AD/Hiller 12/42 Main Rotor Mast 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/HILLER 12/42.

Hiller UH-12 Series Helicopters

AD/HILLER 12/42 Main Rotor Mast 9/2009

Requirement:

CANCELLED.

This AD is cancelled on 27 August 2009.

Background:

This unique Australian AD raised in 1991 required a visual inspection of the main rotor mast at both ends of the two elongated collective control terminal pin slots following two reports of cracks being found in this area.

Compliance was prior to further flight unless accomplished within the previous 100 hours TIS, and thereafter at intervals not to exceed 100 hours TIS, and immediately upon the onset of any unusual vibration or stiffness or binding of the collective control.

Given the extended period this AD has been promulgated and that no record of this defect has been entered in the mandatory reporting system since the original occurrences in compliance with this AD, this AD is considered to be no longer required.

James Coyne
Delegate of the Civil Aviation Safety Authority

15 July 2009