COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Short SD3-60 Series Aeroplanes AD/SD3-60/37 Horizontal Stabiliser Attachment Lugs 6/93 Applicability: All SD3-60 aircraft with tailplanes which have accumulated 20,000 or more flights. Requirement: Modify the aircraft and ultrasonically inspect the forward and aft tailplane attachment lugs, upper and lower surfaces, in accordance with SB SD360-55-19. Note: SB SD360-55-19 has been classified mandatory by the UK CAA. Compliance: Before 29 July 1993. Reinspect at intervals of not more than 4000 flights. Background: The manufacturer has determined by continued testing that additional inspections are required on the horizontal stabiliser attachment lugs.