Why reversing engines is dangerous for certain aircraft. How airplanes land: disasters and accidents What is a reverse on an airplane

A good brake is essential for a safe landing of an aircraft. Reducing the landing distance is possible when using a variety of devices, ranging from standard brakes to aerodynamic complex devices. The most common method of braking is aerodynamic. In this case, a sharp increase in the drag of the aircraft is applied. For aerodynamic braking, most aircraft have special brake flaps that extend during landing. For other types of aircraft, they are mounted differently:

On the lower or upper surface of the wing.

On the sides of the fuselage.

At the bottom of the fuselage.

The use of a braking parachute is much more pronounced. Such a device is thrown out on strong slings from a special container, which is located in the tail of the aircraft. The parachute quickly fills with incoming air and sharply slows down the vessel, which significantly reduces the length of the landing run. In some cases, such braking reduces up to 60% of the runway.

The braking force generated by a parachute is proportional to the square of the speed. For this reason, the parachute should be released immediately after landing. Thus, the efficiency of the process is increased. To release the parachute, the pilot, using a hydraulic or electric drive, opens the compartment in which the parachute pack is located. After that, the pilot chute is ejected, which pulls the canopy and lines of the main parachute. There are different systems of braking parachutes: cruciform, tape and with circular slots. It is very important that the dome has sufficient breathability. This provides the necessary stability and eliminates the possibility of rocking the aircraft. However, at the same time, the air permeability should not be too high, since the braking force may be greatly reduced.

As a rule, the parachute is attached to the aircraft through a shear pin. In the event that a large overload occurs, it is cut off, preventing the supply of very high voltages. Brake parachutes are under enormous stress and therefore wear out quickly. If a side wind blows, their use is difficult.

The operation of drag parachutes in domestic aviation began about 70 years ago. In 1937, braking parachutes were used for delivery to high latitudes by Soviet Arctic aviation. However, at that time their operation was calculated purely on military aircraft.

Almost all passenger and military aircraft have wheel brakes. The principle of operation is almost the same as car brakes. The only difficulty is that the brakes on the wheels of an aircraft must absorb a huge amount of energy during braking, especially when braking heavy types of aircraft with high landing speeds.

The speed of braking is directly proportional to the power of the brakes, the experience and skills of the pilot, the coefficient of friction of the pneumatics. The effectiveness depends on the ability of the wheel brakes to absorb and dissipate the heat generated during the braking process.

In the 1920s, spacer shoe brakes began to spread in aviation. Lined with an organic soft material, the brake pads were pressed against the inner surface of the mild steel cylinder drum. But the energy intensity of such brakes is insufficient even in relation to light aircraft. They were replaced by chamber brakes. They had cylindrical drums. The pads were replaced by plates of friction material located around the circumference on the surface of the annular rubber chamber.

During braking, liquid or air is supplied to the chamber under pressure. As a result, the plates were pressed against the inner surface of the drum. Thus, the entire circumference of the brake drum was used, ensuring uniform contact of the surfaces.

But chamber brakes are great for large wheels, and the operation of a chassis with multi-wheel bogies or small diameter wheels has led to the need for a new type of brake. Thus, the designers invented disc brakes.

With small sizes, such brakes were characterized by high energy consumption and could develop a strong braking force. They were great for forced cooling. Disc brakes are of many types and are still used in world aviation.

A multi-disc brake consists of several stationary thin discs that alternate with rotating discs. Between the discs in the disinhibited state there is a gap and a wheel. When braking, the discs compress, rub against each other and develop braking force. Even a small volume multi-disc brake is able to absorb a lot of kinetic energy. In addition, there are single disc brakes with fixed friction linings located in pairs on both sides of a strongly rotating disc. During braking, each pair is pressed against the disc by the piston of a separate hydraulic cylinder.

The original designs of these brakes used mild steel discs and have since been replaced by alloy discs that retain their hardness and wear resistance over a wide range of temperatures. Friction pairs for steel alloys are excellently bonded by the method of cast iron and bronze. The addition of various additives - ceramics, graphite, aluminum oxide and others - affects the physical and mechanical properties of the material. To reduce the mass of brakes, engineers and scientists are looking for new materials. Created wheel brakes with heat-treated curved materials. They are covered with reinforced carbon fibers. Each such brake is much lighter than usual and retains strength at high temperatures.

