Accident Sequence
Before departure, the pilot received a weather briefing that included thunderstorms, heavy rain, a severe thunderstorm watch with hail and wind gusts up to 65 knots, and a SIGMET (31c). The pilot filed an IFR flight plan and took off at 1148 CST. While en route at 15,000 feet MSL, the pilot requested and received clearance to divert 10° left to avoid "some clouds." Shortly after, air traffic control observed the aircraft about 500 feet high and reminded the pilot to maintain 15,000 feet. The pilot acknowledged, but no further communication was received.
An in-flight breakup occurred, and the aircraft crashed. The left outboard wing panel separated due to a positive overload failure and was found about one mile from the main wreckage. No preimpact fatigue was detected. A witness reported seeing the aircraft descending out of the clouds and also observed a funnel cloud in the area before the accident. Both occupants were killed.
Investigation Findings
The investigation determined that the pilot allowed the aircraft to exceed its design stress limits after encountering adverse weather. Factors identified were the pilot's improper evaluation of the weather and the adverse weather conditions themselves.