Having enough co-ordination to control 5 different things using all 4 limbs at the same time! Last time I was in one: Left hand: Up/down and twist (kinda like a handbrake that you can twist too - can't remember exactly what it was for, up/down for rear rotor angle maybe, and then the twist for the angle of the main blades... so you have one hand controlling two different properties of two completely separate parts of the helicopter ) Right hand: Main 'joystick' for main rotor (360 degree movement) Right and Left feet: Counterbalancing each other for rear rudder angle (All of those are pretty sketchy 'I thinks', this was ~8 years ago...) I was allowed to control just the main stick at high speed and low speed - high speed was ok, but trying to hover is bloody impossible! Well worth trying to get some more info and a flight though, it's uber interesting Edit: Here we go! http://youtube.com/watch?v=lVlIWbJXSJk. My memory is poo it seems :$