Blues&twos,
Hi there,
I can help you with Gatwick -
You certainly wouldn't be allowed to 'sit on the fence' as you put it these days in current security climate
However, many spotters find the best place most of the time is the 26L theshold (most of time Gatwick is on 26L) and they usually stand/sit along 'Perimeter Road East' just down from the South Terminal. I have done this myself and have never had any bother from police or BAA security. Just make sure you do NOT get too close to the actual perimeter fence because I have a copy of the BAA By-laws and apparently you must get no closer than 3 metres to the restricted zone fence at any time.
For a quick glance across the whole or most of the airport hop onto the BA transit inter-terminal train. Completely free and runs alongside the northern perimetre road and can see most of the stands of the South Terminal satellite possibly more and control tower/parts of North Terminal.
I would suggest you get a train to Gatwick as you will be very hastily moved on by security if you park along the perimeter roads as they are very busy.
I know another location if you would like to know, probably the best for summer and easiest to park at and be prepared for a long walk
PM me for details....
