___Flying for the National Advisory Committee for Aeronautics (NACA), a civilian test pilot had just scored a major triumph. In a masterful performance on 20 November, he had piloted the sweptwing Douglas D-558-II Skyrocket to a speed of 1,291 mph in a shallow dive at 62,000 feet and thereby became the first man to fly at twice the speed of sound – but just barely, at Mach 2.005. It was a remarkable achievement, all the more so because the Skyrocket had not originally been designed to fly much beyond Mach 1.5. The D-558-II was a U.S. Navy airplane, and following a civilian test pilot's flight, it appeared that the Navy and the NACA were going to enjoy “bragging rights” when the 50th anniversary of powered flight was celebrated on 17 December. ___There was another rocket-powered airplane just entering test down the flight line at Edwards, however, which had been designed to fly well beyond Mach 2. That airplane was the Air Force’s Bell X-1A, a “stretched” second-generation version of the X-1 which incorporated a low-pressure turbopump fuel system, increased fuel capacity which would permit 4.65 minutes of full four-chamber burn time for its 6,000 pound thrust XLR-11 engine, as well as a host of other improvements.