Abstract: A multi-rotor electric machine having a stator, a first rotor magnetically coupled to the stator and a second rotor magnetically coupled to the stator is disclosed. A method of operating the electric machine comprises driving a gear via a first face of the gear using the first rotor and driving the gear via a second face of the gear using the second rotor.

Abstract: The magnetic chip detector system can have a first conductor member and a second conductor member both exposed to a liquid flow path and separated from one another by gap, each one of the conductor members having a magnetic field oriented into the liquid flow path, at least a first one of the magnetic fields being actively modifiable; an electrical energy source configured to induce a current circulation across the gap; and a meter configured to measure a response of the gap to the induced current circulation.

Abstract: A gas turbine engine can have a magnetic chip detector system with a first conductor member and a second conductor member both exposed to a lubricant flow path of the gas turbine engine, at least a first one of the conductor members including an electromagnet including a coil wrapped around a ferromagnetic core. As part of an engine shutdown procedure, an intrinsic magnetic field strength within the ferromagnetic core can be increased by circulating electrical current in the coil, and the electrical current circulation can then be interrupted for the magnetic field to remain active during engine shutdown.

Abstract: There is described a shaft shear event detection method. The method comprises storing in memory a shaft oscillation signature determined as a function of known characteristics of the shaft and associated with a shaft shear event; monitoring a rotational speed of the shaft; detecting from the rotational speed an oscillation wave superimposed on the rotational speed by detecting a first period below a lower threshold and a second period above an upper threshold, and detecting a rate of occurrence of the first period and the second period, the oscillation wave having a wave modulation frequency corresponding to the rate of occurrence and a wave modulation amplitude; comparing the oscillation signature to the oscillation wave; and detecting the shaft shear event when the oscillation wave corresponds to the oscillation signature.

Abstract: A multi-rotor electric machine having a stator, a first rotor magnetically coupled to the stator and a second rotor magnetically coupled to the stator is disclosed. A method of operating the electric machine comprises driving a gear via a first face of the gear using the first rotor and driving the gear via a second face of the gear using the second rotor.

Abstract: Methods and systems for measuring an axial position of a rotating component of an engine are described herein. The method comprises obtaining a signal from a sensor coupled to the rotating component, the rotating component having a plurality of position markers distributed about a surface thereof, the position markers having an axially varying characteristic configured to cause a change in a varying parameter of the signal as a function of the axial position of the rotating component. Based on the signal, the method comprises determining a rotational speed of the rotating component from the signal, determining the varying parameter of the signal, and finding the axial position of the rotating component based on a known relationship between the axial position, the rotational speed, and the varying parameter of the signal.

Abstract: Methods and Systems for health-monitoring of a multi-channel pressure transducer of a gas turbine engine are described. The method comprises monitoring a deviation between a first channel and a second channel of a multi-channel pressure transducer over time, determining a rate of change of the deviation, extrapolating a trend over time based on the rate of change of the deviation to predict when the deviation will reach a threshold, and triggering a maintenance action for the pressure transducer based on the trend.

Abstract: Systems and methods for monitoring a pressure transducer are described. The method comprises sampling an output signal of a pressure transducer to obtain a plurality of pressure measurements as recorded by the pressure transducer, comparing the pressure measurements to a first pressure exposure limit associated with the pressure transducer, and recording data related to exposure of the pressure transducer to the first pressure exposure limit.

Abstract: Methods and systems of operating a gas turbine engine in a low-power condition are provided. In one embodiment, the method includes supplying fuel to a combustor by supplying fuel to a first fuel manifolds and a second fuel manifold of the gas turbine engine. The method also includes, while supplying fuel to the combustor by supplying fuel to the first fuel manifold: stopping supplying fuel to the second fuel manifold; and using a pump to drive gas into the second fuel manifold to flush fuel in the second fuel manifold into the combustor and hinder coking in the second fuel manifold and associated fuel nozzles.

Abstract: A system and method for measuring a speed of an engine are provided. The engine has a positive displacement pump drivingly connected to a rotor shaft thereof, the pump having an inlet for receiving a fluid supply and an outlet for outputting pressurized fluid. A sensor signal is received from a pressure sensing device provided at an inlet of the pump, the sensor signal comprising a series of periodic oscillations. A frequency of the oscillations is determined, the frequency proportional to a rotational speed of the rotor shaft. The speed of the engine is then determined from the frequency of the oscillations and the speed of the engine as determined is output for controlling operation of the engine.

