What is an air pocket? Airplane flight. Aviation of the future: passenger drones, supersonic and biodesign

Image copyright Airbus Image caption An example of what the Airbus powertrain might look like in the future. Instead of the usual "skeleton" of frames, stringers and spars - a light mesh of complex shape

Is it possible that the very concept of flight is completely changed? It is possible that this will be the case in the future. Thanks to new materials and technologies, passenger drones may appear, and supersonic airliners will return to the sky. The BBC Russian service analyzed information about the latest projects of Airbus, Uber, Toyota and other companies to determine in which direction aviation will develop in the future.

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urban sky

Now, a fairly large layer of the atmosphere up to a kilometer high remains relatively free over cities. This space is used by special aviation, helicopters, as well as individual private or corporate aircraft.

But in this layer, a new type of air transport is already beginning to develop. It has many names - urban or personal aviation, the air transport system of the future, sky taxi and so on. But its essence was formulated at the beginning of the 19th century by futurologists: everyone will have the opportunity to use a small aircraft for flights over short distances.

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Engineers never parted with this dream. But until now, the lack of strong and lightweight materials and imperfect electronics, without which it is impossible to launch many small devices, have interfered. With the advent of high-strength and lightweight carbon fiber and the development of portable computers, everything has changed.

The current stage in the creation of urban airmobile transport is somewhat reminiscent of the 1910s, the very beginning of the history of aircraft construction. Then the designers did not immediately find the optimal shape of the aircraft and boldly experimented, creating bizarre designs.

Now the common task - to make an aircraft for the urban environment - also allows you to build a wide variety of devices.

Airbus Corporation, for example, is developing three major projects at once - a manned single-seat Vahana, which, according to the plans of the corporation, will be able to fly next year, and by 2021 will be ready for commercial flights. Two other projects: CityAirbus, an unmanned multi-person quadcopter taxi, and Pop.Up, which the corporation is developing with Italdesign. This is a single-seat unmanned module that can be used on a wheeled chassis to travel around the city, as well as suspended from a quadcopter for flights.

Airbus Pop.Up and CityAirbus use the principle of a quadcopter, and Vahana is a tiltrotor (that is, an apparatus that takes off like a helicopter, and then turns the engines and moves on like an airplane).

Quadcopter and tiltrotor schemes are now the main ones for passenger drones. Quadcopters are much more stable while flying. And convertiplanes allow you to develop greater speed. But both schemes allow you to take off and land vertically. This is a key requirement for urban aviation, since conventional aircraft need a runway. And this means that the construction of additional infrastructure for the city will be required.

Other notable projects include the German company eVolo's Volocopter, which is a multicopter with 18 propellers. This is the most successful air taxi project so far, and in the fall of 2017, Dubai has already begun testing it. In June, Dubai's transport management company talked about it with eVolo.

Another project from Germany - Lilium - is interesting for its unusual layout. This is an electric tiltrotor for 36 small turbines, installed in two blocks along the wing, and with two more blocks in front of the device. The company has already begun test flights in unmanned mode.

Japanese automaker Toyota is investing in the Cartivator project.

And the online taxi service Uber is also developing its unmanned system, in this project it is working closely with NASA to develop technology and software for service in cities with high population density.

Among aviation experts, there are many both supporters of unmanned urban passenger transportation and skeptics.

Among the latter is the editor-in-chief of Avia.ru Roman Gusarov. The main problem, in his opinion, is the low power of electric motors and batteries. And effective passenger drones are unlikely to appear in the foreseeable future, despite the fact that a lot of money is being invested in their development.

"Technologies are still quite crude and the systems created with their use are subject to technical failures," Denis Fedutinov, editor-in-chief of the uav.ru portal, said in an interview with the BBC.

According to him, such projects can be just a beautiful publicity stunt and an opportunity to show that the company is engaged in cutting-edge research. He also does not rule out that against the backdrop of enthusiastic publications in the press, many startups may appear, which, having found investors' money, will not be able to create a flying passenger drone.

Executive Director of Infomost Consulting (a company engaged in consulting in the field of transport) Boris Rybak believes that fear is the biggest problem in this area so far. People will be afraid to trust their lives to an aircraft without a pilot for a long time to come.

“When the first self-propelled gasoline carts appeared, they rode with fumes, smoke and roar next to the horses, and the people scattered. But this is normal, then it was scary, and now it’s scary,” said Rybak.

Between the houseamiand birdsami

NASA and the US Federal Aviation Administration are currently working on the Unmanned Aircraft System (UAS) Traffic Management (UTM) program. It is under this program that Uber is partnering with NASA and the FAA.

The development of technologies in this area is far ahead of the development of rules for their regulation. The American program began to be developed in 2015, but the roadmap for its development has not even indicated the deadline for creating rules for flights in densely populated urban areas.

This refers to the flights of drones for the delivery of mail and news video filming. And so far nothing is said about the transportation of passengers in the program.

According to the presentations studied by the BBC Russian Service, in the future, flights of passenger drones in cities will be regulated through building routes in air corridors. The same principle operates in modern civil aviation. At the same time, the drones will actively interact with each other and monitor the airspace around in order to avoid collisions with other drones and other objects in the air (for example, with birds).

However, as Boris Rybak believes, a system built on the principle of free flight would be much more effective, where the routes would be lined up by computers, taking into account the location of all devices in the air.

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Will Russia stay away?

In Russia, authorities are also trying to take cautious steps to regulate drone flights in urban environments. So, Rostelecom has been interested in drones for a long time. It is a contractor for Russian Space Systems, which in November 2015 won a 723 million ruble ($12.3 million) competition from Roscosmos to build the infrastructure of the Federal Grid Operator.

This infrastructure will have to provide monitoring of transport and unmanned vehicles (including aircraft), ground and water manned and unmanned vehicles, railway transport, the representative of Rostelecom explained. The operator is creating a prototype infrastructure that will control traffic, primarily drones, and is ready to spend about 100 million rubles ($1.7 million) on subcontractors.

Andrey Tikhonov, deputy head of the Department of Science, Industrial Policy and Entrepreneurship in Moscow, told the BBC that there are no conditions for the appearance of passenger drones in the Russian capital yet.

"Firstly, the regulatory framework for unmanned aerial and ground vehicles has not been fully developed. Secondly, the Moscow infrastructure has not yet been adapted for the mass transportation of goods and passengers on unmanned vehicles. goods are still at the testing stage and must receive the appropriate documentation for work in urban conditions. Again, there are questions of compulsory insurance of passengers and many others," he explained.

True, according to him, these problems are not so much stopped by the city authorities as they are forced to look for ways to solve them.

faster than sound

Another area that many aircraft corporations are working on is supersonic passenger transportation.

