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In forward flight the tip path plane is tilted forward and the Pilot's forward cyclic input will a give a minimum blade pitch angle...

  • A

    Over the nose.

  • B

    Over the retreating side.

  • C

    Over the advancing side.

  • D

    Over the tailboom.

The principle control for altering the attitude of the rotor disc (or tip path plane) and, thus, the attitude of the fuselage, is the Cyclic Control.

Movement about the longitudinal and lateral axes is performed with the cyclic control, which only changes the pitch of one blade at a time, to raise the rotor disk (or, rather, the tip path plane) at one point and tilt it in the direction you want to go. In other words, it changes the direction of the total rotor thrust, and not its magnitude, except in the one place required to lift the blade.

When a cyclic control input has been made, the rotor blade pitch will be increasing for one half of a revolution and decreasing for the next half (once per cycle, hence the name cyclic pitch).

The Phase Lag describes what happens when a control input into a rotor takes effect 90º later in the direction of rotation from the point of input.

As a result of the Phase Lag, maximum pitch will be obtained on the retreating side and minimum on the advancing side in forward flight.

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