What happened
On December 8, 2005, Southwest Airlines operated flight 1248, a scheduled service traveling from Baltimore to Chicago, with subsequent connections to Salt Lake City and Las Vegas. The aircraft, identified as Boeing 737-7H4 with registration N754SW, was on its final approach to Midway International Airport in Chicago under severe winter weather conditions characterized by heavy snowfall.
Upon attempting to land, the aircraft failed to stop within the available runway distance. It overran the end of the runway and collided with a line of automobiles waiting on a nearby roadway. The impact resulted in significant damage to both the aircraft and the vehicles involved. Tragically, one person was killed: a six-year-old boy who was inside one of the struck cars. Other passengers on board and individuals in the affected vehicles sustained injuries.
Investigation
The National Transportation Safety Board (NTSB) conducted an investigation into the incident to determine the causes of the runway excursion. Investigators examined weather data, flight data recorder information, and witness statements. The inquiry focused on the aircraft's performance during landing in adverse weather, specifically evaluating braking effectiveness and reverse thrust usage.
Findings
The investigation concluded that the primary factor contributing to the accident was the excessive speed at touchdown. The crew failed to maintain the appropriate approach speed for the wet and snowy runway conditions. Additionally, the use of reverse thrust was deemed insufficient to stop the aircraft safely given the reduced friction on the runway surface. These factors combined led to the overrun and subsequent collision with ground traffic.