COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Fokker F27 Series Aeroplanes AD/F27/108 Rudder Trim Tab Control Bracket Attachment - Inspection 6/86 Applicability: All Models. Requirement: Fokker Service Bulletin F27/55-58. NOTE: R.L.D. AD 85-31 refers. Compliance: Prior to 15 July 1985. Background: Investigation into a flutter occurrence revealed that substitute rivets had been installed in the rib skin attachment of the rudder trim tab actuating bracket. The clamping qualities of the installed rivets may substantially reduce stiffness of the tab control attachment.