remember that the helicopter just hangs under the blades. so when the aircraft is turned sideways the aerodynamics is gone and the drag on the air frame holds it from moving through the air as fast as it needs, tiping the heli sidewards,lowering the disc in direction of movement, increasing sidward air speed, increasing drag on the frame, to stop the disc nosing down(in the direction of travel)too much oposite cyclic will be necisarie. and if maximum cyclic(sidewards)is achieved, mast bumping would be geting close. <img src="confused.gif" border="0">