Climb trajectory TU 154. Speed, angle and vertical speed of gliding and descent

Yes, most likely so.
Well, or - agents of some absolutely fantastic level, literally having access to the President's plane ...

"According to Svetlana Petrenko, the official representative of the ICR, Sochi military investigators have already opened a criminal case on violation of flight rules. According to her, investigators are already seizing pre-flight documentation and interrogating flight managers, as well as technical staff who were involved in preparing the aircraft for departure and refueling.

Chairman of the Federation Council Committee on Defense and Security Viktor Ozerov has already completely ruled out the version of the terrorist attack. However, this version is not discounted.

There is reason to believe that on board the Tu-154 there was an explosion, - says aviation expert Sergey Krutousov. - In support of this terrible version, a large radius of debris dispersion - more than a kilometer - and the suddenness of what happened testify. The pilots did not have time to get in touch with the airport controllers.

However, most experts are inclined to the version of a technical problem, low-quality fuel or electronics failure. The crashed liner was 1983 release. Last time it was repaired in December 2014, and in September 2016 it underwent scheduled maintenance.

An audio recording of the allegedly last communication session between the crew of the Tu-154 aircraft of the RF Ministry of Defense and air traffic controllers has appeared on the Web. On the recording, the air traffic controller transmits weather data and other departure conditions. At the end of the audio recording, controllers try to contact the crew of the aircraft, but they no longer receive a response.

One of the probable causes of the TU-154 crash during climb could be the failure of the aircraft's hydraulic system, which led to the complete loss of the ability to control the machine by the crew. The reason for the failure of the hydraulic system of the aircraft could be a short circuit in one of the engines of the liner, a source in the GVSU told Life.

Life's source in the Interstate Aviation Committee (IAC) suggested that the Tu-154 could be killed by the so-called starter disease. According to him, after starting the engine, there were malfunctions of the air starter in one of the three engines of the aircraft. It was for this reason that on January 3, 1994, a Tu-154 crashed while taking off from Irkutsk airport, flying on the route Irkutsk - Moscow.

Then our experts found out that when the starter reached a dangerous speed, it was destroyed, and the damaged starter disk destroyed the fuel-oil communications of the engine and hydraulic system communications, after which the aircraft lost control, as a result of which it fell, - says the expert.

Another source of Life in the TFR does not exclude the version of low-quality fuel.

When taking off from the Adler airport, the Tu-154, most likely, could not gain the specified engine speeds, as a result of which it fell from a small height into the Black Sea. Refueling of the aircraft with low-quality fuel is considered as a priority version of the causes of engine failure, the source says.

According to him, experts have already taken samples of the fuel with which the Tu-154 was refueled at a military airfield in the Moscow region and in Adler. It cannot be ruled out that on takeoff due to problems with fuel, three aircraft engines could stop at once. Water could simply get into the fuel, which froze at negative temperatures, and ice formation blocked the passage of fuel through the filters.

Aeroflot pilot Yuri Litvinov, who once flew the Tu-154 for eight years and knows the Sochi airport well, is sure that the causes of the tragedy are not related to the weather and peculiarities air port, but rather with the failure of the liner systems.

The Tu-154 is a fairly reliable aircraft and very fast, but the pilots always called it a "strict aircraft". He does not forgive mistakes. It has outdated equipment that requires great skill from the pilot. Young pilots adapted to this aircraft for a very long time, Litvinov told Life. - Considering that they flew only one and a half kilometers from the coast, it looks more like a very serious technical failure.

As for the features of the place of departure, there is always a moderate wind shear at the Sochi airport, that is, multidirectional air flows on different heights Litvinov says.

This is always observed on the border of the sea and land, plus in Sochi there are mountains nearby. At the same time, temperature drops and pressure drops are observed. But the wind shear, the pilot emphasizes, could hardly lead to a tragedy, especially on takeoff.

