NTSB Factual Report

On November 16, 2015, about 1040 eastern standard time, a Eurocopter EC120B helicopter, N88HA, experienced a complete loss of tail rotor thrust while on approach for a precautionary landing at the Goshen Municipal Airport (GSH), Goshen, Indiana. The helicopter sustained minor damage. The pilot and flight instructor were not injured. The helicopter was registered to Hanscopter LLC and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 as an instructional flight. Day visual meteorological conditions prevailed for the flight, which was not operated on a flight plan. The local flight originated from the Elkhart Municipal Airport (EKM) about 1000.

The flight instructor reported that they were returning from the local instructional flight when they heard a faint noise that correlated with engine speed. The flight crew elected to divert to GSH for a precautionary landing, which was about 3 miles from their current position. As they approached the airport, the noise level increased. At this time, the flight instructor took the controls. About 15 feet above ground level and 25 knots, the helicopter began an uncommanded left yaw. A corresponding right pedal input was not effective in stopping the left yaw. The flight instructor immediately reduced engine power and initiated a hovering autorotation.

An initial postincident examination revealed excessive wear between the air conditioning system compressor drive pulley and the main gear box tail rotor drive pinion. Further examination of the affected components is pending.