An aeronautical beacon used to aid in locating the aerodrome from the air (ICAO). It displays flashes of white and/or colored light. These flashes indicate the location of an airport, a heliport, a landmark, a certain point of an airway in mountainous terrain, or an obstruction. Beacons flashing at the rate of 12 to 30 flashes per minute mark airports, landmarks, and points on airways whereas heliports are indicated by beacons flashing at 30 to 60 flashes per minute. The colors and meaning of the more commonly used beacons are as shown in the illustration.