AIRWORTHINESS DIRECTIVE
For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.001(1) of CASR 1998.  The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.
Bell OH-58A (206A-1) Series Helicopters
AD/OH-58/8
Main Rotor Mast Cracking
16/2012
 
Applicability:
Model OH-58A (Bell 206A-1) series helicopters, including AMT OH-58A and Osborne OH-58A.

Requirement:
Action in accordance with the technical requirements of FAA AD 2012-14-11.

Compliance:
As specified in the requirement document.

 
This Airworthiness Directive becomes effective on 7 August 2012.

Background:
This Directive requires inspections of the main rotor mast (mast) for a crack. This AD is prompted by two reported failures of the mast from corrosion-initiated fatigue cracking. The actions specified by this AD are intended to prevent failure of the mast and subsequent loss of control of the helicopter.

Rick Leeds
Delegate of the Civil Aviation Safety Authority
30 July 2012