Radar Data
Radar track data showed the aircraft made a normal climb on course from the airport (elevation 4,488 ft MSL) to 9,400 ft MSL. It then executed a left turn of about 90 degrees, climbing to 9,700 ft MSL as indicated by the next-to-last radar target. Twenty-nine seconds later, the final radar target showed an altitude of 6,900 ft MSL.
Witness Observations
Witnesses sighted the aircraft spinning with pieces coming off before it struck the ground.
Weather Conditions
A weather study indicated convective clouds in the area from 2,000 ft to 10,000 ft MSL.
Investigation Findings
Investigation revealed that the right wing and empennage separated in an aerodynamic overload failure mode. The maximum design maneuvering speed was calculated to be 123 knots at the existing aircraft weight.
Probable Cause
The circumstances indicate that the pilot lost control of the aircraft while maneuvering to avoid or reverse course out of clouds, overstressing the airframe during the recovery attempt.