There are around a million people airborne at any one time. But what goes up must come down - and getting passengers safely back to earth depends on complex global networks and some astonishing technology.Premiere Date: February 22, 2017 | Runtime: 00:00:30
At any one time, there are a million people airborne somewhere in the world. That equates to an entire airborne city - a city in the sky. So what does it take to run a city at 30,000 feet? In this series, we set off around the world to uncover the invisible global networks and complex logistics that make it all possible.