How an airplane flies. Aircraft wing mechanization: description, principle of operation and design Slotted ailerons

It consists of a whole set of movable elements that allow adjustment and control of the flight of the device. The complete set of wing elements consists of flaps, spoilers, slats, spoilers and flaperons.

Flaps are profiled deflectable surfaces that are located symmetrically to the trailing edge of each wing. When retracted, they act as an extension of the wing. When released, they move away from the main part of the wing to form a gap.

They significantly improve the load-bearing characteristics of the wing when lifting off from the runway, as well as when the airliner is climbing and landing. They provide excellent lift and control of the vehicle at fairly low flight speeds. Throughout the history of aircraft manufacturing, many models and modifications of this part have been developed and implemented.

Flaps are an integral part of the wing. When they are released, the curvature of the wing profile increases significantly. Accordingly, the load-bearing capacity of the aircraft's wings increases. This ability allows aircraft to move at low speeds without stalling. The operation of the flaps allows you to significantly reduce the speed of landing and takeoff without danger to the aircraft.

Due to the extension of the flaps, aerodynamic drag increases. This is very convenient when landing, as they create more drag, which allows you to reduce your flight speed. During takeoff, such drag is a little inappropriate and takes away some of the engines' thrust. Accordingly, when landing, the flaps are fully extended, and during takeoff, at a small angle, in order to facilitate the operation of the power plant.

Due to the additional longitudinal moment of flight, overbalance occurs. This, of course, complicates the work of pilots in controlling and maintaining the normal attitude of the aircraft. In modern aviation, most aircraft are equipped with slotted flaps, which can consist of several sections; accordingly, they form several slits. The presence of gaps between the flap sections allows high-pressure air on top of the wing to flow into the low-pressure area below the wing.

The structure of the flaps ensures that the air stream flows tangentially relative to the top of the surface. The cross-section of the slot narrows towards the edges, this allows the flow rate to increase. Having passed the flap slots, the jet with high energy levels interacts with the layer of air under the wing, thereby eliminating the occurrence of turbulence. The flaps can be operated at the pilot's command or in automatic mode. Cleaning and extension of elements occurs due to electric, pneumatic or hydraulic drives. The first aircraft in our country on which flaps were installed was manufactured back in the 20s of the last century; it was an R-5 type aircraft. These wing elements began to be used more widely in the 30s, namely with the advent of machines with a monoplane body.

Main types of flaps

Rotary or simple flap. The most elementary in its design, it allows you to increase the lifting force of the vehicle by changing the curvature of the wing profile. This design allows you to increase air pressure from below the wing. Of course, this type is significantly inferior in efficiency to the panel type.

Shield type flaps. They can be retractable or simple. As for simple flaps, they are represented by a controllable surface that is in the retracted position, while they fit tightly to the bottom of the wing. By deviating, they create a rarefied pressure zone on top of the wing. Accordingly, the upper boundary layer flows down. Pressure increases from below, which creates additional lift. All this contributes to lift-off and climb at much lower speeds. Speaking about retractable shield flaps, it is worth noting that, in addition to deflection, they have the ability to extend backwards. This in turn increases their efficiency. This design allows you to increase lifting force by 60%. They are still used today on light aircraft.

Slotted flap type. They get their name due to the formation of a gap when they are deflected. A flow of air passes through it, which is directed with great force into the low pressure zone formed under the wing of the aircraft. At the same time, the flow direction is well thought out and does not allow flow disruption. The gap formed by the flap narrows towards the edge, which allows the passing flow to receive maximum energy. On modern aircraft, slotted flaps are installed, consisting of several sections, which can form from one to three slits. Using such flaps, the aircraft gains lift up to 90%.

The Flaurea flap has a retractable design. The difference is the ability to extend not only backwards, but also downwards. This significantly increases the overall curvature of the aircraft's wing profile. This extension can create up to three slits. The increase in lifting force reaches 100%.

