Travel puts you in close contact with engineering you normally never think about. An aircraft cabin is a pressure vessel, and many of the little features you notice from your seat follow from that one fact.
These oddities explain the details you can see from a passenger's point of view, the reason each one exists, and what would happen without it. We lean on regulators and manufacturers for the technical parts and point out where popular explanations go wrong.
Travel
The tiny hole is a breather or vent hole in the middle pane of a cabin window. It lets cabin air into the gap behind that pane, so the outer pane carries the pressure difference while the middle pane stays unloaded as a backup, ready if the outer one fails. The pane you can touch is only a scratch guard.
New Shorts explain one everyday object in under a minute. Subscribe on YouTube so the next one finds you.
