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Flights disrupted after computer failure at UK control centre

Passengers are facing widespread flight disruption after a computer failure at the UK's air traffic control centre.

Nats said it was in the process of returning to normal operations after a "technical problem" at its Swanwick control centre caused delays and grounded some flights.

Problems were reported around the UK.

The government said the scale of the disruption was "unacceptable" and said it had asked for a "full explanation" of what had gone wrong.

This included delays at Heathrow and Gatwick, where departing flights were grounded for a time. Other UK airports reported knock-on effects.

It comes a year after a telephone glitch at the Hampshire control room caused huge disruption - one of a number of technical hitches to hit the part-privatised Nation Air Traffic Services since the centre opened in 2002.

Reported problems around the country include:

Heathrow: Fifty flights cancelled. Others delayed but planes now landing and taking off
Gatwick: Flights are now departing but still subject to delays
Stansted: Flights still landing, no flights departing
London City: Cancellations and delays
Luton: All flights experiencing delays
Bristol: Limited departures reported
Luton: All flights experiencing delays but planes now leaving
Edinburgh: No queues but passengers being advised to check with their airlines
Glasgow: Some delays to departures
Southampton: Experiencing ''problems''
Oxford: Experiencing "some delays", mainly to services arriving from overseas
Leeds Bradford: All flights out and most flights in suspended until 1900
Birmingham: Some departures are being re-routed to avoid flying through London airspace
East Midlands: Departures and arrivals delayed but passengers advised to turn up as normal

Nats' managing director apologised for the disruption and said it was still investigating the cause. Martin Rolfe ruled out a power outage, confirming there was a failure in the flight element of the system which left controllers with reduced data available to them. Mr Rolfe also said a computer hack had been ruled out.

Travel body Abta encouraged passengers expecting to take a flight to contact their airline.

British Airways said if its customers did not want to travel from Heathrow, Gatwick or London City on Friday evening they could rebook or get a full refund.

Vicky Lane, a passenger on a grounded London to Dublin plane at Gatwick said: "We've been stuck on a Ryanair flight... for over an hour. The doors are open and we're really cold. I'm not sure when we will be leaving."

Another passenger, on a flight to Paris, said his plane had "circled around the Lake District for half an hour before turning back to Edinburgh".

Ed Bott told the BBC he was: "Currently sitting on the tarmac. None the wiser. Waiting for news as to what's happening."

Swanwick controls the 200,000 square miles of airspace above England and Wales, cost ^623m to build, and employs about 1,300 controllers. But the facility, which handles 5,000 flights every 24 hours, has had a troubled history.

It opened in 2002, six years after its planned commissioning date - a delay which National Air Traffic Services (Nats) said was due to problems with the software used to power its systems. Almost a year after it opened, a senior air traffic controller raised concerns with the BBC about health and safety standards and complications with radio communications - which he said cut out erratically. Technical problems and computer faults hit flights in 2008 and again last summer. And, in December 2013, problems with the internal telephone system then caused further delays.

Aviation journalist David Learmount said the IT problem would cause "major disruption" but would be resolved by Saturday. "This impacts not just people within the UK, it impacts flights heading here from anywhere - anything heading this way will be told some of them can't be accepted, and they will have to go back to where they flew from or consider diverting to other countries," he told the BBC.

The RAF - which has its own air traffic control systems - said the UK military was unaffected.

According to one travel expert, the compensation bill from the disruption could run into tens of millions.

"The airlines will already be racking up the costs," Independent journalist Simon Calder told BBC News. "Simply refunding passengers' fares is going to cost them hundreds of thousands of pounds. The airline also has an unlimited duty of care to put people up in hotels, to feed them and everything else, until they can get them to their destination."

Flight disruption: Air traffic control glitch has been 'rectified'

A computer glitch that led to disruption across UK airports has been "rectified", the chief executive of the National Air Traffic Services has said.

Richard Deakin said a single line of code in one computer system at the UK's national air traffic control centre had caused the problems on Friday. But he warned updating some of its "elderly" systems posed a "challenge".

Flights have been returning to normal on Saturday, although almost 40 were cancelled at Heathrow. Passengers faced widespread flight disruption on Friday because of the technical fault in a flight data system at the Nats control centre at Swanwick.

The failure caused problems at airports around the country - including at Heathrow and Gatwick, where departing flights were grounded for a time.

Mr Deakin told the BBC that the software problem was "buried" among millions of lines of computer code. "The challenge is that we have around 50 different systems at Swanwick and around four million lines of code. This particular glitch was buried in one of those four million lines of code."

"We haven't seen that particular issue before," he added. He said Nats was spending an extra ^575 million over the next five years to bring its systems "up to date", but warned making improvements was a challenge as they had to be made "while the engine was still running".

Transport Secretary Patrick McLoughlin is due to be questioned by MPs on Monday about the chaos caused.

On Friday, he said the situation was "unacceptable" and asked for a full explanation from Nats about what had gone wrong and what it would do to prevent such an incident happening again.

Labour has called for ministers to "get a grip" and the Labour chairwoman of the transport select committee, Louise Ellman, said it was "vital that we establish what happened".

She said her committee, which will question Mr McLoughlin on Monday, would also call Nats and the Civil Aviation Authority to give evidence.

In a statement, Nats said the number of workstations "in use" at its control centre versus "in standby" fluctuated with the demands of the traffic being controlled.

