Flight delays and cancellations are expected to continue at UK airports on Wednesday after another air traffic control failure kept planes grounded for hours, affecting hundreds of thousands of passengers.

Dublin Airport said airlines are operating a full schedule of flights on Wednesday following a “challenging day” on Tuesday, with about 90 flights to and from Dublin being cancelled.

Here’s everything you need to know if your flight is delayed or cancelled.

What happened with flights on Tuesday?

A “technical issue” at the air traffic control services provider Nats caused Britain’s third major stoppage in just over three years.

Nats provides air traffic control services to 15 UK airports. The breakdown started at about 1pm on Tuesday and affected departing flights at many of Britain’s biggest airports including Heathrow, Gatwick, Manchester and Stansted.

By the time Nats said it had fixed its flight processing system almost four hours later, most flights scheduled to depart were yet to take off.

Flights to and from other airports around the UK, including Edinburgh and Belfast, were also disrupted.

Cancellations and delays continued through Tuesday evening, and British Airways said disruption would affect operations into Wednesday at least, with passengers offered free rebooking until Friday.

What exactly is this “technical issue”?

Nats initially announced at 1.46pm on Tuesday that it was “investigating a technical issue which was causing some disruption to flight departures”. It later identified the problem in its flight processing system, and announced at 4.40pm that it was fixed.

A spokesperson said the fault was not the same as those that caused outages and mass disruption in 2023 and 2025. “We are continuing to work closely with our airline and airport customers on recovery. We apologise sincerely for the disruption to people’s journeys today and they should continue to check with their airline,” it said.

Further flight disruptions expected after UK air traffic control breakdown

The chief executive of Nats, Martin Rolfe, was scheduled to brief the UK transport secretary, Heidi Alexander, on Wednesday over the breakdown.

The air traffic control problems follow an “isolated event” a year ago that caused widespread disruption, and appeared less severe than the full grounding of flights in August 2023, which prompted a parliamentary inquiry.

Airlines have renewed calls for Nats to be overhauled.

So, what should I do?

The first thing is to keep in touch with your airline. It might also be worth keeping an eye on the airport’s live arrivals and departures pages as well as the airport you’re hoping to fly into.

Dublin Airport said airlines are operating a full schedule of flights on Wednesday but passengers should “keep in contact with their airline directly to get the latest updates on the status of their flight”.

The airport also said the “significant upheaval” on Tuesday means the possibility of some disruption across the wider flight network in Europe remains on Wednesday.

My flight has been cancelled. What are my rights?

Under EU Regulation 261 airlines are obliged to offer passengers affected by cancellations a full refund or a rerouting on the next available flight or at a later time that suits the passenger. If you opt for a refund, the airline’s responsibility to you ends there and then. If you ask to be put on the next available flight then the airline must provide care and assistance until you can be accommodated on an alternative flight.

Care and assistance? What does that actually mean?

If you are overseas and trying to get home, the airline must provide you with meals and refreshments. If necessary, it will have to cover the cost of hotel accommodation and transport between the hotel and the airport and you will have to be offered two free telephone calls and access to email.

There is no one from the airline at the airport and I can’t get through to their help desk. Who is going to give me money for the hotel? And indeed find me a hotel?

The days of airlines being on hand to ferry passengers facing cancellations to airport hotels have long gone in many instances, but that does not mean your rights are gone.

If you can’t make contact with the airline or it does not provide the care and assistance it is legally obliged to at the moment you need it, then you should make your own reasonable arrangements. It is to retain all receipts because you will need them to claim back the reasonable expenses.

Reasonable expenses? What does that mean?

The definition is pretty loose. If you check into a five-star hotel and eat and drink all around you at the fanciest of French restaurants while waiting to get home and then look to be reimbursed, you can expect to be disappointed. If you stay in a modestly priced hotel and eat in modestly priced restaurants while you are waiting for the problems to be resolved, then you will be able to claim that money back. Ultimately it is aviation regulators across the EU who decide what is reasonable.

How do I claim back expenses incurred?

Passengers should send copies (it is very important the original documentation is never sent in case it goes missing) of all receipts to the airlines on which they booked flights. Submissions should include booking references, passenger names, original and new flight details.

I don’t think my flight is going to be cancelled but it looks like it is being delayed. Do I have any rights in this case?

You do. If you are facing a delay, the airline must also provide you with care and assistance. If you are left hanging around in an airport it must cover reasonable cost of meals and refreshments. The point at which airlines must step in with help depends on the length of the journey. It should be after a two-hour delay on flights up to 1,500km, after three hours for flights of between 1,500km and 3,500km, and four hours on longer flights. If your flight is delayed by more than five hours, an airline must offer you the choice of continuing with your journey or a refund of the cost of your ticket.

Am I entitled to compensation outside of reasonable expenses from my airline?

That is most unlikely and we can’t stress that enough. The issue is likely to be considered an eventuality outside of the airline’s control, in which case compensation does not apply. We have heard of many instances where legitimate claims for expenses to be reimbursed are rejected by airlines because passengers mistakenly say they are looking for compensation.