Carriers are indirect units which can attack air units. Furthermore can air units land on them. Air units landed on Carriers will refuel.
|Unit Classification||Indirect Sea Vehicle|
Air units that are landed on them will instantly refuel. So if you land an air unit on a Carrier and unload it directly afterwards, it is refueled. Furthermore it might be noted that Stealths that are landed in hidden mode, remain in hidden mode when unloaded.