Military Review

The concept of combining aircraft with the train: Clip-Air

The Clip-Air aircraft project was created at the Federal Polytechnic School in Lausanne, starting with 2009. The aircraft model with a wingspan of 1,2 meters will be shown to the public for the first time at the anniversary air show at Le Bourget, which began today, June 17, 2013. In this case, the plane looks more than unusual. Clip-Air consists of a carrying part, the so-called “flying wing” with engines, fuel tanks, chassis and cockpit and transport capsules attached to it, which can accommodate both cargo and passengers. In total, under the wing of the aircraft can be placed up to 3-x "capsules" approximately 30 meters long and weighing up to 30 tons each, with a total capacity of up to 150 passengers.

This concept could be born only in Europe. Though aviation transport here is quite well developed, at short distances for convenience and sometimes speed it can easily be inferior to railway transport: after all, you must first check in at the airport, get to the airport by something, and leave the arrival airport in the same way . All this, as well as possible delays in getting baggage, can eat a lot of time, so if you make a trip closer than 1000 kilometers, using high-speed railway transport looks like a more convenient alternative.

Those people who follow the development of modern transport, most likely, saw various hybrids that combine a plane and a helicopter or a car and a motorcycle. But the Swiss engineers from Lausanne decided to go even further and combined two, at first glance, completely opposite ways of transporting goods and passengers - they tried to combine the plane and the train. The concept of a completely new vehicle, called the Clip-Air, is a very large aircraft that has not one, but three capsule bodies at once. Each of these capsules can be filled with passengers or cargo separately, and then attached to the general basis of the aircraft - the “flying wing”.

The concept of combining aircraft with the train: Clip-Air

The creators of Clip-Air are now comparing their invention with a train that can cruise not across ordinary rails, but across the sky, while capsules in this type of transport will play the function of railroad cars. In the concept proposed by the Swiss inventors, it is remarkable that these capsules can also play the role of ordinary rail cars. Capsules can be filled with passengers at railway stations, and not at airports. This innovation, as well as the significantly increased capacity of the airliner, will make it possible to make flights with Clip-Air much cheaper than even on the most economical models of modern aircraft.

Arriving at the destination airport, Clip-Air unhooks the saloon car from itself, after which they are transported by rail to the usual railway stations, without making transfers, checking baggage and other horrors of standard airports. Concept developers recognize that their project is currently quite futuristic, and in order to embody it in metal and put it on the wing, they will have to overcome a number of complex technical barriers, but at the same time the Swiss believe in the future of their proposed concept, which runs counter to canons of modern aircraft.

There is nothing strange in this, the concept has a number of advantages. Firstly, the proposed concept is quite convenient. Passengers of such an aircraft will be able to get into wagons at railway stations, even in relatively small settlements, and then arrive by rail at major airports, from where (without numerous checks and tedious transfers) they can continue the journey in the same wagons, but by air. In addition to the struggle for the convenience and speed of movement of passengers and goods, this project offers significant benefits in terms of cost.

One “flying wing” will be able to work at once for several different airlines or their consortium, taking on flight “capsules” and not standing idle while waiting. This vehicle, as a matter of fact, can transport cargoes and passengers of 3's companies directly under one wing. Which, which is also quite important, will be able to rent the plane, rather than acquire their own aircraft, in this case, individual capsules.

Secondly, in a similar plane-car, instead of people, you can place a very large gas tank. The latter is quite important: aircraft built according to the classical scheme have too small internal volume in order to transport prospective gas fuel through the air. For example, the Tu-155 still in the 1988 year could fly on liquid hydrogen, while in theory nothing could prevent the use of airliners on liquefied methane, which today has become a cheaper type of fuel.

As practice has shown, the tank for liquefied gas does not matter which one, it turned out to be quite difficult (almost impossible) to place in the wings of an airplane - ordinary cars have just too little free space. At the same time, placing the tank in the fuselage almost in 2 times reduced the passenger capacity of the experimental aircraft Tu-155. However, the layout of the flying wing is quite suitable for these purposes, since most of the volume when carrying out flights on liquid fuel still remains unclaimed. In theory, even the most ordinary liquefied methane nowadays costs several times cheaper than fuel derived from oil, and the existence and production of shale natural gas suggests that in the foreseeable future the situation is unlikely to change for any reason.

