COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES SAAB SF340 Series Aeroplanes AD/SF340/7 Amdt 1 Power Turbine Speed Signal - Overspeed Protection 8/87 Applicability: SAAB 340A Aircraft. Requirement: Action in accordance with SAAB Service Bulletin SF 340-76-018. Note: Swedish Airworthiness Directive SAD NO. 1-021 refers. Effectivity: 31 July 1987. Background: This amendment has been raised to incorporate the final closing action for overspeed protection to prevent engine power turbine overspeed and with it the risk of uncontained engine failure. The amendment supersedes the FAA Telegraphic AD T86-10-51.