Yes, those are paper aeroplanes. Yes, they are on the Humanities building roof (well, 2 of them). Yes, I was standing in the Library Group Study room and the second floor when I threw them.
Incidentally, for anyone not already comatose with boredom, the ones on the roof were thrown over the window, and the ones on the ground, which nearly made it – bouncing off about half a metre too low – where thrown under it. So there is your paper aeroplane throwing tip of the day.