Today we will dispel the fears of air passengers from the take-off of a modern airliner.

I was inspired to write an opus now by one of the readers, who sent links to a couple of takeoffs from Kurumoch Airport (Samara), filmed by curious passengers from the cabin.

These videos have attracted comments. Well, here they are:

Comments on it:

And comments:

Both cases are united by one sign - the pilots "immediately went to take off!"

Nightmare, isn't it?!

Let's find out!

Experienced passengers probably remember the ritual that is repeated in almost every takeoff of a Soviet airliner - the plane stops at the beginning of the runway, then stops for a while - the pilots let the passengers pray .. but why hide - they themselves "prayed" at that time - that's what they jokingly call reading the checklist. After that, the engines abruptly begin to roar strongly, the plane trembles, the passengers cross themselves ... the pilot releases the brakes and an unknown force begins to press the hushed passengers into their seats. Everything is shaking, the shelves open, something falls on the conductors...

And suddenly, quite by accident, of course, the plane takes off. It gets a little quieter, you can take a breath ... But suddenly the plane starts to fall down!

At the last moment, the pilots, as a rule, "level the liner", after that the turbines "turn off" a couple of times in the climb, and then everything becomes normal. Stewardesses with stone faces carry juices, water, for those who prayed badly - an oxygen mask. And then the main thing begins, for the sake of which passengers fly - they deliver food.

Missed nothing? It seems that I read such reviews about flights more than once on non-core forums.

Let's figure it out.

Right away, let's dot the e about the stop of the liner on the runway before takeoff. What should pilots do anyway - stop or not?

The answer is - and so and so right. Modern takeoff technique recommends NOT stopping on the runway unless there is a good reason for doing so. Under such reasons may be hidden:

• a) The dispatcher is still thinking whether to let you out or hold you a little longer
• b) The strip has a limited length.

On point A, I think everything is clear.

On point B, I will say the following - if the runway (strip) is really very short, and the plane is loaded so that only the mass passes for this length - in this case it makes sense to save a few tens of meters and put the engine in high mode, keeping the plane on the brakes . Or the runway is just, well, very unusually short, even if the plane is light. In this case, the pilot will also do this "just in case".

For example, we use such a takeoff in Chambery. There, the runway is only two kilometers, and there are mountains ahead. I want to get off the ground as quickly as possible and rush higher. And usually the mass there is close to the maximum possible for take-off conditions.

In the overwhelming majority of cases, if the dispatcher allowed us to take off at the same time as the runway was taken, we will not stop. We will taxi to the center line (and, perhaps, with acceleration), we will make sure that the aircraft is in a stable rectilinear movement, and after that we will “let it go”.

How about "pray"? After all, it is written above about a certain "map of control checks!"

On B737, it is customary to read it out before obtaining permission to occupy the lane. And certainly before obtaining permission to take off. So when I get clearance to take off at the same time as clearance to enter the runway, I am ready to take off and I am not in any hurry, as it may seem to the passenger in the cabin. I have everything ready.

So why do it anyway? Why not stand up?

Obvious pluses - increase in throughput of the airport. The less time each individual aircraft occupies the runway, the more takeoff and landing operations can be performed from it.

The second is fuel economy.

The third is safety. Strange as it sounds, it reduces the risk of foreign objects (into the engine) and engine surge (read "failure") when taking off with a strong tailwind.

Why do pilots turn their nose up so sharply after takeoff? Here, on Soviet technology, they did it smoothly, slowly ... After all, the hour is not even, they will drop what for!

There is naked aerodynamics and a take-off technique. Foreign cars, as a rule, take off with a very small angle of deflection of the wing mechanization (those funny things that especially get out of the wing on landing, and a little on takeoff). This provides many benefits:

• a) Increasing angle of set
• b) consequence from point A: the noise on the ground is reduced,
• c) and further - the chances of not flying into obstacles in the event of an engine failure increase

Yes, modern airliners have such powerful engines that all normal climb gradients are achieved with reduced thrust (it will still be enough if the engine is lost), but in some situations, Mr. Boeing strongly recommends taking off at the maximum possible thrust. If the plane is light - it turns out just a cool attraction "Rocket".

