COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Robinson R22 Series Helicopters AD/R22/1 Amdt 1 Applicability: Model R22 Series. Main Rotor Blade 7/92 Requirement: Remove from service all main rotor blades with Serial Numbers 1 through 91. Note: FAA AD 80-11-07 Amdt 39-3834 refers. Compliance: Unless already accomplished; prior to 30 June 1992. Background: Delamination of the trailing edges and root end doublers of the main rotor blades may occur in normal service. Amendment 1 is raised to reflect the FAA requirement that the above affected main rotor blades be removed from service in order to prevent possible blade structural failure.