What Are the Different Types of Actuators Used in Aerospace and Defense Settings?

Dependably piloting a fighter jet, launching a spacecraft, operating a missile defense system, or using any such advanced platforms relies on a wide array of components that operate with unwavering consistency. Among those are actuators, which serve to convert electrical, hydraulic, or pneumatic energy into mechanical motion, enabling the movements that control flight surfaces, deploy weapons, position antennas, and so much more.

Given the many functions actuators perform, aerospace and defense platforms rely on an equally diverse range of actuator types for specific environments, power requirements, and operational demands. Read on as we explore the design and uses of some actuator types that are commonly found across military aircraft, space vessels, and defense systems.

Hydraulic Actuators

Hydraulic actuators use incompressible pressurized fluid to generate mechanical motion. This is achieved by channeling pressurized fluid into a sealed cylinder, where the resulting pressure differential forces a piston to move within the housing.

Advantages and Uses

These actuators are renowned for their ability to deliver extremely high force outputs with consistent precision. Additionally, they have rapid response times and the ability to sustain high loads without mechanical drift, with their robust construction further bolstering their ability to perform under extreme temperatures and pressures. As such, hydraulic actuators are indispensable for:

Primary and secondary flight control surfaces
Landing gear extension and retraction mechanisms
Arresting hooks and catapult systems on carrier-based fighter jets
Thrust vectoring in advanced combat aircraft

Pneumatic Actuators

Pneumatic actuators utilize compressed air to drive pistons or diaphragms within a cylinder. Similar in form to hydraulic systems, pneumatic actuators trade high force capability for lighter weight and faster motion, being favored in designs where speed and simplicity are more essential than load-bearing capacity.

Advantages and Uses

Because they operate with lower force and are more sensitive to pressure variations, pneumatic actuators are less common in core flight systems, instead proving their value in auxiliary roles. Their fast actuation speed and relatively simple construction make them cost-effective for light-to-medium-duty tasks like:

Aircraft door mechanisms and cargo bay operations
Environmental control systems (ECS) that regulate airflow and pressure
Braking and control systems in ground support vehicles
Countermeasure dispensers in defense aircraft and armored vehicles

Electric Actuators

Electric actuators convert electrical energy into motion, accomplishing this through components like ball screws, gear trains, or linear actuators that translate a motor's rotational movement into precise linear or rotary output. To optimize performance, electric actuators are often equipped with integrated control electronics that precisely regulate speed, torque, and positioning.

These actuators come in many different types to offer distinct functional advantages. For instance, brushless DC motors are a widely used variant that result in smooth, continuous motion for dynamic systems requiring sustained or variable movement. Stepper motors are another popular option, operating by moving in discrete steps that allow for accurate positioning without the need for feedback systems in simpler configurations.

Advantages and Uses

Electric actuators are lightweight, energy-efficient, and operate without the risk of leaks as is the case with some actuator types. Their self-contained build and reduced infrastructure requirements simplify integration, making them ideal for systems that prioritize reduced weight. As a result, electric actuators are usually applied in:

Flap and slat deployment systems in modern fighter aircraft
Missile fin and canard control surfaces
Satellite antenna positioning and payload bay operations
UAV flight control and servo systems

Electro-Hydraulic Actuators (EHAs)

Electro-hydraulic actuators integrate an electric motor-driven hydraulic pump with a compact actuator assembly, forming a self-contained unit that eliminates the need for centralized hydraulic systems. This combination delivers the high force capabilities of hydraulics alongside the precise control and responsiveness of electric systems.

Advantages and Uses

In addition to the benefits that we just touched on, EHAs are increasingly employed in advanced aerospace platforms due to their reduced weight, modular nature, and sealed design. They tend to be found in:

Stealth aircraft and fifth-generation fighters that prioritize distributed actuation
Missile and ordnance guidance fins
High-torque mechanisms in satellite orientation systems
Rotor blade pitch control in advanced helicopters

Piezoelectric Actuators

Piezoelectric actuators are solid-state devices with no moving mechanical parts, using piezoelectric materials that deform and produce precise mechanical displacement when voltage is applied. Despite the small range of motion they provide, response time is nearly instantaneous and resolutions can reach the sub-nanometer scale.

Advantages and Uses

This type is prized for its unmatched precision, speed, and ability to perform in environments with strict spatial or power constraints. Furthermore, piezoelectric actuators offer low thermal expansion and resistance to radiation, as well as minimal wear and vibration due to their lack of moving features, making them well-suited for:

Satellite instrument alignment and calibration
Beam steering systems in laser-guided weaponry
Optical lens adjustments for high-resolution imaging in reconnaissance satellites
Navigation system stabilization in inertial guidance platforms

ASAP Purchasing: Your Source for Dependable Actuators

For procurement specialists and maintenance teams operating in demanding fields, having access to a dependable source of high-quality actuators and other such components is vital. ASAP Semiconductor, through its comprehensive platform ASAP Purchasing, offers a robust selection of aviation, aerospace, and defense components that are thoroughly vetted for quality, traceability, and compliance–including many types of actuators.

By offering a vast inventory and competitive fulfillment solutions with fast lead times, ASAP Purchasing enables professionals to meet operational requirements efficiently on one platform. In a field where components can make the difference between mission success or failure, partnering with a trusted distribution platform makes all the difference. We look forward to serving you, so be sure to explore our website and get in touch with our experts.