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/F50/11 Wing Centre Section Cable Tray Blanking Plate 3/89 DM Applicability: F27-050 S/Nos 20103 to 20108 and 20110 to 20129. Requirement: Action in accordance with Fokker SB F50-57-003. Note: RLD AD 88-95 refers. Compliance: Prior to 31 March 1989. Background: Freezing of the cable system has occurred at high altitude, rain, high humidity and low OAT were factors. Installation of this blanking plate will prevent water ingress to this area.