What is clear air turbulence, and what to do if a plane gets caught in it. A clear-sky disaster: how dangerous turbulence is. Engineering Sciences - Indicator Where clear air turbulence occurs most often

Cause of the plane incident Boeing 777 Aeroflot airline operating a flight Moscow - Bangkok. This was reported by the carrier's press service. The President of the Air Transport Infrastructure Development Fund, Honored Pilot of the USSR Oleg Smirnov, answered TASS questions about what this phenomenon is and what should passengers of an airplane caught in its zone do.

What is turbulence?

Turbulence is the chaotic movement of air masses having different densities and temperatures. Smirnov says there are several types of turbulence. During the flight, airliners very often pass through this zone during takeoff and landing, especially in summer. It is caused by the fact that warm air currents coming from the ground collide with cold ones. At this time, the plane may shake and panels may creak. But this turbulence is absolutely safe for passengers and the airliner - provided that travelers are sitting in their seats and wearing seat belts.

Turbulence at medium and high altitudes is extremely dangerous, according to Smirnov. It usually forms in cumulus and thunderstorm clouds. They are clearly visible - both visually and on radar. Both international and Russian flight safety regulations require controllers and pilots to avoid these areas. “It is strictly forbidden to enter powerful cumulus and thunderstorm clouds,” Smirnov said.

“Clear-sky turbulence” is distinguished by the fact that it occurs in an absolutely clean, cloudless space. It is invisible to the pilot's eye and is not detected by radar. Most often it occurs due to the jet stream - a strong wind that blows at a speed of about 300 kilometers per hour. Last year, there were 750 cases of planes getting into such turbulence around the world.

Yes. After encountering turbulence, the aircraft may reach supercritical angles of attack (that is, the air flow will blow over the aircraft's wing without creating lift), lose control and fall. Fortunately, pilots are trained to deal with this situation.

And what to do in case of “clear sky turbulence”?

Smirnov claims that the recipe is simple: if possible, remain seat belted throughout the entire flight (by the way, this is also recommended by the aviation safety instructions). If the flight attendant commands you to fasten your seat belts and clear the table, you should do this immediately. By the way, the pilots of the aircraft are fastened to the seat for the entire flight - right up to the end of taxiing. “This is inconvenient for some, but you can be sure that if you get into such a situation, you will remain in your seat and will not hit the ceiling of the plane,” said the honored pilot of the USSR.

In addition, Smirnov recommends, if possible, avoiding the use of heavy objects such as laptops during flight. If the aircraft encounters turbulence, the aircraft can easily be torn out of your hands and can cause significant injury to you or other passengers.

All these restrictions will have to be observed until scientists learn to recognize “clear-air turbulence.” According to Oleg Smirnov, developments in this direction have been going on for a long time: “They are working on such a device, and, I hope, it will soon be presented and aircraft will be equipped with it.”

The moments that the passengers of the Moscow-Bangkok flight had to endure can be called, without exaggeration, terrible. The plane was trapped in what pilots call “clear air turbulence.” Fractures, injuries - people had the feeling that the plane began to fall. 27 people were injured, 15 of them remain in Bangkok hospitals.

The first minutes after the shaking. There is a terrible picture in the cabin of the plane. Bloodied passengers lie in the aisles and sit at emergency exits. Many are asked not to get up - it is unknown how serious the injuries are. As it turns out later, there were fractures and severe bruises.

“On one side there was a woman lying, moaning, she was in great pain. And the man moaned. He was apparently in doubly pain. The girl, when it was all over, walked around the salon, she had a black eye, her cheek was all torn. There were many such people who suffered greatly. Almost no one was wearing a seat belt or had time to do so,” says passenger Elena Tregubets.

The plane had not yet begun its descent, so the “Fasten seat belts” sign was not on. People calmly walked around the cabin - warming up in the aisles after a nine-hour flight. The Moscow-Bangkok flight was coming to an end. 40 minutes before landing - sharp shocks. The 300-ton Boeing 777 fell almost 250 meters into the air pocket.

“We were rocked two or three times. And somehow I immediately intuitively began to buckle up. And literally a couple of seconds, and it was as if we began to fall. And the passengers flew up to the ceiling, and with a roar they all fell down,” says Elena Tregubets.