Livtinov noted that the failure of the engines could also be related to the age of the aircraft: after all, the Tu-154 was 33 years old.

I think it is necessary to get rid of old aircraft and fly on new ones, - the expert sums up.

As the honored pilot of the Russian Federation Viktor Sazhenin, who flew at the helm of one hundred and fifty-fourth for eight years, told Life, the crash could have been caused by improper centering of the luggage. In the Tu-154, the distribution of baggage weight is extremely important so that the plane does not lead the tail down.

The aircraft has many features. The plane is long, cigar-shaped, has a narrow fuselage. It has a heavy tail because the engines are located there. Therefore, he has problems with centering. And in almost all the accidents that occurred with this aircraft, the fault went in this part, - Sazhenin told Life. - Ensemble flew here. It is possible that they had a lot of props, and it is not clear how it was loaded. And if you load the plane incorrectly, for example, everything, into the bow, then the centering may be disturbed.

Also, the plane could get into the updraft, after which it fell into a tailspin.

It can be assumed that when climbing, the car fell into an updraft and fell into a tailspin, says aviation expert Sergey Krutousov.

According to him, during the climb, the Tu-154 ended up on the border of two environments - water and land. This led to the car getting into the updraft, and at this angle of attack, the plane simply fell on the right or left wing and went into a tailspin.

The version of the error of the pilots is not excluded. While climbing, the pilots were unable to calculate the correct pitch angle.

When piloting in the helm mode, the main difficulty lies precisely in maintaining the correct speed, which is the key to stability when piloting and holding the aircraft in pitch at a climb speed of 500–550 km/h, says expert Sergey Krutousov.

The Tu-154 aircraft made its first flight in 1968 and was at one time the most massive and advanced civil aircraft until the 90s, says the former deputy minister civil aviation USSR Oleg Smirnov. This is a three-engine jet aircraft, which, according to NATO codification, is called Careless - "Carefree". Designed, depending on the modification, for 152-180 passengers, for medium-haul airlines. According to Smirnov, it was a very reliable aircraft for its time, which is confirmed by the number of aircraft produced - about a thousand. Unfortunately, they fell a lot. For all the time, 73 aircraft of this model crashed, the total number of deaths in crashes on the Tu-154 amounted to more than three thousand people. "

In total: a "strict" aircraft, does not forgive mistakes, serious problems with equipment, difficult conditions on the border of land and sea ... and - an explosion, a large spread of debris.

Pilots need to develop the habit of comparing attitude readings on the first turn, regardless of the navigator's report. The roll on the turn is set and controlled by the pilot; he reacts to the mismatch of artificial horizons - with his hands, in which he holds the helm.

Setting the pressure of 760 mm on altimeters in difficult conditions is made by the navigator, and this is the most best option when the captain is piloting. Experienced navigators, setting 760, translate the pressure value through 760, then return exactly to 760. This is necessary in order to reliably record on the MSRP that the crew did set 760; there were cases when, in a chatter, the hand did not bring the number 760 to division by half a millimeter, the MSRP did not record the pressure setting, and claims were made against the crew.

After setting the pressure and putting the aircraft on the exit course, the next task for the crew is: how much will we have time to gain on the way out?

In the first seconds after takeoff, the crew already has an idea about the balance and takeoff weight- whether they correspond to the calculation or differ from it. After cleaning the mechanization and accelerating the speed, it is already possible to get an idea of ​​the rate of climb of the machine. And you need to know the temperature at altitude in order to predict the rate of climb in these conditions.

If, according to all estimates, it turns out to gain a given level just right next to it, it is better to gain altitude, maintaining the speed with the autopilot "descent-ascent" handle - this is the best option that allows you to maintain vertical speed with minimal errors. The use of the ACS "Stab.V" mode in the set, especially when centering closer to the rear, leads to a buildup in pitch and a loss of average vertical speed; if at the same time the toggle switch is turned on "in chatter", the buildup sine wave will be even larger, because the speed tracking system becomes coarse and does not have time to respond to its small changes.

