My teacher, when i did a Movie production design course at Pinewood studios, worked on The Battle of Britain as a designer. He has a remotley controlled Me 109 fighter in his office used to film some of the battle sequences.
The Film was a mix of live action and remote model work.
The big hangar that got blown up was going to be demolished anyway so the engineers timed their demolition charges with the 'bomb' detonations to make it look like it was really under attack.
Couple of bits of trivia for ya!