COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Aerostar (Piper/Ted Smith) 600 and 700 Series Aeroplanes AD/TSA-600/33 Amdt 6 Applicability: All models. Main Landing Gear Torque Links 7/97 Requirement: 1. On each main landing gear torque link set, inspect the lugs at the junction of the links for fatigue cracks using the fluorescent dye penetrant method. 2. Unless already accomplished, replace the nut on the link connecting bolt with a castellated nut AN 310-6 using MS 24665-302 cotter pin. If the length of link connecting bolt does not permit installation of cotter pin, replace bolt with a NAS 6606-24D bolt. Note 1: FAA AD 93-13-08 Amdt 39-8621 and Aerostar Service Bulletin 746C refer. Note 2: Installation of improved torque links in accordance with Part II of Aerostar Service Bulletin 746C, constitutes terminating action for the Requirement 1 inspection of this Directive. Compliance: 1. At the next inspection for the issue of a maintenance release in the airframe category and at each subsequent inspection for issue of a maintenance release; until improved torque links are installed in accordance with Part II of Aerostar Service Bulletin 746C. 2. At the next inspection for the issue of a maintenance release in the airframe category. The compliance of the previous issue remains unchanged except for the additional information included in the Requirement 1 compliance statement. This Amendment becomes effective on 19 June 1997. Background: Reports have been received of cracks developing in the main landing gear torque links. Should the torque links fail during landing, directional control of the aircraft could be lost. Reports have also been received of stripped threads on the link connecting bolt shear nut. Fitment of castellated nuts will provide increased thread engagement and positive locking. Amendment 6 is issued to introduce terminating action for the repetitive inspection requirement, by aligning this Directive with the requirement of the related FAA AD. Amendment 5 of this Airworthiness Directive became effective on 15 September 1994. Amendment 4 of this Airworthiness Directive became effective on 31 July 1986. The original issue of this Airworthiness Directive became effective on 31 July 1984. COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES