RUMBLETiGER
Adventurer
Double Fly speed?Don't forget to double the fly speed, since the thing is probably making double moves.
I like the idea of the item having a few charges, like....3-4, and they recharge, but only after say, 3 days of continuous non-use, then at a rate of 1/day. That way, you have built-in stopover encounter points. Sorta like having to stop to get gas and getting attacked by hillbillies, only...slower.
Eberron has rules for elemental airships.