The technical issues that sent UK air traffic control into meltdown earlier today have been resolved.
But with tales of delays and cancellations reaching us from the UK, mainland Europe and beyond, the impact of the hours-long outage seem far from over.
We will, of course, follow closely the fallout in the coming hours as well as hopefully get a greater understanding of what went wrong. In the meantime, you can keep an eye on the latest developments in our story here.
And for those of you with whose flights are affected, here's a guide to your rights.
For now, that's it from us in London. Today's writers were Thomas Mackintosh, Antoinette Radford, Ali Abbas Ahmadi, Emily Atkinson and Krystyna Gajda. The editors during the course of the day were Dulcie Lee, James Fitzgerald, Rob Corp and Heather Sharp.
The story of the day
EPACopyright: EPA
So, air traffic control service Nats is now promising to investigate "very thoroughly" what caused the four-hour outage which has had such a huge impact on air travel today. We're wrapping things up here at London Broadcasting House. In the meantime, here's a recap of the key developments:
The "technical issues" that emerged around noon were "identified and remedied" by mid-afternoon
But today's flight delays and cancellations promise knock-on effects for days to come, with passengers telling the BBC they may not be able to return home until later this week
Others tell us they are seeking alternative routes home, ditching the planes for journeys by road and rail
British Airways, Jet2.com, Ryanair, EasyJet, Wizz Air, Loganair and Aer Lingus in turn issued statements apologising for the inconvenience, careful to make the point that the disruption was out of their control
Aviation analysts Cirium estimate that more than 500 flights into and out of the UK were cancelled as of 14:30 BST
Transport Secretary Mark Harper said a short while earlier that flights were still "unfortunately affected", casting doubt over travel plans for the rest of the week
We will continue to cover this story as it develops in the coming hours and days.
As a reminder, if you have been badly affected by these events, we would be keen to hear from you. Get in touch by emailing haveyoursay@bbc.co.uk
'Quite a rare event' - air traffic control expert
Air traffic control expert Doug Maclean, who has nearly 40 years' experience, has been speaking to the BBC about what went wrong.
"The flight data processing system is really vital to running the volumes of air traffic that go through UK and European airspace," he says.
"When a plane is coming from say Milan to London, all the air traffic control centres will receive the flight plan from the plane. As it gets airborne, it'll be updated on the way".
It's when it breaks down, that you have to put the details in of every flight by hand.
"It's now become quite a rare event," he says.
"Dare I say it - probably 10 or 15 years ago, it was much more common."
Travel alternatives are 'tripling in price'
Carl is a teacher who is trying to get to Heathrow from
Munich.
His original flight was cancelled and the earliest flight to Heathrow is on Thursday.
He’s told BBC News he's now travelling to
Amsterdam to get a flight back to the UK on Wednesday.
"People are trying all sorts of routes - watching flights, ferry tickets and
Eurostar tickets disappear in front of your eyes, or tripling in price is
stressful," he says.
"I am trying to get home to prep for teaching next week. I'm losing two days work now and all my relaxation has gone."
Who pays for a hotel if you're stranded?
PA - Rory DollardCopyright: PA - Rory Dollard
Rory Dollard's wife Joanne, and children Emily, 10, and Arthur, eight, waiting for updates at Bergerac Dordogne Perigord AirportImage caption: Rory Dollard's wife Joanne, and children Emily, 10, and Arthur, eight, waiting for updates at Bergerac Dordogne Perigord Airport
A British journalist who faces being stuck in France for up to six days is concerned about the uncertainty over who will pay for an extended stay following today's airline disruption.
Rory Dollard, cricket correspondent at PA Media, says he and other passengers stuck at Bergerac Dordogne Perigord Airport have heard "absolutely nothing" after the technical fault at air traffic control meant Ryanair could not bring them back to the UK.
He says he's been told it may take up to six days before he and his wife and two children can get home.
"I've never been in a situation like this before, and because of the language barrier, it's hard to work out exactly who's responsible for which part of the cost," he says.
"If you need to find a hotel for the next five or six nights, who's paying for this? Is it Ryanair? Is it your insurer? Is it somebody else?"
Stranded couple consider returning to Stuttgart by train
One stranded couple are considering returning home to Stuttgart by train after their flight from London was cancelled.
