The UK’s air-traffic control system failed in response to a faulty flight plan, the boss of Nats has told The Independent.
Martin Rolfe, chief executive of the air-traffic control service, revealed for the first time that the fault was initially identified at 8.30am on Monday – almost three hours before the automatic system went offline, leaving controllers to handle aircraft manually.
The system is designed for caution when confronted with anomalous data. Rather than risk air-traffic controllers being presented with false information, the system went into its back-up mode – which stores up to four hours of data.
“We were working on a timeline of restoring the system before 12.30 [pm],” Mr Rolfe said.
“But obviously, as you will appreciate, we’re not getting new flight plans in at that stage – or only those flight plans we can manually process. So effectively you erode the store of data.
“We knew that if we hadn’t solved it by that point, we would be in the situation where we needed to significantly reduce the flow of aircraft to make sure we didn’t overwhelm the system and more particularly the controllers.
“Probably about halfway through that, we concluded that there was a reasonable chance that we might not be able to recover it in the timeframe. The problem was significantly different from anything we had seen before, and of course that always raises questions as to what the cause was.
“It is only in circumstances where things are so outside of what we expect to see that we would revert to manual operations.
“At the time we had no idea. We have a better idea now, but at the time we didn’t. So we started to invoke contingency procedures: talking to airlines, talking to the Dft [Department for Transport], talking to the CAA [Civil Aviation Authority] to make it clear that there was a potential for a significant problem.
“Being a bank holiday, we knew that was pretty likely given the volume of traffic.
“The engineers managed to figure out what the problem was to the point of being able to say ‘we know how to fix it’ – which is not the same, obviously, as the root cause.
“By 1.30[pm] there was news from the engineers that they thought they knew how to effectively recover the system, despite not knowing the root cause.”
Within a hour the system was working again, he said – but “you don’t go…
Click Here to Read the Full Original Article at The Independent Travel…