Junkers flap. It is made like a slotted flap, only its upper part serves as an aileron. This allows for better control of the aircraft's roll. The inner two parts of the structure perform the work of the flap. This design was used in the Ju 87 attack aircraft.

Jungmann design flap. This design was first installed on a British-made carrier-based fighter such as the Firefly. By increasing the wing area and lifting force, they were planned to be used at all stages of the flight.

Goudge flap. The main objective of the design was to reduce speed during landing. In addition to changing the curvature, they also increased the area of ​​the wing itself. This design made it possible to reduce the takeoff speed during takeoff. The inventor of this scheme is the English designer A. Goudge, who worked hard on aerodynamic schemes. They were equipped with the Short Stirling aircraft in 1936.

Blow-type flap. This design had a high-quality control system for the upper boundary layer. Blowing made it possible to significantly improve the characteristics of the device during landing. This design made it possible to ensure a high-quality overall flow around the wings. It is known that the boundary layer arises due to the occurrence of viscous friction of the air flow on the surface of the aircraft, while the flow velocity near the skin is zero. It is through the system of influence on this layer that the flow can be prevented from stalling.

Jet flap. It provides a powerful air flow in the plane of the wing, which flows out from the lower surface. This changes the streamlining and increases the lift of the device. As lifting force increases, more air flow is required. It is worth noting that the effectiveness of this design decreases significantly as the overall wing aspect ratio decreases. Near the ground, such flaps do not justify the designers' calculations. Because of this, they are not widely used in the aircraft industry.

The stationary Gurney flap is represented by a perpendicular plane, which is installed at the end of the wings.

The Coandé flap has a constant surface curvature. It is designed for the so-called Coandé effect - when the jet sticks to the surface of the wing, which is subject to blowing.

Designers around the world are still working fruitfully to improve the aerodynamic properties of aircraft.

The plane's flaps could have caused the Tu-154 crash on December 25 near Sochi. This version was put forward by experts after deciphering the data from one of the black boxes.

Airplane flaps: what they are for, photo, why they are needed during takeoff and landing

The cause of the Tu-154 crash in Sochi could have been flaps. According to a preliminary analysis of data obtained from one of the black boxes, the development of an emergency situation on board could begin with the flaps not being retracted for some reason.

Trying to compensate for the resulting diving moment, the pilots aggravated the situation to a critical level by raising the nose of the plane excessively.

As Life reports, citing a source close to the investigation, experts were able to decipher the recording from the voice flight recorder without any problems. According to him, the conversation is interrupted by one of the pilots exclaiming: “Flaps, s...a!” Then a cry sounds: “Commander, we are falling!”

- Speed ​​300... (Inaudible)
- (Inaudible)
- I took the racks, commander.
- (Inaudible)
- Wow, oh my!
(A sharp signal sounds)
- Flaps, s...a, what the f***!
- Altimeter!
- We... (Inaudible)
(The proximity alarm sounds)
- (Inaudible)
- Commander, we are falling!

What are airplane flaps for, photo

Flaps are called wing mechanization elements. When retracted, they are a continuation of the wing surface. When released, they move away from it to form cracks. Flaps are needed to improve the load-bearing capacity of the wing during climb or takeoff/landing. They are also needed when flying at low altitudes.

When the flaps are extended, the curvature of the profile increases, which allows aircraft to fly without stalling at low speeds. The Tu-154M uses double-slot flaps, while the Tu-154B uses three-slot flaps. The flaps can be released either automatically or at the command of the pilots from the cockpit.

According to preliminary data, the flaps on board operated inconsistently; as a result of their failure to release, the lifting force was lost, the speed was not sufficient to gain altitude, and the plane crashed.

Official data on the transcript of the recordings has not yet been published.

Flaps photo

Let us recall that on December 25 at 01:38 Moscow time, the Russian Ministry of Defense Tu-154 plane took off from the Chkalovsky airfield in the Moscow region and was heading to the Khmeimim airbase in Syrian Latakia.

