You can have any combination of features the Air Ministry desires, so long as you do not also require that the resulting airplane fly.

[Natürlich können Sie dem Luftfahrtministerium ein Flugzeug mit allen gewünschten Eigenschaften bauen — solange Sie nicht zwingend voraussetzen, dass es dann auch fliegt.]

Willy Messerschmitt
Wilhelm Emil "Willy" Messerschmitt (1898-1978) German aircraft designer and manufacturer
(Attributed (1934))

Alternate translation:

Of course, you can build the Air Ministry an airplane with whatever characteristics you want -- as long as you don't necessarily expect it to fly.