What is the depressurization of an airplane?

Even those who are well acquainted with the laws of physics and understand how it happens that a pile of metal rises into the air, sometimes still feel discomfort, thinking in flight that between them and hard earth is 10 kilometers. What can I say about ordinary inhabitants? Ordinary passengers are frightened even by the words "depressurization of the cockpit", not quite realizing what it is and what it threatens.

In flight

Cynics joke that you should not be afraid of aircraft, because each of them somehow returns to earth. If you think about it, only desperate brave souls can voluntarily get inside a fragile structure, which will rise 10-14 kilometers above the surface of the planet to deliver them to their destination. In fact, as statistics show, dying during the flight is not the easiest task.

Yes, there can be something out of the ordinary. Nevertheless, modern airliners and their pilots are sufficiently prepared for many emergency situations that in the past led to tragedies with numerous victims, and now they are only an occasion to make an emergency landing. All automatic systems are duplicated, maximally eliminating the human factor. If the equipment has refused, experienced pilots can often prevent a catastrophe or minimize its consequences. And yet sometimes you can not avoid troubles. What happens when the aircraft is depressurized? Is it possible to survive and what to do?

Depressurization of aircraft

At an altitude of 10,000 meters, the pressure is much lower than on the earth's surface. Still there is much colder, not enough oxygen for the normal functioning of the human body. Needless to say that even the very idea of a hole in the skin can frighten even the most experienced and quiet passenger? Modern cinema has brought common sense to the sacrifice of entertainment, and among ordinary people there is an opinion that even a tiny hole in the airplane shell, not provided for by its design, will necessarily lead to the death of all who are on board. In fact, everything is exactly the opposite - of course, damage to the skin can not be attributed to a perfectly normal situation, but to consider it as a catastrophe is not necessary. History knows a lot of cases when even large enough holes in the hull did not become a hindrance to the smooth end of the voyage. So, it is worthwhile to understand what is meant by the term "depressurization of an airplane" and what it means in practice.

Causes

When it became clear what a depressurization of the cabin of the aircraft, it is worth considering, in connection with which it can happen. In a normal situation, as it became clear, the liner is sealed and equipped with autonomous life-support systems so that passengers feel more or less comfortable. Nevertheless, sometimes the existing order of things is violated. The reasons can be both internal and external:

• Human factor - the actions of passengers or crew, leading to damage to the skin;
• Manufacturing defects - defective parts, violation of assembly technology, etc .;
• Damage by foreign objects - deliberate or accidental penetration of the structure by various means from outside;
• Abnormal situation - the conditions under which the load on the airliner is higher than the calculated one.

And then the situation, depending on what is happening, can develop quite differently.

What's happening?

Depressurization of the aircraft at altitude first of all threatens passengers with oxygen starvation and the so-called caisson, or decompression sickness. Contrary to the numerous catastrophe films that are inside the airliner, it is unlikely that they will be thrown out, unless they are fastened according to the instructions of the crew, and a huge hole is not in the immediate vicinity of them.

In real life, with relatively small damage to the skin, the aircraft is able to maintain the overall integrity of the structure, so that if there was no explosive decompression, instantly traumatizing people and leading to rapid hypoxia, the situation can be called quite controlled. The main thing is to notice in time the pressure drop and the decrease in the oxygen level in order to prevent a loss of consciousness in everyone who is in the cabin and, accordingly, a complete loss of control.

Effects

If the depressurization of the aircraft did not inflict injury on anyone in the first few seconds, this does not mean that there is no danger. If you do not take action, all passengers and crew are still threatened by the following factors:

• Low temperature - can lead to frostbite, general hypothermia, death;
• Caisson disease - vascular damage due to rapid pressure drop;
• Altitude hypoxia - insufficient amount of oxygen in the air;

What will end the depressurization of the aircraft, depends on how everything happened and the actions of the personnel and passengers. The flight can safely be completed without any negative consequences, and can become a disaster, even if the damage to the skin was minimal. Fortunately, as a rule, everything ends quite safely.

Security measures

Not the least role in what ends the depressurization of the aircraft, is played by how carefully the preflight preparation of both the aircraft itself and its crew is carefully carried out. A fairly wide range of factors play an important role: proper operation, thoughtful design, timely maintenance, regular inspections, etc.

Modern airliners are equipped with a large number of systems that constantly monitor the state of the aircraft throughout the flight. With proper experience, pilots will notice even minor failures in time and take the necessary measures to prevent negative consequences. But with sudden and serious changes, it is extremely important what will be done in the first seconds. So, any modern aircraft is equipped with special oxygen masks, automatically thrown over the seats during emergency decompression. Their work flight attendants demonstrate at the beginning of each flight during a story about safety. But that is not all.

Actions of the crew

The most serious problem with rapid depressurization is an acute shortage of oxygen, which causes breathing to become more frequent, and the head - to whirl from acute hypoxia. After a few seconds a person loses consciousness, and after a while irreversible brain cell death processes begin, so it is extremely important that the right actions are taken in the first moments.

Having discovered the damage to the skin, pilots should descend to a safe height of 3-4 kilometers in the shortest possible time. At this level, enough oxygen is needed to maintain vital activity and relatively normal functioning of the human body.

After the situation has stabilized, it is necessary to assess the situation and make a decision about emergency landing at the nearest accessible airport. The depressurization of the aircraft is a sufficient reason to stop the flight, as there is no guarantee that the destruction will not continue.

Activities of passengers

Very important is how ordinary people who experience decompression will behave. Firstly, it is necessary, if possible, to remain calm and not to panic. Secondly, you need to listen carefully to the instructions of the personnel and carry them out. If oxygen masks have fallen from above , you need to immediately put them on yourself and, if necessary, help with this environment. In addition, throughout the entire flight, you need to be fastened while sitting in armchairs, which can save you from serious injuries both in turbulence and in explosive decompression.

Known cases

Despite the fact that the depressurization of the aircraft is an abnormal situation, it happens quite often, but almost always without serious consequences. However, not always everything ends safely.

• In 2011, at the top of the plane that flew from Phoenix to Sacramento, a hole about 1.5 meters in diameter was formed. The liner fell safely, no one was hurt.
• In 2005, north of the Greek Athens due to gradual depressurization, the aircraft lost control and crashed into the mountain. At the same time, 121 people died, including 6 crew members.
• In 1988, an airplane flying over the Hawaiian Islands, there was an instant depressurization, as a result of which one member of the crew was fatally wounded. Despite the significant damage to the shell and the destruction of the structure, the liner landed safely.
• In 2015, 20 minutes before landing at the airport in Moscow, there was a depressurization of the Samara-Moscow airplane. No harm done.

Obviously, decompression itself is not so terrible. Everything depends on the reasonable actions of people, however, as usual. So do not neglect the instructions of the crew, especially when they call to be fastened during the flight to the chair.