If the tail rotor loses thrust or fails, which flight characteristic is most immediately affected?

If the tail rotor loses thrust or fails, which flight characteristic is most immediately affected?

• A. Yaw remains stable due to auto-balancing system.
• B. The helicopter will experience a slight nose-down pitch moment.
• C. The main rotor rpm will automatically increase to compensate.
• D. Uncontrolled yaw and loss of directional control.

Answer: (D)

The main idea is that the tail rotor provides anti-torque to counter the torque produced by the main rotor. When tail rotor thrust is lost, there’s nothing to oppose that torque, so the fuselage yaws uncontrollably and the helicopter loses directional control almost immediately. This yaw happens quickly because the opposing force that keeps the nose pointed and the helicopter aligned with the intended direction is gone, so the aircraft swivels in the direction of the unopposed main-rotor torque. There isn’t an automatic system that compensates for tail-rotor failure, no automatic increase in main-rotor rpm to fix the balance, and no immediate nose-down pitch moment caused by the loss itself. The defining consequence is uncontrolled yaw and loss of directional control.

The main idea is that the tail rotor provides anti-torque to counter the torque produced by the main rotor. When tail rotor thrust is lost, there’s nothing to oppose that torque, so the fuselage yaws uncontrollably and the helicopter loses directional control almost immediately. This yaw happens quickly because the opposing force that keeps the nose pointed and the helicopter aligned with the intended direction is gone, so the aircraft swivels in the direction of the unopposed main-rotor torque. There isn’t an automatic system that compensates for tail-rotor failure, no automatic increase in main-rotor rpm to fix the balance, and no immediate nose-down pitch moment caused by the loss itself. The defining consequence is uncontrolled yaw and loss of directional control.