What is an airplane stall? Recovering an aircraft from a stall

2024 Author: Henry Conors | [email protected]. Last modified: 2024-02-12 02:46

Professionals know firsthand the problem of flight safety, including aircraft stalling. It has been solved for many years, but research is moving unacceptably slowly, almost everything remains in place. At the same time, aircraft stalling is being studied much more actively abroad, and, what is most interesting, with the active participation of Russian specialists. And many nuances have already been clarified, and methods have been worked out to bring the ship out of a critical situation. We need to do this in every possible way in Russia, using extensive knowledge of this subject and the practically invaluable experience accumulated by our pilots. This is extremely important today - the ability to overcome the stall of an aircraft - but so far the topic remains unclaimed, unfortunately.

What to do

In our time, computer technology has reached a level that allows you to create a variety of simulators. And why not use this process for the benefit of aviation moreon a large scale? Taking into account the experience already gained, it would be possible to create a simulator that simulates the stall of an aircraft, so that pilots of transport aircraft could receive basic practical skills and prevent the device from entering a critical mode, as well as the ability to bring the aircraft out of such a situation.

Absolutely all accidents, when the aircraft enters the SOS (difficult spatial position), as well as in the stall mode, have a single common causal relationship. First of all, this is the psychological unpreparedness of the crew to recognize the beginning of a dangerous situation, and therefore the inability to take actions that are necessary when the aircraft stalls.

What is this?

Stalling off flight level is a dangerous violation of the ship's flight position. For example, incorrect pitch angle or excessive roll. Roll above 45° and pitch below -10° or above +25° are considered unacceptable, which is called the difficult spatial position of the aircraft in space. In operation, normal attitude is acceptable up to thirteen percent of possible values (for example, ninety degrees pitch and one hundred and eighty degrees roll.

Aircraft stall mode catches pilots almost unarmed. Commercial pilots prepare to fly an aircraft by a maximum of a quarter of these values (pitch from -10 to +30, and roll from zero to 45 degrees). However, in fact, when a complex spatial situation arises, these limits are exceeded, and significantly. Usually, if an aircraft hits an NGN, it is always both overspeed and overspeed.the overload is much more significant.

About critical modes

If we analyze the actions of the crews that have crashed, we can conclude that most often the pilots themselves do not see the approaching danger of a critical flight mode when the aircraft stalls. And once inside this situation, they cannot correctly recognize the causes and take the necessary actions to get out of it. And if the actions of the pilots are correct, then in most cases the planes get out of a critical situation. If the theoretical and - most importantly - practical training is appropriate, then getting into an emergency situation can be avoided altogether.

Periodically and very often civilian airbuses, for one reason or another, fall into a critical mode, and they are not able to bring the aircraft out of a stall. This is not only a stall, there are problems with exceeding the limits for overload and speed, and a difficult spatial position. In most cases, pilots act incorrectly and crash. Obviously, only pilot training can solve such problems. They must know exactly everything about creating critical modes and how not to fall into them. Even better, they should be able to get the aircraft out of them, and safely.

Training

The main direction of pilot training is the availability and creation of new technical means for training, which will allow simulating the widest flight areas withaccess to different critical regimes. Nevertheless, twenty years have passed since the obviousness of this problem, but the situation has changed very little. Such conversations are going on, and at the highest levels, but so far they have not begun to teach line pilots the techniques and methods to help prevent a critical situation, and if one develops, then the existing skills will not allow them to get the plane out of it competently.

After every large-scale plane crash, such talk becomes louder for a while. As soon as a plane stalls, it gives rise to another burst of debate over the eternal questions of "what to do" and, even more so, "who is to blame." A few months later, the tragedy is forgotten, and further conversations are not going on. The Interstate Aviation Committee (IAC) in the reports has to write the same thing over and over again, with recommendations to airlines and authorities to improve the training of pilots in preventing falling into critical modes and the ability to exit them.

Tests

When a transport aircraft undergoes flight tests for its certification, the minimum allowable stall speed of the aircraft must be checked. These are probably the most difficult and most interesting types of tests. Prior to this, special training is required to bring the aircraft out of the SPP, from various spins on an aircraft of the class that allows you to do all this.

Here every chance is used to acquire new skills and knowledge. Heavy aircraft are not subject to such a check, although in real operation they also stall from time to timethe plane goes into a tailspin. To conduct such a test, calculations are made in advance, and with heavy machines it is very difficult.

Disasters

Mathematical modeling of flight regimes, if it is associated with a non-stationary flow, does not move forward yet. And it is necessary to solve such problems, because there have been a lot of accidents in civil aviation lately. This is a consequence of the loss of control when an aircraft crash or stall occurs in an air pocket. The pilots lose their spatial orientation, and the aircraft has already gone beyond the flight restrictions.

