A correction of the originally published version appears in red. There are two kinds of wind detection systems at airports in the United States, and one costs 54 times as much as the other. Little Rock National Airport, Adams Field, has the cheaper kind. The Little Rock airport's wind shear alert system has six wind gauges atop poles 50 feet to 150 feet high.
Wind shear is a sharp change in wind direction or speed that can occur during strong thunderstorms.
The system alerts the air traffic control tower when a wind change of 13 knots, or about 15 mph, occurs between one wind gauge and another. Ill. A storm had just passed over the airport when the plane tried to land, and another had almost arrived. Weather with brutal gusts, lightning and hail is a possible factor in the crash. National Transportation Safety Board officials have said that the cockpit crew was well-informed about the severe weather in Little Rock. But a pilot for Delta Air Lines, who spoke on condition of anonymity, said he'd prefer more advance warning than that from wind shear alert systems like the one at the Little Rock airport.