COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Eurocopter AS 355 (Twin Ecureuil) Series Helicopters AD/AS 355/37 Tail Rotor Pitch Control Lever Expansion Pin 9/91 DM Applicability: All AS 355 helicopters versions E, F, F1, F2 and N. Requirement: Action in accordance with the Technical Requirements of DGAC TAD T91-138-043 (B). Note: Aerospatiale TSB 01-34 refers. Compliance: As specified in the Requirement Document with revised effective date of 10 July 1991. Background: One lug of the tail rotor gearbox control lever hinge yoke failed through incorrect assembly of the bushes on the expansion pin.