The Southwest Airlines Boeing 737-700 that overran Chicago Midway airport’s runway 31C onto a road landed about 620m (2,000ft) along the 1,990m snow-contaminated runway with a tailwind, says the National Transportation Safety Board (NTSB).
The crew took 18s to apply reverse thrust in the 8 December accident, but the NTSB’s calculations suggest that even if they had selected it immediately, the aircraft would not have stopped within the remaining runway surface. The aircraft ran through a blast fence and perimeter fence before hitting two cars on a road, killing one occupant and severely injuring a second.
The reason for using runway 31C, despite the known 10kt (18.5km/h) tailwind component, instead of its into-wind reciprocal 13C, is that the approach decision minima are higher for 13C and would have made landing impossible because of the snow and poor visibility, says the NTSB.
Source: Flight International