Cyclic Blade Control
Cyclic controls are used to change a helicopter's roll and pitch. Push rods or hydraulic actuators tilt the outer swashplate in response to the pilot's commands. The swashplate moves in the intuitively expected direction, tilting forwards to respond to a forward input, for instance. However "pitch links" on the blades transmit the pitch information way ahead of the blade's actual position, giving the blades time to "fly up" or "fly down" to reach the desired position, in addition to a 90 degrees advance to account for the gyroscopic precession. That is, to tilt the helicopter forward, the difference of lift around the blades should be maximum along the left-right plane, creating a torque that, due to the gyroscopic effect, will tilt the rotor disc forward and not sideways.
Read more about this topic: Swashplate (helicopter)
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