NTSB Factual Report

According to the pilot, approximately 10 minutes after takeoff, the airplane was in cruise flight when the engine "suddenly ran rough, appeared to lose power, then ran rough again." The pilot applied carburetor heat and switched fuel tanks, but this had no significant effect. During the forced landing in tall grass in a barley field, the airplane nosed over. The airplane's vertical fin and rudder were bent, and the propeller was damaged. After the airplane was recovered to an airport, an FAA inspector started the engine and operated it at an idle power setting. The reason for the partial loss of engine power was not determined.

NTSB Probable Cause

The loss of engine power for an undetermined reason. A contributing factor was the lack of suitable terrain for the forced landing.