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/F50/50 Windshield Wiper System 1/92 Applicability: Model F27 MK 050 series with serial numbers 20213 through 20227. Requirement: Action in accordance with the technical requirements of RLD AD 91-130. Note: Fokker SB F50-30-016 refers. Compliance: As specified in the requirement document with a revised effective date of 12 January 1991 for Australian Registered Aircraft. Background: This Directive requires the windshield Piper system to be modified as it does not meet the specifications of the vendor.