The new brakes eliminated vibration, creaking and even braking. These brakes have strong wear resistance. Modern wheel brakes absorb a lot of energy. For example, the multi-disc wheel brake of a Boeing 707 aircraft absorbs 6.15-106 kgf * m of kinetic energy. Due to the release of a large amount of heat, it often becomes necessary to install the protection of the wheel and tire body with special heat shields and use artificial cooling of the discs.

In some designs, the brakes are blown with a huge amount of air that is supplied from the engine compressor, in others, atomized water is supplied directly to the discs. There are also special circulation systems with heat exchangers. In the initial stage of the run, the wheel brakes are ineffective. At low speeds, aerodynamic brakes are used, which at higher speeds create more emphasis. Thus, wheel and aerodynamic brakes interact with each other.

Landing conditions differ among themselves depending on the condition of the runway (runway), weather and other things. Therefore, it is extremely important how skillful the pilot is in the ability to brake. As a result of many refinements of research, automatic brakes began to be installed on aircraft, which make it possible to achieve the value of the friction coefficient of pneumatic elements. The coefficient of friction, which is obtained by the operation of the automatic brake, can be twice as large in comparison with its value. Braking performance increases with increasing wheel load, which makes it important to reduce wing lift as quickly as possible after landing. The flaps are removed immediately.

Turboprop and piston aircraft have long used propeller thrust reversal braking. Before landing, the angle of installation of the blades changes. The screw is given a negative value, which subsequently results in a backward thrust. Thrust reversal on aircraft with turbojet engines is considered even more effective. After the engine turbine, the flow of gases is directed opposite to the original movement. A negative thrust is formed, which slows down the aircraft.

Thrust reversal allows the aircraft to decelerate not only during the run, but also directly in the air, before landing. In turn, this leads to an increase in the reduction of the landing distance. There are gas-dynamic and mechanical methods of flow deflection for thrust reverse. In the first version, the flow is deflected by a jet of compressed air, in the second, part of the gas flow is deflected by deflectors. When creating reversing devices, designers take care that hot gas flows do not melt the aircraft skin.

All of the above on-board braking means can greatly reduce the length of the landing run, but still it remains relatively large. A sharp decrease in the length of the run is possible during the operation of stationary devices installed at some airfields (mainly on aircraft carriers). Basically, such delay devices are represented by strong cables - arresters. They are stretched across the runway at a height of 10-15 cm above the deck of an aircraft carrier or runway. Through a system of blocks, the ends of the cables are connected to the pistons of the hydraulic power cylinders. During landing, the aircraft clings to the cable with an installed hook. The bulk of the kinetic energy of the aircraft is spent on moving the piston in the cylinder. After 20-30 m the aircraft stops.

Reverse (aviation)

The flaps of the engine reversing device are activated and redirect the jet stream against the movement of the aircraft.

Reverse- a device for directing part of an air or jet stream against the direction of aircraft movement and thus creating reverse thrust. In addition, reverse is the applied mode of operation of an aircraft engine, involving a reversing device.

Reverse is used mainly on the run, after landing, or for emergency braking during aborted takeoff. Less often - taxiing, for reversing the aircraft without the help of a towing vehicle. A small number of aircraft allow the inclusion of reverse in the air. Reversing is most widely used in commercial and transport aviation. A characteristic noise can often be heard when the aircraft runs along the runway after landing.

The reverse is used in conjunction with the main (wheel) braking system of the aircraft. Its use allows to reduce the load on the main braking system of the aircraft and reduce the braking distance, especially with a low friction coefficient of the wheels on the runway, as well as at the beginning of the run, when the residual lift of the wing reduces the weight on the wheels, reducing the effectiveness of the brakes. The contribution of reverse thrust to the total braking force can vary greatly for different aircraft models.

Jet engine reverse

Using the reverse to slow down the aircraft during landing.

The reverse is realized by deflecting part or all of the jet emanating from the engine using a variety of shutters. In different engines, the reversing device is implemented in different ways. Special shutters can block the jet created only by the external circuit of the turbojet engine (for example, on the A320), or the jet of both circuits (for example, on the Tu-154M).

