18:18 Mar 4, 2011 

Just a couple of links:
http://www.thefreelibrary.com/Proxim Wireless and Wi-SKY Net...

With:
"broadband wireless connections between a land-based base station and moving sea and air vessels"

Or a picture here:
http://www.definitions.net/definition/air vessel
Although most are for your definition of air vessel, the fourth one shows ... a plane!

17:46 Mar 4, 2011 

На всякий случай, воздушное судно = aircraft и никак иначе, никаких vessel. Air vessel - это сосуд с воздухом.
Летательный аппарат в подавляющем большинстве случаев переводится как flying machine, а не apparatus.

04:22 Mar 4, 2011 

I should have said: ... can't be called "воздушное судно". Must have had my wires crossed or something (was looking at the header when I wrote that). But the rest still holds.

03:22 Mar 4, 2011 

Please mind, the meaning is: "воздушное судно" [is a kind of] "летательный аппарат", that flyes in the air (or something).

Thus, a space rocket is a "летательный аппарат" (flying apparatus), but is not a "воздушное судно" ([air]vessel).

18:15 Mar 3, 2011 

If you take it at face value, it means that a rocket (or a hypothetical antigrav vessel) can't be called "летательный аппарат".

Consequently, I think you'll need to mention the air somehow. So just "flying" or "aloft" won't do - not unless you combine them with something like "[aloft] in the air"... if it makes sense.