This idea is not new at all. November 22 marks the 40th anniversary of the start of regular commercial flights between New York, Paris and London on Concorde aircraft. In the 1970s, the idea of ​​supersonic transportation was implemented by British Airways together with Air France, as well as by Aeroflot on the Tu-144. But in practice it turned out that the technologies of that time were not suitable for civil aviation.

As a result, the Soviet project was canceled after seven months of operation, and the British-French one after 27 years.

The main reason why the Concorde and Tu-144 projects were curtailed is usually finances. These planes were expensive.

The engines of such devices consume much more fuel. For such aircraft, it was necessary to create their own infrastructure. The Tu-144, for example, used its own type of aviation fuel, which was much more complex in composition; it needed special maintenance, more thorough and expensive. For this aircraft, even separate ladders had to be kept.

Another major problem, in addition to the complexity and cost of maintenance, was noise. During flight at supersonic speed, a strong air seal occurs on all leading edges of the aircraft elements, which generates a shock wave. It stretches behind the plane in the form of a huge cone, and when it reaches the ground, the person through whom it passes hears a deafening sound, similar to an explosion. It was because of this that Concorde flights over the United States at supersonic speeds were banned.

And it is with the noise now, first of all, that the designers are trying to fight.

After the cessation of Concorde flights, attempts to build a new, more efficient supersonic passenger aircraft did not stop. And with the advent of new technologies in the field of materials, engine building and aerodynamics, they began to be talked about more and more often.

Several major projects in the field of supersonic civil aviation are being developed in the world at once. Basically, these are business jets. That is, designers initially try to target the segment of the market where the cost of tickets and services plays a smaller role than in route transportation.

NASA is working with Lockheed Martin to develop a supersonic aircraft in an attempt to solve the sound barrier problem in the first place. QueSST technology involves finding a special aerodynamic shape of the aircraft, which would "smear" the hard sound barrier, making it blurry and less noisy. Currently, NASA has already developed the appearance of the aircraft, and its flight tests may begin in 2021.

Another notable project is AS2, which is being developed by Aerion in partnership with Airbus.

Airbus is also working on the Concord 2.0 project. This aircraft is planned to be equipped with three types of engines - rocket in the tail section and two conventional jets, with which the aircraft will be able to take off almost vertically, as well as one ramjet, which will already accelerate the device to a speed of Mach 4.5.

True, such projects are being dealt with quite cautiously in Airbus.

"Airbus continues research into supersonic/hypersonic technologies, we are also studying the market to see if these kinds of projects are viable and feasible," Airbus said in an official comment to the BBC Russian Service. "We do not see a market for such aircraft now and for the foreseeable future due to the high costs of such systems. This may change with the advent of new technologies, or with changes in the economic or social environment. In general, for now this is more of an area of ​​study, not a priority."

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It is really difficult to predict whether there will be demand for such aircraft. Boris Rybak notes that in parallel with aviation, information technologies have also developed, and now a businessman who needs to quickly resolve an issue on the other side of the Atlantic can often do this not in person, but via the Internet.

"Flying in business class or in a business jet takes six hours from London to New York. Otherwise, you will technically spend four, well, three forty. Is this [gameskin] worth the candle?" Rybak said about supersonic flights.

According to the experience of Tu-144

However, other Russian aviation experts think otherwise. Supersonic aircraft will be able to take their place in the market, says Mikhail Pogosyan, rector of the Moscow Aviation Institute, former head of the United Aircraft Corporation.

"A supersonic aircraft makes it possible to reach a qualitatively different level, it allows you to save global time - a day. Market forecasts indicate that the introduction of such technologies and such projects will be associated with the cost of such a flight. If such a cost is acceptable and will not be in times different from the cost of a flight on a subsonic aircraft, then I assure you that there is a market," he told the BBC Russian Service.

Pogosyan spoke at the Aerospace Science Week forum at the Moscow Aviation Institute, where he, in particular, spoke about the prospects for creating a supersonic aircraft with the participation of Russian specialists. Russian enterprises (TsAGI, MAI, UAC) are participating in the large European research program Horizon 2020, one of the areas of which is the development of a supersonic passenger aircraft.

Pogosyan listed the main properties of such an aircraft - a low level of sonic boom (otherwise the aircraft will not be able to fly over populated areas), a variable cycle engine (it needs to work well at subsonic and supersonic speeds), new heat-resistant materials (at supersonic speed the aircraft gets very hot), artificial intelligence, as well as the fact that one pilot can fly such an aircraft.

At the same time, the rector of the Moscow Aviation Institute is convinced that the project of a supersonic aircraft can only be created at the international level.

The head of the Central Aerohydrodynamic Institute named after Professor N. E. Zhukovsky (TsAGI) Sergey Chernyshev said at the forum that Russian specialists are involved in three international projects in the field of supersonic passenger aviation - Hisac, Hexafly and Rumble. All three projects do not aim to create a final commercial product. Their main task is to investigate the properties of supersonic and hypersonic vehicles. According to him, now aircraft manufacturers are only creating the concept of such an aircraft.

In an interview with the BBC, Sergey Chernyshev said that the strength of Russian aircraft manufacturers is the experience in creating supersonic aircraft and their operation. According to him, this is a strong aerodynamic school, extensive experience in testing, including in extreme conditions. Russia also has a "traditionally strong school of materials scientists," he added.

"My subjective forecast: [a business jet] will appear on the horizon of 2030-35. Academician Poghosyan believes that between 2020 and 2030. He gave them ten years. This is true, but still closer to 2030," Sergey Chernyshev said.

"Ordinary" unusual liners

The main task of aircraft designers today is to achieve an increase in the fuel efficiency of the aircraft, while reducing harmful emissions and noise. The second task is to develop new control systems, where the computer will perform more and more tasks.

Now no one can be surprised by the fly-by-wire aircraft control system, when signals from the control stick or steering wheel, pedals and other organs are transmitted to the rudders and other elements of mechanization in the form of electrical signals. Such a system allows the on-board computer to control the actions of the pilot, making adjustments and correcting errors. However, this system is already yesterday.

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Kirill Budaev, vice president of marketing and sales at Irkut Corporation, told the BBC that the Russian company is working on a system where only one pilot will fly the aircraft, and a specially trained senior flight attendant will perform the functions of the second during takeoff and landing. During the flight of an aircraft at flight level, one pilot is enough, according to Irkut.

According to the laws of nature

Another major innovation that has appeared in the last decade is composite materials. The development of light and strong plastics can be compared to the use of aluminum in post-war aviation. This material, together with the advent of efficient turbojet engines, changed the face of aircraft. Now exactly the same revolution is happening with the composite, which is gradually replacing metal from aircraft structures.

