and observed the instructor's door disengaged and flapping in the spin. He reached back, pulled the door closed, and discovered all the vibrations, banging and noise stopped. Satisfied, he recovered from the spin, landed, and fueled the airplane. He also realized his instructor had been holding the door during their practice spin entries and recoveries, and never mentioned this door quirk. In later years, Crossfield often cited his curiosity about this solo spin anomaly and his desire to analyze what was going on and why it happened, as the start of his test pilot career. Over the next five years, he flew nearly all of the experimental aircraft under test at Edwards, including the X-1, XF-92, X-4, X-5, Douglas D-558-I Skystreak, and the Douglas D-558-II Skyrocket. During one of his X-1 flights, the cockpit windows completely frosted and Crossfield was literally flying blind. Ever resourceful, he removed a loafer, took off his sock, and created a peep hole to reference his chase plane wingman all the way to landing. On November 20, 1953, he became the first to fly at twice the speed of sound as he piloted the Skyrocket to a speed of 1,291 mph (2,078 km/h, Mach 2.005). The Skyrocket D-558-II surpassed its intended design speed by 25 percent on that day. With 99 flights in the rocket-powered X-1 and D-558-II, Crossfield had—by a wide margin—more experience with rocketplanes than any other pilot in the world by the time he left Edwards to join North American Aviation in 1955. In September 1954, Crossfield was forced to make a deadstick landing in the North American F-100 Super Sabre he was evaluating at the High-Speed Flight Station (now the Neil A. Armstrong Flight Research Center), a feat which North American's own test pilots doubted could be done, as the F-100 had a high landing speed. Crossfield made a perfect approach and touchdown, but was unable to bring the unpowered aircraft to a halt in a safe distance, and was forced to use the wall of the NACA hangar as a makeshift brake after narrowly missing several parked experimental aircraft ("with great precision," as he later wryly joked). Crossfield was uninjured, and the F-100 was later repaired and returned to service. Crossfield left NACA in 1955. North American Aviation career As chief engineering test pilot for North American, Crossfield played a major role in the design and development of the North