COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Sikorsky S-76 Series Helicopters AD/S-76/36 Fuselage - Engine Compartment Centre Firewall - Inspection of No. 1 Tail Drive Shaft for Adequate Clearance Applicability: All model S-76A Helicopters. Requirement: Sikorsky Alert S.B. 76-53-24. Sikorsky CBT-TP-84-098. Compliance: Unless already accomplished, before further flight after 12 February 1985. Background: A report indicates No. 1 section tail rotor drive shaft became severed due to interference with doubler P/N 76070-20057-101. 3/85 TX