But to pilots, his bravery and skill made the Mach 1 flight in the Bell X-1 Glamorous Glennis only one of his many contributions to aviation. A cadre of experimental test pilots who were his companions at Edwards Air Force Base alongside him as he spent the years following the famous flight further expanding the envelope, and proving what was possible as far as speed. He contributed to the redesign of the F-100A by testing the prototype YF-100 and determining its flight control deficiencies warranted such attention. He evaluated a Russian MiG 15 that had fallen into American hands—and on December 12, 1953, took the Bell X-1A to Mach 2.44 in the skies above Edwards. On that fateful flight, he encountered “inertia coupling,” which sent the rocket-powered airplane into violent roll and pitch motions after he cut the engine following the speed run at 76,000 ft. Yeager regained control at 25,000 ft—cementing his legacy as the world’s fastest pilot, and unquestionably one of the most skilled.