Depending on the design features of the aircraft, both all engines and some of them can be equipped with reverse. For example, on the three-engine Tu-154, only the outermost engines are equipped with a reversing device.

Restrictions

The disadvantages of the reverse system include the troubles associated with its use at low speeds (approximately<140 км/ч). Реверсивная струя может поднимать в воздух с поверхности взлётно-посадочной полосы мусор (например, мелкие камни), который, при пробеге самолёта по ВПП на относительно небольшой скорости, может попасть в воздухозаборник двигателя и стать причиной его повреждения . При высокой скорости движения самолёта поднятый мусор помех не создает, поскольку не успевает подняться до высоты воздухозаборника к моменту его приближения.

Propeller engine reverse

Rotation of propeller blades.

The reverse of propeller-driven aircraft is implemented by turning the propeller blades (the angle of attack of the blades changes from positive to negative) with the direction of rotation unchanged. Thus, the screw begins to create reverse thrust. This type of reversing device can be used both on aircraft with a piston engine and on turboprop aircraft, incl. and single-engine. Reverse is often provided on seaplanes and amphibians, because provides significant comfort when taxiing on the water.

Story

The first use of reverse thrust on propeller-driven aircraft can be traced back to the 1930s. So, passenger planes Boeing 247 and Douglas DC-2 were equipped with a reverse.

Aircraft without a reverser

A number of aircraft do not need reverse. For example, due to the peculiarities of the mechanization of the wing and the extremely effective air brakes in the tail of the BAe 146-200, it is not necessary to reverse when landing. Accordingly, all four engines do not work in reverse mode. For the same reason, the Yak-42 aircraft does not need a reverse device.

Using reverse in the air

Some aircraft (both propeller and jet, military and civil) allow the possibility of in-flight thrust reverse, while its use depends on the specific type of aircraft. In some cases, the reverse is turned on immediately before touching the strip; in other cases, on a descent, which makes it possible to reduce the vertical speed by braking (when approaching on a steep glide path) or to avoid exceeding the permissible speeds when diving (the latter applies to military aircraft); to perform combat maneuvers; for a quick emergency descent.

So, in the ATR 72 turboprop airliner, reverse can be used in flight (when the pilot removes the safety seal); the Trident turbojet also allows reverse in the air for a rapid descent at vertical speeds of up to 3 km / min (although this possibility was rarely used in practice); for the same purpose, the reverse of two internal engines of the Concorde supersonic liner could be turned on (only at subsonic speed and at an altitude below 10 km). The C-17A military transport aircraft also allows the inclusion of a reverse of all four engines in the air for a quick descent (up to 4600 m / min). The Saab 37 Wiggen fighter also had the ability to reverse in flight to reduce landing distances. The single-engine turboprop aircraft Pilatus PC-6 can also use reverse in the air when approaching on a steep glide path on short landing areas.

For an example of using reverse thrust in the air (immediately before touching the runway), we can cite an excerpt from the flight manual for the Yak-40 aircraft:

at a height of 6–4 m, reduce the operating mode of the side engines to idle and start leveling the aircraft by giving the command: Reverse.

see also

Notes

Links

• (English) Checking the operation of the Learjet 60 reversing devices.
• (Russian) "Reverse educational program". Photographs of various models of reversing devices.
• (English) Landing IL-86 on a wet lane. Clouds of moisture well illustrate the work of the reverse. Panoramic view.
• (English) Landing Boeing-747 on a wet runway. Clouds of moisture well illustrate the work of the reverse with the overlap of the outer contour. View from the plane.
• (English) Landing Boeing-737. Illustration of the operation of the reverse with the overlap of both circuits. View from the plane.
• (English) A full stop of the McDonnell Douglas C-17 with reverse engaged caused debris to enter the engine and damage it.
• (English)
• (English) Illustration of the operation of the reverse on taxiing. The plane is moving backward.

If you want to read about aircraft engine thrust reverser, I recommend checking out a recent article on the subject. It was written on 03/30/13 and is located on this site in the same section under the title “Once again about thrust reverser ... A little more ... :-)”, that is. And this article (where you are now), in my opinion, no longer meets the exacting needs of both mine and my readers. However, it will remain on the site, so if you want, you can pay attention to it too ... Only for comparison :-) ...

