McDonnell Douglas built the widebody MD-11 trijet as a successor to the DC-10, from which it was derived. Seating frm 223 to 410, it was made in four versions: all-passenger; all-freight; convertible freighter; and the combi, with passengers and freight on the main deck and additional freight below the deck. Advances in aerodynamics, propulsion, aircraft systems, cockpit avionics and interior design contribute to the performance and operating economy of all MD-11 models. Aerodynamic improvements include winglets and a redesigned wing trailing edge, a smaller horizontal tail with integral fuel tanks, and an extended tail cone. These features reduce drag, save fuel and add range. Boeing ended production of the plane in 2000 after 200 planes were built. The last MD-11 was delivered Feb. 22, 2001.