Accident Sequence
After takeoff, the pilot flew about 30 miles and climbed to approximately 2,200 feet mean sea level. About 8 minutes after takeoff, the airplane entered a descending left turn that continued until impact. A witness observed the twin-engine airplane at low altitude in a descent. After it descended below the tree line, a fireball emerged followed by thin smoke that dissipated quickly. Another witness saw the airplane at low altitude in a slow, descending turn with steady wings that never dipped, and shortly after it descended out of sight, an explosion occurred.
Both engines were on fire when a witness arrived, and a fuel leak from the right engine toward the cockpit area was noted. The witness used a fire extinguisher to keep fire off the fuselage until first responders arrived. The airplane impacted a utility pole and terrain. Burned vegetation was present over portions of the accident site. The left wing separated outboard of the engine and was located near the utility pole.
Postaccident Examination
A postaccident examination revealed that the left main fuel tank was partially consumed by the postimpact fire, so the amount of fuel in the tank could not be determined. The left engine nacelle was discolored consistent with postimpact fire. The left nacelle fuel tank appeared intact with no visible fuel, but the amount of fuel at impact could not be determined. The right main fuel tank appeared intact, and about 1 gallon of fuel was drained during recovery. While the postimpact fire was consistent with fuel present onboard, the lack of an extensive and sustained ground fire suggested a limited amount of fuel was present.
The left and right engine cockpit fuel selectors were both positioned to the “RIGHT MAIN” fuel tank. The left fuel selector valve, located in the engine nacelle, was in the “OFF” position. The right fuel selector was in the “RIGHT” fuel tank position.
A teardown examination of the left engine revealed no anomalies consistent with a preimpact failure. The right engine teardown revealed damage consistent with oil starvation throughout the engine. The left propeller assembly blades were at or near the feather pitch stop during impact, while the right propeller blades were on or near the low pitch stop.
The fuel flow indicator displayed 8.3 gallons total fuel remaining when powered on a test bench, but the device does not directly provide fuel quantity information; indications depend on proper configuration during refueling. According to the airplane flight manual, total unusable fuel with one engine nacelle fuel tank installed was 7.8 gallons.
Engine Performance Data
Engine monitor data revealed a reduction in right engine power to near idle. About 1 minute later, the airplane entered a descending left turn that continued until impact. About 3 minutes after the reduction in right engine power, the left engine completely lost power. Immediately afterward, right engine power increased to near full takeoff power, but about 30 seconds later the right engine completely lost power. The airplane impacted the pole and terrain a few seconds later.
The pilot likely detected an impending failure of the right engine and intentionally reduced power. Shortly afterward, the left engine lost power due to fuel starvation. The pilot likely set the left engine to crossfeed from the right main fuel tank to restore power but was unsuccessful. He then decided to feather the left propeller and attempted to use any available power from the right engine, but the right engine immediately lost power as well. Whether the right engine lost power due to fuel starvation or oil starvation could not be determined.
Pilot Medical and Toxicology
The pilot was obese and had hypertension, high cholesterol, and an enlarged heart with left ventricular thickening. The autopsy did not show any acute or remote myocardial infarction, and the flight path suggests intentional actions until the crash. Thus, the pilot’s cardiovascular disease was not a factor. Toxicology testing detected cyclobenzaprine and its active metabolite at low therapeutic levels, and zolpidem at subtherapeutic levels. The operational findings did not suggest performance issues related to fatigue, so it is unlikely that these substances were factors.