I had that sort of happen, whereby I was standing on the wings of my warhawk capturing a base, and someone sneaked up and literally hijacked my hawk from beneath me. He took off, and for a second or two I was still on the wings before falling off. It would be interesting to see how long you could stay on them in a more controlled experiment, though (i.e. where the flyer just hovers up vertically).
I've seen some interesting warhawk-related stuff lately..like in the destroyed city map, seeing people try to land their warhawks on the top of the towers, sometimes succeeding, and occasionally seeing their warhawks hangin onto the edges of tower by their front landing wheel