Background
According to the pilot's parents, the pilot/owner arrived late in the afternoon on the day prior to the accident. They stayed awake with their son until approximately 0100 on the morning of the accident. The son, a doctor, maintained a busy schedule. He informed his parents that he needed to fly back to have new fuel cells installed in the airplane and to work at his clinic. The pilot was airborne by 0700.
Accident Sequence
The weather at the destination was characterized by low ceilings and fog that restricted visibility. Air traffic control cleared the pilot to fly the localizer approach to the runway. The pilot called his position at the outer marker on the unicom frequency, after which no further transmissions were heard. Witnesses at the airport heard and saw the bottom of the airplane, reporting that the engines sounded normal as it passed overhead. Radar data indicated that the airplane's altitude fluctuated and its ground speed decreased significantly during the missed approach flight path. The airplane impacted the ground in an approximately 40-degree nose-low, right wing down attitude.
Investigation
A toxicology report detected 0.005 µg/ml Tetrahydrocannabinol (marijuana) in the blood, as well as 0.013 µg/ml and 0.017 µg/ml Tetrahydrocannabinol Carboxylic Acid (a marijuana metabolite) in the blood and kidney fluid, respectively.
Probable Cause
The official probable cause was the pilot's impairment of judgment and performance due to drugs, which led to spatial disorientation and a loss of aircraft control. Weather was a factor.