Woodward is a leader in the design, development and manufacture of hydraulic boost actuators, in addition to main rotor and tail rotor flight control actuators (MRA/TRA) that control helicopter swash plates. These actuators are typically located in series with the mechanical linkage between the pilot’s cockpit controls and the MRA and TRA, and provide output position proportional to pilot input position but at increased (boosted) force output.
Woodward hydraulic boost actuators contain jam-proof servo-control valves, critical to flight control systems. They can be combined with other functionality such as Stability Augmentation System (SAS) electro-hydraulic position inputs to the flight control system.
Boost actuators have relatively lower force output than MRAs and TRAs, as they are only required to overcome inherent friction and drag in the mechanical control linkage that would otherwise be felt at the pilot control input. An example of a Woodward HRT boost actuator is the Cyclic Secondary Boost Actuator for the USMC Bell AH-1Z Viper.