The Douglas DC-8 (sometimes McDonnell Douglas DC-8) is an early long-range narrow-body jetliner designed and produced by the American Douglas Aircraft Company. Work began in 1952 toward the United States Air Force's (USAF) requirement for a jet-powered aerial refueling tanker. After losing the USAF's tanker competition to the rival Boeing KC-135 Stratotanker in May 1954, Douglas announced in June 1955 its derived jetliner project marketed to civil operators. In October 1955, Pan Am made the first order along with the competing Boeing 707, and many other airlines soon followed. The first DC-8 was rolled out in Long Beach Airport on April 9, 1958, and flew for the first time on May 30. Following Federal Aviation Administration (FAA) certification in August 1959, the DC-8 entered service with Delta Air Lines on September 18. Permitting six-abreast seating, the four-engined, low-wing jet aircraft was initially produced in four 151 ft (46 m) long variants. The DC-8-10 was powered by Pratt & Whitney JT3C turbojets, and had a 273,000 lb (124 t) MTOW; the DC-8-20 had more powerful JT4A turbojets, for a 276,000 lb (125 t) MTOW. The intercontinental models had more fuel capacity, and had an MTOW of up to 315,000 lb (143 t); it was powered by JT4As for the Series 30, and by Rolls-Royce Conway turbofans for the Series 40. The Pratt & Whitney JT3D powered the later DC-8-50 and Super 60 (DC-8-61, -62, and -63) as well as freighter versions, and reached a MTOW of 325,000 lb (147 t). A stretched DC-8 variant was not initially considered, leading some airlines to order the competing Boeing 707 instead.The improved Series 60 was announced in April 1965. The DC-8-61 was stretched by 36 ft (11 m) for 180–220 seats in mixed-class and a MTOW of 325,000 lb (147 t). It first flew on March 14, 1966, was certified on September 2, 1966, and entered service with United Airlines in February 1967. The long-range DC-8-62 followed in April 1967, stretched by 7 ft (2.1 m), could seat up to 189 pass