What is aircraft depressurization?

2024 Author: Henry Conors | [email protected]. Last modified: 2024-02-12 02:55

Even those who are perfectly familiar with the laws of physics and understand how it happens that a pile of metal rises into the air, sometimes they still feel discomfort, thinking in flight that there are 10 kilometers between them and solid ground. What can we say about ordinary people? Ordinary passengers are frightened even by the words "aircraft cabin depressurization", not fully understanding what it is and what it threatens.

In flight

Cynics joke that you should not be afraid of planes, because each of them returns to earth in one way or another. If you think about it, only desperate daredevils can voluntarily climb inside a fragile structure that will rise 10-14 kilometers above the surface of the planet to deliver them to their destination. In fact, as statistics show, dying during a flight is not an easy task.

Yes, something out of the ordinary can happen. Nevertheless, modern airliners and their pilots are adequately prepared for many emergencies that in the past led to tragedies withnumerous victims, and now they are just an excuse to make an emergency landing. All automatic systems are duplicated, excluding the human factor as much as possible. If the equipment fails, experienced pilots can often still prevent a disaster or minimize its consequences. And yet sometimes trouble can not be avoided. What happens when an aircraft depressurizes? Is it possible to survive and what to do?

Aircraft depressurization

At an altitude of 10,000 meters, the pressure is much lower than on the earth's surface. It is also much colder there, there is not enough oxygen for the normal functioning of the human body. Needless to say, even the very idea of a hole in the skin can scare even the most experienced and calm passenger? Modern cinema has sacrificed common sense for entertainment, and among ordinary people there is an opinion that even a tiny hole in the shell of an aircraft, not provided for by its design, will surely lead to the death of everyone on board. In fact, everything is exactly the opposite - of course, damage to the skin cannot be attributed to a completely normal situation, but it is completely unnecessary to consider this as a disaster. History knows many cases when even sufficiently large holes in the hull did not interfere with the smooth completion of the flight. So, it's worth understanding what is meant by the term "aircraft depressurization" and what it means in practice.

Reasons

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

• human factor - the actions of passengers or crew that led to damage to the skin;
• manufacturing defects - defective parts, violation of assembly technology, etc.;
• damage by foreign objects - intentional or accidental penetration of the structure by various means from the outside;
• an emergency situation - 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 in completely different ways.

What's going on?

Depressurization of an aircraft at altitude, first of all, threatens passengers with oxygen starvation and the so-called decompression sickness, or decompression sickness. Contrary to numerous disaster films, those inside an airliner are unlikely to be thrown out unless they are strapped in according to crew instructions and a huge hole is not in their immediate vicinity.

In real life, with relatively minor damage to the skin, the aircraft is able to maintain the overall integrity of the structure, so that if explosive decompression does not occur, instantly injuring people and leading to rapidhypoxia, the situation can be called quite controllable. The main thing is to notice a drop in pressure and a decrease in oxygen levels in time to prevent a loss of consciousness in everyone who is in the cabin and, accordingly, a complete loss of control.

Consequences

If the depressurization of the aircraft did not inflict physical injuries on anyone in the first seconds, this does not mean that there is no danger. If no action is taken, all passengers and crew are still at risk from the following factors:

• low temperature - can lead to frostbite, general hypothermia, death;
• caisson disease - damage to blood vessels due to rapid pressure drop;
• altitude hypoxia - insufficient amount of oxygen in the air;

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

Safety measures

Not the last role in how the depressurization of the aircraft ends is how carefully the pre-flight preparation of both the aircraft itself and its crew is carried out. A fairly wide range of factors play an important role: proper operation, thoughtful design, timely maintenance, regular checksetc.

Modern airliners are equipped with a large number of systems that constantly monitor the state of the aircraft throughout the entire flight. With proper experience, pilots will notice even minor problems in time and take the necessary measures to prevent negative consequences. Well, 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 that are automatically ejected over the seats during emergency decompression. Their work is demonstrated by flight attendants at the beginning of each flight during a safety talk. But that's not all.

Crew actions

The most serious problem with rapid depressurization is an acute lack of oxygen, which makes breathing quicker and the head spinning from acute hypoxia. After a few seconds, a person loses consciousness, and after a while, irreversible processes of dying of brain cells begin, so it is extremely important that the right actions be taken in the first moments.

Having discovered damage to the skin, pilots must descend to a safe height of 3-4 kilometers in the shortest possible time. At this level, there is enough oxygen to support the life and relatively normal functioning of the human body.

After the situation has stabilized, it is necessary to assesssituation and decide on an emergency landing at the nearest available airport. Depressurization of the aircraft is enough reason to stop the flight, since there is no guarantee that the destruction will not continue.

Passenger actions

It is very important how ordinary people will behave when faced with decompression. First, it is necessary to remain as calm as possible and not to escalate panic. Secondly, you need to carefully listen to the instructions of the staff and follow them. If oxygen masks fall from above, you should immediately put them on yourself and, if necessary, help those around you with this. In addition, seat belts must be worn throughout the flight, which can prevent serious injury in both turbulence and explosive decompression.

Known Cases

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

• In 2011, a hole about 1.5 meters in diameter formed in the top of a plane flying from Phoenix to Sacramento. The liner descended safely, no one was hurt.
• In 2005, north of Athens, Greece, due to gradual depressurization, an aircraft lost control and crashed into a mountain. This killed 121 people, including 6 crew members.
• In 1988, in an airplane flying over the Hawaiian Islands, an accident occurredinstant depressurization, as a result of which one crew member was fatally injured. Despite significant damage to the skin and the destruction of the structure, the liner landed safely.
• In 2015, 20 minutes before landing at the capital's airport, the Samara-Moscow plane depressurized. No one was hurt.

Obviously, decompression itself isn't that bad. It all depends on the reasonable actions of people, however, as usual. So don't disregard the instructions of the crew, especially when they call for seat belts during the flight.