Method and a device for assisting the piloting of an aircraft, and an aircraft

A device for assisting the piloting of an aircraft comprising a first rotor having a plurality of first blades with a first variable collective pitch, and a second rotor having a plurality of second blades with a second variable collective pitch, said aircraft having a power plant provided with at least one engine operating in a plurality of ratings, said device including measurement sensors for measuring a plurality of predetermined monitoring parameters of the power plant, wherein the device comprises first measurement means for measuring the first collective pitch and second measurement means for measuring the second collective pitch together with display means connected to a computer, said device including an index controlled by said computer and pointing on the display means to said first collective pitch and to said second collective pitch in a diagram having a first axis and a second axis that are graduated in collective pitch units relating respectively to the first collective pitch and to the second collective pitch, said computer using said measurement sensors to determine at least one available power margin of the engine corresponding to the power to be supplied in order to cause a limiting parameter to reach a limit associated with one of said ratings so as to display one available power limit curve per power margin in said diagram, thereby informing the pilot of the first collective pitch margin and of the second collective pitch margin that are available before reaching the limit of at least one rating.

A method of assisting the piloting of an aircraft, the aircraft comprising a first rotor having a first plurality of blades with a first variable collective pitch, a second rotor having a second plurality of blades with a second variable collective pitch, a power plant having a plurality of engines, and a computer monitoring a plurality of power plant parameters, wherein the computer performs the following steps:

• monitoring a plurality of power plant parameters;
• determining an instantaneous first collective pitch of the first rotor and an instantaneous second collective pitch of the second rotor;
• determining a limiting parameter corresponding to one of the plurality of power plant parameters that is closest to an instantaneous operating limit;
• determining an available power margin corresponding to an engine power required to cause the limiting parameter to reach the operating limit;
• determining a power limit curve associated with the available power margin;
• displaying the power limit curve associated with the engine having the limiting parameter that is closest to its operating limit and an index indicating the first collective pitch and the second collective pitch on a diagram on a computer monitor to indicate first and second collective pitch margins, the diagram having first and second axes that are graduated in collective pitch units relating respectively to the first collective pitch and to the second collective pitch, the index being displayed at an intersection of the first and second axes;
• and
• displaying a predictive pointer in the diagram, the pointer serving at the beginning of the maneuver to present the first and second collective pitches that the aircraft ought to reach at the end of said maneuver.