A system for varying a wing camber, comprising: a leading edge device for a wing of an aircraft, the leading edge device configured to be actuated in an upward direction and a downward direction relative to a retracted position of the leading edge device; said system being characterised in that it further comprises: a flight control computer configured to compute a setting based on aircraft state data; a control system communicatively coupled to the flight control computer and including a control device operable to select a cruise position from a plurality of control device positions; the control system configured to automatically command the leading edge device to the setting if the cruise position is selected; and an actuation system configured to actuate the leading edge device in deflection increments of less than approximately one degree, wherein: the setting corresponds to movement of the leading edge device limited to within a deflection angle of less than approximately three degrees in the upward direction and/or a downward direction relative to the retracted position if the control device is in the cruise position; and the control system is configured to automatically command the actuation system to periodically reposition the leading edge device according to a slat positioning schedule while the control device is in the cruise position. a leading edge device for a wing of an aircraft, the leading edge device configured to be actuated in an upward direction and a downward direction relative to a retracted position of the leading edge device; said system being characterised in that it further comprises: a flight control computer configured to compute a setting based on aircraft state data; a control system communicatively coupled to the flight control computer and including a control device operable to select a cruise position from a plurality of control device positions; the control system configured to automatically command the leading edge device to the setting if the cruise position is selected; and a flight control computer configured to compute a setting based on aircraft state data; a control system communicatively coupled to the flight control computer and including a control device operable to select a cruise position from a plurality of control device positions; the control system configured to automatically command the leading edge device to the setting if the cruise position is selected; and wherein: the setting corresponds to movement of the leading edge device limited to within a deflection angle of less than approximately three degrees in the upward direction and/or a downward direction relative to the retracted position if the control device is in the cruise position; and the control system is configured to automatically command the actuation system to periodically reposition the leading edge device according to a slat positioning schedule while the control device is in the cruise position. the setting corresponds to movement of the leading edge device limited to within a deflection angle of less than approximately three degrees in the upward direction and/or a downward direction relative to the retracted position if the control device is in the cruise position; and the control system is configured to automatically command the actuation system to periodically reposition the leading edge device according to a slat positioning schedule while the control device is in the cruise position.