spoilers from deploying.

James Coyne
Delegate of the Civil Aviation Safety Authority

3 March 2006