Passengers are facing another day of disruption at London Heathrow after an alleged cyber attack targeted a service provider for check-in and boarding systems.
Heathrow, Brussels and Berlin airports all experienced delays and disruption on Saturday following the “technical issue” affecting Collins Aerospace, which works for several airlines at multiple airports across the world.
The disruption began on Friday night and continued throughout Saturday, with flights cancelled or delayed as the impacted airlines had to carry out check-in and boarding operations manually.
Passengers due to fly from the airport’s Terminal 4 said they were met with queues, delays and confusion as to whether they’d be able to make their planned trips.
Heathrow said on Saturday passengers should check their flight status before travelling to the west London airport.
Questions are now being asked as to what caused the global IT meltdown, with politicians and aviation experts appearing to point the finger at the Kremlin.
Scroll down for the latest updates.
Key Points
- Heathrow urges passengers to check flights as check-in system hit by outage
- 129 Heathrow flights delayed today, live data shows
- Collins Aerospace confirms ‘cyber-related disruption’ hitting Heathrow flights
Cyber issue 'resolved' on BA flights
19:30 , Bill BowkettThe issue made aware earlier has now been resolved. London Heathrow is also able to assist with completing online check-in. Oliver
— British Airways (@British_Airways) September 21, 2025
Passengers facing another day of disruption after check-in system ‘cyber attack’
18:31 , Bill Bowkett
Passengers facing another day of disruption after check-in system ‘cyber attack’
Disruption ongoing at Dublin
17:26 , Bill Bowkett
Disruption is ongoing at Dublin Airport following the alleged cyber attack, as well as a separate security incident.
Some 13 flights, nine inbound and four outbound, had been cancelled by 12pm on Sunday.
600 Heathrow flights disrupted on Saturday
16:24 , Bill BowkettA total of 629 flights from London Heathrow Airport were disrupted by the cyber attack on Saturday, according to FlightRadar data.
The total has climbed so far on Sunday, with the website reporting 233 delayed flights.
'Half of flights cancelled from Brussels'
15:27 , Bill Bowkett
Brussels Airport has requested airlines cancel half of their departing passenger flights until 4am on Monday due to issues with its check-in system.
A spokesman for air traffic controller Skeyes said Collins Aerospace has yet to deliver a secure updated version of the software necessary to restore full functionality.
'Cyber attack’ latest in series of incidents at Heathrow
14:46 , Bill Bowkett
On March 21, more than 270,000 air passenger journeys were disrupted by Heathrow airport’s closure following a fire at a nearby electrical substation.
Some 234,000 passengers booked to fly to or from Heathrow that day had their flight cancelled, diverted or delayed when the airport suffered a power outage because of a blaze at the substation in Hayes, aviation industry statistics have showed.
No flights were permitted at the airport on that day until around 6pm.
A further 36,500 people hoping to travel the following day were affected when 74 flights, 6.1% of the total scheduled, were cancelled.
Heathrow passengers still face some disruption with flights cancelled and delayed
13:29 , Sami QuadriPassengers at Heathrow are still experiencing some disruption on Sunday afternoon.
Around seven departing flights have been cancelled and 18 others delayed, according to the PA news agency. It is not yet clear which of these are linked to the recent technical issue affecting check-in systems.
British Airways flights at Heathrow Terminal 5 ‘operating as normal’
12:17 , Sami QuadriIt is understood that British Airways services at Heathrow Terminal 5 remain unaffected by the cyber attack.
The airline has been operating as normal throughout the disruption, which has caused delays and cancellations for other carriers across Heathrow and several major European airports.
Brussels, Berlin and Heathrow passengers still facing delays on Sunday
12:07 , Sami QuadriMany passengers are still experiencing delays on Sunday as airlines work to deal with the fallout from Friday’s cyber attack.
At Brussels Airport, data from FlightRadar24 shows travellers are facing average delays of around 53 minutes.
In Berlin, the average delay is around 30 minutes, while at Heathrow passengers are waiting roughly 27 minutes on average.
It is not yet clear how many of these delays are directly linked to the cyber attack.
