First you have to get the quest On_Ruby_Wings and you get an item called the Ruby Beacon of the Dragon Queen.
This item is supposed to let you only fly in the area near Wyrmrest, but if you don't turn in the quest and fly out of the zone you will get a 10 second countdown and most of the time afterward, you aren't ejected from the mount.
This makes questing in the rest of the zone VERY quick considering it's an epic flying mount speed and you can avoid aggro with it.
Note: I suggest flying low to the ground, in case you are ejected and don't want to die a painful falling death.
by TooSlo