There are other accurate systems for navigation available for aircraft, like the network of Non-Directional Beacons (https://en.wikipedia.org/wiki/Non-direction

There are other accurate systems for navigation available for aircraft, like the network of Non-Directional Beacons (https://en.wikipedia.org/wiki/Non-directional_beacon https://en.wikipedia.org/wiki/Non-directional_beacon). It's a bit more of a pain in the butt to fly, because you're going from waypoint-to-waypoint, rather than a course relatively towards your destination, but it was how we did aircraft navigation up until relatively recently.