Myria Mebold, 36, also tells the PA news agency that British Airways "didn't know anything at all" when she and her husband asked about the situation and their flight.
"We are waiting for any information and checking if we can go back by train or anything, I don't know. Somehow we have to get back home."
When she asked BA staff for help, Mebold said they told her to come back at 6pm and "maybe then they can give more information."
"It was a nice day in London but now it is starting to get annoying."
She said the flight had been delayed to leave the UK after 1am on Tuesday, but planes cannot land at Stuttgart during the night.
Its operations director, Juliet Kennedy, explains "the automatic system, which provides controllers with details of every aircraft and its route wasn't working" and "instead to manage safety we had to limit the number of flights we could manage".
She says Nats' teams "worked hard to resolve the problem" but "it will take some time for flights to return to normal".
"We will continue to work with the airlines and airports to recover the situation," she says.
"Our absolute priority is safety and we will be investigating very thoroughly what happened today," Kennedy adds.
We are duty-bound to remind anyone reading this page that while there is no specific limit on how much you can drink on a flight, it is a criminal offence in the UK to be drunk on board an aircraft.
Getty ImagesCopyright: Getty Images
Where are we up to?
We launched our live coverage of the "technical issues" affecting UK air traffic control just after midday. More than seven hours in and, while delays are continuing, the actual cause of the disruption has been fixed.
A lot has happened so here's a reminder of the key developments:
Nats released a statement shortly after midday saying there was a problem which meant they were having to limit the number of aircraft they could handle
Airlines and airports began warning of lengthening delays and advising passengers to check the latest information before heading out
The BBC began receiving reports from passengers - especially those overseas - who were either facing long waits or having their return flights cancelled.
Just after 15:30 BST, UK air traffic control service Nats announced it had "identified and remedied the technical issue"
But the promising news was tempered by Transport Secretary Mark Harper, who said that despite fix, flights were still "unfortunately affected"
Delays and cancellations ensued, with British Airways advising short-haul passengers not to travel to the airport unless their flight is shown to be operating
We've heard from many frustrated passengers across the day, including one mother who, accompanied by her six-year-old, had faced two flight cancellations in two days
And another woman told us she had missed a heart transplant check-up after her flight was cancelled from Belfast Airport
Jet2 cancels some outbound flights and warns of 'significant delays'
An update now from UK holiday airline Jet2.com, which says it has taken the decision to cancel some outbound flights today.
In a newly updated statement, the carrier also warns of "significant delays" ahead for passengers travelling to and from the UK.
"Our teams are working incredibly hard to communicate with, and look after, our customers and they will continue to do so," it adds.
Jet2.com says it will be contacting all affected customers to let them know. Affected passengers will also receive a full refund.
"We are extremely sorry to have to take this decision however the ATC disruption leaves us with no other choice."
The airline says it is reviewing Tuesday's flights and will update customers in due course.
"Customers due to travel tomorrow should travel to the airport as normal unless we advise otherwise, and continue to monitor Flight Information on our website," the statement continues.
"We would of course like to apologise to everyone that is affected by this situation, which is unfortunately completely outside of our control."
'EasyJet have been poor'
Richard Ockenden and his family, from Preston, were due to travel back from Lisbon to Manchester
this evening.
Like many others, their EasyJet flight was cancelled.
The family are now driving north through Portugal to Porto where their return flight is scheduled for
9pm tomorrow, while trying to arrange accommodation for the night ahead.
"There
has been no communication from [EasyJet] beyond notifications on their app," Richard tells the BBC. "The app offers to find you accommodation but there is nothing available.
"EasyJet
have been poor," he adds.
"All
this with a very tired one year old and an excited five year old as we get an 'extra day' of holiday."
In a statement shared earlier, EasyJet said: "While these circumstances are outside of our control, we would like to apologise for the inconvenience caused and to reassure customers that we are doing everything possible to minimise the impact of the disruption."
Woman misses heart transplant check-up over flight delay
Serena Hamilton, from Cookstown, is expected at the Freeman Hospital in Newcastle-upon-Tyne on Tuesday morning.
But the earliest Belfast International flight will not get her there on time.
"I had a transplant 15 months ago and these appointments are very important," she told BBC News.
"Now I have to go home and try to get in contact with the clinic to tell them that I am not going to be able to make it.
