Incident Overview
A pilot reported that a takeoff proceeded normally until reaching approximately 50 feet above ground level. At that point, the engine lost power immediately after the pilot closed the carburetor heat. The aircraft's landing gear subsequently contacted the top of a security fence located beyond the departure end of the runway. The impact caused the aircraft to bounce into an adjacent plowed field, where it came to rest in a nose-down attitude.
Pilot's Observations
Before exiting the aircraft, the pilot checked the fuel valve and discovered it was not locked in the full forward position. Instead, the valve was found midway between the ON and OFF positions. The pilot stated that, in retrospect, he was not certain that he had placed the fuel valve in the full forward position during the pre-flight inspection. He attributed the engine power loss to this incorrect fuel valve position.
Investigation Findings
The investigation focused on the pilot's account and the condition of the fuel selector. No further details about the aircraft type, registration, date, or location were provided in the source. The pilot's statement about the fuel valve position was the only explicitly stated cause for the engine power loss.