Doctors met the plane at the airport. In total there were 313 people on board. 27 - among them both Russians and foreigners - were immediately sent to a local hospital. There, some victims had to undergo operations. Embassy staff and a translator were sent to the hospital to help the Russians.

The weather in the skies over Thailand did not promise anything bad. According to experts, the plane encountered so-called clear-air turbulence.

“It does not appear in the clouds, but in a clear sky with good visibility. And it is not recorded by instruments. The main danger is that the crew has no way to warn passengers about the need to buckle up. This situation is extremely dangerous for passengers who do not fasten their seat belts,” Aeroflot explained.

Such chatter also happens in the skies over Russia, but much weaker than in tropical latitudes.

“In tropical latitudes it is more developed and is characterized by very large gradients, that is, power and unpredictability. It was impossible to avoid this. Although we must keep our eyes open,” the commander of the aviation squadron, pilot Sergei Matrosov, comments on the situation.

Ideally, you need to be buckled up for the entire flight, like the crew of this flight. Job description. At the helm was experienced pilot Alexander Ruzov, with over 23 thousand flight hours. Co-pilot Artem Unanov - more than 10 thousand flight hours. They took the car out of the turbulence zone and landed it in normal mode. According to them, the shaking intensified due to the actions of the autopilot.

“The autopilot was unable to react correctly in time, which is why the plane was thrown like that. Therefore, after hitting an air pocket, we turned off the autopilot and smoothly brought the plane into horizontal, level flight,” said Alexander Ruzov.

Travelers noted the work of the flight attendants. They provided assistance and did everything to avoid panic. Although they themselves got it pretty bad.

“It was clear from them that they were injured, they were also scratched, they were also not ready for this. They gave painkillers to those who were very seriously injured and applied tourniquets,” says Elena Tregubets.

Such cases are not uncommon in civil aviation. Every year, almost 750 such incidents are recorded around the world. 30 people were injured on an Etihad Airways flight from Abu Dhabi to Jakarta. And this is footage from the flight from Lima to Buenos Aires - even the crew members got it. But perhaps the loudest incident is in the skies over Hong Kong. In August 2013, two airliners entered the turbulence zone at once. One of the passengers then hit the plastic trim of the cabin with his head. More than fifty people were taken to hospitals.

Passengers on the Moscow-Bangkok flight continue to receive assistance in Thai clinics. Their lives are not in danger. A hotline has been opened for relatives - by calling +66904033645 you can find out all the latest information about the condition of the victims. Meanwhile, it became known that all victims will receive compensation. In addition, they will be paid for treatment, re-issuance of tickets and hotels.

At the same time, after landing, airport services checked the Boeing itself, which had fallen into an air pocket. No damage was found. The plane immediately flew back to Moscow.

Did you pay attention the other day to the news about the Moscow-Bangkok plane that got into turbulence?

About 40 minutes before landing, the plane hit an air pocket. In 15 seconds, the plane was first thrown 200 meters. And then it fell back the same meters. As a result, those who were not wearing seat belts were simply thrown out of their seats, thrown up, and then fell down.

According to some reports, 27 people were injured, including serious fractures. According to the news, 10 people have already been operated on in Bangkok.

Cause of incident - clear sky turbulence. The instruments on board the aircraft cannot predict its appearance. But why in a clear sky?!

As we know, air turbulence is a powerful disturbance of air flows, multidirectional movements of air masses up, down, and sideways. The speeds of gusts and currents reach colossal values. Ascending and descending currents rush a huge mass of air in different directions. An airplane caught in such a mess will be thrown like a chip in a stormy mudflow. The main reasons for such bumps are the heterogeneous composition of the atmosphere, which is affected by temperature, pressure, and humidity.

Very often, such up-down-sideways flows are formed not only in thunderclouds, but also above the boundaries - the junctions of various types of earth's surface: land-sea, steppe-forest, plain-mountains, etc. This is due to different degrees of heating of these surfaces and air masses above them, evaporation. So the cycle begins - the larger the area of ​​these adjacent surfaces and the temperature difference, the higher the turbulence above their boundary.

And more about clear skies:

You may believe it or not, but it is a fact (like the fact that the earth is round) that there are rivers, rivulets, and streams in the sky. Only the size of these rivers and streams is monstrous! Thousands of kilometers long, tens of kilometers high and hundreds of kilometers wide. The flow speed in these currents can reach half a thousand kilometers per hour!

