Accident Sequence
The accident occurred during a personal cross-country flight conducted by an instrument-rated private pilot. According to air traffic control (ATC) transcripts and radar data, the pilot was executing the RNAV GPS Y instrument approach to the runway. The controller canceled the approach clearance and issued a heading change to provide spacing from a preceding aircraft; the pilot acknowledged.
Radar data showed that the airplane began a left climbing turn from 5,600 to 5,800 ft, continued through the assigned heading of 270°, and then descended rapidly. The airplane disappeared from radar display, with the final recorded return at 5,100 ft. The airplane then impacted a television tower guy wire, several power lines, and terrain, coming to rest about 800 ft from the tower in an open field.
A witness in a parking lot adjacent to the tower reported hearing the airplane overhead, seeing a bright flash filling his field of view, and then observing the tower collapse. Surveillance videos from locations 1.5 miles north-northeast and 0.3 mile north-northwest of the accident site showed the airplane in a left descending turn near the tower, followed by multiple bright flashes consistent with impacting the guy wire and power lines.
Investigation Findings
Postaccident examination of the airplane and engine revealed no anomalies that would have precluded normal operation. Rotational signatures on the first stage compressor blades and light rotational signatures in the compressor and power turbines, along with debris in the engine's gas path, indicated engine rotation at impact.
Weather conditions at the destination airport were conducive to ice accumulation around the time the pilot initiated the left turn. The investigation concluded that the airplane likely accumulated at least light structural icing during the descent, which could have affected controllability. Additionally, the airplane likely encountered wind gusts up to 31 knots as it turned, also potentially affecting controllability.
The night, instrument meteorological conditions at the time were conducive to spatial disorientation. The airplane's rapid, descending left turn to impact is consistent with a loss of control due to spatial disorientation. The investigation determined that while initiating the climbing left turn, the pilot became spatially disoriented, resulting in loss of airplane control and failure to see and avoid the tower guy wire. The light ice accumulation and gusting wind negatively affected controllability.
Probable Cause
The probable cause of the accident was the pilot's loss of airplane control due to spatial disorientation and light ice accumulation while operating in night, instrument meteorological conditions with gusting wind.