Abstract: A power margin indicator acquires rotary wing aircraft control parameters which are used to calculate and display a power margin. This calculation takes into account the actual rotor speed and a set point value for the rotor speed in order to determine, regardless of the flight configuration, a power margin which is such that when the rotor speed drops below this set point value, the display indicates that the collective pitch should be reduced until the rotor speed returns to the set point value.

Abstract: The indicator (1) comprises acquisition means (M1, Mn) for acquiring control parameters, calculation means (2) and display means (3). According to the invention, the calculation means (2) take account of the values of the rotor speed and of a set point value for said rotor speed in order to determine, regardless of the flight configuration, a power margin which is such that when the rotor speed drops below said set point value, the display means (3) indicate that the collective pitch should be reduced until the rotor speed returns to the set point value.

Abstract: A flight control indicator for twin-engine aircraft, in particular a rotary-wing aircraft comprising two turboengines for driving at least one rotor, intended to provide the power margin available on the engines of the aircraft as a function of the flight conditions. Display means (6) presents a single dial (8) furnished with two needles (9.sub.1, 9.sub.2), each of them corresponding to a respective engine, and positioned in such a way that, when the engines are operating normally, the two needles are merged.