Flight Operations
The pilot had completed two long-line cargo movements in light dry snow. After the second load, the pilot observed that the snow had become wet and heavy and informed the ground crew he was leaving the area. As he turned to depart, a ground crew member radioed, noting that the pilot would pass near one of the loads, and suggested picking it up. The pilot maneuvered toward the load and entered a hover to swing the long-line hook forward.
Engine Power Loss
Just as the pilot entered the hover, the engine lost power. The pilot stated that when he changed the angle of attack to position the hook, he believes a layer of wet snow and ice crystals lifted off the canopy and entered the engine particle separator, leading to the power loss.
Emergency Autorotation
The pilot delayed the initiation of an emergency autorotation to allow the ground crew person to find cover. As a result of this intentional delay, rotor system energy decayed, and the pilot was unable to control the descent. The helicopter settled onto the terrain at an excessive rate of descent.
Postaccident Inspection
A postaccident inspection did not reveal evidence of any system malfunction or anomaly.