"In this instance a transition between the two states caused a failure in the system which has not been seen before," it said. "The failure meant that the controllers were unable to access all of the data regarding individual flight plans which significantly increases their workload."

Nats said it then had to "reduce the traffic into and out of the UK network".

"The controllers had a full radar picture and full communications with all aircraft at all times during the incident and at no time was safety compromised in any way," it added.

The glitch caused delays at Heathrow and Gatwick, while other UK airports reported knock-on effects. Dozens of arrivals and departures at airports across southern England, and as far north as Aberdeen and Edinburgh, were delayed and cancelled.

On Saturday, Heathrow Airport said 38 flights due to arrive or take off before 09:30 GMT had been cancelled but the subsequent schedule was "back to normal".

A Heathrow spokesman said the cancelled flights could not be rescheduled because the airport ran at 98% capacity. He said passengers would be rebooked on other services.

British Airways said its Gatwick and London City flights were expected to operate as normal on Saturday and it was working to get Heathrow flights back on schedule.

Gatwick Airport said it hoped to operate a full service on Saturday although there would be "some backlog", while Stansted said all its flights were running on schedule.

Friday's problems came a year after a telephone failure at the Hampshire control room caused huge disruption - one of a number of technical hitches to hit the part-privatised Nats since the centre opened in 2002.

BBC correspondent Andy Moore said the issue only lasted for between 30 minutes and one hour but caused chaos because the UK's air traffic control system runs at 99% capacity.

Martin Clipp, a former senior operations manager at Nats, told BBC Radio 4's Today programme: "You can't build absolute resilience... in terms of the technology that backs up the systems. The system runs pretty much at full pelt. That means as soon as the slightest thing goes wrong the ripples go out enormously."

However, Mr Clipp said Nats was being required by the Civil Aviation Authority to cut costs, which had led to redundancies this year. "There is no risk in safety but there is risk in service continuity," he said. "You get what you pay for."

Air traffic boss denies 'complacency' over flight chaos

The boss of National Air Traffic Services has denied claims he was "complacent" over the flight chaos which hit 10,000 passengers on Friday.

Richard Deakin, chief executive of Nats, said he was "not proud" of the disruption but defended the response and back-up plan. Expecting systems to be failure-proof was "unrealistic", he told the Commons Transport Committee. He said 120 flights had been cancelled and 500 delayed in the chaos.

A computer glitch at the national air traffic headquarters in Swanwick, Hampshire, caused a system failure affecting mainly Heathrow, Luton and Gatwick airports.

(http://news.bbcimg.co.uk/media/images/79792000/jpg/_79792941_79792940.jpg)
Nats boss Richard Deakin was pressed over his annual pay packet

Transport Secretary Patrick McLoughlin described the problems as "unacceptable" in his evidence to the committee earlier this week.

Mr Deakin was repeatedly pressed by the Labour MP Tom Harris on whether he agreed with that assessment. "I think for those passengers it was unacceptable and from our point of view, yes, we're not proud of what happened on Friday night but I think we are proud of how we responded to it," he answered.

Mr Harris, a former transport minister, said Mr Deakin had come across as "incredibly complacent". "Your evidence so far has kind of given the impression that everything's fine..You seem to be suggesting that what happened Friday was a bit of a nuisance but you're ticking the box, you're taking a couple of hours out of your day to appear before us but after that it's fine," the MP said.

Mr Deakin denied the accusation, saying a "huge amount of time" had been spent making sure systems were performing to their absolute ability. He said the computer glitch had been identified and fixed and that particular problem would not occur again. However, he could not rule out other problems in the future. "Any complex system will have failures in it. I think it's unrealistic to expect that a system such as Nats never has any reduction in capacity due to those failures," Mr Deakin said. "They are rare...but we should take into account that sometimes systems do fail which is why we have back-up systems."

The Nats boss was also pressed over his pay package, confirming that he had received ^1.05 million, including a bonus of ^272,000, in the year to March 2014 - an increase of 46%. The bonus itself had been cut by 12%, he said, because of a previous air traffic control failure in December 2013.

Mr Deakin was appearing with Nats operations managing director Martin Rolfe and Andrew Haines, chief executive of the Civil Aviation Authority, which has already announced that an independent inquiry will be held into last Friday's failure.

Questioned about the independence of the inquiry, Mr Haines said it would be "highly independent".

Mr Deakin was repeatedly pressed by the Labour MP Tom Harris on whether he agreed with that assessment. "I think for those passengers it was unacceptable and from our point of view, yes, we're not proud of what happened on Friday night but I think we are proud of how we responded to it," he answered.

Mr Harris, a former transport minister, said Mr Deakin had come across as "incredibly complacent". "Your evidence so far has kind of given the impression that everything's fine..You seem to be suggesting that what happened Friday was a bit of a nuisance but you're ticking the box, you're taking a couple of hours out of your day to appear before us but after that it's fine," the MP said.

Mr Deakin denied the accusation, saying a "huge amount of time" had been spent making sure systems were performing to their absolute ability. He said the computer glitch had been identified and fixed and that particular problem would not occur again. However, he could not rule out other problems in the future. "Any complex system will have failures in it. I think it's unrealistic to expect that a system such as Nats never has any reduction in capacity due to those failures," Mr Deakin said. "They are rare...but we should take into account that sometimes systems do fail which is why we have back-up systems."