I call it 255 feet long (and, um, 5 inches) and about the same for wingspan.
What made you think to ask this question? There really isn’t an answer to it. It’s as big as the animators wanted it to be.
(Escaflowne is a surprisingly good fantasy anime series that works for adult anime watchers, though I haven’t watched it in years. The movie is not so good despite some great visuals. )
How big’s Escaflowne? When they’re having the big fight with Dilandau’s lot it could quite comfortably stand on the top, and Escaflowne’s quite big. I don’t know what that proves, if anything. I would go check my DVDs, which have little fact files in the inner sleeve (I’m sure I remember seeing some kind of stats for the Crusade), but I’ve lent them out and don’t know when I’ll be able to get hold of them again.
Heck, someone’s already built Harlock’s Arcadia. I thought it might be fun to try building something along the same lines, from an anime series I adore.