COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Short SC7 (Skyvan) Series Aeroplanes AD/SC7/14 Flap Mechanism Support Structure - Inspection and Modification Applicability: All models as referenced in Alert SB No. 27-A64, Rev. 4. Document: Short Alert SB No. 27-A64, Rev. 4. 9/79 Compliance: Unless already accomplished, within 50 hours time in service after 2 October 1979. Background: In service cracking has developed in some overseas operated Short SC7s in the support structure for the flap mechanism located in the centre section.