COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Short SD3-30 Series Aeroplanes AD/SD3-30/37 Elevator Control Torque Tube Bearing Housing 3/99 Applicability: All SD3-30 aircraft. Requirement: Action in accordance with Shorts Mandatory Service Bulletin SD330-27-37. Compliance: Before 25 September 1999. This Airworthiness Directive becomes effective on 25 March 1999. Background: Experience shows that existing bolts securing the elevator control torque tube bearing housing retaining plate to pilot's seat pedestal have been found loose; probably because of the significance of the structure has not been recognised during maintenance.