On this day 50 years ago - February 19, 1965 - Boeing formally launched its 737 with an order for 21 aircraft from Lufthansa. Like the 727 and the DC-9, the 737 would be powered by Pratt & Whitney's workhorse JT8D engine.
The 737-100 first flew in April 1967. It was designed to fit below the larger 727 and compete with the Douglas DC-9, BAC-11 and Fokker F-28 which were already in development. (See "This Day in History," Jan. 12, 2015). Boeing built only 30 737-100s, all for Lufthansa.
The aircraft was almost immediately stretched a bit over six feet into the 737-200. The plane adopted many features of the 727 in addition to the JT8Ds. For instance it used the same cross-section as the 727. Not only did it save development costs, it allowed for six-across seating compared to the five-across in the DC-9, BAC-111 and F-28.
Boeing built 1,114 737-200s before production ended in 1988.