When approaching a given echelon, it is not necessary to set a vertical speed of 5 m / s for 200 meters and sneak up - this is ugly. For example, I keep the calculated vertical up to a difference of 100 m, then I decrease the pitch with the autopilot handle, guided not by the delayed variometer, but by the rate of movement of the numbers in the altimeter window. It is this pace that determines the change in vertical speed. As soon as the numbers in the window begin to stop, I, without looking at the variometer, again slightly deflect the autopilot handle to dial. With such small movements of the handle (wheel), you can easily and confidently achieve that the desired number appears and stops in the window; at this moment, making sure that there is no tendency to increase or decrease, I press the button "Stab. N". At the same time, the acutely responsive altitude tracking system sets the desired height with light twitches of the elevator, and as soon as the variometer needle reaches zero, you can turn on the toggle switch "in a chatter", rude the system - the elevator stops twitching.

If it becomes necessary to turn off the toggle switch "in a bumpy", it is necessary, in order to avoid jerking the elevator, first turn off the height stabilization mode. Practice has shown that an error accumulates there, and always in one direction, therefore, you need to remove from the "Stab.N" mode only forward, away from you, overcoming the tendency of the aircraft to turn up its nose.

If it is clear that we do not have time to take the given echelon to the exit, we must not be shy and ask the dispatcher to allow us to pass the point in the set. You should not spend kinetic energy on a dynamic set, and then hang in hot air and wait until the speed accelerates again.

Better let the dispatcher on the ground press the button and coordinate as much as possible. We must always remember who works for whom, and not be shy.

When changing the echelon to a higher one, there is often a doubt, "whether we scrape together." Experience has shown: if at 10600 the angle of attack is close to 4 o, with the calculated number "M", you can dial 11600. Even if the temperature overboard increases by 5 degrees during the climb, this will not interfere with the climb.

If a decision is made to bypass the storm front on horseback, it is necessary to start recruiting in advance in order to have time to recruit the highest echelon with a guarantee. It is very dangerous to overcome the remaining few hundred meters of altitude above the cloud tops in a dynamic set, losing speed. It is not possible to visually determine a sufficient set angle, and there is Great chance lose speed at the top of the cloud.

If there is a need to dial maximum height for a minimum period of time, then it is possible to use the kinetic energy of the aircraft, losing speed in the dynamic set. The best result is obtained if you start climbing 500 m below the given flight level. At 500 m, there is just enough margin of inertia with a loss of speed from 550 to 500 km / h. The vertical speed is best kept constant, about 15 m/s, and all the time to compare the rate of decrease in speed and increase in height.

Practice has shown that the most optimal climb occurs at a speed of 550 km / h. If there is not enough time to reach a given level with a headwind, there is no point in reducing the ground speed by reducing the indicated speed and climbing at a speed of 500. Reducing the vertical speed will negate the advantage in time, and, ultimately, you will lose.

If, after flying at a speed of 500 km / h, you need to accelerate the car for further gain, then acceleration should be carried out strictly in level flight. Acceleration with a slight climb, at 2-Sm/sec, will not save anything, and the aircraft accelerates very reluctantly, especially at altitude.

In order for the transition from the "Stab.V" mode to the "Stab.M" mode to take place without the jerk specified in the flight manual, you need to remove the "Stab.V" mode (away from yourself) with the wheel, and then take it a little with the same wheel on yourself and then press the "Stab.M" button; i.e.: it is better to make this jerk softer with your hands than to entrust it to a rough machine. Sometimes it is possible to switch from mode to mode completely inaudibly, and the overload does not change. The meaning of the operation is to remove the accumulated error, due to which, in fact, a jerk occurs.

