Ever traveled on a plane and noticed that there is a small hole at the bottom of the window that provides a view outside?
Yes indeed airplanes have a small hole in the windows and this is not done to make them look good but for a different reason.
In fact, these tiny holes help keep people safe.
As altitude increases, the amount of oxygen to breathe decreases, and the lack of oxygen increases the risk of illness or death.
Airplanes usually fly at altitudes of 10,000 feet or more, and at such altitudes it is impossible to breathe without an oxygen mask.
This is why aircraft cabins are specially pressurized so that passengers and crew can breathe normally.
This is done by delivering air from the aircraft engines to the cabin and when the internal pressure of the cabin becomes adequate, the air flow is kept constant.
So this pressure helps protect humans from harm, but it is not useful for planes.
This is why there needs to be a way to release this pressure and that way is the small holes on the windows.
These holes are called bleed holes and these holes maintain balance despite the pressure difference between the cabin and the outside air.
Another purpose of them is to protect the window from moisture so that passengers can see outside.