This is the reason why Airplane Window has this shape
Airplane Window – The windows of airplanes have a specific round shape. Have you ever wondered what’s the reason behind this?
It is common to see cars with rectangular windows but some could have their customized shape for aesthetic purposes. It is also common to see round windows in airplanes. For some, it is just nothing and means nothing specific.
Based on the article in Mental Floss, the round windows in airplanes are not an aesthetic choice. Airplanes used to have square windows. Because of this, they wound up crashing.
In the 1950s, planes would sometimes disintegrate in midair and this was the time when commercial airlines graduated to faster and larger jets. Two of these incidents involved both de Havilland Comets. They fell apart within months of one another in 1954. This killed a total of 56 passengers.
When the investigation happened, it was traced that the flaw was pointed to the squared-off corners of windows. This collects the stress of a pressurized cabin and can be prone to fracture.
70 percent of the airplane’s stress was concentrated on the window’s sharp angles. This was found out by the Royal Aircraft Establishment when a test happened.
Circular or round windows disperse that pressure more evenly. This became the new standard in passenger aviation. In this, there are actually three panes at work. One pane bears the burden of pressurization while another inner pane acts as a failsafe in case the outer pane fails, although this is rare. Then, one “scratcher” pane. This faces the occupant. (This can allow you to smudge and dirty it up to your heart’s content.)
Have you noticed that little hole at the bottom? This was put there as part of the airplane window to make sure the working pane takes the brunt of the air pressure. This can maintain the emergency pane for “emergencies.”