The National Air Traffic Services (NATS) organisation responsible for air traffic control services at multiple airports in the UK is recovering from a technical systems outage at its Swanwick facility that caused significant disruption to flights on Wednesday afternoon.
In an initial statement issued at 4.05pm on 30 July, a NATS spokesperson described a technical issue that for safety’s sake, meant it had had to limit the number of aircraft flying in the London control area. The outage appeared to have been largely resolved by 4.25pm, NATS said.
“Our engineers have now restored the system that was affected this afternoon. We are in the process of resuming normal operations in the London area,” said the spokesperson.
“We continue to work closely with airline and airport customers to minimise disruption. We apologise for any inconvenience this has caused,” they added.
In a third update issued shortly after 5pm, NATS said: “Our systems are fully operational and air traffic capacity is returning to normal. Departures at all airports have resumed and we are working with affected airlines and airports to clear the backlog safely.”
The outage has affected airports across the UK, with delays reported in Bristol, Cardiff, the Channel Islands, Edinburgh, Liverpool, Manchester and Newcastle, as well as Gatwick, Heathrow, Luton and Stansted serving London.
Gatwick and Stansted representatives said the airports were still experiencing some residual delays as flights resume. Many airlines, including British Airways, are also understood to be temporarily reducing the numbers of planes they have airborne.
Meanwhile, stranded passengers have been describing hours spent sitting on the tarmac and flights diverted or made to return to their departure points.
IT failures
More information on the precise nature of the outage has yet to be made public but at the time of writing there is no credible evidence to suggest that it was the result of a cyber attack.
However, NATS has been dogged by a number of IT problems down through the years. A major failure in August 2023 caused after a badly formatted flight plan was input into the NATS system resulted in an inquiry and report conducted by the Independent Review Panel for the UK Civil Aviation Authority (CAA).
The report found that NATS’ systems acted as intended by placing themselves in backup mode so that they could not send potentially dangerous information to an on-duty air traffic controller, but that the backup systems that should have kicked in at that point effectively did the same thing.
This incident also left NATS unable to operate at full capacity, causing flight numbers to have to be limited and resulting in delayed travel for thousands of passengers.
A previous five-hour period of unscheduled downtime that occurred shortly before Christmas 2014 was found to have been the result of a software bug in a specific server used to update flight plan data that had been present since it was installed in 2002.
According to the BBC, Ryanair chief operating officer Neal McMahon has called for the resignation of NATS boss Martin Rolfe, alleging “continued mismanagement” and describing the disruption as “outrageous”.
McMahon said that no lessons appeared to have been learned from previous issues at NATS.
