Flaps? Consider this legend! “Flaps are very critical. Why flaps do not close on an airplane

According to experts, there have been cases when, instead of the "flaps-15" mode, the switch was accidentally put in the wrong position.

As I wrote earlier, the preliminary results of the decoding of the flight recorders of the Tu-154 aircraft of the Russian Ministry of Defense that crashed near Sochi showed that the development of an emergency situation on board occurred on an airliner. Journalists from Moskovsky Komsomolets asked experts to comment on what happened on board the airliner.

According to one of the experts, if there is a mismatched release of the flaps, then the jammed flap remains in the position in which it is stuck.

"I.e intkbbee the system cuts off all electric motors that are used for the release and cleaning of mechanization (flaps). At the same time, this tracking system releases a serviceable flap, or removes it to the very corner at which the jammed flap remained. In this regard, some have a question: is it possible that the crashed "Tu" was so old that it was not equipped with such a system? No. I flew on this plane and I can say that only the very first Tu-154s did not have it. Later, planes with the designations Tu-154A went, then "A-1", "A-2", then - Tu-154 B, etc. The latest modification with the designation "M". And everyone had this system. So why does one of the crew members scold the flaps in his last words? I think at that moment he just realized that he had made a mistake," the specialist said.

The expert notes that in this aircraft, the switch for retracting and extending the flaps is located above the windshield of the cockpit. If the ship's commander is piloting, then the co-pilot releases the mechanization, and if the co-pilot is piloting, then the commander controls the switch.

“There are grooves in the switch where the switch is locked in three different positions: “flaps-15”, “flaps-28” and “flaps-45”. And when the commander taxis on takeoff, he gives the command: “flaps-28” The co-pilot puts them in the take-off position.The plane (this, however, depends on the flight weight) takes off from the ground at a speed of 270-290 km per hour. Then, when it needs to cross a height of 120 m and go higher, it accelerates to a speed of not less than 330 km per hour, and then a command is given to clean the mechanization. That is, from the "flaps-28" position, their switch is set to the "flaps-15" position. Meanwhile, the plane continues to accelerate. But there have been such cases - especially if the chatter is in in the air - when instead of "flaps-15" the switch was accidentally, by mistake, set to position "0". This, of course, is an assumption, but just imagine: from "28" the flaps are immediately retracted to "0". "clean wing", that is, when mechanization has already been completely removed, is not provided. the aircraft reaches a critical angle of attack, at which it is possible to stall into a tailspin. If something like this happened, then it can definitely be regarded as a crew error," he stressed.

Another expert described the possible situation on board the crashed Tu-154 in a slightly different way.

“If the flaps began to retract out of sync, then the point here is not that there is not enough lift. There is enough of it. It’s just that the difference in lift on the left and right half-wing leads to the fact that the roll angle develops intensively. If you don’t immediately respond to this, then you can’t do anything further, since the speed grows and, accordingly, the difference in lift forces on the half-wings grows, and even the rudder travel is no longer enough to compensate. according to the transcript of the negotiations, which appeared in the media, everything was probably even worse there: the pilots removed the flaps instead of the landing gear ... And they killed themselves. In this case, there are no options at all ... ", he said.

Preliminary decoding data of the "black boxes" reduced the number of versions about the causes of the Tu-154 crash. It could have been a pilot error or a plane crash.

Read also 21:13 December 27, 2016 The transcript of the last minutes of the life of the pilots was published by Life. It is known that at first the pilot reports that the speed is 300, the racks are taken. Then a sharp beep sounds. One of the pilots exclaims: “Flaps, bitch!”. And then a cry sounds: “Commander, we are falling!”.

Investigators will determine the exact cause of the incident. In the meantime, experts are putting forward options due to which the board could collapse into the sea. "Snob" found out how the Tu-154 takes off and why we need flaps, which the pilots shouted about before they died.

How the Tu-154 takes off:

First, the pilot receives permission from the controller to take off.
-Then the pilot turns off the brakes, opens the flaps, the plane picks up speed.
- At a speed of 260 km / h, the front wheel of the chassis begins to rise.
-At a speed of 300 km / h - the plane breaks away from the runway.
-After a break of 5 meters, the landing gear is retracted.
-At 120 meters of lift-off, the aircraft changes its position from 20 degrees of inclination to 15
-At a speed of 360 km / h flaps are removed. The stabilizer moves from the takeoff position to the flight position. The aircraft levels out the degree of inclination to 0.

What are flaps for and what could happen to them

Flaps are special devices on the back of an aircraft wing. They are symmetrically located deflectable surfaces.

