Which statement about the ASI mechanism is true when facing a blocked pitot tube?

When a Pitot tube is blocked, it prevents the proper measurement of dynamic pressure, which is essential for calculating airspeed. The ASI (Airspeed Indicator) relies on this dynamic pressure to provide a reading. If the Pitot tube becomes blocked, the ASI effectively loses the input needed for accurate speed measurement. Therefore, in a situation where the Pitot tube is entirely obstructed, the ASI would indicate zero airspeed because it reads a static pressure without any real dynamic pressure readings coming from the blocked tube.

This result occurs because the ASI reads the difference between the static pressure and the dynamic pressure generated by the airflow. With a blocked Pitot tube, there would be no dynamic pressure to measure against, leading to an airspeed indication of zero, which aligns with the understanding of how the ASI and Pitot system work together.