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-2/2 Tail Rotor Drive - Modification 12/60 Applicability: All model B-2 prior to S/Nos. 32. Document: Brantly SB No. 2. Compliance: Forthwith.