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/F100/28 MLG Apex Joint and Shimmy Damper Attachment 4/99 Applicability: F.28 Mk.0070 and Mk.0100 aircraft, all serial numbers, if equipped with Menasco Aerospace Main Landing Gear (MLG) Units (LH) Part Number (P/N) 41050-5, 41050-7 or P/N 41060-1; and (RH) P/N 41050-6, 41050-8 or P/N 41060-2. Requirement: Inspect the Main Landing Gear Apex Joint and Shimmy Damper in accordance with the Accomplishment Instructions of Fokker 70/100 Service Bulletin (SB) F100-32- 113 dated 28 May 1998. Note: RLD BLA 1998-058(A) refers. Compliance: Unless already accomplished before 3 June 1999. After 22 April 1999, no affected spare MLG units may be installed as a replacement part unless it has been inspected in accordance with the Requirement of this directive. This Airworthiness Directive becomes effective on 22 April 1999. Background: An operator reported a landing incident with a F.28 Mk.0070 where heavy vibration was felt during roll-out, coming from the main landing gear. The initial inspection, after the aircraft had been stopped on the runway, revealed the torque links of the RH MLG to be disconnected at the apex joint. Subsequent inspections of other aircraft revealed that in some cases, loss of torque was also found on the torque link centre joint apex bolt and shimmy damper attachment bolts. The compliance date for inspections of affected parts installed on aircraft has already passed.