Boeing 707 ushering in the Jet Age. It established Boeing as one of the largest manufacturers of passenger aircraft, and led to the later series of airliners with "7x7" designations. The later 720, 727, 737, and 757 share elements of the 707's fuselage design. The 707 was developed from the Boeing 367-80, a prototype jet first flown in 1954. A larger fuselage cross-section and other modifications resulted in the initial-production 707-120, powered by Pratt & Whitney JT3C turbojet engines, which first flew on December 20, 1957. Pan American World Airways began regular 707 service on October 26, 1958. Later derivatives included the
Boeing 367-80 707 fuselage with that width. By the time the Boeing company committed to production, the decision had been made to design the production model 707 as a six-abreast design, with a larger diameter fuselage, after C.R. Smith, CEO of American Airlines, told Boeing he wouldn't buy the 707 unless it was an inch wider than the then-proposed Douglas DC-8 passenger jet. This decision did not unduly delay introduction of the production model since the -80 had been largely hand-built, using little production tooling. By early 1952 the designs were complete and in April the Boeing board approved the program. Construction