COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Pilatus Porter PC-6 Series Aeroplanes 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 39.1 (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 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. AD/PC-6/45 Fuel Return Line Check Valve 10/2000 Applicability: Pilatus PC-6 Porter aircraft, serial numbers 001 - 932 inclusive. Requirement: Carry out a once only inspection of the fuel return line check valve to determine that it is correctly located on the left hand side of the aircraft behind Frame 1 in accordance with Pilatus Service Bulletin PC-6 No. 179. If the check valve is correctly located, no further action is required. If the check valve is not correctly located, re-locate it in accordance with Pilatus Service Bulletin PC-6 No. 135 before further flight. Note: FOCA AD HB 2000-336 also refers. Compliance: No later than 15 January 2001. This Airworthiness Directive becomes effective on 5 October 2000. Background: This Directive is prompted by advice the fuel return line check valve installed on some Pilatus Porter aircraft may not be located correctly. The Directive requires a once only inspection of the check valve to ensure it complies with the aircraft's type design and to relocate it if necessary. Eugene Paul Holzapfel Delegate of the Civil Aviation Safety Authority 16 August 2000 The above AD is notified in the Commonwealth of Australia Gazette on 6 September 2000.