Accident Overview
A commercial pilot departed on a cross-country personal flight without filing a flight plan. No evidence was found that the pilot received a preflight weather briefing. Visual meteorological conditions existed at the departure airport, but during the climb, conditions transitioned to instrument meteorological conditions (IMC) with precipitation, microburst, and rain showers over the accident area.
Flight and Weather
During the takeoff clearance, the air traffic controller cautioned the pilot about deteriorating weather about 4 miles east of the airport. Radar data showed that about 5 1/2 minutes after takeoff, the airplane climbed to about 7,800 ft above ground level before starting a rapid descending right turn. It impacted the ground about 9.6 miles east of the departure airport.
Loss of Control and Breakup
Recorded data from the airplane's Appareo Stratus 2S revealed that during the last 15 seconds of the flight, the airplane's attitude changed erratically, with pitch fluctuating between 45° nose-down and 75° nose-up, and bank between 170° left and 150° right while descending from 5,500 to 500 ft, indicating a loss of control shortly after entering clouds. Witnesses near the accident site reported seeing the airplane exit clouds at a high descent rate, followed by parts breaking off. One witness observed the airplane exit the overcast layer with a nose-down pitch of about 60°, remaining in that attitude for 4-5 seconds before a high-speed dive recovery, at the bottom of which the left horizontal stabilizer separated, followed by the remaining empennage, then the left wing sheared off near the left engine, and the wing ignited. An outdoor home security camera captured the airplane exiting clouds trailing black smoke and then igniting.
Examination of the debris field and fracture surfaces revealed that both wings and the one-piece horizontal stabilizer and elevators separated in flight due to overstress from excessive air loads. Although the airplane was equipped with an autopilot, erratic heading and altitude variations during the last 15 seconds indicated the pilot was likely hand-flying, and likely induced the excessive loads while attempting to regain control. Conditions conducive to spatial disorientation existed, including restricted visibility and IMC entry. Flight track data was consistent with spatial disorientation and loss of control.
Pilot Toxicology
Toxicology testing detected delta-9-tetrahydrocannabinol (THC) in heart blood, indicating prior marijuana use. Investigators noted no direct relationship between postmortem levels and antemortem effects; postmortem redistribution suggested the antemortem level was likely lower and from use days earlier, making it unlikely that marijuana contributed to poor decision-making. Testing also detected 67 ng/mL of diphenhydramine, a sedating antihistamine. Postmortem redistribution may increase heart blood levels by about three times, so the antemortem level was likely at or below the lowest level expected to cause significant effects, and it is unlikely that diphenhydramine contributed to the accident.