Commercial Pilot License (CPL) 2025 – 400 Free Practice Questions to Pass the Exam

Flying at higher altitudes results in a decrease in atmospheric pressure and density. True airspeed measures the actual speed of an aircraft relative to the air it is flying through and is influenced directly by the density of that air. As altitude increases, the air becomes thinner, meaning there are fewer air molecules in a given volume. This lower density leads to an increase in true airspeed when maintaining a constant indicated airspeed, which is a measure based on the aircraft's pitot static system and does not account for changes in air density.

The reason indicated airspeed can remain stable while true airspeed increases is rooted in the aircraft’s performance and controls, which are designed to measure speed relative to the air around it at various altitudes. Therefore, flying at a higher altitude, with its reduced pressure and density, allows the aircraft to achieve a higher true airspeed even though indicated airspeed remains constant, emphasizing the relationship between altitude and air density on aircraft performance.