Accident Overview
The airplane struck terrain while on the downwind leg as it approached a point abeam the runway threshold. The aircraft had maintained a gradual descent while flying south of the airport, then completed a left turn to the north on the downwind leg. It continued descending until impact with the ground.
Pilot's Vision and Cockpit Lighting
Auxiliary lighting had recently been installed in the glareshield, but it did not provide adequate illumination. The pilot compensated by clipping two flashlights onto the glareshield and using two additional handheld flashlights to light the instrument panel. The flight continued under these conditions.
The pilot had undergone significant surgery on at least one eye in the past, including a corneal transplant. Such surgeries can lead to complications that substantially impair vision. The overall lighting level in the cockpit, augmented by the flashlights, would have essentially prevented any dark-adaptation of the pilot's vision and interfered with his ability to see clearly outside the aircraft.
Toxicology and Impairment
Toxicological analysis of specimens from the pilot was positive for benzoylecgonine and ecgonine methyl ester (inactive metabolites of cocaine), cocaine, temazepam, oxazepam, and acetaminophen. The pilot was likely impaired by the effects of cocaine withdrawal, and possibly by the use of a prescription sleeping aid. The presence of a medication used for pain or fever control implied that such symptoms were significant. Distraction, sensory disturbance, or impaired judgment resulting from illness could conceivably have played a role. It is also possible, though less likely, that the pilot experienced an acute event such as fainting or seizure due to drug use, leading to incapacitation.
Impact and Occupant Dynamics
Upon impact, the pilot and passenger were thrown forward and to the right. The lack of shoulder restraints concentrated deceleration forces on the lap belt, causing the floor attachment point to separate from the floor. The damage, deformation, and fractures observed were typical of a single overload event, indicating substantial forward rotation of the attachment point during separation. This rotation, combined with centrifugal force, allowed the pilot to strike the instrument console to his right.