An aircraft includes a first propulsion unit, a second propulsion, and a controller configured to increase thrust output in one of the first propulsion unit or the second propulsion unit in response to a detected thrust reduction from the other of the first propulsion unit. Each of the first propulsion unit and the second propulsion unit include a rotor driven by a gas turbine engine with a drive shaft, an output shaft coupled between the drive shaft and the driven rotor and a mechanical coupler for decoupling the output shaft from the drive shaft.

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.

A turbomachine for a vehicle is provided. The turbomachine includes a first rotatable component; a first power source operatively coupled with the first rotatable component; a second power source selectively coupled with the first rotatable component; and a controller having one or more processors and one or more memory devices, the one or more memory devices storing instructions that when executed by the one or more processors cause the one or more processors to perform operations, in performing the operations, the one or more processors are configured to: receive an input indicating an engine shutdown of the turbomachine; and in response to the engine shutdown, cause the second power source to provide power to and rotate the first rotatable component.

A method for controlling a turbomachine comprising including a fan positioned upstream of a gas generator. The turbomachine including an electric motor forming a torque injection device for a high-pressure rotary shaft, in which method a fuel flow setpoint for a combustion chamber and a torque setpoint (Tcons) for the electric motor (ME) are determined. The control method including the steps of determining (El) a hybridisation rate (TH) corresponding to the ratio of the power (Pe) consumed by the electric motor (ME) to the power generated by the high-pressure rotary shaft (P2), determining (E2) a torque threshold (Tseuil) from the hybridisation rate (TH), limiting (E3) the torque setpoint (Tcons) to the torque threshold (Tseuil) if the torque setpoint (Tcons) is higher than the torque threshold (Tseuil).

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 method for operating a hybrid-electric propulsion system of an aircraft, the hybrid-electric propulsion system comprising a gas turbine engine having a compressor and an electric machine coupled to the compressor, the method comprising: sensing data indicative of a pressure within the compressor of the gas turbine engine; determining conditions within the compressor are within a threshold of a stall limit for the compressor based at least in part on the sensed data indicative of the pressure within the compressor of the gas turbine engine; and modifying a torque of the compressor using the electric machine in response to determining the conditions within the compressor are within the threshold of the stall limit for the compressor to reduce a risk of compressor stall.

A method for compensating torsional loads applied to a shaft coupled to a main engine, comprising measuring values indicative of torsional loads applied on the shaft or power demand from the main engine; computing from the values the torsional load over time and a parameter indicative of a cycle; after measuring the group of values, measuring a subsequent value indicative of torsional loads applied on the shaft, and applying a compensating moment or load in a direction determined by whether the subsequent value is greater than or smaller than the value representing the torsional load over time. The direction is a torque direction applied to the shaft by the main engine or the opposite direction.

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.