Some of my radios have the AIR band. I had never picked up an aircraft or
tower. How does one monitor the AIR band?

Sometimes I'll heard strange signals that may sound like a fax. But I am
not sure what that is.

Is there an AIR frequency list around?

Now on the Marine band I do pick up boats. Well I live near a river. But
should an aircraft fly over my area and I am on it's frequency and a
transmission came out from it, well, because of the speed of the aircraft, I
am not too sure how long it would last.

Boats are much slower. And better for this I think!

73