stabilators

A stabilator, or all-moving tailplane, is a type of aircraft horizontal tail that deflects as a single unit to control pitch, replacing the conventional tailplane with a separate elevator. In a stabilator, the entire tail surface rotates about a hinge line near its leading edge, so deflection changes lift on the tail and thus the aircraft’s pitch moment.

Operation and design: The stabilator is driven by hydraulic or electric actuators connected to the cockpit control system. Because the whole surface moves, it can provide a larger control moment than a fixed tailplane with a separate elevator. Some designs incorporate servo tabs, balance surfaces, or stability augmentation to adjust control feel and reduce pilot workload. Anti-stall and trim systems are often included to manage handling characteristics across the flight envelope.

Advantages: Stabilators offer greater pitch authority for a given tail area, especially at high speeds, and can simplify or reduce the size of the tail structure. They can provide more favorable aerodynamics in certain configurations and may contribute to lighter control forces and improved maneuverability.

Disadvantages: The all-moving surface can be more complex and heavier to install, with higher power and control system requirements. At low speeds or near stall, stabilators can produce pitch behavior that requires careful design and augmentation to avoid loss of control. Some configurations have a higher propensity for pitch sensitivity, requiring measures such as stick-ppusher systems or automated stability control.

Usage and variants: Stabilators have been used on a range of aircraft, including some high-performance, military, and civil designs, where the benefits of increased pitch control are desired. They remain a distinct alternative to conventional tailplanes with separate elevators.