At high vertical speeds, it is necessary to report on the occupation of a given intermediate level in advance, about 300 meters. If, as usual, the dispatcher has a hitch, a few seconds can be gained as follows. It is necessary to keep the speed not 550, but 540 300 meters before the flight level. While the dispatcher is determined, gives space, etc., you can slowly reduce the vertical speed, preventing the forward speed from accelerating too vigorously. Until the forward speed reaches 575, usually the controller finally sets a new level, and there is no need to remove the mode and transfer the machine to level flight.

When piloting in a climb in the helm mode, the main difficulty is maintaining the airspeed. In order to anticipate tendencies to change speed, it is necessary to Special attention keep the pitch angle constant. Aircraft feature - long length fuselage, and any change in the pitch angle creates a tendency of the spaced masses to increase this change. And although the stability-control system helps piloting, practice shows that success in maintaining speed, namely in climb, where speed constancy is the basis of piloting stability, is achieved by those pilots who know how to keep the pitch on an uncomfortable artificial horizon. On the contrary, those pilots who simply react to a change in speed swing the car in pitch.

Particular attention should be paid to the pitch on a sharp turn. It is necessary to make a rule for yourself: first look at the pitch, and then at the speed.

When maneuvering in climb, including when avoiding thunderstorms, one must constantly remember that airspeed can be easily and imperceptibly lost. In any case, at high echelons, the indicated speed should not be allowed to fall below 450 km / h, with the obligatory control of the reserve in terms of the angle of attack.

When flying in the spring-summer period, the outside air temperature is of particular importance. In summer, there is often a significant temperature deviation from the average values ​​​​in the direction of increase, and this phenomenon is of particular importance on high altitudes.

The question of what speed an aircraft develops during takeoff is of interest to many passengers. Non-professional opinions always differ - someone mistakenly assumes that the speed is always the same for all types of given aircraft, others correctly believe that it is different, but cannot explain why. Let's try to understand this topic.

Takeoff

Takeoff types

• From the brakes. The acceleration of the aircraft begins only after the engines have reached the set thrust mode, and until then the device is held in place with the help of brakes;
• A simple classic takeoff, involving a gradual increase in engine thrust while the aircraft is moving along the runway;
• Takeoff using assistive devices. Typical for aircraft carrying military service on aircraft carriers. limited distance runway offset by the use of springboards, ejection devices, or even additional rocket engines installed on the aircraft;
• Vertical takeoff. It is possible if the aircraft has engines with vertical thrust (for example, the domestic Yak-38). Such devices, like helicopters, first gain altitude from a standstill vertically or when accelerating from a very short distance, and then smoothly transition to horizontal flight.

Consider, as an example, the takeoff phase of a Boeing 737 turbofan aircraft.

Takeoff passenger Boeing 737

• The movement of the aircraft begins after the engine reaches about 800 rpm. The pilot gradually releases the brakes while keeping the control stick neutral. The run starts on three wheels;
• To start taking off from the ground, the Boeing must acquire a speed of about 180 km / h. When this value is reached, the pilot smoothly pulls the handle, which leads to the deflection of the flaps and, as a result, the rise of the nose of the device. Further, the plane accelerates already on two wheels;
• With the nose up on two wheels, the aircraft continues to accelerate until the speed reaches 220 km/h. When this value is reached, the aircraft lifts off the ground.

The plane disappeared from radar 2 minute flight. Not on the 7th, as some write, but on the 2nd. 7 minutes - this is the time from the moment the liner is allowed to move along taxiing and exit to the runway.
The Tu-154B takeoff speed is 230-260 km/h, depending on the load.
In the second or third minute of the flight, the aircraft leaves the Aerodrome for 6-8 km and rises to a height of 350-400 meters. This is exactly the distance that the headquarters of the Ministry of Defense and the Ministry of Emergency Situations presents to us.
The speed at that time is approximately 350-420 km / h, depending on the wind and the load of the liner.

Landing approach to Adler Airport is carried out from the sea side and planes take off in the same sea direction. Immediately after takeoff, the aircraft occupies the lower echelon, where it makes a turn to the North.

