CEN16LA084 · Schweizer 269C UNDESIGNAT

The noninstrument-rated private pilot reported that he checked the local weather before he departed in his single-engine helicopter. He said that the weather was good (6 miles visibility and clear skies). Upon the night departure, there was a slight haze about 100 ft above ground level (agl), and he climbed the helicopter to his planned en route altitude of 2,000 ft agl. The first 15 minutes of the flight were uneventful. However, as the pilot approached a river basin area, he started to lose visual reference to the ground, but he thought it was just a small area of fog and that he could fly out of it. He tried to descend but could not see the ground through the fog/low clouds and initiated a climb. The helicopter's altitude ranged from about 1,200 to 2,000 ft agl. The pilot decided to turn around, and while making a slow right turn, the helicopter struck a tree. The pilot tried to initiate a climb, but the helicopter struck another tree. The pilot lowered the collective, and the helicopter descended through the trees to the ground.

The nearest automated weather facility was located about 11 miles southwest of the accident site at an elevation about 200 to 250 ft lower than the accident site. The METAR observation about the time of the accident reported reduced visibility (5 statute miles with mist), a 1° dew point depression, and a cloud ceiling of 1,000 ft agl (which would have been about 750 ft above the accident site elevation). Given the reported weather information and the pilot's statements about the weather conditions, it is likely that the airplane entered instrument meteorological conditions near the accident area at night, which led to the pilot's loss of visual reference to the ground and the subsequent impact with trees and terrain.

Verbatim NTSB analysis and probable cause from the NTSB dataset