ERA18FA056 · Beech G35

The commercial pilot was conducting a long cross-country flight. There was no record that he received a weather briefing from an official source, and he did not file a flight plan before departing. The pilot completed the first leg of the trip uneventfully and purchased fuel at an intermediate stop. During the second leg, about 30 minutes after takeoff and over a period of about 20 minutes, the airplane climbed from 3,400 ft mean sea level (msl) to 7,100 ft msl. It then made two left, 360° turns, followed by a rapid descent to 1,400 ft msl. During the next approximate hour, the target flew east at alternating altitudes below 2,500 ft msl, before turning south, flying s-turns and descending to 1,400 ft. The target proceeded south at 1,100 ft msl until about 10 minutes before the accident, when it flew near a cold front boundary. After that, the airplane completed numerous course deviations, including three complete left 360° and two right 360 turns; the last recorded radar return was about 0.4 mile east of the accident site at an altitude of 450 ft msl. The recorded weather near the accident site about the time of the accident included 10 miles visibility and an overcast ceiling at 600 ft. Examination of the airframe and engine did not reveal any preimpact mechanical malfunctions that would have precluded normal operation.

Although the pilot held an instrument rating, his most recent simulated instrument experience was about 11 months before the accident and his most recent actual instrument experience was more than 2 years before the accident. The dark night, restricted visibility conditions, and the pilot's extensive maneuvering in the last 10 minutes of flight, coinciding with the frontal boundary, provided conditions conducive to the development of spatial disorientation. The final path of the airplane in a direction opposite the last radar returns and the airplane's steep impact angle are consistent with the known effects of spatial disorientation and a subsequent loss of control.

Verbatim NTSB analysis and probable cause from the NTSB dataset