COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Fokker F28 Series Aeroplanes AD/F28/61 Wings - Rear Spar Web Plate 7/89 Applicability: All F28 aircraft with serial numbers 11003 to 11241 inclusive, 11991 and 11992. Requirement: Action in accordance with Fokker F28 Service Bulletin F28/57-84. Note: RLD AD 89-46 refers. Compliance: Prior to exceeding 35000 flight cycles. Aircraft which have exceeded 35000 but not 45000 flight cycles as at 7 April 1989: Prior to 30 September 1989. Aircraft which have exceeded 45000 but not 55000 flight cycles as at 7 April 1989: Prior to 30 June 1989. Aircraft which have exceeded 55000 flight cycles as at 7 April 1989: Prior to 15 May 1989. Background: Fatigue tests have shown that cracks may develop in the rear spar web plate between STA. 4790 and STA. 5280.