Amateur-built RV-6A N22163 accident near Muskogee, Oklahoma

Probable cause

The pilot's improper decision to continue flight under visual flight rules into an area of reduced visibility weather conditions, which resulted in the pilot's spatial disorientation and subsequent loss of aircraft control. Contributing to the accident was the pilot's lack of recent experience flying in instrument conditions.

NTSB analysis

The instrument-rated pilot was flying under visual flight rules on a cross-country flight and encountered instrument meteorological conditions. A review of the pilot's logbook showed that he had not flown in actual instrument conditions for over five years. The pilot last logged simulated instrument time during his flight review in February, 2007, and prior to then had not logged simulated instrument time since September, 2004. According to the pilot's wife, she thought that the airplane was equipped for instrument flight, but this could not be verified. Radar data showed the airplane changing altitude and making large heading changes during the last ten minutes of flight. The last four radar returns showed the airplane descending in a right turn from 8,500 feet msl to zero altitude in 23 seconds. Witnesses heard the airplane engine running and saw the airplane exit the clouds in a steep nose-down attitude and impact the terrain. Examination of the airplane disclosed no preimpact anomalies. The airplane's turning ground track and the challenging visibility conditions were conducive to the onset of pilot spatial disorientation. The airplane's rapid, near-vertical descent is consistent with the pilot's loss of control of the airplane because of spatial disorientation.

Text from the NTSB. Open the NTSB docket for DEN08LA139 for the full record.