In the late 1920's and early 1930's, powerful rotating beacons were installed at approximately twenty mile intervals along most of the major airways in the U.S. to facilitate night operations. Even as radio aids were developed, the use of these lights persisted in many parts of the country. A green light on the beacon denotes that it is placed on a landing field. A red light warns of no facilities at that site. This beacon serviced Brainard Field in Hartford until its removal in 1985.