To illustrate how thoroughly they've researched it, one of the reporters stated in 'What's on TV' that the controllers at Heathrow must have very strong bladders to do their job ( or something similar) She obviously wasn't aware that under CAA regulations, controllers MUST have a break at least every 2 hours, and must have 30 min rest for every 2 hours of operational duty.
Anyway why is it always Heathrow they choose to do these programmes; why not an airport with busy mixed traffic like Biggin or Gloucester?