|Image courtesy Royal Air Force|
No, not this - though a Short Sunderland is in fact magnificent. I mean wooden ships floating through the air in much the same way that bricks don't. It's not exactly original - if legends of the Flying Dutchman are authentic, the trope is older than steam. I'd say it's definitely older than radio, since the first real airship flew in 1852: http://en.wikipedia.org/wiki/Giffard_dirigible
I like the idea because it is, of course, entirely impossible. Which is what fantasy gaming should be about. I'd like to keep them just like real boats for aesthetic reasons. No gasbag fig leaf where the sails should be, and no on demand performance like some sort of magic helicopter. I want them to drift inconveniently and roll precariously, with a top speed you could expect from sail and a rate of climb that wouldn't startle a balloonist. These limits still leave a lot of possibilities:
Fantasy bomber: You know darned good and well that the first thing primates with a height advantage want to do is start dropping stuff. I'm going to make some excuse about hull integrity to avoid having bomb bays and keep folks from trying to land on someone else's mast, but pretty much anything you can heave over the side should hit the ground unless there's a really good excuse.
Paratroopers: I don't like the magic-as-tech thing of handing out featherfall rings, but the first parachutes were deployed more or less right after the first aircraft (first recorded jump in 1783). People with aircraft want a way to get out of them when things turn pear-shaped. Besides, I find the concept of Viking paratroopers to be hilarious.
Carrier: So I played a few too many games of Joust. It seems like a great idea to have saddle-trained enormous birds or small dragons perched in the rigging to everyone except for the poor zlotnik that has to swab the deck. Look here for the real version: http://en.wikipedia.org/wiki/USS_Macon_(ZRS-5)
Kedging: One advantage to an air boat is that if the wind fails, you can just grab a mooring line and pull the silly thing. Until the wind picks back up. Which it may do without warning. Which means you can very quickly go from desperately needing to drop the rope to desperately needing to hold on. Have fun.