Bell Aircraft X-1A Seen at the National Aviation Show in Dayton, Ohio in September, 1954. It was in this aircraft on December 12, 1953 that Major Chuck Yeager set a new speed record of Mach 2.44, 1,650 mph, at 75.000 feet. The aircraft subsequently tumbled out of control due to inertia coupling, and fell 51,000 feet before Major Yeager was able to regain control and land safely. T X-1A was lost on August 8, 1955, when an in-flight explosion occurred just prior to being launched from a B-29, and the aircraft was jettisoned in the Muroc desert.