Yes, this creates some discomfort for passengers (who like to fly with their legs up) - but it is absolutely safe and will not last very long.

"Almost Fell After Takeoff"

Above, I wrote that the plane after takeoff suddenly "begins to fall down!" This was especially well felt on the Tu-154, which took off with a straining attitude with a rather large flap angle, and then gradually removed them to the zero position. When the flaps are retracted, the aircraft loses part of the increase in lift (if you remove it too quickly, you can actually lose altitude - this is true, but for this you need to be a completely inept pilot, and both pilots must be inept), so it seems in the cabin, that the plane began to fall.

In fact, he can continue to climb at this time. It's just that the angle becomes flatter and at this transitional moment it seems to a person that he is flying down. This is how man is already made.

"The turbines were turned off a couple of times"

Oh, this is the most frequent incident in the stories of passengers! Only "the pilot only got to the airfield on the fifth attempt" can compete with this. This was most typical for the Tu-154 and Tu-134, that is, on aircraft with engines located far in the tail - they are almost inaudible in the cabin, unless they are operating at an increased mode.

The noise is just the same and a snag. Everything is primitive to disgrace. In climb, the engines operate at a very high rate. The higher the engine operating mode, the louder it is heard. But sometimes we, the pilots, have to obey the dispatcher's commands and stop climbing - for example, in order to pass (at a safe distance, of course) with another aircraft. We smoothly transfer the aircraft to level flight, and in order not to turn into a supersonic airliner (after all, engines operating in the set mode create very high thrust), we have to clean up the mode. The cabin is much quieter.

Starts from the moment you start moving along the runway for the takeoff run and ends at the height of the transition.

Takeoff is considered one of the most difficult and dangerous stages of flight: during takeoff, engines operating under conditions of maximum thermal and mechanical loading may fail, the aircraft (relative to other phases of flight) is filled with maximum fuel, and the flight altitude is still low. The biggest disaster in the history of aviation occurred on takeoff.

Specific take-off procedures for each type of aircraft are described in the aircraft flight manual. Adjustments may be made by output circuits, special conditions (e.g. noise reduction regulations), however, there are some general rules.

For acceleration, the engines are usually set to takeoff. This is an emergency mode, the duration of the flight on it is limited to a few minutes. Sometimes (if the length of the strip allows) during takeoff, the nominal mode is acceptable.

Before each takeoff, the navigator calculates the decision speed (V 1) up to which the takeoff can be safely terminated and the aircraft will stop within the runway. V 1 depends on many factors, such as: the length of the runway, its condition, coverage, weather conditions (wind, temperature), aircraft loading, balance, and others. If the failure occurred at a speed greater than V 1 , the only solution will continue to take off and then land. Most aircraft types civil aviation designed in such a way that, even if one of the engines fails on takeoff, the power of the others will be enough to, after accelerating the car to a safe speed, rise to the minimum height from which you can enter the glide path and land the aircraft.

Before takeoff, the pilot extends the flaps and slats to the calculated position to increase lifting force, and at the same time minimally hinder the acceleration of the aircraft. Then, after waiting for the dispatcher's permission, the pilot sets the takeoff mode to the engines and releases the wheel brakes. The main task of the pilot at this time is to keep the car strictly along the axis, preventing its lateral displacement. This is especially important in windy conditions. Up to a certain speed, the aerodynamic rudder is ineffective and taxiing occurs by braking one of the main landing gear. After reaching - the rudder. The nose landing gear on the takeoff run is usually locked for turning (the aircraft turns with its help while taxiing). As soon as takeoff speed is reached, the pilot smoothly takes over the helm, increasing the angle of attack. The nose of the aircraft rises ("Lift"), and then the entire aircraft lifts off the ground.

