System for controlling a flight control surface

1. A system for controlling a flight control surface, wherein said system comprises:

a first electromagnetic actuator (EMA) and a second EMA, each of which are connected to said flight control surface;

and wherein each EMA is configured to be arranged in, and switched between, three modes;

said three modes comprising:

an active mode, a stand-by mode and a blocked, or anti-extension, mode

wherein:

said first EMA comprises a first Motor Drive Electronics (MDE) and a first solenoid; and

said second EMA comprises a second MDE and a second solenoid;

said second MDE of said second EMA is connected to said first solenoid of said first EMA;

said first MDE of said first EMA is connected to said second solenoid of said second EMA; and

in the event of failure of the first EMA, the second EMA is configured to unlock the first EMA by energizing the solenoid of the first EMA, thereby switching said system into said active/standby mode.

2. The system of claim 1 ,

wherein the system is configured to be operable in and switchable between:

an active/active mode, wherein both said first and second EMAs are in the active mode;

an active/stand-by mode, wherein the first EMA is in the active mode and the second EMA is in the stand-by mode; and

a blocked/blocked mode or anti-extension mode, wherein both EMAs are in a blocked, or anti/extension mode.

3. The system of claim 1 , wherein, in normal operation, both of the first and second EMAs are operating in said active mode.

4. The system of claim 1 , wherein said first and second EMAs are connected to the flight control surface that is being controlled.

5. The system of claim 1 , wherein the first and second EMAs are each connected to a flight control computer (FCC).

6. The system of claim 1 , said first and second EMAs are provided in a housing and wherein, in the event that a temperature of said housing reaches an upper threshold, the system is configured to operate with both the first and the second EMAs in said blocked/blocked mode.

7. The system of claim 1 , wherein, in the event that either or both the first and second EMAs fail, the system is configured to switch the first and second EMAs into said blocked/blocked mode.

8. A method for controlling a flight control surface, comprising:

providing a first electromagnetic actuator (EMA) and a second EMA;

connecting each of said first and second EMAs to said flight control surface;

wherein each EMA is configured to be arranged in, and switched between, three modes; said three modes comprising: an active mode, a stand-by mode and a blocked, or anti-extension, mode,

the method further comprising:

controlling said flight control surface by switching between and operating said EMAs in an active/active mode, wherein both said first and second EMAs are in the active mode;

an active/stand-by mode, wherein the first EMA is in the active mode and the second EMA is in the stand-by mode; and

a blocked/blocked mode or anti-extension mode, wherein both EMAs are in a blocked, or anti/extension mode; and

in the event of failure of the first EMA, operating said flight control surface by the second EMA unlocking, via the first solenoid the first EMA due to the second EMA energizing the solenoid of the first EMA, thereby switching said system into said active/standby mode.

9. The method of claim 8 , wherein said first EMA comprises a first Motor Drive Electronics (MDE) and a first solenoid; and

said second EMA comprises a second MDE and a second solenoid, and wherein

said second MDE of said second EMA is connected to said first solenoid of said first EMA;

and wherein said first MDE of said first EMA is connected to said second solenoid of said second EMA.

10. The method of claim 8 , comprising, in normal operation, controlling said flight control surface by operating both of the first and second EMAs in said active mode.

11. The method of claim 8 , wherein, said first and second EMAs are provided in a housing and wherein, in the event that a temperature of said housing reaches an upper threshold, controlling the flight surface with both the first and the second EMAs in said blocked/blocked mode.

12. The method of claim 8 , wherein, in the event that either or both the first and second EMAs fail, controlling the flight surface with the first and second EMAs being held in said blocked/blocked mode.