Boeing 707 lb (57.8 kN) with water injection. Maximum takeoff weight was 247,000 lb and first flight was on December 20, 1957. Major orders were the launch order for 20 707-121 aircraft by Pan Am and an American Airlines order for 30 707-123 aircraft. The first revenue flight was on October 26, 1958; 56 were built, plus seven short-bodied −138s; the last −120 was delivered to Western in May 1960. The 707-138 was a −120 with a fuselage 10 ft shorter than the others, with 5 ft (three frames) removed ahead and behind the wing, giving increased range. Maximum takeoff weight was
Boeing 707 also smaller and slower than the 707. Several major airlines committed only to the (second place in the production race) Douglas DC-8. Douglas Aircraft was the more established and preferred (by airlines and their passengers) maker of passenger aircraft at the time. Douglas had correctly decided to await the validation of a larger and more fuel efficient engine (JT4A from Pratt & Whitney), and to design a larger and longer range aircraft around this engine. To stay competitive, Boeing made a late and costly decision to redesign and enlarge the 707's wing to help increase range and payload. The new