 A Learjet 24B, N234CM, departed Memphis International Airport on December 16, 1988, heading for Addison, Texas with two crew aboard, including NASA astronaut-candidate Susan Reynolds. After it flew past its destination, the aircraft was intercepted by an Air Force T-38 Talon from the 560th Flying Training Squadron at Randolph AFB, but the pilot was unable to contact the crew. He reported that the cockpit windows appeared to have frost on the inside. The Lear entered Mexican airspace. After exhausting its fuel supply, it entered a spin and crashed near Cuatro Ciénegas in the northern state of Coahuila. The two pilots were killed.