And now imagine, you are riding a bicycle along a path between residential areas, whistling your favorite melody, suspecting nothing, and suddenly the houses end, and you jump out at speed around the corner, and there is a gusty wind! How will you feel? That's it!

If you know that there will be wind around the corner (and this can often be determined visually by dust, leaves, and debris rushing around the corner), then of course you will take action. Either don't go there, go around, or be prepared for the wind to blow!
So it is with “clear sky turbulence.” This phenomenon has long been known and easily explained and, alas, it is not uncommon! There are even signs and places where you are likely to run into it, but they are too unpredictable.

Where are you most likely to encounter this phenomenon?
Typically, this is the boundary of the air flow at the entrance and exit to and from the flow. But the trouble is that it is almost impossible to see this flow with a modern radar, but to feel its influence on yourself is even very...

05.07.2018, 12:50

Clear-sky turbulence is the most unpleasant and undesirable type of eddy drifts that appear unexpectedly in a cloudless space with excellent visibility. The plane finds itself between air currents that vary greatly in direction and speed, temperature and density. At this moment he seems to fall into a hole and begins to shake. The consequences of this can vary from passenger injuries to an aircraft crash.

This type of turbulence is very difficult to detect in advance - both visually and using radar or lidar, because it is impossible to see the low pressure area in the clear sky. However, in May 2018, Russian scientists announced that they had learned to predict clear-air turbulence using a special device that monitors the change in muons.

When charged particles enter the atmosphere, they interact with nitrogen and oxygen atoms, resulting in muons. Every minute, an average of 120 of them fall per square meter of earth. Muons, passing through the atmosphere, lose their energy, and these losses depend on the density of the atmosphere. If a void or low-pressure area is encountered along the way, the muons lose less energy, which will be immediately detected. Thus, by the nature of changes in the muon flux, atmospheric processes can be monitored, described and predicted.

To detect these particles, scientists built a special device of gigantic size, called the “Muon Hodoscope” or “Hurricane”. The installation consists of large-area detectors (about 11 square meters), which register approximately two thousand muons every second. There are eight such modules, they are located on top of each other, which makes the installation a bit like a layer cake.

Eight recording planes of the installation form a picture, like an X-ray, which allows you to tell from which side the particle arrived in real time. Therefore, one complex is enough to see the sky within a radius of hundreds of kilometers and predict not only areas where clear-sky turbulence may occur, but also natural disasters such as snowfalls, storms, tornadoes and hurricanes, several hours before their manifestation, when all other methods are still powerless.

Today, scientists work closely with weather services and compare their forecasts, including those obtained by traditional methods. This is necessary to confirm the accuracy of the method, after which muon diagnostics can officially enter the service of meteorologists. We will not get rid of hurricanes, tornadoes and turbulence, at least “forewarned is forearmed.” Thanks to accurate forecasts, it is possible to restructure the flight path of an aircraft and prepare for natural disasters, which means avoiding disastrous consequences.

On May 1, 20 minutes before descent, an Aeroflot plane flying from Moscow to Bangkok entered a short-term zone of severe turbulence. Passengers who were not wearing seat belts received varying degrees of injuries, 25 of whom were hospitalized after landing. 15 Russians still remain in a Bangkok hospital, the Russian Embassy in Thailand reported.

Aeroflot: “Clear sky turbulence arose unexpectedly”

According to the commander of flight SU 270 Moscow - Bangkok, Alexander Ruzov, the overload lasted about 15 seconds, and after half a minute the airliner was brought onto the desired trajectory. This happened thanks to the competent actions of both the brigade and the crew, Ruzov noted in a telephone interview with one of the Russian TV channels. However, he expressed regret that passengers who were not wearing seat belts were injured.

The Aeroflot press service explained that the plane found itself in so-called “clear-sky turbulence.”

The Aeroflot press service explained that the plane found itself in so-called “clear-sky turbulence.” It does not appear in the clouds, but in a clear sky with good visibility, and the weather radar does not report its approach.

“Therefore, the crew does not have the opportunity to warn passengers about the need to return to their seats,” explained a representative of the airline. According to him, about 750 cases of clear-air turbulence are recorded per year in global civil aviation.

