Abstract: The present invention relates to A power margin indicator device constituting a first limitation indicator for a rotorcraft, for providing a pilot of said rotorcraft with information about a power margin available on at least one engine and a main power transmission gearbox of said rotorcraft as a function of flying conditions, said device comprising: input means for collecting input data corresponding various operating parameters of said at least one engine and of said MGB; calculation means connected to said input means, said calculation means serving to determine a collective pitch margin for the blades of a rotor of said rotorcraft; and display means presenting said collective pitch margin.

Abstract: A method of assisting the piloting of an aircraft, such as a helicopter, includes determining a limiting power margin of a power plant of the aircraft relative to a power limit at an operating rating of an engine of the power plant. The limiting power margin is transformed into a collective pitch margin for the operating rating. The collective pitch margin represents the margin between a current collective pitch of blades of a main rotor of the aircraft and a collective pitch limit of the blades of the main rotor. The collective pitch limit is determined and then displayed on a display of the aircraft for a pilot to view.

Abstract: The present invention relates to A power margin indicator device constituting a first limitation indicator for a rotorcraft, for providing a pilot of said rotorcraft with information about a power margin available on at least one engine and a main power transmission gearbox of said rotorcraft as a function of flying conditions, said device comprising: input means for collecting input data corresponding various operating parameters of said at least one engine and of said MGB; calculation means connected to said input means, said calculation means serving to determine a collective pitch margin for the blades of a rotor of said rotorcraft; and display means presenting said collective pitch margin.

Abstract: A method of assisting the piloting of an aircraft. A collective pitch margin of a main rotor is determined by applying a recursive algorithm using a main relationship that supplies said collective pitch margin at each current calculation instant as a function of the quotient of a limiting power margin divided by a denominator, the denominator being equal to the product of a first term multiplied by a second term, the first term being a function of the current collective pitch at said current calculation instant and of the collective pitch limit at a previous calculation instant prior to said current calculation instant, said second term being a function at least of a predetermined coefficient for reducing said power margin of the power plant.