Accident Overview
At 1032:27, air traffic control (ATC) instructed the pilot of an airplane in cruise flight at approximately 7,000 feet mean sea level (msl) to descend to 3,000 feet msl. The pilot acknowledged the instruction. ATC's last radar contact with the airplane occurred at 1032:53, at which time the airplane's altitude was about 6,500 feet msl. No distress call was made, and the pilot did not report any mechanical difficulties.
Witness Observations
Witnesses reported hearing the airplane while it was inside clouds for about one minute, with the engine sound becoming progressively louder. As the airplane descended out of the clouds, it was observed in a nose-down attitude of approximately 45 degrees and spinning rapidly. The oscillating engine noise intensified during the descent. Witnesses noted that part of one wing appeared to be missing. The airplane then suddenly pitched straight down and impacted the ground in a steep, nose-down attitude.
Aircraft Examination
Post-accident inspection of the airplane revealed that the left wing's fracture surfaces were consistent with an overstress fracture. No deficiencies were found that would have precluded normal operation.
Weather Conditions
Weather radar depicted a narrow line of echoes in the vicinity of the accident site. A band of cumulus clouds was present over or immediately near the accident site at the time of the accident, with cumulonimbus-type clouds to the west and southwest. The weather radar spectrum width indicated an area of shear between 12 and 24 knots along the last known position of the accident airplane and the accident site, suggesting significant wind velocities and turbulence along the flight track.