Accident Details
The accident occurred at Jackson-Hole Airport (JAX) in very dark night conditions with a 2,000-foot overcast ceiling and no visible horizon. The pilot, sole occupant of the aircraft, was killed when the aircraft impacted the ground in a vertical dive after a series of extreme maneuvers.
Pilot Operations
The pilot had arrived at JAX approximately 30 minutes prior to the accident with two passengers. After dropping off the passengers, the pilot went to the operations area for a short break before returning to the aircraft alone for a return flight to California. The pilot had departed Redding, California, at 1357 hours and had been on continuous flight duty from that time until the accident. A witness reported that the pilot appeared tired and hungry.
Flight and Accident Sequence
The aircraft was observed making a normal night takeoff. However, as it turned from crosswind to downwind, witnesses reported that the pilot appeared to have difficulty controlling the aircraft. The aircraft then performed several extreme up-and-down maneuvers before proceeding east. Subsequently, it was again seen climbing and descending rapidly and ultimately impacted the ground in a vertical dive.
Probable Cause
The official probable cause includes an altitude deviation and uncontrolled descent during climb to cruise. Contributing factors were dark night conditions, the pilot's poor planning and decision-making, fatigue from the flight schedule, improper use of flight controls, and spatial disorientation.