- US Air Force officer and test pilot Chuck Yeager, who in 1947 became the 1st pilot in history to have surpassed the speed of sound in level flight, has passed away.
- As a test pilot, on October 14, 1947, Yeager became the first human to officially break the sound barrier, when he flew the experimental Bell X-1 aircraft at Mach 1 (speed of sound) at an altitude of 45,000 ft (13,700 m). Level flight means flying at a constant altitude, not going up and down.