Immediately after takeoff, to reduce drag (at a height of at least 5 meters), the landing gear is removed, and (if any) exhaust lights, then the wing mechanization is gradually removed. Gradual cleaning is due to the need to slowly reduce the lift of the wing. With the rapid removal of mechanization, the aircraft can give a dangerous drawdown. In winter, when the plane flies into relatively warm air layers, where the efficiency of the engines drops, the drawdown can be especially deep. Approximately according to this scenario, the Ruslan disaster occurred in Irkutsk.

Once the transition height is reached, the pilot sets the standard pressure to 760 mmHg. Airports are located at different heights, and air transport is controlled in a single system, therefore, at the transition altitude, the pilot must switch from the height reference system from the runway level (or sea level) to the flight level (conditional height). After that, the take-off stage is considered completed, and the next flight stage begins: climb.

There are several types of aircraft takeoff.

• Takeoff with brakes. The engines are brought to the maximum thrust mode, at which the aircraft is held on the brakes; after the engines have reached the set mode, the brakes are released, and the run begins.
• Takeoff with a short stop on the runway. The crew does not wait until the engines reach the required mode, but immediately starts the takeoff run (the engines must reach the required power up to a certain speed). In this case, the length of the run increases.
• Takeoff without stopping rolling start), "on the go". The engines enter the desired mode in the process of taxiing out from the taxiway to the runway, it is used at high intensity of flights at the airfield.
• Takeoff with the use of special means. Most often, this is a takeoff from the deck of an aircraft carrier in conditions of a limited runway length. In such cases, a short takeoff is compensated by springboards, ejection devices, additional solid propellant rocket engines, automatic chassis wheel holders, etc.
• Takeoff aircraft with vertical or short takeoff. For example, Yak-38.
• Takeoff from the surface of the water.

Most passengers who use air transport to travel have fears associated with the takeoff of the aircraft. Today we finally dispel these fears.

I started writing this article because of a message from one of the readers, who provided me with a link to several takeoffs of airliners from Kurumoch Airport, which is in the city of Samara. In the video I received, a very curious passenger is filming from the plane.

Now we will try to figure it out!

Experienced passengers who travel by air quite often are aware of the old tradition that was introduced when flying on domestic aircraft. Before taking off, entering the runway, the plane made a stop for a few minutes, as if the pilots were giving the passengers the opportunity to pray. At the same time, the pilots of the liner also prayed, as they called this time, during which they studied the flight map and determined the checkpoints on the route. After this time, the plane actively rushed along the runway, while there was a roar and the whole apparatus was trembling. At this moment, like it or not, you will begin to be baptized. After that, the pilots released the brakes, which pressed the passengers even more into their seats and terrified them. With all this, shelves with luggage often began to come off, and something fell on the flight attendants.

As the plane takes off, video from the cockpit.

When taking off, it becomes a little quieter and calmer, but after taking off, the plane gradually begins to fall down!

Nevertheless, the pilots manage to level the device, the engines can also fail a couple of times when climbing the required height, and only then everything becomes normal. Flight attendants with indifferent faces offer drinks, and those who pray poorly are offered an oxygen mask. But only then comes the moment for which they use air Transport passengers - food is being delivered.

Like everything is indicated? This is the impression a person should have after reading reviews from non-core forums.

Need to figure it out.

As they say, let's dot the "and" about the reasons for stopping the aircraft on the runway before taking off directly. Is this moment necessary before takeoff or is it a whim of the pilots?

In this case, it must be said that both takeoff options are correct. Modern takeoff training teaches that stopping before takeoff is optional, but may be done if it is absolutely necessary. These needs may be:

• When the controller thinks, release the plane or hold it back a little in order to take off safely.
• With limited runway length.

With the first reason, I think everyone understands.

As for the second reason with a limited length of the runway, a stop is necessary here in case of an overload of the aircraft. The weight may be close enough to take off from that length. To do this, every meter of the strip is saved, and stopping allows you to bring the engine speed to higher operating modes, while the car is kept on the brakes. Very often, this procedure is carried out even by pilots on light vehicles, as they say, just in case.

