In the language of the pilots “strike” — not the best shot that you can make in bowling. As a rule, this word in aviation, represent the collision of birds with aircraft (with the addition of the word bird (bird) — turns out the “bird strike”). In fact, birds collide with aircraft very often: it is possible this incident was, even during your recent flight, you just don’t know it. Usually such incidents do not lead to serious consequences, a bird weighing less than 3 kg is combusted in the engine. However, sometimes the planes even have extra to sit down from-for collisions with birds.
Only in Russia, officially recorded about 7,000 cases of “bird strike” during the year — in Europe this figure reaches 10 000. However, only about 5% of hits birds cause damage to aircraft. But for precaution all the planes after the collision, returning to the closest airport, and passengers connecting onto another flight with another crew. In rare cases, the damage is too serious, and become pilots in emergency situations. It happened with Airbus A321 Ural airlines, which is 15 August 2019 landed in a field near the airport due to the failure of both engines caused by collision with birds.
Airbus A321 Ural airlines after landing on the field, August 15, 2019
Why do birds collide with airplanes
In General, birds do not fly high. Most collisions occur at an altitude below 150 meters — that is just during takeoff or landing. The speed of the aircraft at this time is lower than the mark and quick evasive maneuvers to carry out difficult. The outcome mostly depends on what part of the plane beats the bird.
The greatest danger is getting the bird into the engine. According to the safety standards of large engines must be able to withstand a collision with a bird weighing less than 3.5 kg without the dangerous and quick release of sharp fragments of blades of the engines. In fact most engines can swallow a bird and only a little damage the blade. However, it is also damage: and if the bird gets bigger, collision with it can cause engine failure. The blades will begin to break down one after the other, causing a fire.
Pilots can extinguish the fire in the engine and disable it completely, only to return to the departure airport (if the incident occurred during takeoff) or to complete the landing with one working engine. All pilots are trained to control the aircraft with one engine, although this is very difficult: you have to go completely into manual controller and make a visual landing. Not long ago, the Japanese airlines plane was forced to make an emergency landing in new York, because a bird hit the plane, another plane was forced to return to Cardiff airport in Wales after a bird hit the engine.
Compilation of clips where the planes collide with birds
What happens if birds get into the engines of the aircraft
But it is quite another case is when the birds get into the two engines. In this case, they usually fly alone and in flocks, and it is dangerous. The scenario described above with one engine failure is repeated on the second, and the aircraft does not remain anything, except how to plan.
The actions of the pilots in this case depend on the height. If the incident occurred on 3-4 thousand meters, they can still turn the plane back to the airport and put him (or to complete the planned landing), though I must admit that the collision with the ground is very hard — it all depends on the pilot’s skill and his ability to “feel” a multi-ton machine. But if the aircraft did not gain height on takeoff (up to 1 000 meters), birds got into both engines and caused their failure, the pilots simply did not have enough altitude to maneuver. In the end they make the decision to put the plane where we have — on the highway, field (as in the case of a Board of “Ural airlines”), water and any other suitable, so to call it, the surface.
How many planes can fly without engines
If the plane took the train in the 10,000 meters, he can make at a distance of 140-150 kilometers, depending on the aircraft type. Here only birds at this altitude, do not fly, so all collisions occur much lower in altitude below 1 000 meters. That’s not even enough to plan 30 kilometers. Forced planning can bring to the fact that the nose of the plane will ride up too high
How to put planes without engines
If the pilots realize that the plane can not make it to the nearest airport, they make a decision about the landing of the wasteland (if available) or water (called “water landing” aircraft). This helps them APU — auxiliary power unit. It is a small engine equipped with the turbine, which produces energy, which in turn activates the action of all is necessary for the components of the aircraft from the rudder control and up to the dashboard.
One of the clearest examples of landing is an emergency landing A320 on the Hudson that occurred on January 15, 2009. The aircraft for US Airways in 1.5 minutes after takeoff collided with a flock of canadian geese, and he lost both engines. The crew safely landed the plane in the water of the Hudson river in new York. All on Board were 155 people (150 passengers and 5 crew members) survived. The aircraft just managed to gain a height of 975 metres and this was sufficient to expand the liner, taking off to the North, South, plan on the Hudson river, missing the George Washington bridge, and privodit liner. Later on these events was filmed feature film “the Miracle on the Hudson”.
