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An ideal flight simulator replicates the 3D or spatial feel of flying while closely matching the real-world reactions of the pilot’s controls. So when pilots in the simulator activate the controls, they should experience the same response as when they are in the actual planes. Until recently, simulators relied on electrohydraulic actuators to provide feedback to pilots and power the simulator’s motion. Today, full-flight-simulator designers use the same mechanical concepts but the actuators are all-electric.

Electric actuators and components for simulators such as the Moog ball screw — which translates rotational motion into linear motion — are designed for longer life with less maintenance, and greater efficiency to provide the high levels of system availability the market requires.

Flight simulators


A key safety provision for flight simulators is preventing the cockpit/crew stations from dropping uncontrolled when there’s a loss of electric power or other fault conditions. Instead, the simulator should stop or gracefully return to its starting position to let the aircrew safely exit.

Moog’s six-degree-of-freedom simulators

One option used to ensure the pilot or aircrew escapes the simulator in case of a fault is to equip the simulator with a backup battery capable of energizing the motor long enough to get the simulator to the home position. The return-to-home feature independently drives the actuator motor using batteries and a sensorless controller when servo power is unavailable. Simulators with a backup battery closely perform as the hydraulics did with an accumulator at each leg and an abort valve, which supplied pressure to the retract side of the cylinder and returned the simulator to its start position.

Moog's Electric Rotary Control Loaders

Hydraulics can typically handle a wide range of large loads with the same servovalve and actuator, while electric actuators have a more limited range. The challenge to engineers was replicating hydraulics’ payload-handling abilities with electrics. Developments in higher-power density devices have allowed engineers to use servodrive technology to match the performance of hydraulics. For example, engineers boosted the power density of brushless servomotors by using high-energy magnets. The advantage of these upgraded components is they draw less power than hydraulic alternatives while sacrificing none of the precision, speed, and availability.

Simulator operators also require high fidelity, or smooth motions with little noise to prevent. To meet these requirements, Moog upgraded ball-screw and servodrive technology, as well as software algorithms to minimize actuator noise.

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