Definition
A ground-based or space-based installation that transmits signals used by aircraft to determine position, track, or course. Examples include VOR stations, NDBs, ILS components, DME stations, and GPS satellites and their supporting infrastructure.
Plain English
A station, beacon, or satellite system that sends out signals pilots use to figure out where they are and where they are going.
Context Anchor
Seen in instrument flying when a navigation instrument is showing the airplane’s position or course in relation to a selected source of guidance.
Derivation
From Latin 'navigare' (to sail or steer a ship) and 'facilis' (easy to do). A 'facility' in this sense is something that makes a task possible — here, the equipment that makes navigation possible.
Why Pilots Care
Accurate use of navigation facilities keeps the aircraft on course and prevents disorientation when outside visual references are unavailable.
Intuition Check
Do not assume facility means a building. Here, it means a source of navigation information, such as equipment or a signal used by the aircraft.
Example Sentence 1
Before beginning the approach, the pilot tuned the navigation facility's frequency and confirmed its identifier in Morse code.
Example Sentence 2
Cross-checking two separate navigation facilities confirmed the aircraft position during the approach.