A glitch in a single flight plan is believed to have caused the UK’s air traffic control meltdown on Bank Holiday Monday, the National Air Traffic Service (Nats) has confirmed.
There has been widespread speculation that the fault, which caused automated flight scheduling systems to fail, was caused by a French airline, although the actual source of the problem has still not been revealed.
But the revelation is sure to spark widespread calls for an inquiry – an almost identical five-hour system failure occurred in December 2014. It was found to have been caused by a bug in out-of-date technology dating back to the 1990s.
As investigations continue, Transport Secretary Mark Harper has eased rules that restrict night flights so as to allow airlines to get delayed passengers moving and help carriers restore schedules to normal.
More than 1,500 flights are believed to have been cancelled by the outage, according to data aviation company Cirium. Hundreds more journeys were axed yesterday (Tuesday) as airports and airlines struggle to clear the backlog and it is estimated as many as 250,000 travellers had their flights affected.
Nats chief executive Martin Rolfe said the system was now working normally.
“Initial investigations into the problem show it relates to some of the flight data we received,” he said.
“Our systems, both primary and the back-ups, responded by suspending automatic processing to ensure that no incorrect safety-related information could be presented to an air traffic controller or impact the rest of the air traffic system.”
Despite the reassurances, the whole incident has led IT experts to question why the system can be brought down simply by badly formatted information, suggesting that it runs on ageing technology.