Tail rotors may be either of the pusher or pulling variety and can be located either on the left – or right-hand side of a vertical fin. All designs suffer from interference effects between the rotor and the vertical fin.

In the pusher style the wake of the tail rotor is convected away from the vertical tail. This allows the accelerated air mass to exit the rotor system without encountering any obstruction, resulting in less thrust loss. This means that the vertical fin only distorts the inflow into the tail rotor, the consequences of which are a nonuniform inflow and higher induced power requirement.

In contrast, the pulling design has the vertical fin located inside the high-energy region from the tail rotor wake. While this “blockage” effect tends to increase the tail rotor thrust, there is also a significant force applied to the vertical tail that is in the opposite direction to the anti-torque thrust requirement. However, the net effect is a decrease in thrust compared to what would be obtained if the rotor was operating in isolation.

The advantage of a pushing tail rotor over a pulling tail rotor is less thrust loss by free outflow of the accelerated air mass.

The free outflow of accelerated air mass in a pushing tail rotor design helps to maintain smoother airflow patterns around the tail rotor system, reducing aerodynamic disturbances and enhancing control authority, especially during complex manoeuvres or high-speed flight.