Hi Callum,
Congratulations for your luck but don't necessarily expect great acts of flying. I think most of the competitors attempt to build the craziest "thing that has no chance of flying anyway but plunges nicely".
At least this happened in the last 2 years when they organized the same here. Or perhaps in London they spend more effort in making their machines flyable and less to make them funny? Just curious...
Anyway, have fun and drop a line over here to tell how it went!
Andrei