I once made a thread on all the Cids.
But to cut it down briefly:
FFII: An airship pilot. He ownes one of the few airships that aren't under the control of the empire, although it's not sure if he created the airship.
FFIII: Owner and creator of the airship.
FFIV: An engineer, but doesn't own airships, although throughout the game you'll see that he can fly with an airship.
FFV: Cid helps the party to discover an ancient airship, but he himself is an inventor, and hasn't got any great knowledge on airships in general.
FFVI: Chief researcher in Magitek, though you could asssume he helped the empire in the creation of airvessels.
FFVII: Airship owner and pilot.
FFVIII: The headmaster of Balamb Garden, which you could see as an airship.
FFIX: Airship designer.
FFX: Repaired the airship found near Baaj Temple.
