Douglas DC-10

McDonnell Douglas DC-10 is a three-engine wide-body airliner developed by the company in the early 1970s. The DC-10 is the second serial wide-body passenger aircraft in the world (after the Boeing 747).

History

The history of the DC-10 airliners, like the history of the Boeing 747, began with the U.S. Air Force program to create a new large strategic transport (CX-Heavy Logistics System – CX-HLS), launched in 1963. The main bidders for the supply of military heavy military transport aircraft were Boeing, Lockheed, and Douglas. In the end, in 1965, the Lockheed project became the winner, and their plane became famous under the name C-5 Galaxy.

However, after the defeat, neither Boeing nor Douglas abandoned their projects. And if one of the major actors supporting Boeing was Pan American, which wanted a truly huge long-haul airliner, then several other operators doubted the prospects of such a large aircraft.

A technical side profile line drawing of a McDonnell Douglas DC-10-30 over a white background with and without the landing gear deployed

In 1966, another US flagship airline, American Airlines, presented its vision for the future of civil aviation. They also needed a roomy wide-body airliner capable of performing long-haul flights, however, this aircraft could be smaller than the Boeing 747 and, more importantly, it should be able to work with the available ground infrastructure.

In 1967, the Douglas Aircraft Company and McDonnell Aircraft Corporation merged to form McDonnell Douglas. The future aircraft was extremely important – it was supposed to be the first project of the combined corporation and its flagship. As a base, the Douglas developments under the CX-HLS program were adopted. In his initial research, Douglas worked on the issue of creating an airliner competing directly with the Boeing 747 – it was supposed to be a four-engine two-deck aircraft, accommodating up to 550 passengers. However, after the offer of American Airlines, it was decided to abandon such a scheme and create a smaller option: a wide-body aircraft with one passenger deck, accommodating up to 399 passengers.

At the same time, it was decided to use a group of three engines as a power plant. This scheme can be considered unusual for modern wide-body airliners, divided into four and twin-engine variants, but, given that the DC-10 was the second aircraft of this class, it was too early to talk about habitual. This choice was the result of a combination of several factors:

  • Firstly, turbofan engines were powerful enough and the four-engine design was already excessive in traction and unsuitable for the economy – the fuel consumption per passenger seat became larger than that of the Boeing 747.
  • Secondly, despite the high power, two engines were not enough to provide sufficient flight characteristics of the airliner of a given size and capacity.
  • Thirdly, the idea of ​​creating an airliner with a slightly lower capacity with two engines was considered as potentially promising (as a result, the Airbus A300 became such a liner), however, in the early 1970s there were still strict ETOPS restrictions for twin-engine liners, potentially severely limiting the possibility of long-haul flights in particular over the oceans.

In this niche, McDonnell Douglas faced fierce competition with Lockheed, who were actively developing their three-engine wide-body airliner L-1011 Tristar. By the end of the 1960s, competition between the two manufacturers became as fierce as possible.

However, in 1968, McDonnell Douglas secured an advantage over Lockheed by signing a large contract with a start-up customer, American Airlines. As it turned out, the Lockheed airliner was, potentially, more perfect, but its cost was higher, and some technological innovations could lead to delays in deliveries. Also, American Airlines played a good role in the competition of suppliers and achieved a reduction in the supply price of future DC-10s. But for McDonnell Douglas, it was a big win. Following an order for 25 airliners from AA, United Airlines ordered another 30 aircraft, and the options portfolio reached another 30 aircraft.

The work was very active – McDonnell Douglas wanted to overtake Lockheed. Finally, in August 1970, the DC-10 prototype made its first test flight, overtaking the competitor by several months (L-1011 took off in November). As part of test flights that lasted about a year, the DC-10 spent more than 1,500 hours in the air, and finally received a type certificate in July 1971. A month later, the first American Airlines livery-delivered livery flew from Los Angeles to Chicago.

