By Mathilde Grandjean

Copyright standard

Passengers stranded at Heathrow have described the situation as “an absolute nightmare” after an alleged cyber attack caused major disruption at several European airports.

The alleged attack, which targeted a provider for check-in and boarding systems, caused significant technical issues at Heathrow, Berlin and Brussels airports, with many flights delayed or cancelled.

Helen Steel, 49, who was trying to fly home with KLM to Oslo via Amsterdam with a cat named Thomas, told the PA news agency she “broke down in tears” after being shouted at by staff at Heathrow Airport amid long queues.

Speaking at a crowded Terminal 4, Ms Steel said: “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.”

Long queues have formed at the check-in area of Heathrow Terminal 4.

While airport staff attempt to manage the snaking queues, many passengers have resorted to sitting on the floor with limited seats left in the crowded terminal.

Maria 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’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,” Ms Casey told PA.

“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.”

Tereza Pultarova, a freelance journalist from London, arrived at Heathrow in the early hours of the morning to catch a KLM Royal Dutch Airlines flight to Amsterdam, where she was to hop on a connection flight to Cape Town in South Africa.

“We’ve been here since 4.30am, we were supposed to be on a 6.30am flight to Amsterdam,” Ms Pultarova told PA.

“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 was to visit the Square Kilometre Array telescopes in the Karoo Desert for work, and added she had been looking forward to this trip for months.

She said: “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.”

Ms Pultarova was eventually told she could get on the 3.30pm flight – which means she will miss her connection flight in Amsterdam.

“It’s one of those things where you don’t have really flexibility,” she said.

“So for me, it’s really been a big bummer.”

Collins Aerospace, the supplier whose systems are affected, said it is working to resolve the issue as soon as possible.

“We have become aware of a cyber-related disruption to our Muse (multi-user system environment) software in select airports,” the provider said in a statement.

“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.”

Heathrow said passengers should check their flight status before travelling to the west London airport.

A National Cyber Security Centre (NCSC) spokesman said: “We are working with Collins Aerospace and affected UK airports, alongside Department for Transport and law enforcement colleagues, to fully understand the impact of an incident.

“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.”