AD/S-76/52 Power Turbine Speed Trim Control Actuators 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/S-76/52.

Sikorsky S-76 Series Helicopters

AD/S-76/52 Power Turbine Speed Trim Control Actuators 7/2009

Requirement:

CANCELLED.

This AD is cancelled on 2 July 2009.

Background:

This unique Australian AD raised in 1988 against Sikorsky Alert Service Bulletin (ASB) 76-76-3 required an inspection of the power turbine speed trim control actuator for looseness caused by loss of torque on the bolt attaching the power turbine control actuator to the torque shaft.

Compliance was:

1.    Within 25 hours TIS or by 10 June 1988, whichever occurs first, inspect in accordance with Para. E2 of requirement document.

2.    At next inspection for issue of a maintenance release after 10 June 1988, or within 100 hours TIS after 10 June 1988, whichever occurs first, or if vertical movement in the power turbine control torque shaft is detected, inspect in accordance with Para. E3 of requirement document.

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

James Coyne
Delegate of the Civil Aviation Safety Authority

18 May 2009