NTSB Factual Report

The pilot was landing at an off-airport site in flat-light conditions. After touchdown, the left skid sank into the snow, and the helicopter began rolling to the left. The pilot attempted to correct the roll with right cyclic input, but over corrected, and the helicopter entered a dynamic roll to the right, receiving substantial damage to the tail boom, and main rotor drive system. The pilot stated there were no preaccident mechanical anomalies with the helicopter.

NTSB Probable Cause

The pilot's selection of an unsuitable landing site in flat-light conditions, which resulted in an inadvertent dynamic rollover.