COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes AD/DHC-8/3 Propeller Autofeather System 2/89 Applicability: All DHC-8-100 series aeroplanes serial numbers 1 through 113 inclusive. Requirement: Action in accordance with Boeing Canada de Havilland Division SB 8-61-12 Revision A. Note: Transport Canada AD CF-88-12R2 and FAA AD 88-12-51 R1 refer. Compliance: Prior to 23 March 1989. Background: Transport Canada have advised that recent incidents have occurred where the propeller has inadvertently unfeathered following activation of the autofeather system. This could result in loss of altitude in critical flight regimes.