What is true altitude defined as?

True altitude is defined as the vertical distance above mean sea level. This measure provides a standard reference for various aviation applications, allowing pilots to ensure safe flight, especially when navigating terrain or communicating with air traffic control.

True altitude is crucial because it accounts for variations in atmospheric pressure and temperature that could affect the actual height of an aircraft above the ground. Unlike other definitions of altitude that might relate to the nearest airport, ground level, or specific altimeter settings, true altitude delivers a consistent and universally accepted metric vital for flight safety and navigation. This standardization means that regardless of environmental conditions, true altitude remains a reliable reference.