Aircraft design is increasingly using 3D printing, which allows more complex shapes to be created with high precision. And to reduce fuel consumption.

Airbus and Boeing, for example, use the latest LEAP engines from CFM International. The injectors in these engines are 3D printed. And this allowed to increase fuel efficiency by 15%.

In addition, now the aviation industry has begun to actively develop bionic design.

Bionics is an applied science that studies the possibilities of practical application in various technical devices of the principles and structures that have appeared in nature due to evolution.

Here's a simple example - the picture above shows a bracket similar to the one used on an Airbus aircraft. Pay attention to its shape - usually such an element is a solid piece of triangular metal. However, by calculating on a computer the forces that would be applied to its various parts, the engineers figured out which parts could be removed and which parts could be modified in such a way as not only to lighten, but also to strengthen such a component.

Much more complex work was carried out by a group of scientists led by a professor at the Technical University of Denmark, Niels Aage. In October 2017, they published a report in the journal Nature, in which they talked about how they calculated the force set of a Boeing 777 airliner wing - a complex structure of rather thin jumpers and struts - on the French Curie supercomputer.

As a result, according to the researchers, the weight of the two wings of the aircraft could be reduced by 2-5% without losing strength. Considering that both wings weigh 20 tons in total, this would give a saving of up to 1 ton, which corresponds to an estimated reduction in fuel consumption of 40-200 tons per year. But this is essential, isn't it?

At the same time, the bionic design in the future, according to aircraft manufacturing corporations, will be used more and more. The aircraft in the first illustration to this text is only a sketch of Airbus engineers, but it already shows the principle by which the power set of aircraft of the future will be created.

Electricity

The engine is the most important and most expensive part of an aircraft. And it is he who determines the configuration of any aircraft. Currently, most aircraft engines are either gas generators or internal combustion, gasoline or diesel engines. Only the smallest part of them works on electricity.

According to Boris Rybak, the development of fundamentally new aircraft engines has not been carried out for all the decades of the existence of jet aviation. He sees this as a manifestation of the lobby of oil corporations. Like it or not, but for the entire post-war period, an effective engine that would not burn hydrocarbon fuel did not appear. Although even atomic ones were tested.

Now in the global aviation industry, the attitude towards electricity is changing dramatically. The concept of "More Electric Aircraft" has appeared in world aviation. It implies a greater electrification of the units and mechanisms of the apparatus compared to modern ones.

In Russia, technologies within the framework of this concept are handled by the Technodinamika holding, which is part of Rostec. The company develops electric reverse drives for the future Russian PD-14 engine, drives for the fuel system, retraction and extension of the landing gear.

“In the long term, we are certainly considering large commercial aircraft projects. And in these large aircraft, we will most likely use a hybrid propulsion system before moving completely to electric propulsion,” Airbus said in a comment. The power-to-weight ratio in modern batteries is still very far from what we need, but we are preparing for a future where this is possible."

Small unmanned aerial vehicles are becoming more common every year - they are used in filming TV shows and music videos, for patrolling territories, or just for fun. Drones do not require special permission, and their cost is constantly decreasing. As a result, the aviation authorities of some countries decided to study whether these devices pose a danger to passenger aircraft. The results of the first studies turned out to be contradictory, but in general, regulators came to the conclusion that flights of private drones should be taken under control.

In July 2015, a Lufthansa plane landing at Warsaw Airport almost collided with a multicopter flying at a distance of less than a hundred meters from it. In April 2016, the pilots of a British Airways passenger plane that landed at London Airport reported to the air traffic controllers that they had collided with a drone while landing. Later, however, the investigation concluded that there was no drone, and what the pilots took for it was most likely an ordinary package lifted by the wind from the ground. However, already in July 2017, at the British Gatwick airport, the plane almost collided with a drone, after which the controllers were forced to close one runway for landing and redirect five flights to reserve lanes.

According to the British research organization UK Airprox Board, in 2016 in the UK there were 71 cases of dangerous proximity of passenger aircraft with drones. In aviation, a close proximity is considered to be an aircraft approaching another aircraft at a distance of less than 150 meters. Since the beginning of this year, there have already been 64 cases of drones approaching aircraft in the UK. In the United States, aviation authorities registered just under 200 cases of dangerous proximity last year. At the same time, the aviation authorities still have a poor idea of ​​how dangerous small drones can be for passenger aircraft. Some experts have previously suggested that a collision with a drone for a passenger liner would be no more dangerous than a regular collision with birds.

According to Aviation Week & Space Technology, since 1998, 219 people have died worldwide due to a mid-air collision between passenger flights and birds, and a significant number of them flew in small private jets. At the same time, airlines around the world spend a total of $625-650 million annually to repair damage to passenger aircraft due to bird strikes. By the way, in general, passenger liners are considered resistant to direct hit by birds. During the development and testing of new aircraft, special checks are even carried out - the aircraft is fired upon with the carcasses of various birds (ducks, geese, chickens) to determine its resistance to such damage. Checking the engines for throwing birds into them is generally mandatory.

In mid-March last year, researchers from the American George Mason University, in which they announced that the threat of drones to aviation is greatly exaggerated. They studied the statistics of aircraft strikes with birds from 1990 to 2014, including episodes that ended in human casualties. As a result, scientists came to the conclusion that the real probability of a dangerous collision of a drone with an aircraft is not so great: only one case in 187 million years should end in a large-scale catastrophe.

To try to determine whether drones are indeed a threat to passenger aircraft, two independent studies were commissioned in 2016 by aviation authorities in the European Union and the UK. The engineers who conduct these studies bombard various aircraft fragments with drones of various designs or their parts in order to cause real damage that passenger aircraft can receive in a collision. In parallel, mathematical modeling of such collisions is carried out. Research is carried out in several stages, the first of which has already been completed, and the results are presented to customers. As expected, after the completion of the work, the aviation authorities will develop new rules for the registration and operation of drones by private individuals.

Drone crashes into the windshield of a passenger plane during testing in the UK

Today, in different countries there are no uniform rules for flying drones. For example, in the UK it is not required to register and license drones weighing less than 20 kilograms. At the same time, these devices must perform flights in the line of sight of the operator. Private drones with cameras cannot fly up to people, buildings and cars at a distance closer than 50 meters. In Italy, there are practically no special rules for drones, except for one thing - drones cannot be flown by a large crowd of people. And in Ireland, for example, all drones weighing more than one kilogram must be registered with the country's Civil Aviation Authority. By the way, in the European Union, Ireland is one of the ardent supporters of tightening the rules for the use of drones.

