What happened
Following takeoff, the pilot was granted progressive altitude increases, eventually reaching flight level 200. During the cruise phase, the pilot reported encountering moderate turbulence. At approximately 10:25 CDT, the flight crew received clearance to climb to flight level 220. Shortly after this transition, the pilot noted the aircraft was positioned within a cloud layer between 20,000 and 21,000 feet.
Shortly after entering the clouds, the aircraft began experiencing significant altitude deviations. The plane climbed above its assigned altitude of 22,000 feet before descending to approximately 20,500 feet, followed by a pitch-up to 23,000 feet. This was followed by a rapid, steep descent. As the aircraft emerged from the cloud layer near 2,000 feet, it suffered an in-flight breakup. The wreckage was distributed across a large area, with the left wing located roughly 0.2 miles from the main fuselage and components of the rudder and stabilizers found approximately 100 yards away. Both occupants were killed in the accident.
Findings
Investigation of the structural fractures on primary components indicated damage consistent with overstress separation. No evidence of pre-existing cracks was identified in the wreckage. Environmental conditions in the area included forecasts for IFR conditions, thunderstorms, and icing near convective activity. Additionally, the pitot heat switch was discovered in the 'off' position.