What does the term "true altitude" refer to?

The term "true altitude" refers specifically to the vertical distance of an object or point above mean sea level (MSL). This definition is crucial for flight operations, as navigating and ensuring safe separation from terrain and obstacles relies on accurate altitude information. True altitude is measured based on the average level of the sea, providing a consistent reference point for pilots across different geographic locations.

Understanding true altitude is essential in various phases of flight, particularly when responding to diverse atmospheric conditions. It allows pilots to effectively manage altitude in relation to altitude charts and terrain features, which contributes to safety.

The other options refer to different concepts related to altitude. For instance, altitude corrected for temperature variation addresses how atmospheric conditions can affect altitude readings, while the altitude displayed on the altimeter is reliant on the current barometric pressure settings. Pressure altitude relates to the altitude level based on a standard atmospheric pressure setting, which can also differ from the actual altitude concerning mean sea level. Each of these definitions serves its purpose, but they are distinct from true altitude, which is fundamentally linked to mean sea level.