The work of the reverse when landing A-321.

The problem of aircraft deceleration after landing on the run was insignificant, probably only at the dawn of aviation, when aircraft flew slower than modern cars and were much lighter than the latter :-). But in the future, this issue became more and more important, and for modern aviation with its speeds it is quite serious.

How can you slow down an airplane? Well, firstly, of course, with brakes mounted on a wheeled chassis. But the fact is that if the plane has a large mass and lands at a sufficiently high speed, then often these brakes are simply not enough. They are not able to absorb all the energy of the movement of a multi-ton colossus in a short period of time. In addition, if the contact (friction) conditions between the tires of the chassis wheels and the concrete strip are not very good (for example, if the strip is wet during rain), then braking will be even worse.

However, there are two more ways. The first one is drag parachute. The system is quite effective, but not always easy to use. Imagine what kind of parachute is needed to slow down, for example, a huge Boeing 747, and what kind of parachute service should be at a large airport, where planes land, one might say, in droves :-).

The work of the reverse (sash) on the Airbus A-319 of the company JeasyJet.

The second method is much more convenient in this regard. it thrust reverser aircraft engine. In principle, this is a fairly simple device that creates reverse thrust, that is, directed against the movement of the aircraft, and thereby slows it down.

Reverse device on turbojet engine. The hydraulic cylinders for controlling the reversible flaps are visible.

Reverse thrust can create propeller-driven aircraft with variable pitch (VISH). This is done by changing the angle of the propeller blades to a position where the propeller begins to "pull" back. And on jet engines, this is done by changing the direction of the outgoing jet stream using reverse devices, most often made in the form of flaps that redirect the jet stream. Since the loads there are multi-ton, these doors are controlled by a hydraulic system.

Reverse on a KLM Fokker F-100.

The main application of thrust reverser is braking during a run. But it can also be used for emergency braking if it is necessary to stop the takeoff. Less often and not on all aircraft, this mode can be used when taxiing at the airport for reversing, then there is no need for a towing vehicle. The Swedish fighter Saab-37 Viggen is very characteristic in this regard. His evolution can be seen in the video at the end of the article.

Fighter Saab 37 Viggen.

However, in fairness, it should be said that it is almost the only aircraft that so easily drives around in reverse :-). In general, reverse thrust on jet engines is rarely used on small aircraft (). It is mainly used on commercial and civil aviation liners and airplanes.

It is worth saying that some aircraft provide for the use of reverse thrust in flight (an example of this is the ATR-72 passenger aircraft). This is usually possible for an emergency descent. However, restrictions are imposed on such modes and they are practically not used in normal flight operation.

Aircraft ATR-72.

The aircraft has, however, with all its advantages and disadvantages. The first is the weight of the device itself. For aviation, weight plays a big role and often because of it (and also because of the dimensions) the reverse device is not used on military fighters. And the second is that the redirected jet stream, when it hits the runway and the surrounding soil, is capable of lifting dust and debris into the air, which can enter the engine and damage the compressor blades. Such a danger is more likely at low aircraft speeds (up to about 140 km / h), at high speeds, debris simply does not have time to reach the air intake. It's pretty hard to deal with this. The cleanliness of the runway (runway) and taxiways is generally an ongoing problem of airfields, and I will talk about it in one of the following articles.

Aircraft Yak-42

It is worth saying that there are aircraft that do not need jet thrust reversers. These are, for example, the Russian Yak-42 and the English BAe 146-200. Both have advanced wing mechanization, which significantly improves their takeoff and landing characteristics. The second aircraft is especially indicative in this regard. In addition to mechanization, it has tail air brakes (shields) that allow it to effectively dampen speed during descent and after landing on the run (together with the use of spoilers). There is no need to reverse, which makes this aircraft suitable for use at airports located within the city and therefore sensitive to noise, as well as having a steep landing pattern (for example, London City Airport).

Aircraft BAe 146-200. The open brake flaps in the tail are clearly visible.

However, there are still not so many such aircraft, but thrust reverser is already a fairly well-developed system, and without it, the work of airports is unthinkable today.

