Next on Episode 2

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.

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 passengers safe between take-off and landing.

What does it take to get a million people off the ground and up in the air? Explore the building of the world’s biggest passenger plane, how designers control the flow of passengers through the busiest airport on the planet, and the perils of getting airborne in the coldest city on Earth.