AD/DHC-8/84 - Angle of Attack Sensor (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 39.1 (1) of CAR 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-8/84 Angle of Attack Sensor 2/2002

Applicability: DHC-8 Aircraft Models 301, 311, 314 and 315, Serial Numbers 100 through 583 inclusive.

Requirement: 1. Determine if MOD 'J' has been incorporated in both right and left angle of attack (AOA) sensors, Part Number (P/N) 861CAB. If Mod 'J' has been incorporated in both AOA sensors, no further action is required.

2. Conduct an AOA sensor vane movement test, on each AOA sensor that does not have Mod 'J' installed, to evaluate sticking against both the upper and the lower vane travel end stops. Conduct the tests in accordance with the Accomplishment Instructions of Bombardier Alert Service Bulletin (ASB) A8-27-94 dated 25 October 2001.

If the gram gauge readings from both the upper and lower AOA sensor vane positions are less than 110 grams, the applicable AOA sensor vane does not require replacement.

3. If the test results of the gram gauge reading from either the upper or the lower vane position exceeds 170 grams, replace the applicable AOA vane in accordance with the above-referenced ASB.