What happened
Radar data tracked the aircraft performing a figure-eight maneuver at approximately 3,000 feet AGL. During this maneuver, the aircraft maintained an estimated airspeed of 140 knots and a bank angle of approximately 40 degrees. After completing the maneuver, the aircraft transitioned into level flight before entering a rapid descent.
A witness observing the aircraft in visual conditions noted that the plane appeared to be flying at a high altitude and at a high speed. The witness observed the aircraft execute a wide, shallow left turn followed by a turn in the opposite direction. Following these maneuvers, the nose of the aircraft began to lower gradually, eventually resulting in the airplane descending straight down into a spin. The witness lost sight of the aircraft behind hilly terrain prior to impact.
The investigation
A post-accident examination of the wreckage revealed that the aircraft struck the terrain in a slight nose-down attitude within a gully, with an approximate bank angle of 30 degrees. Following the collision, the aircraft slid downhill to the right. The aircraft came to rest with the fuselage in an upright position, though the empennage was inverted and twisted to the right.
Investigators found no evidence of any mechanical failure or malfunction contributing to the accident.