Abstract: A helicopter comprising: a single main rotor for forwards motion and for support; and an anti-torque system comprising: an auxiliary, anti-torque rotor rotated from the engine means of said main rotor and exerting controllable anti-torque lateral thrust; and at least one steering airfoil that is controllable in steering and that generates anti-torque transverse lift. According to the invention, the helicopter includes automatic swivel control means for automatically controlling the swivel angle of said steering airfoil as a function of the collective pitch angle of said main rotor and of the forward speed of said helicopter.

Abstract: A directional and stabilizing device is provided including a faired antitorque rotor, driven in rotation in a transverse aperture formed in a fairing slanted with respect to the vertical by an angle between 0.degree. and 45.degree.. It also includes a "V" empennage fixed to the top of the fairing and the two aerodynamic surfaces of which extend disymmetrically with respect to the vertical plane passing through the top of this fairing, the aerodynamic surfaces being slanted in angular planes between 0.degree. and 45.degree..