Small note:
Earlier, the plane was planned to land for refueling in Mozdok, from where it was already supposed to fly to Syria through Azerbaijan and Iraq, but weather conditions refueling was moved to Adler.

Imagine a picture:
Adler, night (gouge out your eye), the fully refueled liner begins to take off. Everything goes normally until the start of the turning point. The flaps are still out. Turning is accomplished by differentially moving the ailerons (to create roll), negative stabilisers, with some differentiation to assist the ailerons, and deflecting the rudder to the right.

If at this moment there is a failure in the operation of the mechanization of any of the controls, the pilots have, at best, 0.001 hours (0.06 minutes ( 3.6 seconds)) before hitting the water.
You can add 2-3 seconds to bring the liner from a climb with a roll to a steep dive with a roll to starboard before flipping "feet up".

This is THE BEST!

5-6 and even 7 seconds in the night sky over the sea NOT ENOUGH, in order for the crew to figure out what is happening in general. Not that something would be done to save the liner at such an altitude.

As you can see, blowing up something on the plane is not necessary. A banal technical malfunction is enough to ruin the plane and the people on board in a matter of seconds.
And an oil slick on the sea can just indicate a malfunction in the liner's hydraulic system.

Naturally, the explosion of one of the engines could lead to fatal malfunctions in the liner's control system. But for this, one of the engines had to LITERALLY explode. And since there are as many as 3 of them on the plane and the control of the plane is duplicated not only by hydraulics, but also by pure mechanics up to boosters, then even the explosion of one engine would hardly lead to such a disaster, as we see. The pilots would have had time to win back the roll simply by experience and motor skills (although the night over the sea is a poor help for clear orientation).

Scattering parts of the aircraft.

Here you need to understand a simple thing - 6-8 km. removal above the sea surface is an insignificant distance, from the point of view of acoustics. What would the airliner be torn to pieces so that they were ..., yes, at least 2 km from the point of explosion - this is necessary VERY powerful charge. Do not forget - the height was only 350-400 meters. This explosion would not only shatter the aircraft, but also shatter the glass in houses and other buildings for 10-15 km along the coast.
But no one even heard the explosion. None.

It can be concluded that the dispersion is associated with the destruction of the airframe of the aircraft upon impact with water, with further pulling apart of individual parts by the current, which, by the way, is very powerful on east coast World Cup

Now, about the passengers...

I would very much like that no one would draw false conclusions, based only on passenger train on board.

This is the passenger side of the MO. He constantly carries someone; Not musicians, so generals, not generals, so the embassy apparatus, not ambassadors, so military advisers, and even just military personnel on rotation. It could fall three months earlier, and two weeks, and a month later.
And in each case, we would get a tragedy on a national scale.
To be honest, I crossed myself when I found out that there were no 90 officers of the General Staff on board. That would be a LOSS!

Of course, a terrorist attack or sabotage cannot be completely ruled out. Moreover, to raise from the seabed ALL, which would help to give an unambiguous answer to the presence malice- just not realistic.

But if you think about the terrorists, then it was much more effective to blow up a civilian rather than a military side. And even in the case of the military, it was possible to plan it in such a way that not media representatives and musicians would be on board, but generals, for example.

I am firmly inclined to believe that the Tu-154B crash is the consequences of the Federal Law No. 94 adopted in our country and, as a result, the result of the September repair of the side.

Climb.

Pilots need to develop the habit of comparing attitude readings on the first turn, regardless of the navigator's report. The roll on the turn is set and controlled by the pilot; he reacts to the mismatch of artificial horizons - with his hands, in which he holds the helm.

Setting the pressure to 760 mm on altimeters in difficult conditions is made by the navigator, and this is the best option when the captain is piloting. Experienced navigators, setting 760, translate the pressure value through 760, then return exactly to 760. This is necessary in order to reliably record on the MSRP that the crew did set 760; there were cases when, in a chatter, the hand did not bring the number 760 to division by half a millimeter, the MSRP did not record the pressure setting, and claims were made against the crew.

