To: NickLappos
The following is taken from the CH-47D Airframe Drive/Rotor Systems H7-U-10-1
Volume 2 (Customer Training Manual published by Boeing Helicopters) (page 6-24).
FLIGHT CONTROLS
PITCH INPUT FORWARD
When the pilot moves the cyclic stick forward the 1st stage mixing unit will extend the output control of the aft head, and retract the output control to the forward head. This extension and retraction is called differential thrust between heads or differential collective pitch. The second stage mixing unit will extend the two outputs to the aft rotor system, and retract the outputs to the forward rotor system.
There is no aft cyclic input. Forward cyclic input is made by the retraction of the electric actuators attached to the forward and aft swashplates when the helicopter reaches around 60 knots. When the helicopter slows down below 60 knots the actuators extend removing forward cyclic input. Lateral cyclic is available at all times.
TO: SASless: Thanks for the correction however the movement of the cyclic stick fore and aft does not effect the fore and aft rotors cyclically it effects them collectively. This input either raises or lowers the swashplates it does not tilt them. Due to the design of the swashplates and their connection to the electric actuator there may be a very slight cyclic input but this is not intentionally input by the pilot.