In Sochi, the aircraft stopped for refueling, which was not known in advance. At 05:27 Moscow time, the plane disappeared from radar a few minutes after taking off from Adler airport. Later it became known that the liner fell in the Black Sea near the Sochi coast.

There were 92 people on board the aircraft, all of them died.

Among the victims of the disaster are 64 employees of the Alexandrov Song and Dance Ensemble and its director Valery Khalilov, three film crews, doctor Elizaveta Glinka, who was transporting medicines to Syria, as well as Director of the Department of Culture of the Ministry of Defense Anton Gubankov and crew members.

Flaps- these are special devices on the wing of an aircraft necessary to regulate its load-bearing properties.

The flaps are symmetrically located deflectable surfaces. The flaps are located on the rear of the wing. When retracted, the flaps are an extension of the wing. In the extended position they change the profile of the wing.

Let's see what the flaps look like when retracted and extended.

The flaps, when retracted, form part of the wing profile.

When extended, the flaps significantly change the curvature of the wing, resulting in increased drag and lift.

When the flaps are extended, the curvature of the profile and the surface area of ​​the wing increase. Since the surface area of ​​the wing has increased, the load-bearing capacity of the wing also increases, which allows the aircraft to fly at a lower speed without stalling.

In addition, when the flaps are extended, aerodynamic drag increases, which causes a decrease in speed.

Flaps are typically used to improve the load-bearing capacity of a wing during takeoff, landing, climb and descent, and when flying at low speeds.

How to use flaps in flight simulators

Flight simulators, for example War Thunder, use several different flap positions - takeoff, landing, combat.

In the arcade simulator World of warplanes, the flaps can be in two states - retracted and extended. You can assign a key for releasing the flaps in the game settings.

Flap retracted

Flap extended

Extending the flaps in World of Warplanes, as in real life, will increase the aerodynamic drag of the wing, and, as a result, the speed of the aircraft will begin to drop. This effect is convenient to use when it is necessary to reduce the flight speed, for example, when attacking ground targets or when exiting a dive.

As mentioned earlier, extending the flaps allows you to increase the load-bearing capacity of the wing, and will allow you to fly at low speed without stalling, which turns out to be useful for attack aircraft attacking ground targets at low speed.

Also, the release of flaps allows you to somewhat improve the maneuverability of the aircraft in combat. There is a special one for this - the combat position of the flaps, in World of warplanes the situation is somewhat simplified, there is only one option - the flaps are extended. Extending the flaps in a turn can make the turn more abrupt, but remember that the flaps slow down your plane, so watch your speed and control the engine thrust.

And most importantly, flaps in WoWp are needed only in some combat situations, which are described above. Don't forget to release the button and retract the flaps.

On Tuesday, the main “black box” of the Tu-154 that crashed in Sochi was delivered to Moscow. The Life publication published a transcript, the authenticity of which was not officially confirmed, but it followed from it that the crew had problems with the flaps. And an Interfax source, in turn, said that the Tu-154 could have crashed due to a “stall” with insufficient wing lift for takeoff.

“According to preliminary data, the flaps on board operated inconsistently, as a result of their failure to release, the lifting force was lost, the speed was not sufficient to gain altitude, and the plane crashed,” said a source at the operational headquarters for work at the scene.

Novaya Gazeta asked experts to comment on the version with flaps.

Andrey Litvinov

1st class pilot, Aeroflot

— Flaps are very critical. We ( pilots — ed.) at the very beginning they assumed that these were flaps - as soon as it became clear that it was not fuel or weather. There were several versions - technical, pilot error. But it can be both. A technical problem resulted in a pilot error.

Flaps are needed only for takeoff and landing - the wing area increases, the lifting force increases, therefore, the plane needs a shorter takeoff distance than without flaps. You take off with the flaps, gain altitude, and the flaps retract. But they may not clean up if something is broken, or they may not clean up synchronously - one is faster, the other is slower. If they don’t clean up at all, it’s not a big deal; the plane flies on and on. He doesn't go into a dive. The commander simply reports to the ground that he has such a technical problem, returns to the airfield and lands - with the flaps extended, as required during a normal landing. And engineers are already figuring out what the problem is.