Meanwhile, while in Europe they plan to tighten the screws, in the United States, on the contrary, they intend to make drone flights more free. So, at the beginning of this year, the US Federal Aviation Administration came to the conclusion that light consumer quadrocopters do not pose a big threat to aircraft, although their flights near airports are unacceptable. In February, American companies 3DR, Autodesk and Atkins already received permission to fly drones at the world's busiest airport, Hartsfield-Jackson Atlanta International Airport, which handles about a hundred million passengers annually. Here, quadcopters were used to produce high-resolution 3D maps of the airport. They flew in the line of sight of the operator and under the control of air traffic controllers.

The results of the study were first published by a working group of the European Aviation Safety Agency in October last year. These researchers concluded that amateur drones do not pose a serious threat to passenger aircraft. The members of the working group during their work focused on studying the consequences of air collisions between passenger aircraft and drones weighing up to 25 kilograms. For the study, drones were divided into four categories: large (weighing more than 3.5 kilograms), medium (up to 1.5 kilograms), small (up to 0.5 kilograms) and “harmless” (up to 250 grams). For each category, experts determined the degree of danger, which was assessed on a five-point scale: 1-2 - high, 3-5 - low. Devices that received four or five points were considered safe.

To determine the degree of danger, the researchers used data on the flight altitudes of vehicles by category, took into account the likelihood of their appearance in the same airspace with aircraft, as well as the results of computer and full-scale tests of the collision of drones and airliners. In addition, the individual degree of danger was assessed for each unmanned vehicle on four points: damage to the hull, threat to the life of passengers, threat to the life of the crew, threat of violation of the flight schedule. To simplify the assessment, the researchers conducted calculations for aircraft flying at a speed of 340 knots (630 kilometers per hour) at an altitude of three thousand meters or more and at a speed of 250 knots at a lower altitude.

Based on the results of all calculations, the participants of the European working group came to the conclusion that small drones at an altitude of up to three thousand meters practically do not pose a threat to passenger aircraft. The fact is that such devices to a great height, where they can collide with an aircraft, are extremely rare. In addition, they have a very small mass. Medium drones, according to experts, do not pose a serious threat to airliners. Only if a device weighing 1.5 kilograms (most amateur drones have such a mass) collides with an aircraft at an altitude of more than three thousand meters, can it threaten flight safety. Large devices are recognized as dangerous for passenger aircraft at all flight altitudes.

According to the results of full-scale tests, it turned out that in the event of a collision with drones, the windshields of the airliners, nose cones, wing leading edges, and engines can receive the most damage. In general, the damage from drones weighing up to 1.5 kilograms can be comparable to the damage from birds that aircraft regularly encounter in the air. Now, European experts are preparing for an expanded study. This time, the damage that drones can cause to the engines of passenger aircraft will be studied, as well as the likelihood of batteries falling into technological holes.

By the way, earlier scientists from the Virginia Polytechnic University conducted computer simulations of situations in which various drones fall into a working aircraft engine. The researchers concluded that vehicles weighing more than 3.6 kilograms pose a serious danger to engines. Once in the engine, they will destroy the fan blades and collapse themselves. Then the fragments of the fan blades and the drone will fall into the external air circuit, from where they will be thrown out, as well as into the internal circuit - the compressor, the combustion chamber and the turbine zone. The speed of debris inside the engine can reach 1150 kilometers per hour. Thus, in a collision during takeoff with a drone weighing 3.6 kilograms, the engine will completely stop working in less than a second.

Meanwhile, the results of the British study were summed up in the middle of this year - in July, the company QinetiQ, which carried out the work, handed over the report to the National Air Traffic Control Service of Great Britain. The study, conducted by a British company, used a specially designed air gun that fired drones and their parts at predetermined speeds at the front of decommissioned planes and helicopters. For shooting, quadrocopters weighing 0.4, 1.2 and 4 kilograms, as well as aircraft-type drones weighing up to 3.5 kilograms, were used. Based on the results of the shooting, experts came to the conclusion that any drones are dangerous for light aircraft and helicopters that do not have a special certificate of protection against bird strikes.

Bird-proof passenger aircraft can be seriously damaged by drones when flying at cruising speeds that range from 700 to 890 kilometers per hour. The researchers attributed the destruction of the windshields in a collision with heavy parts of the drones - metal body parts, a camera and a battery - to serious damage. These parts, breaking through the windshield, can fly into the cockpit, damage the control panels and injure the pilots. Dangerous for the liners were considered devices weighing from two to four kilograms. It should be noted that passenger aircraft develop cruising speed already at a high altitude (usually about ten thousand meters), which amateur drones are simply unable to climb.

According to QinetiQ, drones weighing four kilograms can be dangerous for passenger aircraft at low flight speeds, such as when landing. At the same time, the severity of damage to the aircraft largely depends on the design of the drone. So, during the tests, it turned out that drones with a camera placed on a suspension under the body have a small chance of breaking through the windshield of a passenger aircraft. The fact is that in a collision with glass, the camera on the suspension will first hit, and then the body of the drone. In this case, the camera and its suspension will play the role of a kind of shock absorber, taking on part of the impact energy. The UK aviation authorities, who are pushing for a drastic tightening of drone regulations, are expected to order an additional study.

Some of the drones that are being mass-produced today already have the geofencing function. This means that the device is constantly updating the database of areas closed to drone flights. In such a zone, the drone simply will not take off. However, in addition to serial devices, there are home-made drones that can fly into the airspace of airports. And there are quite a few of them. In general, so far not a single case of a collision between an aircraft and a drone has been registered, but this is just a matter of time. And even if small drones do not pose a serious threat to passenger aircraft, they can still have a negative impact on aviation, increasing the already considerable costs for companies to repair liners.

Vasily Sychev

An amazing sight is a cone of steam that appears around an aircraft that flies at transonic speeds. This amazing effect, known as the Prandtl-Gloert effect, causes the eyes to open wide and the jaw to drop. But what is its essence?

(Total 12 photos)

1. Contrary to popular belief, this effect does not appear when the aircraft breaks the sound barrier. The Prandtl-Gloert effect is also often associated with supersonic popping, which is also not true. Ultra high bypass aircraft engines can create this effect at takeoff speed because the engine inlet is low pressure and the fan blades themselves operate at transonic speeds.

2. The reason for its occurrence is that an aircraft flying at high speed creates an area of ​​high air pressure in front of itself and an area of ​​low pressure behind. After the flight of the aircraft, the area of ​​low pressure begins to fill with ambient air. In this case, due to the rather high inertia of the air masses, the entire low-pressure area is first filled with air from nearby areas adjacent to the low-pressure area.

