What is an Aeronautical Beacon?

Ever notice colored flashing lights at the top of a tower structure at an airport or landmark? Or maybe wondered how a pilot knows the difference between airports and landmarks at night? The aeronautical beacon is one of the ways pilots can differentiate the different locations by the colors of the beacons.

Airport Beacons: Not what they used to be.

Hearing the word airport and beacon together in the 21st century might make you think about Wi-Fi hotspots in a large terminal, but that wasn’t always the case. 100 years ago, airmail pilots flying biplanes had to find their way without any modern electronics. Flying over the dark prairie to deliver mail at night was a dangerous occupation.

In 1919 an Army airman by the name of Donald Bruner had farmers and mail employees light a series of bonfires he could follow to his destination at night. By 1923 the Post office had completed a network of lighted beacons every 15 to 25 miles meant to be bright enough to be seen for 40 miles, depending on the weather of course.

Airports were identified by rotating beacons. While the stationary beacons have been lost to history, airports still use rotating beacons today! At night you can see them, but they are also sometimes on in the day time when the ceiling is less than 1,000 feet or the ground visibility is less than 3 miles. Here are the color combinations of beacons still in use today to identify airports.  Certainly not necessary with today’s electronics, but there for a pilot to follow home on a rainy night just in case.

2 Lights

White and Green = Lighted land airport

White and Yellow = Lighted water airport

White and Red = Landmark or navigational point

3 Lights

Green, Yellow, and White = Lighted heliport

White, Green, Amber — Hospital and/or Emergency Services Heliport

White, White, Green = Military Airport

Although the same color combination as lighted land airport beacons, they are differentiated by two quick white flashes between the green flashes.