Why do airplanes have round windows?

Why do airplanes have round windows? Credit: Canva

You may be so used to sitting next to a round window seat on an airplane that its shape has gone completely unnoticed by you. But airplanes Today we have round windowswhich wasn’t always the case. If you had flown before the 1950s, you would have noticed that the windows were square in shape. Why did this change?

Safety first!

airplane windows Windows are round for a reason: they are designed to be safe and strong. The round shape helps distribute pressure over the window, making it less likely to break. This is especially important when the plane is flying high, where the pressure inside is very different from the pressure outside. Square windows and their sharp edges caused “metal fatigue failures” (pressure builds up at sharp corners, causing glass to break and the plane’s body to crack), as seen in three crashes between 1953 and 1954.

Three different aircraft (all De Havilland Comets, the first jet airliner) disintegrated in flight due to stress concentrations caused by the sharp edges of their windows. The cause of these crashes was found to be the windows, so the design of the windows was changed to oval ones. Round windows are easier to reinforce and can better withstand the stresses of flight.

The same logic applies to cargo and cabin doors, and you may have seen circular windows even on ships and spacecraft as well, simply because they offer better structural integrity to the entire structures by evenly distributing pressure build-up.