Depressurization is, perhaps, the most popular plot in disaster movies. On-screen heroes battle icy winds and objects flying around the cabin, but in reality, the main danger looks different. It is invisible, silent, and occurs in a matter of seconds.

If you decided to buy tickets from Moscow to Yuzhno-Sakhalinsk or are planning tickets from St. Petersburg to Kaliningrad, know this: modern airplanes are among the safest places on the planet. But safety instructions are not just for show. Let's figure out what actually happens when masks drop and why "selfishness" saves lives at that moment.

What is Depressurization, Really?

At an altitude of 10,000 meters, the air is too thin: it contains critically little oxygen, and the pressure is negligible. To allow you to comfortably read a book or sleep, the aircraft artificially maintains pressure corresponding to a comfortable altitude of about 2,000–2,400 meters above sea level.

Depressurization is a breach of this sealed "envelope." It comes in two types:

1. Explosive (rapid). Occurs instantly. Fog may appear in the cabin (condensation due to a sharp pressure drop), it gets cold, and masks drop from the overhead panels.

2. Slow. The most insidious. Pressure drops gradually. Without special sensors, passengers may not notice anything until they feel drowsiness or dizziness.

Why "Put it on Yourself First"?

The main rule repeated in every briefing: first put the mask on yourself, and then on a child or neighbor. This sounds counterintuitive for any parent, but this rule has a strict biological justification – "time of useful consciousness".

At cruising altitude during rapid depressurization, an adult has only 15 to 30 seconds before the brain begins to shut down due to hypoxia (oxygen starvation).

How it happens:

• You don't feel pain or suffocation.

• Euphoria, sluggishness, or sudden confusion of thought sets in.

• You lose coordination and the ability to perform meaningful actions.

If you spend those precious 20 seconds trying to secure a mask on a frightened child, you risk losing consciousness, failing to help either them or yourself. A child, however, will tolerate a brief lack of oxygen without consequences. A conscious adult can save everyone nearby, but an unconscious adult is, alas, no help to anyone.

How Does an Oxygen Mask Work?

Many are surprised: "Why doesn't the bag on the mask inflate? Is it broken?" Calm down, everything is going according to plan. The bag is just a reservoir; it's not supposed to inflate like a balloon; its purpose is to accumulate oxygen while you exhale.

Passenger aircraft do not have heavy gas cylinders above each seat. Instead, chemical generators are installed.

• When you sharply pull the mask towards you, you pull a pin.

• A chemical reaction starts, during which pure oxygen is released.

• Important point: the generator gets very hot during operation, and you might smell burning. This is normal! Don't be alarmed; it's a sign that the reaction is occurring and you are breathing purified oxygen.

The supply lasts for approximately 12-15 minutes. This time is more than enough for pilots to perform an emergency descent to a safe altitude (around 3,000 meters), where the air is already breathable without equipment.

What to Do if Masks Drop?

1. Don't panic. Panic makes you breathe faster, meaning you consume oxygen in your blood more quickly.

2. Sharply pull the mask towards you. This activates the gas supply.

3. Put it on and secure it. On yourself first! Make sure the mask fits snugly over your nose and mouth.

4. Help others. Only after you have supplied oxygen to your own brain.

5. Stay in your seat and fasten your seatbelt. Pilots will begin a steep descent, so it's important to be securely fastened.

Remember that aviation is a field where rules are written with immense experience. Trust the crew, know the action algorithm, and enjoy your journey. Your awareness is the best contribution to flight safety.