After setting the pressure and putting the aircraft on the exit course, the next task for the crew is: how much will we have time to gain on the way out?

In the first seconds after takeoff, the crew already has an idea about the balance and takeoff weight - whether they correspond to the calculation or differ from it. After cleaning the mechanization and accelerating the speed, it is already possible to get an idea of ​​the rate of climb of the machine. And you need to know the temperature at altitude in order to predict the rate of climb in these conditions.

If, according to all estimates, it turns out to gain a given level just right next to it, it is better to gain altitude, maintaining the speed with the autopilot "descent-ascent" handle - this is the best option that allows you to maintain vertical speed with minimal errors. The use of the ACS "Stab.V" mode in the set, especially when centering closer to the rear, leads to a buildup in pitch and a loss of average vertical speed; if at the same time the toggle switch is turned on "in chatter", the buildup sine wave will be even larger, because the speed tracking system becomes coarse and does not have time to respond to its small changes.

When approaching a given echelon, it is not necessary to set a vertical speed of 5 m / s for 200 meters and sneak up - this is ugly. For example, I keep the calculated vertical up to a difference of 100 m, then I decrease the pitch with the autopilot handle, guided not by the delayed variometer, but by the rate of movement of the numbers in the altimeter window. It is this pace that determines the change in vertical speed. As soon as the numbers in the window begin to stop, I, without looking at the variometer, again slightly deflect the autopilot handle to dial. With such small movements of the handle (wheel), you can easily and confidently achieve that the desired number appears and stops in the window; at this moment, making sure that there is no tendency to increase or decrease, I press the button "Stab. N". At the same time, the acutely responsive altitude tracking system sets the desired height with light twitches of the elevator, and as soon as the variometer needle reaches zero, you can turn on the toggle switch "in a chatter", rude the system - the elevator stops twitching.

If it becomes necessary to turn off the toggle switch "in a bumpy", it is necessary, in order to avoid jerking the elevator, first turn off the height stabilization mode. Practice has shown that an error accumulates there, and always in one direction, therefore, you need to remove from the "Stab.N" mode only forward, away from you, overcoming the tendency of the aircraft to turn up its nose.

If it is clear that we do not have time to take the given echelon to the exit, we must not be shy and ask the dispatcher to allow us to pass the point in the set. You should not spend kinetic energy on a dynamic set, and then hang in hot air and wait until the speed accelerates again.

Better let the dispatcher on the ground press the button and coordinate as much as possible. We must always remember who works for whom, and not be shy.

When changing the echelon to a higher one, there is often a doubt, "whether we scrape together." Experience has shown: if at 10600 the angle of attack is close to 4 o, with the calculated number "M", you can dial 11600. Even if the temperature overboard increases by 5 degrees during the climb, this will not interfere with the climb.

If a decision is made to bypass the storm front on horseback, it is necessary to start recruiting in advance in order to have time to recruit the highest echelon with a guarantee. It is very dangerous to overcome the remaining few hundred meters of altitude above the cloud tops in a dynamic set, losing speed. It is impossible to visually determine a sufficient climb angle, and there is a high probability of losing speed at the top of the cloud.

If there is a need to gain maximum altitude in a minimum period of time, then it is possible to use the kinetic energy of the aircraft, losing speed in the dynamic climb. The best result is obtained if you start climbing 500 m below the given flight level. At 500 m, there is just enough margin of inertia with a loss of speed from 550 to 500 km / h. The vertical speed is best kept constant, about 15 m/s, and all the time to compare the rate of decrease in speed and increase in height.

Practice has shown that the most optimal climb occurs at a speed of 550 km / h. If there is not enough time to reach a given level with a headwind, there is no point in reducing the ground speed by reducing the indicated speed and climbing at a speed of 500. Reducing the vertical speed will negate the advantage in time, and, ultimately, you will lose.