Heathrow cyber attack a ‘prime example’ of aviation supply chain risks, expert warns
10:51 , Sami QuadriCybersecurity expert Vykintas Maknickas, CEO of NordVPN’s travel eSIM app Saily, said Friday’s cyber attack is a “prime example” of the risks facing the aviation industry due to its heavy reliance on digital systems.
“This recent cyberattack highlights the increasing vulnerabilities within the aviation sector as airports and airlines continue to rely on interconnected systems for operations,” he said.
“As we've seen with the disruptions at major airports, the impact of a cyberattack on critical infrastructure can be profound, affecting everything from check-ins to baggage handling.”
Maknickas said the incident underlined the supply chain risks that make airports more vulnerable to widespread disruption.
“Many airports, including those affected in this incident, rely on the same third-party systems for passenger handling. While this approach boosts operational efficiency, it significantly reduces resilience,” he explained.
“A single cyberattack on one vendor can quickly escalate into widespread disruptions across multiple airports, as seen with the delays and cancellations at major European hubs like Heathrow, Brussels, and Berlin.”
40 flights delayed at Heathrow so far today, live data shows
09:31 , Sami QuadriA total of 40 flights have been delayed at London Heathrow so far today, according to live data from flight-tracking service FlightAware.
The delays come as Heathrow and several other European airports continue to recover from a cyber attack on Collins Aerospace, which disrupted check-in and boarding systems on Friday and Saturday.
Heathrow has said the “vast majority” of flights are operating but urged passengers to check the status of their flight before travelling and to arrive no earlier than three hours before long-haul departures and two hours before short-haul.
We’ll continue to monitor FlightAware data for updated figures throughout the day.
Brussels Airport warns of delays and cancellations amid cyber attack
09:18 , Sami QuadriBrussels Airport said on Sunday: “As a result of a cyberattack on the external service provider of the check-in and boarding systems, check-in operations at several European airports, including Brussels Airport, are heavily disrupted.
“The service provider is actively working on the issue and trying to resolve the problem as quickly as possible.
“This has a large impact on the flight schedule and will, unfortunately, cause delays and cancellations of flights.”
Heathrow says ‘vast majority’ of flights still operating despite outage
08:29 , Sami QuadriWork continues to resolve and recover from Friday's outage of a Collins Aerospace airline system that impacted check-in. We apologise to those who have faced delays, but by working together with airlines, the vast majority of flights have continued to operate.
— Heathrow Airport (@HeathrowAirport) September 20, 2025
We encourage… pic.twitter.com/Y5YNCiOrk2
European Commission is 'closely monitoring' cyber attack
08:00 , Sami QuadriThe European Commission, which takes part in managing airspace across Europe, said it is monitoring the situation but added there were no signs the alleged cyber attack was “widespread or severe”.
A spokesperson for the European Commission said on Saturday evening: “The commission is closely monitoring the cyber attack that has disrupted airline check-in and boarding systems for several airlines across multiple airports globally.
“While passengers are facing disruption, aviation safety and air traffic control remain unaffected.
“The commission is working closely with EUROCONTROL, ENISA, airports and airlines to restore operations and to support passengers.
“Current signs do not indicate a widespread or severe attack.”
Lib Dems demand probe into possible Russian link to Heathrow cyber attack
07:22 , Sami QuadriThe Government must urgently confirm whether Russian involvement is suspected in the alleged cyber attack on an airport check-in provider, the Liberal Democrats have said.
Lib Dem foreign affairs spokesperson Calum Miller said: “After the flagrant violation of Estonian airspace, the Government needs to urgently establish if Vladimir Putin is now attacking our cyber systems.
“If the Kremlin is behind this attack, causing chaos at our busiest airport, we need to be firm in our response.”
Airport disruption 'could last for days'
Saturday 20 September 2025 19:39 , Bill BowkettAdrianus Warmenhoven, a cybersecurity expert at NordVPN, told The Sun: "Even though airports are switching to manual check-ins, that’s a slow and clunky process compared to automated systems.
"The backlog of delayed flights, stranded crews and missed connections will take time to clear, so passengers should expect disruption well into the weekend.
"For a hub like Heathrow, even a few hours offline can ripple through the entire weekend’s schedule."
