Abstract: An aircraft power plant has a hybrid propulsion system having an electric motor, an output shaft drivingly connectable to a thrust generator, a combustion engine, a compressor, and a planetary gear train having an Auxiliary Power Unit (APU) mode in which the electric motor is in driving engagement with the compressor via the planetary gear train while the combustion engine is disengaged from the output shaft, and a propulsion mode in which the combustion engine and the electric motor are in driving engagement with the output shaft via the planetary gear train.

Abstract: A variable geometry inlet system of an aircraft engine includes an inlet duct. The inlet duct includes at least first and second sections moveable between extended and retracted positions such that the inlet duct defines a variable axial length of an inlet passage for selective flight conditions. The inclusion of acoustic treatment may assist in controlling noise.

Abstract: A control system for a hybrid electric powerplant of an aircraft can include a master controller configured to receive one or more power settings and to output a heat engine setting and an electric motor setting and a heat engine controller operatively connected to the master controller. The heat engine controller can be configured to receive the heat engine setting and to control a heat engine system as a function of the heat engine setting to control torque output by a heat engine. The system can include an electric motor controller operatively connected to the master controller. The electric motor controller configured to receive the electric motor engine setting and to control an electric motor system as a function of the electric motor setting to control torque output by an electric motor.

Abstract: An auxiliary power unit for an aircraft, having a compressor, an intercooler including first conduit(s) having an inlet in fluid communication with the compressor outlet and second conduit(s) configured for circulation of a coolant therethrough, an engine core having an inlet in fluid communication with an outlet of the first conduit(s), and a bleed conduit in fluid communication with the outlet of the first conduit(s) through a bleed air valve. The auxiliary power unit may include a generator in driving engagement with the shaft of the engine core to provide electrical power for the aircraft. A method of providing compressed air and electrical power to an aircraft is also discussed.

Abstract: An aircraft navigational system for a multiengine aircraft can include a flight planning module configured to receive two or more navigational points defining a route and determine if a first degraded operation ceiling is high enough to travel along the route based on obstacle data defining relative location of one or more obstacles and one or more obstacle clearance standards. The module can be configured to receive a status and/or performance limitation of an electric motor system of the aircraft. The module can be configured to determine if the electric motor system is or will be able to provide temporary additional power to produce a second degraded operation ceiling for at least a required time based on the status and/or performance limitation of the electric motor system if the first degraded operation ceiling is not high enough to permit travel along the route.

Abstract: An aircraft power plant has: an electric motor; a compressor; a combustion engine; an output shaft drivingly engageable to a thrust generator for propelling an aircraft equipped with the aircraft power plant; and a transmission including a gearbox having a first input drivingly engaged by the electric motor, a first output drivingly engaging the compressor, a second input drivingly engageable by the combustion engine, and a second output drivingly engageable to the output shaft, wherein the transmission has: a propulsion configuration in which the output shaft and the compressor are drivingly engaged to the electric motor and to the combustion engine via the gearbox, and an auxiliary power unit configuration in which the combustion engine and the output shaft are at rest while the electric motor drivingly engages the compressor.

Abstract: There is described a method and system for in-flight start of an engine. The method comprises rotating a propeller; generating electrical power at an electric generator embedded inside a propeller hub from rotation of the propeller; transmitting the electrical power from the electric generator to an engine starter mounted on a core of the engine via an electric power link; and driving the engine with the engine starter to a sufficient speed while providing fuel to a combustor to light the engine to achieve self-sustaining operation of the engine.

Abstract: A method of providing active flow control for an aircraft includes cooling a liquid coolant in a heat exchanger by circulating a cooling airflow through the heat exchanger, and providing fluid communication between the cooling airflow and a boundary layer flow of at least one flight control surface of the aircraft. The cooling airflow affects the boundary layer flow of the flight control surface(s) to provide active flow control. A method of cooling an engine core of an engine assembly includes circulating a cooling fluid through the engine core, and cooling the cooling fluid with a cooling airflow used to provide active flow control to a flight control surface of the aircraft. An active flow control system for an aircraft is also discussed.

Abstract: An aircraft power plant has a hybrid propulsion system having an electric motor, a combustion engine, an output shaft drivingly connectable to a thrust generator, a compressor, and a transmission having a first transmission drive path and a second transmission drive path, the combustion engine and the output shaft in driving engagement with the first transmission drive path, the electric motor selectively drivingly engageable to the compressor via either the first drive path or via the second drive path.

Abstract: A compound engine assembly for use as an auxiliary power unit for an aircraft and including an engine core with internal combustion engine(s), a compressor having an outlet in fluid communication with an engine core inlet, a bleed conduit in fluid communication with the compressor outlet through a bleed air valve, and a turbine section having an inlet in fluid communication with the engine core outlet and configured to compound power with the engine core. The turbine section may include a first stage turbine having an inlet in fluid communication with the engine core outlet and a second stage turbine having an inlet in fluid communication the first stage turbine outlet. A method of providing compressed air and electrical power to an aircraft is also discussed.

