The Radio Beacons That Mapped the Sky: The Rise and Fall of the VOR

Before satellites, navigating an airplane across a continent meant following a web of ground-based radio stations, and the workhorse of that web was the VOR — the VHF Omnidirectional Range. First deployed in the United States in the mid-twentieth century, VOR stations transmit signals that let an aircraft's receiver determine its bearing to or from the station along any of 360 radials, like spokes on a wheel. String enough VORs together and you get airways — published highways in the sky, defined as segments running from one beacon to the next. For decades a cross-country flight was flown by tuning successive VORs and tracking their radials, the cockpit needle swinging to confirm each leg. The system was a vast improvement over the earlier light beacons and low-frequency ranges, offering course guidance largely free of the static and night effects that plagued older methods. VOR navigation has limits. The signal travels line-of-sight, so range shrinks at low altitude and behind terrain, and the network requires hundreds of maintained ground stations. Satellite navigation removed those constraints: GPS provides precise position anywhere, at any altitude, without a chain of beacons, and enables direct routings that ignore the old spiderweb of airways entirely. As a result, aviation authorities have been decommissioning VORs while deliberately preserving a "minimum operational network" as a backup for the day GPS is jammed, spoofed, or fails. The radials that once defined the structure of the sky are fading into redundancy — but not quite into history. They remain a reminder that for fifty years, pilots found their way across oceans of air by listening for the right station.