Abstract: A method of monitoring the health of an aircraft propeller whilst the propeller is in operation, the propeller having a plurality of blades extending radially outwardly from hub arms of a propeller hub, which in turn extend radially outwardly from a central axis extending through the propeller and a propeller drive shaft, is provided. The method comprises obtaining measurements representative of the strain in each of at least some of the hub arms using strain sensors, each of the strain sensors being provided on a respective hub arm. A corresponding propeller health monitoring system, an aircraft propeller comprising the system and an aircraft comprising the propeller are also provided.

Abstract: A propeller health monitoring system for an aircraft includes an aircraft having one or more propellers that includes light in or on them. The system includes one or more receptors mounted to a fuselage or a nacelle of the aircraft, each receptor having a sensor surface which is able to detect a position for each light beam crossing over the sensor surface as the propeller rotates, such that the receptor generates a signal that is indicative of the position as a measure of blade tip trajectory for each passing propeller blade The system also includes a processing unit which analyses the signals from the receptor to determine health of the propeller blades of the one or more propellers based on where the beams of light from the propeller blades have crossed over the sensor surface.

Abstract: A system for monitoring propeller health includes a processing unit having a processor which is programmed to apply a plurality of algorithms to inputted aircraft parameter data. The system also includes a plurality of data inputs for inputting aircraft parameter data into the algorithms, wherein the processor is configured to apply the physics based algorithms to the aircraft parameter data to determine at least the fatigue life consumption of one or more critical components of a propeller. In addition, the system includes an output device which is able to output an indication of the determined fatigue life consumption to an observer.

Abstract: A system for monitoring propeller health includes a processing unit having a processor which is programmed to apply a plurality of algorithms to inputted aircraft parameter data. The system also includes a plurality of data inputs for inputting aircraft parameter data into the algorithms, wherein the processor is configured to apply the physics based algorithms to the aircraft parameter data to determine at least the fatigue life consumption of one or more critical components of a propeller. In addition, the system includes an output device which is able to output an indication of the determined fatigue life consumption to an observer.

Abstract: A propeller health monitoring system for an aircraft includes an aircraft having one or more propellers that includes light in or on them. The system includes one or more receptors mounted to a fuselage or a nacelle of the aircraft, each receptor having a sensor surface which is able to detect a position for each light beam crossing over the sensor surface as the propeller rotates, such that the receptor generates a signal that is indicative of the position as a measure of blade tip trajectory for each passing propeller blade The system also includes a processing unit which analyses the signals from the receptor to determine health of the propeller blades of the one or more propellers based on where the beams of light from the propeller blades have crossed over the sensor surface.

Abstract: A blade for a propeller including a blade composite structure includes a Fiber Bragg Grating (FBG) or an Extrinsic Fabry-Perot Interferometric (EFPI) sensor embedded in the blade composite structure. The sensor is configured to receive a signal from a controller operatively connected to the FBG or EFPI sensor, and transmit a signal, responsive to the received signal, to a processor operatively connected to the sensor. The signal response is indicative of a stress measurement indicating a structural characteristic of the blade composite structure. The signal response provides information to determine, based on the signal response, whether the structural characteristic of the blade composite structure is within a predetermined limit indicative of structural integrity of the blade composite structure.

Abstract: A method for monitoring the health of propellers in an aircraft is provided. The method includes receiving pressure waves generated by at least one rotating propeller and analysing data corresponding to the received pressure waves to detect tonal noise which is within a selected frequency range. If tonal noise at harmonics of the propeller rotational frequency within the selected frequency range is detected within the selected frequency range, it is established that the health of at least one propeller may be impaired and an alert is created for inspection and maintenance to take place.