"That's a loss of an appointment not just for me, but someone else could have taken that appointment and I'm not going to be able to inform them because the clinic is closed today."
Risk that crew and pilots run out of time to fly - travel journalist
BBC 5 Live have been speaking to the Times' travel correspondent Ben Clatworthy.
He says that aviation analyst Cirium estimate that
around 3,000 flights are due to land in the UK today.
"Some of those will be
unaffected from earlier this morning but there will be thousands of flights who
are waiting to board aircraft," he adds.
Clatworthy also explains that "delays will likely build throughout the day" - adding that when "things start moving, one of the biggest risks still is that crew and
pilots run out of hours... and are unable to fly".
'My manager is really angry'
David Brooks, from south London, was sitting on an EasyJet plane for more than three hours before being told to disembark.
"We’re being given our
bags back… but we’ve not been told anything about when a flight might be.
"There’s no helpdesk for EasyJet at Valencia. But other staff told me the
flight won’t be today."
He has a four-year-old who he hasn't been able to feed since being put on the plane and disembarked, and says he's concerned about the potential repercussions for his job if he can't get back.
"I’ve got work
tomorrow, my manager is really angry... He didn’t believe me at first until I
told him to watch the news."
Comedian Paul Foot stuck in Edinburgh after festival
Getty ImagesCopyright: Getty Images
Comedian Paul Foot is trying to get back to London from the Edinburgh Fringe Festival. Despite being stuck there, he has managed to retain his sense of humour.
He tells the BBC News channel that he had waited at the airport for "a few hours", before eventually being "thrown out and told in no uncertain terms to 'take our luggage off the carousel and get out'."
Foot has since booked himself into a hotel. And while British Airways tells him they will pay for all reasonable expenses, the comedian says: "I don't know what reasonable is."
BA have also offered passengers a meal at their expense, up to the value of £20 per person. Looking toward to dinner, Foot concedes: "It won't be the lobster."
At present, he says it is "impossible to tell" how long they will be there for, though a flight tomorrow evening is possible.
For now, Foot is considering how he might spend his hotel stay.
"There is a spa at this hotel, but we don't have any swimming trunks, and Edinburgh airport isn't really somewhere we can buy swimming trunks," he says
"Where do you by swimming trunks anywhere in Scotland in August or indeed at any time of the year? It's a bit of a problem."
Flights still affected despite fix, says Harper
An update from Transport Secretary Mark Harper now, who says that despite the technical issue being resolved "flights are still unfortunately affected".
Posting to X, formerly Twitter, he encourages "all passengers to read the UK Civil Aviation Authority's guidance and be aware of their rights when flights are delayed or cancelled".
A brief history of some of Nats' problems
It's not the first time National Air Traffic Services has been affected by an issue big enough to disrupt passenger flights, but it's certainly one of the more disruptive incidents in its history.
Here are some of the other times the Nats system has gone wrong:
July 2019 - more than 50 flights had to be cancelled at various London airports following an "issue with radar displays" at Swanwick - the main air traffic control centre near Southampton.
April 2018 - an overhaul of the system at Swanwick delayed flights by about 20 minutes for up to three weeks.
August 2017 - Thousands of passengers had their flights delayed because of high sickness rates at Nats in Swanwick, the Guardian reported.
October 2015 - Passengers in Scotland were delayed after Nats reported interference on radio frequencies used to speak to aircraft.
December 2014 - A technical fault led to 10,000 people being affected by delays at Heathrow with almost 40 flights cancelled.
December 2013 - Hundreds of flights were cancelled after a problem with Nats' internal telephone system.
July 2013 - a computer failure at Swanwick, which involved a "rogue" flight plan being set up, caused dozens of flights to be delayed.
September 2008 - nearly 100 flights were cancelled at Heathrow, Gatwick and Luton after a computer glitch at Swanwick.
NatsCopyright: Nats
Passenger rebooks flight - 'but that is going to be delayed, isn't it?'
Lawrence Sinclair was due to fly with British Airways to Gothenburg, Sweden, just before 16:00 BST today.
He booked on a different flight at 20:50 BST after the first was cancelled.
"I don't know if the later flight is going to go or not," the 26-year-old tells the PA news agency.
"Hopefully I will fly at 8.50pm but that is going to be delayed, isn't it. It's annoying, I'm going to see my girlfriend in Sweden, but if I don't go today I'll go tomorrow."
