# US 11,299,286 B2 · System and method for operating a multi-engine aircraft > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,299,286 B2 - Document ID: US11299286B2 - Status: Granted - Kind: B2 - Application number: 16/670,582 - Filed: 2019-10-31 - Published: 2020-11-19 - Granted: 2022-04-12 - Earliest claimed: 2019-05-15 - Assignees: Pratt & Whitney Canada Corp. - Applicants: Pratt & Whitney Canada Corp. - Inventors: Philippe Beauchesne-Martel; Patrick Manoukian - Web page: https://patentgrep.com/patent/US11299286B2 ## CPC - B64D 31/10: for preventing asymmetric thrust - B64C 27/12: Rotor drives - B64C 27/57: automatic or condition responsive, e.g. responsive to rotor speed, torque or thrust - B64D 35/08: characterised by the transmission being driven by a plurality of power plants (for hybrid-electric power plants B64D35/022) - B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT - B64C: AEROPLANES; HELICOPTERS ## Abstract The present disclosure provides methods and systems for operating a rotorcraft comprising a plurality of engines configured to provide motive power to the rotorcraft and at least one rotor coupled to the plurality of engines. Failure of an active engine of the rotorcraft is detected when the rotorcraft is operated in an asymmetric operating regime (AOR), in which at least one first engine of the plurality of engines is the active engine and is operated in an active mode to provide motive power to the rotorcraft and at least one second engine of the plurality of engines is a standby engine and is operated in a standby mode to provide substantially no motive power to the rotorcraft. At least one flight control input is adjusted to compensate for a reduction in rotational speed of the at least one rotor resulting from the failure of the active engine. An increase in a power output of the standby engine of the rotorcraft is commanded. ## Claims ### Claim 1 A method for operating a rotorcraft comprising a plurality of engines configured to provide motive power to the rotorcraft and at least one rotor coupled to the plurality of engines, the method comprising: detecting failure of an active engine of the rotorcraft when the rotorcraft is operated in an asymmetric operating regime (AOR), in which at least one first engine of the plurality of engines is the active engine and is operated in an active mode to provide motive power to the rotorcraft and at least one second engine of the plurality of engines is a standby engine and is operated in a standby mode to provide substantially no motive power to the rotorcraft; adjusting at least one flight control input to compensate for a reduction in rotational speed of the at least one rotor resulting from the failure of the active engine; and commanding an increase in a power output of the standby engine of the rotorcraft. ### Claim 2 (depends on 1) The method of claim 1, further comprising, responsive to commanding the increase in the power output of the standby engine, further adjusting the at least one flight control input. ### Claim 3 (depends on 1) The method of claim 1, wherein adjusting at least one flight control input to compensate for the reduction in rotational speed of the at least one rotor comprises adjusting a blade angle of a plurality of blades of the rotor. ### Claim 4 (depends on 3) The method of claim 3, wherein adjusting the blade angle of the plurality of blades of the rotor comprises adjusting a collective lever input of the rotorcraft. ### Claim 5 (depends on 1) The method of claim 1, wherein adjusting at least one flight control input to compensate for the reduction in rotational speed of the at least one rotor comprises adjusting a pitch angle of the rotorcraft. ### Claim 6 (depends on 5) The method of claim 5, wherein adjusting the pitch angle of the rotorcraft comprises adjusting a cyclic input of the rotorcraft. ### Claim 7 (depends on 1) The method of claim 1, wherein adjusting at least one flight control input comprises adjusting a pedal input of the rotorcraft. ### Claim 8 (depends on 1) The method of claim 1, wherein adjusting the at least one flight control input comprises commanding an automatic flight control system (AFCS) of the rotorcraft to adjust the at least one flight control input. ### Claim 9 (depends on 1) The method of claim 1, wherein detecting the failure of the active engine comprises detecting a negative acceleration for the active engine beyond an acceleration threshold. ### Claim 10 (depends on 1) The method of claim 1, wherein detecting the failure of the active engine comprises detecting a reduction in the speed of the active engine below a speed threshold. ### Claim 11 A system for mitigating active engine failure in an rotorcraft comprising a plurality of engines configured to provide motive power to the rotorcraft and at least one rotor coupled to the plurality of engines, the system comprising: a processing unit; and a non-transitory computer-readable medium having stored thereon program instruction executable by the processing unit for: detecting failure of an active engine of the rotorcraft when the rotorcraft is operated in an asymmetric operating regime (AOR), in which at least one first engine of the plurality of engines is the active engine and is operated in an active mode to provide motive power to the rotorcraft and at least one second engine of the plurality of engines is a standby engine and is operated in a standby mode to provide substantially no motive power to the rotorcraft; adjusting at least one flight control input to compensate for a reduction in rotational speed of the at least one rotor resulting from the failure of the active engine; and commanding an increase in a power output of the standby engine of the rotorcraft. ### Claim 12 (depends on 11) The system of claim 11, wherein the program instructions are further executable for, responsive to commanding the increase in the power output of the standby engine, further adjusting the at least one flight control input. ### Claim 13 (depends on 11) The system of claim 11, wherein adjusting at least one flight control input to compensate for the reduction in rotational speed of the at least one rotor comprises adjusting a blade angle of a plurality of blades of the rotor. ### Claim 14 (depends on 13) The system of claim 13, wherein adjusting the blade angle of the plurality of blades of the rotor comprises adjusting a collective lever input of the rotorcraft. ### Claim 15 (depends on 11) The system of claim 11, wherein adjusting at least one flight control input to compensate for the reduction in rotational speed of the at least one rotor comprises adjusting a pitch angle of the rotorcraft. ### Claim 16 (depends on 15) The system of claim 15, wherein adjusting the pitch angle of the rotorcraft comprises adjusting a cyclic input of the rotorcraft. ### Claim 17 (depends on 11) The system of claim 11, wherein adjusting at least one flight control input comprises adjusting a pedal input of the rotorcraft. ### Claim 18 (depends on 11) The system of claim 11, wherein adjusting the at least one flight control input comprises commanding an automatic flight control system (AFCS) of the rotorcraft to adjust the at least one flight control input. ### Claim 19 (depends on 11) The system of claim 11, wherein detecting the failure of the active engine comprises detecting a negative acceleration for the active engine beyond an acceleration threshold. ### Claim 20 (depends on 11) The system of claim 11, wherein detecting the failure of the active engine comprises detecting a reduction in the speed of the active engine below a speed threshold.