Quote Originally Posted by Scarlet Knight View Post
This reminds me, 'cause sometimes I forget, that Phil is a cartoonist, not an author. For plot, Franz could have just flown Agatha into the sky. He's a dragon, has wings, dragons fly, etc. Instead you create a subplot of a non flying dragon just for the chance to draw a dragon powered flying machine!
Flight is not a simple thing. You double the size, you multiply mass by 8. Doubling wing size just doesn't cut it after a while. And Franz is barrel chested even for a dragon, making unassisted flight even less plausible.

On the other hand, of course, you're right: this is done purely for comedic effect.