In the days before radar and computers, pilots used compasses et al to ensure they were flying in the correct direction. As well, aviation charts were few and far between… and even then, they may not have been very accurate, so pilots would try and find landmarks to help guide them along the way from point A to point B.
But… leave it to the United States Postal Service to come up with a simple solution.
Way back when… with airmail still in its infancy, the United States opened up its first coast-to-coast airmail route on August 20, 1920… which is 60 years after the Pony Express stopped its service thanks to the advent of the railroad cutting a swathe across America… the Post Office created the world’s first ground-based navigation system.
Trust me – I just made it sound waaaaaaay more complex than it really is.
While I wondered why pilots couldn’t just sort of eyeball a set of railroad tracks when heading east or west, I realized that cloudy, drizzly or snowy weather could put a halt to the delivery of mail by air. And night flying? Forget it.
So… to combat the elements, the US Post Office decided to create a road map that pilots could follow from New York to San Francisco – and visible from the reaches of the wild blue yonder.
They made a giant map using big yellow arrows on the ground, that a pilot could see from the sky – placed every 10 miles.
Yup… big yellow concrete arrows. And just beside each arrow on the ground would be a 51-foot steel tower that held a 1-million candlepower rotating beacon. A generator shed was built at the tail of each concrete yellow arrow that housed a generator to power the beacon.
No longer did pilots have to stop for darkness… now they could fly cross-country in just 30 hours or so… meaning sleep deprivation was now something a pilot had to be concerned about. No one ever thinks about stuff like that, do they?
“Here, ya go pilot… here’s the mail, a sandwich, a thermos full of coffee, some amphetamines… and when you have to pee, drink your coffee. Do not take a crap or you will ruin the thermos for the pilot on the return flight.”
Just follow the yellow brick road was an easy mantra for pilots who would not have heard of The Wizard of Oz for another 16 years.
US Congress provided funds for another map line of yellow concrete arrows in 1924, stretching from Rock Springs, Wyoming and east to Cleveland, Ohio.
A year later, it was continued further east to New York… and then all the way coast-to-coast by 1929.
Thanks to advances in radio and radar as navigation technology, the beacon towers beside the yellow arrows were decommissioned in the 1940s. The steel towers were torn down and made part of the steel drives for the US war effort, after it finally got off its ass to join WW2 over two years after it began. And then it kicked major ass, of course… but two years of not being involved… sigh.
The arrows remain of course. But the yellow paint on them has faded away… but if you look carefully from the sky, you can still see them pointing ghosts in the right direction.