BBCA fire close to Heathrow Airport has thrown flights to and from the London airport into chaos with flights from the island of Ireland being heavily impacted.
Heathrow Airport will be closed all day on Friday after a fire at a nearby electrical substation that supplies it with power.
At least 1,351 flights to and from UK’s busiest airport could be cancelled on Friday, according to flight tracking website Flightradar24.
Belfast City and City of Derry airports advised passengers due to fly to Heathrow not to travel to the airports and to contact their airlines.
A number of flights to and from Heathrow are showing as cancelled on Belfast City Airport’s website.
A Heathrow spokesperson said its terminals had to be shut as they “do not have clarity on when power may be reliably restored”.
The London Fire Brigade said the fire at the electricity substation in Hayes which led to the widespread disruption at Heathrow Airport – is now “under control”.
City of Derry Airport confirmed that all flights to Heathrow are cancelled on Friday.
“Passengers are advised not to travel to the airport but to contact their airline directly to make alternative arrangements,” a spokesperson said.
Belfast International Airport, which does not operate flights to Heathrow, has said it is so far operating as normal.
Irish broadcaster RTÉ have reported that 70 flights between Ireland and Heathrow have been affected by the fire.
All flights scheduled between Dublin Airport and London Heathrow on Friday have also been cancelled.
In a post on social media, the airport said further disruption to flights between Dublin and Heathrow over the coming days is possible.
A total of 34 flights were scheduled between Dublin Airport and Heathrow on Friday.
Dublin Airport advised affected passengers to contact their airline.
Data published earlier this year by the consultancy OAG suggests Dublin-Heathrow is the second busiest international air route in Europe.
It had 2.35 million seats available in 2024, just behind Rome Fiumicino to Madrid.
Travel journalist Simon Calder has told the BBC that he believes this is the first time London Heathrow has completely shut down since 2010.
The 2010 Eyjafjallajokull volcano eruption sent a huge ash plume several kilometres into the atmosphere, grounding thousands of flights across Europe, including in Northern Ireland.
Dublin Airport disruption may last days
Graeme McQueen, the media relations manager at the Dublin Airport Authority has told RTÉ’s Morning Ireland that the disruption is likely to last a few days.
“I think if you can get onto your airline, discuss it with them, whether you can maybe move to one of the other airports in London because it seems very likely that the knock-on impact will carry on for a number of days on this,” he said.
He added that other flights are not affected by the delays, and everything is moving well but there could be some knock-on effect later due to flights being diverted.
Shannon Airport in County Clare has said it has facilitated several diverted flights originally scheduled to land at Heathrow on Friday morning, including flights from Toronto, Atlanta, Bridgetown Barbados, Boston, Orlando and Newark.
Advice from Belfast City Airport
At the scene: Ita Dungan, BBC News NI
Belfast City Airport is showing three cancelled flights to London Heathrow this morning. All other scheduled flights are showing as on time.
Most people scheduled to travel to Heathrow this morning appeared to have heeded advice and not travelled to the airport and have contacted their airline for guidance.
Those few who did come to Belfast City Airport and sitting in their phones, either on hold to their airline or trying to rebook.
One young American couple that I spoke to had been booked on the 08:40 GMT flight to Heathrow.
They also had onward flights booked to Chicago and then on to Tulsa.
They spent 40 minutes trying to get through to American Airlines to get guidance on what to do next.
After eventually getting through, the earliest they can travel is tomorrow evening.
They are now heading back to their hotel.
