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

Equivalent airspeed (EAS) is a crucial concept in aviation that helps pilots understand the aerodynamic forces acting on an aircraft at a given altitude. It is defined as the airspeed at sea level that would result in the same dynamic pressure as the actual airspeed at altitude. To determine the dynamic pressure, EAS incorporates two significant factors: position errors and compressibility effects.

Position errors occur due to discrepancies in the aircraft's pitot-static system, which can arise from installation, airflow disturbances, or instrument calibration. These errors can lead to the difference between the indicated airspeed (IAS) and true airspeed (TAS). By accounting for these errors, EAS provides a more accurate assessment of aerodynamic performance.

Compressibility effects are particularly relevant as altitude increases. As the air becomes less dense at higher altitudes, the impact of air compressibility on the aircraft's performance becomes more pronounced. EAS helps normalize the airspeed measurements to consider these changes in density, allowing pilots to ensure safe and efficient operations.

In contrast, equivalent airspeed does not specifically account for environmental factors such as temperature fluctuations during flight, which are related to true airspeed instead. Therefore, the correct answer accurately highlights how EAS encompasses the important aspects of position errors and