COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Fokker F28 Series Aeroplanes AD/F28/74 Control Column Aileron Chain - Replacement 9/94 Applicability: All F28 aircraft (except Mk 0100) S/N 11003 through 11241, 11991 and 11992. Requirement: Replace all control column aileron chains P/N KH-2212-AF-(X)21 with new units of the same part number, in accordance with Fokker Service Bulletin F28/27-181. Note: RLD AD 93-004(A) refers. Compliance: Replace all aileron chains before 01 March 1995. This AD is effective from 18 August 1994. Background: Two operators have reported incidents where the aileron chain in one of the control columns has failed, causing that pilot to lose aileron control. In both cases, investigation has shown the reason for the premature failure to be fatigue caused by improper initial adjustment of the flight control cables. As it is impossible after time to determine whether the cables on individual aircraft were installed correctly, a one- time replacement of all aileron chains is required to ensure continued safety of operation.