What happened
During his descent toward his destination, the pilot experienced what he described as a "rough engine." In response to this engine performance issue, he attempted a precautionary landing at a nearby farm airport. While on approach to the landing area, the pilot misjudged the location of a power line, striking the wire before making a hard landing in a farm field. The pilot was not injured.
The investigation
An examination of the wreckage by an FAA inspector revealed that the aircraft's fuel tanks were nearly full of either automotive or mixed automotive/aviation fuel. While the pilot believed the engine roughness was caused by carburetor icing, weather observations from the nearest station at the time of the accident showed no temperature or dewpoint conditions that would indicate a risk of carburetor ice. Furthermore, the pilot reported that he was unaware of the exact amount of fuel on board at the time of his last takeoff.
Findings
The investigation identified several regulatory and maintenance discrepancies. The pilot had not completed a required biennial flight review in approximately 11 years and did not hold a current medical certificate. Additionally, the aircraft had not undergone any inspections within the previous four years.