Accident Details
A commercial helicopter pilot was transporting two technicians to a remote site in mountainous terrain. After a 30-minute flight to a staging area, the pilot loaded the passengers and gear and proceeded to a planned landing zone (LZ) at about 2,550 feet MSL in a narrow box-valley. Evaluating the LZ during an out-of-ground-effect (OGE) hover, the pilot determined it was unsuitable. A second LZ was evaluated similarly and also found unsuitable.
Pilot Report
While hovering OGE above a third potential LZ, the helicopter began to descend. The pilot added collective pitch to stop the descent, but the low rotor annunciator horn then sounded and the descent continued. To avoid landing on uneven terrain, the pilot turned the helicopter to the right and downslope while attempting to override the engine governor for additional power. The skids subsequently struck uneven, downsloping terrain. During touchdown, the helicopter nosed down, pivoted left, and rolled onto its left side.
Damage and Findings
The helicopter sustained substantial damage to the fuselage, tail boom, and main rotor drive system. The pilot reported no preaccident mechanical anomalies that would have precluded normal operation. The downsloping wind conditions were described as light and variable.