COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES DHC-2 (Beaver) Series Aeroplanes AD/DHC-2/31 Fuselage Station 228 Bulkhead 1/99 Applicability: All model DHC-2 Mk. I and Mk. II "Beaver" aircraft and Mk. III "Turbo Beaver" aircraft. Requirement: Inspect the rear fuselage bulkhead at station 228 in accordance with Bombardier Inc. de Havilland Service Bulletin 2/52 or TB/60, as applicable. If cracks are found, before further flight, replace the bulkhead, or repair the bulkhead in accordance with repair instructions from the manufacturer. Note: Transport Canada AD CF-98-38 refers. Compliance: Unless the initial inspection is already accomplished, before 1 December 1999; thereafter at intervals not to exceed 5 years. This Airworthiness Directive becomes effective on 28 January 1999. Background: Transport Canada received reports of cracks in the bulkhead at fuselage station 228 of three DHC-2 aircraft which had accumulated between 10,000 and 12,000 flight hours.