As said above Newtons second law. If they dont understand that what I do with students is get them to stand in front of me with legs together, then I give them a little push they go back but it is plain to see that I do to at the same speed ie equal and opposite.
The same is happening with helo,the engine is pushing rotors around and reaction is for airframe to turn opposite way. We normally fix this using a tail rotor which in essence works the same as main rotor providing lift only we turn on the side to oppose rotation, also giving us yaw control.
Last edited by crispy69; 12th November 2006 at 00:02.