COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Short SD3-60 Series Aeroplanes AD/SD3-60/28 Horizontal Stabilizer - Rear Spar Web/Boom 7/88 DM Applicability: All models with S/Nos SH3601 to SH3691 and SH3694. Requirement: Action in accordance with Shorts SB SD360-55-16. Compliance: Unless already accomplished, prior to 31 July 1988 and thereafter as per Requirement Document until modified in accordance with Shorts SB SD360-55-12. Background: Testing on a horizontal stabilizer with service usage has shown failure of some rivets connecting the rear spar web to the booms.