Patent ID: 9623965
Date: 2017-04-18
CPC Classifications: B64C

Claim:
1. A rotorcraft having an airframe extending longitudinally from a nose to a rear zone, the rotorcraft comprising at least one main lift rotor and at least one tail rotor for controlling yaw movement and arranged in the rear zone, the rotorcraft including at least one stabilizer device arranged in the rear zone, each stabilizer device being selected from a list comprising a tail plane for stabilizing the rotorcraft in pitching and a tail fin for stabilizing the rotorcraft in yaw, at least one of the stabilizer devices being a variable wing area stabilizer device , each variable wing area stabilizer device comprising an airfoil member having a stationary airfoil surface that is stationary relative to the airframe, the airfoil member having a movable airfoil surface that is movable relative to the stationary airfoil surface, wherein the movable airfoil surface is movable at least in translation relative to the stationary airfoil surface, the rotorcraft comprising: a mover system for moving the movable airfoil surface at least in translation relative to the stationary airfoil surface from a retracted position in which a reference chord of the airfoil member is at a minimum, to an extended position in which the reference chord of the airfoil member is at a maximum; and a control system connected to the mover system to position the movable airfoil surface in the retracted position when the rotorcraft has a forward speed less than a first speed threshold, and in an extended position when the rotorcraft has a forward speed greater than a second speed threshold greater than the first speed threshold.