In one of BBC Two's most ambitious live broadcasts, Kate Humble, Dallas Campbell and Anita Rani go airside at Heathrow, the world's busiest international hub airport. More than 200,000 passengers travel through Heathrow each day. Everything and everyone is on a deadline. Unprecedented behind-the-scenes access allows viewers to witness this daily relay race first-hand. The programme shows air traffic control in action and explains the extraordinary science and logistics behind every flight.