Just like all other MD's that were built by >McDonnel Douglas, the MD-11 is no completely new plane, but an almost completely redesigned existing model. The predecessor of the MD-11 isn't hard to find: the number of engines alone is enough information. But before the DC-10 was classified as MD-11, a variety of improvements were carried out. The wingspan grew bigger and the >length increased. The biggest external change is the montage of winglets, which were added to reduce the fuel consumption. Pilots that fly both planes can tell whether it's the MD-11 or not by the digital cockpit and better performance. These are mostly thanks to the new engines.

Already back in 1976, the American aircraft manufacturer considered a massive improvement of their three-engined widebody. In that year, the Boeing 747SP was announced, a shortened derivative from the 747 with a more extensive range. Because McDonnell Douglas saw the sales of their long range-DC-10 drop, they looked at the possibility of installing larger fuel tanks on the DC-10. This version would be introduced as DC-10 global. But that idea didn't leave the drawing board, just as the design of a stretched DC-10-10 and -30.
The project that was first called DC-10 Super 50 was rechristenend to Super 60. It was clear a longer version, which offered seating capacity for 75 extra person than a comparable DC-10 had to be developed. Just like the DC-8 the plane would be offered in three types: the DC-10-61, which featured a 12 metre stretch was the model for domestic flights, the DC-10-62, which was 8 metres longer and met the need of an intercontinental airliner and the DC-10-63. This final version combined the longer fuselage of the -61 with the aerodynamic improvements found on the -62.
Then, disaster struck for the programme. In 1979, two severe crashes with DC-10's had taken place. American Airlines flight 191 lost its left engine due to maintenance errors and flight 901 of Air New Zealand hit a mountain. Due to the media attention, McDonnell Douglas decided to cancel further development of the tri-jet.

But the engineers weren't very good at doing nothing In 1981, the manufacturer leased a DC-10 from Continental Airlines to test the effect of winglets. From that experience, the MD-100 was created. The plane would be offered in two versions. The Series 10 was, compared to the DC-10 a little shorter, the Series 20 was made longer. Like the earlier studies, this project was abandoned, now due to poor sales of the existing DC-10.
One year later, things looked a lot better for the aircraft company. Because of that, it went on with the development of the improved tri-jet. In July 1985, the manufacturer agreed that the airliner, which was called MD-11 for the first time, could be offered to airlines. There were two versions: the length kept the same (nearly 7 metres longer than the DC-10) but the range and maximum take-off weight differed. The first version was able to fly 8.840 kilometres, the second type almost 13.000. When there were a number of customers, the engines were changed. New techniques made it possible to fly 13.900 kilometres non-stop.

On the 30^th of December 1986, the MD-11 was introduced. With 52 fixed orders and 40 more options, the future of the plane was guaranteed. It was a pity 3 customers dropped out in 1988, so 7 were left. In March of the same year, the production started. In October, the fuselage and wings were joined for the first times. Due to delays by late delivery of parts the first flight was postponed from March 1989 to the 10^th of January 1990. On December 7, 1990, the first delivery to Finnair occurred. The first commercial flight was made on December 20, 1990.
Straight opposite of these gratifying facts were some cancellations. The performance wasn't as high as promised, so a couple of airlines chose for another plane. In 1990, McDonnell Douglas and NASA, the American Aviation and Space Agency, started the development of a PIP, a Performance Improvement Package. The technicians looked closely to possible improvements on the aerodynamics and tried to think of ways how to save weight. When this upgrade was done in 1995, it was too late, actually.

The different sizes that were proposed didn't make it to mass production. However, there are a couple of models available.

McDonnell Douglas MD-11(P) (1986)

By far the most MD-11's (131) are this model. The plane is built for moving persons and is also known as MD-11P (P for Passenger) for that. This first type sold well to large airlines, under which American Airlines (19), Delta Air Lines (17), Swissair (16), JAL and KLM - Royal Dutch Airlines (both 10 planes). Of that, only the Koninklijke Luchtvaart Maatschappij is still using them, together with Finnair (7) and TAM Linhas Aéreas (3).

McDonnell Douglas MD-11C (1986)

The MD-11C, the combi, was only produced 5 times. The power of this type is in the interior with two parts: both cargo and passengers have enough space. There's also the possibility to use this plane as a complete passenger aircraft. All combi's were produced between 1991 and 1992 and have been delivered to Alitalia. The original customer converted them into full freighters in 2005 and 2006.

McDonnell Douglas MD-11CF (1991)

The MD-11CF is developed due to an order of Martinair. The type is easily convertible from passenger to cargo aircraft. Of the six planes that were built, four were delivered to launch customer Martinair. The other two are bought by World Airways, which converted them into a freighter for the last time in 2002.

McDonnell Douglas MD-11ER (1994)

In 1994, the MD-11ER was introduced. The plane exists because of a couple of improvements, the increased range being the most important. The ultimate borderline was moved to 13.400 kilometres. Between 1995 and 1997, the only 5 ER's were delivered. Three of them were sold to Garuda Indonesia, the other two to World Airways. Until now, there's one aircraft that was converted into a normal MD-11. The jet is currently operated by Finnair.

McDonnell Douglas MD-11F (1986)

The Freighter is the MD-11 that was manufactured for the longest period. It started in 1988 and ended in 2000. The deliveries took place between 1991 and 2001. Federal Express (22) and EVA Air (9) are the main users of this model.

After the take-over of McDonnell Douglas by Boeing in 1997, the last promised that the production of freighters would continue. One year later, the company announced not to write down new orders, though. The last two MD-11's were built in June and September of 2000. The were delivered to Lufthansa on the 21^st and 22^nd of February, 2001.
There was the idea of taking the tail-engine out and re-introducing the MD-11 as a jet with two engines: cheaper in use and maintenance. However, this idea wasn't realized.

Many MD-11's are still flying. The passengerversions are often replaced by Airbus A330's, A340's or Boeing 777's, but the freighters are used frequently. This is mostly (but not solely) caused by the fact that there is no real successor of the plane. The most jets fly with the paint scheme of UPS (United Parcel Service) on their skin. All 30 planes that are operated by that firm are second-hand machines that were converted into freighters. It's likely that a couple more are added in 2008. Also Federal Express has a lot of MD-11's (as well as they operated many MD-10's) with 58 planes it the fleet. Again, most of them (37) are second-hand. Lufthansa (19) is followed by EVA Air, a Chinese airline with 9 MD-11's in use. The Dutch Martinair has relatively much MD-11's as well. Of the 7 tri-jets, 4 were delivered straight from the production plant (the CF's), 2 brand new F's and 1 Freighter that was bought from Swissair and was converted.