What happened
While operating in visual meteorological conditions above a cloud layer, the pilot was established on the localizer portion of an instrument landing system approach. During the approach, the pilot was positioned outside the final approach fix. An air traffic controller issued a series of vectors that directed the aircraft away from the localizer course. These instructions included a 90-degree turn to the left, a descent, and a subsequent 180-degree right turn intended to bring the aircraft back toward the localizer.
As the aircraft performed the right-hand turn and descent, the pilot entered cloud cover. During this maneuver, the aircraft continued to turn with an increasing bank angle, eventually resulting in a ground impact.
Findings
Investigations into the accident identified several contributing factors. The transition from visual flight to instrument conditions, occurring simultaneously with descending turns, created an environment highly conducive to spatial disorientation. The instructions provided by air traffic control involved rapid and large-magnitude heading changes which, when paired with the descent clearance, likely exacerbated the pilot's loss of orientation.
Additionally, toxicological analysis of the pilot revealed the presence of diphenhydramine. While the specific impact of this medication at the time of the event could not be definitively measured, the drug is known to potentially impair physical and mental functions and may have played a role in the development of the pilot's spatial disorientation.