Patent ID: 11859563
Assignee: PRATT & WHITNEY CANADA CORP.
Field: Transport (Mechanical engineering)
Classification: CPC F  B  Y | IPC B  F

Claim 17:
18. An aircraft, comprising:
a first engine having a bleed air system with a first common bleed air conduit, the first engine having an active mode when the aircraft is in flight at an altitude above ground;
a second engine having a bleed air system with a second common bleed air conduit, the second engine having an active mode when the aircraft is in flight at the altitude above the ground and a standby mode when the aircraft is in flight at the altitude above ground, a power output of the second engine greater in the active mode than in the standby mode, in the standby mode, the second engine is operating, receives a fuel flow, and provides substantially no motive power to the aircraft;
at least one control valve disposed fluidly between the first and second common bleed air conduits, the at least one control valve operable to:
i) fluidly connect the first common bleed air conduit to the second common bleed air conduit when the second engine is in the standby mode and when the first engine is in the active mode; and
ii) fluidly disconnect the first common bleed air conduit from the second common bleed air conduit when the first engine and the second engine are in the active mode; and

a source of pressurized air that is external to the first engine and/or to the second engine, the source of pressurized air being selectively fluidly connectable to the bleed air system of the first engine and/or of the second engine;
wherein each of the first engine and the second engine comprises:
a first bleed air conduit, a second bleed air conduit;
each of the first and second common bleed air conduits fluidly connected to both of the first and second bleed air conduits of their respective engine; and
a check valve disposed fluidly between the second bleed air conduit and the first or second common bleed air conduit of a respective engine, and operable to prevent air flowing from the second bleed air conduit to the first or second common bleed air conduit.