Primary finding
Probable cause
The pilot's failure to maintain clearance from snow-covered terrain during the landing approach in flat light conditions.
Investigator assessment
Analysis narrative
The pilot stated that while on approach to land at a remote, snow-covered glacial site, with flat light conditions present, he lost “positive” visual reference, but believed he was in a stable hover. Subsequently, the left landing gear skid contacted the snow-covered terrain, and the helicopter entered a dynamic rollover to the left, resulting in substantial damage to the fuselage, tail boom, and powertrain system. The pilot reported that there were no preaccident mechanical malfunctions or anomalies that would have precluded normal operation.