Abstract: An aircraft power plant has: an electric motor; a compressor; a combustion engine; an output shaft drivingly engageable to a thrust generator for propelling an aircraft equipped with the aircraft power plant; and a transmission including a gearbox having a first input drivingly engaged by the electric motor, a first output drivingly engaging the compressor, a second input drivingly engageable by the combustion engine, and a second output drivingly engageable to the output shaft, wherein the transmission has: a propulsion configuration in which the output shaft and the compressor are drivingly engaged to the electric motor and to the combustion engine via the gearbox, and an auxiliary power unit configuration in which the combustion engine and the output shaft are at rest while the electric motor drivingly engages the compressor.

Abstract: An aircraft heating assembly including an internal combustion engine having a liquid coolant system distinct from any fuel and lubricating system of the engine and including cooling passages in the internal combustion engine for circulating a liquid coolant from a coolant inlet to a coolant outlet, a coolant circulation path outside of the internal combustion engine and in fluid communication with the coolant inlet and the coolant outlet, and a heating element in heat exchange relationship with a portion of the aircraft to be heated. The coolant circulation path extends through a heat exchanger configured to remove a portion of a waste heat from the liquid coolant. The heating element is in heat exchange relationship with the coolant circulation path to receive another portion of the waste heat therefrom. A method of heating a portion of an aircraft is also discussed.

Abstract: There is described a method and system for in-flight start of an engine. The method comprises rotating a propeller; generating electrical power at an electric generator embedded inside a propeller hub from rotation of the propeller; transmitting the electrical power from the electric generator to an engine starter mounted on a core of the engine via an electric power link; and driving the engine with the engine starter to a sufficient speed while providing fuel to a combustor to light the engine to achieve self-sustaining operation of the engine.

Abstract: An aircraft power plant has: a hybrid propulsion system having an electric motor, an output shaft drivingly connectable to a thrust generator, a combustion engine, a compressor, and a transmission having a first transmission drive path and a second transmission drive path selectively engageable to the first transmission drive path, the electric motor and the compressor in driving engagement with the first transmission drive path, the combustion engine and the output shaft in driving engagement with the second transmission drive path.

Abstract: There is described a method and system for in-flight start of an engine. The method comprises rotating a propeller; generating electrical power at an electric generator embedded inside a propeller hub from rotation of the propeller; transmitting the electrical power from the electric generator to an engine starter mounted on a core of the engine via an electric power link; and driving the engine with the engine starter to a sufficient speed while providing fuel to a combustor to light the engine to achieve self-sustaining operation of the engine.

Abstract: A variable geometry inlet system of an aircraft engine includes an inlet duct. The inlet duct includes at least first and second sections moveable between extended and retracted positions such that the inlet duct defines a variable axial length of an inlet passage for selective flight conditions. The inclusion of acoustic treatment may assist in controlling noise.

Abstract: A variable geometry inlet system of an aircraft engine includes an inlet duct. The inlet duct includes at least first and second sections moveable between extended and retracted positions such that the inlet duct defines a variable axial length of an inlet passage for selective flight conditions. The inclusion of acoustic treatment may assist in controlling noise.

Abstract: An auxiliary power unit for an aircraft includes a rotary intermittent internal combustion engine drivingly engaged to an engine shaft, a turbine section having an inlet in fluid communication with an outlet of the engine(s), the turbine section including at least one turbine compounded with the engine shaft, and a compressor having an inlet in fluid communication with an environment of the aircraft and an outlet in fluid communication with a bleed duct for providing bleed air to the aircraft, the compressor having a compressor rotor connected to a compressor shaft, the compressor shaft drivingly engaged to the engine shaft. The driving engagement between the compressor shaft and the engine shaft is configurable to provide at least two alternate speed ratios between the compressor shaft and the engine shaft.

Abstract: An engine assembly for an aircraft, including an internal combustion engine having a liquid coolant system in fluid communication with a heat exchanger, an exhaust duct in fluid communication with air passages of the heat exchanger, a fan in fluid communication with the exhaust duct for driving a cooling air flow through the air passages of the heat exchanger and into the exhaust duct, and an intermediate duct in fluid communication with an exhaust of the engine and having an outlet positioned within the exhaust duct downstream of the fan and upstream of the outlet of the exhaust duct. The outlet of the intermediate duct is spaced inwardly from a peripheral wall of the exhaust duct. The engine assembly may be configured as an auxiliary power unit. A method of discharging air and exhaust gases in an auxiliary power unit having an internal combustion engine is also discussed.

Abstract: A control system for a hybrid electric powerplant of an aircraft can include a master controller configured to receive one or more power settings and to output a heat engine setting and an electric motor setting and a heat engine controller operatively connected to the master controller. The heat engine controller can be configured to receive the heat engine setting and to control a heat engine system as a function of the heat engine setting to control torque output by a heat engine. The system can include an electric motor controller operatively connected to the master controller. The electric motor controller configured to receive the electric motor engine setting and to control an electric motor system as a function of the electric motor setting to control torque output by an electric motor.