HELICOPTERE HYBRIDE RAPIDE A GRANDE DISTANCE FRANCHISSABLE ET ROTOR DE SUSTENTATION OPTIMISE

A hybrid helicopter (1) includes firstly an airframe provided with a fuselage (2) and a lift-producing surface (3), together with stabilizer surfaces (30, 35, 40), and secondly with a drive system including: a mechanical interconnection system (15) between firstly a rotor (10) of radius (R) with collective pitch and cyclic pitch control of the blades (11) of the rotor (10), and secondly at least one propeller (6) with collective pitch control of the blades of the propeller (6); and at least one turbine engine (5) driving the mechanical interconnection system (15). The speed of rotation ( ) of the rotor (10) is equal to a first speed of rotation ( 1) up to a first flightpath air speed (V1) of the hybrid helicopter (1), and is then reduced progressively in application of a linear relationship as a function of the flightpath air speed of the hybrid helicopter.