Boeing 377 in 1950 and the first order for the 707 in 1955, Boeing was shut out of the commercial aircraft market. In the mid-1950s technology had advanced significantly, which gave Boeing the opportunity to develop and manufacture new products. One of the first was the guided short-range missile used to intercept enemy aircraft. By that time the Cold War had become a fact of life, and Boeing used its short-range missile technology to develop and build an intercontinental missile. In 1958, Boeing began delivery of its 707, the United States' first commercial jet airliner, in response to the British De
Boeing 707 The 707-320B had the application of the JT3D turbofan to the Intercontinental, but with aerodynamic refinements. The wing was modified from the −320 by adding a second inboard kink, a dog-toothed leading edge, and curved low-drag wingtips instead of the earlier blunt ones. These wingtips increased overall wingspan by 3.0 ft. Takeoff gross weight was increased to . The 175 707-320B aircraft were all new-build; no original −320 models were converted to fan engines in civilian use. First service was June 1962, with Pan Am. The 707-320B Advanced is an improved version of the −320B, adding the three-section leading-edge flaps