The staff at the airport face a race against the clock to process thousands of passengers arriving from 84 different countries. Airside safety officer Glenn and his colleagues are working closely with Air Traffic Control to keep the two runways open and clear.
Inside the terminals, the staff are dealing with an array of passengers including a man stuck living at the airport after being deported from Thailand, and a family who have lost their youngsters in arrivals.
Meanwhile, over at the Animal Reception Centre a variety of weird and wonderful animals are arriving and the staff find themselves contending with pet ferrets and a wild tiger!
Britain's Busiest Airport: Heathrow, ITV, 9pm
For exclusive competitions and amazing prizes visit Reveal's Facebook page NOW!