Plain English Meaning

Any equipment outside the aircraft that helps a pilot figure out where they are, where they're going, or how to stay on course.

Full Definition

A ground-based or space-based facility, system, or device that provides pilots with information used for navigation, such as position, course, or distance. Examples include VOR stations, NDBs, DME, ILS components, and GPS satellites.

Context Anchor

Pilots encounter this term in flight planning, navigation procedures, charts, airport information, and notices about equipment that is working or out of .