Flight Plan and Pilot Qualifications
The accident flight was operated by a private pilot with approximately 140 hours of flight experience. The pilot was not instrument rated and did not hold a complex airplane endorsement. A night VFR flight plan was filed for a complex airplane, specifying a cruising altitude of 15,500 feet, an airspeed of 140 knots, an en route time of 4 hours, and 8 hours of fuel onboard. The airplane was non-pressurized and carried no supplemental oxygen.
A representative from the airplane manufacturer calculated that the planned flight would require 5 hours and 25 minutes with no wind, which was 25 minutes longer than the maximum estimated capability of the airplane.
Inflight Events
Radar data showed that the pilot flew above 12,500 feet for 2 hours and 17 minutes, above 14,000 feet for 1 hour and 49 minutes, and at approximately 16,000 feet for an estimated 45 minutes. At approximately 3 hours and 40 minutes into the flight, after covering 352 nautical miles, the pilot declared a "Mayday."
The radar data indicated that the airplane departed 14,800 feet and descended through 9,800 feet at approximately 1,077 feet per minute. The airplane maintained a straight flight track until it descended below radar coverage. The impact ground scar, oriented at approximately 280 degrees, was aligned with this flight track.
Engine fuel burn calculations suggested that 10 to 15 gallons of fuel remained in the airplane at the time of the accident.
Wreckage and Systems Examination
Examination of the wreckage revealed that the left wing remained attached to the fuselage and rested uphill. The cockpit area, forward fuselage, and right wing were broken, charred, and consumed by fire. The extent of thermal damage to the fuselage suggested that fuel assisted in the conflagration.
An examination of the engine and other airplane systems revealed no anomalies.