If you had asked if there was ever a helicopter that flew like an airplane (re. Control input, Control response and control neutralization the correct answer would be the AH-46 Cheyenne or its’ predecessors. On the Cheyenne the pilots did not have direct input into the rotor control system. Instead he moved a servo and the servo applied a spring load into the control gyro. The control gyro would respond due to gyroscopic precession and it would apply the control input into the pitch change horn. Once the rotor had reached its’ assigned position the pilot would neutralize his cyclic control much in the same way a fixed wing pilot would neutralize his controls after achieving the desired attitude. The control gyro however would maintain the commanded position due to its’ rigidity in space which maintained the original input from the pilot. The gyro however was not in the same plane as the disc.
[ 05 September 2001: Message edited by: Lu Zuckerman ]