Abstract: A method of controlling a group (2) of engines developing a necessary power (Wnec) for driving a rotor (3), said group (2) of engines having at least one electrical member (4), electrical energy storage means (5), and a first number n of engines (6) that is greater than or equal to two. A processor unit (10) executes instructions for evaluating a main condition as to whether the group of engines can develop the necessary power while resting one engine, and if so for resting one engine and accelerating a second number engines not at rest, and for causing the electrical member to operate in motor mode, if necessary, the electrical member operating temporarily in electricity generator mode when the storage means are discharged.

Abstract: A method of managing an engine failure on a rotary wing aircraft (1) having a hybrid power plant (5) with at least two fuel-burning engines (13, 13?), at least one electric machine (12), and a main gearbox (11). Said aircraft (1) also has electrical energy storage means (14) and a main rotor (2) mechanically connected to said hybrid power plant (5). In said method, during each flight, the operation of said engines (13, 13?) is monitored in order to detect a failure of any one of them, and then once a failure of one of said engines (13, 13?) has been detected, said electric machine (12) is controlled, if necessary, to deliver auxiliary power We in order to avoid a deficit appearing in the total power WT of said hybrid power plant (5), thereby enabling the pilot of said aircraft (1) to fly said aircraft (1) safely without degrading said hybrid power plant (5).

Abstract: A method of managing an engine failure on a rotary wing aircraft (1) having a hybrid power plant (5) with at least two fuel-burning engines (13, 13?), at least one electric machine (12), and a main gearbox (11). Said aircraft (1) also has electrical energy storage means (14) and a main rotor (2) mechanically connected to said hybrid power plant (5). In said method, during each flight, the operation of said engines (13, 13?) is monitored in order to detect a failure of any one of them, and then once a failure of one of said engines (13, 13?) has been detected, said electric machine (12) is controlled, if necessary, to deliver auxiliary power We in order to avoid a deficit appearing in the total power WT of said hybrid power plant (5), thereby enabling the pilot of said aircraft (1) to fly said aircraft (1) safely without degrading said hybrid power plant (5).

Abstract: A method of controlling a group (2) of engines developing a necessary power (Wnec) for driving a rotor (3), said group (2) of engines having at least one electrical member (4), electrical energy storage means (5), and a first number n of engines (6) that is greater than or equal to two. A processor unit (10) executes instructions for evaluating a main condition as to whether the group of engines can develop the necessary power while resting one engine, and if so for resting one engine and accelerating a second number engines not at rest, and for causing the electrical member to operate in motor mode, if necessary, the electrical member operating temporarily in electricity generator mode when the storage means are discharged.