Editing Boeing 707 (section)

===707-320B===
[[File:CAAC Boeing 707.jpg|thumb|The -320B, powered by [[JT3D]] turbofans]]

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.<ref name="airlinercafe.com"/> These wingtips increased overall wingspan by 3.0&nbsp;ft (0.9 m). Takeoff gross weight was increased to {{cvt|328000|lb|kg|sigfig=3}}. 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 already seen on the -320C. These reduced takeoff and landing speeds and altered the lift distribution of the wing, allowing the ventral fin found on earlier 707s to be removed. From 1965, -320Bs had the uprated -320C undercarriage allowing the same {{cvt|335000|lb|kg|sigfig=3}} MTOW. These were often identified as 707-320BA-H.