Skip to main content
No. 2130:
Before GPS

Today, what did we do before GPS? The University of Houston's College of Engineering presents this series about the machines that make our civilization run, and the people whose ingenuity created them.

CCross country flying was a real challenge in the 1920s. Pilots flew with maps in their laps, trying to relate the limited features on paper with the ambiguous reality unfolding below them. Pilots often landed in pastures to ask farmers for directions. Two-lane highways and small towns all looked alike from up in the sky. What to do? Well, Air and Space writer Roger Mola tells us.

The Government began promoting a remarkably straightforward solution in 1926. Simply paint names of towns on roofs of barns, buildings, water towers, gas storage tanks, and hangers. Paint the letters ten to thirty feet high -- black on a chrome yellow background. Include an arrow pointing to the nearest landing field.

The hope was to place these markers every fifteen miles. By the time I was a boy, taking long automobile treks with my parents, we saw these signs all the time. Well, we saw them at an angle, when they'd been painted on sloping roofs. 

But where to get the labor for this huge task? It had to begin as a volunteer program. Later, during the Depression, the CCC and the PWA were called in. But it started out as civic volunteerism. The Boy Scouts gave a merit badge for taking part in it. Mola quotes this bit of doggerel from Scouting magazine:

Markers keep you safe from harm,
Tell of towns and ports nearby,
Tell the mileage you must fly,
Give your longitude and latitude,
Give you everything but altitude.

No matter the iffy iambs and dactyls (or whatever they're called.) It trumpets the ambition of the program to go beyond mere town identification. Program supporters created a media blitz. Radio personalities Amos and Andy, both flyers, took up the cause as part of a campaign called, "Let the air know you're there."

One organization, The Ninety-Nines, gave powerful support. That group, formed in 1929 by the first 99 licensed women pilots, strongly promoted the program. Local chapters of The Ninety-Nines went out with paint and brushes to do the actual labor. 

Then: Pearl Harbor. In the early days of WW-II we seriously feared bombing, even invasion, from both the Atlantic and the Pacific, and we'd created a clear aerial road map for the enemy. The government waffled for a month and ten days, then came down with a directive that all markers were to be eradicated within 150 miles of both coasts, and no new markers were to be painted. That was soon amended to leave markers in a fifty mile radius around flight training fields. We didn't want trainees getting lost and killed.

The war was still going on in 1944, but now the allies had clear air superiority. So the marking program was reinstated, this time with longitude and latitude numbers included.

Well, we've now come far beyond such direct navigational aids. But I thought you might like to know that there really was life in America before GPS systems were there to light our many paths. 

I'm John Lienhard, at the University of Houston, where we're interested in the way inventive minds work.

(Theme music)

R. A. Mola, Show Me the Way to Go Home. Air & Space, Sept. 2006, pp. 54-57.

painted hangar

The Tillamook Air Museum also carries on the tradition today. (There is a small adjacent airfield.) One gains some idea of the size of these letters when one learns that the hanger is a quarter of a mile long.  (photo by JHL)