COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Eurocopter BO 105 Series Helicopters AD/BO 105/15 Transmission Flange Shimming 8/92 DM Applicability: All model BO 105 helicopters S/No S 1 up to and including S 876. Requirement: Unless previously carried out action in accordance with MBB (Eurocopter) Alert Service Bulletin No ASB-BO 105-30-104. Note: German AD 92-273 MBB/Eurocopters dated 29 April 1992 refers. Compliance: As specified in the requirement document. Background: The manufacturer has advised that shims fitted to the input/output shaft, installed in the main transmission, intermediate or tail rotor gearbox, may be incorrectly installed. If this condition exist, the pinion gear teeth will suffer rapid wear which if undetected will result in loss of tail rotor drive.