The aircraft includes a rotor. The rotor includes a plurality of rotor blades. The aircraft further includes a non-rotating aircraft component. A proximity sensor is disposed with at least one of the non-rotating aircraft component and the rotor blades. A flight control computer is electrically coupled to the proximity sensor.

Blade feedback systems and methods for determining a blade angle position and rotational speed of a plurality of propeller blades of a variable pitch propeller assembly are provided. Exemplary blade feedback system includes features for determining an axial position of a beta tube. Based at least in part on the axial position of the beta tube, the blade angle of the plurality of propeller blades can be determined. Exemplary blade feedback system can also include features for determining the rotational speed of the beta tube such that the rotational speed of the propeller blades can be determined.

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.

A blade angle feedback ring assembly for an aircraft engine propeller having adjustable angle blades is provided. The feedback ring assembly comprises a feedback ring coupled to rotate with the propeller, the engine configured such that a first electrically-conductive path is defined between the propeller and the engine via the feedback ring, and an electric current conduction element provided between the propeller and the engine to define a second electrically-conductive path between the propeller and the engine in parallel to the first path, the second electrically-conductive path configured with a lower electrical resistance to conduction between the propeller and the engine than the first electrically-conductive path.

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.

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.

The aircraft includes a rotor. The rotor includes a plurality of rotor blades. The aircraft further includes a non-rotating aircraft component. A proximity sensor is disposed with at least one of the non-rotating aircraft component and the rotor blades. A flight control computer is electrically coupled to the proximity sensor.

A system and method for determining a position of a feedback ring of a propeller of an aircraft engine are provided. The feedback ring is coupled to the propeller to rotate with the propeller and to be displaced along a longitudinal axis with adjustment of a blade angle. An engagement member is configured to engage the feedback ring and to be displaced along a longitudinal direction substantially parallel to the longitudinal axis with displacement of the feedback ring. A sensor comprises a first member coupled to the engine and a second member coupled to the engagement member. The second member is moveable relative to the first member along the longitudinal direction as the engagement member is displaced. The sensor generates a signal indicative of a longitudinal position of the second member relative to the first member. A controller determines an axial position of the feedback ring from the sensor signal.

A sensor signal produced by a sensor as a feedback device rotates with a propeller about an axis and moves along the axis with adjustment of a blade angle of the propeller is received, the sensor signal indicative of a rotational speed and of the blade angle of the propeller. From the sensor signal, it is determined whether the rotational speed is within a predetermined range of a reference speed and an expected change in the blade angle has occurred in response to a command to adjust the blade angle to maintain the rotational speed at the reference speed. In response to determining that the rotational speed is within the predetermined range of the reference speed and the expected change in the blade angle has failed to occur in response to the command, inoperable movement of the feedback device along the axis is determined and an alert is output.

The invention relates to a method for controlling a pitch angle of the vanes or blades of a propellant body of a turbine engine, comprising generating a pitch command (i.sub.final) according to a rotational speed of the propeller (XN.sub.mes) and a speed setpoint (XN.sub.cons), the method comprises a nominal regulating chain (13), wherein the pitch command is further generated according to a value of a pitch angle (mes) of the vanes or blades of the propellant body, and an off-nominal regulating chain (16), wherein the pitch command is generated independently of a value of a pitch angle of the vanes or blades of the propellant body.