What happened
The pilot was approaching a remote, snow-covered mountain site, flying into the wind. As the helicopter descended to approximately 50 feet, the wind shifted and increased in velocity. This change caused the aircraft to begin a rapid descent. In an effort to arrest this rate of descent, the pilot increased power; however, the low rotor RPM horn soon sounded.
The aircraft touched down just beyond the intended landing site with enough forward speed and force that the pilot could not maintain the position on the landing site. To prevent the aircraft from falling off a nearby 30-foot drop, the pilot applied forward cyclic. Because of the low rotor RPM and the inability to maintain altitude, the pilot chose to land in a large, open snowfield.
During this landing, the helicopter settled into the snow, causing the main rotors to strike the ground. This resulted in the aircraft rolling over. At the time of the accident, the weather was characterized by high overcast with winds reported at 15-20 knots, though the specific wind direction was not indicated.