Flight and Incident
According to the pilot, the engine began to run rough and subsequently lost power while the airplane was in cruise flight at an altitude of 6,500 feet MSL. The pilot attempted to land at a nearby airport but landed short in a field approximately one mile southeast of the airport. During the landing roll, the airplane impacted a fence and fence posts, causing leading edge damage to one wing and structural damage to both wing struts.
Post-Accident Examination
An FAA inspector, the aircraft owner, and a representative from the engine manufacturer examined the engine at a local fixed-base operator (FBO). The contents of the fuel system were inspected, and evidence of fuel contamination was found. The fuel in the tanks was yellow/straw in color and lacked the appearance of 100LL fuel; however, no diesel or jet fuel was detected.
Engine Testing
New spark plugs were installed, and the airplane was defueled and serviced with fresh 100LL fuel. The engine was then started and operated normally through its normal operating range.