Incident Overview
A commercial helicopter pilot was conducting a flight to transport three passengers to several remote sites in northern Alaska for snow sample collection. The snow was being gathered from flat, featureless terrain. The pilot successfully reached five of the six predetermined sites but was unable to access the sixth due to low fog, reduced visibility, and flat light conditions.
Sequence of Events
While attempting to return to base camp, the pilot encountered an area of low fog that reduced his ability to discern a horizon. Visibility diminished to the point where he could not identify any topographic features, prompting him to make a precautionary landing to wait for improved conditions. After approximately three minutes, he decided to resume the flight to base camp.
Shortly after takeoff, flat light conditions and worsening fog again impaired his ability to recognize topographical features on the snow-covered tundra. He initiated another landing and lowered the collective, believing the landing gear skids were in contact with the ground. However, the skids were not on the ground, and the helicopter subsequently descended and rolled to the right upon ground contact.
Damage and Injuries
The helicopter continued rolling to the right, and the main rotor blades struck the ground. Upon impact, the main rotor blades sheared off. One of the blades struck the top left portion of the helicopter's cabin, passed through the left side, and struck the passenger seated in the front left seat.
Mechanical Condition
The pilot reported that there were no preaccident mechanical anomalies with the helicopter.