Primary flight controls

1. 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.

2. The primary flight controls according to claim 1 , wherein the electro-mechanical interface comprises a smart interface actuator preferably composed of smart interface actuator control electronics and said at least one electro motor.

3. The primary flight controls according to claim 2 , wherein the smart interface actuator control electronics comprises smart interface actuator control means with preferably monitoring means and smart interface actuator electronics means with preferably power means.

4. The primary flight controls according to claim 3 , wherein the smart interface actuator control electronics and the electro-motors are redundant internally.

5. The primary flight controls according to claim 4 , wherein the electro-motors are physically dissimilar.

6. The primary flight controls according to claim 3 , wherein there is a one way data transfer from the smart interface actuator electronics means to the at least one electro motor except for the data related to the angular position of said at least one electro motor and the data related to the power consumption of said at least one electro motor.

7. The primary flight controls according to claim 3 , wherein the smart interface actuator control means exchanges data with said at least one flight control computer.

8. The primary flight controls according to claim 1 , wherein the at least one electro motor is of the brushless type.

9. The primary flight controls according to claim 1 , wherein at least one sensor is provided to measure the electrical current of the respective associated electro motor for analysis of the power consumption of the respective associated electro motor by the flight control computer in real time at a dashboard.

10. The primary flight controls according to claim 1 , wherein the position of said at least one electro motor is transmitted to said at least one flight control computer as position of the hydraulic servo actuator.

11. The primary flight controls according to claim 2 , wherein there is provided a multiplicity of power supply buses to supply power to the smart interface actuator, said power supply buses being connected to the helicopter's electric grid.

12. The primary flight controls according to claim 2 , wherein there is provided a multiplicity of interfaces and monitoring buses to connect the smart interface actuator to the flight control computer.

13. The primary flight controls according to claim 3 , wherein the smart interface actuator control means are provided with a multitude of sensors from said power supply buses, smart interface actuator electronics means and said electro motor.

14. The primary flight controls according to claim 1 , wherein the at least one electro motor is a direct drive torque motor with at least one clutch between the at least one electric motor and the mechanical linkage.

15. The primary flight controls according to claim 1 , wherein the at least one electro motor is a direct drive linear motor or a direct drive rotary motor.

16. The primary flight controls according to claim 1 , wherein a redundant electro motor is provided with redundant mechanical linkage arrangement.

17. A method of operating the primary flight controls of a helicopter comprising the steps of:

inputting a command by means of a control stick,

transforming said command to electric signals,

transferring said signals by a flight control computer to set-point values for main and/or tail rotor controls,

transforming an electrical command of a set-point value in at least one electric motor to a mechanical input command at a control valve of a hydraulic servo actuator, and

controlling the parameters of the at least one electric motor by smart interface actuator control electronics.

18. The method according to claim 17 , comprising the step of using a mechanical linkage of push/pull rods and/or bellcranks to transmit mechanically a command motion from an output of the at least one electric motor to a separated control valve input of the hydraulic servo actuator.

19. The method according to claim 17 , comprising the step of evaluating electrical current of the at least one electric motor in real time.

20. The method according to claim 17 , comprising the step of evaluating displacement of the at least one electric motor in real time.