General

Aircraft with vertical take-off. How do they work and why are they needed

You probably saw in a movie documentarya chronicle or technical video of how the plane begins to buzz violently, dust and other debris starts to fly from under it, after which it rises slightly above the ground. It begins to rise higher and higher, when at a height of a couple of tens of meters it gradually begins to “move off”, picks up speed and flies away like a regular plane. We will analyze how this happens, what are the advantages and disadvantages of such machines. Of course, we will not forget about their history and the most interesting representatives.

See Harrier demonstrates how it can hang in one place

Content

  • 1 What is VTOL?
  • 2 Types of vertical take-off aircraft
  • 3 Benefits of vertical take-off aircraft
  • 4 Disadvantages of vertical take-off aircraft
  • 5 History of VTOL
  • 6 Russian and Soviet aircraft with vertical take-off
  • 7 VTOL Prospects

What is VTOL?

First of all, it is worthwhile to understand thatthis is generally a vertical take-off airplane. In fact, such a term is more popular than technical. Even logically, if the plane took off vertically, then it should be able to land vertically. Hence the full name - Aircraft with Vertical Takeoff and Landing. It is abbreviated as VTOL. In foreign texts, there is an abbreviation VTOL (translated from English: Vertical Take-Off and Landing). At the same time, vertical take-off and landing does not exclude the possibility of a normal run along the strip. There were rare exceptions in history, but they all remained in projects of the past.

One may ask why the helicopter is not calledvertical take-off / landing aircraft? The fundamental difference is that in an airplane the lifting force during the main movement is created due to the air flow rushing onto the wing. In the case of a helicopter, the lifting force is achieved due to the work of the rotating propeller. If he stops, perhaps the helicopter will even be able to make a relatively soft landing in autorotation mode, but it will not be able to plan. In the case of aircraft, there is even a separate direction of aircraft without engines. They are called gliders, fly into the air with the help of a towing aircraft and can spend hours planning over the area like a paper airplane. In the event of engine failure in a helicopter, the only road will be down, and the plane will be able to fly and land for some time. Such cases have been more than once.

A clear demonstration of the principle of creating wing lift

Types of vertical take-off aircraft

As we have agreed above, VTOL are, inFirst of all, by air. This means that they are heavier than air and, for example, a balloon is not a VTOL aircraft. Therefore, this type of aircraft should create traction for itself. By the method of creating traction, they are divided into two main types.

The first includes aircraft such ase.g. Yak-38, McDonnell Douglas AV-8 Harrier II and Lockheed Martin F-35 Lightning II. They are equipped with lift-propulsion engines and a different number of lift engines. All engines use vertical jet thrust for takeoff. In simple terms, a jet of air from a jet engine.

Lockheed Martin F-35 Lightning II - fifth generation fighter with vertical take-off / landing

Another type of VTOL aircraft is called a “convertiplane” andcreates thrust for takeoff due to propellers. An example is the Bell V-22 Osprey, well known to us from the Half-Life game and films about special forces. Outwardly, it looks more like a cargo helicopter, but the main flight is carried out just like an airplane. After takeoff, its engines deviate and create an already horizontal thrust.

The same convertiplane Bell V-22 Osprey. In flight, he turned the engines forward and flew like a turbo-propeller aircraft.

The advantages of vertical take-off aircraft

The main advantage of aircraft with verticaltakeoff and landing is their increased maneuverability. An ordinary airplane cannot hang in the air. Thanks to the possibility of hovering, this type of aircraft opens up new possibilities for reconnaissance.

The second, but probably more important plus will bethe ability to take off and land on the site, which does not greatly exceed the dimensions of the aircraft itself. Such a runway does not need a runway. This is especially true when basing on small aerodromes and aircraft carriers. Perhaps these are all advantages that can be called at least a little significant. We turn to the disadvantages.

Disadvantages of vertical take-off aircraft

The main disadvantage of the VTOL will be that they are verydifficult to manage. Pilots must be real aces and must have the skills to control these very machines. Managing thrust changes from vertical to horizontal requires a very high level of training. Especially when it comes to landing on an aircraft carrier or maneuvering in high winds.

Only a real ace can fly such a plane during landing!

The biggest difficulties are when landing. When taking off, you need to raise the plane and begin to gain speed, and when landing, you need to calculate the approach so that the speed drops when approaching the landing site.

In addition, the danger during take-off andengines. If one of the engines fails in a normal flight, the plane can fly on the second and even just plan. If the vertical take-off / landing engine fails, a catastrophe is inevitable. They have happened more than once with both production cars and prototypes.

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Another disadvantage will be high fuel consumption forvertical take-off / landing. Engines operate in extreme mode to raise the aircraft with full armament. As a result, we get a shorter flight distance.

If take-off and landing on the site, barelyexceeding the dimensions of the aircraft are a definite plus, then the requirements for this site will definitely be a minus. The gas stream is very strong and hot. Tearing off a couple of tens of tons from the ground, it is capable of literally destroying asphalt under the plane. It turns out that the advantage of using “in the field” is offset by the requirement to make normal coverage of the site. By the way, such planes will not be able to take off in a real field; dust can disable engines.

History of VTOL

In the fifties of the last century, industrywas able to achieve such a level of development of turboprop and turbojet engines that one could think about aircraft with vertical take-off / landing.

Good question: Why do birds collide with planes?

