I live 5 minutes down the road and I'm wondering the same thing
I've never been able to find anywhere good to watch the Reds from really (with the exception of my garden

).
Being on a slight hill, where ever you stand you're obstructed by something.
If there's room I think we'll go to the little car park viewing area, if not then the the viewing area just off Till Bridge Lane and the road into the village of Scampton. And walk up to the end of the runway.
I haven't seen where the flypast will fly though. So I'm stumped.