What is the aviation definition of altitude?

The aviation definition of altitude refers to the distance above a specific reference point, and in this context, it is related to the local pressure setting. Altitude is typically measured in relation to the pressure at sea level and is referred to as "pressure altitude." This measurement is crucial for pilots as it assists in ensuring that they are flying at safe and efficient levels, especially given that atmospheric pressure changes with weather conditions and altitude.

When flight operations use the local pressure setting, it allows for accurate altitude readings that reflect the actual air pressure at that location, aiding in navigation and safety. Hence, distance above the local pressure setting captures the essence of how altitude is utilized in aviation, aligning with regulatory and operational standards that ensure safe flight operations.