A Guiding Light: The Airway Beacon Tower

In 1905, Rudyard Kipling authored With the Night Mail: A Story of 2000 A.D., a science fiction tale detailing various aspects of domestic and international commercial airship travel ninety-five years into the future. A prominent feature of Kipling’s worldbuilding was a system of light beacons, some strong enough to bore holes through clouds, that guided blimps to their destinations. Less than twenty years later, his vision was already happening in the United States. The Post Office and Army Air Service pioneered airmail services near the end of World War I, but quickly discovered that navigation could be a potentially significant problem.

As airmail pilots learned to follow “the iron compass” (railroad tracks) in the early years after World War I, they had little support. Attempts to formalize government control over aviation languished in Congressional debate and were not resolved until 1926 with the passage of the Air Commerce Act. Nonetheless, the Post Office worked to connect the coasts by designated routes called airways. The first pioneering pilots flew the airways during the day without purpose-designed maps. (Only in 1923 did airmail pilots begin to have access to Army Air Service “Strip Charts” for navigation.) This presented a problem for the U.S. Post Office: Without flying at night, airmail was slower than by railroad and the higher cost of air transport had no value.

The first significant experiment to see what would be required to fly across the country without stopping at sunset occurred on February 22, 1921. Planes, each starting on opposite coasts, flew the route between New York and San Francisco. Night navigation was to be by bonfires scattered along the route. Only one mail plane, piloted by Jack Knight and equipped only with a railroad map and compass for navigation, actually completed the flight. A misunderstanding caused the Omaha bonfire to remain unlit and Knight almost ran out of gas before finding the landing field. He made the trip in a mere 33 hours and 20minutes (about the same time it took Lindbergh to fly from New York to Paris only six years later). This was still faster than the railroads, though. The experiment with bonfires was not repeated, though a mythology grew up decades later that airmail pilots flew with bonfires routinely.

The experiment showed that the Post Office required a better system, but Congress was slow to fund the infrastructure. By early 1923, the Post Office was using hybrid air and railroad carriage for transcontinental service with airmail pilots carrying mail in the daytime at the rate of 50 million letters per year, and trains carrying it the rest of the way at night.  Another experiment occurred in July and August 1923 when the Army Air Service constructed a chain of small beacon lights between Dayton, Ohio, and Columbus, Ohio, and successfully flew night runs. A year later, this experiment led to a permanent chain of more substantial beacon lights between Chicago, Illinois, and Cheyenne, Wyoming. By July 1925, the entire route between New York and Chicago had been equipped with light beacons along the route.

The long-delayed passage of the Air Commerce Act finally allowed a massive uptick in beacon construction with the introduction of acetylene-powered beacons equipped with Fresnel lens for maximum visibility, located every ten to fifteen miles along the airmail airways. By 1931, the airways had reached maturity with new standards and technologies providing safe guidance for mail planes and the increasing number of passenger airliners. At the high point of the lighted airways in 1946, 2,112 beacons operated along 124 airways in the United States.

Of course, beacons did not guide airplanes flying in or above the clouds. Instead, a system of four-course radio ranges overlaid many of the airways, which in turn gradually rendered the airway beacons obsolete. Even though the last federal airway beacon shut down in 1972, beacons still operate at airports to give pilots a visual identification of the airfield at night. The last federal airway beacon decommissioned found its way to the National Air and Space Museum where it has been in the America By Air gallery for over a decade until recently. It once guided pilots transiting the pass between Mount San Jacinto and San Gorgonio Mountain in California. The beacon is currently in the Mary Baker Engen Restoration Hangar to undergo conservation treatment before eventually returning to an entirely new America By Air gallery as part of our transformation of the Museum in DC.