Those are just window covers, the tiny hole lets pressure in and out.
I've noticed that airplane windows have a tiny hole near the bottom, and I've always wondered what it's for. Is it there for safety, air pressure, or something else? I'd love an explanation that's easy to understand.
Those are just window covers, the tiny hole lets pressure in and out.
The plate that has the hole in it is a non-structural plastic layer. The actual 2 glass layers of the window are outside of that. They're the ones that withstand the pressure difference between the inside and outside of the airplane. The hole is there to allow the pressure to equalize pressure on both sides of that non-structural plastic layer.
The hole is in the middle structural layer, not the plastic dust cover.
The outer plane window is the important structural one. The inner plane window is to protect the outer one from passengers and dirt etc, and the hole in the inner one is to equalize pressure between the two, so theres not a higher pressure inside that gap.
There's 2 layers, a relatively cheap to replace inner pane and a much stronger outer pane. The hole in the inner pane is there so the air between the two panes can enter and exit so the space doesn't get pressurized.
And when they get sucked out of the plane, do they crash through the inner pane, or is it sucked out also?
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The hole is in the inner plastic layer, not the actual glass windows
The inner plastic “window” is non-structural. The hole allows air to move between the cabin and the outer glass, which helps prevent condensation (moist cabin air against the colder glass) and pressure differences.
Side question - it’s aesthetically better to have a window to see out of, but from a structural engineering perspective, wouldn’t it be better to have no windows at all?
Windows let you inspect the wings during flight if things get weird and let know know if it's safe for emergency egress on that side / end of the plane after emergency landing.
Yes. Cargo airplanes generally don't have windows. When a passenger airplane is converted to transport cargo, they usually replace the windows with plugs too save weight.
Airplane windows have multiple layers. The outer one is structural and keeps the air pressure inside the cabin. The middle one is a backup, the inner one is there to prevent you from scratching or touching the main windows. The inside one you are talking about has a bleed hole to allow air pressure to equalize between the layers and prevent condensation from building up.
There are three layers on a standard commercial airplane window. The one closest to the inside of the plane is a plastic dust cover which helps to keep people from touching the glass structural windows. The outside layer is glass, and helps keep the plane pressurized, so there is a lot of force on that window. The middle pane is there as a backup, and the little hole is there for a few reasons. It helps to avoid condensation build up (fogging) in between the glass panes, but also keeps all the pressure on the outer window so if it has any problems, it will be very evident. If the outer window glass did fail, the hole is still small enough that while air would rush through, it’s not going to cause the same amount of and issue as if it was a whole window that broke.
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