History of the Boeing 707

In the early 1950s, Boeing was concentrating its future transport studies on advanced jet or turboprop versions of the C-97 Stratocruiser. Feeling the heat from across the ocean with the success of the British Comet, Boeing was convinced that the answer had to be a jet.

To design a prototype, Boeing engineers first searched through their blueprints to see if they could piece together a jetliner from wings, tails, and fuselages already on hand. The initial designation, Model 367-64, represented the 64th variation in the Stratocruiser series. In fact, it did resemble the older plane with its large fuselage and modestly sweptback wings, each of which was fitted with a single pod containing two engines. The engine arrangement had been copied from Boeing's jet bombers of the time, as had much of the original design. By late 1951, all of the 367-series studies were centered around the use of four Pratt & Whitney JT3 turbojets, the civilian version of the J57 turbojet that appeared on Boeing's B-52 Stratofortress. Studies continued searching for the right combination and arrangement of wing, engines, and landing gear. Although further modifications were leading the aircraft increasingly away from the Stratocruiser concept, Boeing continued to number the new designs as if they still bore a resemblance to the old piston-engined plane. This was in part for the sake of secrecy. Should any of Boeing's competitors follow what they were doing, it would appear as if they were simply attempting to improve upon the design of the existing C-97.

In early 1952, the 367-80 configuration appeared to Boeing to be the best that could be achieved at that time. The wing featured a 35Ð'o sweep, carried the engines in separate, widely spaced pods that hung well forward and below the wing, and rested on two four-wheel main landing gear that retracted inward to occupy large bays in the fuselage. The wings were mounted low on the fuselage and incorporated high-speed and low-speed ailerons as well as a sophisticated flap and spoiler system.

To this point, Boeing had not secured any sales to either the United States Air Force or any airlines. Airlines weren't anxious to enter the jet age just yet. Piston engine airliners were profitable, the recent Comet disasters indicated that more development was necessary, and the high cost of jet airliners and their required infrastructure all conspired against Boeing. President Bill Allen announced on May 20, 1952 that, despite this, Boeing would go it alone and build the prototype at a cost of $16 million. At that time, it was the largest risk ever accepted by an aircraft manufacturer, and one that could have easily put Boeing into bankruptcy if either entity declined to purchase. The gamble would later payoff big.

The new Jetliner was proudly rolled out from the Boeing plant where it was built near Seattle in May 1954 to a large crowd of Seattle area residents. By this time, the company type numbers had entered the 700s and the aircraft became known as the 707. The 707 first took to the air on July 15, 1954 with test pilot A. M. 'Tex' Johnston at the controls. Test flights would last throughout the rest of the year into 1955 overcoming problems with the engines, brake system, and various other smaller issues. Interspersed among the test flights were demonstration rides for Air Force officials and airline executives from around the globe. For most, it was their first exposure to the smooth power of jet flight. Many were actually allowed to take over the controls to get a feel for the aircraft.

In March of 1955, Boeing signed its first customer, the United States Air Force. The already aging KC-97 tankers could no longer keep up with the jet fighters and bombers of the day, and a replacement was needed. An initial order was placed for a fleet of 29 jet tankers, the first of which would enter service in 1957 as the KC-135 Stratotanker.

With an initial order secured by the military, Boeing turned its