AD/AL 250/14 Compressor Wheels, Glass Bead Peening 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 250/14.

Allison Turbine Engines - 250 Series

AD/AL 250/14 Compressor Wheels, Glass Bead Peening 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-106 required glass bead peening of engine compressor blades to increase resistance to fatigue.

Compliance was:  Before installation in an aircraft following next overhaul completed after 1 December 1970.

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