COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Fokker F100 (F28 Mk 100) Series Aeroplanes AD/F100/20 Cleats at Wing Rib STA.8200 4/99 Applicability: F.28 Mk.0100 aircraft, serial numbers 11244 through 11256, 11258 through 11260, 11263, 11268 through 11283, 11286, 11289, 11291, 11293, 11295, and 11297. Requirement: Inspect the cleats at the LH and RH wing rib STA.8200 in accordance with Fokker Service Bulletin (SB) F100-57-018 dated 23 September 1993. Note: RLD BLA 93-142(A) refers. Compliance: Before accumulating 16,000 flight cycles since new. This Airworthiness Directive becomes effective on 22 April 1999. Background: As a result of an inspection during manufacture of the wings for the F.28 Mk.0100, cracks were discovered in the cleats at the LH and RH wing rib STA.8200. Investigation revealed that this was due to incorrect installation of certain Hi-lok bolts in the bottom wing skin. This AD requires an inspection and replacement of the affected cleats.