A reads “Do Not Travel To Heathrow Airport” at Hounslow Central London Underground station on March 21, 2025.
Jaimi Joy | Bloomberg | Getty Images
Heathrow Airport had enough power to remain open on Friday, after the London hub spent most of the day closed due to a fire at a nearby electrical substation, according to Britain’s National Grid.
Heathrow — Europe’s busiest airport — closed down last week after a fire broke out at a nearby electrical substation that supplies it with power.
In comments first reported by the Financial Times, National Grid CEO John Pettigrew said that although the substation in question had been damaged in the “unprecedented” fire, two others supplying power to Heathrow had been operating as normal throughout the day.
“There was no lack of capacity from the substations,” he said. “Each substation individually can provide enough power to Heathrow.”
National Grid, a publicly listed company, owns the high-voltage electricity transmission network in England and Wales. The firm confirmed Pettigrew’s comments with via email on Monday.
A spokesperson for Heathrow argued, however, that it would have been impossible for Heathrow to operate uninterrupted after the fire last week.
“As the National Grid’s chief executive, John Pettigrew, noted, he has never seen a transformer failure like this in his 30 years in the industry,” they said in emailed comments on Monday. “Hundreds of critical systems across the airport were required to be safely powered down and then safely and systematically rebooted. Given Heathrow’s size and operational complexity, safely restarting operations after a disruption of this magnitude was a significant challenge.”
Speaking to the BBC on Saturday, Heathrow CEO Thomas Woldbye defended the airport’s response to what he labeled a “major incident.”
“We have other substations but to switch them in takes time,” he said. “The situation was not created at Heathrow Airport, it was created outside the airport and we had to deal with the consequences.”
Heathrow has ordered an internal probe into the shutdown and its crisis management plan, while the U.K. government has commissioned its own investigation into the incident.
More than 1,300 flights had been scheduled to take off from or arrive at Heathrow on Friday, according to news agency Reuters. More than 120 that were already airborne when Heathrow closed were diverted to other airports or returned to their city of departure. The disruption is widely expected to cost airlines millions of dollars.
As the situation unfolded on Friday, European travel and leisure stocks saw a broad selloff. British Airways owner IAG shed around 1.9% of its value, while Lufthansa lost 1.7%, and Easyjet was down almost 1%. Many regional airline stocks ended Friday’s trading session lower, despite recovering from deeper losses seen earlier in the session.
On Monday, Europe’s travel and leisure shares were trading around 0.4% higher, with IAG up 0.9% and Lufthansa gaining 0.3% by 1:20 p.m. in London.
In a statement on Friday, the International Air Transport Association (IATA) — a trade body representing 340 airlines that collectively account for 80% of global air traffic — slammed Heathrow’s response to the substation fire.
“This is yet another case of Heathrow letting down both travelers and airlines,” IATA Director General Willie Walsh said. “How is it that critical infrastructure — of national and global importance — is totally dependent on a single power source without an alternative. If that is the case — as it seems — then it is a clear planning failure by the airport.”
Walsh added that the incident also raised questions about who should bear the costs of taking care of disrupted travelers.
“We must find a fairer allocation of passenger care costs than airlines alone picking up the tab when infrastructure fails,” he said.
Stephen Rooney, a specialist in tourism economics at Oxford Economics, estimated in a note on Friday that the closure would translate to £4.5 million ($5.82 million) in lost tourism revenue for the U.K., while Jonathan Owens, senior lecturer in operations and supply chain management at the University of Salford’s Business School, told on Monday that the economic impact would be “massive.”
“The costs associated with diverting flights to alternate airports are significant, both in terms of financial implications and logistical challenges,” he said via email.
“Flights diverted to other airports would need to cover additional fuel, air traffic control services and airport fees … Passengers affected by flight diversions or cancellations are very likely to seek compensation because of hotel accommodations, meals and taxis, which all add to the cost for airlines.”
