Basil
I'm not seeking to ban people from their own gardens, but if you've been to an airshow recently you will no doubt have seen people watching from just outside the show gates, or in adjacent fields.
Indeed some of the shocking video footage from this incident has been provided by people doing just that (from very close to or on the A27 in some instances).
You are in far more danger watching shows from such vantage points and proverbial 'naughty Fields' under the display line on many occasions, than you are inside the official showground, where distance rules separate you from the display lines for your own safety?