Boeing 707
The Boeing 707 was the first commercially successful jet airliner: a four-engined, swept-wing transport developed from Boeing's privately funded Dash 80 prototype of 1954. First flown in December 1957, it entered service with Pan American in October 1958 and made jet travel routine on domestic, transcontinental and transatlantic routes through the 1960s and 1970s. Its widened, six-abreast fuselage set the pattern for Boeing's later narrow-body airliners, and military versions kept the family in production until 1991, long after the airliners retired.
Why It Mattered
Boeing was known chiefly as a builder of military aircraft when, in the early 1950s, it spent $16 million of its own capital on a prototype jet transport that nobody had ordered. The Air Force had passed on the idea, and the company was betting that a jet which had flown and proven itself would find its buyers afterwards. The bet paid off: the developed aircraft, the 707, became America's first jet airliner and the machine credited with inaugurating the jet age in commercial travel. Nothing sold it like the prototype's public appearances: at the Gold Cup hydroplane races on Lake Washington in August 1955, before airline representatives gathered to watch a flypast, test pilot Alvin "Tex" Johnston barrel-rolled the Dash 80 over the lake — in the National Air and Space Museum's account, a display that readily convinced the industry to buy.
Design Notes
The project began as studies of improved versions of the C-97 piston transport, but by the 80th iteration the design bore no resemblance to it; Boeing kept the 367-80 designation anyway, and the aircraft became known as the Dash 80. Work formally started on May 20, 1952, mating a large cabin based on the C-97's dimensions with a low wing swept at 35 degrees, its design drawn from the B-47 and B-52 bomber wings but considerably stiffer. Four Pratt & Whitney JT3 turbojets, each producing 10,000 pounds of thrust, were mounted on struts beneath the wings. For production, Pan Am insisted the fuselage be widened to seat six passengers abreast instead of five; that wider cross-section became the standard design for all of Boeing's subsequent narrow-body airliners. Later variants added fuel capacity and replaced the turbojets with more efficient turbofans, giving the 707-300 Intercontinental series the legs to fly nonstop across the Atlantic with a full payload.
Operational History
The Dash 80 first flew on July 15, 1954, some 100 miles per hour faster than the de Havilland Comet and with more than twice its range. The Air Force was the design's first customer, taking a widened version as the KC-135A tanker; 732 KC-135s were built in all. Pan American ordered 20 707s in 1955, hedging with 25 of Douglas's rival DC-8s, and opened commercial 707 service on October 26, 1958, with a New York-to-Paris flight that took 8 hours and 41 minutes, including a refuelling stop in Gander. Domestic jet service began two months later with a 707 borrowed from Pan Am, and in January 1959 American Airlines began flying its own 707s, opening the first regularly scheduled transcontinental jet service that year. Boeing built 855 707s, of which 725 were bought by airlines worldwide; the type and the DC-8, both bigger, faster and more profitable than the Comet and Tu-104 that preceded them, set the pattern of air transport for the 1960s. Airliner production wound down in the late 1970s, though the production line itself remained open for purpose-built military variants until 1991.
Afterlife
The last scheduled 707 flight in the United States was a Trans World Airlines service from Miami to New York in 1983. Airlines elsewhere kept the type longer, and Iran's Saha Airlines flew 707s in passenger service until 2013, after which commercial use of the 707 ceased. In uniform the family lasted far longer: military derivatives built on the 707, among them the E-3 Sentry airborne warning aircraft, the E-6 Mercury and the E-8 Joint STARS, kept it in service decades after the airliners were retired. The Dash 80, meanwhile, worked on as an experimental testbed until its retirement in 1972 — at one point it carried three different engine types in its four nacelles — before Boeing donated it to the Smithsonian. It is on display today at the National Air and Space Museum's Steven F. Udvar-Hazy Center in Chantilly, Virginia.