AD/OH-58/8 Amdt 1 - Main Rotor Mast Cracking (Cth)

COMMONWEALTH OF AUSTRALIA Civil Aviation Safety Regulations 1998 (CASR 1998)

CIVIL AVIATION SAFETY AUTHORITY   Regulation 39.001

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 repeals Airworthiness Directive (AD) AD/OH-58/8 and issues the following AD under subregulation 39.001 (1) of CASR 1998 and subsection 33 (3) of the Acts Interpretation Act 1901. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct an 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 Helicopter Textron Canada (BHTC) 206A-1 (OH-58A) Series Helicopters

AD/OH-58/8

Amdt 1

Main Rotor Mast Cracking   20/2015

Applicability:       This AD applies to all 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 2014-22-03. Compliance:   Unless previously accomplished, the required actions in FAA AD 2014-22-03 must

be performed within the compliance time specified in FAA AD 2014-22-03. The effective date of this AD is 25 September 2015.

Background:        This amendment to AD/OH-58/8 requires repetitive inspections (1200 hours TIS or

3 years, whichever occurs earlier) of the Main Rotor Mast for a crack and expands the mast inspection area. The AD also requires periodic overhaul (1200 hours TIS or

3 years, whichever occurs earlier) of the Main Rotor Mast Assembly and NDT Inspection of various Main Rotor Mast Assembly components.

This AD was prompted by two reported failures of the mast from corrosion-initiated fatigue cracking. The actions specified by this AD (with reference to FAA AD

2014-22-04) are intended to prevent failure of the mast and subsequent loss of control of the helicopter.

The initial issue of this AD required compliance with FAA AD 2012-14-11 which has now been superseded by FAA AD 2014-22-03.

Nicholas Ward
Delegate of the Civil Aviation Safety Authority

21 September 2015

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