COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Piaggio P166 Series Aeroplanes AD/P166/27 Magnetic Compass Installation - Modification 2/64 Applicability: All P166 series in which the maximum compass deviation and/or change in deviation due to electrical interference exceeds the limits prescribed in ANO 108.2.7. Requirement: 1. Modify the wiring to the pitot heaters, compass lighting and radio system if necessary, to reduce the interference to acceptable limits. 2. Remove the compass from the windshield frame and relocate it on the flare shield. Compliance: Forthwith.