At any one time, a million people are airborne somewhere in the world. That equates to an entire city—a city in the sky. What does it take to run a city at 30,000 feet? To get 100,000 flights each day ready for take-off? To land them safely? Filmed around the world, this BBC miniseries uncovers the invisible global networks and complex logistics that make it all possible, from loading food, fuel, people, and luggage onto a plane, to staying airborne and avoiding collisions, to coming back down to earth. Seen on PBS. 3 episodes, 3 hrs, 1 DVD, SDH.