Thirdly, according to Swiss developers, Clip-Air will be able to solve an important enough task that was set by ACARE (European Advisory Council for Aeronautical Research): to reduce the amount of CO2020 emissions by 2 right away by 50% during air flights ( in terms of the length of the route and the number of passengers). A three-engined plane-wagon Clip-Air will be able to carry just the same number of passengers as an 1 twin-engine A3 aircraft in 320 flight. When flying over a distance of more than 4 thousands of kilometers, fuel savings (and emission reductions) will be very significant, lower than those of three twin-engined Airbus. In addition, the aircraft makers are considering the possibility of using biofuels and liquid hydrogen instead of traditional types of aviation fuel.

With all the economic and environmental advantages of the Swiss project, there are also enough difficulties and they are quite obvious. Aerodynamics 3-x capsules, fixed under the general flying wing, will be worse than the standard single-bodied aircraft, designed according to the classic layout. Of course, this is amenable to optimization, but, according to the creators of this project, optimization is still far enough from the end.

Serious enough is the problem of the landing gear. Ordinary projects of a flying wing (without the use of suspended car parlors) often involve the use of an air cushion. Although the idea, which was implemented on Pe-2 and UT-2 aircraft, demonstrated the ability of such aircraft to land even on water or in the tundra, classical aircraft have too little space that would be convenient to accommodate such a chassis. In theory, the flying wing of such areas is much more, while the overpressure in an air cushion in this particular case may be insignificant. However, Clip-Air will not be so easy - the use of an air cushion is hampered by suspended “fuselages” with people and cargo.

Therefore, the Swiss design chassis mostly conventional scheme (16 wheels), which will be suspended in special nacelles, located on 2-x well-developed pylons, which are located between the exterior passenger compartments and side engines. It is quite obvious that the resistance of such a chassis will be comparable to the “bast shoes” of the famous Ju-87 and is unlikely to have a positive effect on fuel consumption, although it will not override all the economic benefits of Clip-Air.

The general strength of the proposed design also raises questions: the fastenings of passenger and freight-wagons must have a very significant margin of safety; It will also require a significant strengthening of the flying wing itself in places of similar interfaces. Of course, the total weight of the structure will depend on the specific materials and decisions that the developers choose, but today it is clear that creating an equally strong structure will require greater sacrifices than the aircraft of the classical scheme or the classic flying wing. Finally, for a good, confident control of such a complex flying wing, effective electronics assistance will be needed: it will be quite difficult for a human pilot to maintain Clip-Air in the air and to maintain its stability. However, this obstacle in the past few decades has already learned to overcome.

In general, it is still too early to talk about what exactly will come out of this project. Too many things are still to be created and refined. So far only the 1,2-meter layout, which is presented in Le Bourget. However, the ideas of multimodality and modularity, which are already incorporated in this project, are potentially quite interesting and with a decent design implementation they will be able to make a real revolution in modern air transport.

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  2. Constantine
    Constantine 18 June 2013 09: 57
    The economic model is weak, in my opinion, in the following places:
    1. Not many companies, such as Virgin, can really afford to combine rail and air transportation, but this will require new infrastructure and new rolling stock. For example, at Heathrow Airport this may not work due to the high workload of the airport, proximity to the city, and accordingly a small free space for maneuvers. Construction of a railway terminal with loading / unloading systems + railway line to this terminal, etc. require space. In addition, it is necessary to synchronize systems at the railway and at the airport. In addition, a baggage check will be applied, in this case, when boarding the train. This is a general safety policy for passenger air travel.

    2. In your article, efficiency was compared with 3 Airbus A-320s, but it would be more logical to compare an airplane with 450 passengers, not with them, but with an A-380 comparable in parameters, which can take, on average, 1000 passengers and fly for 15200 km. If you look at the engines and consider the savings as they thought here, then 6 A-320 engines against 3 Clip-Air engines with a similar load are clearly inferior to 4 engines against 3, but with a load of more than 2 times longer and longer flight ranges. In general, efficiency should be considered as units. fuel per 1 passenger-kilometer.

    3. External containers on planes were installed on Myasishchev's planes, so the idea itself is most likely borrowed and reworked, but in no way is a breakthrough "know-how".

    In general, thanks for the review. It is interesting to read about what is in development and what are the general trends.
    1. Constantine
      Constantine 18 June 2013 11: 13
      And I’ll add that airlines will not rent this plane because railway suspension modules, which has nothing to do with airlines, but will add problems to railway workers due to additional checks. In addition, without the participation of airlines, the entire infrastructure, the assembly plant of aircraft and rolling stock, etc. etc. falls on the shoulders of developers and investors, which will fly off in a very large amount. An airline, even a classic one, is a very complex mechanism that requires huge upfront costs. Someone even said that in order to create a 10 million airline, you need to invest 100 wassat In this case, all 300, or even more, will have to be invested.
      1. Papakiko
        Papakiko 18 June 2013 17: 18
        Quote: Constantine
        10 million, you need to invest 100 in it. In this case, you will have to invest all 300, or even more.

