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/F50/41 Outboard Flap Drive 3/91 Applicability: Model F27 MK 50 with serial numbers 20103 and 20107. Requirement: Action in accordance with RLD AD 90-148. Note: Fokker SB F50-27-026 refers. Compliance: As specified in the Requirement Document. Background: Several outboard flap drive assemblies have been identified as not being in compliance with current regulations.