How is it possible for an RC helicopter to fly upside down?

Question

I have seen a few models now that can fly upside down for sustained periods without losing altitude. How is that possible? Do the blades change position or something? It seems to me that if you turn a chopper upside down it should power straight into the ground.

Answer 1

Yes, the blades on the main rotor simply rotate so that they are opposite to their normal postions; so obviously, the lift would be on the other side of the main rotor...so flying upside-down would become possible~

Answer 2

Tha attitude i.e the angle of the rotors change, though they dont fly well upside down