Abstract: Methods and systems for detecting an uncommanded or uncontrollable high thrust (UHT) event in an aircraft are described. The method comprises detecting an abnormal engine response as a function of a fuel flow error, the fuel flow error indicative of a presence of excess thrust; in response to detecting the fuel flow error, detecting a UHT event based on the excess thrust and as a function of a threshold; and accommodating the UHT event when the UHT event is detected.

Abstract: A multi-rotor electric machine having a stator, a first rotor magnetically coupled to the stator and a second rotor magnetically coupled to the stator is disclosed. A method of operating the electric machine comprises driving a gear via a first face of the gear using the first rotor and driving the gear via a second face of the gear using the second rotor.

Abstract: Herein provided are methods and systems for detecting an uncommanded or uncontrollable high thrust (UHT) event in an aircraft, comprising arming a UHT function, detecting a fuel flow error when an actual fuel flow minus a commanded fuel flow exceeds a first threshold, the fuel flow error indicative of a presence of excess thrust, detecting a UHT event based on excess thrust and as a function of a second threshold, upon detection of the fuel flow error, and accommodating the UHT event.

Abstract: A multi-phase cable, the cable including a plurality of conductors for conducting currents of two or more different phases, each phase being associated with one or more conductors and each conductor being associated with one respective phase. Each conductor has a cross-section with at least one dimension that is sized to decrease a skin effect of the conductor at a maximum or nominal operation frequency of the conductor. The conductors are arranged to permit free air cooling of the cable on at least two sides of each conductor, and such that each conductor of a given phase has, as immediate neighbors, only conductors of one or more different phases.

Abstract: Herein provided are methods and systems for detecting an uncommanded or uncontrollable high thrust (UHT) event in an aircraft, comprising arming a UHT function, comparing an engine fan speed to a reference target and detecting a first condition when a first threshold is exceeded, comparing a rate of change of a high pressure rotor speed to a reference deceleration schedule and detecting a second condition when a second threshold is exceeded, detecting a UHT event based on excess thrust when the first condition and the second condition are detected, and accommodating the UHT event.

Abstract: There is described a shaft shear event detection method. The method comprises storing in memory a shaft oscillation signature determined as a function of known characteristics of the shaft and associated with a shaft shear event; monitoring a rotational speed of the shaft; detecting from the rotational speed an oscillation wave superimposed on the rotational speed by detecting a first period below a lower threshold and a second period above an upper threshold, and detecting a rate of occurrence of the first period and the second period, the oscillation wave having a wave modulation frequency corresponding to the rate of occurrence and a wave modulation amplitude; comparing the oscillation signature to the oscillation wave; and detecting the shaft shear event when the oscillation wave corresponds to the oscillation signature.

Abstract: There is described a shaft shear event detection method. The method comprises obtaining a demodulated waveform of a shaft oscillation wave superimposed on a shaft rotational speed signal, comparing the amplitude to an amplitude threshold, detecting oscillation when the amplitude threshold is exceeded for a plurality of samples, and detecting a shaft shear when oscillation continues for a predetermined time limit.

Abstract: There is described a shaft shear event detection method. The method comprises storing in memory a shaft oscillation signature determined as a function of known characteristics of the shaft and associated with a shaft shear event; monitoring a rotational speed of the shaft; detecting from the rotational speed an oscillation wave superimposed on the rotational speed, the oscillation wave having a wave modulation frequency and a wave modulation amplitude; comparing the oscillation signature to the oscillation wave; and detecting the shaft shear event when the oscillation wave corresponds to the oscillation signature.

Abstract: Herein provided are methods and systems for detecting an uncommanded or uncontrollable high thrust (UHT) event in an aircraft, comprising arming a UHT function, comparing an engine fan speed to a reference target and detecting a first condition when a first threshold is exceeded, comparing a rate of change of a high pressure rotor speed to a reference deceleration schedule and detecting a second condition when a second threshold is exceeded, detecting a UHT event based on excess thrust when the first condition and the second condition are detected, and accommodating the UHT event.

Abstract: Herein provided are methods and systems for detecting an uncommanded or uncontrollable high thrust (UHT) event in an aircraft, comprising arming a UHT function, detecting a fuel flow error when an actual fuel flow minus a commanded fuel flow exceeds a first threshold, the fuel flow error indicative of a presence of excess thrust, detecting a UHT event based on excess thrust and as a function of a second threshold, upon detection of the fuel flow error, and accommodating the UHT event.