System and method for slowing down aircraft

1. A method for slowing down an aircraft having a propeller and propeller blades, the method comprising:

operating the propeller at a reference speed with the propeller blades in a first position;

applying a load to the propeller to slow down a rotational speed of the propeller when the propeller is in a windmilling state or just before the propeller enters the windmilling state;

adjusting the propeller blades to a second position in response to the load being applied, to increase the rotational speed of the propeller back towards the reference speed; and

operating the propeller at the reference speed with the propeller blades in the second position.

2. The method of claim 1 , wherein applying the load to the propeller comprises applying a mechanical load to a rotating shaft of the propeller.

3. The method of claim 1 , wherein applying the load to the propeller comprises applying an electrical load to extract power from the propeller.

4. The method of claim 3 , further comprising distributing the power extracted from the propeller to one or more systems in the aircraft.

5. The method of claim 3 , further comprising dissipating in heat the power extracted from the propeller.

6. The method of claim 1 , wherein applying the load to the propeller comprises using an accessory mounted to a reduction gear box of an engine coupled to the propeller.

7. The method of claim 1 , wherein adjusting the propeller blades to the second position comprises decreasing a blade angle of the propeller blades.

8. The method of claim 3 , wherein applying the load to the propeller comprises extracting power as a function of a speed of the aircraft.

9. A system for slowing down an aircraft having a propeller, the system comprising:

a processor; and

a non-transitory storage medium coupled to the processor and having stored thereon program instructions executable by the processor for:

applying a load to the propeller to slow down a rotational speed of the propeller when the propeller is in a windmilling state or just before the propeller enters the windmilling state, the propeller blades being in a first position before the load is applied;

adjusting the propeller blades to a second position in response to the load being applied, to increase the rotational speed of the propeller back towards a reference speed; and

operating the propeller at the reference speed with the propeller blades in the second position.

10. The method of claim 9 , wherein applying the load to the propeller comprises applying a mechanical load to a rotating shaft of the propeller.

11. The method of claim 9 , wherein applying the load to the propeller comprises applying an electrical load to extract power from the propeller.

12. The method of claim 11 , wherein the program instructions are further executable for distributing the power extracted from the propeller to one or more systems in the aircraft.

13. The method of claim 11 , wherein the program instructions are further executable for dissipating in heat the power extracted from the propeller.

14. The method of claim 9 , wherein applying the load to the propeller comprises using an accessory mounted to a reduction gear box of an engine coupled to the propeller.

15. The method of claim 9 , wherein adjusting the propeller blades to the second position comprises decreasing a blade angle of the propeller blades.

16. The method of claim 11 , wherein applying the load to the propeller comprises extracting power as a function of a speed of the aircraft.

17. A propeller control system comprising:

a propeller coupled to an engine, the propeller having propeller blades;

a pitch change mechanism;

a load; and

a controller configured for:

applying the load to the propeller to slow down a rotational speed of the propeller when the propeller is in a windmilling state or just before the propeller enters the windmilling state, the propeller blades being in a first position before the load is applied;

adjusting the propeller blades to a second position in response to the load being applied, to increase the rotational speed of the propeller back towards a reference speed; and

operating the propeller at the reference speed with the propeller blades in the second position.