The aircraft takes off from the ground only when the lifting force exceeds the weight of the aircraft. This is what flaps are for. They change the configuration of the wing, due to which the lift force increases, and the speed during takeoff and landing decreases.

On the Tu-154, the flaps could be retracted out of sync - one of them could jam. This could cause an uneven increase in lift.

Expert opinion

Read also 20:04 December 25, 2016
According to the honored pilot of the Russian Federation Konstantin Onokhin, the Tu-154 pilots had 3,000 flight hours. This is a lot for a fighter, but this is not enough for transport aviation of international flights. The Tu-154 is a good aircraft, but it requires the qualifications of the commander and crew members to be above average.

The expert recalls that it is better for planes to take off and land against the wind. But Sochi airport is difficult in this regard - the wind blows from all directions there. With the climb, the tailwind could intensify and blow in the tail, the speed dropped, and the center of gravity became forward. Tu-154 with centering has a special moment - the aircraft has a fourth fuel tank in front, which helps to lower the center of gravity forward. It is very dangerous.

“The pilot kept the helm at the limit, but still there was a touch on the water surface,” explains Konstantin Onokhin. - Why such a scatter of the remnants of the aircraft? It's like throwing pebbles like a pancake on a lake. That's the plane as well - a few hits on the water, and then under the water. It’s a pity for the guys, they got into a very difficult situation, from which it turned out to be impossible to get out.”

Also now there are opinions of pilots that the pilots could make a mistake and remove the flaps instead of the landing gear.

Note that so far all versions of specialists are conjectural. The exact and official reason will be named after studying all the facts of the disaster.

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

“According to preliminary data, the flaps worked out of alignment on board, as a result of their absence, the lift was lost, the speed was not sufficient to climb, and the plane fell down,” said a source in the operational headquarters for work at the scene.

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

Andrey Litvinov

1st class pilot, Aeroflot

— Flaps — it is very critical. We ( pilots — ed.) at the very beginning it was assumed that these were flaps - as soon as it became clear that this was not fuel and not the weather. There were several versions - technical, pilot error. But it could be both. A technical problem led to a pilot error.

Flaps are needed only for takeoff and landing - the wing area increases, lift increases, therefore, the aircraft needs a shorter takeoff distance than without flaps. You take off with the flaps, climb, the flaps retract. But they may not be removed if something is broken, or they are not removed synchronously - one is faster, the second is slower. If they don’t clean up at all, it’s not scary, just the plane flies and flies itself. He does not go into a dive. It’s just that the commander reports to the ground that he has such a technical problem, returns to the airfield and sits down - with the flaps extended, as it should be during a regular landing. And the engineers are already figuring out what the problem is.

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

I flew the TU-154 for 8 years. I had no situations with flaps, there were minor failures, there was nothing serious. It was a good reliable aircraft in its time. But that was 25 years ago. This is a product of its time. Aeroflot has all new planes - we fly on Airbuses, on Boeings. And the Ministry of Defense flies on the TU-154. Yes, you need to make your own planes, yes, but at least let them take a superjet. On modern aircraft there are a lot of protection systems, this is actually a flying computer. If some kind of situation happens, the automation does not allow the plane to fall down, it helps the pilot a lot. These planes are all in manual mode, all in manual control. But this does not mean that it should fall, it should be technically sound. It needs to be serviced. The question to the technicians is why such a serious breakdown happened to this aircraft. Any person can make a mistake. The crew has experience, it was, but military pilots, in principle, fly little. A military pilot flies 150 hours a year. And civil - 90 hours a month.

Surprise could still work, they did not expect such a development of events, there was not enough reaction to cope. This does not mean that they are inexperienced. Don't forget that it was 5 am. Sleep itself, the body is relaxed, initially inhibited reaction. We have been saying for a long time that night flights should be banned or reduced to a minimum, we should strive to fly during the day, as many European companies do.

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

Source close to the investigation

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

Vadim Lukashevich

Independent aviation expert, candidate of technical sciences

- Non-retractable flaps are not a disaster. This is a very unpleasant event, but nothing terrible should happen from this. And in my opinion, a combination of circumstances and the actions of the crew led to the disaster in the Black Sea.

The essence of the meaning of aircraft flaps is to increase the lift of the wing at low speeds. How the wing works - the higher the speed, the greater the lift. But when the plane takes off, the speed is still small, just like during the landing process. And so that when the speed drops, the lift force does not decrease, the flaps in question are released. You also need to understand that during takeoff the flaps do not extend as much as during landing. When taxiing the aircraft on the runway, the flaps are already released, and at the time of takeoff, the landing gear is sequentially removed, slowing down the car, and after 15-20 seconds, the flaps are also removed, which interfere with the growth of the aircraft speed. In addition to lift, they also create additional air resistance and an additional dive moment - when the plane "wants" to lower its nose.