Abstract: A method of monitoring the health of an aircraft propeller whilst the propeller is in operation, the propeller having a plurality of blades extending radially outwardly from a central axis extending through the propeller and a propeller drive shaft, is provided. The method includes obtaining measurements representative of strain in the propeller drive shaft using multiple primary strain sensors, each primary strain sensor providing respective measurements representative of strain. The primary strain sensors are located around a circumference of the drive shaft of the propeller, and each strain sensor is located such that it crosses a plane defined by the radial direction of a blade and the central axis, the plane being bounded by the central axis. A corresponding propeller health monitoring system, an aircraft propeller comprising the system and an aircraft comprising the propeller are also provided.

Abstract: A method for monitoring the health of propellers in an aircraft is provided. The method includes receiving a first propeller pitch angle of a first propeller of an aircraft; calculating a first residual pitch angle which is the difference between the first propeller pitch angle and a second propeller pitch angle; and comparing the first residual pitch angle to at least one threshold. The at least one threshold may include upper and lower thresholds. It is established that the health of the propeller may be impaired if the residual pitch angle is outside the at least one threshold, for example it exceeds the upper threshold or is below the lower threshold. If it is established that the health of the propeller may be impaired, an alert is made for inspection and maintenance to take place.

Abstract: A blade for a propeller including a blade composite structure includes a Fiber Bragg Grating (FBG) or an Extrinsic Fabry-Perot Interferometric (EFPI) sensor embedded in the blade composite structure. The sensor is configured to receive a signal from a controller operatively connected to the FBG or EFPI sensor, and transmit a signal, responsive to the received signal, to a processor operatively connected to the sensor. The signal response is indicative of a stress measurement indicating a structural characteristic of the blade composite structure. The signal response provides information to determine, based on the signal response, whether the structural characteristic of the blade composite structure is within a predetermined limit indicative of structural integrity of the blade composite structure.

Abstract: A method of monitoring the health of an aircraft propeller whilst the propeller is in operation, the propeller having a plurality of blades extending radially outwardly from a central axis extending through the propeller and a propeller drive shaft, is provided. The method comprises: obtaining measurements representative of strain in the propeller drive shaft using multiple primary strain sensors, each primary strain sensor providing respective measurements representative of strain; wherein the primary strain sensors are located around a circumference of the drive shaft of the propeller; and wherein each strain sensor is located such that it crosses a plane defined by the radial direction of a blade and the central axis, the plane being bounded by the central axis. A corresponding propeller health monitoring system, an aircraft propeller comprising the system and an aircraft comprising the propeller are also provided.

Abstract: A method of monitoring the health of an aircraft propeller whilst the propeller is in operation, the propeller having a plurality of blades extending radially outwardly from hub arms of a propeller hub, which in turn extend radially outwardly from a central axis extending through the propeller and a propeller drive shaft, is provided. The method comprises obtaining measurements representative of the strain in each of at least some of the hub arms using strain sensors, each of the strain sensors being provided on a respective hub arm. A corresponding propeller health monitoring system, an aircraft propeller comprising the system and an aircraft comprising the propeller are also provided.

Abstract: A method for monitoring the health of propellers in an aircraft is provided. The method includes receiving pressure waves generated by at least one rotating propeller and analysing data corresponding to the received pressure waves to detect tonal noise which is within a selected frequency range. If tonal noise at harmonics of the propeller rotational frequency within the selected frequency range is detected within the selected frequency range, it is established that the health of at least one propeller may be impaired and an alert is created for inspection and maintenance to take place.

Abstract: A method for monitoring the health of propellers in an aircraft is provided. The method includes receiving a first propeller pitch angle of a first propeller of an aircraft; calculating a first residual pitch angle which is the difference between the first propeller pitch angle and a second propeller pitch angle; and comparing the first residual pitch angle to at least one threshold. The at least one threshold may include upper and lower thresholds. It is established that the health of the propeller may be impaired if the residual pitch angle is outside the at least one threshold, for example it exceeds the upper threshold or is below the lower threshold. If it is established that the health of the propeller may be impaired, an alert is made for inspection and maintenance to take place.