Get in touch
Saturday 20 September 2025 18:42 , Bill BowkettHave you been affected by the cyber attack causing major delays at Heathrow or Europe's major airports? Please email bill.bowkett@standard.co.uk.
EU say no evidence of 'widespread or severe attack'
Saturday 20 September 2025 17:43 , Bill BowkettA spokesman for the European Commission said there is no evidence of a "widespread or severe attack” relating to the cyber attack affecting several European airports, including Heathrow.
Brussels officials added that the origin of the incident was still under investigation.
Lib Dems question Russian involvement
Saturday 20 September 2025 16:59 , Bill BowkettThe Liberal Democrats have urged officials to determine whether the Kremlin is behind the cyber-attack after three Russian military jets violated Estonia’s airspace for 12 minutes on Friday.
A party spokesman said: “After the flagrant violation of Estonian airspace, the Government needs to urgently establish if Vladimir Putin is now attacking our cyber systems.
“If the Kremlin is behind this attack, causing chaos at our busiest airport, we need to be firm in our response.”
National Cyber Security Centre investigating
Saturday 20 September 2025 16:14 , Bill BowkettThe National Cyber Security Centre, part of GCHQ, is currently “working with Collins Aerospace and affected UK airports, alongside Department for Transport and law enforcement colleagues, to fully understand the impact of an incident”.
A spokesman added: “All organisations are urged to make use of the NCSC’s free guidance, services and tools to help reduce the chances of a cyber attack and bolster their resilience in the face of online threats.”
Heathrow passenger ‘in tears’ after being shouted at amid long queues
Saturday 20 September 2025 15:19 , Sami QuadriA passenger said she “broke down in tears” after being shouted at by staff at Heathrow Airport amid long queues.
Helen Steel, 49, who was trying to fly home with KLM to Oslo via Amsterdam with a cat named Thomas, said her experience at the airport had been an “absolute nightmare”.
Speaking at a crowded Terminal 4, Ms Steel told the PA news agency: “I started travelling this morning at 3am from Dorset, and they knew about the cyber attack yesterday and didn’t tell us.
“If they just told us that there was a cyber attack, I wouldn’t have travelled up here.
“I’ve got an animal here, so I’m very concerned about his welfare.
“I’ve been shouted at twice and I broke down in tears because I was worried about him.
“None of us have had any information whatsoever. Whenever we ask ground staff, they shout at us.
“They tell us to call customer service – I’ve spent about two hours in a queue on the telephone. I then finally got through to somebody and they put the phone down on me.
“It’s another three hours to get back home and then come back up again if they find a new flight, so now I must go look for a hotel, but I’m still stuck in this queue.”
Brussels Airport confirms that 14 flights have been cancelled
Saturday 20 September 2025 14:13 , Sami QuadriBrussels Airport has confirmed that 14 flights have been cancelled so far today, an increase from 10 earlier in the day.
The airport said departing flights are now facing average delays of around one hour.
It is urging passengers to travel to the airport only after checking with their airline that their flight is still scheduled to operate.
Pictured: Travellers face long queues at Heathrow following cyber attack
Saturday 20 September 2025 13:56 , Sami Quadri
German airport says it's 'only indirectly affected' by cyber attack
Saturday 20 September 2025 13:06 , Sami QuadriMünster/Osnabrück Airport in northeast Germany has said it was “only indirectly affected” by the cyber attack impacting airports across Europe.
In a statement, the airport described the incident as a “technical malfunction” and outlined the steps taken to keep flights running on time.
“Munster/Osnabruck Airport was only indirectly affected by the technical malfunction of the external system provider,” it said.
“As a preventive measure, we have redirected our handling systems to our internal IT infrastructure, ensuring a smooth operational process for arrivals and departures.
“As of now, operations are running without restrictions, and all flights were able to depart from FMO on schedule last night.”
Heathrow cyber attack shows ‘supply chain vulnerabilities’, expert warns
Saturday 20 September 2025 12:49 , Sami QuadriRob Jardin, Chief Digital Officer at cybersecurity firm NymVPN, said the cyber attack affecting Heathrow and other European airports underlined the risks of relying on third-party suppliers.
