COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Grob G115 Series Aeroplanes AD/GROB 115/3 Steering Damper Bushes 3/91 Applicability: Model Grob G115A with serial numbers 8090 through 8109. Requirement: Action in accordance with the technical requirements of German LBA AD 90-344. Note: Grob SB TM 1078-17 refers. Compliance: Unless already accomplished; before the next flight after 21 March 1991. Background: During the manufacture of the G 115A, some oversize bushes were installed in the steering damper 115-4220. Under certain circumstances this can cause the rudder to jam.