I dunno. Ten, fifteen? But it has to be there. The rest of it requires another £100,000 worth of fuel for the aircrew to make pass... after pass... after pass over the camera position. It's genuinely quite tricksy to follow aircraft, I've done a bit of it.
The depressing thing about TV ads is that you generally end up paying about £500,000 to Scaatchi, Scaatchi, Scaatchi, Scaatchi and Scaatchi, or some other such useless bunch of, eh, consultant type people, then you get to spend about £1.50 producing the thing.
-P