On August 21, 1961 a Douglas DC-8 broke the sound barrier at Mach 1.012 (660 mph/1,062 km/h) while in a controlled dive through 41,000 feet (12,497 m) and maintained that speed for 16 seconds. The flight was to collect data on a new leading-edge design for the wing, and while doing so, the DC-8 became the first civilian jet - and the first jet airliner - to make a supersonic flight.
The aircraft was DC-8-43 registered CF-CPG later delivered to Canadian Pacific Air Lines. The aircraft, crewed by Captain William Magruder, First Officer Paul Patten, Flight Engineer Joseph Tomich and Flight Test Engineer Richard Edwards, took off from Edwards Air Force Base in California, and was accompanied to altitude by an F-104 Starfighter supersonic chase aircraft flown by Chuck Yeager.
Douglas, more than any other company, made commercial air travel a reality. Douglas produced a succession of piston-engine aircraft (DC-2, DC-3, DC-4, DC-5, DC-6, and DC-7) through the 1930s, 1940s, and 1950s.
I mid 1952 Douglas secretly began jet transport project studies and by mid-1953 these had developed into a form similar to the final DC-8; an 80-seat, low-wing aircraft with four Pratt & Whitney JT3C turbojet engines, 30į wing sweep, and an internal cabin diameter of 11 feet (3.35 m) to allow five-abreast seating. Maximum weight was to be 190,000 lb (86 metric tons), and range was estimated to be about 3,000-4,000 miles (4,800-6,400 km).
The DC-8 was announced in July 1955. Four versions were offered to begin with, all with the same 150-foot-6-inch (45.87 m) long airframe with a 141-foot-1-inch (43.00 m) wingspan, but varying in engines and fuel capacity, and with maximum weights of about 240,000-260,000 lb (109-118 metric tons). Douglas steadfastly refused to offer different fuselage sizes. The maiden flight was planned for December 1957.