AD/AL 250/45 Power Turbine Inner and Outer Coupling Shaft Replacement 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 250/45.

Allison Turbine Engines - 250 Series

AD/AL 250/45 Power Turbine Inner and Outer
Coupling Shaft - Replacement 6/2009

Requirement:

CANCELLED.

This AD is cancelled on 4 June 2009.

Background:

This unique Australian AD raised in 1981 against  Allison Commercial Engine Bulletin (CEB) 250-C20B CEB-A-1173, 250-B17B CEB-A-1138, 250-C28B
CEB-A-72-2055 and 250-C30 CEB-A-72-3049, as appropriate, required replacement of power turbine inner and outer coupling shafts that may not have had the optimum seal fit which could have led to major shaft distress.

Compliance was:  Within 100 hours TIS after 31 July 1981.

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

James Coyne
Delegate of the Civil Aviation Safety Authority

24 April 2009