Plain English Meaning

When you look at something from far away or at a low angle, it looks shorter than it really is. As you get closer, it stretches out to its true length. Pilots use this stretching and shrinking effect to judge distance.

Full Definition

A visual depth cue in which objects appear shorter or compressed along the line of sight as their distance from the observer increases. In flight, it causes runways, terrain features, and other landmarks to look squashed or flattened when viewed from far away or at a shallow angle, and to lengthen as the pilot gets closer or views them more directly.

Context Anchor

Seen in distance-estimation and depth-perception discussions, especially when judging runway length, spacing, or surface shape from the cockpit.