Aeroflot covered the costs of treating injured passengers. This was confirmed on Tuesday by the President of the All-Russian Union of Insurers, Igor Yurgens. According to him, the limit of the air carrier's liability insurance contract is enough to pay all compensation.

Aviation experts: “This is an amazing case that needs to be investigated”

However, some experts doubted that the Aeroflot airliner actually encountered “clear air turbulence.” For example, military meteorologist, reserve lieutenant colonel Evgeny Tishkovets, in an interview with NSN, said that phenomena such as clear-sky turbulence are very easy to predict.

“The crew should have been informed of what lay ahead. Either they were informed and they violated the instructions, or they were not notified of this.”

“This can be calculated in several ways, and using computer technology there are no problems at all. The crew should have been informed of what lay ahead. Either they were informed and they violated the instructions, or they were not notified about this,” Tishkovets said, noting that he personally examined the upper layers of the troposphere at that moment and did not see any clear-sky turbulence.

Aviation expert Oleg Panteleev, who heads the AviaPort agency, believes that the version of an aircraft malfunction in this case is not justified and is not motivated by anything.

“Unfortunately, cases where intense air currents throw or bring down planes several hundred meters are quite common in aviation. And there are a lot of victims from this all over the world. I believe that Aeroflot passengers got off lightly,” Panteleev shared his opinion with Public Control.

He recalled that all airlines, without exception, recommend their passengers to remain fastened - even if the “Fasten seat belts” sign is not lit. This minimizes the risks if the ship gets into a turbulence zone.

Honored Pilot of Russia Vadim Bazykin called the incident that happened with the Aeroflot plane surprising and requiring a thorough investigation. According to him, clear-sky turbulence can be predicted because it often occurs at the boundary of water and land - or in mountainous areas, where there is a difference in the temperatures of air masses: warm air goes up, cold air goes down, intersecting, they form a “chatter”.

Clear-sky turbulence can be predicted because it often occurs where there is a difference in air mass temperatures: warm air goes up, cold air goes down, intersecting, they form a “chatter”.

“We were not told such beautiful terms as clear-air turbulence, and were taught that if you see a bumpy situation, first of all turn off the autopilot, because, fighting with air currents, it only aggravates the situation, and it is not difficult to level the plane manually. The pilots of flight SU 270 Moscow - Bangkok turned off the autopilot after 15 seconds. Why it’s so late, we need to figure it out,” Bazykin told Public Control.

At the same time, the expert noted that there are several ways to determine the clear sky turbulence zone. For example, according to data from weather stations that mark different currents and wind directions, or according to ground speed.

The Investigative Committee of Russia is conducting a pre-investigation investigation into what happened on board a plane flying from Moscow to Bangkok on May 1. Based on its results, a decision will be made to initiate a criminal case.

In addition, the Federal Air Transport Agency will investigate the emergency.

Passengers: “This feeling when you fly from floor to ceiling and are not in control of the situation, but people, things and seats are flying nearby”

They are unlikely to be able to forget what the passengers of the ill-fated flight experienced.

“Three hours ago I was on a plane flying from Moscow to Bangkok. Suddenly we found ourselves in a zone of turbulence. It was so terrible that people were thrown around like crazy. There is blood everywhere, people with broken bones, noses, open fractures, children with head injuries, I could go on and on. Thank God we are all alive. I really hope that Aeroflot will do right by the victims. The airline staff did everything to help the people on board. As for the pilot, I can say he saved us all. Honestly, I have never been so scared,” Rostik Rusev, a passenger on flight SU 270 Moscow - Bangkok, wrote on Instagram. He attached a video to his post taken on the plane after passing through the turbulence zone.

“Unfortunately, my first news from Tay is this... We were on this flight and sat at the very back. And we saw all this horror with our own eyes... This feeling when you fly from floor to ceiling and have no control over the situation, and people, things and seats are flying nearby. By a lucky coincidence, we escaped with bruises. This is truly an accident; there were people with open fractures lying nearby. There is blood all over the tail of the plane. It can't be described in words. We're fine while we're in the hospital. Medicine in Thailand is at the highest level,” another passenger on the Aeroflot plane named Margarita said on her Instagram.