Definition
A high-intensity rotating or flashing light installed at or near an airport to indicate its location to pilots at night or during periods of reduced visibility. The colour pattern of the beacon identifies the type of airport: alternating white and green for a lighted civilian land airport, white and yellow for a water airport, and two quick white flashes followed by a green flash for a military airport.
Plain English
A bright, rotating light at an airport that helps pilots find the field at night or in poor visibility. The colours it flashes tell you what kind of airport it is.
Context Anchor
Seen in airport lighting discussions, airport information, and night flying when a pilot is looking for the airport from the air.
Derivation
Aerodrome comes from the Greek 'aēr' (air) and 'dromos' (running course or track) — literally 'a course for flying.' Beacon comes from Old English 'beacen,' meaning a sign or signal, often a fire lit on a hill to guide travellers. Together: a signal light marking the place where aircraft operate.
Why Pilots Care
Enables safe navigation and airport identification when visual references are limited, reducing risk of disorientation or landing at the wrong field.
Intuition Check
Do not think of an aerodrome beacon as runway lights. The beacon helps you find and identify the landing area; runway lights help you see the runway itself.
Example Sentence 1
We picked up the airport's alternating white and green beacon about ten miles out and turned toward the field.
Example Sentence 2
During the night cross-country, the ABN provided a reliable visual reference for the destination aerodrome.