3. Imagine an object moving at transonic speed. Transonic speed is different from the speed of sound. The sound barrier is overcome at a speed of 1235 km / h. Transonic speed is below, above or near the speed of sound and can vary from 965 to 1448 km/h. Therefore, this effect can appear when the aircraft is moving at a speed less than or equal to the speed of sound.

4. And yet, it's all about the sound - it is on it that the "visibility" of this steam cone behind the aircraft depends. The shape of the cone is formed by the force of sound (in the case of aircraft) traveling faster than the sound waves it produces. The Prandtl-Gloert effect occurs as a result of the wave nature of sounds.

5. Again, think of the plane as the source and the sound as the crest of the wave. These crests of sound waves are a series or sheath of overlapping circles. When the waves are superimposed on each other, a cone shape is created, and its tip is the source of the sound. So far invisible.

6. For the effect to become visible to the human eye, one more thing is needed - humidity. When the humidity is high enough, the air around the cone condenses and forms the cloud we see. As soon as the air pressure returns to normal, the cloud disappears. The effect almost always occurs with planes flying over the ocean in the summer - the combination of water and heat produces the right level of humidity.

7. Here you can destroy another one. Some believe that the Prandtl-Gloert effect occurs as a result of fuel combustion.

8. You can probably understand if you think that this effect is a contrail, that is, an unnatural cloud that appears from condensed water vapor, which is produced by engine exhaust. However, they are not the same. The water vapor is already there - it's already in the air before the plane passes through it.

9. Air pressure is also worth mentioning. When an aircraft is moving at transonic speed, the air pressure around it is called an N-wave, because when the pressure is time dependent, the result is like the letter N.

10. If we could slow down the blast wave passing through us, we would see the leading compression component. This is the beginning of N. The horizontal stick occurs when the pressure drops, and when the normal pressure of the atmosphere returns to the final point, the letter N is created.

11. The effect is named after two prominent scientists who discovered this phenomenon. Ludwig Prandtl (1875 – 1953) was a German scientist who studied the development of systematic mathematical analysis in aerodynamics. Herman Gloert (1892 – 1934) was a British aerodynamic scientist.

12. Believe it or not, you can create this effect yourself. You only need two things: a stick and a day of high humidity. If you can lash the whip like Indiana Jones, you'll see a similar effect. However, you shouldn't try it at home.

Passed the sound barrier :-) ...

Before jumping into conversations on the topic, let's bring some clarity to the question of the accuracy of concepts (what I like :-)). There are two terms in common use today: sound barrier And supersonic barrier. They sound similar, but still not the same. However, there is no point in diluting it with particular rigor: in fact, this is one and the same thing. The definition of the sound barrier is used most often by people who are more knowledgeable and closer to aviation. And the second definition is usually all the rest.

I think that from the point of view of physics (and the Russian language :-)) it is more correct to say the sound barrier. There is simple logic here. After all, there is the concept of the speed of sound, but there is no fixed concept of the speed of supersonic, strictly speaking. Looking ahead a little, I’ll say that when an aircraft flies at supersonic, it has already passed this barrier, and when it passes (overcomes) it, then it passes a certain threshold value of speed equal to the speed of sound (and not supersonic).

Something like that:-). Moreover, the first concept is used much less frequently than the second. This is apparently because the word supersonic sounds more exotic and attractive. And in supersonic flight, the exotic is certainly present and, of course, attracts many. However, not all people who savor the words " supersonic barrier' really understand what it is. More than once I was convinced of this, looking at the forums, reading articles, even watching TV.

This question is actually rather complicated from the point of view of physics. But we, of course, will not climb into complexity. We will just try, as usual, to clarify the situation using the principle of "explaining aerodynamics on the fingers" :-).

So, to the barrier (sonic :-))!… Aircraft in flight, acting on such an elastic medium as air, becomes a powerful source of sound waves. I think everyone knows what sound waves are in the air :-).

Sound waves (tuning fork).

This is an alternation of areas of compression and rarefaction, propagating in different directions from the sound source. Approximately like circles on the water, which are also just waves (but not sound :-)). It is these areas, acting on the eardrum, that allow us to hear all the sounds of this world, from human whispers to the roar of jet engines.

An example of sound waves.

The points of propagation of sound waves can be various nodes of the aircraft. For example, an engine (its sound is known to anyone :-)), or parts of the body (for example, the nose), which, compacting the air in front of it when moving, create a certain type of pressure (compression) wave running forward.

All these sound waves propagate in the air at the speed of sound we already know. That is, if the plane is subsonic, and even flies at low speed, then they seem to run away from it. As a result, when such an aircraft approaches, we first hear its sound, and then it flies itself.

I will make a reservation, however, that this is true if the plane does not fly very high. After all, the speed of sound is not the speed of light :-). Its magnitude is not so great and sound waves need time to reach the listener. Therefore, the sequence of sound appearance for the listener and the aircraft, if it flies at high altitude, may change.

And since the sound is not so fast, then with an increase in its own speed, the plane begins to catch up with the waves emitted by it. That is, if he was motionless, then the waves would diverge from him in the form concentric circles like circles on the water from a thrown stone. And since the plane is moving, then in the sector of these circles, corresponding to the direction of flight, the boundaries of the waves (their fronts) begin to approach each other.

Subsonic motion of the body.

Accordingly, the gap between the aircraft (its nose) and the front of the very first (head) wave (that is, this is the area where gradual, to a certain extent, braking oncoming flow when meeting with the nose of the aircraft (wing, tail) and, as a result, increase in pressure and temperature) begins to decrease and the faster, the greater the flight speed.

There comes a moment when this gap practically disappears (or becomes minimal), turning into a special kind of area, which is called shock wave. This happens when the flight speed reaches the speed of sound, that is, the aircraft moves at the same speed as the waves emitted by it. The Mach number in this case is equal to one (M=1).

Sound movement of the body (M=1).

shock wave, is a very narrow area of ​​the medium (of the order of 10 -4 mm), when passing through which there is no longer a gradual, but a sharp (jump-like) change in the parameters of this medium - speed, pressure, temperature, density. In our case, the speed drops, pressure, temperature and density increase. Hence the name - the shock wave.

Somewhat simplistically, I would say this about all this. It is impossible to slow down a supersonic flow sharply, but it has to do this, because there is no longer the possibility of gradual deceleration to the speed of the flow in front of the very nose of the aircraft, as at moderate subsonic speeds. It seems to stumble upon a section of subsonic in front of the nose of the aircraft (or the toe of the wing) and collapses into a narrow jump, transferring to it the great energy of movement that it possesses.

