What happened
While cruising at 15,000 feet, the aircraft exited controlled flight and entered a rapid, nose-down vertical descent. The subsequent impact with the ground resulted in an explosion and a post-accident fire. Investigation of the wreckage site showed that the majority of the debris was concentrated within a single impact crater, though a portion of the left wing was found approximately half a mile away from the primary site.
Prior to this flight, the pilot had notified maintenance staff in a different state regarding several non-functional flight instruments, specifically the autopilot, the horizontal situation indicator, and the artificial horizon gyros. Although the right-side artificial horizon gyro had been replaced by maintenance personnel, no other repairs were conducted. Under an FAA exemption, the pilot was permitted to operate the aircraft alone, provided all essential equipment, including the autopilot and gyroscopic instruments, remained fully operational. Despite the known equipment failures, the pilot proceeded with the flight into instrument meteorological conditions.
Findings
During the flight, the aircraft encountered an area characterized by severe icing and supercooled large water droplets, which altered the aerodynamic performance of the plane. Simultaneously, the pilot was managing several instructions from air traffic control, including a change in radio frequency, a new assigned altitude, and a minor routing adjustment. These factors likely increased the pilot's workload during a period of rapid structural ice accumulation. The combination of malfunctioning flight instruments and the increased cognitive load during icing conditions likely led to pilot disorientation, resulting in the loss of control.