AIRWORTHINESS DIRECTIVE For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/SD3-60/53 Amdt 3 and issues the following AD under subregulation 39.1 (1) of CAR 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 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. Short SD3-60 Series Aeroplanes AD/SD3-60/53 Amdt 4 Engine Mounting Tubes and Fittings 3/2003 Applicability: All SD3-60 aircraft that have not yet complied with Shorts Service Bulletin (SB) SD330- 71-18 or which are currently required to perform the 6 month repeat inspections in accordance with SB SD330-71-18 original issue, Revision 1, Revision 2, or Revision 3. Note: All aircraft that have complied with a previous issue of this Directive and determined that no corrosion exists, or have replaced all corroded engine tube sub- assemblies in accordance with Part B of a previous Requirement document, are not required to comply with Amendment 4 of this Directive. Requirement: Action in accordance with Shorts Service Bulletin SD360-71-20 or SD360-71-20 Revision Note: The Requirement document covers information contained in Service Information Letter 203, which will be cancelled. Compliance: Unless in compliance with the previous issue of this Directive, accomplish before 31 May 2003 or at the next required repeat inspection in accordance with SB SD330-71-18 original issue, Revision 1, Revision 2, or Revision 3; whichever occurs first. This Amendment becomes effective on 20 March 2003. Background: The manufacturer received reports of corrosion on the internal surface of the engine mounting tubes, tube end fittings, taper pins, and also on the foot fittings. Amendment 1 corrected fastener information in accomplishment instructions. Amendment 2 corrected ambiguities and errors in the Requirement document. Amendment 3 introduced a new Requirement document which superseded SB SD360-71- 18 at all issues. Short SD3-60 Series Aeroplanes AD/SD3-60/53 Amdt 4 (Continued) Amendment 4 is issued in response to a revision of the Requirement document which provides additional information on inspection for damage to the taper pin holes and installation of the taper pins. Amendment 3 of this Airworthiness Directive became effective on 28 November 2002. Amendment 2 of this Airworthiness Directive became effective on 23 March 2000. Amendment 1 of this Airworthiness Directive became effective on 22 April 1999. The original issue of this Airworthiness Directive became effective on 25 March 1999. David Alan Villiers Delegate of the Civil Aviation Safety Authority 31 January 2003 The above AD is notified in the Commonwealth of Australia Gazette on 26 February 2003.