They’re handy for watching the clouds drift past, or if you’re in a coveted window seat, resting your head against in a bid to catch some zzz’s, but have you ever noticed that all plane windows are round?
It might surprise you to learn though, that in the early days of aviation, windows – much like ones we have at home – were square.
So why the change?
Well, as it turns out, there’s a serious safety reason after two de Havilland Comet airliners broke apart mid-flight in the 1950’s, leaving 56 dead.
An investigation later found that cracks had developed in the body of the aircraft near the doors and windows.
Findings found that square windows have corners, with these weak spots making them more likely to crack.
"Sharp corners are natural weak spots where stress concentrates, weakened further by air pressure," explains Travel and Leisure. "When subjected to repeated pressurisation, four corners on a square window spell disaster."
The change to curved windowpanes with no corners saw a reduction in the chances of the window succumbing to the pressure.
So there you have it, something to think about the next time you sit back, relax and stare out of the rounded window.