A rotary wing prototype I worked on for a while and recently decided to upload. It's designed to mimic the way modern helicopters work and is thus just like real helicopters capable of flying upside down. It flies quite stable and with a little practice is easy to use.
Up/Down arrows controll ascent/decent
Left/Right arrows rolls the craft to the left and right
Z/X rotates the craft
F2 pitches forward F1 pitches backwards.
Flaps can be used to create a constant positive lift when you want to concentrate on manouvering.
Start both engines and set them to full throttle before waiting for about fifteen seconds for both rotors to spin up to full speed. Then use the up arrows to take off and the other controlls to keep the craft steady. With practice the helicopter is quite responsive and manouverable.