Boeing 707

The Boeing 707 is a landmark American long-range, narrow-body airliner. It was the first jetliner produced by Boeing Commercial Airplanes. While it was not the very first commercial jet in service, it was the first to become widespread. Because of its massive success, the 707 is often credited with beginning the Jet Age. This aircraft helped establish Boeing as a dominant manufacturer in the global aviation industry. Its design influence can still be seen in modern aircraft like the 737 and 757.

The 707 is a swept-wing quadjet, meaning it has four engines. These engines are podded, which means they hang in separate containers under the wings. The wings are swept back at an angle of 35 degrees. This specific shape helps the aircraft fly at high speeds. The wings also serve a vital purpose by acting as fuel tanks for long trips.

To help with stability, Boeing eventually added a taller tail fin and a ventral fin. They also installed a yaw damper, which is a system that helps prevent unstable flying motions. Early models also featured Krueger flaps along the leading edge of the wing. These flaps were added to prevent the plane from stalling during takeoff or landing.

Boeing developed many different versions of the 707 to meet different needs. The initial standard model was the 707-120, which used Pratt & Whitney JT3C turbojet engines. The 707-120B used the more efficient JT3D turbofan engine. A turbofan is an engine that uses less fuel while providing higher thrust.

For shorter trips, Boeing introduced the 720, which was a lighter, short-range variant. For long-distance travel, the 707-320 and 707-420 series were much longer. These models were stretched by 8 feet compared to the original -120. The 707-320C was a "convertible" model designed for both passengers and cargo. It featured a large fuselage door to make loading freight easier.

The history of the 707 began with the Boeing 367-80, also known as the "Dash 80." This prototype was a proof-of-concept for both military and civilian use. The project launched in 1952, and the Dash 80 first flew on July 15, 1954. During a test flight over Lake Washington, pilot Tex Johnston even performed a barrel roll in the prototype. The first production 707-120 took its maiden flight on December 20, 1957. Pan Am began regular service with the aircraft on October 26, 1958.

Boeing chose the 700-series numbering to distinguish these jets from their older propeller planes. They specifically chose the name "707" because marketing experts thought it sounded more appealing than "700." This new era of flight was made possible by the Pratt & Whitney JT3C engine. This engine provided much more power than previous generations of jet engines. This leap in power allowed engineers to design a much larger and safer aircraft.

One major challenge during development was a flying characteristic called "Dutch roll." This is an unstable motion where the plane rolls and yaws, or turns, at the same time. This instability was a result of the swept-wing design. In one accident, a trainee pilot's actions made this motion so violent that three engines were torn from the wings. To solve this, Boeing engineers improved the tail and the rudder. These modifications provided better directional stability to keep the plane steady.

The 707 had a massive impact on how many people could travel. The wider fuselage allowed for six-abreast economy seating. This design choice was made to compete with the Douglas DC-8. The 707-120B could carry 174 passengers in a single class. Other models, like the 707-320B, were powerful enough to fly nonstop from Europe to the United States West Coast. In total, Boeing produced 865 707s for various uses. This includes military versions like the E-3 Sentry and the C-137 Stratoliner.