Accident Sequence
The airplane collided with terrain while turning from base to final for landing. The pilot had contacted the air traffic control tower approximately 20 miles from the airport. The controller cleared the pilot into the traffic pattern and shortly thereafter cleared the airplane to land. The turn to base was early, and the airplane remained high during the base leg and the turn to final. The controller informed the pilot that the landing gear did not appear to be down. Subsequently, the airplane rolled to the right.
Witness Observation
A pilot witness observed the right wing drop 70 to 80 degrees and the airplane enter a sharp right turn through 180 degrees of rotation. The nose started dropping and after 360 degrees of turn, the nose was down about 70 degrees to a vertical nose-down attitude.
Post-Accident Examination
Investigators discovered no preimpact engine or control malfunctions with the airplane.
Pilot Medical History and Toxicology
Review of the pilot's personal medical records indicated that he had routinely used a prescription sleep aid (triazolam) and two prescription medications (codeine and butalbital) for the treatment of severe headaches. The pilot noted none of these medications on his applications for a medical certificate. A postmortem toxicological examination detected the presence of codeine and butalbital, consistent with recent use. Barbiturates (the class of medications that include butalbital) have been shown in many studies to impair judgment and performance, with impairment that does not always correlate with subjective effects. They have an effect on the inner ear and may increase susceptibility to spatial disorientation. Studies have shown residual adverse effects of triazolam on piloting-related skills in the morning following its use. Codeine, a narcotic painkiller, has been shown to have mild impairing effects on performance at typical doses.