Not sure if this is to be applauded or warned against !
http://www.youtube.com/watch?v=GWXUP1FHufs (1:40 has the interesting part).
Like 'Drifting' in car racing! I guess the plane hit a micro burst and suddenly lost lift. Great reflexes on Ali's part. But as I maintain in the 'Amir Vs Heli' thread here, such things should be avoided close to people..