Patent ID: 11920479
Assignee: PRATT & WHITNEY CANADA CORP.
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F  B  Y | IPC B  F

Claim 0:
1. A method of operating a multi-engine system of a rotorcraft, the multi-engine system including a first engine, a second engine, and a gearbox drivingly coupling the first and second engines to a rotor of the rotorcraft, the method comprising:
during a cruise flight segment of the rotorcraft, controlling the first engine to operate in an active mode wherein the first engine provides and maintains a first power output, and driving the gearbox with the first engine producing the first power output thereby powering the rotorcraft to maintain the cruise flight segment; and
during the cruise flight segment of the rotorcraft and while the first engine remains in the active mode, controlling the second engine to operate in a standby mode, wherein the second engine transmits a second power output to the common gearbox that is less than the first power output, by: modulating a set of variable guide vanes (VGVs) upstream of a low pressure compressor of the second engine to restrict airflow into the second engine; providing a fuel flow to the second engine that is between 80% and 99.5% less than a fuel flow provided to the first engine; and driving the gearbox with the second engine producing the second power output;
wherein the second power output provided by the second engine to the common gearbox, when the second engine is operating in the standby mode, is greater than 0% and less than 1% of a rated full-power of the second engine.