What term refers to the vertical distance of an airplane above the terrain, or above ground level?

• A. Absolute Altitude
• B. Relative Altitude
• C. Above-Ground Altitude
• D. Ground Altitude

Answer: (A)

The main idea is the height of the airplane above the surface below it. This vertical distance from the aircraft down to the terrain is what you think of as height above the ground. The term used for that height, the distance above the surface, is absolute altitude. It describes how high you are relative to the terrain itself, rather than relative to sea level.

In practice you’ll also hear it described as above-ground level (AGL), which is the same concept expressed in a different way. The other ideas aren’t describing the aircraft’s height above the ground: one refers to a height difference from another reference point, one would be the terrain’s own elevation, and another is a synonymless label that isn’t used for this measurement.