Flight Path
According to radar data, the pilot of the airplane canceled Instrument Flight Rules (IFR) services while on final approach for landing. Shortly after, as the airplane was about 1 mile from the runway end at an altitude of 1,600 feet mean sea level (msl) and a groundspeed of 98 knots, it initiated a left 360-degree turn. This turn was completed within a radius of approximately 0.2 nautical miles, and upon finishing, the airplane was at 1,000 feet msl, heading back toward the airport. Twenty seconds later, the airplane began another left turn to the east, and the radar data ended with the last target at 900 feet msl.
Witness Accounts
Several witnesses observed the airplane in the prevailing weather conditions, which included light drizzle, fog, and darkness. One witness reported that he could easily identify the airplane's navigational lights. He described seeing the nose of the airplane pitch straight up as it simultaneously rolled left onto its back, then the nose dropped straight down toward the ground. The airplane continued to roll a full 360 degrees before impacting the ground nose-first. The witness characterized the maneuver as "very violent and not controlled."
Post-Accident Examination
A thorough examination of the airplane and its engine revealed no mechanical deficiencies that could have contributed to the event.