Tailrotors

Tailrotors are the vertical-axis rotors mounted at the end of a helicopter’s tail boom. Their primary function is to counteract the torque produced by the main rotor, allowing the aircraft to maintain heading and to yaw left or right in response to pedal input. The tail rotor creates thrust by varying the pitch of its blades, and is typically driven by a shaft connected to the main rotor gearbox. Most single-main-rotor helicopters use a two- or three- or four-blade tail rotor, with the exact count varying by model and design.

In normal operation, pilot pedals adjust the tail rotor’s thrust to produce the desired yaw moment. Modern helicopters may include yaw dampers, stability augmentation, and autopilot features to assist heading control. While tail rotors are common, several alternative anti-torque configurations exist. A fenestron, an enclosed tail-rotor unit, is integrated into the tail fin and reduces noise and some safety risks. NOTAR systems use directed air rather than a conventional tail rotor to provide anti-torque. Other designs, such as tandem-rotor or coaxial-rotor configurations, eliminate the tail rotor entirely (for example, CH-47 Chinook and some Kamov/other designs), relying on multiple main rotors to balance torque.

Tailrotor safety and maintenance are important, as the rotor operates at high speed and is exposed to ground debris. Common concerns include tail-rotor strikes during ground operations or in confined spaces, vibration, and wear on the tail rotor blades and gearbox. Regular inspection and protection features help mitigate these risks.