Patent ID: 6411869
Filing Date: 2002-06-25
Classification: B64D

Abstract:
A power margin indicator for a rotary wing aircraft comprising at least one main lift and forward travel rotor, said indicator, which is intended to provide information about a power margin available on at least one engine and at least one engine and at least one gearbox of said aircraft, comprising:acquisition means which determine values of control parameters for control of the at least one engine and the at least one gearbox; calculation means which, on the basis of said values of the control parameters determined by said acquisition means and of limit values regarding said control parameters for various engine speeds of said at least one engine, determines for each of said engine speeds a power margin, each said power margin being determined for a corresponding one of said engine speeds with respect to a first limit which corresponds to a first one of the limit values which would be reached by one of the control parameters if the power were to vary; and display means which display said first one of said limit values on a display screen for at least some of said engine speeds, said first one of said limit values being represented on a scale that is graduated in collective pitch equivalents and capable of scrolling past a fixed pointer which indicates a current collective pitch, a difference in terms of collective pitch between said pointer and said first one of said limit values being representative of a corresponding power margin, wherein said acquisition means determine values of a speed of said rotor, and wherein said calculation means take account of said values of said speed of said rotor and of at least one rotor speed set point value to determine, regardless of flight configuration, at least one power margin which is such that when the speed of said rotor drops below said set point value, the corresponding first one of said limit values which is displayed by the display means indicates to a pilot of the aircraft that the collective pitch should be reduced until the speed of said rotor returns to said set point value.