BaT-Off
I think you well qualified the answers you got with your own response.
Too bad, and here I was thinking all along that you are asking about backwards autos, (to the ground) when all along all you wanted to know about was auto-rotational flight, going backwards sideways or any which way. Big bloody deal! Fair dinkum, have ye not got a reverse gear in your motor scooter to play with?
There was an urban myth around about thirty years ago, that one, who used to go by the nick-name Barnacle Bill, used to do-em in a 3B1 up in the oz outback.
He now is i believe a mine host of a hosteliery in Ireland someplace. Now that would be a good spot to drop in for a lemonade as you folks do over there.
Any one knows him drop in and shout him one for me, I owe him one from way back. yeah 1975 I think it was.
tet