What should you do first to verify the accuracy of the airspeed indicator before flight?

To verify the accuracy of the airspeed indicator before flight, ensuring that it reads zero at rest is the essential first step. This process is known as a pre-flight check and involves confirming that the airspeed indicator reflects a reading of zero when the aircraft is motionless.

This step is crucial because it establishes a baseline for the airspeed readings during flight. The airspeed indicator works by measuring the difference between static pressure and dynamic pressure from the pitot tube. If the indicator does not start at zero, it indicates that there might be a malfunction or calibration issue, which can lead to incorrect speed readings during flight. Establishing a zero reading means that any subsequent readings can be deemed accurate from that starting point.

Checking in flight, performing a system reset, or cross-checking with radar are not viable first steps, as they do not address the fundamental need to ensure the airspeed indicator's basic functionality and accuracy before takeoff. Without confirming that the indicator reads zero while the aircraft is at rest, the pilot cannot rely on the airspeed data during flight.