This was especially true in the wake of the transition fromfighters that could take off and land on unpaved strips, to modern supersonic vehicles that needed a paved strip. Such a strip might not be near the place of conflict and hostilities. Of course, it was possible to build such strips, but the enemy could easily disable them. In this case, all aircraft at the base would become useless toys. By the way, it is largely because of military bases with the runway that influential countries make allies in different parts of the world. It is always nice when someone provides an airfield to base your planes on.

The listed difficulties forced the militarybelieve in the promise of new type of aircraft projects. First of all, this interest was precisely on the part of the military. For civil aviation, it was expensive and not very necessary. Therefore, the prototypes either did not enter the series, or even remained only on paper. The most famous of them can be called Hawker Siddeley HS-141.

This could look like a passenger VTOL Hawker Siddeley HS-141

Naturally, dozens of prototypes were created,most of which were seen by just a few people. They crashed during the first flight, after which changes were made to the design and the aircraft changed beyond recognition.

In mid-1961, the NATO Technical Commissionannounced the requirements for a single fighter-bomber with vertical take-off / landing. This pushed the industry to create supersonic VTOL aircraft. According to forecasts, in the 60-70s, about 5,000 new aircraft were to be delivered to the troops of the countries belonging to the Alliance.

How easy it is to guess for such a tidbitliterally everything decided to fight a piece of a military pie. Among the companies involved in the design of VTOL aircraft were such monsters as Messerschmitt, Lockheed, Dassault, Rolls-Royce and even the Italian Fiat.

The main problem of producing a single aircraftfor all NATO countries, it was that companies designed fundamentally different types of aircraft. Each country had its own vision of what VTOL should be like - no one wanted to make concessions and agree to another's monopoly. This greatly inhibited the design of the general aircraft, and the companies continued to design their own aircraft, which were sometimes very bizarre.

The prototype of the Ryan X-13 Vertijet. The platform was understood, after which the plane took off without difficulty.

Engineers even tried to get to the point.non-standard and tried to implement a project called the Ryan X-13 Vertijet. The essence of the aircraft was that it was suspended vertically before launch. After that, the engines at maximum thrust were supposed to lift the plane into the air. When a height of a couple of meters was gained, he moved away from the cable and flew vertically upwards, like a rocket. For stabilization at the wingtips, gas-jet rudders were located. For the main thrust and control, including during take-off, an engine with a deflected thrust vector was used.

With the take-off, everything is clear, but the landing wasa real work of art. The aircraft did not even have a landing gear for a backup. The pilot had to put the aircraft on its tail again, after which it was brought to the cable and, having thrown off the thrust, hang the aircraft on it with a special hook in the bow. Since the view was very poor, the land operator helped in landing. Doubtful scheme ... Only two such aircraft were created, and test flights lasted less than a year. The ideas were realized quickly enough. Fortunately, both aircraft survived and are in museums in the United States. There were screw analogs of the Ryan X-13 Vertijet, but nothing came of them at all.

The most successful was the multi-purpose projectBritish Aerospace Sea Harrier. You could see him in the movie True Truth. The hero of Arnold Schwarzenegger flew on it. Needless to say, without preparation he could not fly on it?

Shot from the film "True Lies." Arnold Schwarzenegger's hero at the helm of the British See Harrier

The first flight of this aircraft took place on August 201978, and the operation was completed only in May 2016. A total of 111 aircraft were produced in three versions. This is not much. For example, we can say that the F-16 Fighting Falcon multipurpose fighter, the first flight of which took place in 1974, released more than 4,600 units and continues to produce them.

“Harriers” were released only 111 pieces. Even the Yak-38 came out in a large circulation.

Now in the vertical versiontakeoff / landing is released fifth-generation fighter F-35 Lightning II. So far, relatively few have been produced, but a big bet is being made on it in the US Air Force and other NATO countries.

Russian and Soviet aircraft with vertical take-off

There was a VTOL program in the Soviet Union. Basically, she was engaged in the design bureau of Yakovlev. Development has been underway since 1960, and the first model was the Yak-36. He did not look very pretty, but on the whole he coped with his tasks. These tasks were research, and for them only 4 aircraft were created. They could not even raise the slightest serious weight of weapons - during a demonstration flight over Domodedovo in 1967, models were used.

The Yak-36 nose bar was by no means an idle decoration. It had a stabilization engine nozzle.

The plane became really important for the countryYak-38, which at the development stage was called Yak-36M. He was deprived of most of the problems of the previous “test” generation and for 27 years (1977-2004) became the main Soviet and Russian VTOL fleet. He was to be replaced by the Yak-141, but in 2004 the program was curtailed.

The handsome Yak-141, who never went into the series

More serious developments and mass modelsVTOL was not in our country. This is due to the low prospects of such devices and the financial difficulties encountered by design bureaus in the nineties of the last century.

The Yak-38 looked much better than its predecessor. Its functionality was also higher.

VTOL Prospects

Nowadays, vertical take-off aircraft do notas relevant as before. This was made possible thanks to more advanced air defense systems, which can protect the runways from destruction by the enemy. In addition, multifunctionality and low radar visibility of aircraft have now come to the fore.

VTOL cannot provide for such needs, yesthey also have high fuel consumption, greater weight and low efficiency of distribution of weapons. Such aircraft, of course, will not hurt, and many companies do not want to completely abandon plans for them. The time for such aircraft has not yet arrived, or almost passed. We will soon learn that from this we must “emphasize”.