Know why airplanes have round windows instead of square ones

New Delhi: Most of us fight for occupying a window seat while travelling on a flight. We love watching the sky from the airplane’s round windows. But have we ever wondered why the plane’s windows are round in shape, not regular squares? Do they to do something with safety? Let’s explore!

As per the how stuff works website, the window seats of planes were square in shape until the 1950s. As flying slowly became popular among people, airlines began to fly at higher altitudes owing to cost-cutting purposes.

To make planes fly at higher altitudes, they had to be increasingly pressurised. Pressure differences between the inside and outside of the plane increased, which further caused more stress. This proved to be dangerous on two occasions leading to massive tragedies in 1953 and 1954 when commercial airliners (de Havilland Comets, the first jet airliner) disintegrated midair. De Havilland Comets’ last flight was in September 1981.

The square windows of the flights were the reasons behind the tragic events. Thereby, these prompted the engineers to think of window designs with a fresh perspective.

Engineers found that owing to the sharp edges of square windows, natural weak spots were created which led to metal fatigue failure. The weakening of these corners was further increased by air pressure at high altitudes.

Due to the weakening of these corners, square windows broke apart from pressure. Thus, the engineers made round windows that distribute pressure evenly as they have no corners for stress to concentrate. It reduces the eventuality of cracks. Besides, circular shapes are more resistant to the repeated pressure differences between the inside and outside of aircraft.

Similarly, there are bleed holes to keep air pressure constant onboard.