“Breathing Hole” or “vent hole” and is one of the important features of aircraft.

Some people have this hole whether it is risky but on the contrary, it is a technical idea that prevents risks.

Airplane windows consist of three layers: inner, middle and outer.

These layers are often made of acrylic material. The inner layer protects the next layer and the passengers; It’s a plastic cover. As “breathing hole” is in the middle layer. The outer layer is the last layer that can withstand the harsh weather conditions outside the aircraft.

The cabin pressure of a standard airliner is above sea level. 2500 meters is equal to the pressure at altitude (this altitude was recorded up to 1800 meters on advanced aircraft type Boeing 787 and Airbus A350).

As the aircraft gets higher, the pressure outside and inside the cabin begins to decrease. This is the reason for that strange feeling in our ears, we feel the effect of our inner pressure. The pressure outside is of course much lower than the pressure inside the cabin. Here on airplane windows 2nd and 3rd layer interface between this pressure. It is designed to be durable enough to withstand this stark difference.

Let’s get to the important function of the small hole:

This hole is in the cabin with the pressure between the 2nd and 3rd layer. balances the pressure. The main pressure is supported by the outer layer, so that the middle layer is not overloaded. This small hole makes this possible.

As the aircraft ascends to normal cruising altitude, ice crystals begin to form around this hole.

This is because the warm air in the cabin comes into contact with the cold window surface. The moisture that has accumulated between these two layers is drained from the hole and It is ensured that the windows do not fog up and do not freeze. Otherwise it would not be possible to view those beautiful cloudscapes.

But what happens if it bursts and air gets in it?

In such a scenario, the amount of air leaking out of this hole would be very low, so the pressure balancing system will overcome this problem.

Summarized; this little hole that doesn’t look like much It is one of the essential features of aircraft.

Sources: 1, 2