We are playing in a high-level message-board campaign, and my friend have a Rogue/Dragonfire Adept (level 2/level 16). We are currently facing two adult white dragons. My friend is arborn, hidden & invisible, and is behind an equally invisible, airborn white (we both can see invisible - I'm playing a warlock). Now, he first plan to do an entangling exhalation (fire breath) on the dragon, then follow it up with a slow breath on the next round. Now, dragons are by nature fast flyers, but they are not very agile in the air. If he hit both attacks (and he should, as he have a flight speed of 80, perfect manueverability), that should cause the dragon to slow down to a quarter of its normal speed.
My question is: Will the dragon still be able to fly while it's under both breath effects? I would figure gliding would be the best it could hope to do, but I would like to hear more expert views than my own.