What happened
On a flight departing from Chicago-Midway at 14:38 local time, an aircraft bound for Miami was carrying 57 passengers and six crew members. While the flight was cruising at 18,000 feet over southern Indiana, the plane entered a sudden dive. The aircraft subsequently struck a snow-covered field located east of Tell City, resulting in a massive explosion. Portions of debris were also recovered from a nearby wooded area. The impact caused the aircraft to disintegrate, and all 63 occupants were killed in the accident. No distress signals were transmitted by the crew before the crash occurred.
Findings
Investigations into the accident determined that the right wing separated from the aircraft during flight. This structural failure was triggered by flutter caused by oscillations within the outboard nacelles. The investigation also identified two contributing factors: a lack of sufficient structural stiffness and the aircraft's encounter with an area of intense clear air turbulence.