A compound aircraft located within a reference frame constituted by a longitudinal direction X extending from the front of said aircraft towards the rear of said aircraft, an elevation direction Z extending upwards perpendicularly to said longitudinal direction X, and a transverse direction Y extending from left to right perpendicularly to said longitudinal direction X and elevation direction Z, said aircraft comprising: - a fuselage, - a main rotor located above said fuselage, provided with a plurality of blades and driven in rotation about an axis substantially parallel to said elevation direction Z and which provides said aircraft with lift as a result of the aerodynamic lift of said blades, - a main anti-torque device generating a main torque which opposes the rotor torque C R generated as a result of the rotation of said main rotor, - at least one wing (11, 11') located beneath said main rotor and extending substantially in said transverse direction Y, and - at least two flaps (12, 12') located beneath said main rotor, at least one flap (12, 12') being located on a first side of said fuselage relative to said longitudinal direction X, at least one flap (12, 12') being located on a second side of said fuselage relative to said longitudinal direction X, each flap (12, 12') extending substantially in said transverse direction Y, each flap (12, 12') being connected to said at least one wing (11, 11') and mobile with respect to said wing (11, 11'), said at least one wing (11, 11') forming with the flap or flaps (12, 12') which are connected thereto a wing (11, 11') and flap (12, 12') assembly on each side of said fuselage, said wing (11, 11') and flap (12, 12') assemblies capable of generating longitudinal aerodynamic forces (F 1, F 2) directed in said longitudinal direction X on either side of said fuselage under the effect of the airflow generated in reaction to said aerodynamic lift of said main rotor and, consequently, capable of generating a complementary torque added to said main torque in order to oppose said rotor torque C R, said wing (11, 11') and flap (12, 12') assemblies having identical aerodynamic profiles and said flaps (12, 12') being orientable asymmetrically with respect to the airflow generated as a reaction to said aerodynamic lift of said main rotor on either side of said fuselage so that said longitudinal aerodynamic coefficients C T of said aerodynamic profiles are different on either side of said fuselage, characterised in that the aircraft is configured such that, when said flaps are oriented asymmetrically, the displacement of each flap (12, 12') being defined by a deflection angle, a first deflection angle δ 1 of each flap (12, 12') which is located on said first side of said fuselage is greater than an inversion deflection angle δ i and less than a stall deflection angle δ D while a second deflection angle δ 2 of each flap (12, 12') located on said second side of said fuselage is less than said inversion deflection angle δ i, longitudinal aerodynamic coefficient C T of each wing (11, 11') and flap (12, 12') assembly being zero for a deflection angle of said flaps (12, 12') which is equal to said inversion deflection angle δ i, said stall deflection angle δ D corresponding to an aerodynamic stall of each flap (12, 12'). - a fuselage, - a main rotor located above said fuselage, provided with a plurality of blades and driven in rotation about an axis substantially parallel to said elevation direction Z and which provides said aircraft with lift as a result of the aerodynamic lift of said blades, - a main anti-torque device generating a main torque which opposes the rotor torque C R generated as a result of the rotation of said main rotor, - at least one wing (11, 11') located beneath said main rotor and extending substantially in said transverse direction Y, and - at least two flaps (12, 12') located beneath said main rotor, at least one flap (12, 12') being located on a first side of said fuselage relative to said longitudinal direction X, at least one flap (12, 12') being located on a second side of said fuselage relative to said longitudinal direction X, each flap (12, 12') extending substantially in said transverse direction Y, each flap (12, 12') being connected to said at least one wing (11, 11') and mobile with respect to said wing (11, 11'), said at least one wing (11, 11') forming with the flap or flaps (12, 12') which are connected thereto a wing (11, 11') and flap (12, 12') assembly on each side of said fuselage,