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 33/4 Heater Installation 2/69 Applicability: All models fitted with Hanlon and Wilson heater-muffler P/N 8046-1. Requirement: Action in accordance with Beechcraft SI No. 0096-412. Compliance: Within 100 hours time in service after 14 February 1969 and thereafter at intervals not exceeding 100 hours time in service.