Also, a similar separation is possible in a difficult geographical situation, for example, takeoff from Chambéry. It is necessary to carry out a stop and accelerate the engines, which will help to carry out a quick separation from the runway, since a mountain range begins beyond its end. In addition, almost all devices are heavy.

Nevertheless, in most cases, with the permission of the dispatcher and the normal length of the strip, the stop is not carried out. After the taxiway, the liners do not stop, but immediately begin to take off, before making sure that they are moving in a straight line, the pilots will only add engine speed.
Stop!
But what about prayer? After all, at first it was about a certain check of control points and the study of a flight map.

It is customary not to read the B737 until permission is received from the controller to occupy the runway, and even more so until it is received for the takeoff itself. That is why, when I get clearance to take off and take off at the same time, I am absolutely ready to take off. It only seems to the passengers that I am in a hurry, but this is not at all the case, since I am already ready.

There are also advantages in taking off without stopping:

• First of all, non-stop takeoff allows the airport to increase the capacity of aircraft. This is explained very easily: the less time the plane spends on the runway, the more liners will be able to fly or receive the airport.
• Also, non-stop takeoff allows you to save fuel, since there is no stop and acceleration of engines, which burns out a lot of fuel.
• The third advantage is security, at first glance you might think that this is a strange advantage. Still, the less time an aircraft with working engines is on the runway, the less likely it is for foreign objects to get into the turbines, which can lead to surge and engine failure.

Let's fly further!

Why do pilots lift up the nose of the car during takeoff? With the take-off of domestic technology, this process was done slowly and more smoothly ... Such a take-off can lead to an accident!

The reason for everything is the usual aerodynamics and the implementation of take-off technology. Foreign-made devices, mainly during take-off, weakly deflect the entire mechanism of the wings. In turn, this provides the following benefits:

• The climb angle becomes larger.
• Due to the large lift-off angle, the noise effect on the surrounding area is significantly reduced.
• It also allows you to encounter obstacles when one of the engines fails.

Modern passenger airliners are very powerful engines that even if one of them fails, a safe landing can be made. Nevertheless, in some situations it is recommended to turn on the full thrust of the engines, with a low load on the machine, this can turn it into a rocket.

The maximum thrust of the engines provides some discomfort to passengers in the cabin, of course, this is the case when you do not particularly like to fly with your legs up. But this position during takeoff does not last long.

“Almost fell after takeoff”

Earlier in the article, I wrote that after takeoff and takeoff, the plane, as it were, begins to fall down. A similar situation is very noticeable when flying on a Tu-154 aircraft, it takes off rather hard at a large flap opening angle, after which they become in a state of horizontal flight. When you move the flap position, you feel a decrease in altitude, as the nose of the car drops. It should be noted that in the case of a very fast closing of the flaps, the plane can really lose altitude, but for this you need to be a completely inexperienced pilot, especially since there are two of them in the cockpit.

Also, the feeling of the device falling over is also noticeable during the change of the climb angle to a more gentle one, but these are only sensations, in reality the plane is controlled and does not fall.

“During the flight, the engine turbines were turned off several times”

It is about such situations that passengers of aircraft most often write about. With these statements, only stories about how the pilots were able to land the plane on the runway only on the fifth attempt can compete for the championship. Most of these stories are about such liners as the Tu-134 or Tu-154. In them, indeed, the engines are located in the tail section of the apparatus and they are practically inaudible in the passenger compartment, except for situations when they operate at maximum speed.

It is in the noise from the engines that the snag of the supposedly “turning off the engines” is hidden. In fact, everything is very simple and clear. When taking off and climbing, aircraft engines really operate at elevated modes, which is accompanied by a high sound effect. Often, pilots receive commands from controllers to stop lifting the car in order to pass other aircraft in the air. In this case, the liner is transferred to a horizontal flight mode, in order not to become a supersonic aircraft, it is necessary to reduce the thrust of the engines. At the same time, the noise level in the cabin is reduced, due to this, passengers think that the engines are turned off.

