How is "airspeed" defined in aviation?

Airspeed is defined as the speed of an aircraft relative to the surrounding air. This measurement is crucial for pilots as it affects the aircraft's performance, including lift generation and stall speed. Knowing the airspeed allows pilots to maintain control of the aircraft in various phases of flight, such as takeoff, cruise, and landing.

The concept of airspeed is important because it is different from groundspeed, which measures the speed of the aircraft relative to the ground. Factors like wind can affect groundspeed but have no effect on airspeed. The maximum speed an aircraft can achieve and the average speed during a flight are not terms that accurately describe airspeed since they focus on different criteria. Understanding airspeed helps pilots gauge their aircraft's aerodynamic performance, thereby enhancing safety and efficiency in flight operations.