Washington Post journalist covering 'Nessie hunt' stuck in Inverness
ReutersCopyright: Reuters
Boats souring the water for the Loch Ness monster over the weekendImage caption: Boats souring the water for the Loch Ness monster over the weekend
A journalist says she has been left stuck at Inverness airport after reporting on a mass search for the Loch Ness Monster over the weekend.
But there was no sign of Nessie over the weekend and now no sign of a flight back to Luton for Ms Hassan after spending more than six hours at the airport.
"As
time goes on you know people are getting more and more frustrated especially given
that many of us don’t actually know if we’ll even be booked onto another flight
today," she said.
"We’ve obviously missed our slot to fly out of Inverness now
and I’m sure there’s going to be a pretty big backlog of flights so it could be
a long wait."
'We have no idea if there’s any chance of us getting back to the UK'
Barbara has been especially unlucky with her UK-bound flight from Sardinia.
Accompanied by her six-year-old, she tells BBC Radio 5 Live the pair were due to fly home yesterday, but a problem with the aircraft meant EasyJet had to put them up in a hotel overnight.
The replacement flight was set to take off today at 11:30 local time - "and that's when everything hit" UK air traffic control operations, she says.
Three hours later, Barbara and her fellow passengers were still stuck on the tarmac. "We have been fed and watered - but it’s
airline food, so the kids are eating crisps and chocolate," she adds.
"There’s loads of children on the plane
because of the school holidays, we still have no idea if there’s any chance of
us getting back to the UK right now," Barbara says.
"The
staff on the plane have been great." But, Barbara tells our colleagues, one of the pilots said in 20 years in the job "he has
never experienced anything like this."
Live Reporting
Edited by Rob Corp
All times stated are UK
PA MediaCopyright: PA Media 
EPACopyright: EPA -
The "technical issues" that emerged around noon were "identified and remedied" by mid-afternoon
-
But today's flight delays and cancellations promise knock-on effects for days to come, with passengers telling the BBC they may not be able to return home until later this week
-
Others tell us they are seeking alternative routes home, ditching the planes for journeys by road and rail
-
British Airways, Jet2.com, Ryanair, EasyJet, Wizz Air, Loganair and Aer Lingus in turn issued statements apologising for the inconvenience, careful to make the point that the disruption was out of their control
-
Aviation analysts Cirium estimate that more than 500 flights into and out of the UK were cancelled as of 14:30 BST
- Transport Secretary Mark Harper said a short while earlier that flights were still "unfortunately affected", casting doubt over travel plans for the rest of the week
PA - Rory DollardCopyright: PA - Rory Dollard Rory Dollard's wife Joanne, and children Emily, 10, and Arthur, eight, waiting for updates at Bergerac Dordogne Perigord AirportImage caption: Rory Dollard's wife Joanne, and children Emily, 10, and Arthur, eight, waiting for updates at Bergerac Dordogne Perigord Airport 
Getty ImagesCopyright: Getty Images - Nats released a statement shortly after midday saying there was a problem which meant they were having to limit the number of aircraft they could handle
-
Airlines and airports began warning of lengthening delays and advising passengers to check the latest information before heading out
-
The BBC began receiving reports from passengers - especially those overseas - who were either facing long waits or having their return flights cancelled.
-
Just after 15:30 BST, UK air traffic control service Nats announced it had "identified and remedied the technical issue"
-
But the promising news was tempered by Transport Secretary Mark Harper, who said that despite fix, flights were still "unfortunately affected"
- Delays and cancellations ensued, with British Airways advising short-haul passengers not to travel to the airport unless their flight is shown to be operating
-
We've heard from many frustrated passengers across the day, including one mother who, accompanied by her six-year-old, had faced two flight cancellations in two days
-
And another woman told us she had missed a heart transplant check-up after her flight was cancelled from Belfast Airport
PA MediaCopyright: PA Media 
Getty ImagesCopyright: Getty Images - July 2019 - more than 50 flights had to be cancelled at various London airports following an "issue with radar displays" at Swanwick - the main air traffic control centre near Southampton.
- April 2018 - an overhaul of the system at Swanwick delayed flights by about 20 minutes for up to three weeks.
- August 2017 - Thousands of passengers had their flights delayed because of high sickness rates at Nats in Swanwick, the Guardian reported.
