McDonnell Douglas began studies in 1978 of an aircraft to replace the DC-10 on the Long Beach production line. The result was the MD-11 tri-jet of 1985. This is essentially a stretched DC-10, but with a new outer wing incorporating winglets, a new tail, a two-pilot EFIS flight deck, and the choice of either General Electric CF6-80C or Pratt &, Whitney PW4460 engines. (In June of 1983 the company adopted a new system of MD designations, breaking away from the old Douglas Commercial (DC) system.) The MD-11P, all passenger version, is able to carry 293 passengers, or 405 passengers in single economy-class seating. It has a maximum level speed at 27,000 feet of 597 mph, service ceiling of 32,600 feet, and range of 5,760 miles.