Why does air traffic control keep failing?

Less up, up and away... more stuck on the tarmac. Hundreds of flights have been cancelled and thousands of passengers stranded after yet another critical collapse of the country’s air traffic control system.While a cyber-attack has been ruled out, it’s still the third time in four years severe disruption has affected airlines and travellers because of problems at NATS – a public-private partnership and the UK’s leading provider of air traffic control services.Why do these issues keep happening? Should the government intervene? And is it only a matter of time before passenger safety is compromised?Niall Paterson speaks to aviation expert and former air traffic controller, Doug Maclean.Have you got a question for Niall? Email us: why@sky.uk