“The cyberattack on Heathrow and other European airports is the latest in a spate of incidents this year, and it shows just how vulnerable our critical infrastructure is when reliant on third-party suppliers,” he said.
“Even if the airport’s own systems aren’t breached, an attack on a partner can still bring flights to a standstill.
“Increasingly, hackers are not just criminals but are being weaponised by hostile nation states against Europe, with supply chains seen as an easy way to cause chaos.
“We’ve seen this pattern before in retail, automotive, and now aviation – criminals are deliberately targeting supply chains to cause maximum disruption. For passengers, it means delays; for businesses, it’s lost money and far more importantly, shaken confidence.
“The lesson is clear – security can’t stop at your own network. Every supplier must meet the same high standards, and we need more resilient, decentralised infrastructures so that a single point of failure can’t paralyse critical services.
“Strong encryption, regular audits, and contingency planning are now essential to stop today’s disruption becoming tomorrow’s norm.”
Heathrow passenger faces three-hour queue as cyber attack hits check-in
Saturday 20 September 2025 12:32 , Sami QuadriMaria Casey, from Aldershot in Hampshire, was on her way to a two-week backpacking holiday in Krabi, southern Thailand, via Abu Dhabi.
But her Etihad flight departing at 9.30am from Heathrow Airport’s Terminal 4 was delayed and she ended up queuing for three hours as baggage check-in had to be done manually.
“They had to write our baggage tabs by hand,” she told the PA news agency.
“Only two desks were staffed, which is why we were cheesed off.
“Didn’t know then it was a cyber attack until four hours later.
She added: “Just got to go with the flow”.
Pictured: People queue at Heathrow after check-in system cyber attack
Saturday 20 September 2025 11:36 , Sami Quadri
Transport Secretary urges Heathrow passengers to check flight status amid delays
Saturday 20 September 2025 11:24 , Sami QuadriI'm aware of an incident affecting airline check-in and boarding, impacting flights at Heathrow and other European airports.
— Heidi Alexander MP (@Heidi_Labour) September 20, 2025
I’m getting regular updates, and monitoring the situation. If you’re flying at Heathrow today, check with your airline before travelling. https://t.co/DbcWPZZXLO
Passenger describes ‘insane’ Heathrow queues after global check-in outage
Saturday 20 September 2025 11:18 , Sami QuadriFreelance journalist Tereza Pultarova, from London, arrived at Heathrow Airport in the early hours of Saturday morning to catch a KLM Royal Dutch Airlines flight to Amsterdam, where she was due to connect to Cape Town, South Africa.
But instead of a smooth departure, she was met with queues, delays and confusion about whether she would make her trip at all.
She told the PA news agency: “We’ve been here since 4.30am — we were supposed to be on a 6.30am flight to Amsterdam.
“Most people on this flight have connecting flights to catch in Amsterdam from all over the world.
“We were kind of stranded here because the weird thing is, KLM wasn’t able to issue us boarding passes digitally, and requested us to collect them at the check-in desk.
“And then they told us that there is some sort of global issue with the system they’re using for check-in and boarding, and they have to do everything manually.
“So then they were checking in people at the rate of, like, one person per 10 minutes.
“I’m not exaggerating. It was just insane, the queue wasn’t moving.
“And then suddenly they said, ‘Oh, the flight will be departing, we’re closing the gate’.
“So they checked-in like 20 people, maybe like the business class, and then told the people from the 6.30 flight to just go away, that they need to start checking in for the 8.40 flight.”
Ms Pultarova had been due to visit the Square Kilometre Array telescopes in the Karoo Desert for work, a trip she had been anticipating for months.
“I need to be there at 7am tomorrow, otherwise the party will leave for the Karoo Desert where the telescopes are.
“So yeah, you know, I need to have information, but nobody’s giving me any information, so I don’t know what to do.”
Eventually, Ms Pultarova was told she could take a 3.30pm flight — but this meant she would miss her Amsterdam connection.
129 Heathrow flights delayed today, live data shows
Saturday 20 September 2025 10:47 , Sami QuadriA total of 129 flights have been delayed at London Heathrow so far today, according to live data from flight-tracking website FlightAware.
