AD/T53/8 Second Stage Power Turbine Rotor Disc Rework 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/T53/8.

AlliedSignal (Lycoming) Turbine Engines - T53 Series

AD/T53/8 Second Stage Power Turbine
Rotor Disc - Rework 8/2009

Requirement:

CANCELLED.

This AD is cancelled on 30 July 2009.

Background:

This unique Australian AD was originally raised in1973 and again in 1986 (with no changes) against Lycoming Overhaul Modification Bulletin (OMB) No. 0041 Rev 3 and AD/LYC-T/9B requiring rework to reduce stress concentrations at power turbine bolt holes by increasing corner radii and removing corrosion.

Compliance was prior to installation in an aircraft following next reconditioning completed after 31 July 1973.

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

19 June 2009