What is the source of impact pressure that affects airspeed readout?

The source of impact pressure that affects airspeed readout is the pitot tube. This device is specifically designed to measure the dynamic pressure of the air, which is essential for determining the speed of the aircraft relative to the surrounding airflow. The pitot tube captures air as the aircraft moves, and the pressure that builds up inside it reflects the force of the air impacting the tube’s opening. This impact pressure is then used in calculations to provide the pilot with accurate airspeed information.

Other devices mentioned do not directly measure impact pressure for airspeed. Static air vents contribute to measurements of altitude and vertical speed by measuring the ambient air pressure, but they do not account for the impact pressure needed for airspeed assessments. The altimeter solely measures atmospheric pressure to determine altitude, while the attitude indicator provides information regarding the orientation of the aircraft but is not involved in speed measurement. Therefore, the pitot tube is the correct answer as it is the only device specifically designed for this purpose.