UK flight delays

The Register reports that the problems that beset Britain’s air traffic control system on Saturday was due to a technical fault with a touch screen interface provided by Frequentis.

On Saturday 7 December, passengers in Britain suffered cancellations and delays when controllers at NATS (National Air Traffic Services) operations room in Swanwick noticed that their system had suddenly stopped working. Southern England was particularly badly affected as the airways in the South are far more congested than elsewhere.

So what went wrong?

The Register investigated and reports: -

“The outage on Saturday was caused by a problem with a Frequentis system that enables our controllers to talk to other parts of the operation,” a spokesman at NATS said.

“It uses a touch screen interface that automatically loads all the contacts – around NATS and in other agencies involved in the air navigation network – that a controller will need for the particular piece of airspace that they’re controlling at that time.

“It therefore ensures they can always immediately reach the person they need to speak to and will reconfigure itself with settings specific to the sector that the controller is responsible for when they log in for their shift.”

But during Saturday’s routine shift change, the system – which has been used by NATS for 11 years – collapsed, forcing the controllers to ground aircraft while engineers attempted to fix the error.

It’s understood that the touchscreen telephone system failed to configure correctly so that new positions could be opened to split the extra sectors needed for daytime airspace control.

Delays were reported at airports including London, Cardiff, Edinburgh, Glasgow and Dublin. NATS said at the time that the glitch had not compromised passenger safety, but some questioned why contingency didn’t fully kick in when the system failed.

NATS said on Saturday:

The technical and operational contingency measures we have had in place all day have enabled us to deliver more than 80 per cent of our normal operation. The reduction in capacity has had a disproportionate effect on southern England because it is extremely complex and busy airspace and we sincerely regret inconvenience to our airline customers and their passengers.

To be clear, this is a very complex and sophisticated system with more than a million lines of software. This is not simply internal telephones, it is the system that controllers use to speak to other ATC agencies both in the UK and Europe and is the biggest system of its kind in Europe.

It added that it had worked closely with Frequentis to get the system up and running. But by Monday morning, following a weekend of political pressure about the outage, NATS boss Richard Deakin admitted that an inquiry into the resilience of the UK airspace was needed.

“We are keen to do all we can at NATS to ensure the aviation industry has a full understanding of the capability that is in place in the UK and to take any further steps our customers and regulators decide are necessary to help avoid a repeat of last Saturday’s problems,” he said.

The issue was eventually resolved after 14 hours with NATS claiming that over 90% of flights booked to travel on Saturday eventually did so.

The full Register article is here.

Flight delays today to persist until at least 14:00hrs

London Heathrow, Gatwick, Stansted, and Dublin airports are amongst those affected, due to a technical issue at the Sandwick Air Traffic Control Centre. Passengers are experiencing flight delays and cancellations.

Heathrow Airport had cancelled 60 flights by 9:45am this morning.

Some long haul flights inbound will be diverted to continental airports.

When the issues are fixed there will be a further period of disruption while services are re-arranged.

For live information BBC News.

As at 10:30am the BBC reported that BA customers on cancelled flights will be able to claim a full refund or be re-booked on an alternative flight.