Abstract: A control system for lift-generating means, the control system comprising: detector means for detecting at least one parameter from which stall may be calculated; scaling means for determining a scale factor dependent on the or each detected parameter; and multiplier means for multiplying an incoming lift demand signal by the scale factor to provide an outgoing lift demand signal.

Abstract: A method of determining the lift generated by a lift-generating member, the lift-generating member being coupled to a component within the lift load path with the lift load path component experiencing strain as a result of the lift generated by the lift-generating member; characterised in that the method comprises the steps of: g) Coupling at least one strain measurement means to the lift load path component; h) Obtaining strain measurements from the at least one strain measurement means; and i) Calculating the lift generated by the lift-generating member from the at least one strain measurements.

Abstract: An improved fin stabilizer control system which has an automatic gain control (AGC) system which uses the difference between the control laws demand signals and the actual fin angles to calculate a gain factor to reduce the control laws demand until the non-linearities almost disappear. If more than one control law is used to generate a demand, the control laws can be prioritized and the available actuator power thus rationed. In particular, the automatic gain control (AGC) sub-system of the control law monitors the motions of the fins and detects when each fin is not following the control law demands. It adjusts the gain of the control law so as to reduce the slew rate limit and the fin angle limit effects.