The tail rotor is mounted on the right side of the tail pylon and cant upward by how many degrees?

• A. 10 degrees
• B. 15 degrees
• C. 20 degrees
• D. 25 degrees

Answer: (C)

Understanding how tail rotor thrust is oriented and why it’s tilted helps you see why a 20-degree upward cant is chosen. The tail rotor’s job is to counter the main rotor’s torque and provide yaw control. If the tail rotor thrust were purely horizontal, you’d have to drive more power into anti-torque to achieve the same yaw moment, especially in hover and low-speed flight where the rotor downwash and fuselage wake affect efficiency.

Tilting the tail rotor upward by 20 degrees adds a small vertical component to the thrust. That vertical component helps offset some of the tail’s downward load and reduces the power required from the engine to achieve the same anti-torque effect, improving overall efficiency and controllability in hover and low-speed flight. It also helps the tail rotor stay effective across different flight attitudes and reduces blade loading and vibration by aligning the thrust more favorably with the tail’s aerodynamics.

So the 20-degree upward cant is a design choice that optimizes anti-torque efficiency and yaw control across the helicopter’s typical flight envelope.