How does increased altitude affect true airspeed?

Increased altitude impacts true airspeed due to the decrease in air density as elevation rises. True airspeed refers to the actual speed of an aircraft relative to the surrounding air mass, which is affected by the density of that air. At higher altitudes, the air is thinner, which allows an aircraft to achieve higher true airspeeds. This is because, while indicated airspeed (the speed shown on the aircraft's airspeed indicator) may remain constant, the aircraft can cover more ground due to the decreased resistance from the less dense air. Therefore, as altitude increases, true airspeed increases slightly, making this the correct understanding of the relationship between altitude and airspeed dynamics.

In contrast, true airspeed does not significantly decrease with altitude, so it does not support the idea of a drastic reduction. Stating that it has no impact contradicts the principles of aerodynamics and air density. The notion of unpredictable changes in true airspeed does not align with the established relationship that as altitude increases, dense air decreases, leading to the observed slight increases in true airspeed.