Method of assistance to the navigation of a rotorcraft multi-engined in the event of engine failure, in the context of a variable speed drive has a main rotor of the rotorcraft

摘要

A method of assisting the piloting of a multi-engined rotorcraft in the event of an engine failure. A main rotor of the rotorcraft is driven at a variable NR speed under the control of a control unit. Calculation means identify an authorized margin of mechanical power usable by the pilot depending on a rating for regulating the operation of each of the engines under the control of a regulator unit. Outside an engine-failure situation, and providing the main rotor is being driven at a low NR speed, the mechanical power margin that is usable by the pilot and that is displayed on a screen, is in fact a limited margin of a value less than the authorized margin. Under such conditions, and in an engine-failure situation, the mechanical power reserve that is actually available enables the pilot to counter rapidly the sudden drop in the NR speed of rotation of the main rotor as induced by the engine failure.