Which system is responsible for maintaining balance against the main rotor's torque?

The tail rotor system is essential for maintaining balance against the main rotor's torque in a helicopter. When the main rotor spins, it creates a torque that tends to rotate the helicopter's fuselage in the opposite direction. The tail rotor system counteracts this torque by generating thrust in the opposite direction of the rotation caused by the main rotor. This thrust allows the helicopter to maintain its desired heading and stability in flight.

The tail rotor operates by creating a differential in the rotor blade pitch, adjusting the thrust it generates based on the torque produced by the main rotor. This interaction is critical for achieving controlled flight; without the tail rotor, the helicopter would spin uncontrollably due to the torque effect. The design and functioning of the tail rotor system therefore play a foundational role in helicopter aerodynamics and stability.