Big Arrows And Beacons; Navigating Across The United States By Plane In The Pre-GPS Era
It's the mid-1920's and you're in a plane trying to navigate your way across the vastness of the United States. GPS hasn't been invented yet. VHF Omni Directional Radio Range, shortened to VOR, hasn't been invented yet. LFR, or Low Frequency Radio Range, hasn't been invented yet. How do you hope to stay on course?
As a pilot you'd have a compass, an altimeter and maybe a map of the railway system to help you navigate and this is just what pilots did from 1918 when the U.S. Postal Service introduced the U.S. Air Mail system. But you needed one critical thing to help you navigate, one thing that wasn't available 24 hours a day. You needed daylight.
In 1921, an experimental night flight was successfully completed using the clever solution of following bonfires along the length of the route between Chicago and North Platte in Nebraska. The bonfires were lit and tended by Postal Service employees and the occasional helpful farmer.