But if they are removed asynchronously, then the plane crashes, that’s what’s scary. On one plane of the wing the lift force becomes greater than on the second, and the plane begins to roll and, as a result, falls on its side. If the plane falls over, dives, and begins to lower its nose, the crew instinctively begins to pull the yoke towards themselves and increase the engine speed - this is absolutely normal. But the pilot must control the spatial position of the aircraft.
There is a concept - supercritical angle of attack. This is the angle at which air begins to escape from the wing. The wing becomes at a certain angle, its upper part is not flown around by air, and the plane begins to fall, because nothing is holding it in the air.

I flew the TU-154 for 8 years. I had no problems with the flaps, there were minor failures, nothing serious. It was a good reliable plane in its time. But that was 25 years ago. It is a product of its time. Aeroflot has all new planes - we fly Airbuses and Boeings. And the Ministry of Defense flies the TU-154. Yes, you need to make your own planes, yes, but at least let them take a superjet. Modern aircraft have a lot of protection systems; it is actually a flying computer. If some situation happens, the automation prevents the plane from stalling and is very helpful to the pilot. These same planes are all in manual mode, all in manual control. But this does not mean that it should fall, it must be technically sound. It must undergo maintenance. The question for the technicians is why such a serious breakdown occurred on this plane. Anyone can make a mistake. The crew does have experience, but military pilots generally don’t fly much. A military pilot flies 150 hours a year. And civilian - 90 hours per month.

Surprise could also have worked, they did not expect such a development of events, they did not have enough reaction to cope. This does not mean that they are inexperienced. Don't forget that the time was 5 am. Just sleep, the body is relaxed, the reaction is initially inhibited. We have been saying for a long time that we should ban night flights or reduce them to a minimum, we should strive to fly during the day, this is what many European companies do.

You also need to remember that the plane was heavy; the fuel tanks, cargo, and passengers were full. There was little time to make a decision. They didn't have time. This situation, of course, must be worked out. I don’t know how the army trains pilots, but here at Aeroflot it’s being worked on. There is an algorithm of actions for every emergency situation. Everything is endlessly practiced on the simulator. Did this crew go to the simulator when? If you were on the simulator, did you practice specific flap exercises? We are waiting for answers from the investigation.

Source close to the investigation

— Now the entire technical investigation is being conducted by the Ministry of Defense. This is a military aircraft - the Air Force Institute in Lyubertsy is engaged in deciphering the recorders, and all recorders, units, systems were transported to Lyubertsy. Flaps are not a critical situation, but in principle a controlled and manageable situation. There is an algorithm for actions in case of desynchronization or incorrect position of the flaps. Pilots are trained in everything, including in simulators; for every emergency, the flight crew practices how to behave, how to control the aircraft. Each aircraft has its own specifics; algorithms have been developed for the Tu-154. A combination of technical problems and human factors can be assumed, but there is still not enough information.

Vadim Lukashevich

Independent aviation expert, candidate of technical sciences

— Failure to retract the flaps is not a disaster. This is a very unpleasant event, but nothing bad should happen from it. And in my opinion, a combination of circumstances and the actions of the crew led to the disaster in the Black Sea.

The essence of airplane flaps is to increase the lift of the wing at low speeds. How a wing works - the higher the speed, the greater the lift. But when the plane takes off, the speed is still low, the same as during landing. And in order to prevent the lift force from decreasing when the speed drops, the flaps in question are extended. You also need to understand that during takeoff the flaps do not extend as much as during landing. When the aircraft is taxiing on the runway, the flaps are already extended, and at the moment of takeoff, the landing gear is sequentially retracted, braking the aircraft, and after 15-20 seconds the flaps are also retracted, hindering the plane as its speed increases. In addition to lifting force, they also create additional air resistance and an additional diving moment - when the plane “wants” to lower its nose.

