What is the term for height above the standard datum plane?

The correct term for height above the standard datum plane is pressure altitude. This measurement is determined by the barometric pressure and is used in aviation to report altitude in relation to a standardized atmospheric pressure. Pressure altitude is crucial because it allows pilots to determine their altitude based on the aircraft's altimeter setting, which is adjusted to a standard atmospheric pressure of 29.92 inches of mercury (Hg) at sea level.

This standardized system helps ensure consistent altitude reporting across different aircraft and is particularly important for maintaining safe separation between aircraft during flight. It also plays a significant role in performance calculations, engine efficiency, and fuel management.

While true altitude refers to the actual height above mean sea level, density altitude is the pressure altitude corrected for non-standard temperature, and absolute altitude refers to the height above the ground level or terrain. In contrast, pressure altitude is specifically tied to the standard datum plane, making it the correct term in this context.