COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Fokker F50 (F27 Mk 50) Series Aeroplanes AD/F50/64 Seat Rails Tapered Shims 5/94 Applicability: Model F27 Mk 050 Series aircraft, serial numbers 20103 through 20258. Requirement: Action in accordance with Fokker Service Bulletin F50-25-045. Note: RLD AD 94-033 (A) refers. Compliance: Prior to 1 November 1994. Background: The ageing of the tapered nylon shims that are installed under the seat rails from fuselage STA.14025 aft, may result in a reduction in strength of the seat rail attachments. This Directive requires the removal of the shims and the replacement of the current seat rail attachment bolts with shorter ones.