The helicopters from Real Flight are totally different scriptet from what you fly until yet in SL. They use the havok physical engine from Second Life in a other way, let work gravitaion and forces (you control collective, cyclic, and yaw) at the same points and same power then in rl, to give you a real simulator feeling. You have to fly this machines active all the time. Crosswinds- and turbulences-simulation make this helicopters living... and you maybee airsick! A very smooth and realistic keyboard steering script gives you full view in mouselook while flying your helicopter.
See Real Flight on Youtube: http://www.youtube.com/user/RealFlightInc