- October 2015 - Passengers in Scotland were delayed after Nats reported interference on radio frequencies used to speak to aircraft.
- December 2014 - A technical fault led to 10,000 people being affected by delays at Heathrow with almost 40 flights cancelled.
- December 2013 - Hundreds of flights were cancelled after a problem with Nats' internal telephone system.
- July 2013 - a computer failure at Swanwick, which involved a "rogue" flight plan being set up, caused dozens of flights to be delayed.
- September 2008 - nearly 100 flights were cancelled at Heathrow, Gatwick and Luton after a computer glitch at Swanwick.
NatsCopyright: Nats 
ReutersCopyright: Reuters Boats souring the water for the Loch Ness monster over the weekendImage caption: Boats souring the water for the Loch Ness monster over the weekend
Latest PostGoodbye
Emily Atkinson
Live reporter
The technical issues that sent UK air traffic control into meltdown earlier today have been resolved.
But with tales of delays and cancellations reaching us from the UK, mainland Europe and beyond, the impact of the hours-long outage seem far from over.
We will, of course, follow closely the fallout in the coming hours as well as hopefully get a greater understanding of what went wrong. In the meantime, you can keep an eye on the latest developments in our story here.
And for those of you with whose flights are affected, here's a guide to your rights.
For now, that's it from us in London. Today's writers were Thomas Mackintosh, Antoinette Radford, Ali Abbas Ahmadi, Emily Atkinson and Krystyna Gajda. The editors during the course of the day were Dulcie Lee, James Fitzgerald, Rob Corp and Heather Sharp.
The story of the day
So, air traffic control service Nats is now promising to investigate "very thoroughly" what caused the four-hour outage which has had such a huge impact on air travel today. We're wrapping things up here at London Broadcasting House. In the meantime, here's a recap of the key developments:
We will continue to cover this story as it develops in the coming hours and days.
As a reminder, if you have been badly affected by these events, we would be keen to hear from you. Get in touch by emailing haveyoursay@bbc.co.uk
'Quite a rare event' - air traffic control expert
Air traffic control expert Doug Maclean, who has nearly 40 years' experience, has been speaking to the BBC about what went wrong.
"The flight data processing system is really vital to running the volumes of air traffic that go through UK and European airspace," he says.
"When a plane is coming from say Milan to London, all the air traffic control centres will receive the flight plan from the plane. As it gets airborne, it'll be updated on the way".
It's when it breaks down, that you have to put the details in of every flight by hand.
"It's now become quite a rare event," he says.
"Dare I say it - probably 10 or 15 years ago, it was much more common."
Travel alternatives are 'tripling in price'
Carl is a teacher who is trying to get to Heathrow from Munich.
His original flight was cancelled and the earliest flight to Heathrow is on Thursday.
He’s told BBC News he's now travelling to Amsterdam to get a flight back to the UK on Wednesday.
"People are trying all sorts of routes - watching flights, ferry tickets and Eurostar tickets disappear in front of your eyes, or tripling in price is stressful," he says.
"I am trying to get home to prep for teaching next week. I'm losing two days work now and all my relaxation has gone."
Who pays for a hotel if you're stranded?
A British journalist who faces being stuck in France for up to six days is concerned about the uncertainty over who will pay for an extended stay following today's airline disruption.
Rory Dollard, cricket correspondent at PA Media, says he and other passengers stuck at Bergerac Dordogne Perigord Airport have heard "absolutely nothing" after the technical fault at air traffic control meant Ryanair could not bring them back to the UK.
He says he's been told it may take up to six days before he and his wife and two children can get home.
"I've never been in a situation like this before, and because of the language barrier, it's hard to work out exactly who's responsible for which part of the cost," he says.
"If you need to find a hotel for the next five or six nights, who's paying for this? Is it Ryanair? Is it your insurer? Is it somebody else?"
Stranded couple consider returning to Stuttgart by train
One stranded couple are considering returning home to Stuttgart by train after their flight from London was cancelled.
Myria Mebold, 36, also tells the PA news agency that British Airways "didn't know anything at all" when she and her husband asked about the situation and their flight.
"We are waiting for any information and checking if we can go back by train or anything, I don't know. Somehow we have to get back home."
When she asked BA staff for help, Mebold said they told her to come back at 6pm and "maybe then they can give more information."
