London Heathrow Airport resumes operations after nearby fire, but backlogs expected

The closure of Britain's Heathrow Airport is set to affect the global aviation system for days and cost tens of millions of dollars, experts say, raising questions over why better contingency planning was not in place at the world's fifth-largest airport.

Experts were in shock at the scale of disruption — the largest since the Icelandic ash cloud of 2010 — as they tried to estimate the cost and breadth of the repercussions caused by a fire at a nearby electrical substation that knocked out the airport's power supply and its backup power.

"It is a clear planning failure by the airport," said Willie Walsh, head of the International Air Transport Association, who, as former head of British Airways, has for years been a fierce critic of the crowded hub.

The London-area airport said on Friday it was resuming flights and expects to run a full operation on Saturday.

The fire, which was reported just after 11 p.m. local time on Thursday, forced planes to divert to airports across Britain and Europe, while many long-haul flights simply returned to their point of departure.

Huge orange flames and plumes of black smoke could be seen shooting into the sky from a power station roughly three kilometres from the airport. It took about 70 firefighters and seven hours to get the blaze under control, the London Fire Brigade said. By early morning the roads around Britain's biggest airport were largely deserted.

Police said that while there was no indication of a criminal cause to the blaze, they retained an open mind and counter-terrorism officers would lead the inquiries, given their capabilities and the critical nature of the infrastructure.

Energy Minister Ed Miliband said the "catastrophic" fire had prevented the power backup system from working and that engineers were working to deploy a third backup mechanism. 

Philip Ingram, a former intelligence officer in the British military, said Heathrow's inability to keep operating exposed vulnerability in Britain's critical national infrastructure.

"It is a wake-up call," he told Reuters. "There is no way that Heathrow should be taken out completely because of a failure in one power substation."

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

Heathrow said its expectation was "to operate our normal schedule starting with [Friday] evening's departures," but that "customers should check the status of their flight before going to the airport."

Air Canada flights rerouted

Air Canada said six flights that were in the air had to return to their departure points, while a seventh was cancelled just before departing. That list included flights from Calgary, Toronto and Montreal.

"We have been able to reroute some customers to other European gateways, but our available space for doing so is limited," the airlines said in a statement. "As well, we have put in place a policy for customers travelling to London to change their travel plans."

"Once we are told by Heathrow how many flights we will be permitted to operate we will finalize tonight's schedule and notify customers and, as the situation normalizes, we will look to add extra capacity if needed to move delayed customers."

Since the Heathrow closure was announced, a Friday morning flight from Halifax to London was cancelled, as were six more that had been scheduled for later in the day, which were departing from Toronto, Calgary, Montreal and Vancouver.

The Greater Toronto Airports Authority (GTAA) advised travellers heading to Pearson Airport to check the status of their departures with their airline and that Pearson's social media accounts would provide regular updates.

"Currently all arriving flights are cancelled," the GTAA told CBC News.

A representative from Montreal-Trudeau International Airport said that three flights that were to depart late Thursday were affected and that two departures to Heathrow were cancelled Friday.

Vancouver International Airport said one Air Canada flight late Thursday was forced to return after taking off, while a British Airways flight was cancelled beforehand. The airport said a late Friday afternoon Air Canada flight to Heathrow and a British Airways departure scheduled for Friday night are scheduled to operate on time, but that travellers are advised to check ahead given the fluid situation.

'It's pretty stressful'

The fire brigade said that 25,000 litres of cooling oil in the substation's transformer had caught fire. By the morning, the transformer could be seen smouldering, doused in white firefighting foam.

The cost of the impact could total around 20 million pounds ($37 million Cdn) a day, said Paul Charles, a travel consultant.

"A backup should be failsafe in the event of the core system being affected. Heathrow is such a vital piece of British infrastructure that it should have failsafe systems," Charles told Reuters.

Heathrow had said the airport, which was due to handle 1,351 flights during the day, flying up to 291,000 passengers, would stay closed until midnight, until amending the timeline late Friday afternoon local time.

Heathrow normally opens for flights daily at 6 a.m. local time due to nighttime flying restrictions.

Some 120 flights were in the air when the closure was announced, with some turned around and others diverted to Gatwick Airport outside London, Charles de Gaulle Airport in Paris or Ireland's Shannon Airport, tracking services showed.

British Airways itself had 341 flights scheduled to land at Heathrow on Friday.

"It's pretty stressful," said Robyn Autry, 39, a professor who had been due to fly home to New York. "I'm worried about how much is it going to cost me to fix this."

Prices at hotels around Heathrow jumped, with booking sites offering rooms for 500 pounds ($925 Cdn), roughly five times the normal price levels.

The closure is set to have days-long knock-on effects globally, leaving many passengers stranded as carriers reconfigure their networks to move planes and crews around.

British Airways has warned in the past that Heathrow is so overstretched that recovering from disruption can cause even more chaos, as planes and staff must be properly repositioned even as the facility runs at full capacity.

"There will be impact running on several days, because once aircraft are grounded somewhere away from an operation, they are stuck there with the crews operating the flights," said aviation consultant and network planning expert John Strickland.

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

Heathrow had its busiest January on record earlier this year, with more than 6.3 million passengers, up more than five per cent from the same period last year. January also was the 11th month in a row that it averaged over 200,000 passengers a day, with the airport citing trans-Atlantic travel as a key contributor.