It seems a bit odd. The main rotor imparts an opposite spin on the body. Tha tail rotor is there to counteract that spin by blowing sideways. A horizontal one would have to use just its spin, not getting the benefit of the air mass being pushed sideways.
Why not?
It seems a bit odd. The main rotor imparts an opposite spin on the body. Tha tail rotor is there to counteract that spin by blowing sideways. A horizontal one would have to use just its spin, not getting the benefit of the air mass being pushed sideways.
That only works if both rotors are the same size and speed.
Perhaps Sikorsky’s tethers to the ground worked around the problem for that photo anyway. Not sure.