AD/AL 250/33 Fourth Stage Compressor Wheel Retirement Cancelled (Cth)

AIRWORTHINESS DIRECTIVE

On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive AD/AL 250/33.

Allison Turbine Engines - 250 Series

AD/AL 250/33 Fourth Stage Compressor Wheel - Retirement 6/2009

Requirement:

CANCELLED.

This AD is cancelled on 4 June 2009.

Background:

This unique Australian AD raised in 1979 against Allison Commercial Service Letter (CSL) 250-C18 CSL-96 and Allison B15G TP CSL-36, as appropriate, required inspection and retirement of certain fourth stage compressor wheels following a reported failure due hardness of wheel above that specified.

Compliance was:  Within 100 hours TIS after 31 May 1979.

This AD has been sufficiently promulgated for the affected engines to have been inspected by now; therefore this AD is considered to be no longer required.

James Coyne
Delegate of the Civil Aviation Safety Authority

24 April 2009