AD/AL 250/6 Amdt 1 Power Turbine Governor Modification 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 250/6 Amdt 1.

Allison Turbine Engines - 250 Series

AD/AL 250/6 Amdt 1 Power Turbine Governor - Modification 6/2009

Requirement:

CANCELLED.

This AD is cancelled on 4 June 2009.

Background:

This unique Australian AD raised in 1970 against Allison Commercial Engine Bulletin (CEB) 250 CEB-22 or -77 required a modification to provide protection for the power turbine in the event of N2 overspeed following a sudden loss of load.

Compliance was:  Before 1 July 1970.

This AD has been sufficiently promulgated for the affected engine 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