On December 8, 2005, the airplane slid off a runway at Midway Airport in Chicago while landing in a snowstorm and crashed into automobile traffic, killing a six-year-old boy.

The plane circled over a small area in northwest Indiana several times before attempting to land in a snowstorm[1]: 1  that had reduced visibility to less than one mile.

Chicago Fire Department commissioner Cortez Trotter said that the aircraft would not be removed from the intersection until the NTSB gave clearance to do so following its on-site investigation.

Flight data recorder information reveals that the thrust reversers were not deployed until 18 seconds after touchdown, at which point there was only about 1,000 feet (300 m) of usable runway remaining.

"[12] Alternately, the crew could have held in the air, waiting for the weather to improve, or they could have diverted to another airport such as Chicago O'Hare International, which had substantially longer runways just 10 minutes away.

The NTSB identified the psychological pressure to complete their assigned task as one of the factors contributing to the crew's decision to land at Midway despite unfavorable conditions.

Cockpit voice-recorder transcripts indicate that the pilots had been concerned about the weather and, before landing, jokingly alluded to the movie Airplane!, saying, "I picked a bad day to stop sniffin' glue.

[citation needed] The pilots stated that, based on the calculations that the crew had entered into the on-board performance computer (OPC), they believed that they could land and stop safely.

However, investigators determined that the OPC based its stopping margins on two assumptions: that the tailwind would be slower than it turned out to be and that the thrust reversers would be deployed when landing.

[citation needed] The NTSB determined that the probable cause was the pilots' failure to use available reverse thrust promptly to safely decelerate or stop after landing, which resulted in a runway overrun.

This failure occurred because the pilots' first experience and lack of familiarity with the airplane's autobrake system distracted them from thrust-reverser usage during the challenging landing.

Contributing to the accident were Southwest Airlines' 1) failure to provide its pilots with clear and consistent guidance and training regarding company policies and procedures related to arrival landing distance calculations; 2) programming and design of its on-board performance computer, which did not present critical assumption information despite inconsistent tailwind and reverse thrust assessment methods; 3) plan to implement new autobrake procedures without a familiarization period; and 4) failure to include a margin of safety in the arrival assessment to account for operational uncertainties.

Contributing to the severity of the accident was the absence of an engineered materials arrestor system, which was needed because of the limited runway-safety area beyond the departure end of Runway 31C.

The accident renewed debates on the need for, and feasibility of, an engineered materials arrestor system, or EMAS, at Chicago Midway, given the lack of adequate overrun areas and the surrounding residential neighborhoods.

The previous major incident was in 2000, when Southwest Airlines Flight 1455 overran a runway in Burbank, California, injuring 43 and narrowly avoiding a catastrophe; the aircraft ended up outside a Chevron gas station.