Dragonwings is the name that Windrider and Moon Shadow give to their first full-sized airplane that they test out in Chapter 12. But the theme of dragons throughout the novel is significant for more reasons than just the airplane alone. Before the Lees even hear of the Wright brothers, Windrider has an epic dream about meeting the Dragon King and being told that he was a dragon in a former life. Moon Shadow is the only person Windrider shares this dream with who actually believes in him; the rest of the Company, Uncle Bright Star especially, thinks Windrider is crazy.
Windrider aspires to be a dragon once more. The Dragon King told him that he would be tested as a human, and how he performs on these tests determines whether or not he will be granted dragon form again. To use dragon wings, then, seems to be a question of how much a person can rise to the challenges set before him. Moon Shadow gauges the kind of person he wants to be according to how dragonish the behavior is. For example, when he leaves the stable to "take a walk," he feels a dragon's courage in preparing to stand up to Jack and the other neighborhood bullies.
The title "Dragonwings," then, speaks to the larger metaphor of flight. Sure, Windrider is obsessed with airplanes and the idea of flying, as in literally soaring through the air. But what of another type of flight, one where you might feel like you're soaring through the air, but your feet are still on the ground? What of putting in the mental and physical work, of building up courage and facing your fears? If you've ever felt that lump in your throat because you were experiencing something you knew to be special, then maybe that's a type of flight, too. The book seems to ask, what other kinds of flight are there? And which forms might wings take?