By the way, it can also be said vice versa that the aircraft transfers part of its energy to the formation of shock waves in order to slow down the supersonic flow.

Supersonic motion of the body.

There is another name for the shock wave. Moving along with the aircraft in space, it is, in fact, the front of a sharp change in the above parameters of the environment (that is, the air flow). And this is the essence of the shock wave.

shock wave and a shock wave, in general, are equal definitions, but in aerodynamics the first is more commonly used.

The shock wave (or shock wave) can be almost perpendicular to the direction of flight, in which case they take an approximately circular shape in space and are called straight lines. This usually happens in modes close to M=1.

Modes of body movement. ! - subsonic, 2 - M=1, supersonic, 4 - shock wave (shock).

At numbers M > 1, they are already at an angle to the direction of flight. That is, the plane is already overtaking its own sound. In this case, they are called oblique and in space take the form of a cone, which, by the way, is called the Mach cone, after the scientist who studied supersonic flows (he mentioned him in one of).

Mach cone.

The shape of this cone (its “slimness”, so to speak) just depends on the number M and is related to it by the relation: M = 1 / sin α, where α is the angle between the axis of the cone and its generatrix. And the conical surface touches the fronts of all sound waves, the source of which was the aircraft, and which it “overtook”, reaching supersonic speed.

Besides shock waves may also be affiliated, when they are adjacent to the surface of a body moving at supersonic speed or retreated if they do not touch the body.

Types of shock waves in supersonic flow around bodies of various shapes.

Usually, shocks become attached if the supersonic flow flows around any pointed surfaces. For an aircraft, for example, this can be a pointed nose, a PVD, a sharp edge of an air intake. At the same time, they say “jump sits”, for example, on the nose.

And the receding shock can be obtained when flowing around rounded surfaces, for example, the front rounded edge of a thick aerodynamic wing profile.

Various components of the aircraft body create a rather complex shock wave system in flight. However, the most intense of them are two. One head on the bow and the second tail on the elements of the tail unit. At some distance from the aircraft, the intermediate jumps either overtake the head one and merge with it, or the tail one overtakes them.

The shock waves on the aircraft model when blowing in a wind tunnel (M=2).

As a result, two jumps remain, which, in general, are perceived by the earthly observer as one due to the small size of the aircraft compared to the flight altitude and, accordingly, a short time interval between them.

The intensity (in other words, energy) of the shock wave (compression shock) depends on various parameters (the speed of the aircraft, its design features, environmental conditions, etc.) and is determined by the pressure drop at its front.

As the distance from the top of the Mach cone, that is, from the aircraft, as a source of perturbations, the shock wave weakens, gradually turns into an ordinary sound wave and eventually completely disappears.

And on what degree of intensity it will have shock wave(or shockwave) that reaches the ground depends on the effect it can produce there. It's no secret that the well-known Concorde flew supersonic only over the Atlantic, and military supersonic aircraft go supersonic at high altitudes or in areas where there are no settlements (at least it seems like they should do it :-)).

These restrictions are very justified. For me, for example, the very definition of a shock wave is associated with an explosion. And the things that a sufficiently intense shock wave can do may well be up to it. At least the glass from the windows can fly out easily. There is enough evidence of this (especially in the history of Soviet aviation, when it was quite numerous and the flights were intense). But you can do worse things. You just have to fly lower :-) ...

However, for the most part, what remains of shock waves when they reach the ground is no longer dangerous. Just an outside observer on the ground can at the same time hear a sound similar to a roar or explosion. It is with this fact that one common and rather persistent misconception is associated.

People who are not too experienced in aviation science, hearing such a sound, say that this plane overcame sound barrier (supersonic barrier). Actually it is not. This statement has nothing to do with reality for at least two reasons.

Shock wave (compression shock).

Firstly, if a person on the ground hears a booming roar high in the sky, then this only means (I repeat :-)) that his ears have reached shock wave front(or shock wave) from an airplane flying somewhere. This plane is already flying at supersonic speed, and not just switched to it.

And if the same person could suddenly be a few kilometers ahead of the aircraft, then he would again hear the same sound from the same aircraft, because he would be affected by the same shock wave moving along with the aircraft.

It moves at supersonic speeds, and therefore approaches silently. And after it has had its not always pleasant effect on the eardrums (well, when only on them :-)) and safely passes on, the rumble of running engines becomes audible.

Approximate aircraft flight pattern for various values ​​of the M number on the example of the Saab 35 "Draken" fighter. The language, unfortunately, is German, but the scheme is generally understandable.

Moreover, the transition to supersonic itself is not accompanied by any one-time “booms”, pops, explosions, etc. On a modern supersonic aircraft, the pilot most often learns about such a transition only from the readings of the instruments. In this case, however, a certain process occurs, but it is practically not noticeable to him, subject to certain piloting rules.

But that's not all :-). I'll say more. in the form of just some kind of tangible, heavy, difficult-to-cross obstacle, against which the plane rests and which needs to be “pierced” (I have heard such judgments :-)) does not exist.

Strictly speaking, there is no barrier at all. Once upon a time, at the dawn of the development of high speeds in aviation, this concept was formed rather as a psychological belief about the difficulty of switching to supersonic speed and flying at it. There were even statements that it was impossible at all, especially since the prerequisites for such beliefs and statements were quite specific.

However, first things first…

In aerodynamics, there is another term that quite accurately describes the process of interaction with the air flow of a body moving in this flow and striving to switch to supersonic. This wave crisis. It is he who does some of the bad things that are traditionally associated with the concept sound barrier.

So something about the crisis :-). Any aircraft consists of parts, the air flow around which in flight may not be the same. Take, for example, a wing, or rather an ordinary classic subsonic profile.

From the basics of knowledge about how the lifting force is formed, we are well aware that the flow velocity in the adjacent layer of the upper curved surface of the profile is different. Where the profile is more convex it is greater than the total flow velocity, then when the profile flattens it decreases.

When the wing moves in the flow at speeds close to the speed of sound, a moment may come when, for example, in such a convex region, the speed of the air layer, which is already greater than the total flow speed, becomes sonic and even supersonic.

Local shock that occurs on transonic during a wave crisis.

Further along the profile, this speed decreases and at some point again becomes subsonic. But, as we said above, the supersonic flow cannot quickly slow down, so the occurrence of shock wave.

Such shocks appear in different parts of the streamlined surfaces, and initially they are quite weak, but their number can be large, and with an increase in the total flow velocity, supersonic zones increase, the shocks “strengthen” and move towards the trailing edge of the airfoil. Later, the same shock waves appear on the bottom surface of the profile.

Full supersonic flow around the wing airfoil.

