Flights have resumed at Heathrow Airport as its chief executive apologized to stranded passengers and defended the response to an “unprecedented” loss of power caused by a substation fire. Thomas Woldbye described the blaze which knocked out an electricity substation in Hayes late on Thursday evening as “as big as it gets for our airport” and that “we cannot guard ourselves 100%”. The Metropolitan Police said they are not treating the incident as suspicious while the London Fire Brigade (LFB) announced its investigation will now focus on the electrical distribution equipment.
Of the power outage, Mr. Woldbye said that a back-up transformer failed meaning systems had to be closed down in accordance with safety procedures so that power supplies could be restructured from two remaining substations to restore electricity enough to power what is described as a “mid-sized city.” Meanwhile, Transport Secretary Heidi Alexander said there would be lessons to learn from the incident.
The west London airport initially announced it would be closed until 11:59 PM on Friday, March 21, 2025, but later said repatriation flights for passengers diverted to other airports in Europe would resume that evening. Several airlines announced they would restart scheduled flights both to and from Heathrow, including British Airways, Air Canada and United Airlines. Restrictions on overnight flights have also been temporarily lifted to help ease congestion, the Department of Transport said. Heathrow is expected to run a full schedule on Saturday.
Around 200,000 passengers have been affected by the closure of what is Europe’s busiest airport. Mr. Woldbye said, “I’d like to stress that this has been an incident of major severity. It’s not a small fire. We have lost power equal to that of a mid-sized city and our backup systems have been working as they should but they are not sized to run the entire airport.” Asked if there is a weak point in Heathrow’s power system, he said, “You can say that but of course contingencies of certain sizes we cannot guard ourselves against 100% and this is one of them.”
This has been a major incident. I mean, short of anybody getting hurt, this is as big as it gets for our airport and we are actually coming back quite fast I would say, when you consider the amount of systems that we have to shut down then bring back up and make sure that they’re safe.” He added, “This is unprecedented. It’s never happened before and that’s why I’m saying it has been a major incident.”
On Friday, March 21, 2025, around 6 PM, the first plane landed at Heathrow after the fire disrupted operations. The airport is running a reduced operation prioritizing repatriation and relocation of aircraft and suggesting passengers contact their airline for further information. The Transport Secretary said she was in close contact with the Energy Secretary and the Home Secretary to ensure that any lessons needed from the incident are learned.
An update from the London Fire Brigade indicated that their investigation will focus on the electrical distribution equipment. They received the first reports of the fire at 11:23 PM on Thursday, leading to the airport’s sudden closure. Around 120 aircraft heading to the airport that night were forced to divert or return to their point of origin.
Counter-terrorism officers from the Metropolitan Police have been leading the investigation into the cause of the fire. Commander Simon Messinger stated, “After initial assessment, we are not treating this incident as suspicious, although inquiries do remain ongoing.” Thousands of homes were left without power and more than 100 people were evacuated after a transformer within the substation caught fire.
Heathrow, which handled a record 83.9 million passengers last year, is believed to be experiencing its worst disruption since December 2010, when thousands of Christmas travelers camped in the terminals. Aviation consultant John Strickland likened the disruption to what happened after the September 11 terrorist attacks in 2001, saying, “It’s a contained version of 9/11.”
Rory Boland, editor of magazine Which? Travel, added that 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.
The LFB Deputy Commissioner Jonathan Smith described, “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-fueled fire.” A local resident said she heard a “massive explosion” before all the power went off, adding, “It just smelled like burning.” Fortunately, there were no casualties at the scene of the fire, according to the London Ambulance Service.
Meanwhile, video footage posted to social media showed huge flames and plumes of smoke pouring from the substation facility. The fire prompted some airlines to divert flights at the last minute. For instance, Qantas flights to Heathrow from Singapore and Perth were diverted to Paris before taking buses to London. Those stranded passengers expressed their frustrations through social media as they tried to navigate their travel chaos.
Experts highlighted the vulnerability of Britain’s infrastructure, with calls for a review of the electrical supply systems in the area. Ofgem, Britain's energy regulator, announced it would commission a review to understand the cause of this incident and what lessons can be learned.
The situation left many travelers scrambling for accommodations, with prices skyrocketing near the airport. Estimates indicated that one hotel was charging £1,000 for a standard room for two people – a staggering increase compared to its usual rates. The chaotic scene was amplified by thousands of travelers experiencing significant disruptions as flights had to be rescheduled or diverted.
In conclusion, while Heathrow is on the path toward normal operations with the full schedule projected for Saturday, the ripple effects of this incident are expected to affect air travel for days to come. Passengers are advised to check with their airlines for updates as the airport works to address the fallout from this major infrastructural incident.
