Hole in aircraft window- Breather Hole

Breather Hole

Window seat of the aircraft is the favourite seat of almost all of us aircraft nerds. Ordinary peoples will just see scenery from aircraft window. But we aircraft nerds observe various things of aircraft such as movement of various elements of aircraft wings such as slits, flaps, ailerons, aircraft engine, etc.

Have you ever taken a look on the small hole at the bottom of aircraft window? If not, then next time whenever you will travel by plane just take a look at that small hole at the bottom of aircraft window.

This small hole is known as breather hole or bleed hole. There are mainly two purposes of this hole

• Controlling moisture
• Equalizing pressure difference

The small air gap is present between outer & middle pane.

This tiny hole lets moisture escape from air gap & prevent aircraft window by fogging up or by frosting. And let passengers enjoy the outer scenery.

As stated breather hole also helps to equalizing pressure difference. As aircraft ascends atmospheric pressure decreases & cabin pressure is maintained by the cabin pressure stabilizer system as outer atmospheric low pressure is not good for human health. This causes a pressure difference between cabin & atmosphere. Which produces lots of physical stress on aircrafts window which can damage aircraft windows. So to prevent this damage breather hole is used. Breather hole equalizes the pressure difference between inner & outer aircraft window pane by releasing some amount of pressure in the air gap. So outer pane takes lots of pressure & middle pane acts as a fail safe. If the outer pane got damaged due to some reason air get leaked from breather hole & prevent middle pane by damaging.

This is why breather hole is used!!

Hope you guys understand the importance of that tiny hole.

Thanks for reading!