Interesting Facts on Airplane windows
We’ve had the pleasure of boarding an airplane and experience the thrill of the take off while we witness the people, cars and building slowly shrink in size and disappear as we ascend into the clouds. But have you ever wondered why are the airplane windows round in shape and have a little hole at it’s bottom?
Though it may seem like a simple window, but the rounded airplane windows design is one of the crucial safety features of an aircraft, perhaps more important than your seat-belt and that life-jacket that you hope never to reach for.
A passenger airplane flies over 30,000 feet and at that altitude the air pressure is very low, which might cause severe health complications. To handle this sudden change in air pressure, the pilot turns a knob to maintain a steady air pressure inside the cabin.
The metal body of the airplane can easily endure this stress, but it’s the airplane windows that pose a bit of a problem. The stress tends to build up and concentrate towards the edges and due to that surfaces with sharp corners crack easily. But with rounded corners, the force is evenly distributed across the pane, making airplane windows virtually shatter-proof.
This lesson in physics was learned the hard way at the start of the jet-age. The de Havilland Comet, the first commercial airplane was designed with square windows. In 1954, two years into service, a flight carrying 26 passengers and nine crew members crashed shortly after taking off from Rome. Two years later, another airplane met the same fate. In both cases, it was metal fatigue around the windows that ripped the fuselage mid-air.
That was history. The modern airplane windows are designed in a three-layer structure: a convex external window pane shielded by a middle layer buffered by an acrylic screen, which is what you smudge your nose against. There’s also a tiny pinhole in the middle layer, which releases some of the cabin pressure on to the outermost pane. This ensures that if the pressure gets too much to handle, it is the outermost window that will crack, and the middle layer will act as a buffer, ensuring you return to ground as planned.
Have a Safe Flight!