Ad/Al 250/46 Amdt 1 - Power Turbine Governor (Bendix) - Inspection of Drive Shaft - 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 250/46 Amdt 1.

Allison Turbine Engines - 250 Series

AD/AL 250/46 Amdt 1 Power Turbine Governor
(Bendix) - Inspection of Drive Shaft 10/2009

Requirement:

CANCELLED.

This AD is cancelled on 24 September 2009.

Background:

This unique Australian AD raised in 1983 against Allison Commercial Engine Bulletin (CEB) 250-C18 212, Rev. 3, 250-C20, C20B, C20F, C20J CEB-1170, Rev.3, 250-C28B, C28C CEB 73-2018, Rev.3, 250-C30, C30P CDEB 73-3012, Rev. 3 required repetitive inspections of Power Turbine governor drive shaft for wear and condition of added epoxy bond.  This action follows manufacturer reports of excessive spline wear on the governor drive shaft.

Compliance was:  As per requirement document.

As the Alert status has been removed from the CEB by acceptance that a failed governor drive shaft, causing a possible N2 overspeed condition, can be corrected by pilot action through normal aircraft operating procedures, and given the extended period this AD has been promulgated, it is considered that this AD is no longer required.

James Coyne
Delegate of the Civil Aviation Safety Authority

14 August 2009