What happened
A student pilot flew to an assigned practice area and performed undetermined maneuvers before the helicopter crashed into a dirt embankment located adjacent to an open field. There were no witnesses to the event.
The investigation
Examination of the wreckage revealed that a main rotor blade (MRB) had severed the tail rotor assembly before the aircraft reached its final resting position. Investigators located the MRB, the tail rotor blade assembly, the horizontal stabilizer, and the tail stinger in a field up to 147 feet away from the main wreckage. The MRB showed evidence of coning upward at a 30-degree angle over the outboard 5-foot portion of its span.
Despite heavy fire damage to the wreckage, no evidence of preimpact mechanical or structural failure was found. Structural deformation observed on the frame was consistent with the aircraft impacting the embankment while descending with forward airspeed. Additionally, no ground scar was observed in the soft dirt surrounding the main wreckage.
Findings
A review of the student's reconstructed flight training records indicated possible training deficiencies regarding responding to equipment malfunctions and performing takeoffs and landings in crosswinds.