If, after flying at a speed of 500 km / h, you need to accelerate the car for further gain, then acceleration should be carried out strictly in level flight. Acceleration with a slight climb, at 2-Sm/sec, will not save anything, and the aircraft accelerates very reluctantly, especially at altitude.

In order for the transition from the "Stab.V" mode to the "Stab.M" mode to take place without the jerk specified in the flight manual, you need to remove the "Stab.V" mode (away from yourself) with the wheel, and then take it a little with the same wheel on yourself and then press the "Stab.M" button; i.e.: it is better to make this jerk softer with your hands than to entrust it to a rough machine. Sometimes it is possible to switch from mode to mode completely inaudibly, and the overload does not change. The meaning of the operation is to remove the accumulated error, due to which, in fact, a jerk occurs.

At high vertical speeds, it is necessary to report on the occupation of a given intermediate level in advance, about 300 meters. If, as usual, the dispatcher has a hitch, a few seconds can be gained as follows. It is necessary to keep the speed not 550, but 540 300 meters before the flight level. While the dispatcher is determined, gives space, etc., you can slowly reduce the vertical speed, preventing the forward speed from accelerating too vigorously. Until the forward speed reaches 575, usually the controller finally sets a new level, and there is no need to remove the mode and transfer the machine to level flight.

When piloting in a climb in the helm mode, the main difficulty is maintaining the airspeed. In order to anticipate tendencies to change speed, special attention must be paid to the constancy of the pitch angle. The peculiarity of the aircraft is the large length of the fuselage, and any change in the pitch angle creates a desire of the spaced masses to increase this change. And although the stability-control system helps piloting, practice shows that success in maintaining speed, namely in climb, where speed constancy is the basis of piloting stability, is achieved by those pilots who know how to keep the pitch on an uncomfortable artificial horizon. On the contrary, those pilots who simply react to a change in speed swing the car in pitch.

Particular attention should be paid to the pitch on a sharp turn. It is necessary to make a rule for yourself: first look at the pitch, and then at the speed.

When maneuvering in climb, including when avoiding thunderstorms, one must constantly remember that airspeed can be easily and imperceptibly lost. In any case, at high echelons, the indicated speed should not be allowed to fall below 450 km / h, with the obligatory control of the reserve in terms of the angle of attack.

When flying in the spring-summer period, the outside air temperature is of particular importance. In summer, there is often a significant deviation of the temperature from the average values ​​in the direction of increase, and this phenomenon takes on special significance at high altitudes.

When flying at high altitudes, close to the practical ceiling, the thrust of the engines depends significantly on the discrepancy between the ambient air temperature and the parameters of the standard atmosphere. At an elevated temperature relative to ISA, the available thrust decreases significantly, and the required thrust for flight increases significantly. At the same time, maintaining level flight requires significantly larger required angles of attack and increased engine operation. The climb is significantly worse and takes much longer due to the reduced rate of climb.

Thus, flying at flight level at a higher outside air temperature relative to ISA is characterized by significant differences from flying in ISA:

Decreased margin in angle of attack;

The risk of stalling the aircraft from an accidental gust increases;

The drag of the aircraft increases due to the flight at high angles of attack;

The echelon set time is increased;

The possibility of vertical maneuver when bypassing thunderstorms is limited;

The practical flight range of the aircraft is reduced due to increased fuel consumption.

When preparing for a flight, the crew must take into account that the step climb required for the most economical flight mode will differ significantly from the calculated one. When running out of fuel, which allows, under ISA conditions, to gain a further echelon according to the flight manual, exceeding Tnv from ISA by + 10 ° will not allow this to be done in estimated time, which means that the flight at a less favorable lower flight level will continue more time. Thus, in hot weather, it must be remembered that it is possible to reach the most fuel-efficient flight level only in the second half of the flight, when the upper flight level is no longer feasible.

