The Boeing 707 is an American, long-range, narrow-body airliner, the first jetliner developed and produced by Boeing Commercial Airplanes.
Developed from the Boeing 367-80 prototype first flown in 1954, the initial first flew on December 20, 1957. Pan Am began regular 707 service on October 26, 1958.
With versions produced until 1979, the 707 was a swept wing, quadjet with podded engines. Its larger fuselage cross-section allowed six-abreast economy seating, retained in the later 720, 727, 737, and 757 models.
Although it was not the first commercial jetliner in service, the 707 was the first to be widespread, and is often credited with beginning the Jet Age. It dominated passenger air transport in the 1960s, and remained common through the 1970s, on domestic, transcontinental, and transatlantic flights, as well as cargo and military applications. It established Boeing as a dominant airliner manufacturer with its 7x7 series.
The initial, was powered by Pratt & Whitney JT3C turbojet engines. The shortened, long-range and the more powerful entered service in 1959. The longer-range, heavier 707-300/400 series has larger wings and is stretched slightly by . Powered by Pratt & Whitney JT4A turbojets, the 707-320 entered service in 1959, and the with Rolls-Royce Conway turbofans in 1960.
The 720, a lighter, short-range variant, was also introduced in 1960. Powered by Pratt & Whitney JT3D turbofans, the 707-120B debuted in 1961 and the 707-320B in 1962. The 707-120B typically flew 137 passengers in two classes over , and could accommodate 174 in one class. With 141 passengers in two classes, the 707-320/420 could fly and the 707-320B up to . The 707-320C convertible passenger-freighter model entered service in 1963, and passenger 707s have been converted to freighter configurations. Military derivatives include the E-3 Sentry airborne reconnaissance aircraft and the C-137 Stratoliner VIP transport.
In total, 865 Boeing 707s were produced and delivered, not including 154 Boeing 720s.
Development
Model 367-80 origins
During and after World War II, Boeing was known for its military aircraft. The company had produced innovative and important bombers, from the B-17 Flying Fortress and B-29 Superfortress, to the jet-powered B-47 Stratojet and B-52 Stratofortress, but its commercial aircraft were not as successful as those from Douglas Aircraft and other competitors. As Douglas and Lockheed dominated the postwar air transport boom, the demand for Boeing's offering, the 377 Stratocruiser, quickly faded with only 56 examples sold and no new orders as the 1940s drew to a close. That venture had netted the company a $15 million loss. During 1949 and 1950, Boeing embarked on studies for a new jet transport and saw advantages with a design aimed at both military and civilian markets. Aerial refueling was becoming a standard technique for military aircraft, with over 800 KC-97 Stratofreighters on order. The KC-97 was not ideally suited for operations with the USAF's new fleets of jet-powered fighters and bombers; this was where Boeing's new design would win military orders.
As the first of a new generation of American passenger jets, Boeing wanted the aircraft's model number to emphasize the difference from its previous propeller-driven aircraft, which bore 300-series numbers. The 400-, 500- and 600-series were already used by their missiles and other products, so Boeing decided that the jets would bear 700-series numbers, and the first would be the 707. The marketing personnel at Boeing chose 707 because they thought it was more appealing than 700.
The project was enabled by the Pratt & Whitney JT3C turbojet engine, the civilian version of the J57 that yielded much more power than the previous generation of jet engines and was proving itself with the B-52. Freed from the design constraints imposed by limitations of late-1940s jet engines, developing a robust, safe, and high-capacity jet aircraft was within reach for Boeing. Boeing studied numerous wing and engine layouts for its new transport/tanker, some of which were based on the B-47 and C-97, before settling on the 367-80 "Dash 80" quadjet prototype aircraft. Less than two years elapsed from project launch in 1952 to rollout on May 14, 1954, with the first Dash 80 flying on July 15, 1954. The prototype was a proof-of-concept aircraft for both military and civilian use. The United States Air Force was the first customer, using it as the basis for the KC-135 Stratotanker aerial refueling and cargo aircraft.