Methods and systems for testing a sensor of a propeller blade angle position feedback system are described. A sensor signal is received from a sensor at a known position relative to a feedback device, the feedback comprising a ring and at least one pair of position markers spaced from one another around a circumference thereof, the sensor configured for successively detecting passage of the position markers as the feedback device rotates at a known rotational speed and an axial distance between the sensor and the feedback device varies. From the sensor signal a measured position of the sensor relative to the feedback device and a measured rotational speed of the feedback device are determined. The measured position and the measured rotational speed are compared to the known position and the known rotational speed to determine a sensor accuracy.