The tragic reason why airplane windows are round

Two infamous plane crashes led to all plane windows being round. Photo / Killian Pham, Unsplash

Taking in the remarkable views from an aeroplane window, most of us have probably never stopped to wonder why they're always the same oval shape.

As with most things plane-related, this isn't a result of pure chance or aesthetic preference but rather the consequence of two catastrophic plane crashes within months of each other.

In 1952, the de Havilland Comet from Britain became the first scheduled commercial flight with pressurised cabins and turbojet engines allowing it to fly higher and faster than other aircrafts at the time.

Just one year later the Comet was deemed a global success and science and technology magazine 'Popular Mechanics' claimed the UK was now three to five years ahead of other jetliners around the world.

However, on 10 January 1954, flight 781 departed Rome's Ciampino Airport with 35 passengers and crew, bound for London.

The jet flew for approximately 15 minutes before fracturing in the sky and falling into the Mediterranean Sea, leaving no survivors.

Months afterwards, 21 passengers met a similar fate flying from London to Johannesburg on South African Airways flight 201. The recovered bodies showing similar injuries to the head and lung as those on flight 781.

The common factor? Square windows.

Pressure concentrating in the four corners of every window, contributing to metal fatigue, which caused the planes to explosively break in mid-air.

"Rounded corners are designed to help distribute the pressure exerted on the window evenly, reducing the likelihood of a window cracking under changing air pressure," said Willis Orlando, Product Operations Specialist at Scott's Cheap Flights.

After investigations into the crash, de Havilland made several design changes, including rounded windows that allowed stress to flow evenly.

This change was also crucial as aircrafts needed to fly higher and faster to limit unnecessary fuel use and be more cost-effective.

As a result, planes needed to be more pressurised and thus able to handle stress build-up.

Despite the changes, commercial sales for de Havilland's design supposedly never fully recovered.