When flying, many people prefer window seats so they can enjoy the view outside. You can watch through the window while the plane takes off and lands, taxis, and soars into the clouds as the city grows smaller behind you. However, have you noticed that there is one unique feature of airplane windows compared to regular windows?
Airplane windows are round! If you don’t stop to think about it, it’s easy to overlook that small detail, but it is interesting to explore. Unlike ordinary rectangular windows, why are airplane windows round? We’ll be finding out the answer through our 14th edition of Aviation Fun Facts: Why are airplane windows round? 🤗
Airplane Windows Were Originally Rectangular! 🛩

In order to understand why airplane windows are round in shape, we need to look back at the first passenger plane. The world’s first commercial jetliner was the British DH-106 Comet, which flew from 1949 to 1964. The Comet was the first state-of-the-art, pressurized commercial jetliner, elevating the travel experience. 🛩
The Comet was a passenger plane seating only 42 people on board, but able to move twice as fast as planes before it, thanks to a newly developed jet engine. It also raised the flying altitude to 40,000 feet, avoiding turbulence, allowing for a more comfortable flight. However, the Comet would crash in flight, one after another, causing a number of casualties and dampening its popularity.
An investigation committee was created due to these repeated accidents, and it discovered the reason for the crashes. Surprisingly, the reason was that the airplane windows were square! 😨 Plane accidents were happening because of the shapes of the windows! It’s hard to make the connection. Let’s unpack this, shall we?
Why Round Windows are Safer When in the Air ☺

The reason for the accidents was due to something called “metal fatigue”! Metal fatigue refers to a phenomenon where the wear and tear from the impact on an object accumulates over time, eventually destroying that object. One example of metal fatigue is when a small crack causes a dam to eventually break down over time.
Aircrafts are constantly exposed to shocks while flying. Typically, there is metal fatigue caused by a difference in atmospheric pressure. The higher the altitude, the lower the air pressure, and the difference in air pressure causes metal fatigue on the aircraft. In addition, impact, engine vibrations, and air friction that occur during takeoff and landing are factors that add to metal fatigue.
In the case of the Comet, metal fatigue occurred in the form of cracks in the corners of the relatively less durable square windows, which resulted in tragic accidents. 😥
That’s how the round windows we know today came to be! Round windows started to be installed on aircrafts, in addition to other safety measures, such as creating triple-layered windows to increase durability and drilling small holes in the windows to reduce fatigue caused by pressure differences.
In addition, guidelines for accident prevention caused by metal fatigue were strengthened. Each airplane part is created to show hours of usage and the number of take-offs and landings completed to help prevent accidents. So don’t worry! You can fly with peace of mind. ✈
The 14th edition of Aviation Fun Facts was about why airplane windows are round. What did you think? Did you find it interesting? It’s something you probably never thought of before, but fun to know!
Incheon Airport will be back to share more fresh and interesting stories, so check back in soon! ✈