Flight and Incident
A commercial pilot was conducting a cross-country flight when the aircraft's engine began to run rough at an altitude of 3,500 feet Mean Sea Level (MSL) while operating at a low cruise power setting. The pilot reported the engine malfunction and initiated troubleshooting procedures.
Pilot Actions
In response to the rough-running engine, the pilot checked the mixture control, fuel selector, magneto switch, and subsequently applied carburetor heat. Despite these efforts, the engine continued to operate roughly and eventually lost power completely at approximately 600 feet above ground level (AGL).
Forced Landing
With the engine inoperative, the pilot executed a forced landing in an open field. During the landing roll, the aircraft impacted a barbed wire fence and collided with a small tree before coming to rest.
Investigation
The subsequent investigation into the loss of engine power was unable to determine a definitive cause. The available evidence did not establish why the engine failed, and no specific mechanical or operational factor could be identified.