The Unexpected Purpose Of Those Tiny Holes In Plane Windows

After you've done plenty of reading and streaming, there usually comes a point on your flight in which your gaze saunters over to the window, specifically the tiny little hole at the bottom. At first, you try to touch it before realizing it's on the other side and wonder the obvious: Is that hole supposed to be there? Should you not have booked the window seat? It's perfectly normal, and there's no need to alert the stewardess. That hole is actually making the flight a bit safer by helping to regulate the pressure around the windows.

It's known as a bleed hole, and its role is to help ease the pressure on the windows as the plane climbs thousands of feet, especially in the case of an emergency with rapid changes in pressure. The windows are, in essence, one of the weakest spots on the plane's fuselage, but since people obviously would prefer not to be in a windowless steel tube, they're designed to withstand extreme conditions, and that little hole is part of it.

The reason you can't feel that bleed hole is because the plane window actually consists of three layers of stretched acrylic: the outer pane to withstand the harsh conditions of pressure changes, the middle one to act as a secondary barrier in case the outer fails, and the one you can touch called the scratch pane. Since the air pressure inside the cabin is regulated, the bleed hole located on the middle pane helps regulate the pressure between the outer and inner window layers.

It's most useful in scenarios where the plane suddenly descends, helping to alleviate the exertion of pressure on the outer pane, which might otherwise crack or shatter without it. But it's not only there for safety reasons; it also helps with the view.

Bleed holes also release moisture from the space between window panes and prevent the window from fogging up, so you can get your money's worth and be able to see the beautiful views outside, assuming it's not cloudy. Who knew such a little hole in acrylic could do so much? The stranger sitting next to you in the aisle seat would probably love to hear all about it.