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-12/19 Flap Inboard Attachment Fittings 9/99 Applicability: PC-12 and PC-12/45 aircraft, serial numbers MSN 101 up to and including MSN 300. Requirement: Modify the flap inboard attachment fittings in accordance with Pilatus PC-12 Service Bulletin No. 57-004 dated Jun 11, 1999. Note: FOCA Switzerland AD HB 99-353 refers. Compliance: Within 5 months of the effective date of this Airworthiness Directive. This Airworthiness Directive becomes effective on 9 September 1999. Background: During static testing, it was found that under maximum loading conditions the existing flap attachment fitting could buckle.