What happened at the time of the crash? A heavy, loaded plane, flooded with fuel, takes off, the pilots retract the flaps, but for some reason this does not work. In theory, you can continue flying normally and in this state, without picking up speed, you can turn around and go for a landing to fix the problem. You can sit down with this position of the flaps, just the touch speed will be higher and it will not be very easy. But there was obviously no such solution. Perhaps the problem with the flaps was not immediately noticed, but when they saw how the plane began to lower its nose, it was possible that the words decoded from the recorder were uttered.

It seems that there is some clarity in the investigation into the causes of the Tu-154 crash in the Black Sea. Analysis of the flight recorders and leaks from sources close to the investigation point to a problem that has often led to tragedies in the air: out-of-sync flaps. It remains to understand who is to blame for what happened - the equipment or the crew.

By Tuesday evening, a preliminary analysis of the black box records of the Tu-154 that crashed on Sunday was completed. The version about an error in piloting technique is confirmed, an informed source reports. According to him, this follows from the analysis of the recorder data.

“It was necessary to first remove them halfway after the liftoff, and only after picking up speed - completely remove them. And the “right-winger” Filippov headlessly removed them in one fell swoop. And crashed the plane

At the same time, the media previously reported that the pilots were recording problems with flaps in the last seconds. In particular, one of the pilots exclaims: "Flaps, bitch!"

Earlier, test pilot Magomed Tolboev already stated that the cause of the crash could be problems with the flaps. According to him, in this case, "the plane instantly turns around its axis." “Neither the commander, no one has time to say a word, they are thrown there like a herring in a barrel,” Magomed Tolboev noted.

Vice President of the Federation of Aviation Fans, Honored Test Pilot of the USSR Viktor Zabolotsky specified in a commentary to Life that if there are problems with the flaps, the plane can become uncontrollable. “One wing has a large lifting force, and the second one has a small one, naturally, the plane will turn over,” he said.

An Interfax source at the Emergency Operations Headquarters also said that the Tu-154's flaps worked inconsistently. The inconsistent operation of the flaps could, in turn, be caused either by technical reasons or by the error of the crew member responsible for their work.

However, until the records of the remaining black boxes are deciphered, experts do not know "where the crew's hands were" - what the crew commander and co-pilot did at the fatal moment.

As experts explain, right in front of the co-pilot is the lever for extending and retracting the flaps. The commander instructs: "Remove flaps" - and the co-pilot removes. How exactly the crew acted will be clear later, but some conclusions can already be drawn.

Honored Pilot of the USSR, former Deputy Minister of Civil Aviation of the USSR, President of the Civil Aviation Partner Foundation, who himself flew the Tu-154, Oleg Smirnov, in a conversation with the VZGLYAD newspaper, emphasized that his first assumptions about the causes of the plane crash were also associated with flaps. The fact is that the plane disappeared just at that point in the flight where the flaps are retracted.

“The flaps move out from under the wing, increasing its area and at the same time changing the curvature of the flow. This is done to increase lift and decrease speed. The flaps are released both before takeoff and during landing in order to produce it at a lower speed, ”Smirnov explained.

Smirnov stressed that the Tu-154 is equipped with automatic equipment, which, in the event of non-synchronous operation, stops the movement of the flaps. Usually the crew is not to blame for the out-of-sync retracting of the flaps, only the technician is responsible for this.

“But if this audio recording appeared, it means that the automation did not work. It all happens so fast that it leaves no hope of carving out a fraction of a second to press the transmitter button and report what happened. The ship's commander gives the command to release. The flight engineer has one lever. He moves it, and the flaps go right and left. If the flaps are extended or retracted out of sync, the automation should stop them, ”he said, adding that deciphering the parametric black box, which contains signals for the operation of mechanisms and possible failures, will help clarify the causes of the crash.

“It happens that the equipment fails, the flaps can be removed out of sync,” another source of the VZGLYAD newspaper, a former high-ranking military pilot, echoes Smirnov. “Then we need to stop cleaning them right away!” Otherwise, the plane will simply collapse in one direction. I haven't experienced this myself, but others have. Those who had time to stop cleaning are alive, those who did not have time were buried.” The interlocutor did not even rule out that the Tu-154 crew forgot to release the flaps before takeoff.

The interlocutor cites the example of the death of the Tu-95RTs aircraft on January 25, 1984, the crew of which was headed by a military pilot of the first class, Major Vymyatin.

