Blade Angle Measurement Method for Automatic Pitch Propeller in Flight Testing

Automatic pitch propeller is a common power plant used in medium and large transport aircrafts. The blade angle of automatic variable pitch propellers can change in real time with the incoming flow conditions and the engine power, so as to get high propulsion efficiency in the full flight envelope. The propeller blade angle is a key parameter for evaluating the working characteristics and performance of the propeller. The high speed and strong vibration environment of the propeller blade brings great difficulties to the measurement of the blade angle. In this paper, the structure of propeller blade angle measurement system was proposed based on the principle of potentiometer and radio frequency, the scheme of blade angle measurement system was designed according to the specific structure of the propeller. The adaptability of the blade angle measurement system to the flight environment is verified by finite element analysis, over-speed rotation test and random vibration test. The blade angle measurement has been successfully conducted in flight condition, which provides an important support for the evaluation of propeller performance and operation characteristics.