WW2: Fighters Fly a bird
Enter the museum and test fly the Spitfire. Drop both of the 500 lb. bombs and expend all ammunition except for approximately nine rounds. Then, press [Ctrl] + A + E to turn off the engine. The Spitfire will now transform into a large bird that is carrying a bomb.
The image featured at the top of this post is ©The Legend of Heroes: Trails of Cold Steel III key art / Original