In March 1927, an article in Scientific American, under the heading ‘Invisible Beams Guide Birdmen in Flights Between European Cities’, noted admiringly how pilots in Europe could fix their locations instantly via radio beacons. Lost American pilots, by contrast, had to search for a town and hope that someone had written its name on the roof of a building. In the absence of that – and it was generally absent – pilots had to swoop low to try to read the signs on the local railway station, often a risky manoeuvre.
