Systems and methods for starting an engine on an aircraft are provided. One example aspect of the present disclosure is directed to an integrated starter for starting an engine on an aircraft. The integrated starter includes an air turbine starter. The integrated starter includes a starter air valve integrated with the air turbine starter. The integrated starter includes a controller configured to control the starter air valve. The starter air valve can be movable between a first position and at least a second position to regulate the flow of fluid into the air turbine starter. An output torque of the air turbine starter can be dependent at least in part on the flow of fluid into the air turbine starter.

An assembly for an aircraft propulsion system includes a propulsor, an engine, and electrical distribution system, and a controller. The propulsor is configured for rotation about a rotational axis. The engine includes a rotor coupled with the propulsor. The electrical distribution system includes an electric motor. The electric motor is coupled with the propulsor. The electric motor and the rotor are configured to cooperatively control rotation of the propulsor about the rotational axis by applying a total torque to the propulsor. The total torque includes a motor torque of the electric motor and an engine torque of the rotor. The controller is configured to: identify a target rotation speed for the propulsor, identify a deviation of an actual rotation speed of the propulsor from the identified target rotation speed, change a target total torque for the propulsor, control the engine to change an actual engine torque of the rotor to the target total torque, and while controlling the engine to change the actual engine torque of the rotor to the target total torque, identify a torque difference between the actual engine torque and the target total torque and control the electric motor to apply a target motor torque to the propulsor based on the torque difference.

A method and control system for an aircraft using a gas turbine engine is provided. The control system includes a controller that includes a load and engine control modules and communicates control signals to a plant that includes a gas generator and a rotor load, an engine estimation module that receives engine state measurements and effector feedback/command signals from the controller and communicates a power turbine torque estimate, and a load estimation module that receives signals including the power turbine torque estimate, a first power turbine speed value, a first power turbine torque value, a second power turbine speed value, a second power turbine torque value, and a rotor speed value. The load estimation module generates one or more of a power turbine speed estimate, a power turbine torque estimate, and a rotor load estimate based on the received signals.

Systems and methods for determining torque split among engines in a multi-engine system using adaptive engine models are provided. In one embodiment, a method of determining a torque split can include generating a first model specifying torque versus fuel flow for a first engine based at least in part on measured operating points for the first engine; and generating a second model specifying torque versus fuel flow for a second engine based at least in part on measured operating points for the second engine. The method can further include determining a torque split for the first engine and the second engine that reduces total fuel flow for the first engine and the second engine based at least in part on the first model and the second model; and controlling the torque output of the first engine and the second engine based at least in part on the torque split.

A sensor arrangement for a gas powered turbine includes at least one sensor disposed on a power extraction shaft and configured to output a measured power extraction of the power extraction shaft. A controller is in communication with the at least one sensor. The controller includes a memory and a processor. The memory stores instructions for causing the processor to respond to a received measured power extraction of the power extraction shaft by synthesizing an instantaneous engine power output and engine efficiency and adjusting at least one parameter of the engine based on the synthesized engine power output and engine efficiency.

A gas turbine engine includes a fan section having a fan rotatable with a fan shaft, a turbomachinery section having a turbine and a turbomachine shaft rotatable with the turbine, a power gearbox mechanically coupled to the fan shaft and the turbomachine shaft such that the fan shaft is rotatable by the turbomachine shaft across the power gearbox, a grounded structure coupled to and supporting the power gearbox, and a torque monitoring system. The torque monitoring system includes a gearbox sensor. The gearbox sensor is coupled to the grounded structure and the torque monitoring system configured to determine a torque across the power gearbox using the gearbox sensor.

An electricity generation system according to an embodiment of the present invention includes an engine, an electric generator, a detector, and a control device. The engine has a compressor including a rotating shaft. The electric generator is connected to the rotating shaft and generates electricity with rotational force of the rotating shaft. The detector detects shaft torque of the electric generator. The control device controls an operational status of the engine or the electric generator on the basis of the shaft torque.

A propulsion assembly includes a first torque source coupled with a first shaft and a second torque source coupled with a second shaft. A coupler selectively couples the first and second torque sources. When the first and second torque sources are coupled via the coupler, in response to a command to decouple the first torque source, an unloading operation is performed to decrease the torque output provided by the first torque source to a threshold, and when reached, the first shaft is decoupled from the coupler. When the first torque source is coupled with the coupler but the second torque source is not, in response to a command to couple the second torque source, a speed matching operation is performed to increase the speed of the second shaft to match a speed of the first shaft, and when the speeds are matched, the second shaft is coupled to the coupler.

A turboshaft engine is provided and includes a turbine shaft, an output shaft and a combined speed ratio stage and torque measuring system. The combined speed ratio stage and torque measuring system includes a rigid assembly, a sensor system and first and second bearings. The rigid assembly includes a torque tube, a first gear-speed ratio stage to transmit gear-reduced or gear-increased torque from the turbine shaft and to the torque tube and a second gear-speed ratio stage to transmit gear-reduced or gear-increased torque from the torque tube to the output shaft. The sensor system measures twist of the torque tube. The first and second bearings support the rigid assembly.

There is provided a method and system for operating a turboprop engine of an aircraft. When a resulting value for Ng is between at least one upper limit and at least one lower limit, the output power is governed as a function of the target power. When the resulting value for Ng is on or outside of the at least one upper limit and the at least one lower limit, the output power is governed as a function of the maximum Ng and the minimum Ng.