What does true airspeed (TAS) measure?

True airspeed (TAS) measures the actual speed of an aircraft relative to the surrounding air. It represents how fast the aircraft is moving through the atmosphere, taking into account factors such as altitude and temperature. Unlike ground speed, which is affected by wind direction and speed, TAS focuses solely on the aircraft's movement relative to the air mass itself. This measurement is crucial for pilots to understand performance and aircraft handling characteristics, as it is a key factor in determining lift, fuel efficiency, and navigation accuracy. Understanding TAS allows pilots to make informed decisions related to flight operations.