NEXT as you fly in the window seat, take a closer look and you might spot a small hole in the pane of glass.
But don’t panic – it’s not only normal, but without them, big problems can happen.
The strange design helps the aircraft withstand the changing air pressure outside.
Although it may look like there is a hole, the small gap does not go through the entire frame.
Each window is made up of three different layers of acrylic and only the middle layer has air holes.
The small opening helps to regulate the high-pressure environment on the plane, providing a much more comfortable experience for passengers.
Pilot Mark Vanhoenacker previously revealed: “The two exterior cabin windows are designed to accommodate the pressure difference between the cabin and the sky.
“Both the middle plate and the outer plate are strong enough to withstand the dislocation on their own, but under normal circumstances the outer plate is subject to this pressure — thanks to the air vent.”
In addition to being important to the safety of passengers, air vents have another important function.
The small opening allows moisture to escape from the plane, preventing fog from forming on the windows
It is not the only weird thing you can spot on a plane.
Astute passengers may notice small black triangles on the side of their planes.
These indicate the position from which the staff can best see the wing from inside the aircraft.
Everything you need to know before boarding
They can then quickly check the position of the wings or sliders if required from the appropriate window.
There are also little yellow hooks on the wings helps personnel evacuate over the wing and is used to secure and fasten liferafts to aircraft.
Passengers traverse the wing using ropes attached to hooks in the event of an emergency.
https://www.thesun.ie/travel/8183673/plane-window-holes-explained-secret/ Small holes in all airplane windows