On October 25, 1999 golfer Payne Stewart's plane crashed near Mina, South Dakota. Stewart chartered a Lear jet to fly from Orlando, Florida, to Dallas, Texas. Early in the flight, the aircraft was climbing on autopilot but suddenly lost cabin pressure. Stewart and the others on board blacked out from hypoxia, a lack of oxygen.
Still on autopilot, the aircraft continued climbing past its assigned altitude. Then failed to make the westward turn toward Dallas, and continued on its northwestern path, eventually running out of fuel over South Dakota. When ground control determined something catastrophic had happened. A U.S. Air Force F-16 test pilot from Eglin Air Force Base in northern Florida was in the air nearby.
The pilot intercepted the plane and made a visual inspection of the Learjet, finding no visible damage, but he could not see any flight control movement. About 3 hours into the flight, the jet was still unresponsive. So two F-16s from the Oklahoma Air National Guard were directed by the Minneapolis Air Traffic Control to intercept. They reported, "We're not seeing anything inside. He is not reacting, moving or anything. He should be able to have seen us by now."
There was some speculation in the media that military jets were prepared to shoot down the Learjet if it threatened to crash in a heavily populated area, but the Air Force said shooting down the plane was never an option. The Learjet eventually ran out of fuel and without engine power, the autopilot attempted to maintain altitude, which caused a drop in airspeed until it approached a stall.
The Learjet began a right turn and severe spiraling descent until it crashed. The total flight time was just under 4 hours. Hypoxia almost certainly claimed the lives of the passengers long before that impact.
Help comes from Dr. Brad Tennant, professor of history at Presentation College.