Incident Overview
The aircraft was operating under an IFR flight plan and was level at 16,000 feet when radar and radio contact was lost.
Weather Conditions
Cloud tops in the accident area were reported at 18,000 feet. A pilot flying in the vicinity at the time noted that cloud tops of the buildups ranged from 16,000 to 20,000 feet and reported moderate unexpected turbulence, adding that updrafts in the area were very strong. Satellite imagery showed an east-west cloud band approximately 10 miles wide, which the aircraft's ground track was traversing during the minutes before and around the time of the accident.
Aircraft Performance
The onboard weather radar was found in the off position. According to Advisory Circular 00-6A, pilots should avoid severe thunderstorms by at least 20 miles and clear the top of a known or suspected severe thunderstorm by at least 1,000 feet altitude for each 10 knots of wind speed at the cloud top. The aircraft's calibrated airspeed (KCAS) was calculated at 141 knots, and indicated airspeed (KIAS) was 139 knots. The Pilot's Operating Handbook (POH) specified the maneuvering speed at gross weight as 135 KCAS and 133 KIAS.
Probable Cause
The probable cause was the pilot's inadvertent flight into adverse weather conditions. Contributing factors were the pilot's failure to use weather detection equipment and operation of the aircraft at airspeeds in excess of limitations.