Overview
The accident occurred during an instrument flight rules (IFR) flight. The pilot made a routine position report 12 minutes before the accident. Subsequently, witnesses observed an 'orange ball' before the crash.
Evidence of Inflight Fire
Examination of the crash site revealed evidence of an inflight fire outboard of the right engine. Investigators found a loose B-nut on a fuel line in that area. The most extensive fire damage was located in the right cockpit floorboard area. Additionally, the cockpit portable fire extinguisher had been partially expended, indicating an attempt to fight the fire.
Structural Failures
The inflight fire and associated conditions led to several structural events. The pilot's emergency window was jettisoned in flight. There was also positive aerodynamic overload separation of the horizontal stabilizer and elevator components.
Pilot's Actions and Toxicology
Toxicological examination of the pilot revealed a 10 percent carbon monoxide level. However, an oxygen system was installed on the aircraft, which may have been used by the pilot during the inflight emergency.