The big sigh of relief after finally getting through security and sitting in your window seat is often followed by the question 'why is there a tiny hole in my window'.
Well, if you're wondering, a former 747 pilot has the answer.
After a long stint flying 747s, TikToker Harrison Murray says he now works at a cargo company based out of Heathrow Airport.
Explaining the holes in the windows, he said: "Aeroplane windows are typically made of three pounds of (stretched) acrylic.
"You've got the outer, you've got the middle where that little hole is, and you've got the inner.
"Now when an aircraft starts gaining altitude, the outside air pressure is constantly decreasing.
"So we need to pressurise our planes. We typically cruise around with a cabin altitude of around 8,000 ft.
"Now the difference in air pressure between the inside of the plane and the outside world is very high.
"And that can cause the window to stress.
"So those little holes (bleed holes) allow the pressure between the inner window and the outer window to balance out."
The pilot's claims are backed up by the The Federal Aviation Administration (FAA) who previously also told Insider that the 'bleed hole' allows the air pressure to balance, as well as preventing the window from fogging up or frosting over.
Now that the kids' summer holidays are well underway, many will be heading the the airport for a much-needed break.
So basically, if your electronic devices aren't fully charged, whether that's your phone, laptop or iPad, they could be taken off you if requested by security.
The UK Government website states: "Make sure your electronic devices are charged before you travel. If your device does not switch on when requested, you will not be allowed to take it onto the aircraft."
British Airways have elaborated on the rule and have said: "You can generally take electric and electronic items in your hand or checked baggage, but need to follow specific safety instructions.
"Airport security staff may ask you to turn on electronic or battery-powered devices, such as phones, tablets, e-books and laptops, to demonstrate their function.
"If you're not able to do this, you will not be able to take your device with you.
"Please ensure that any items in your hand baggage are fully charged and switched on before you arrive at the airport.
"If your device is not charged, please place it in your checked baggage.
"If you are connecting, make sure that you do not deplete power in your devices during the first part of your journey as charging points at airports might be very limited and you may need an adapter."Featured Image Credit: PhotoEdit/Alamy