The impact of the Heathrow shutdown will not be resolved quickly and will have a knock-on impact on all travel for the next few days, travel industry experts have warned.
The UK’s major transport hub was forced to shut down for the entire day on Friday after a fire at a nearby electrical substation caused a major power outage across west London.
The blaze broke out shortly before midnight on Thursday at the North Hyde substation on Nestles Avenue in Hayes. A transformer caught fire, leading to widespread disruption.
“An incident like this at one of the world’s busiest airports will have a very significant knock-on impact on all travel for the next few days,” said Julia Lo Bue-Said, chief executive of the Advantage Travel Partnership.
She added that Friday is typically the busiest day for travel, with people returning from business trips or heading off for weekend breaks.
“London airports would have been busy today already and this incident will exacerbate it further,” said Lo Bue-Said.
Aviation consultant John Strickland said recovering from a full-day closure at Heathrow would take “several days” and cost the industry millions of pounds.
“Heathrow has normally about 200,000 passengers a day, so it’s a massive impact in lost revenues and disruption costs, primarily for the airlines [because of] all the follow-on costs involved in putting people in hotels, refunds, re-bookings etc.”
Strickland described it as a “massive dislocation,” likening it to a “contained version of 9/11 or, to an extent, the Icelandic volcanic eruption” in terms of aviation disruption.
Prime Minister Sir Keir Starmer acknowledged the “distress and disruption” cause by the Heathrow shutdown and the fire.
Scale of the Disruption
Ten fire engines and around 70 firefighters tackled the flames overnight.A 200-metre safety cordon was established, and around 150 people were evacuated from nearby homes.
London Fire Brigade Assistant Commissioner Pat Goulbourne described the fire as a “very visible and significant incident,” with crews working in “challenging conditions” to bring it under control by 6:28 a.m. on Friday.
While there were no injuries, London Fire Brigade advised residents to keep windows closed owing to lingering smoke.

Power was lost to more than 100,000 homes at the height of the outage, though the number was reduced to around 4,000 by morning.
As a result of the outage, Heathrow—Britain’s busiest airport—announced it would remain closed until 23:59 on March 21. The airport confirmed it had “no choice” but to suspend operations to protect the safety of passengers and staff.
More than 1,350 flights have been affected, including 679 arrivals and 678 departures, according to online tracking site Flightradar24.
Around 120 flights were airborne at the time the closure was announced. The disruption has impacted over 200,000 passengers, with many left stranded.
Knock-on Effects
The closure has had ripple effects throughout the UK and Europe.Dublin Airport cancelled all 34 scheduled flights to and from Heathrow on Friday. Media relations manager Graeme McQueen warned of further potential disruption over the weekend.
Elsewhere, EasyJet, which does not operate from Heathrow, said it would use larger aircraft on routes between major European cities to help accommodate displaced passengers.
Several Heathrow-bound flights were diverted mid-air to airports including Gatwick, Paris Charles de Gaulle, and Shannon in Ireland. Some transatlantic flights even turned back to the United States and Canada.
Gatwick Airport accepted seven diverted flights from cities including Singapore, Johannesburg, Cape Town, Lagos, and Doha. Shannon Airport received six diversions from Toronto, Atlanta, Boston, Bridgetown, Orlando, and Newark.

British Airways, the largest carrier at Heathrow, said it was working “as quickly as possible” to update customers and advised passengers not to travel to the airport. It admitted the outage would have a “significant impact” on its operations.
Heathrow’s Key Role
Heathrow is the UK’s largest airport by a wide margin.In 2024, it handled nearly 84 million passengers, which is more than double the number seen at the next busiest airport, Gatwick. Of those passengers, 94 percent were travelling on international routes. Civil Aviation Authority figures show the airport handled an average of 1,317 aircraft a day last year.
Investigation Underway
London Fire Brigade and the Metropolitan Police are investigating the cause of the fire. Emergency services were called to the scene at 11:23 p.m. on Thursday night, and the fire was brought under control just over seven hours later.Energy Secretary Ed Miliband said the fire had apparently knocked out both the substation and its backup generator. He pledged a review of infrastructure resilience at key national sites like Heathrow.
“It’s too early to say what caused this, but we’ll need to look at the resilience in place,” he told BBC Radio 4’s “Today” programme.
The National Grid confirmed that the fire had damaged critical equipment and said engineers were “working at speed” to restore full service. The network told Miliband that it had not seen “anything like the scale” of what happened with the “seriousness” of the fire.
“But it makes Heathrow look quite vulnerable and therefore we’ve got to learn lessons, as I say, about not just Heathrow but how we protect our major infrastructure,” Miliband said.
In its latest statement, the airport said: “We know this will be disappointing for passengers, and we want to reassure them that we are working as hard as possible to resolve the situation. We will provide further updates as soon as we can.”
Travellers with flights scheduled in the coming days are advised to monitor airline communications and check for updates online before making any travel arrangements.