An avionics system and process for detecting pneumatic blockages having an air pressure measurement system including a first sensor positioned in association with the air inlet of an air probe component. The air pressure measurement system having a second sensor positioned in association with the air inlet for detecting air pressure in which the second sensor has a frequency response higher than that of the first sensor. An air data computer is coupled to each of the first and second sensors being configured and operable to calculate a first aircraft movement measurement using detected air pressure from the first sensor and is further operative to determine if the first sensor is faulty or if the air inlet is blocked in dependence upon the frequency content and amplitude of the output from the second sensor.