The landing of the plane in the Hudson, January 15, 2009
In fact, if you try to reproduce this situation on the simulator, pilots in most cases will be able to return the liner to the departure airport. The problem is that in the simulator for the decision are given only 5 seconds (and such a situation is only practiced in the simulators). In reality, the pilots are required for about 20-30 seconds due to a stressful situation. So often pilots is not enough time to land the plane without incident.
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Best known for 21 cases managed of emergency landings of passenger aircraft on water, in 10 of them during landing no one was killed. One of them is the landing of Tu-124 on the Neva river — an accident that occurred in Leningrad (St. Petersburg) August 21, 1963. However, in the event the problem was not with birds: because of a defect of the aircraft fuel entered the engines, and they stopped.
Landing on the field is even more complex — pilots have to take into account the roughness of the surface topography and to calculate the proper speed to prevent the stalling of the aircraft and sit “on the belly” as gently as possible. Such planting shall be made without the landing gear because the landing gear with an uneven surface can damage the fuel tanks. The latter may lead to inflammation of the airplane, as happened with the airliner Sukhoi Superjet 100-95B. 5 may 2019 during a landing the liner was damaged, causing a fire (landing gear struck a fuel tank), in which the aircraft partially burned.
So August 15, 2019, the A321 pilots, can be said to have performed a miracle.
What happens if a bird hits the plane
Not only engines are at risk in contact with birds. The Windows in the cockpit, too, can be broken. But make them from three layers of laminated acrylic and glass, designed to withstand hail in the heart of the storm, so the birds do not pose a problem. The many layers also ensures the integrity of the aircraft even in case of damage to the outer layers. Also pilots are trained to enable heating of the glass below the ice would not numeral at altitude, before takeoff; so the glass becomes softer and more resistant to shocks. Read more about these technologies you can read in our news channel.
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However, sometimes birds do break — a special danger is posed by the geese and eagles, which weigh more than 5 kg.
Why engines do not close the grill from birds
Quite often there is an assumption that the engines must be protected by a grille, but it’s not so easy to do. The problem is that in order to effectively block the bird at a speed of 800 kilometers per hour, the grid needs to be very durable and thick, but it will prevent the flow of air into the engine. Engines effective because carefully designed to use the thin air at altitude, so the protective grille cons outweigh the pros. Yes and in contact with such a mesh into the engine the consequences can be far more disastrous than from a collision with birds.
How to prevent collision of birds with aircraft
Planes and airports are equipped with special devices, the publisher of a bird-scaring noises. But, apparently, not enough — even acoustic cannons and pyrotechnics don’t guarantee that zakulisnye birds will be on the windshield or engine of the aircraft. Therefore, the birds meet regularly with the aircraft, and final solution of this problem has not yet been found.
A considerable danger is also present drones — if collision are random, the pilots are often specially quadcopters flying near the airport. In December 2018 Gatwick airport in the South of England did not work for 36 hours due to the suddenly appeared in the sky drones. Because of the danger of collision of a passenger aircraft with drones was cancelled about 1,000 flights, resulting in more than 140,000 people were forced tens of hours to wait for the resumption of work. Dronesflying near airports, really dangerous. Faced with a small drone aircraft can crash.
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At the moment, researchers from the UK and from around the world are working on various sensors and materials, which will be able to assess the condition of the aircraft and eliminate the need to interrupt the flight after a bird strike. The idea was to create a wireless system that can determine the location and strength of damage. In the end, the pilots will be able to obtain information about the possibility of safe continuation of flight after impact, since each return trip to the airport is economically unprofitable for the airline. With more severe damage, the system will transmit them to Earth to equipment at the time of landing already knew what parts are needed.
And while there is no such system, warning sound and thorough training of pilots will remain our only defense against hits birds.