The dragon's flight is not physical — it is metaphysical. A dragon does not fly by beating wings against air, as birds do. Instead, the dragon flies by riding the currents of qi — the vital energy that flows through all things.
This is why dragons are depicted winding through clouds, not flapping through them. The dragon's body is a vessel for the movement of qi, and where qi flows, the dragon may go. This is also why dragons are associated with water — water and qi share the same fundamental nature.
In the great dragon flights of the Tang Dynasty, observers reported seeing dragons that appeared and disappeared between breaths, that were simultaneously in the sky and reflected in the river below — because they were not in any one place at all.
Some scholars believe the dragon's flight is a metaphor for the enlightened mind. To fly like a dragon is to move through the world without resistance, to be everywhere and nowhere, to observe without being observed.