The stronger the headwind, the higher the altitude the plane will reach at the time of takeoff. This increase in altitude is due to the action of a headwind reducing the aircraft's ground speed.

Why does an airplane take off against the wind?

Before takeoff aircraft must be turned into the wind. At the same time, there should be a sufficiently large space in front of him for the run-up, from which each take-off begins.

The takeoff run is necessary so that the aircraft can gain enough speed to lift off the ground.

When taking off with a tailwind, the aircraft needs more takeoff and acceleration speed. In addition, if the car rises into the air, surge can occur, which quite often leads to disastrous consequences.

Surging is a stall mode of operation of an aircraft engine, as well as a violation of the gas-dynamic stability of its operation, accompanied by pops in the air intake due to gas counterflow. Because of this, there is a sharp drop in thrust and a powerful vibration of the entire aircraft, and smoke appears from the engine exhaust. At the same time, the air flow flowing around the impeller blades then abruptly changes direction, as a result of which turbulent eddies appear inside the turbine.

The lift force of the wing depends on the square of the speed of the oncoming air flow. When taking off into the wind, the wind speed is added to the own speed of the aircraft itself. And the oncoming air flow allows you to increase the lift of the wing, due to which the minimum speed of the aircraft relative to the ground is reduced to keep itself in the air.

This situation is relevant not only for takeoff, but also for landing. After all, the lower the speed of the aircraft during landing, the safer and softer it can be.

Experienced pilots say that in no case should you rush during takeoff. After all, there have already been cases when excessive haste led to extremely sad consequences.

In addition to the fact that it is much easier for an airplane to take off against the wind, it also saves time and fuel. After all, an iron colossus consumes a huge amount of kerosene, and reducing the take-off time can save a lot of fuel.

Taking off with a side wind, especially a strong one, is extremely difficult. After all, the plane simply blows off the runway in gusts. And the pilots have to apply a number of specific combinations that will help level the car and get it into the air without any problems. Landing in such conditions is also quite difficult.

What to Consider

Before takeoff, pilots receive all the necessary information: both wind speed and direction, and many other special data that should help them make a correct and easy takeoff.

However, it happens that pilots on takeoff can make mistakes. Some of them are not even felt by the passengers. Others end very sadly.

Pilots, on the other hand, need to be very careful about the take-off procedure and be collected on the runway. In addition, modern aircraft are such that they can easily take off both against and downwind. Yes, and the side will not cause them any problems either.

A turbine is a machine in which a drum, propeller or wheel rotates under the influence of a jet of steam, gas or water and generates energy. The simplest turbines are water wheels and windmills.

Water turbines are used in power plants. They are built near dams and waterfalls. To start the turbine, a jet of water is brought to its blades and causes them to rotate. The turbine itself does not produce electrical energy. But a generator is supplied to it, which the turbine makes rotate, and which in turn generates electricity. Turbine blades can be made in the form of wheels or drums with blades along the edges. The bearing blades of some turbines are propeller-shaped.

Steam turbines are driven by a jet of steam. They are used to generate electricity, to rotate ship propellers, and to operate pumps. Gas turbines are powered by the exhaust gas generated after the combustion of fuel. The jet of hot gas is directed to the turbine and rotates its blades.

Thanks to the turbine in the engine, the filling of the cylinders with air is accelerated, which allows them to burn more fuel in them. Due to this, the engine power is noticeably increased.

The principle of operation of the turbine is quite simple. The device uses the energy of the exhaust gases, which enter under pressure into the turbine housing through the exhaust manifold. A compressor wheel is mounted on the turbine wheel shaft. It compresses the air as it rotates and delivers it to the intake manifold. Therefore, the greater the volume of gas passing through the turbine wheel, the faster it rotates.

A small turbine will spin faster than a large one for the same exhaust energy. However, it is a large constriction in the flow path of the exhaust gas. This causes a back pressure to form between the turbine and the combustion chamber. Back pressure is a side effect of using a turbine. Therefore, when choosing it, you should focus on the speed necessary to provide the desired response and boost pressure, while adhering to minimizing back pressure.