This one is for all those people who’ve craned their necks to get a good view out of a plane window while wondering why they are made so small. There are some very scientific reasons why plane windows are so small; and there is also a very sound reason why they have that small hole in there.
Wouldn’t it be better to have bigger windows?
They tell us to keep the window shades open for takeoff and landing so passengers can see and report anything untoward such as smoke, fire, a wing or engine anomaly etc., so why not have big windows? We can see better and this would also perhaps stave off the claustrophobia that many people associate with airplanes.
Aircraft windows are kept small in order to strengthen the hull or the frame of the plane. The larger the area between the windows, the stronger is the aircraft. In fact the air frame would be strongest if there weren’t any windows at all. Since windows are necessary in passenger aircrafts, they are kept small and the area between them kept wider. Larger windows are seen to cause metal fatigue and result in high altitude ruptures.
Also in case of a blowout, the passenger next to a window could get sucked out and the cabin could quickly depressurize; another reason for windows being smaller. In recent times though, with newer materials and construction techniques it is possible to have bigger windows in aircraft such as the Dreamliner or the Boeing 787. In fact soon we could have no windows at all; proposed supersonic jets could have those windows replaced by video screens that show the outside vista.
Why do windows have those small holes in them?
Apart from the awe that some of us feel at the magnificence of the earth spread out below us as we soar above the clouds, the rather prosaic question about that little hole in the window has consistently nagged at many of us. The aircraft window consist of three panes and it is the middle pane that has that little hole typically. It is there to act as a ‘bleed valve’ to let the pressure between the panes to remain constant. The outer pane is the strongest and takes all the pressure; but in the event it cracks, that middle pane acts as a fail-safe. The little hole also releases moisture so that the windows won’t get fogged over.
And why are the windows round?
The answer to that burning question is that square windows are prone to falling apart in the air because the corners create weak spots that are far likelier to crack than curved windows. With curved windows, the pressure is more evenly distributed and the windows are less likely to crack.