COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Brantly B-2 Series Helicopters AD/B-2/1 Tail Rotor Guard and Skid Assembly P/N B2-416 - Modification 12/60 Applicability: All model B-2. Document: Brantly SB No. 1. Compliance: Forthwith.