How do you calculate true airspeed (TAS)?

True airspeed (TAS) is the actual speed of an aircraft through the air, and it is important for navigation, performance calculations, and understanding the aircraft’s behavior in flight. To calculate TAS correctly, you need to adjust the indicated airspeed (IAS) for the effects of altitude and temperature.

As altitude increases, the density of the air decreases, which impacts an aircraft’s performance and affects indicated airspeed. Specifically, indicated airspeed does not account for the fact that a higher altitude leads to thinner air. Similarly, temperature also influences air density; a colder environment can increase density, while warmer conditions decrease it. Therefore, to determine true airspeed, it is essential to adjust the IAS to give an accurate measure of how fast the aircraft is moving through the air at a specific temperature and altitude. This adjustment can typically be done using flight computer or specific formulas that factor in these elements.

The other options do not provide accurate methods for calculating true airspeed. Adding fuel weight to indicated airspeed or measuring ground speed does not yield true airspeed, and simply converting between units such as km/h and mph does not account for the necessary adjustments related to altitude and temperature that define TAS.