lennukõrguse

Lennukõrgus, meaning "aircraft altitude" in Estonian, refers to the vertical distance of an aircraft above a reference point. This reference point can vary, leading to different types of altitude measurements. True altitude, also known as absolute altitude, is the actual height above the ground directly below the aircraft. This is crucial for tasks like terrain avoidance and landing.

Another common measurement is pressure altitude. This is the altitude indicated when the altimeter is set to a standard atmospheric pressure of 1013.25 hectopascals (hPa) or 29.92 inches of mercury (inHg). Pressure altitude is used in performance calculations and air traffic control for establishing flight levels. Indicated altitude is what the altimeter displays directly, which is influenced by local atmospheric pressure. To obtain a more accurate reading of height above sea level, pilots will set their altimeter to the local barometric pressure, resulting in indicated altitude becoming QNH altitude, or mean sea level altitude. Density altitude is a derived parameter that takes into account pressure altitude, temperature, and humidity, and it represents the altitude at which the air has the same density. This is important for understanding aircraft performance, as higher density altitudes lead to reduced engine power and lift.