COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Beechcraft 33 and 35-33 (Debonair/Bonanza) Series Aeroplanes AD/BEECH 33/39 Cabin Fresh Air Blower 12/91 Applicability: Model F33A with serial numbers CE-941 through CE-1555. Model F33C with serial numbers CJ-156 through CJ-179. Requirement: Action in accordance with the Technical Requirements of FAA AD 91-20-08 Amdt 39-8042. Note: Beech SB 2380 refers. Compliance: As specified in the requirement document with a revised effective date of 12 December 1991 for Australian registered aircraft. Background: Reports have been received of air blower housing attachment failures. This condition could lead to blower impingement on the flight control cables located below the blower. The effective date required by the FAA is extended by approximately one month.