I heard that if Gravity is used, all flying-types, levitating Pokemon, and all using Fly, bounce, etc. are brought down, and certain moves aren't allowed for 3 turns.
Now this is a scenario between a Foretress and an Aerodactyl.
Aerodactyl used Fly!
Fortetress used (a random move)!
Foretress used Gravity!
(This is where Fly is supposed to hit, but what happens here?)