Power appears to have returned to Heathrow but airport remains closed
The airport announced early on Friday it would be closed until 11.59pm because of a fire at a nearby electrical substation.
Power appears to have returned to Heathrow airport but it remains closed after an outage caused by a fire.
National Grid said an “interim solution” has been found to allow power to be restored to the west London airport.
PA news agency reporters inside Terminal 4 on Friday afternoon said lights in the main building have switched back on and lifts in the multi-storey car park are operational again.
The airport announced early on Friday it would be closed until 11.59pm because of a fire at a nearby electrical substation.
Around 200,000 passengers have been affected by the closure of what is Europe’s busiest airport.
Online flight tracking service Flightradar24 said more than 1,350 flights were scheduled to take off or land at the airport on Friday.
Disruption will last for several days even if the airport reopens on Saturday, as many planes and flight crews are out of position.
London Fire Brigade said it received the first reports of the fire at 11.23pm on Thursday, forcing the closure of the airport.
Some 120 aircraft heading to the airport at that time were forced to either divert or return to their point of origin.
A National Grid spokesperson said: “We’re sorry for the disruption caused by a fire at our North Hyde substation and for the loss of power supplies in the area.
“Teams have been working around the clock to restore power as soon as possible.
“Working in partnership with the local network operator SSEN Distribution (SSEN), the network has been reconfigured to restore all customers impacted, including the ability to resupply the parts of Heathrow airport that are connected to North Hyde.
“This is an interim solution while we carry out further work at North Hyde to return the substation and our network to normal operation.”
Heathrow previously said it did not have “clarity on when power may be reliably restored” and warned that “we expect significant disruption over the coming days”.
British Airways chief executive Sean Doyle described the closure of the airport as “unprecedented”, and one that will have a “huge impact” on the airline’s customers.
“We hope that power will be restored as soon as possible,” he said. “But even when that does happen, this incident will have a substantial impact on our airline and customers for many days to come, with disruption to journeys expected over the coming days.
“To give you an idea of the scale of disruption we face which we’re working to minimise, today we were due to operate more than 670 flights carrying around 107,000 customers, with similar numbers planned over the weekend.”
Counter-terrorism officers from the Metropolitan Police are leading the investigation into the cause of a fire.
The force said there was “no indication of foul play” but “we retain an open mind at this time”.
Thousands of homes were left without power and more than 100 people were evacuated after a transformer within the substation caught fire.
Heathrow is Europe’s largest airport, with more than 83.9 million passengers travelling through its terminals in 2024.
It said its back-up power systems “operated as expected” but they are not designed to “allow us to run a full operation”.
This is believed to be the worst disruption at Heathrow since December 2010, when thousands of Christmas getaway passengers camped in the terminals because of widespread cancellations caused by snow.
In April of that year, air travel was grounded across Europe because of an ash cloud caused by an Icelandic volcanic eruption.
On Friday, Gatwick airport accepted seven diverted flights from locations including Singapore, Johannesburg, Lagos, Cape Town and Doha which were originally destined for Heathrow.
Shannon airport in Co Clare accepted six diversions from Toronto, Atlanta, Bridgetown Barbados, Boston, Orlando and Newark.
Aviation consultant John Strickland said the closure of Heathrow for an entire day is “a massive dislocation to have to recover from”.
He added: “We’re talking about several days worth of disruption to get the planes recovered and start using them again to move planned and disrupted passengers.”
He likened the disruption to what happened after the September 11 terrorist attacks in 2001, when flights were grounded across the US.
He said: “It’s a contained version of 9/11.”
Rory Boland, editor of magazine Which? Travel, said affected passengers are not entitled to compensation but airlines should provide assistance such as overnight accommodation if required and re-routing bookings, including with rival carriers from alternative airports.
Around 150 people were evacuated from properties surrounding the substation and a 200-metre cordon was put in place as a precaution.
Speaking to broadcasters at the scene in Hayes, deputy commissioner Jonathan Smith said: “The fire involved a transformer comprising of 25,000 litres of cooling oil fully alight.
“This created a major hazard due to the still live high-voltage equipment and the nature of the oil-fuelled fire.”
A local resident, who did not want to be named, said she heard a “massive explosion”.
All the power went off, she said, adding: “It just smelled like burning.”
London Ambulance Service said there were no casualties at the scene of the fire.
Footage posted to social media showed huge flames and large plumes of smoke coming from the facility.