In conclusion, I suggest you watch videos in which the operation of the reverse mechanisms is clearly visible. It can be seen how the reversed jet lifts water from the concrete. And, of course, SAAB's "reverse" :-). Better to watch in full screen :-)..

Photos are clickable.

Yes, where I work now is a contractor. And not only Boeing, but also Airbus, Bombardier, ARZh-21, Augusta Westland, etc.

Fischer Advanced Composite Components. FACC for short.

Together with Goodrich, we are collaborating with Boeing on this project and may be collaborating on the A350.

Thanks to an excellent occasion in the form of rolling out a new Boeing 787 Dreamliner model and the informational support of our dad Nestor, a number of comrades just now in general and on the B-787 Dreamplane in particular. I understand that LJ can be read by completely different people with very different levels of awareness and areas of interest, so I will break the answer into three parts.
For those who are "in the know", Translating Sleeve is the rear part of the engine nacelle with reverse elements.
For beginners and those who are more interested in knowing more, I will try to describe it in a simpler way. If something is not clear, ask, and if it is written too naively, then do not judge strictly. Well, for those who do not need to talk about the plane, but just talk about the reverse, you can just read the final part of my opus.

What is a reverse?
The landing speed of modern liners is about 200-240 km / h, which is certainly much lower than cruising speed, but still quite a lot for multi-ton machines. At this speed, aerodynamic control rudders are still effective and ground-based traffic controls are still very ineffective. With a sharply applied brake at such a speed, the aircraft will not slow down, but simply “take off” - it will tear the tires of the landing gear wheels.

Translating Sleeve Reverse Thrust on Boeing 787 Dreamliner. Part 3

How does reverse work?
In the 60-70s. the reverse was most often designed as the back of the engine nacelle, in the form of two "buckets", simply blocking the path of the jet stream of the engine and directing it in the opposite direction. A similar reverse was used in the design of aircraft until the 70s (Fokker-100, B737-200, Tu-154 and An-72/74). An obvious plus is the simplicity of the design. Minus - the need to develop "temperature-loaded" structures, additional protection of adjacent elements (wing or fuselage skins).

Translating Sleeve Reverse Thrust on Boeing 787 Dreamliner. Part 4
How is reverse arranged?

The engine nacelle as a whole on modern liners consists of an air intake (Inlet Cowl), a fan fairing (Fan Cowl), and the rear of the engine nacelle, where the second engine circuit (Fan Duct) and the reverse (Reverse Thrust) are located. The latter, as well as the fan fairing, consists of two halves that can be moved apart for access to the engine during maintenance and repair work. The term Translating Sleeve in this case refers to the outer fairing of the second circuit, which includes the outer skin and the outer skin of the second circuit of the engine (Outer Cowl, Outer Duct).
S-17, Tu-334 and An-148 and many other aircraft, including the Dreamliner.

Directly Translating Sleeve aircraft Boeing 787 Dreamliner looks like this.

The field of aircraft engineering is of interest to many people, especially those who often fly airplanes. Knowledge will not only make you more erudite, but also relieve many fears, for example, the fear of flying. This article will talk about how the aircraft slows down during landing and about the methods of braking on different aircraft.

How planes slow down

Not only cars have brakes. Airplanes are also equipped with them, because when landing they can develop quite high speed, and the runway has a limit. Therefore, whatever one may say, one cannot do without a brake. There are several types of braking, and all of them are used on different types of aircraft. How do planes slow down when landing?

• Decreased engine power. The pilot simply slows down and the plane gradually comes to a halt without further assistance. But this method is only possible on a long runway.
• Changing the balancing position.
• Braking by increasing drag. This is usually achieved with the help of spoilers that extend after the pilot's command.
• Reverse braking. The aircraft engine turns on the reverse thrust, which is directed against the movement of the aircraft.
• With the help of brakes on the chassis. Like cars, they come in several types: shoe, disc and drum.
• A special parachute can also provide braking of the aircraft during landing.

Aircraft types

In aviation, two types of aircraft can be distinguished: civil and military. They are very different in design, so they have different braking systems. Also, the method of braking depends on the weight of the aircraft. Among military aircraft, fighters, interceptors, and bombers can be distinguished. They are small in weight and size, so they are most often slowed down using a braking parachute, which allows you to quickly stop the aircraft. Additionally, they use brakes on the chassis. Passenger liners usually use brakes on the chassis, as well as reverse engine braking. What it is?

