Aircraft

1. An aircraft comprising:

an aerofoil rigidly mounted to the aircraft;

a propeller mounted to the aerofoil and coupled to a propeller cyclic actuator configured to cyclically alter the pitch of the propeller as the propeller rotates; wherein

the aircraft is configured such that provision of cyclic pitch to the propeller pivots and twists at least a portion of the aerofoil about a span of the aerofoil relative to the remainder of the aircraft and an aircraft flight path vector, to thereby adjust the local angle of incidence of at least part of the aerofoil to effect roll control of the aircraft.

2. The aircraft according to claim 1 , wherein the aerofoil is mounted to the aircraft by a bearing arrangement, and the aircraft is configured such that provision of cyclic pitch pivots the aerofoil about the bearing between a first position in which a leading edge of the aerofoil faces generally forwardly, and a second position in which the leading edge of the aerofoil faces generally upwardly.

3. The aircraft according to claim 1 , wherein the aerofoil comprises one or more of a wing, a vertical tail surface and a horizontal tail surface.

4. The aircraft according to claim 3 , wherein the aircraft comprises a propeller mounted to a port wing, and a further propeller mounted to a starboard wing.

5. The aircraft according to claim 4 , wherein the aircraft comprises a plurality of propellers mounted to each wing.

6. The aircraft according to claim 1 , wherein the respective propeller cyclic actuator comprised a motor configured to pivot a respective propeller blade about a longitudinal axis of the respective blade.

7. The aircraft according to claim 1 , wherein each propeller cyclic actuator comprises a swash plate arrangement.

8. The aircraft according to claim 3 , wherein the wing comprises an aspect ratio greater than 10.

9. The aircraft according to claim 3 , wherein each propeller is electrically driven, and each propeller is located upstream of the respective wing leading edge.

10. The aircraft according to claim 1 , wherein the aircraft comprises one or more generator arrangements configured to provide electrical power to one or more propellers, and wherein the generator arrangement comprises one or more internal combustion engine located outboard of the centre of thrust of the propellers on the respective wing.

11. The aircraft according to claim 1 , wherein the aircraft comprises a health monitoring system to determine whether one or more cyclic actuators is operable, and an aircraft control system configured to decelerate the aircraft to a speed below a critical flutter speed where one or more cyclic actuators is found to be inoperable.

12. The aircraft according to claim 1 , further comprising a controller that effects the roll control by altering the pitch of the propeller, via the propeller cyclic actuator, as the propeller rotates to twist at least the portion of the aerofoil about the span of the aerofoil and adjust the local angle of incidence of at least the part of the aerofoil.

13. The aircraft according to claim 1 , wherein the controller alters the pitch of the propeller to a different extent to that of another propeller of the aircraft to twist at least the portion of the aerofoil about the span of the aerofoil and adjust the local angle of incidence of at least the part of the aerofoil effect a roll moment of the aircraft.

14. The aircraft according to claim 1 , wherein the local angle of incidence of at least part of the aerofoil to effect roll control of the aircraft is adjusted by deformation of the aerofoil.

15. A method of controlling an aircraft, the aircraft comprising a starboard wing and a port wing each rigidly mounted to the aircraft, at least one propeller mounted to the port wing and at least one propeller mounted to the starboard wing, each propeller being coupled to a propeller cyclic actuator configured to cyclically alter a pitch of the propeller as the propeller rotates, the aircraft being configured such that provision of the cyclic pitch to the propeller pivots at least a portion of the respective wing about a span of the wing relative to the remainder of the aircraft and an aircraft flight path vector, to thereby adjust the local angle of incidence of at least part of the wing, the method comprising:

altering the propeller cyclic on the propeller to one of the port and starboard wing to a different extent to that of the propeller mounted to the other of the port and starboard wing to twist at least a portion of the respective wing to thereby adjust the angle of incidence of the respective wing to effect a roll moment of the aircraft.

16. The method according to claim 15 , wherein each wing of the port and starboard wings comprises a plurality of propellers, and the method comprises providing propeller cyclic pitch on at least one of the propellers mounted to the wing to a different extent to that of one of the other propellers mounted to the wing to thereby effect a local twisting of a portion of the wing to effect a local reduction or increase of angle of attack of that wing to effect roll control.

17. The method according to claim 15 , wherein the aircraft comprises at least one propeller on each wing of the port and starboard wings, and the method comprises providing cyclic pitch of all of the propellers in unison to twist the port and starboard wings relative to the flight path vector to effect an increase in angle of incidence of both wings.

18. The method according to claim 15 , wherein the method comprises detecting or predicting a vibration of the wing, and using cyclic propeller pitch to effect local twisting of a portion of the wing to dampen the detected vibration.

19. The method according to claim 15 , wherein the method comprises detecting or predicting a gust, and using cyclic propeller pitch to effect twisting of at least a portion of the wing to reduce or increase or reduce the angle of incidence of the respective portion of the wing to accommodate the change in lift produced by the gust.

20. The method according to claim 15 , wherein the local angle of incidence of at least part of the wing to effect roll control of the aircraft is adjusted by deformation of the wing.

21. An aircraft comprising:

a propeller mounted to an aerofoil and coupled to a propeller cyclic actuator configured to cyclically alter the pitch of the propeller as the propeller rotates; wherein

the aircraft is configured such that provision of cyclic pitch to the propeller pivots at least a portion of the aerofoil about a span of the aerofoil relative to the remainder of the aircraft and an aircraft flight path vector, to thereby adjust the local angle of incidence of at least part of the aerofoil, and

the aircraft comprises a health monitoring system to determine whether one or more cyclic actuators is operable, and an aircraft control system configured to decelerate the aircraft to a speed below a critical flutter speed where one or more cyclic actuators is found to be inoperable.