COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Partenavia P68 Series Aeroplanes AD/P68/37 Frame No. 1 12/91 Applicability: Model P68C and P68C-TC with serial numbers up to and including 392. Requirement: Action in accordance with the Technical Requirements of RAI AD 91-243. Note: Partenavia SB 84 refers. Compliance: Within 100 hours time in service after 12 December 1991. Background: Reports of cracks on frame No 1 around the nose landing gear attachment rivets.