Plain English Meaning
A piece of equipment, on the ground or in space, that helps a pilot figure out where they are or where they need to go.
Full Definition
Any ground-based or space-based facility, transmitter, or visual device used by aircraft in flight to determine position, follow a course, or conduct an instrument approach. Common examples include VOR, DME, TACAN, NDB, ILS components, and GPS satellite systems.
Context Anchor
Pilots see this term in charts, flight planning, , instructions, and discussions of .