particularly if there's a decent proportion of clover in the grass, which most playing fields should have
You
must be joking! You evidently haven't seen the army of staff and the arsenal of chemicals used to maintain a 100% grass surface. Trust me, it's better than most bowling greens...
It's that kind of school. Imagine acres and acres of perfectly flat, perfectly mown grass, and you can see why I want to put an aircraft onto it. Particularly as they've just built a new pavilion which is the spitting image of a control tower (indeed the pupils are already calling it that... not that I've been encouraging them!)
Tim
(to those who are worried - yes, I've flown from grass - see my thread about Weybourne for example!)