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/F50/17 Fuel Collector Tank Supply Line 5/89 Applicability: Model F27 Mark 050 with serial numbers 20104 through 20108. Requirement: 1. Inspect the fuel collector tank supply line (fwd line looking in the direction of flight) and the sheepskin - covered edges of the feedthrough holes at STA 3038 of both engine nacelles for evidence of chafing. 2. Action in accordance with Fokker 50 SB No. F50-28-003. Note: RLD AD BLA 89-18 refers. Compliance: 1. Within 65 hours time in service after 31 May 1989, until modified in accordance with Fokker 50 SB No. F50-28-003. 2. Prior to 31 August 1989. Background: The manufacturer has determined that a modification to enlarge the STA 3038 nacelle feedthrough hole and fit ant-chafe material to the fuel supply line, will eliminate interference and possible fuel leakage.