Moreover, it'll be kinda hard to miss when Air Force One is landing at an airport. And people will be watching every airport in range to try and spot it.
Edit: Just occurred to me, wouldn't this mean him technically snubbing, you know, Her Majesty and her government if he's visiting just his golf course?
He'll be able to get off Air Force one and to whatever location he's visiting, but I guarantee by the time he goes outside again there will be protestors