초록 ▼

A method of assisting a pilot of a single-engined rotary wing aircraft (1) during a stage of flight in autorotation, said aircraft (1) including a hybrid power plant having an engine (13), an electric machine (12), and a main gearbox (11). Said aircraft (1) also includes electrical energy storage me

A method of assisting a pilot of a single-engined rotary wing aircraft (1) during a stage of flight in autorotation, said aircraft (1) including a hybrid power plant having an engine (13), an electric machine (12), and a main gearbox (11). Said aircraft (1) also includes electrical energy storage means (14) and a main rotor (2) mechanically connected to said hybrid power plant (5). According to said method, while in flight, the operation of said engine (13) is monitored in order to detect a failure thereof, in particular by monitoring for a drop of power on said main rotor (2), and then in the event of a failure of said engine (13) being detected, said electric machine (12) is controlled to deliver auxiliary power We to said main rotor (2), thereby enabling the pilot of said aircraft (1) to be assisted in maneuvering said aircraft (1) during said stage of flight in autorotation following said failure.

대표청구항 ▼

1. A method of assisting a pilot of a rotary wing aircraft during a stage of flight in autorotation, said aircraft comprising: a hybrid power plant having a single engine, at least one electric machine, and a main gearbox;at least one electrical energy storage means; andat least one main rotor that

1. A method of assisting a pilot of a rotary wing aircraft during a stage of flight in autorotation, said aircraft comprising: a hybrid power plant having a single engine, at least one electric machine, and a main gearbox;at least one electrical energy storage means; andat least one main rotor that is driven in flight at a nominal speed of rotation NrN by said hybrid power plant;the method being characterized by the following steps:during a monitoring step, measuring in flight a monitoring parameter of said aircraft in order to detect a failure, if any, of said engine; andwhen a failure of said engine is detected, controlling said electric machine to deliver auxiliary power We to said main rotor, thereby assisting said pilot of said aircraft in maneuvering said aircraft during said stage of flight in autorotation following said failure. 2. A method according to claim 1, wherein, for said aircraft having first measurement means for measuring an instantaneous speed of rotation Nr of said main rotor, said instantaneous speed of rotation Nr is measured during said monitoring step in order to evaluate a drop of power of said main rotor representative of said failure of said engine. 3. A method according to claim 2, wherein a derivative dNr/dt of said instantaneous speed of rotation Nr is determined during said monitoring step. 4. A method according to claim 3, that is considered that said engine has failed when a check power WC is positive, said check power WC being obtained using the following first relationship: WC=WmaxNrt⁢⁢1-Nrt⁢⁢2⁢(Nr+k⁢ⅆNrⅆt-Nrt⁢⁢2) Wmax being the maximum power that can be delivered by said electric machine, Nr being said instantaneous speed of rotation of said main rotor, dNr/dt being the derivative of said instantaneous speed of rotation Nr, and Nrt1, Nrt2, and k being positive coefficients that depend on said aircraft, Nrt1 being less than Nrt2. 5. A method according to claim 4, wherein said coefficient Nrt1 lies in the range 82.5% to 88% of the nominal speed of rotation NrN, and said coefficient Nrt2 lies in the range 93% to 98.5% of said nominal speed of rotation NrN. 6. A method according to claim 1, wherein for said engine being a turboshaft engine having second measurement means for measuring an instantaneous speed of rotation NG of a compression turbine of said engine, it is considered that said engine has failed when the check power WC is positive, said check power WC being obtained using the following second relationship: WC=WmaxNGt⁢⁢1-NGt⁢⁢2⁢(NG+k′⁢ⅆNGⅆt-NGt⁢⁢2) Wmax being the maximum power that can be delivered by said electric machine, NG being said instantaneous speed of rotation of said compression turbine, dNG/dt being the derivative of said instantaneous speed of rotation NG, and NGt1, NGt2, and k′ being positive coefficients depending on said aircraft, NGt1 being less than NGt2. 7. A method according to claim 1, wherein for said aircraft having third measurement means for measuring an outlet torque from said engine, during said monitoring step, said torque is measured in order to evaluate a drop in power from said engine representative of said failure of said engine. 8. A method according to claim 4, wherein said auxiliary power We is equal to said check power WC when said check power WC is less than said maximum power Wmax, and said auxiliary power We is equal to said maximum power Wmax when said check power WC is greater than or equal to said maximum power Wmax. 9. A method according to claim 1, wherein for said aircraft having display means, there is displayed on said display means information relating to said available auxiliary power We together with an indication indicating whether said method is in operation. 10. A method according to claim 9, wherein said information is the remaining time for utilization of said auxiliary power We at the maximum power Wmax that can be delivered by said electric machine. 11. A method according to claim 1, wherein said method is in operation only while said aircraft is in flight, with information means indicating that said aircraft has taken off. 12. A method according to claim 1, wherein said method is in operation only when said aircraft is below a predetermined height above the ground. 13. A rotary wing aircraft comprising: a device for assisting a pilot of said aircraft during a stage of flight in autorotation, the device being provided with:a hybrid power plant comprising a single engine, at least one electric machine, and a main gearbox;at least one storage means for storing electrical energy; andcontrol means for controlling said electric machine, the control means having a memory; andat least one main rotor driven in rotation by said power plant and rotating at an instantaneous speed of rotation Nr;wherein the aircraft includes monitor means for monitoring a monitoring parameter of said aircraft in order to detect a failure, if any, of said engine, said control means communicating with said monitor means and with said electric machine in order to perform the method according to claim 1. 14. An aircraft according to claim 13, wherein said monitor means comprise measurement means for evaluating a drop in the power of said main rotor. 15. An aircraft according to claim 13, wherein said monitor means comprise first measurement means for measuring said instantaneous speed of rotation Nr in order to evaluate a drop of power of said main rotor. 16. An aircraft according to claim 13, wherein said control means comprise a calculation unit and a memory, said calculation unit executing instructions stored in said memory in order to determine whether there is a failure of said engine, and then to cause said electric machine, where appropriate, to deliver auxiliary power We to said main rotor, thereby enabling said pilot of said aircraft to be assisted in maneuvering said aircraft during said stage of flight in autorotation following said failure. 17. An aircraft according to claim 13, wherein said aircraft includes display means for displaying information relating to said available auxiliary power We, together with an indication indicating whether said device is in operation.