The delays follow a “cyber-related disruption” at Collins Aerospace, which provides check-in and boarding systems to airlines worldwide. The outage has forced staff at multiple airports to carry out manual check-in procedures, leading to queues and slower boarding.
Heathrow has urged passengers to check the status of their flight before travelling and to arrive no earlier than three hours before a long-haul flight or two hours before a domestic service.
What is Collins Aerospace?
Saturday 20 September 2025 10:32 , Sami QuadriCollins Aerospace is a US-based aviation and defence company that supplies technology to airlines and airports worldwide. It is part of RTX Corporation (formerly Raytheon Technologies).
One of its key products, ARINC cMUSE, is a common-use passenger processing system that powers check-in desks, boarding gates and baggage drop operations at many airports.
Today, Collins Aerospace confirmed it is dealing with a “cyber-related disruption” affecting its systems at “select airports.” The issue is impacting electronic check-in and baggage drop, forcing staff to switch to manual procedures.
This has led to longer queues and flight delays at Heathrow, Brussels and Berlin airports.
Collins Aerospace confirms ‘cyber-related disruption’ hitting Heathrow flights
Saturday 20 September 2025 10:10 , Sami QuadriA service provider for check-in and boarding systems has said it is working to resolve technical issues following a “cyber-related disruption” causing delays and cancellations at airports in the UK and Europe.
The disruption is affecting flights at Heathrow, Berlin, and Brussels airports.
Collins Aerospace said on Saturday: “We have become aware of a cyber-related disruption to our Muse software in select airports.
“We are actively working to resolve the issue and restore full functionality to our customers as quickly as possible.
“The impact is limited to electronic customer check-in and baggage drop and can be mitigated with manual check-in operations.
“We will share more details as they are available.”
Heathrow departure delays now averaging 31 minutes, data shows
Saturday 20 September 2025 09:52 , Sami QuadriFlights departing from Heathrow are now facing average delays of 31 minutes – and rising – according to live data from FlightAware.
The disruption comes after a cyber attack hit Collins Aerospace, the global provider of airline check-in and boarding systems. The outage has forced staff at multiple airports to switch to manual procedures, leading to longer queues and slower boarding times.
Heathrow has urged passengers to check the status of their flights before travelling to the airport and to arrive no earlier than three hours before a long-haul flight or two hours before a domestic service.
We’ll continue monitoring FlightAware for the latest delay statistics and bring you updates as the situation develops.
Heathrow urges passengers to check flights as check-in system hit by outage
Saturday 20 September 2025 09:46 , Sami QuadriHeathrow Airport said passengers should check their flight status before travelling to the west London airport after “a technical issue” affected a service provider for check-in and boarding systems.
In a statement, Heathrow said: “Collins Aerospace, which provides check-in and boarding systems for several airlines across multiple airports globally, is experiencing a technical issue that may cause delays for departing passengers.
“While the provider works to resolve the problem quickly, we advise passengers to check their flight status with their airline before travelling.
“Please arrive no earlier than three hours before a long-haul flight or two hours before a domestic flight. Additional colleagues are available in check-in areas to assist and help minimise disruption.
“We apologise for any inconvenience.”
What we know so far about the cyber attack causing Heathrow delays
Saturday 20 September 2025 09:38 , Sami QuadriWelcome to our live coverage of disruption at Heathrow Airport after a cyber attack hit check-in systems across Europe.
Passengers at Heathrow are facing delays this afternoon after a “technical issue” at a third-party supplier caused widespread problems for airlines.
The disruption is being linked to a cyber attack targeting Collins Aerospace, a company that provides check-in and boarding systems to multiple airlines worldwide.
Brussels Airport has confirmed 10 flights have been cancelled and at least 17 are delayed by more than an hour. Staff have switched to manual check-in procedures, causing long queues.
“It is still too early to say when the problem will be resolved,” Brussels Airport said in a statement, warning of “a large impact” on flight schedules.
Berlin Airport is also experiencing delays, and London’s Heathrow has urged passengers to check flight statuses before travelling.
We’ll bring you updates on flight cancellations, statements from airports and tips for affected travellers as this story develops.
