Control system for rotorcraft for preventing the vortex ring state
AssigneeBell Helicopter Textron Inc.
InventorRonald L. Kisor
Life of this patent
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Abstract
A flight control system for a rotorcraft to prevent the adverse effects of the vortex ring state is disclosed. In the flight control system of the present invention, selected control inputs are sent the rotorcraft prior to the onset of the vortex ring state. In the preferred embodiment, the control inputs are transient, do not require input from the pilot, and do not affect the flight path of the rotorcraft.
Claims12
A method of preventing a rotorcraft having a rotor disk from entering a sustained vortex ring state comprising the steps of:
- defining a selected flight regime which indicates that the sustained vortex ring state is an imminent possibility for the rotorcraft, the selected flight regime consisting of a selected forward airspeed and a selected rate of descent of the rotorcraft;
- and
- continually perturbing the rotor disk while the rotorcraft is in the selected flight regime.
A method of preventing a rotorcraft having at least two rotor disks from entering a sustained vortex ring state comprising the steps of:
- defining a selected flight regime indicative of a predetermined probability that the rotorcraft will enter the sustained vortex ring state, the selected flight regime consisting of a selected forward airspeed and a selected rate of descent of the rotorcraft;
- detecting whether the rotorcraft has entered the selected flight regime;
- and
- continually perturbing the rotor disks with oscillatory cyclic inputs if the rotorcraft enters the selected flight regime.
Dependencies are inferred from the claim text.