        Though invest in.

        the most peppy The idea for transcontinental (and not only) flights was still discussed in the Soviet country, namely:At high altitudes (up to 20 km), high-speed high-speed aeromodules fly and take-off and take-off (dock-undock) take-off and landing modules.

        The Airbus philosophy with the A-380 and its subsequent development are built on this scheme.

        And the proposed scheme is suitable only for mega-dimensions.
        But this is a separate story already with other physical principles and not on jet thrust.
        1. Constantine
          Constantine 19 June 2013 00: 04
          I suspect that the Europeans simply needed to declare that they, in terms of technology, still "know how". not much is known about the breakthroughs of European scientists, against the general background. The project is strange in itself. In terms of efficiency in air transportation, our "Fregat" will be an order of magnitude steeper and cheaper to sell than such a "miracle".
    2. AVV
      AVV 3 September 2013 23: 35
      The project is quite crude, and also not economically justified !!!
  3. Aryan
    Aryan 18 June 2013 09: 59
    and the driver of the locomotive only needs "back and forth"
    and the driver of the plane is also "up-down-left-right"
    but without "back" wassat
    But seriously on the subject, from my own experience in one of Moscow's Eroportoff, I realized how well
    that you can serve yourself one place
    so in my opinion, let the passengers move their rolls once more when transplanting
    less fat will be wassat
  4. Gato
    Gato 18 June 2013 10: 10
    Back to the Future laughing
  5. Gato
    Gato 18 June 2013 10: 15
    Or this:
  6. biglow
    biglow 18 June 2013 11: 44
    everything is too complicated, usually simpler constructions survive. Our engineers, when they get to this, will probably come up with something more reasonable
  7. Igar
    Igar 18 June 2013 12: 03
    One question: why is this even necessary?
    1. shurup
      shurup 18 June 2013 23: 46
      To hang three thirty-ton bombs or 150 paratroopers.
  8. Taoist
    Taoist 18 June 2013 12: 06
    Not a new idea, to put it mildly. Back in the 70s in the journal "technology-youth" there was a large article describing the transport system of the future in the image of "universal containers" (freight and passenger) which in automatic mode (using radio tags) the system unloads from train to plane, to ship, to trailer and etc. In principle, a completely realizable task ... and there is no need to "fence in the garden" by inventing such flying monsters. The problem is different. if such a system is more or less clear with loads (and by and large works), then with the passenger module it will be necessary to solve the problem of providing life support in an almost "closed cycle". Well, the question is to agree on a single international standard for such modules. How much the "game of dressing" will cost is an acute question. But with the modern development of computer control and dispatching systems, such a system has no technical contraindications.
  9. Taz
    Taz 18 June 2013 16: 04
    Everything is beautiful on paper, but as life experience shows, theory and reality are "two big differences."
  10. Evgeny_Lev
    Evgeny_Lev 18 June 2013 17: 26
    Purely from a psychological point of view, I, as a passenger, would be very uncomfortable to realize that I was in some kind of crap that could come off the mounts and fly down))

    I was thinking about solving the problem of traffic jams in Moscow (for some, wealthy segments of the population). So there was the idea of ​​constructing a helicopter-type aircraft that would cruise along certain routes and from certain places, carrying the entire vehicle under it. Those. the client drives into the loading place, his car is picked up by a special device under the device, after which the car with the client flies to the "unloading" point along the specified route, where without leaving the car, the client calmly continues to move on public roads.

    I think my project will be more real.
  11. luiswoo
    luiswoo 18 June 2013 18: 03
    Trifle pot-bellied.

    Up to 1200 people in the “passenger” version (also a suspended gondola).
    I do not understand the tsimesa gondola-undercar. You will need a train-telka, as I understand it is special. Her logistics for the railway will be “fun" - because load it other than the same gondola, it seems, there will be nothing more.
  12. Grif
    Grif 18 June 2013 18: 13
    Of course, more realistic. In the "Diamond Hand saw smile But seriously, the idea of ​​an air mega container ship is very interesting. Most likely, something like this will first be used on ekranoplans.
  13. brosai_kurit
    brosai_kurit 19 June 2013 21: 40
    I remember a bearded joke:

    "Now ladies and gentlemen, please buckle up, as with all this crap we're still trying to take off ..."
  14. Volodya Sibiryak
    Volodya Sibiryak 21 July 2013 00: 32
    Crazy idea.