"It was a nice day in London but now it is starting to get annoying."
She said the flight had been delayed to leave the UK after 1am on Tuesday, but planes cannot land at Stuttgart during the night.
We will be investigating very thoroughly - Nats
UK air traffic control service Nats has posted a video message on social media, apologising for the impact on people's travel plans.
Its operations director, Juliet Kennedy, explains "the automatic system, which provides controllers with details of every aircraft and its route wasn't working" and "instead to manage safety we had to limit the number of flights we could manage".
She says Nats' teams "worked hard to resolve the problem" but "it will take some time for flights to return to normal".
"We will continue to work with the airlines and airports to recover the situation," she says.
"Our absolute priority is safety and we will be investigating very thoroughly what happened today," Kennedy adds.
Malaga Airport 'out of beer'
A concerning update now from Malaga Airport.
Facing a delay of "many hours" at the terminal, BBC Radio 1 presenter Jordan North says the airport bar has run out of beer.
We are duty-bound to remind anyone reading this page that while there is no specific limit on how much you can drink on a flight, it is a criminal offence in the UK to be drunk on board an aircraft.
Where are we up to?
We launched our live coverage of the "technical issues" affecting UK air traffic control just after midday. More than seven hours in and, while delays are continuing, the actual cause of the disruption has been fixed.
A lot has happened so here's a reminder of the key developments:
We'll continue our rolling coverage for a while longer, as well as updating our main news story.
Jet2 cancels some outbound flights and warns of 'significant delays'
An update now from UK holiday airline Jet2.com, which says it has taken the decision to cancel some outbound flights today.
In a newly updated statement, the carrier also warns of "significant delays" ahead for passengers travelling to and from the UK.
"Our teams are working incredibly hard to communicate with, and look after, our customers and they will continue to do so," it adds.
Jet2.com says it will be contacting all affected customers to let them know. Affected passengers will also receive a full refund.
"We are extremely sorry to have to take this decision however the ATC disruption leaves us with no other choice."
The airline says it is reviewing Tuesday's flights and will update customers in due course.
"Customers due to travel tomorrow should travel to the airport as normal unless we advise otherwise, and continue to monitor Flight Information on our website," the statement continues.
"We would of course like to apologise to everyone that is affected by this situation, which is unfortunately completely outside of our control."
'EasyJet have been poor'
Richard Ockenden and his family, from Preston, were due to travel back from Lisbon to Manchester this evening.
Like many others, their EasyJet flight was cancelled.
The family are now driving north through Portugal to Porto where their return flight is scheduled for 9pm tomorrow, while trying to arrange accommodation for the night ahead.
"There has been no communication from [EasyJet] beyond notifications on their app," Richard tells the BBC. "The app offers to find you accommodation but there is nothing available.
"EasyJet have been poor," he adds.
"All this with a very tired one year old and an excited five year old as we get an 'extra day' of holiday."
In a statement shared earlier, EasyJet said: "While these circumstances are outside of our control, we would like to apologise for the inconvenience caused and to reassure customers that we are doing everything possible to minimise the impact of the disruption."
Woman misses heart transplant check-up over flight delay
A woman from Northern Ireland has told the BBC today's disruption means she is likely to miss an appointment in England for a check-up following a heart transplant after her flight was cancelled earlier.
Serena Hamilton, from Cookstown, is expected at the Freeman Hospital in Newcastle-upon-Tyne on Tuesday morning.
But the earliest Belfast International flight will not get her there on time.
"I had a transplant 15 months ago and these appointments are very important," she told BBC News.
"Now I have to go home and try to get in contact with the clinic to tell them that I am not going to be able to make it.
"That's a loss of an appointment not just for me, but someone else could have taken that appointment and I'm not going to be able to inform them because the clinic is closed today."
Risk that crew and pilots run out of time to fly - travel journalist
BBC 5 Live have been speaking to the Times' travel correspondent Ben Clatworthy.
He says that aviation analyst Cirium estimate that around 3,000 flights are due to land in the UK today.
"Some of those will be unaffected from earlier this morning but there will be thousands of flights who are waiting to board aircraft," he adds.
Clatworthy also explains that "delays will likely build throughout the day" - adding that when "things start moving, one of the biggest risks still is that crew and pilots run out of hours... and are unable to fly".
