What electromechanical actuation changes for aircraft design

By eliminating hydraulic pumps, reservoirs and fluid distribution systems, engineers gain new flexibility when optimizing aircraft layouts and integrating emerging electric architectures.

Electromechanical actuation uses a controller and electric motor to convert electrical commands into the mechanical movement needed at a control surface, freeing up space and weight for other aircraft systems, cargo or passengers.

That’s also why we approach electromechanical actuation at the aircraft level. Flight control computers, control laws and actuators all influence how the aircraft ultimately responds to a pilot command.

Assure electromechanical actuators translate commands into precise mechanical movement. Making that process reliable enough for flight critical control is where the engineering challenge lies.

Actuators must reach the commanded position within the aircraft’s available space, weight and electrical power, which highlights the need for greater power density in smaller packages, particularly as manufacturers explore thinner wings and other configurations with less room for actuation hardware.

Commercial aviation and defense has decades of confidence built around hydraulics. Rajarshi Guin, senior product manager of actuation systems and motion control at Honeywell Aerospace, sees current aircraft programs as important steps in building that same pedigree for electromechanical flight controls.

“These are like the baby steps that we are taking on Archer and Electra platforms, but these are just the beginnings,” Guin says. “We put our foot forward, prove the technology, certify it.”

From there, Guin sees a progression into business aviation and eventually larger air transport platforms.

Guin gives one example of what that feedback can provide. If the flight control system commands an actuator to move 15 degrees, a position sensor can determine whether it actually moved 15 degrees. If it instead moves ten or 20 degrees, that feedback can be sent to the flight control computer so the system can identify the discrepancy and make a correction.

Other sensors can monitor conditions within the system. Temperature sensors can detect higher-than-expected heat in an electronic controller, providing another indication that something may need attention.

That feedback can also help inform maintenance. Guin says predictive health monitoring can estimate an actuator’s remaining useful life, giving operators more information about when an actuator may need to be repaired, overhauled or replaced rather than waiting for a failure.

The actuator still sits within a much aircraft control system. Guin describes the complete chain as going from “stick to surface.” A pilot input from the side stick moves through the flight control computer to the actuator controller and electric motor before producing the commanded movement at the aircraft surface.

That end-to-end approach also changes how engineering teams work together.

“Our engineers on the side stick product interact on a regular basis with the flight controls team, and the flight controls team interacts with the actuation team,” Guin says. “When it comes to integration, it’s much easier to seamlessly integrate it all together, test it on the aircraft and finally certify it.”

With the Electra EL9, we’re putting that approach into practice by working across both flight controls and actuation from the earliest stages of development.

The technology behind Assure has been decades in the making.

Brian Berry, general manager of actuation systems at Honeywell Aerospace, traces our electromechanical motion-control experience back to the 1990s. When Honeywell Aerospace divested its hydraulic flight control actuation business, the company retained its electromechanical capabilities and continued developing the technology for defense applications.

That work eventually led back to aircraft flight controls, bringing electromechanical experience with it.

Commercial and defense adoption may follow different paths. Guin sees advanced air mobility (AAM) and general aviation building the pedigree needed to move electromechanical flight controls into larger aircraft classes. Next-generation single-aisle aircraft could represent an important milestone, too.

“That would be the real test when we are going to say that, yes, electromechanical technology has finally arrived,” Guin says.

Defense presents different opportunities. Rather than expecting established fighter or bomber architectures to change immediately, Guin sees more near-term potential in logistics and dual-use platforms.

For OEMs, the decision starts with the aircraft. Available electrical power, installation space, flight control integration and certification requirements all influence where electromechanical actuation makes sense.

Our approach starts there too, looking at electromechanical actuation as part of the aircraft rather than just a component within it. The earlier those decisions enter the design process, the more opportunity engineers have to rethink what the aircraft needs around the actuator and what it may no longer need at all.