It was in 1966, when American Airlines expressed the need of a new airliner. This aircraft should give the passengers the same comfort as the Boeing B747, yet, it was supposed to be small enough to operate from New York La Guardia whereas it should have a passenger capacity of about 250. At the same time the new aircraft was meant to fly not only long range and nevertheless operate as efficiently as the Boeing B747 . The result of these requirements was a concept of an aircraft with a relatively short but wide fuselage and three engines, one of which located in the tail-unit. To meet the takeoff expectations for La Guardia and also for the hot Denver, the leading edge flaps could be extended into three positions. Also, the wing profile changes very much from the wingtips to the wing base, to guarantee an optimum of efficiency at slow speed as well as cruising speed. The passenger windows were 30% bigger than in any other wide body at this time and the designers already thought of different versions of the DC10 even before the first DC10 flew.Even though, in 1968, American Airlines ordered 25 DC10s (and held options for 25 others) the financial breakthrough was not yet reached: The DC10 faced the direct competition of the Lockheed L1011, which seemed to be more successful. But in 1968, United ordered 30 DC10s and also Northwest decided in favor of the DC10. In 1971, an American Airlines DC10-10 flew the first passengers from Los Angeles to Boston. When the new Pratt & Whitney JT9D-20 engines were developed, the long range version DC10-40 was born. Nevertheless, most DC10-orders were DC10-30, the long range version, powered by CF6 engines, featured the same longer wings as the DC10-40, greater fuel capacity and a third gear system under the fuselage to account for the higher weight of up to 259,5 t. With the DC10-30F, there was also a pure cargo version, the DC10-30CF could be changed from a passenger to a cargo aircraft. These where advantages which the Lockheed TriStar couldn't offer and the DC10 set off to become the most desirable airplane for airlines in that time with more than 350 orders from all over the world... But in the first months of airline operation, several accidents occurred: Engine failures and failures at the cargo door bolts did not put an end to the airline orders. But when on May 25th, 1979, an American Airlines DC10-10 lost (it fell off) the entire engine #1 during take off in Chicago O'Hare and crashed, the FAA withdrew the admission for the DC-10. Even though, after a long examination the maintenance procedures where blamed for the Chicago crash, McDonnell Douglas never came out with a new version of the DC10. Longer and shorter versions had been planed but the only new DC10 was called KC-10, a military version for the USAF. Today, used DC-10 are being converted into modern MD-10 cargo aircraft for Federal Express.