What Happened
During a late-night flight, the pilot turned on the heater. Approximately 40 to 45 miles north of the Leona VOR, the pilot reportedly engaged the autopilot and began working on flight logs. About 50 miles further north, the aircraft flew into a field in a wings-level attitude. The pilot could not recall anything from the time the autopilot was engaged until impact.
Examination Findings
An examination of the aircraft revealed that the auxiliary fuel tanks were empty and no fuel was found in the fuel flow divider or fuel injector lines. Additionally, the propeller blades were bent aft. The pilot suspected carbon monoxide from the heater, but an examination of the heater showed it was well within published parameters and had no significant discrepancies.
Pilot Information
The pilot was also employed as a construction supervisor during the day.