Why is there a Tiny Hole on the Windows of an Airplane?
If you’ve sat at the window seat of an aircraft, you may have noticed the small hole at the bottom of the window. If cabins are pressurized to keep us from passing out, why is there a hole in every window, you may wonder? Airplane windows actually have three layers.
The outermost one deals with the air pressure difference between the inside and the atmosphere. The hole that you see is called a “bleed hole” and it’s in the middle layer and it helps reduce the pressure on the middle pane. It also keeps the window panes from fogging up so you can take all those awesome Instaworthy pictures!