COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Fokker F28 Series Aeroplanes AD/F28/58 Main Frame - Flap Track Beam Support Bracket at Wing Station 5280 Applicability: F28 Serial Numbers 11003 to 11241 inclusive, 11991 and 11992. Requirement: Action in accordance with Fokker SB F28-57-81. Note: RLD AD 88-030 refers. 10/88 Compliance: 1. For aircraft with less than 20 000 flight cycles or 10 000 flight hours total time in service - Before exceeding 20 000 flight cycles or 10 000 flight hours total time in service whichever comes first. 2. For aircraft with more than 20 000 flight cycles or 10 000 flight hours total time in service at 6 October 1988 - within 500 flight cycles. Background: As a result of fuel leakage, a crack was revealed in the rear spar web at W.S. 5280, possibly initiated at an unauthorised spot face in the rear spar web. Also bolt holes have been found not perpendicular to the rear spar causing bolt seating deficiencies.