What is the risk of all this? But what. First- is significant increase in aerodynamic drag in the range of transonic speeds (about M=1, more or less). This resistance grows due to a sharp increase in one of its components - wave resistance. The same one that we did not take into account when considering flights at subsonic speeds.

For the formation of numerous shock waves (or shock waves) during the deceleration of a supersonic flow, as I said above, energy is spent, and it is taken from the kinetic energy of the aircraft. That is, the plane simply slows down (and very noticeably!). That's what it is wave resistance.

Moreover, shock waves, due to the sharp deceleration of the flow in them, contribute to the separation of the boundary layer after itself and its transformation from laminar to turbulent. This further increases the aerodynamic drag.

Airfoil flow at various M numbers. Shocks, local supersonic zones, turbulent zones.

Second. Due to the appearance of local supersonic zones on the wing profile and their further shift to the tail section of the profile with an increase in the flow velocity and, thereby, a change in the pressure distribution pattern on the profile, the point of application of aerodynamic forces (pressure center) also shifts to the trailing edge. As a result, there appears diving moment relative to the center of mass of the aircraft, causing it to lower its nose.

What does all this result in ... Due to the rather sharp increase in aerodynamic drag, the aircraft needs a significant engine power reserve to overcome the transonic zone and reach, so to speak, real supersonic.

A sharp increase in aerodynamic drag on transonic (wave crisis) due to an increase in wave drag. Cd is the drag coefficient.

Further. Due to the occurrence of a diving moment, difficulties arise in pitch control. In addition, due to the disorder and unevenness of the processes associated with the emergence of local supersonic zones with shock waves, too difficult to manage. For example, on a roll, due to different processes on the left and right planes.

Yes, plus the occurrence of vibrations, often quite strong due to local turbulence.

In general, a complete set of pleasures, which bears the name wave crisis. But, true, they all take place (there were, specific :-)) when using typical subsonic aircraft (with a thick profile of a straight wing) in order to achieve supersonic speeds.

Initially, when there was not enough knowledge yet, and the processes of reaching supersonics were not comprehensively studied, this very set was considered almost fatally insurmountable and was called sound barrier(or supersonic barrier, if you want to:-)).

When trying to overcome the speed of sound on conventional piston aircraft, there were many tragic cases. Strong vibration sometimes led to the destruction of the structure. The aircraft did not have enough power for the required acceleration. In level flight, it was impossible due to an effect of the same nature as wave crisis.

Therefore, a dive was used for acceleration. But it could very well be fatal. The dive moment that appeared during a wave crisis made the dive protracted, and sometimes there was no way out of it. Indeed, in order to restore control and eliminate the wave crisis, it was necessary to extinguish the speed. But to do this in a dive is extremely difficult (if not impossible).

Dragging into a dive from level flight is considered one of the main causes of the disaster in the USSR on May 27, 1943 of the famous experimental BI-1 fighter with a liquid rocket engine. Tests were carried out for the maximum flight speed, and according to the designers, the speed achieved was more than 800 km / h. Then there was a delay in the peak, from which the plane did not come out.

Experimental fighter BI-1.

In our time wave crisis already well enough studied and overcome sound barrier(if it is required :-)) is not difficult. On aircraft that are designed to fly at sufficiently high speeds, certain design solutions and restrictions are applied to facilitate their flight operation.

As is known, the wave crisis begins at numbers M close to unity. Therefore, almost all jet subsonic liners (passenger, in particular) have a flight limitation on the number M. Usually it is in the region of 0.8-0.9M. The pilot is instructed to follow this. In addition, on many aircraft, when the limit level is reached, after which the airspeed must be reduced.

Almost all aircraft flying at speeds of at least 800 km/h and above have swept wing(at least on the leading edge :-)). It allows you to push back the start of the offensive wave crisis up to speeds corresponding to M=0.85-0.95.

Arrow wing. Fundamental action.

The reason for this effect can be explained quite simply. On a straight wing, an air flow with a speed V runs almost at a right angle, and on a swept wing (sweep angle χ) at a certain slip angle β. The velocity V can be vectorially decomposed into two streams: Vτ and Vn .

The flow Vτ does not affect the pressure distribution on the wing, but it does the flow Vn, which determines the carrying properties of the wing. And it is obviously less in magnitude of the total flow V. Therefore, on the swept wing, the onset of a wave crisis and the growth wave resistance occurs noticeably later than on a straight wing at the same freestream velocity.

Experimental fighter E-2A (the predecessor of the MIG-21). Typical swept wing.

One of the modifications of the swept wing was the wing with supercritical profile(mentioned him). It also allows you to move the beginning of the wave crisis at high speeds, in addition, it allows you to increase efficiency, which is important for passenger liners.

SuperJet 100. Supercritical swept wing.

If the aircraft is intended to transit sound barrier(passing and wave crisis too :-)) and supersonic flight, then it usually always differs in certain design features. In particular, it usually has thin profile of the wing and plumage with sharp edges(including diamond-shaped or triangular) and a certain shape of the wing in plan (for example, triangular or trapezoidal with an influx, etc.).

Supersonic MIG-21. Follower E-2A. A typical triangular wing.

MIG-25. An example of a typical aircraft designed for supersonic flight. Thin profiles of the wing and plumage, sharp edges. Trapezoidal wing. profile

Passing the notorious sound barrier, that is, such aircraft carry out the transition to supersonic speed on afterburning engine operation due to the increase in aerodynamic resistance, and, of course, in order to quickly slip through the zone wave crisis. And the very moment of this transition is most often not felt in any way (I repeat :-)) neither by the pilot (he can only reduce the sound pressure level in the cockpit), nor by an outside observer, if, of course, he could observe this :-).

However, here it is worth mentioning one more misconception, connected with outside observers. Surely many have seen this kind of photographs, the captions under which say that this is the moment of overcoming the plane sound barrier so to speak, visually.

Prandtl-Gloert effect. Not related to passing the sound barrier.

Firstly, we already know that there is no sound barrier, as such, and the transition to supersonic itself is not accompanied by anything so extraordinary (including clap or explosion).

Secondly. What we saw in the photo is the so-called Prandtl-Gloert effect. I already wrote about him. It is in no way directly related to the transition to supersonic. It's just that at high speeds (subsonic, by the way :-)) the plane, moving a certain mass of air in front of it, creates some rarefaction area. Immediately after the passage, this area begins to fill with air from the nearby space with natural an increase in volume and a sharp drop in temperature.

If air humidity is sufficient and the temperature falls below the dew point of the ambient air, then moisture condensation from water vapor in the form of fog, which we see. As soon as conditions are restored to the original, this fog immediately disappears. This whole process is rather short.

