An electrical power system architecture and method for allocating power includes a power distribution bus configured to receive power generated by a first engine having a first generator and a second generator, a first set of electrical buses connected with the power distribution bus and associated with the first engine, and a second set of electrical buses configured to selectively connect with the power distribution bus.

An aircraft propulsion system is disclosed and includes a first gas turbine engine including a first input shaft driving a first gear system, a first fan driven by the first gear system, a first generator supported on the first input shaft and a fan drive electric motor providing a drive input to the first fan, a second gas turbine engine including a second input shaft driving a second gear system, a second fan driven by the second gear system, a second generator supported on the second input shaft and a second fan drive electric motor providing a drive input to the second fan and a controller controlling power output from each of the first and second generators and directing the power output between each of the first and second fan drive electric motors.

Methods for monitoring engine health of an aircraft having a first engine and a second engine are provided. In one example, the method includes obtaining a first turbine gas temperature of the first engine and a second engine turbine gas temperature of the second engine from a first flight. The first turbine gas temperature and the second turbine gas temperature are related to each other to define a first value. The first value is compared to a data set for monitoring the engine health.

An aspect includes a method for motoring control for multiple engines of an aircraft is provided. A controller can determine a motoring time of a first engine starting system to cool a first engine. The controller can compare the motoring time of the first engine starting system with a motoring time of one or more other engine starting systems of one or more other engines of the aircraft. The motoring time of the first engine starting system can be controlled relative to a tolerance of the motoring time of the one or more other engine starting systems by adjusting the motoring time of the first engine starting system relative to the one or more other engine starting systems in a motoring sequence based on comparing the motoring time of the first engine starting system with the motoring time of the one or more other engine starting systems.

A gas turbine engine fuel additive control system includes a sensor positioned to sense an operational parameter of a gas turbine engine that includes a compressor section, a combustion section, and a turbine section. The system also includes a control valve positioned to supply a fuel additive to a fuel line. The fuel line contains fuel for supply to the combustion section of the gas turbine engine to which the fuel additive is selectively added by injection into the fuel line. The system also includes a controller configured to monitor the operational parameter in real time during operation of the gas turbine engine and adjust the control valve to dynamically modulate an amount of the fuel additive being supplied in the fuel in accordance with operation of the gas turbine engine.

Systems and Methods are described for testing engine performance in-flight in an aircraft having a first engine and a second engine. The method comprises operating the first engine at a first power level in an output speed governing mode, operating the second engine at a second power level greater than the first power level in a core speed governing mode concurrently with the first engine operating at the first power level in the output speed governing mode, and performing an engine performance test on the second engine while the second engine is at the second power level in the core speed governing mode.

A system and method of reducing engine induced aircraft cabin resonance includes sensing the core engine speed of a first turbofan gas turbine engine, and sensing the core engine speed of a second turbofan gas turbine engine. In a control system, the core engine speed of the first turbofan gas turbine engine and the core engine speed of the second turbofan gas turbine engine are processed to determine a core engine speed difference between the first and second turbofan gas turbine engines. The core engine speed difference is processed to supply a variable inlet guide vane (VIGV) offset value. The VIGV offset value is applied to a VIGV reference command associated with one of the first or second turbofan gas turbine engine to thereby cause the VIGVs of one of the first or second turbofan gas turbine engine to move to a more closed position.

Aircraft autothrottle system, having a motor to impart rotational movement to a shaft extending from the motor. An actuator is connected to the shaft and to an attachment end of a throttle lever having a control end, opposite the attachment end. The actuator has bearings to apply thrust to a longitudinal surface of the shaft such that the actuator is translated longitudinally along the shaft surface in response to motor-imparted rotation of the shaft. The shaft surface being smoothly continuous and longitudinally unbroken along its elongation to allow the actuator to longitudinally slip along the shaft irrespective of any shaft rotation by the motor when the thrust force exceeds a linear force manually applied at the throttle lever. An electronic controller for the motor to move the throttle lever so the motor moves the actuator assembly along the shaft based on an engine parameter monitored by the controller.

An aircraft gas turbine engine system comprises first and second gas turbine engines connected by an inter-engine gas path. The first gas turbine engine has a first spool with a first compressor section, and a second spool with a second compressor section downstream of and rotationally independent from the first compressor section. The second gas turbine engine is configured to provide power to at least one of the first and second spools of the first gas turbine engine. The inter-engine gas path is disposed to receive gas flow bled from a bleed location in the first gas turbine engine downstream of the first compressor section, and to supply this gas flow to an inlet of the second gas turbine engine.

A control method/system for a hybrid-electric aircraft propulsion system includes a generator, a propulsor, a controller and an electric storage unit. The generator including a gas turbine with blades separated from a casing by a clearance and driving an electric generator. An electric motor drives the propulsor. The controller controls the turbine and supply of electric power between the motor, the storage unit and the generator in response to a thrust demand and cooperates with a clearance controller: receives a command for a change in thrust demand; determines an operational profile that minimizes a function comprising a measure of fuel supplied to the turbine, transferring electric power from/to the storage unit, a difference between measures of current and demanded thrust and clearance over a time period; and operates the motor, turbine and storage unit according to the operational profile over the time period.