Features

The DC-10 is a wide-body airliner with a low wing low sweep wing. The power plant is represented by three turbofan engines, two of which are suspended on pylons under the wing according to the classical scheme, and the third is located in the tail at the base of the vertical tail in a separate engine nacelle outside the fuselage.

As the base power plant, the latest at that time General Electric CF6 engines were used, created based on TF39 engines from the C-5 Galaxy transport. These engines were very breakthrough and, over time, began to be installed on many wide-body airliners Douglas, Boeing, and Airbus.

The avionics system was quite advanced for its time. The cockpit was designed for three crew members: two pilots and a flight engineer. Subsequently, part of the on-board systems and the cockpit underwent a deep modernization, unifying the DC-10 cockpit with the MD-11 cockpit. This made it possible to abandon the flight engineer and optimize the operation by operators who have both models in their parks, for example, FedEx.

The chassis of the early series (DC-10-10) was a tricycle. The main landing gear was equipped with four-wheel carts with a developed brake system. Later modifications (series -30 and -40), having a large mass, required a reinforced chassis and received additional support with a two-wheeled trolley located under the fuselage.

The use of optimal designs and the latest technologies provided a definite advantage of the DC-10 over the king of airliners. Although the Boeing 747 was superior to any other aircraft in terms of capacity, comfort, and range, it was very demanding on airports and services, which became a serious problem for the Boeing at the initial stage of operation. DC-10, is quite roomy and efficient, at the same time turned out to be much more loyal to ground infrastructure.

The passenger cabin of the liner had a width of 5.54 m (6.08 m for the Boeing 747) and had a maximum certified capacity of 380 passengers. However, such capacity was not achieved in practice. Basic configurations assumed 285 seats in a two-class layout according to the scheme 2 + 2 + 2 in business class from 2 + 5 + 2 in economy class. In terms of dimensions and layout, the DC-10 was extremely close to the L-1011, which made them direct competitors and motivated McDonnell Douglas to enter the market faster than Lockheed.

Aircraft located in the fleets of launch customers had superior salons, as they were of fashion interest for both operators and the manufacturer. American Airline’s liners accommodated 206 passengers in a two-class layout with seating areas and bars in the cabin, and the economy class had a 2 + 4 + 2 layout with the addition of small tables in the center row. Option United was also luxurious and accommodated 222 passengers.

Modifications

The first generation of liners received DC-10-10 indices. These aircraft had a maximum take-off mass of 195 tons (333 tons with a Boeing 747-100) and a range of 6116 km at full payload. These aircraft were created primarily for servicing lines within the United States. The aircraft received modifications -10CF, convertible into cargo, as well as modifications -15 with more powerful engines (21.1 ts vs. 18.2 ts for the base), increased to 7,000 km range, increased to 206 tons weight and the ability to work in conditions heat and highlands (series -15 was delivered to Mexico in the early 1980s).

To carry out transcontinental flights, a long-range version of the DC-10-30 was created. He received GE CF6-50 engines boosted to 23.1 ts, his maximum take-off mass increased to 259 tons, and a flight range of 10,000 km, which allowed the airliner to compete with the Boeing 747. The mass jumped by 53 tons required the integration of an additional fuselage landing gear. The DC-10-30 model became the most popular in the family (163 units) and turned out to be very popular in Europe: the starting customers of the model were Swissair and KLM, which received the first liners in 1972. Naturally, the model received cargo versions, as well as an ER version with boosted engines and an additional fuel tank, which allowed it to fly 10,620 km.

An alternative version of -30 was version DC-10-40. Initially, the aircraft was created under the DC-10-20 index and became the basis for long-range versions. However, unlike the -30 version, it was supposed to be powered by Pratt & Whitney JT9D engines. This decision meant that the DC-10 was now offered with two optional GE or PW engines, giving McDonnell Douglas an advantage over Lockheed, which had no alternatives. The version with JT9D engines allowed operators to optimize fleet maintenance since at that time the Boeing 747 was equipped with the same engines.

