What does the pitot tube primarily measure?

The pitot tube is a critical instrument used in aviation to measure the dynamic pressure of the air flowing around the aircraft. Specifically, it measures the total pressure, which is the sum of static pressure and dynamic pressure. When the airflow strikes the pitot tube, the pressure created by the airflow (dynamic pressure) is added to the static pressure inside the tube, resulting in this total pressure measurement.

By capturing this combined pressure, the pitot tube allows pilots and systems to calculate airspeed. The total pressure reading is essential for determining the aircraft's performance, as it is directly related to the kinetic energy of the air moving over the aircraft. It’s also worth noting that instruments such as airspeed indicators derive their readings from the total pressure measurements obtained by the pitot tube.

As for the other options, static pressure refers solely to the pressure exerted by the weight of the air in the surrounding environment, while dynamic pressure relates to the kinetic energy of the airflow. True airspeed requires adjustments to account for temperature and pressure variations but is not a direct measurement taken by the pitot tube itself.

Therefore, measuring total pressure is the primary function of the pitot tube, which plays a crucial role in flight dynamics and performance monitoring.