Amateur-built Sonex Light Sport N620AK accident near Centerville, Utah

Probable cause

The pilot flying’s exceedance of the airplane’s critical angle of attack during an attempted forced landing, which resulted in an aerodynamic stall and impact with terrain. The reason for the attempted forced landing could not be determined.

NTSB analysis

A resident who lived near the accident site observed the airplane flying at a “normal altitude” from west to east. Shortly thereafter, he heard a “backfiring” sound and watched the airplane until it flew out of sight; he did not observe the accident. Dash cam video of the accident sequence captured the airplane coming into view traveling from north to south at a low altitude. The airplane then entered a descending right 180° turn, in what appeared to be a normal bank attitude. As the airplane proceeded through 90° of the right turn, the bank angle increased significantly. Shortly thereafter, the airplane impacted terrain in a nose- and right-wing-low attitude, consistent with an aerodynamic stall. The airplane burst into flames, which resulted in the forward cabin/cockpit area being consumed by fire.

The accident location was about 300 ft east of what appeared to be the approach end of an abandoned/reclaimed runway that was oriented north-south, and the airplane’s flightpath prior to the accident was consistent with a downwind approach and a right turn to base and final approach for a forced landing on a suitable surface.

The airplane was occupied by the owner-pilot and a pilot-rated passenger. The pilot/owner was not authorized to act as pilot-in-command; however, the investigation could not determine which pilot was controlling the airplane at the time of the accident.

A postaccident examination of the airframe and engine did not reveal any mechanical anomalies with the airplane that would have precluded normal operation. The airplane was operating in weather conditions conducive to the formation of carburetor icing at cruise and glide power settings; however, the investigation could not determine if a partial or total loss of engine power had occurred prior to the airplane impacting terrain. The accident is consistent with the pilot exceeding the airplane’s critical angle of attack during an attempted forced landing, which resulted in an aerodynamic stall and impact with terrain.

Text from the NTSB. Open the NTSB docket for WPR20LA196 for the full record.