20010516010929A

(-23)Pilot was in cruise at 600' AGL and heard a bang. The helicopter (experimental homebuilt) started to yaw. Pilot started to auto-rotate and at 40 ft. AGL helicopters started to roll. He flew it to the ground and landed straight up. Engine was running following impact and was secured. Pilot found tail drive belt off the pulley at the secondary drive unit. (.19)on may 16, 2001, at 1110 central daylight time, a rotorway 162F helicopter, N311RM, operated by a student pilot, sustained substantial damage when it impacted into a field 15 miles northwest of minneapolis, Minnesota, during an emergency landing. Prior to the emergency landing attempt, the helicopter experienced a tail rotor malfunction. Visual meteorological conditions prevailed at the time of the accident. The personal flight was being conducted under the provisions of 14 CFR part 91. There was no flight plan on file. The student pilot operating the helicopter reported no injuries. The local flight originated from the pilot's residence at rogers, Minnesota, at 1045. In his written statement, the student pilot said that he was returning to rogers, Minnesota, when he heard a "pop" and then the helicopter yawe d left. The student pilot said that he lost pedal control and entered a turning autorotation. He said that at approximately 35 feet above the ground, he introduced some aft cyclic in an attempt to perform a run on landing. He said that the helicopter "spun violently to [the] right". The student pilot said he added full left [control pedal] and down cyclic. The helicopter dropped to the ground. A federal aviation administration inspector examined the helicopter at the student pilot's residence. The inspector observed that both skids were collapsed, the tail boom was bent upward, the bottom vertical stabilizer was crushed upward, and the tail rotor was bent aft. Control continuity was confirmed. An examination of the helicopter's transmission revealed that the lower shaft bearing in the secondary drive assembly was loose. A field test of the drive assembly also showed the short shaft in the drive assembly was sheared.