Describe the role of hydraulic actuators in the UH-60 flight control system and how pilot inputs are amplified to rotor movement.

• A. Hydraulic actuators power the main rotor blades directly.
• B. Hydraulic actuators move the tail rotor to adjust yaw only.
• C. Hydraulic actuators move the swashplate and blades based on cyclic and collective input.
• D. Hydraulic actuators serve only the landing gear and braking systems.

Answer: (D)

The hydraulic actuators in the UH-60 are the force that actually moves blade pitch, not the thing that spins the rotor by themselves. Pilot inputs from the cyclic and collective are converted into hydraulic pressure through control valves and servo mechanisms, and that pressure drives actuators that move the swashplate. The swashplate translates those inputs into the pitch changes of each rotor blade as it rotates.

When you tilt the cyclic, the swashplate tilts so the blades adjust pitch differently as they move around the circle, creating the desired tilt and direction of the rotor disk. When you raise or lower collective, the actuators move the swashplate to change the pitch of all blades collectively, increasing or decreasing lift. The result is amplified, coordinated rotor movement and control of the helicopter’s attitude and flight path, all achieved through hydraulic actuation of the swashplate and blade pitch rather than direct power to the rotor blades themselves.