The aircraft was certified in 1972, however, the starting customer, Northwest Orient Airlines, asked to change the index from -20 to -40, as it positioned its new airliners as the newest and most advanced. Although versions -30 and -40, by and large, did not differ much from each other, outwardly they can be distinguished only by slightly different shapes of the tail nacelle (on the -40 model it is slightly convex near the air intake). In total, from 1973 to 1983, 42 -40 series liners were delivered to Northwest Orient Airlines and Japan Airlines.

Interestingly, different versions of the liners differed in power plants, wingspan, fuel capacity, and some other indicators, but McDonnell Douglas almost did not change the fuselage: its length and cabin capacity are the same in all versions.

One of the major customers for McDonnell Douglas became the US Air Force. The KC-10 Extender, designed for the military, was intended as an addition to the KC-135 Stratotanker tankers to support aviation over long distances from bases. A total of 60 aircraft were delivered.

McDonnell Douglas considered the idea of ​​creating a version of the DC-10-50, equipped with two Rolls-Royce RB211 engines, but the calculations showed insufficient thrust of two engines for an aircraft of this dimension and abandoned the idea.

Incidents

During the operation period (for 2015), DC-10 aircraft were involved in 55 accidents, 32 of which were serious accidents and catastrophes that led to the death of a total of 1261 people. The plane was the victim of terrorist attacks and hijackings, however, the plane did not avoid problems with childhood illnesses and design flaws, which several times turned out to be the causes of serious accidents. For example, the detection of a complex mechanism for locking the doors of the cargo compartment, leading to the opening in flight and depressurization. If in the incident near Winsor in 1972 a dozen people escaped with injuries, then near Paris in 1974 a similar opening of the door led to the crash of the liner and the death of 346 people.

Such cases, coupled with several other air crashes, led to the spread of the view that the DC-10 is an unsafe aircraft, which had an extremely negative impact on its success. Despite the rather high-reliability indicators in the subsequent period, he failed to restore his reputation in the community.

Retirement

Production of the DC-10 lasted less than 20 years. The first operator since 1971 was American Airlines. Deliveries were completed by transferring 446 aircraft to Nigeria Airways in 1988. Ironically, in the case of this aircraft, the company’s marketers almost accurately guessed – in 1971 it was assumed that 438 aircraft would be delivered. Nevertheless, the reputational costs after accidents and disasters did not allow the liner to quickly capture the market, and the niche of the three-engine wide-body airliners was subjected to pressure from the Boeing 747 from above and, unexpectedly successful Airbus A300 and A310 from below. Immediately after the completion of the production of DC-10, McDonnell Douglas began active work on his heir. After 2 years, in 1990 the liner MD-11 made its first flight.

For 2015, 56 aircraft are in commercial operation, most of which in cargo versions fly in the FedEx Express fleet. The flights of passenger liners were completed in the USA in 2007 and the rest of the world in 2014. Only cargo modifications, air tankers, and several special aircraft, mainly military ones, remain in operation.

Specifications

  • Type: Mainline Passenger Aircraft
  • Maximum number of passengers: 255 (3 classes)
  • 285 (2 classes)
  • 380 (maximum)
  • Practical ceiling: 12 802 m
  • Cruising speed: 908 km / h (982 km / h maximum)
  • Length: 51.97m
  • Height: 17.7 m
ModificationDC-10-10DC-10-15DC-10-30DC-10-40
PowerplantGE CF6-6DGE CF6-50C2FGE CF6-50CPW JT9D-59A
Engine thrust3 X 18.15 tf3 X 21.1 tf3 X 23.14 tf3 X 24 tf
Range6,616 km7,000 km10,622 km (ER)9,254 km
Maximum take-off weight195 t 206 t 259 t 251 t
Wingspan47,34 m47,34 m50,4 m 50,4 m
Graduated from Embry-Riddle Aviation University with a master's degree in aviation science. He began his career as an aviation researcher in local periodicals. Has a pilot license. Now are the author and developer of the Plane Worlds.