“I took off from the Olenya airfield on the Kola Peninsula. After 1 minute 55 seconds during the climb at a speed of 346 km / h and an altitude of 350 m, the crew prematurely retracted the flaps at low speed, - says the source. - There it was necessary to first remove them halfway after the liftoff, and only after picking up speed - completely remove them. And the co-pilot Filippov removed them in one fell swoop. The navigator told the commander - turn back on course. The commander entered the car into a roll and dumped the plane. All died. 92 tons of kerosene burned out for two days in a snowdrift. Something similar could happen here."

In the event of a pilot error, the question of the qualifications of the crew naturally arises.

Earlier it was reported that the commander of the crashed Tu-154, pilot first class Roman Volkov had more than three thousand hours of flight practice. In this regard, it was concluded that Volkov was an experienced pilot. However, Oleg Smirnov is skeptical about the figure of three thousand flight hours, calling it "cadet". The raid of Smirnov himself is 15 thousand hours, including on the Tu-154. There are pilots with 20,000 raids. Smirnov also recalled that each type of aircraft has its own characteristics. In addition, it is not clear from the flight figure exactly how many flights the pilot made on this type of aircraft and in what capacity - aircraft commander, co-pilot, etc.

“If all these thousands of hours the commander flew this plane, this is one thing. And if on other types, then another. The plane is different for the plane. It all depends on its weight, dimensions, placement of engines. Tu-154 is original in terms of aerodynamics. He has all three engines, each of which weighs more than a ton, in the tail, which means rear centering. Aerodynamic forces work differently here. Each aircraft has features, you learn them during retraining, and you always need to keep them in mind. In particular, when you retract the flaps, you have to be very careful,” explained Oleg Smirnov.

Yuri Sytnik, Honored Pilot of the Russian Federation, member of the Commission under the President of the Russian Federation for the Development of General Aviation, experience of flying the Tu-154 - more than 20 years.

On any aircraft, flaps are used in order to reduce the length of the takeoff run and the mileage of the aircraft during takeoff and landing. The plane takes off at a speed of 700-900 km/h, and comes in for landing at a speed of 280-220 km/h per hour, depending on the type of aircraft. Tu-154 comes in for landing at a speed of 260 km/h, and takes off at a speed of 280 km/h. There is a command "Frontier", "Rise", the aircraft is taking off. In order for the plane to take off at such speeds, you need to change the wing. For this purpose, there are slats and flaps. That is, they move out of the wing, increase its area, change the curvature, thereby increasing lift at a lower speed. And with a horizontal flight, such a swing is not needed, you need to transfer passengers faster, the plane accelerates to a speed of 800-900 km / h, the flaps have already been removed. Everything is compactly pressed into the wing, and it becomes faster. The aircraft continues to fly at that speed. Then, when the plane descends and approaches the airfield area, the flaps are again extended first, then the landing gear. On the Tu-154 flaps are released at 45 degrees.

Before takeoff, the flaps are extended on the runway. The aircraft taxis, flaps are extended for takeoff and set to 28 degrees. Further, the aircraft increases engine operation, starts the takeoff run, lifts off the ground, retracts the landing gear, when it reaches a speed of 340 km / h and an altitude of at least 120 meters, the flaps are retracted. At what stage of the case with this TU-154 are we talking about flaps? Unclear.

And those who write that the flaps were released inconsistently write nonsense. If the flaps are mismatched, there is synchronization when the faulty flap stops and the serviceable one “works under it”. I have other, for example, information, that the speed was 300 km/h, and we are talking not about the flaps, but about the rack (ed. note - the main power element of the aircraft landing gear). Something happened to the stand. Why did she stay on the ground and not in the sea? So he touched the ground after taking off from the runway? Dont clear. But I know that the stand was found on the shore. How did she get there? She is heavy! She weighs over a ton. How could she have been thrown away? What about a storm?

It is not clear what height it was. If this height was 15-20 meters, then it is clear what it is. And if the height was 200 meters, this is a completely different option. We do not yet know the true height, it is impossible to assert anything. If the height is 15-20 meters, then the crew made a mistake, and instead of retracting the landing gear, they retracted the flaps at low speed, at a speed of 300 km/h. In this case, the commander lifts his nose so as not to touch the water, puts the plane into the second mode and falls into the water. And if, after a height of 120 meters, the flaps began to retract out of sync, he simply turned over, and he was already in the water. But there is a system that controls this, it cannot be. Then everything would be different, the whole dynamics of the flight would be different, he would not fall, but gain his height. And here he is already lying one and a half kilometers from the coast. I don't think the flaps have anything to do with it. I think the crew did the wrong thing. Who was sitting in the right seat - the co-pilot or the checker? This is also a question.

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