It's real. Somebody modified a variable pitch gear from an electric helicoptor to work on planes. It's known as 4-D flying. It allows the prop pitch to be reversed so it's possible to fly backwards and hover upside-down.
There's a whole board dedicated to it on RC Universe.
http://www.rcuniverse.com/forum/forumid_375/tt.htm
Here's an example of a motor with the gear.
http://www.hobby-lobby.com/evp.htm
Of course hovering is very difficult and requires the plane to be percisely balenced to pull it off as there's no air going over the control surfaces.
I'm guessing this is probably a large scale electric using a modified heli gear as well. Technically it is possible with glow but nobody has developed one yet as far as I know.