In this situation, it is better for the crew to pay attention to the choice of a flight level that is more favorable downwind. In general, fuel economy in flight depends much more on the correct use of a tailwind or competent "avoidance" of a headwind than on flying at the highest possible flight level.

In climb, when Tnv deviates from ISA towards warming, the crew can observe at what rate the range between the current angle of attack and the red sector decreases, compared to normal climb. Based on this difference alone, an experienced crew can already conclude that it will not be possible to reach the highest echelon.

When approaching a flight level close to the practical ceiling of the aircraft under these conditions, the critical angle of attack also decreases significantly; at the same time, the dangerous red sector of the AUASP device comes close to the arrow of the current angle of attack. A small reserve in the angle of attack and a vertical speed in the range of 1.5-2 m / s indicate that the aircraft has reached the practical ceiling. In this case, it will be very problematic to accelerate the car to such a speed at which it is possible to remove the engine mode from the nominal one, and the aircraft will reduce the pitch to an acceptable drag. If this fails, it is better to descend to the previous flight level: the flight on it will be more economical than when the car is "crossed" at a higher flight level.

A small margin in the angle of attack on the ceiling does not guarantee a stable flight. With small atmospheric disturbances, the fluctuations of the pointer of the angle of attack can reach the red sector. Flying in such conditions is simply dangerous, and at the first activation of the AUASP alarm, you must immediately descend to the level at which the stall margin will increase.

The aircraft may hit similar situation not only in climb, but also in level flight: when crossing the frontal section and entering the zone of the so-called "stratospheric warming". However, it should be understood that a sharp, within a few minutes, warming in level flight never happens; usually the change in Tnv occurs over a longer period of time.

Bypassing thunderstorm centers above the clouds is dangerous precisely because of the small margin of aircraft stability in conditions of a possible entry into a zone of strong turbulence.

An attempt to "scrape" the upper echelon in conditions when the power reserve is exhausted leads to long-term operation of the engines at nominal mode, and all imaginary savings "burn out" in climb. Such a technique justifies itself only if there is confidence that the wind conditions are significantly better at the upper echelon and it is expected that they will last the rest of the flight (as a result of a survey of oncoming crews). But practice shows that at high altitudes in summer there is almost no significant difference high winds. Therefore, the main criterion for choosing a flight level should not be economy, but flight safety.

When crossing a thunderstorm front with a climb above the upper edge, it is necessary to take into account the possibility of getting into an air layer with a significant deviation from the ISA towards heat during the climb. Otherwise, the plane may unexpectedly "hover" near the approaching thundercloud, contrary to the captain's calculation. Climbing in the summer near thunderstorms must be started much earlier in order to have time to take the highest echelon to the danger zone. In such cases, it is better to ask the boards for the temperature at altitude and make a decision in advance.

In general, air temperature control at the flight level during the summer period is strictly mandatory. An experienced captain controls the temperature both during the ascent and at flight level, and chooses the option of occupying an economical flight level, in accordance with changes in Tnv along the route and in altitude. Even in consultation with the forecaster, he outlines in advance the boundaries for changing flight altitudes in accordance with the predicted temperature changes at altitude.

The main attention in climbing, in addition to maintaining flight parameters, is given to changes in ambient air temperature and margin in angle of attack, as well as instantaneous fuel consumption. If the temperature differs significantly from the ISA towards warming, the margin for the angle of attack decreases to 2.5 degrees or less, and the fuel consumption in the nominal mode decreases and approaches the values ​​of the consumption in level flight, it should be concluded that the conditions do not allow climbing, which means that you need to go in level flight and run out of fuel until the reduced flight weight allows you to continue climbing.

The crew should always remember: the risk of stalling the aircraft at high angles of attack is not compensated by possible fuel savings. If there is not enough fuel, there is a chance to refuel. If there is not enough margin in the angle of attack, you can die.