A rotary-wing aircraft equipped with a flight control system to improve rotary-wing aircraft control when a stop occurs in mid-flight in an asymmetric flight regime mode.

Abstract

The present invention provides a rotary-wing aircraft having a main rotor with at least one main rotor actuator, a series actuator positioned upstream of the main rotor actuator, an engine for supplying power to the main rotor, and a flight control system for controlling flight maneuvers in AEO mode or AFR mode. [Solution] The flight control system includes control logic configured to pre-adjust the series actuator when entering AFR mode in order to enable control of the rotary-wing aircraft in the event of an IFSD. The pre-adjustment of the series actuator includes shifting the approved reduced nominal stroke range of the series actuator stroke in AEO mode to the approved reduced shifted stroke range of the series actuator stroke in AFR mode, thereby enabling approval of an extended stroke range that provides sufficient control authority for recovery operations in the event of an IFSD.

Claims

1. A rotary-wing aircraft (100), At least one main rotor (110) comprising at least one main rotor actuator (114) for adapting main rotor control according to the current flight state of the rotor-wing aircraft (100), wherein the main rotor actuator stroke of the at least one main rotor actuator (114) is adjusted via the series actuator stroke (205c, 315c, 325c) of at least one series actuator (205, 315, 325) located upstream of the at least one main rotor actuator (114), and the at least one series actuator (205, 315, 325) is coupled to a control lever (301) connected to at least one parallel actuator (375), At least one first engine (192) and at least one second engine for supplying power to at least one main rotor blade (110), A flight control system (160) configured to control the flight operation of the rotor-wing aircraft (100) in an all-engine-operated (AEO) mode in which at least one first engine (192) and at least one second engine supply power to the at least one main rotor (110), or in an asymmetric flight regime (AFR) mode in which only the at least one first engine (192) supplies power to the at least one main rotor (110), Control logic (165) configured to pre-adjust the at least one series actuator (205, 315, 325) when entering the AFR mode, in order to enable control of the rotary-wing aircraft in the event of an in-flight shutdown (IFSD) of the at least one first engine (192) in the AFR mode, wherein the pre-adjustment of the at least one series actuator (205, 315, 325) is approved in the AEO mode for the series actuator stroke (205c) of the at least one series actuator (205). A flight control system (160) includes control logic (165) which includes shifting the reduced nominal stroke range (212) to a reduced shift stroke range (216) approved for the series actuator stroke (205c) of the at least one series actuator (205) in AFR mode, thereby enabling approval of an extended stroke range (214) in the event of an IFSD, wherein the extended stroke range (214) is adapted to provide sufficient control authority necessary for recovery operations in response to an IFSD, A rotary-wing aircraft (100) equipped with [a specific feature].

2. The rotary-wing aircraft (100) according to claim 1, wherein the pre-adjustment of the at least one series actuator (205) when entering the AFR mode includes expanding the reduced shift stroke range (216) of the series actuator stroke (205c) to the maximum available stroke range (210) for providing full available control authority when an IFSD occurs.

3. The rotary-wing aircraft (100) according to claim 1, wherein the pre-adjustment of the at least one series actuator (205) when entering the AFR mode includes shifting the neutral stroke position (215) of the at least one series actuator (205) to the maximum shift neutral stroke position (227) to provide full available control authority in the event of an IFSD, and adjusting the at least one parallel actuator (375) to compensate for the shift of the neutral stroke position (215) of the at least one series actuator (205).

4. The control logic is configured to set the neutral stroke position (215) of the series actuator stroke (205c) of the at least one series actuator (205) within the maximum available stroke range (210), The neutral stroke position (215) is the central stroke position of the AEO mode, which evenly divides the maximum usable stroke range (210) into two maximum usable stroke regions (210a, 210b) for strokes in two opposite stroke directions (201, 202). The rotary-wing aircraft (100) according to claim 1, wherein the reduced nominal stroke range (212) includes two reduced approved stroke ranges (212a, 212b) that are smaller than the two maximum usable stroke ranges (210a, 210b).

5. The pre-adjustment of the at least one series actuator (205) when entering the AFR mode includes limiting the maximum available stroke range (210) to the reduced shift stroke range (216) of the AFR mode until an IFSD occurs in the at least one first engine (192) in the AFR mode. The rotary-wing aircraft (100) according to claim 1, wherein the reduced shift stroke range (216) is smaller than the maximum usable stroke range (210) and preferably equal to the reduced nominal stroke range (212).

6. The pre-adjustment of the at least one series actuator (205) when entering the AFR mode includes shifting the neutral stroke position (215) of the series actuator stroke (205c) of the at least one series actuator (205) from the central stroke position in the AEO mode to the shift stroke position (225) in the AFR mode. The rotary-wing aircraft (100) according to claim 4, wherein the shift stroke position (225) is adapted to enable an expansion of control authority for the main rotor blades in order to enable necessary recovery operations in response to the occurrence of an IFSD.

7. The rotary-wing aircraft (100) according to claim 5, wherein the reduced shift stroke range (216) is evenly divided into two shift stroke regions (235m, 235n) by the shift neutral stroke position (225) of the series actuator stroke (205c) of at least one series actuator (205).

8. The rotary-wing aircraft (100) according to claim 6, wherein the control logic (165) is configured to pre-adjust the at least one parallel actuator (375) when entering the AFR mode, by adjusting the current parallel actuator position (375m, 375n) of the at least one parallel actuator (375) to compensate for the shift of the neutral stroke position (215) of the series actuator stroke (205c) of the at least one series actuator (205) in the AFR mode, enabling rotary-wing aircraft control when an IFSD occurs in the at least one first engine (192).

