Operation of the Nr HI system greatly ______ tail rotor authority.

Operation of the Nr HI system greatly ______ tail rotor authority.

• A. Decreases
• B. UnDetermined
• C. No effect
• D. Increases

Answer: (D)

Raising Nr to the high-speed setting increases the available main rotor torque and engine power margin, which directly boosts the tail rotor’s anti-torque capability. In other words, with Nr HI the system allows more power to be allocated to countering main rotor torque, so pedal input produces a larger yaw response. This makes tail rotor authority greater than at normal Nr, improving yaw control in demanding situations.

Raising Nr to the high-speed setting increases the available main rotor torque and engine power margin, which directly boosts the tail rotor’s anti-torque capability. In other words, with Nr HI the system allows more power to be allocated to countering main rotor torque, so pedal input produces a larger yaw response. This makes tail rotor authority greater than at normal Nr, improving yaw control in demanding situations.