The second episode of the series looking behind the scenes at Heathrow Airport, revealing the people, systems and science that keep us flying. Dan Snow is in the air traffic control tower, where controllers handle some 1,400 landings and departures every day. Dallas Campbell learns to hand-marshal a plane on the tarmac, and Anita Rani finds out how Heathrow trains to deal with extreme weather. Plus the programme follows, live, a shorthaul flight turnaround. The plane has just 45 minutes from landing until it takes off again.