Proving a negative is hard. I have been reading several pages from the Rules Compendium, but information about combat advantage is very scattered.
I'm specifically interested in flying, but if it's a more general rule that applies, that's OK.
The flying speed description and the general combat advantage rules don't name it.
No.
Flanking is the only “automatic” way to gain combat advantage. Other than flanking and the per-encounter Bluff check to trick an opponent (Rules Compendium page 218), the most common way to gain combat advantage is when a power explicitly grants it.
The ability of a ranged attacker to fire at a melee target who cannot otherwise strike back is already quite an advantage.
