Incident Summary
After takeoff, the pilot reported an engine problem to the controller but did not elaborate. A witness on the ground observed that the left engine was trailing smoke, though it continued to operate without sounding like it was misfiring. The controller asked if the pilot required assistance, to which the pilot responded "no." The controller then cleared the pilot for a left traffic pattern and provided current weather conditions. No further radio transmissions were received from the pilot.
Radar and Flight Path
Smoothed radar tracking data indicated that the airplane turned toward a left downwind and leveled off at 1,400 feet mean sea level (approximately 1,050 feet above ground level) at 156 knots. Over the next 14 seconds, the airplane descended to 1,100 feet and increased airspeed to 173 knots. Radar contact was subsequently lost.
Witness Observations
Multiple witnesses observed the airplane performing various maneuvers: some saw a right snap roll, others a left wingover, followed by a sharp dive to the ground. The wreckage was fragmented upon impact.
Maintenance and Pilot Background
The aircraft had recently undergone maintenance. During that maintenance, unused oil was found inside the left engine cowling, which the pilot admitted he had spilled earlier. After maintenance, the pilot was seen adding three additional quarts of oil to the left engine. The oil dipsticks were calibrated for each engine: the right engine side read 1 3/4 quarts lower than the left engine side.
The pilot held an airline transport pilot certificate with 3,210 hours of flight time reported. He had recently been cleared to operate the aircraft under 14 CFR Part 91. This flight to the maintenance facility was the pilot's first solo flight in that specific airplane.
Investigation Findings
Examination of the wreckage revealed no evidence of mechanical defect, extreme out-of-trim condition, engine failure, detonation, or pre-impact failure. An autopsy of the pilot disclosed the presence of prostate adenocarcinoma; however, according to his physician, the pilot was unaware of the condition.
Probable Cause
The official probable cause is stated as: The pilot's loss of control for undetermined reasons, which resulted in a high speed dive to the ground.