Mac H. - True about torque during auto. (Auto rotation is usually the Emergency Procedure for loss of Tail Rotor thrust). But the Tail Rotor IS the main yaw control and would assist in choosing where to best land in a power off auto rotation. I hope by now, aviation has learned that LiFe batteries are safe enough (and lightweight) to be used as alternate electric power in the case of engine failure or alternator/generator failure.
Just observing the meteorological conditions, I’m wondering about Bell’s considerations for Tail Rotor icing. I DO like the thought of the requirement for only 3 of 4 rotors needed for full functionality.