Accident Overview
A helicopter pilot was transporting two search and rescue volunteers and their equipment to the site of an avalanche when the accident occurred. The helicopter was equipped with floats.
Landing Zone Details
A helicopter landing zone (heli spot) had been established the evening before the accident, located near the toe of the avalanche at an elevation of 5,300 feet msl. The heli spot was situated near the bottom of a small valley. The zone had been used previously by a military helicopter and was marked with small flags. The surface of the snow at the heli spot had been dusted with red powder. The accident pilot had not landed at this heli spot before.
Approach and Incident
The pilot began the landing approach toward the west. Weather conditions were clear, but the pilot reported that lighting conditions in the valley provided little contrast (flat light). As the pilot added power near the termination of the landing approach, the low rotor warning horn sounded. The main rotor gauge indicated 92 to 94 percent rotor speed. The pilot reduced collective pitch, confirmed the throttle was fully open, and initiated a go-around toward the west, an area of lower terrain.
Collision and Rollover
Despite the go-around, the helicopter continued to descend. The right front portion of the landing gear float assembly contacted the snow. Around the same time, the main rotor struck the slope of a small, snow-covered hill to the right of the helicopter. The helicopter then rolled onto its right side.
Post-Accident Observations
After the accident, the pilot noted that the wind was blowing about 8 knots from the east.