the messerschmitts were active units of the spanish air force and were flown by spanish air force pilots .
the spitfires were drawn worldwide from collectors and flown by their owners , as there werent many of them they had to be shot in multiple shoots to give the impression of more than there were.
because a lot of the footage was over england , they coulnt shoot the downward shots of the dogfights in Spain because of the dry countryside , only skyward shots.
for downward shots they had to fly to england. apparently there was one incident where when flying to england for the greenery ground shots , they flew a heinkel bomber swastikas and all, over France and freaked the bejeezus out of the French...lol
