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/F50/27 Windshield - Post Link Support Bracket- Forward Pressure Bulkhead Applicability: Serial Numbers 20103 through 20108 and 20110 through 20135. 13/89 Requirement: Action in accordance with Fokker Service Bulletin F50-53-008, dated 26 July 1989. Note: RLD AD BLA 89-83 refers. Compliance: Prior to accumulating 20000 flight cycles. Background: Cracking of the subject bracket was discovered during full-scale fatigue tests. Substitution with an improved bracket is called for by this AD.