Incident Overview
A helicopter pilot was practicing slope landings in preparation for an upcoming check ride. According to the pilot, he was positioning the helicopter close to a hill to start the maneuver. The next thing the pilot recalls, the helicopter had rolled to its left, and was upside down and on top of the hill that he was attempting to land beside.
Subsequent Pilot Report
The day following the accident, the pilot reported that he now suspected that the tail rotor drive shaft became disengaged, and caused the accident.
NTSB Examination
The forward tail rotor shaft assembly, and a portion of the adjoining rear tail rotor drive shaft were examined by the NTSB Materials Laboratory for inspection. The inspection discovered no evidence of an in-flight disengagement of the tail rotor drive shaft assembly prior to impact.