City in the Sky

What does it take to get a million people off the ground and up in the air? From building the world's biggest passenger plane to controlling the flow of passengers through the busiest airport on the planet, to the perils of getting airborne in the coldest city on earth...

We take flight for granted, but on any journey a hidden army of people keep your plane safe. We explore just what it takes to keep the 'city in the sky' airborne and safe between take-off and landing. How has flying become safer than ever before?

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.