Plain English Meaning
An invisible sloping radio beam that tells the pilot whether they are too high, too low, or right on the proper descent angle to the runway.
Full Definition
The vertical guidance component of an Instrument Landing System (ILS) or similar precision approach. It transmits a narrow radio beam angled upward from a point near the runway touchdown zone, providing the pilot with a precise descent path to the runway.
Context Anchor
Seen in helicopter instrument procedure notes, , and limits that are based on how fast the helicopter moves the .