What is reverse thrust

Engine thrust reverser is rarely used on small aircraft: it is mainly used on passenger liners. By itself, the reverse is needed to direct the air stream in the direction of or against the movement of the aircraft. The reverse thrust of the engine just serves for braking and for emergency descent. Most often, it is applied after the plane has landed and the wheels have touched the surface. Sometimes reverse is also used for reverse, but extremely rarely. But there are also How does a jet-powered aircraft work? If for a reverse in a conventional aircraft it is enough to close the damper so that the air goes in the other direction, then in jet engines there are special bucket doors that redirect the air flow.

Advantages and disadvantages of reverse

Aircraft engine thrust reverser has its pros and cons. The advantages include the fact that it allows you to slow down the aircraft at a time when the brakes on the landing gear are not yet working. With it, you can not only slow down, but also move in the opposite direction. With the help of a reverse, if necessary, you can quickly turn to the desired track by turning it on only on one of the engines. This is where all the pluses end. The efficiency of reverse motor reverse is only 30%. Therefore, other methods of braking are also often used on passenger aircraft. Together with them, there is a guarantee that the plane will definitely stop: if not using one, then using another device. Yes, and the weight of the device is too large, which is why it is used only on large liners that can boast of good carrying capacity. The disadvantages of the reverse also include its behavior at low aircraft speeds. When it drops to 140 or less km / h, there is a high probability of various debris being raised from the air, which can then get into the engines.

How passenger planes slow down

In passenger aviation, only one aircraft braking system is rarely used during landing. During the flight, many emergency situations can happen and in order to safely land the device, pilots usually have several options for braking. What can we say about passenger liners, where the responsibility increases many times. And the large weight of the aircraft simply does not allow braking using only one method. What methods are used in civil aviation?

1. Brakes mounted on a wheeled chassis. During landing, the aircraft is still at a sufficiently high speed that the brakes on the landing gear are never used as the only means of stopping. Yes, and you can use them only after the wheels have touched the runway, and in fact the speed of the aircraft must begin to reduce even before that. In addition, traction with the surface may deteriorate due to weather conditions: wet or icy surfaces.
2. Reversing the engine usually complements the first braking method. Only aircraft with a variable pitch propeller can create a reverse. The pilot simply changes the position of the propeller and begins to “pull” it in the opposite direction. On jet aircraft, reverse reverse is activated by changing the position of special dampers.
3. An auxiliary method of braking on passenger airliners is the use of special spoilers that extend during landing. They create drag, which also helps dampen the aircraft's speed.

The problem of braking in modern aviation is quite serious. After all, aircraft have been developing tremendous speeds for a long time, and their mass is most often very impressive. Therefore, the engineers had to try hard before they figured out how not only to land, but also to stop the Boeing or Liner.

emergency braking

In the modern world, it is not easy to do without international flights, which often take more than one hour. Despite all the progress of civilization, the number of people suffering from aerophobia is only growing. Statistics persuade us not to be afraid of flights, because the risk of getting into a fatal accident is much higher than that of a plane crash. But fears are rarely justified, so many continue to fly only after drinking a sedative. But fears can be reduced if you get to know better the structure of the aircraft and how everything in it is arranged in case of various unforeseen situations. If for some reason one or more braking systems of the aircraft failed, then there are additional emergency methods that help to stop the aircraft even in emergency situations.

For example, in the event of an emergency landing with damaged brakes, heated fuel oil is spilled on the runway, which helps to reduce speed. Small planes use a drag parachute, which is ejected after landing and allows you to stop it fairly quickly. Another way of braking: braking while still in the air by reducing engine thrust and increasing drag. As a rule, aircraft braking does not cause any problems during landing. And all the causes of serious air crashes lie mainly in the unfortunate combination of several circumstances.