Such a process at high transonic speeds can be facilitated by local surges I, sometimes helping to form something similar to a gentle cone around the aircraft.

High speeds favor this phenomenon, however, if the air humidity is sufficient, then it can occur (and occurs) at rather low speeds. For example, above the surface of water bodies. By the way, most of the beautiful photos of this nature were taken from the aircraft carrier, that is, in fairly humid air.

That's how it works. The shots, of course, are cool, the spectacle is spectacular :-), but this is not at all what it is most often called. nothing to do with it (and supersonic barrier Same:-)). And this is good, I think, otherwise the observers who take this kind of photo and video might not be good. shock wave, do you know:-)…

In conclusion, one video (I have already used it before), the authors of which show the effect of a shock wave from an aircraft flying at low altitude at supersonic speed. There is, of course, a certain exaggeration there :-), but the general principle is clear. And again, it's amazing :-)

And that's all for today. Thank you for reading the article to the end :-). Until we meet again…

Photos are clickable.

Many people are afraid of flying. Psychologists say that there is even such a thing as "aerophobia". Patients with this diagnosis experience real horror at the mere thought of taking to the air. The strongest negative emotions are caused by air pockets and turbulence. Such moments are unpleasant even for those who do not experience fear of flying. However, the pilots claim that in fact this is quite a common natural phenomenon that can be explained in scientific language, and it will not bring any trouble to the passengers of the airliner. Today we decided to tell you what an air pocket really is, and whether it is worth being afraid of.

Term Explanation

It is quite difficult for an ordinary person to understand what an air pocket actually is. Everyone understands that there are no highways and pavements in the sky, and therefore there can be no holes. For example, when it comes to driving a car, it is absolutely clear to anyone that there may be an obstacle or a hole on the road that an experienced driver can cut. But what if you get into an air pocket? Can it be bypassed? And how dangerous is she? We will answer all these questions in the following sections of the article. But let's understand this difficult topic gradually.

Scientists have long known that air currents are not uniform. They have different directions, temperatures and even densities. All this affects airliners following certain routes. In the case when the plane encounters streams of lower temperature on its way, a complete illusion of a short-term fall is created. Then we usually say that the ship has fallen into an air pocket. However, in reality, this is just an illusion that can be easily explained with the help of modern science.

Downstream and Upstream

To understand how air pockets form, it is necessary to have a complete understanding of the movement of air currents. According to the laws of physics, heated air always rises, and cooled air falls down. Warm currents are called ascending, they always tend upward. And cold air is considered to be descending, and like a funnel it pulls down everything that comes in its way.

It is because of the movement of these flows that air pockets so unloved by passengers are formed during the flight. They make travelers experience very unpleasant sensations that many cannot forget for a long time.

The principle of the formation of air pockets

Despite the fact that the modern aircraft industry has long equipped its new liners with an abundance of technological innovations designed to make flying comfortable and safe, so far no one has managed to save passengers from the discomfort caused by descending air masses. So, the plane got into an air pocket. What happens to him at this moment?

Even when flying in good weather conditions, an airliner can encounter cold air. Since it is descending, it begins to significantly slow down the rate of ascent of the aircraft. It is noteworthy that in a straight line it goes with the same indicators, but it loses a little height. This usually only lasts for a few moments.

The airliner then meets the updraft, which begins to push it upwards. This allows the aircraft to return to its previous altitude and continue flying normally.

Feelings of passengers

For those who have never been in air pockets, it is quite difficult to understand how the passengers of the aircraft feel. Usually people complain that they experience stomach cramps, nausea rising to the throat, and even, lasting a fraction of a second, weightlessness. All this is accompanied by the illusion of falling, which is perceived as realistic as possible. The totality of sensations leads to uncontrollable fear, which in the future does not allow most people to calmly endure flights and causes aerophobia.

Is it worth it to panic?

Unfortunately, not a single highly professional pilot will be able to get past the air pocket. It is impossible to fly around it, and even the brand and class of the aircraft will not be able to protect passengers from unpleasant experiences.

Pilots claim that the moment the plane hits the downdraft, it loses control for a while. But you should not panic because of this, such a situation lasts no more than a few seconds and, apart from unpleasant sensations, does not threaten travelers with anything.

However, you need to know that in the air pocket the airliner is under serious pressure. At this point, the plane hits "chatter" or turbulence, which, in turn, adds to the frightened passengers' discomfort.

Briefly about turbulence

This phenomenon gives travelers a lot of inconvenience, but in fact it is not dangerous and cannot lead to an airliner crash. It is believed that the loads on an airplane during turbulence are no higher than on a car that is moving on a rough road.

A turbulence zone is formed when air flows with different speeds meet. At this point, vortex waves are formed, which cause "chatter". It is noteworthy that turbulence occurs regularly on some routes. For example, when flying over mountains, the plane always shakes. Such zones are quite long, and the “chatter” can last from several minutes to half an hour.

Causes of turbulence

We have already talked about the most common reason for the appearance of "bumpiness", but, in addition to this, other factors can also cause it. For example, an air liner flying in front often contributes to the formation of vortices, and these, in turn, form a zone of turbulence.

Near the surface of the earth, the air warms up unevenly, which is why vortex flows are created, which cause turbulence.

It is noteworthy that pilots compare flying in the clouds to highway traffic with potholes and potholes. Therefore, in cloudy weather, passengers most often experience all the "charms" of a flight in a shaking plane.

The dangers of turbulence

Most passengers seriously believe that turbulence can break the cabin's airtightness and lead to a crash. But in fact, this is the safest phenomenon of all possible. The history of air transportation does not know a case when getting into a "bump" would lead to fatal consequences.

Aircraft designers always put a certain margin of safety into the body of the aircraft, which will quite calmly withstand both turbulence and thunderstorms. Of course, such a phenomenon causes anxiety, unpleasant emotions and even panic among passengers. But in fact, you just need to calmly wait out this moment, not succumbing to your own fear.

How to behave during the flight: a few simple rules

If you are very afraid of flying, and thoughts about air pockets and turbulence make you feel terrified, then try to follow a number of simple rules that will greatly alleviate your condition:

• do not drink alcohol during the flight, it will only aggravate unpleasant emotions;
• try to drink water with lemon, it will relieve attacks of nausea when it enters the air pockets;
• before the trip, set yourself up in a positive way, otherwise you will always be tormented by forebodings and negative emotions;
• be sure to fasten your seat belts, passengers may be injured during the passage of the turbulence zone;
• if you are very afraid of flying, then choose larger aircraft models that are less sensitive to all sorts of shaking.

We hope that after reading our article, your fear of flying will become less acute, and your next air travel will be easy and enjoyable.