Airway Beacon
From Wikipedia, the free encyclopedia
Approximately 1,500[1] Airway Beacons were constructed, covering 18,000 miles [2] in the U.S. to guide pilots from city to city along airway corridors. Construction by the Post Office and the Department of Commerce occurred between 1923 and 1933. [3] They were spaced ten miles apart and featured a 24-inch parabolic mirror and a 110-volt, 1000 watt lamp.[4] In clear weather they could be seen for 40 miles.[5] The beacons rotated at 6 rpm, creating a flash every 10 seconds for 1/10th second duration.[6] The St. Paul Beacon sits on top of a 110 foot steel tower in Indian Mounds Park and is believed to be the last of these beacons in existence.[7] The radio navigation beacon system began to replace this visual system in 1929.[8] The last visual airway beacon was shut down in 1973.[9]
