It's their airfield - if they post the conditions properly you have to abide by them, including wearing a silly jacket - but the keyword is
properly. There are several cases concerning car parks where this has not been done and they haven't had a leg to stand on, so this is where I would look if it escalates.
Check out the magistrates court rules as well - they used to have to do something about it within 3 months. But it's years since I dealt with this sort of stuff, but parabellum makes a good point about insurers who do not live in the real world
"So all in all, is the EEC, is the European Union a good thing for Europe and the UK? Are you better off than you were in the 90s or the 80s, or just more headaches to deal with? Do the collective governments know you and what is best for you, better than you know yourselves?"
Non.
Phil