Abstract: A blade angle feedback ring assembly for an aircraft propeller rotatable about a longitudinal axis and having an adjustable blade angle is provided. A feedback ring is coupled to the propeller to rotate therewith and to move along a longitudinal axis with adjustment of the blade angle. A plurality of rods are coupled to the feedback ring and extending along a direction substantially parallel to the longitudinal axis, the rods configured to support the feedback ring for longitudinal sliding movement along the longitudinal axis with adjustment of the blade angle. At least one shielding element is provided between the feedback ring and the propeller for shielding the feedback ring from electromagnetism.

Abstract: Systems and methods for controlling a crossing threshold used in determining a rotational speed of a propeller of an aircraft engine. An initial value for the crossing threshold is set. A sensor signal is received that comprises a first series of pulses indicative of passage of position markers about a circumference of a propeller shaft. A detection signal is generated that comprises a second series of pulses indicative of within the first series of pulses that have a zero-crossing transition and a magnitude that exceeds the crossing threshold. The rotational speed of the propeller is determined from the detection signal. The crossing threshold is adjusted as a function of the rotational speed.

Abstract: Herein provided are systems and methods for synchrophasing multi-engine aircraft. A phonic wheel is coupled to a first propeller of a first engine of the aircraft. A sensor is disposed and configured for producing a signal in response to passage of first and second position markers on the phonic wheel. A control system is communicatively coupled to the sensor for obtaining the signal, and configured for: determining an expected delay between two subsequent signal pulses of the signal; identifying from within the plurality of signal pulses a particular pulse associated with the second position marker; determining, based on a particular time at which the particular pulse associated with the second position marker was produced, that a rotational position of the first propeller corresponds to a reference position at the particular time; and performing at least one synchrophasing operation for the aircraft based on the rotational position of the first propeller.

Abstract: Herein provided is a phonic wheel for use in a gas turbine engine and associated systems and methods. The phonic wheel comprises a circular disk having first and second opposing faces. The circular disk defines a root surface that extends between and circumscribes the first and second faces. A first plurality of projections extend from the root surface and are oriented substantially parallel to an axis of rotation of the disk. The first plurality of projections are circumferentially spaced substantially equally from one another and each have a first physical configuration. At least one second projection extends from the root surface and is positioned between two adjacent first projections, the at least one second projection having a second physical configuration different from the first physical configuration.

Abstract: An aircraft propeller control system for an aircraft propeller with adjustable blade angle has a blade angle feedback ring and a sensor, one of which is mounted for rotation with the propeller. The blade angle feedback ring moves longitudinally along with adjustment of the blade angle and has position markers circumferentially spaced apart at distances that vary along a longitudinal axis. The sensor is positioned adjacent the feedback ring for producing signals indicative of passage of the position markers. Intervals between signals are indicative of circumferential distances between position markers. A controller measures longitudinal position of the feedback ring based on the intervals and is configured to produce a warning signal if the longitudinal position is outside a first threshold range.

Abstract: A system and method for blade angle position feedback. The system comprises an feedback device and a sensor mounted adjacent the feedback device and configured for detecting a passage of position markers on the feedback device during propeller rotation. The position markers are spaced apart from one another around the circumference of the feedback device and are oriented at an angle to one another and to a longitudinal axis. The feedback device and sensor are configured for relative axial displacement. A detection unit is connected to the sensor for receiving the sensor signal therefrom, determining on the basis of the sensor signal a time interval elapsed between the passage of successive position markers, and computing from the time interval blade angle position.

Abstract: An aircraft propeller control system for an aircraft propeller with adjustable blade angle has a blade angle feedback ring and a sensor, one of which is mounted for rotation with the propeller. The blade angle feedback ring moves longitudinally along with adjustment of the blade angle and has position markers circumferentially spaced apart at distances that vary along a longitudinal axis. The sensor is positioned adjacent the feedback ring for producing signals indicative of passage of the position markers. Intervals between signals are indicative of circumferential distances between position markers. A controller measures longitudinal position of the feedback ring based on the intervals and is configured to produce a warning signal if the longitudinal position is outside a first threshold range.

Abstract: A system and method for blade angle position feedback. The system comprises an feedback device and a sensor mounted adjacent the feedback device and configured for detecting a passage of position markers on the feedback device during propeller rotation. The position markers are spaced apart from one another around the circumference of the feedback device and are oriented at an angle to one another and to a longitudinal axis. The feedback device and sensor are configured for relative axial displacement. A detection unit is connected to the sensor for receiving the sensor signal therefrom, determining on the basis of the sensor signal a time interval elapsed between the passage of successive position markers, and computing from the time interval blade angle position.