Patent ID: 8113460

Claim:
A hybrid helicopter having a long range and a high forward speed, the helicopter comprising: an airframe made up of: a fuselage; a lift-producing surface secured to the fuselage; and stabilizing and maneuvering surfaces, namely for pitch: a horizontal stabilizer with at least one pitch control surface that is movable relative to the front portion; and for steering: at least one suitable stabilizer; and an integrated drive system constituted by: a mechanical interconnection system between firstly a rotor of radius (R) with collective pitch and cyclic pitch control of the blades of said rotor, and secondly at least one propeller with collective pitch control of the blades of said propeller; and at least one turbine engine driving the mechanical interconnection system; wherein said rotor is continuously driven in rotation by said at least one turbine engine regardless of the stage of flight in a normal configuration of said hybrid helicopter such that the rotational speed of the rotor varies in relation to the rotational speed of the at least one turbine, and the speed of rotation (Ω) of the rotor is equal to a first speed of rotation (Ω 1 ) up to a first flightpath air speed (V 1 ) of said hybrid helicopter, and is then reduced progressively in application of a linear relationship as a function of the flightpath air speed of said hybrid helicopter.