COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Pilatus PC-12 Series Aeroplanes AD/PC-12/4 Propeller De-Icing Controller 12/96 Applicability: This Directive is applicable to PC-12 aeroplanes serial numbers 101 through 153 inclusive, equipped with Propeller De-icing Controller (PDIC) part number 968.29.13.223 (BFG 4E3163-1). Requirement: Inspect the PDIC to determine the modification status and, if necessary, replace the PDIC in accordance with Pilatus Aircraft Ltd PC-12 Service Bulletin (SB) 30-002 dated 16 September 1996. Note: FOCA Switzerland AD HB 96-416 refers Compliance: Either concurrent with the incorporation of Pilatus Aircraft Ltd SB 30-001 dated 20 December 1995 (Modification to the Anti-icing and De-icing Systems) or prior to 31 January 1997, whichever is later. This Airworthiness Directive becomes effective on 7 November 1996. Background: The Swiss Federal Office for Civil Aviation (FOCA) has advised that a potential for an Electromagnetic Interference (EMI) induced failure of the PDIC may exist. This condition, if not corrected, could cause incorrect operation of the PDIC and/or nuisance fault warnings. This Directive requires an inspection to determine the serial number and modification status of the PDIC and, if necessary, the installation of a modified PDIC with improved EMI protection.