It's not so very long since even passenger aeroplanes followed railway lines to guide them along and pilots would read place names painted on station roofs. The smell of the local sewage works helped them fix their position, while air traffic controllers had a man on the balcony listening for aircraft engines. Craig Doyle tells the story of aircraft navigation and air traffic control.

For early aviators, any clue to their whereabouts was useful: from railway stations to the smell of a sewage farm

Fly Me to the Runway 11.00am R4
The only time air-traffic controllers hit the headlines is when they are on strike and you have to invent 60 different ways to amuse your children during the consequent donkey-age delay. Yet they are a highly skilled work force, operating complex machinery that juggles two million flights a year. But, as Holiday's Craig Doyle informs us, air navigation wasn't always an exact science. This two-part history begins with the plight of the early aviators. Planes were so fragile then, they could barely take the weight of the pilot, never mind a wireless, so flyers had to rely on their senses alone. To orientate themselves, aviators set a compass, laid out the map and crossed their fingers that there was a railway station that had its name painted in white on the roof. Even during the interwar years, some pilots would find their way by the smell of a nearby sewage works. Thankfully, the technology has improved a little since then - but they still haven't invented a way to make airport chairs less bum-numbing.