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/F50/1 Central Windshield Post Connection to Pressure Bulkhead Applicability: All model F27 Mk 050 aircraft with serial numbers 20104 to 20107 inclusive. Requirement: Modify in accordance with Fokker Service Bulletin F 50-53-001. Note: RLD BLA No 88-18 refers. Compliance: Before exceeding 10,000 flights. 7/88 Background: The lug at the bottom of the central windshield post has broken on the manufacturer's fatigue test. A modification has been designed to improve the fatigue resistance of this critical structural joint.