Global flight turmoil as London's Heathrow closed by huge fire

Britain's Heathrow Airport was shut on Friday after a huge fire at a nearby substation knocked out its power, stranding passengers around the world and angering airlines who questioned how such crucial infrastructure could fail.

Huge orange flames and plumes of black smoke shot into the sky around 2300 GMT on Thursday as a blaze engulfed the substation, cutting the power supply and backup system for Europe's busiest and the world's fifth-busiest airport.

Police said while there was no indication of foul play they retained an open mind and counter-terrorism officers would lead the inquiries given the critical nature of the infrastructure, and their capabilities.

Airline experts said the last time European airports experienced disruption on such a large scale was the 2010 Icelandic ash cloud that grounded some 100,000 flights.

The industry is now facing the prospect of a financial hit costing tens of millions of pounds, and a likely fight over who should pay.

"You would think they would have significant backup power," one top executive from a European airline told Reuters.

The fire brigade said the cause of the fire was not known, but that 25,000 liters of cooling oil in the substation's transformer had caught fire. It had brought the blaze under control by the early morning with the transformer doused in white firefighting foam.

Heathrow had been due to handle 1,351 flights on Friday, flying up to 291,000 passengers. The closure forced flights to divert to other airports in Britain and across Europe, while many long-haul flights returned to their point of departure.

Passengers stranded in London and facing the prospect of days of disruptions were scrambling to make alternate travel arrangements.

"When we first came here, (it was) very exciting and hopeful," said Beau Mahr, 21 from the US state of Iowa. "Now that we have to wait, it's kind of stressful."

Industry experts warned that some passengers forced to land in Europe may have to stay in transit lounges if they lack the paperwork to leave the airport.

Global flight schedules will also be affected, as aircraft and crews will now be out of position, forcing carriers to rapidly reconfigure their networks.

Prices at hotels around Heathrow jumped, with booking sites offering rooms for 500 pounds (US$645), roughly five times the normal price levels.

"Passengers are advised not to travel to the airport and should contact their airline for further information," Heathrow said, adding that the airport would be shut until midnight on Friday. "We apologize for the inconvenience."

Back-up power

Airline executives, electrical engineers, and passengers questioned how Britain's gateway to the world could be forced to close by one fire, however large.

Heathrow, and London's other major airports, have been hit by other outages in recent years, most recently by an automated gate failure and an air traffic system meltdown, both in 2023.

Pictures on social media showed the airport terminals in near darkness during the night, and British energy minister Ed Miliband said it appeared that the "catastrophic" fire had prevented the power backup system from working.

Willie Walsh, the head of the global airlines body IATA and a former head of British Airways, said Heathrow had once again let passengers down.

"How is it that critical infrastructure - of national and global importance - is totally dependent on a single power source without an alternative," he said. "If that is the case - as it seems - then it is a clear planning failure by the airport."

Experts in power supply said the type of fire that erupted overnight was extremely rare, but they added that there should be sufficient alternative supplies to get everyone back online quickly.

"We can be fairly confident they will be able to restore by tomorrow," said Nicholas Rigby, a commercial engineer at NRG Management Consultancy.

Prime Minister Keir Starmer said he was receiving regular updates on the incident.

Midnight flight scramble

As the scale of the outage became clear, flights operated by airlines including JetBlue, American Airlines, Air Canada, Air India, Delta Air, Qantas, United Airlines, IAG-owned British Airways, and Virgin were diverted or returned to their origin airports in the middle of the night, according to data from flight analytics firm Cirium.

Qantas Airways sent its flight from Perth to Paris, a United Airlines New York flight headed to Shannon, Ireland, and a United Airlines flight from San Francisco was due to land in Washington, DC rather than London.

"Heathrow is one of the major hubs of the world," said Ian Petchenik, spokesman for flight tracking website FlightRadar24. "This is going to disrupt airlines' operations around the world."

British Airways, the biggest carrier at Heathrow, had 341 flights scheduled to land there on Friday.

Shares in its parent company IAG ICAG.L were hit, along with shares in other airlines. EasyJet and Ryanair put on extra flights or used larger planes to help tackle the backlog.

A Heathrow spokesperson said there was no clarity on when power would be restored, and they expected significant disruption over the coming days.

The airport's owners include France's Ardian, the Qatar Investment Authority, and Saudi Arabia's Public Investment Fund, plus other investors in Australia, China, and Spain.

On the ground in London, thousands of properties were also without power. Businesses in the area include data centers and logistics warehouses.