From 2002 to 2011, twelve accidents occurred for this very reason, when commercial jetliners became uncontrollable. The result was the death of almost two thousand people. This is the most common cause of worldwide disasters - loss of control, it has the first place in this terrible list.

How they teach

Training of line pilots takes place in programs that do not include training in such important elements as the recovery of an aircraft from a stall. In Soviet times, pilots studied on the Yak-18, on which any aerobatics is possible, and therefore, until the eighties, they knew what spins, bank turns, slides, dives, and the like were. Moreover, in these situations they were personally at the helm. Now the programs are very much reduced with the motivation that a civilian pilot does not need this.

He works with passenger traffic, and therefore must be able to fly exclusively withinflight restrictions. In addition, there is no need to spend money on additional training, and time is saved. And pilots subsequently get into critical situations, moreover, quite often. Malfunctions can happen anywhere - in the control system or when an engine fails, which leads to a loss of spatial orientation for the crew, and many more different situations can develop. The main thing is that the number of such tragic episodes began to increase sharply.

Consequences

Experts are sure that the root cause of most major air crashes in the past few decades is the lack of skills and knowledge, the inability to act in certain critical situations. There may be both pilot error and external causes, but in either case the pilot does not know what he should do. For example, in 2008 in Perm, Boeing 737-500, on which the indication of the attitude indicator is direct view, and not reverse, as on domestic aircraft.

Pilots previously worked on manual control, but with a different type of equipment were not ready to accept the data they received. As a result, a whole series of actions took place that the crew would have been better off not doing, because the plane got into a situation that ended in a disaster. In this case, the reasons are specific. It is under-learning with specific learning gaps. Pilots most often cannot cope with the situation because they do not know what and how to do, and therefore are in a state of complete confusion and even shock. Although to get the plane out of this situationsometimes even easy. It is important to know how.

Examples

When the normal flow of air around the wing is disturbed, the aircraft falls into an air pocket, this is what is called a stall. Its lifting force drops sharply, the nose or tail lifts up, there is a roll on its side and even the introduction of the aircraft into a tailspin. The stalling speed of an aircraft is the main prerequisite for the consequences that the world has seen quite often in recent years. Planes get into the turbulence zone almost constantly, but for some reason, more and more passengers get injured of varying severity.

This is what happened when landing in Jakarta with an Etihad airliner, when more than thirty people were injured, it was the same with the ships of Allegiant Air and JetBlue, where five and eight people were also injured, respectively, and, finally, a high-profile case with a plane flying to Shanghai from Frankfurt, where seventeen people were injured.

More examples

Stalling an aircraft into a tailspin is a transition to an extremely dangerous flight mode. Pilots are very often unaware of the impending danger, although an alarm warns of an approaching stall, and therefore the simplest measures are not taken to avoid such a situation.

And it happens that they do something completely different, directly opposite to the necessary actions. Such was the stalling of the TU-154 aircraft (Pulkovo Airlines) in 2006. The pilots wanted to bypass the thunderstorm from above, losing speed and falling into a stall. In the same way, the A330 aircraft (Air France) crashedin 2009 over the Atlantic Ocean.

Main reason

If the pilots of the crashed airliners were able to recognize the danger and prevent it, and if they were able to take the aircraft out of the emergency situation, there would be no disasters. Great knowledge and even greater skills are needed.

According to the analysis, ninety percent of the accidents occurred purely due to the ignorance and inability of the pilots, and in the same ninety percent of cases, the disaster could have been prevented. Only at a very low altitude is this impossible, as, for example, happened at Sheremetyevo with the Yak-40 aircraft, where TV journalist Artyom Borovik died. Then the stall of the aircraft happened immediately after the liftoff, the altitude was not gained at all.

Conclusions

The beginning of perestroika was marked by the arrival of new people in aviation who were only interested in profit, and in pursuit of it they were not interested in any safety issue. But in the USA, on the contrary, it was in the nineties that many private training centers were opened, where the most serious airlines sent their pilots to take a special course, which included both theoretical and practical training. Small planes were used for flights, since taking such a course on a large one is both dangerous and expensive.

It is even cheaper and safer to train pilots on simulators, where you can work out any piloting skills in all critical modes. Another question is that an adequate mathematical model for, for example, stalling does not yet exist, and manyit is still impossible to work out other critical modes on the simulator. It is necessary to conduct business in this direction so that the pilot can really feel that he can bring the plane out of the stall, then he will gain confidence and will act differently in order to prevent a disaster.