Background
Before departure, the airplane was fueled to capacity and placed in a heated hangar about one hour prior to flight. The pilot, who held an instrument rating, obtained a weather briefing and filed an IFR flight plan. An IFR clearance was subsequently issued. The airport control tower personnel were unable to observe the takeoff due to low ceiling, reduced visibility, and ice fog.
Accident Sequence
Radar data from the National Track Analysis Program and onboard GPS information indicated that the airplane began drifting to the left of the runway centerline almost immediately after takeoff. The aircraft then executed a climbing left turn, attaining a maximum altitude of 7,072 feet and completing 217 degrees of turn before transitioning into a descending left turn. The airplane ultimately impacted terrain on airport property.
Post-Accident Findings
Autopsy and toxicology protocols were unremarkable. Examination revealed no evidence of preimpact failure or malfunction of the airframe, powerplant, propeller, or flight controls. The autopilot and servos, pitot-static system, and flight instruments were all tested and functioned satisfactorily. The pilot's shoulder harness was found attached to the seatbelt, but the male end of the seatbelt buckle was broken.
Probable Cause
The probable cause of the accident was the pilot's spatial disorientation, which led to his failure to maintain aircraft control. A contributing factor was the pilot's decision to intentionally fly into known adverse weather that consisted of low ceilings, obscuration, and ice fog.