Background
At 0716, the pilot received a weather briefing from a Flight Service Station (FSS) specialist for a proposed takeoff at 1130. The briefer provided information on thunderstorms forecast in Georgia and Florida but did not provide information about forecast lines and clusters of thunderstorms in the South Carolina coastal plains and southeastern Georgia.
Flight and Weather
En route, the pilot was given information about Level III thunderstorms across the projected flight path by Beaufort and Savannah approach control. ATC radar data revealed that the aircraft flew the route contained in the flight plan clearance. Radio transmissions from the aircraft indicated that onboard weather radar was being used.
Accident Sequence
ATC radar data and radio communications indicated that the aircraft entered a thunderstorm, then made a 180° turn to exit the storm. Subsequently, the aircraft crashed, killing all five occupants.
Wreckage Examination
Examination of the wreckage revealed plastic deformation of the wings inboard of the engines in an upward direction. Both wings broke off outboard of the engines in a downward direction. The horizontal stabilizer and elevator were not recovered. Fuselage damage indicated that the horizontal stabilizer separated aft and down.
Probable Cause
The official probable cause of the accident was the pilot's inadequate weather evaluation and his continued flight into known adverse weather conditions. Contributing factors were the improper weather briefing by a flight service station specialist and the presence of Level III thunderstorms.