9. To compensate for the shift, adapting the current parallel actuator position (375m, 375n) of the at least one parallel actuator (375) includes moving the neutral control position (310) of the control lever (301) from the nominal neutral control position (311) in AEO mode to a shift neutral control position (312) in AFR mode that is different from the nominal neutral control position (311), The rotary-wing aircraft (100) according to claim 8, wherein the shift neutral control position (312) is adapted to allow the series actuator stroke (315c, 325c) of the at least one series actuator (315, 325) using extended authority.

10. The rotary-wing aircraft (100) according to claim 1, wherein the control logic (165) is configured to adapt force feedback to the pilot of the rotary-wing aircraft (100) via the associated force characteristics of the parallel actuators (375).

11. The at least one series actuator (315, 325) includes a first series actuator (315) and a second series actuator (325), The pre-adjustment of the at least one series actuator (315, 325) is as follows: To maximize the first approved stroke range of the first series actuator stroke (315c) of the first series actuator (315) from the first reduced nominal stroke range (315d) approved in AEO mode to the first maximum usable stroke range (315e) approved when IFSD occurs, To maximize the second approved stroke range of the second series actuator stroke (325c) of the second series actuator (325) from the second reduced nominal stroke range (325d) approved in AEO mode to the second maximum usable stroke range (325e) approved when IFSD occurs, A rotary-wing aircraft (100) according to claim 1, including the above.

12. The reduced shift stroke range (216) of the series actuator stroke (205c, 315c, 325c) of the at least one series actuator (205, 315, 325) for controlling the flight operation of the rotary-wing aircraft in the AFR mode until an IFSD occurs is provided solely by the first maximum available stroke range (315e) of the first series actuator (315), according to claims 5 and 11, for the rotary-wing aircraft (100).

13. The control logic is configured to enable the series actuator strokes (205c, 315c, 325c) of at least one series actuator (205, 315, 325) to be operated within both the first maximum usable stroke range (315e) and the second maximum usable stroke range (325e) in order to control the flight operation of the rotary-wing aircraft (100) in response to the occurrence of IFSD in the AFR mode, according to claim 12.

14. A flight control system (160) for a rotary-wing aircraft (100), comprising at least one main rotor (110) with at least one main rotor actuator (114) for adapting the main rotor control according to the current flight state of the rotary-wing aircraft (100), The stroke of the main rotor actuator of the at least one main rotor actuator (114) is adjusted via the series actuator strokes (205c, 315c, 325c) of at least one series actuator (205, 315, 325) located upstream of the at least one main rotor actuator (114). The at least one series actuator (205, 315, 325) is coupled to a control lever (301) connected to at least one parallel actuator (375), and at least one first engine (192) and at least one second engine are provided to supply power to the at least one main rotor blade (110). The flight control system (160) is configured to control the flight operation of the rotorcraft (100) in at least an all-engine-operated (AEO) mode in which at least one first engine (192) and at least one second engine supply power to the at least one main rotor (110), or in an asymmetric flight regime (AFR) mode in which only the at least one first engine (192) supplies power to the at least one main rotor (110). In order to enable control of the rotary-wing aircraft in the event of an in-flight shutdown (IFSD) of at least one first engine (192) in the AFR mode, the system includes a control logic (165) configured to pre-adjust the at least one series actuator (205, 315, 325) when the system enters the AFR mode, The pre-adjustment of the at least one series actuator (205, 315, 325) includes shifting the approved reduced nominal stroke range (212) of the series actuator stroke (205c) of the at least one series actuator (205) in AEO mode to the approved reduced shift stroke range (216) of the series actuator stroke (205c) of the at least one series actuator (205) in AFR mode, thereby enabling approval of the expanded stroke range (214) when an IFSD occurs. The extended stroke range (214) is adapted to provide sufficient control authority for recovery operations in response to the occurrence of an IFSD, and includes a flight control system (160) including control logic (165).

15. A method for controlling the flight motion of a rotary-wing aircraft (100), The aforementioned rotary-wing aircraft (100) At least one main rotor (110) comprising at least one main rotor actuator (114) for adapting main rotor control according to the current flight state of the rotor-wing aircraft (100), wherein the main rotor actuator stroke of the at least one main rotor actuator (114) is adjusted via the series actuator stroke (205c, 315c, 325c) of at least one series actuator (205, 315, 325) located upstream of the at least one main rotor actuator (114), and the at least one series actuator (205, 315, 325) is coupled to a control lever (301) connected to at least one parallel actuator (375), At least one first engine (192) and at least one second engine for supplying power to the at least one main rotor blade (110), The aircraft comprises a flight control system (160) configured to control the flight operation of the rotorcraft (100) in an all-engine-operated (AEO) mode in which at least one first engine (192) and at least one second engine power the at least one main rotor (110), or in an asymmetric flight regime (AFR) mode in which only the at least one first engine (192) powers the at least one main rotor (110), The method includes providing control logic (165) configured to pre-tune the at least one series actuator (205, 315, 325) when entering the AFR mode, in order to enable control of the rotary-wing aircraft in the event of an in-flight shutdown (IFSD) of the at least one first engine (192) in the AFR mode. The pre-adjustment of the at least one series actuator (205, 315, 325) includes shifting the approved reduced nominal stroke range (212) of the series actuator stroke (205c) of the at least one series actuator (205) in AEO mode to the approved reduced shift stroke range (216) of the series actuator stroke (205c) of the at least one series actuator (205) in AFR mode, thereby enabling approval of the expanded stroke range (214) when an IFSD occurs. The method wherein the extended stroke range (214) is adapted to provide sufficient control authority necessary for recovery operations in response to the occurrence of an IFSD.

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