Ask an Explainer
How do we get breathing air in an airplane? Wouldn't all those people in such a closed space breathe up all the good air?
When a jet engine sucks in air to mix with the fuel, it also sucks in air for the rest of the plane. Outside air mixes with the air already inside and is filtered before you breathe it again. The air is so well filtered, in fact, that 99,98% of all germs are eradicated - that's better than the air you get in a classroom!