Aircraft of different categories can differ quite a lot from each other in terms of technical characteristics and design. Therefore, it is not surprising that the braking systems on different models also differ. How is the aircraft and its braking system arranged? Most often, pilots brake using a hydraulic brake system. The weight of a light-engine aircraft rarely exceeds half a ton, so additional braking devices such as spoilers are rarely installed on them. Disc brakes are installed on the chassis itself, the design of which is identical to the design of the brakes on cars. When the brake is applied, the pads are pressed against the chassis and create a mechanical obstacle to its further rotation. The task of the pilot in this case is to organize such pressure so as not to damage the surface of the wheel, but at the same time reduce the speed of the aircraft. As a rule, this method of braking is quite enough to stop the aircraft. Some "maize" also have reverse braking, with which the pilot can also control the aircraft on the landing field. Small airfields rarely have towing vehicles, so this feature comes in handy.

Fighters

How do military aircraft slow down when landing? Fighters and other military aircraft belong to a very special category of aircraft. They are lightweight and capable of high speeds. In general, the braking method of fighters is not much different from other aircraft. They also use spoilers and brakes. Most aircraft have jet engines that have reverse thrust capability, but this feature is rarely used. If you turn it on during the flight, then the plane can simply be torn to pieces. And after the decline as a whole, it is enough to use only disc brakes and a spoiler. For example, the US F / a-18 fighter uses a spoiler spoiler as one of the braking systems, which rises above the aircraft body during descent. Also, in many models, the wings have many moving parts that can change their position and reduce the speed of the aircraft.

But there is one way of braking, which is used for the most part only on military aircraft. The parachute-braking unit is usually used during the approach to the airstrip, at a speed of 180 to 400 km/h. This allows you to dramatically increase air resistance, causing the aircraft to slow down. If the parachute takes off at the beginning of the strip, when the speed is still too high, then there is a risk of an accident, so it is used after applying other braking methods.

Water landing

Landing an aircraft on the water is considered one of the most favorable options for landing in an emergency. With competent actions, water softens the blow and helps prevent serious damage. In the history of aviation, repeated examples of water landings are known, as a result of which hundreds of people were saved. When landing on the water, the pilot usually performs the following actions:

• Flaps, landing gear and spoilers are removed, as they will only interfere with landing.
• Engines are switched to low speed.
• Overspeeding during landing is possible by 20 km/h, i.e. the speed of the aircraft is about 200 km/h when in contact with the surface.
• The nose of the aircraft should be slightly raised.
• When in contact with water, the aircraft must be positioned as level as possible so that the surface of contact with water is as large as possible.

Thus, when landing an aircraft on the water, the pilots do not apply either the brakes on the landing gear or the reverse. Braking is due to the natural resistance of the water.

Information for those who are afraid to fly

If you have read this article, but are still afraid of flying, then simple knowledge that lifts the veil of secrecy about flying on an airplane and its internal structure can help you.

• Each passenger aircraft has several jet engines. Thus, even if one of them fails, you are guaranteed to fly to the nearest airport.
• The flight of each vessel is controlled by the dispatch service, which monitors not only the weather, but also the route of the board.
• Most people are afraid of the turbulence zone. The so-called "air pockets" can cause considerable panic among passengers. But do not worry about the safety of the wings and other parts. They are made with the expectation of enormous loads. The wing of an aircraft can bend a lot, but not break.
• All systems have duplicate programs, so the risk of error is minimized. The same brake system has fallbacks, and this applies to all major parts of the aircraft.
• In most modern civilian airliners, the flight is carried out using an autopilot. If necessary, the control switches to manual mode, but you should not be afraid of the human factor - everything is automated to the limit.

Results

Landing an aircraft is the most difficult part of the flight, which implies a lot of responsibility. There is no single answer to the answer to how planes slow down when landing. The pilot needs to do a lot of actions, on which the softness of the landing will directly depend. Most often, to stop an aircraft, not one, but several aircraft braking systems are used, which are switched on sequentially one after another. First, the pilot reduces the engine speed, which allows you to reduce the speed by almost half. Therefore, the plane comes in for landing already at a speed of 200 km / h. Then the flaps are extended and brought to the stop. After that comes the turn of the brakes on the chassis, which serve as the main brake. If the runway is too short or some kind of emergency has occurred, then the engine reverser or parachute is connected (depending on the type of aircraft). The combination of these measures allows you to stop the aircraft even in adverse conditions.