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. Avions de Transport Regional ATR 42 Series Aeroplanes AD/ATR 42/12 Main Landing Gear Wheels 8/2007 Applicability: Model ATR 42-300 and -320 aircraft, all serial numbers, without ATR Service Bulletin ATR42-32-0017 incorporated (Modification 1536 that introduces reinforced wheels ref. 500 6856-3). Requirement: Action in accordance with the requirements of DGAC AD 87-091-006(B) R1. Compliance: As specified in the Requirement document. This Airworthiness Directive becomes effective on 2 August 2007. Background: A report was received of the failure of the internal half rim radii of a main landing gear wheel during the acceleration stage of take-off. This Directive requires visual and NDT inspections of the affected wheels. David Villiers Delegate of the Civil Aviation Safety Authority 22 June 2007