COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Pilatus PC-12 Series Aeroplanes AIRWORTHINESS DIRECTIVE For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/PC-12/27 and issues the following AD under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section. Applicability: PC-12 and PC-12/45 series aeroplanes with manufacturer serial numbers MSN 101 up to and including MSN 400. Requirement: 1. Insert Temporary Revision No 32 in the Pilot's Operating Handbook/Aircraft Flight manual (POH/AFM). 2. Install the flap system Primary Drive Unit field control panel and modify the flap control wiring in accordance with the Accomplishment Instructions of Pilatus PC- 12 service Bulletin 27-011 Revision 1 dated 26 January 2001. Temporary Revision No 32 may be removed from the POH/AFM following accomplishment of Requirement 2. Note: FOCA Switzerland AD HB 2001-070 refers. Compliance: For Requirement 1 - Remains unchanged as 'Before further flight after 14 February 2001'. For Requirement 2 - Within 50 hours time in service or 30 days after the effective date of this Directive, whichever occurs first. This amendment becomes effective on 21 February 2001. Background: The Swiss Federal Office for Civil Aviation (FOCA) has advised that during system maintenance it was found that certain failures of the flap system Primary Drive Unit motor contactor could result in uncommanded cycling of the flaps between 40º and selected positions. Investigation revealed that that current surges were being generated due to the motor coil power being removed after the field coil power was removed or reversed. These surges can cause the contactor to fail in the closed position which could cause cycling of the flaps. The original issue of this Directive required a Temporary Revision to be inserted in the POH/AFM which introduced limitations on operation of the flaps. COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES This amendment introduces a modification which provides terminating action for the POH/AFM flap operating limitations introduced by Temporary Revision 32. The original issue of this Directive became effective on 14 February 2001. Eugene Paul Holzapfel Delegate of the Civil Aviation Safety Authority 15 February 2001 The above AD is notified in the Commonwealth of Australia Gazette on 21 February 2001.