Definition
A visual navigation aid located at an airport that rotates to produce alternating flashes of light, identifying the airport at night and during periods of reduced visibility. The color combination of the flashes indicates the type of airport: alternating white and green for a lighted civilian land airport, alternating white and yellow for a lighted water airport, alternating white, white, and green for a lighted military airport, and alternating white and green plus a steady green or yellow flash for a lighted heliport.
Plain English
A bright rotating light at an airport that flashes specific colors so pilots can spot the airport from far away at night or in poor visibility, with the color pattern telling them what kind of airport it is.
Context Anchor
You will see airport rotating beacons while approaching or looking for an airport, especially at night or in reduced visibility.
Derivation
Beacon comes from the Old English 'beacen,' meaning a sign or signal. Long before aviation, beacons were fires lit on hilltops to guide travelers or warn of danger. The same idea carries forward: a strong, visible signal that helps people find their way.
Why Pilots Care
Provides positive visual identification of an airport from several miles away, supporting safe VFR navigation and night operations where other visual cues may be absent.
Analogy
It works a little like a lighthouse for pilots: you may see the rotating light before you can clearly make out the airport itself.
Intuition Check
Do not assume “beacon” means any bright light on the airport. In this context, it means the rotating airport identification light used to help pilots locate and recognize the airport.
Example Sentence 1
On the night cross-country, the student spotted the alternating white and green beacon and confirmed the airport's position before entering the pattern.
Example Sentence 2
During a cross-country flight, the beacon helped confirm the correct airport before entering the traffic pattern.