Plain English Meaning

A radio beam from the runway that tells the pilot whether they are too high, too low, or right on the correct descent path. The pilot follows it using a needle on the instrument panel.

Full Definition

A radio signal transmitted from the approach end of a runway that defines the correct vertical descent path to the touchdown zone, typically at a 3-degree angle. Pilots fly the path by keeping the glideslope needle on their instrument centered, using the signal as a vertical guide independent of what the runway looks like out the window.

Context Anchor

Seen during instrument approaches and when descent path on , especially when could make the runway look misleading.