COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Fokker F28 Series Aeroplanes AD/F28/71 Wing to Fuselage Skin Connection 13/92 Applicability: Serial Numbers 11003 to 11161 inclusive, 11991 and 11992. Requirement: Reinforce the connecting angles in accordance with RLD AD 91-055, dated 14 June 1991. Note: Fokker SB F28/53-101 refers. Compliance: Before 30,000 flights, or 1 June 1997, whichever is the later. Note: This reinforcement eliminates the need for further inspection in accordance with the F28 Structural Integrity Program, Part 1, item 53-10-14 (AD F28/45). Background: Fatigue cracks have been reported in earlier F28 connection angles, which form part of the centre wing to fuselage skin connection. Service experience has shown that these cracks can grow to a large size between inspections. The RLD has therefore determined that modifying these angles should be a mandatory requirement.