What happened
On the night of the accident, Flight 250 was operating a multi-stop domestic cargo and passenger service from New Orleans to Minneapolis. After completing several intermediate stops, the aircraft departed Kansas City at 2255 hours under an IFR clearance, initially restricted to 5,000 feet due to traffic. During the flight, the crew communicated with Kansas City ARTCC regarding weather conditions and requested a deviation to the left of their assigned course.
While communicating with another aircraft, Flight 255, the crew received reports of light to moderate turbulence near Omaha. The final transmission from Flight 250 occurred at approximately 2308:30 hours. Witnesses on the ground reported seeing the aircraft enter a cloud shelf associated with an approaching thunderstorm line, followed by an aerial explosion and a fireball. The aircraft type crashed roughly 7.6 miles from Falls City, Nebraska, at an elevation of 1,078 feet. There were 42 fatalities in the accident.
Findings
Investigation into the crash determined that the aircraft suffered an in-flight structural failure triggered by extreme turbulence. The flight encountered intense wind shears produced by the outflow of a cold air mass from an approaching squall line. Although the weather system was forecasted, the airline's internal forecast underestimated the intensity and density of the thunderstorm line.
While the crew was aware of the potential for bad weather, they attempted to navigate through what appeared to be a lighter area using onboard radar. The investigation concluded that the intense vertical, lateral, and longitudinal forces from a sudden gust caused the fin and right tailplane to exceed their ultimate load limits. This structural failure led to a loss of control, causing the aircraft to pitch downward and eventually enter a flat spin before impact.