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 105/5 Tandem Hydraulic Units - Piston Rods 8/86 Applicability: All model BO 105 helicopters with less than 1200 hours total time in service fitted with Teledyne Hydra-Power tandem hydraulic units P/N 105-45021 with S/Nos: 1012, 1014 to 1019, 1021, 1023, 1027 to 1030, 1032, 1034, 1035, 1037, 1038, 1040, 1041, 1043 to 1046, 1049, 1056, 1057, 1062, 1064 to 1066, 1069, 1071, 1075, 1091, 1093, 1101, 1104, 1109, 1113, 1119, 1121, 1123, 1126, 1127, 1136, 1160 and 1161. Requirement: Action in accordance with MBB SB 40-19, or SB 40-21. Compliance: Inspect at 600 hours total time in service and again at 1200 hours total time in service. Background: Cracks have been found on piston rods of Teledyne Hydra-Power actuators. LBA AD 75-172/2 MBB also refers.