'My manager is really angry'
David Brooks, from south London, was sitting on an EasyJet plane for more than three hours before being told to disembark.
"We’re being given our bags back… but we’ve not been told anything about when a flight might be.
"There’s no helpdesk for EasyJet at Valencia. But other staff told me the flight won’t be today."
He has a four-year-old who he hasn't been able to feed since being put on the plane and disembarked, and says he's concerned about the potential repercussions for his job if he can't get back.
"I’ve got work tomorrow, my manager is really angry... He didn’t believe me at first until I told him to watch the news."
Comedian Paul Foot stuck in Edinburgh after festival
Comedian Paul Foot is trying to get back to London from the Edinburgh Fringe Festival. Despite being stuck there, he has managed to retain his sense of humour.
He tells the BBC News channel that he had waited at the airport for "a few hours", before eventually being "thrown out and told in no uncertain terms to 'take our luggage off the carousel and get out'."
Foot has since booked himself into a hotel. And while British Airways tells him they will pay for all reasonable expenses, the comedian says: "I don't know what reasonable is."
BA have also offered passengers a meal at their expense, up to the value of £20 per person. Looking toward to dinner, Foot concedes: "It won't be the lobster."
At present, he says it is "impossible to tell" how long they will be there for, though a flight tomorrow evening is possible.
For now, Foot is considering how he might spend his hotel stay.
"There is a spa at this hotel, but we don't have any swimming trunks, and Edinburgh airport isn't really somewhere we can buy swimming trunks," he says
"Where do you by swimming trunks anywhere in Scotland in August or indeed at any time of the year? It's a bit of a problem."
Flights still affected despite fix, says Harper
An update from Transport Secretary Mark Harper now, who says that despite the technical issue being resolved "flights are still unfortunately affected".
Posting to X, formerly Twitter, he encourages "all passengers to read the UK Civil Aviation Authority's guidance and be aware of their rights when flights are delayed or cancelled".
A brief history of some of Nats' problems
It's not the first time National Air Traffic Services has been affected by an issue big enough to disrupt passenger flights, but it's certainly one of the more disruptive incidents in its history.
Here are some of the other times the Nats system has gone wrong:
Passenger rebooks flight - 'but that is going to be delayed, isn't it?'
Lawrence Sinclair was due to fly with British Airways to Gothenburg, Sweden, just before 16:00 BST today.
He booked on a different flight at 20:50 BST after the first was cancelled.
"I don't know if the later flight is going to go or not," the 26-year-old tells the PA news agency.
"Hopefully I will fly at 8.50pm but that is going to be delayed, isn't it. It's annoying, I'm going to see my girlfriend in Sweden, but if I don't go today I'll go tomorrow."
Washington Post journalist covering 'Nessie hunt' stuck in Inverness
A journalist says she has been left stuck at Inverness airport after reporting on a mass search for the Loch Ness Monster over the weekend.
Jennifer Hassan, a London-based reporter for the Washington Post, joined a group of about 200 volunteers who were seeking to find a glimpse of the mythical monster.
But there was no sign of Nessie over the weekend and now no sign of a flight back to Luton for Ms Hassan after spending more than six hours at the airport.
"As time goes on you know people are getting more and more frustrated especially given that many of us don’t actually know if we’ll even be booked onto another flight today," she said.
"We’ve obviously missed our slot to fly out of Inverness now and I’m sure there’s going to be a pretty big backlog of flights so it could be a long wait."
'We have no idea if there’s any chance of us getting back to the UK'
Barbara has been especially unlucky with her UK-bound flight from Sardinia.
Accompanied by her six-year-old, she tells BBC Radio 5 Live the pair were due to fly home yesterday, but a problem with the aircraft meant EasyJet had to put them up in a hotel overnight.
The replacement flight was set to take off today at 11:30 local time - "and that's when everything hit" UK air traffic control operations, she says.
Three hours later, Barbara and her fellow passengers were still stuck on the tarmac. "We have been fed and watered - but it’s airline food, so the kids are eating crisps and chocolate," she adds.
"There’s loads of children on the plane because of the school holidays, we still have no idea if there’s any chance of us getting back to the UK right now," Barbara says.
"The staff on the plane have been great." But, Barbara tells our colleagues, one of the pilots said in 20 years in the job "he has never experienced anything like this."