Helicopter power available to hover indicator

Claim 1

Apparatus for indicating power available for hovering a helicopter having a power plant including at least one engine, comprising: transducer means for providing parameter signals, each parameter signal being indicative of a related current aircraft condition; signal processing means, for providing in response to a first plurality of parameter signals, a ratio signal indicative of the relation between the power required during forward flight at the current airspeed and the power required to hover under the same rotor, engine, weight and atmospheric conditions, and for providing, in response to a second plurality a parameter signals, a current operating power signal indicative of current power being supplied by the engine to the aircraft, and for providing, in response to said current operating power signal and said ratio signal, a power required to hover signal indicative of the power required to execute a hover maneuver under the present rotor, engine, weight and atmospheric conditions, and for providing, in response to a third plurality of said parameter signals, a maximum power signal adaptively updated to be indicative, according to an adaptive engine model, of the maximum power which can currently be supplied under current engine and atmospheric conditions by the presently operating helicopter power plant, and for providing, in response to said power required to hover signal and said maximum power signal, a remaining power signal indicative of the power currently remianing which can be supplied by the power plant, and for providing, in response to said remaining power signal and to said power required to hover signal, a hover power signal indicative of the ratio between the remaining power signal and the power required to hover signal; and a power indicator, responsive to the hover power signal, for displaying the magnitude thereof.