What happened at the time of the disaster? A heavy, loaded plane, filled with fuel, takes off, the pilots retract the flaps, but for some reason this does not work. In theory, you can continue the flight normally and in this state, without picking up speed, you can turn around and land to fix the problem. It is possible to land with the flaps in this position, but the landing speed will be higher and it will not be very easy. But obviously there was no such solution here. Perhaps the problem with the flaps was not noticed immediately, and when the plane began to lower its nose, words deciphered from the recorder may have been spoken.

The term “wing mechanization” in English sounds like “high lift devices”, which literally means devices for increasing lift. This is precisely the main purpose of the wing mechanization, and where are the planes related to the wing mechanization and how to increase the lift force, as well as why this is needed - this article will tell you.

Wing mechanization is a list of devices that are installed on the wing of an aircraft to change its characteristics during different stages of flight. The main purpose of an airplane wing is to create lift. This process depends on several parameters - the speed of the aircraft, air density, wing area and its lift coefficient.

Wing mechanization directly affects the wing area and its lift coefficient, and also indirectly affects its speed. The lift coefficient depends on the curvature of the wing and its thickness. Accordingly, we can conclude that the mechanization of the wing, in addition to the wing area, also increases its curvature and profile thickness.

In fact, this is not entirely true, because increasing the thickness of the profile is associated with greater technological difficulties, is not as effective and leads more to an increase in drag, therefore this point must be discarded; accordingly, the mechanization of the wing increases its area and curvature. This is done with the help of moving parts (planes) located at certain points of the wing. Based on location and function, the wing mechanization is divided into flaps, slats and spoilers (interceptors).

Airplane flaps. Main types.

Flaps are the first type of wing mechanization invented, and they are also the most effective. They were widely used even before the Second World War, and during and after it their design was refined and new types of flaps were also invented. The main characteristics that indicate that this is indeed a flap are its location and the manipulations that occur with it. The flaps are always located on the trailing edge of the wing and always go down, and, moreover, can be extended back. When the flap is lowered, the curvature of the wing increases, and when it extends, the area increases. And since the lift of a wing is directly proportional to its area and lift coefficient, then if both quantities increase, the flap performs its function most effectively. According to their design and manipulation, flaps are divided into:

• simple flaps (the very first and simplest type of flaps)
• shield flaps
• slotted flaps
• Fowler flaps (the most effective and most widely used type of flap in civil aviation)

How all of the above flaps function is shown in the diagram. A simple flap, as can be seen from the diagram, is simply the trailing edge of the wing deflected down. Thus, the curvature of the wing increases, but the low pressure area above the wing decreases, therefore simple flaps are less effective than shield flaps, the upper edge of which does not deviate and the low pressure area does not lose in size.

The slotted flap gets its name from the gap it creates after deflection. This gap allows the air stream to pass to the low pressure area and is directed in such a way as to prevent stall (a process during which the amount of lift drops sharply), giving it additional energy.

The Fowler flap extends back and down, thereby increasing both the area and curvature of the wing. As a rule, it is designed in such a way that when it is pulled out, it also creates a gap, or two, or even three. Accordingly, it performs its function most efficiently and can provide an increase in lifting force of up to 100%.

Slats. Main functions.

Slats are deflectable surfaces on the leading edge of the wing. In their structure and functions, they are similar to Fowler flaps - they deflect forward and down, increasing the curvature and slightly the area, forming a gap for the passage of air flow to the upper edge of the wing, thereby increasing the lift force. Slats that are simply deflected downwards and do not create a gap are called deflected leading edges and only increase the curvature of the wing.

Spoilers and their tasks.

Spoilers. Before considering spoilers, it should be noted that when creating additional lift, all of the above devices create additional drag, which leads to a decrease in speed. But this occurs as a consequence of an increase in lift, while the task of spoilers is specifically to significantly increase drag and press the aircraft to the ground after touching down. Accordingly, this is the only wing mechanization device, which is located on its upper surface and deflects upward, which creates downforce.