Press T for the message prompt and type:
Code Result
you got what i need Unlimited Ammo
food goes here Reload Plane
big gulp Refuel Plane
youre here forever Invincible
damn that corner No Crashes
chiliburger Repair Plane
spindive Cannot be Hit
upside down Auto Level Fly Upside Down
paperairplane Paper Airplane
water boy Allows Plane to Skim on Water