Rules: Hover and Wingover

Hovering is a move action, which means a dragon also can use its breath weapon, cast a spell, use a spell-like ability, or make a melee attack while hovering (but not with a wing or its tail).
If a dragon does not attack during a round when it hovers, it can instead move at half speed it any direction it likes, including straight up, straight down, or backward, no matter what its maneuverability rating is.
When a dragon stops hovering, it can turn in place and resume ordinary flight in any direction in which it could normally fly. For example, if a dragon were flying north when it stopped to hover, it could turn around and fly south afterward. It still could not fly straight up or down or fly in any other manner that its maneuverability rating does not allow.
A dragon can perform a wingover as a free action while flying. Performing a wingover consumes 10 feet of flying movement. A dragon cannot hover or gain altitude in the same round that it performs a wingover.