Although this is perhaps one of the most watched aviation videos in history, it's appropriate to put it up again as a tribute to a great pilot who died this week. This is Bob Hoover pouring iced tea as he performs a barrel roll and spills not one drop. Who said water doesn't flow away from the centre of the earth? It's all about keeping positive g in the roll, and no person ever did it better than Bob. It's old and grainy footage, but you can still see what's happening clearly.