the problem that they hav is that thre is nothing to counter the torque of th main rotor. There are three ways this is done. 1. Have a tail rotor at a perpendiculr angle to the main rotor. Most helicopters use this method2. Have two main rotors the Marine Chinook helicopter is a main exampl of this. 3.Have counter rotating rotors. This is two rotors one above the other spinning in opposite directions. this method is used by a Russian Navy helicopter the helix. Without a counterto the torque the helicopter goes into autorotation and and a crash. If the rotor is unpowered it will not require the counter to the torque. This is in the Autogiros of the 1930's and Gyrocopters. You will then need a different form of propulsion. A strong force pulling forward and the rotors go on their own. These kind need a runway to take off and land. I am showing an exampl of a autogiro.

The wit of a misplaced ex-patriot.
I cheated on my metaphysics exam by looking into the soul of the person next to me.