COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Short SC7 (Skyvan) Series Aeroplanes AD/SC7/12 Fin/Tailplane Attachment - Inspection 8/79 Applicability: All Skyvan series 3, 3A and 3M. Document: Short SB No. 55-53. Compliance: Within 100 hours time in service after 31 October 1979. Background: It has been reported to the manufacturer that bolts connecting the fin to tailplane have been found not fully tightened.