A method of controlling a propeller assembly, having a blade, piston end cap, and piston, with a pitch control unit, having a transfer bearing and a blade angle unit, the method comprising: axially moving a transfer tube relative to and circumscribing the transfer bearing, sensing an axial movement of the transfer tube with the blade angle unit.

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.

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.

A pitch control assembly for adjusting the pitch of a propeller blade, including a pitch control unit comprising a housing, with a plurality of control valves and corresponding hydraulic lines located within the housing, a blade angle unit, a transfer bearing mounted to the housing and having a plurality of hydraulic lines fluidly coupled to the hydraulic lines of the pitch control unit, a transfer tube axially receiving and axially moveable relative to at least a portion of the transfer bearing, a magnetic core sleeve carried by the transfer tube and located within the blade angle unit.

Herein provided are sensing systems, methods, sensors, and methods of manufacturing a sensor for a rotating element in an engine. A magnetic core having first and second ends is positioned with the first end proximate the rotating element. A permanent magnet is positioned proximate the second end of the magnetic core and is configured for subjecting the magnetic core and the rotating element to a magnetic field. A bifilar winding comprising a first wire and a second wire electrically insulated from one another is wrapped around at least a portion of the magnetic core, the bifilar winding configured to generate a first signal in the first wire and a second signal in the second wire in response to rotation of the rotating element relative to the sensor.

A calibration system for aircraft control surface actuation includes an inclinometer coupleable to an aircraft control surface. The inclinometer is configured to provide measurement data of an inclination value corresponding to an angle at which the surface is deflected. The system includes an adapter with a wireless transmitter module and an interface connector connected to the inclinometer. The adapter is configured to receive and wirelessly transmit the measurement data. The system includes a wireless receiver device and a computing device connected thereto to receive the measurement data. The computing device is configured to determine if the inclination value differs by more than a predetermined amount from a directed deflection angle for the surface. The computing device is also configured to communicate an adjustment amount to a controller configured to direct deflection of the surface, based on the difference between the measured inclination value and the directed deflection angle.

The invention relates to a control apparatus for a hydraulic variable-pitch propeller (12) of an aircraft, land vehicle or water vehicle, comprising: a hydraulic oil feed line (24); a control line (16) which can be connected to the variable-pitch propeller (12); a pressure generating device (73) which is connected to the hydraulic oil feed line (24) and provides hydraulic oil with a basic pressure; a servo valve (78) which is arranged downstream of the pressure generating device (73), the input pressure to which servo valve is the basic pressure and the output pressure from which servo valve during normal operation defines a control pressure in the control line (16) and which servo valve is connected to a controller (28) which delivers a control signal for changing the control pressure; and pressure reducing means which are arranged downstream of the servo valve (78) and upstream of the control line (16), which are mechanically actuated and which, in the event of a failure of the servo valve (78), change the control pressure in the control line (16).

Systems and methods of operating a tiltrotor aircraft include providing a control system that includes sensors and/or gauges that provide feedback regarding hub shear forces in rotor systems of the aircraft that produce aeroelastic instability known as whirl flutter. Feedback from the sensors and/or gauges is communicated to a flight control subsystem that includes an algorithm that provides a cascading set of responses to control whirl flutter and a failsafe that adjusts operational characteristics of the aircraft in response to the continuation or excitation of the whirl flutter.

A system and method for measuring, or otherwise determining pitch length adjustments to a pitch link coupled to a rotor blade in a rotorcraft includes vertical track adjustment indicators machined onto an exterior of the tube of the pitch link and a vertical reference indicator machined onto an exterior of the upper or the lower rod of the pitch link. A metric of a pitch length adjustment can be determined by tracking or counting how many track adjustment indicators pass the reference indicator while the tube of the pitch link is being turned in either direction for increasing or decreasing the pitch length. The track adjustment indicators can be relied upon to track one or a series of adjustments for tracking a rotor blade installed in a rotor assembly.

A system and method for measuring, or otherwise determining pitch length adjustments to a pitch link coupled to a rotor blade in a rotorcraft includes vertical track adjustment indicators machined onto an exterior of the tube of the pitch link and a vertical reference indicator machined onto an exterior of the upper or the lower rod of the pitch link. A metric of a pitch length adjustment can be determined by tracking or counting how many track adjustment indicators pass the reference indicator while the tube of the pitch link is being turned in either direction for increasing or decreasing the pitch length. The track adjustment indicators can be relied upon to track one or a series of adjustments for tracking a rotor blade installed in a rotor assembly.