Accident Details
According to the investigation, a private certificated pilot was cruising at approximately 1,000 feet above ground level (agl) when he observed snow showers ahead. He decided to descend to about 500 feet agl. During the descent, the pilot reduced the engine throttle without first applying carburetor heat. When he added throttle to level the airplane at 500 feet, the engine began sputtering. He then applied carburetor heat, but the engine did not respond and continued running rough, preventing the airplane from sustaining level flight.
Forced Landing
The pilot selected a snow-covered gravel bar for a forced landing. The airplane touched down in snow that was about 18 inches deep. During the landing roll, the airplane nosed over, sustaining damage to the right wing lift strut and the rudder.
Weather Conditions
The pilot reported weather conditions near the accident site as a 1,200- to 1,500-foot overcast ceiling, temperatures between 35 and 38 degrees Fahrenheit, and light to moderate snow showers. According to published carburetor icing charts, the atmospheric conditions (38 degrees and visible moisture) indicated a probability of serious icing at descent power settings.
Postaccident Inspection
A postaccident inspection of the engine revealed no mechanical anomalies.