Primary flight controls

Primary flight controls for main and/or tail rotors of helicopters with an electro-mechanical interface between any of fly-by-wire and/or of fly-by-light controls and hydraulic servo actuators said fly-by-wire and/or of fly-by-light controls commanding the position of the hydraulic servo actuators towards said main and/or tail rotor controls, comprising

• at least one control stick to be handled by the at least one pilot,
• at least one flight control computer connected to said control stick,
• at least one electro motor of said electro-mechanical interface for each of said main and/or tail rotor controls, said at least one flight control computer preparing and transferring electric signals to said at least one electro motor, and
• mechanical linkages of said electro-mechanical interface connecting the at least one electro motor to the hydraulic servo actuators of the main and/or tail rotor controls,
• wherein for each of the main and/or tail rotor controls there is provided but one of the hydraulic servo actuators, connected by one of the mechanical linkages to said at least one electro motor, said one hydraulic servo actuator being of the type having the one mechanical linkage connected to its input and its output and the at least one electro motor being directly linked to the mechanical linkage, the position of said at least one electro motor having a reference to said one mechanical linkage and the torque delivered by said at least one electro motor to the hydraulic servo actuator being related to the power consumption of said at least one electro motor.