Amateur-built VANS RV6A N646RV accident near Aztec, Arizona

Probable cause

The total loss of engine power for reasons that could not be determined based on available evidence. Contributing to the accident was the pilot’s decision to turn away from a suitable emergency landing surface, his failure to maintain adequate airspeed as the airplane neared the ground, and his exceedance of the airplane’s critical angle of attack, which resulted in an aerodynamic stall.

NTSB analysis

The pilot and passenger were conducting a cross-country flight. Flight track data showed their flight close to and paralleling an interstate highway one to two miles away when the airplane started a controlled descent. During the descent the airplane made a turn away from the highway, made another turn to parallel the highway, and then made a turn angling toward the highway. The flight continued to descend until it impacted terrain about one mile from the highway. The airplane impacted flat desert terrain in a nose-low attitude and a post-impact fire ensued, which consumed most of the airplane wreckage. There were no reported radio calls from the pilot or witnesses to the accident. Investigators could not determine why the pilot initially turned away from the highway, which could have provided a suitable emergency landing surface.

Examination of the engine and propeller found the propeller had broken aft and there were starter ring impact marks of an aft, non-rotational nature. Impact and fire damage prevented any examination of the fuel, air intake, electrical, and ignition systems. There were no signatures or conditions observed during the examination that would indicate there was any pre-accident catastrophic mechanical malfunction. Those findings and the controlled descent made by the airplane from cruise altitude are consistent with a loss of engine power before impact. The nose-down impact attitude is consistent with the airplane entering an aerodynamic stall at low altitude.

The accident is consistent with a total loss of engine power for reasons that could not be determined based on available evidence. Contributing to the accident was the pilot’s decision to turn away from a suitable emergency landing surface, his failure to maintain adequate airspeed as the airplane neared the ground, and his exceedance of the airplane’s critical angle of attack, which resulted in an aerodynamic stall.

Text from the NTSB. Open the NTSB docket for WPR22FA348 for the full record.