Plain English Meaning

A ground-based radio system that gives a pilot two guidance signals during the final approach: one telling them if they are left or right of the runway centerline, and another telling them if they are above or below the correct descent path. Together, these guide the aircraft down to the runway when the pilot can't see it clearly.

Full Definition

A precision approach navigation system that provides pilots with horizontal (lateral) and vertical guidance to a specific runway, allowing approach and landing in low visibility or low ceiling . It typically consists of a for runway centerline , a for guidance, and or for information along the .