Definition
A visual navigation aid at an airport that displays a rotating or flashing light signal to identify the airport from the air at night or in low-visibility conditions. The color and flash pattern of the beacon indicate the type of airport (for example, alternating white and green for a lighted civilian land airport).
Plain English
A rotating light at an airport that flashes a recognizable pattern so pilots flying at night can find the airport and tell what kind it is.
Context Anchor
Seen on or near airports and other landing areas, and commonly encountered in discussions of airport lighting and night flying.
Derivation
Aerodrome comes from the Greek 'aer' (air) and 'dromos' (course or running track) -- literally 'a course for aircraft.' Beacon comes from Old English 'beacen,' meaning a sign or signal. Together: a signal light marking the airport's location.
Why Pilots Care
Provides positive identification of the airport at night or in marginal visibility, reducing the chance of landing at the wrong field or becoming disoriented.
Intuition Check
Do not think of an aerodrome beacon as a runway light. It does not show the exact runway path; it helps identify where the airport or landing area is.
Example Sentence 1
On the night cross-country, the student spotted the aerodrome beacon flashing white and green about ten miles out and used it to line up with the field.
Example Sentence 2
Before departing on the night flight, the instructor pointed out the aerodrome beacon on the sectional chart so the student could use it for navigation.