Beech 35-33 N302Z accident near Roff, Oklahoma

Probable cause

The pilot’s loss of airplane control due to spatial disorientation during low-level nighttime flight.

NTSB analysis

The pilot was conducting a personal flight at night in low-visibility conditions. According to automatic dependent surveillance-broadcast (ADS-B) data, during the initial portion of the flight, the airplane’s altitude was generally between 1,000 and 2,000 ft before the airplane climbed to 3,000 ft. About 4.5 minutes before the accident, the airplane entered a gradual descent to an altitude between about 1,400 and 1,500 ft and continued to fly at that altitude (200 to 300 ft above ground level) for about the next 2 minutes. The airplane then entered a left turn that became increasingly tighter. During this turn, the airplane climbed to about 1,600 ft before descending.

The last ADS-B return showed that the airplane was about 0.2 miles west of the last radar return, about 280 ft above ground level, and along a track of about 190°. Postaccident examination revealed no evidence of a pre-existing mechanical malfunction or failure that would have precluded normal operation of the airplane.

The pilot was not instrument rated. The available evidence for this accident did not indicate whether the pilot received weather information for the route of flight. The pilot likely anticipated visual meteorological conditions given that, shortly before takeoff, he informed his wife that the airplane would be in those conditions along the entire route.

The low-visibility night conditions were conducive to the development of spatial disorientation. Although ADS-B data showed that the airplane was flying close to terrain during the final portion of the flight, the airplane was maneuvering over an area without much cultural lighting (such as the illumination from the reflection of lighting in a metropolitan area). Without such lighting, the pilot would not have had reliable visual references for maintaining attitude control. The spiral flightpath was consistent with the pilot experiencing the known effects of spatial disorientation. Also, the wreckage distribution and extensive airplane fragmentation were consistent with a highenergy impact resulting from the effects of spatial disorientation.

Text from the NTSB. Open the NTSB docket for CEN21FA300 for the full record.