A power outage that shut Heathrow Airport earlier this year, causing travel chaos for more than 270,000 passengers, was caused by a “catastrophic failure” of equipment in a nearby substation, according to a new report.
Experts say the fire at the North Hyde Substation, which supplies electricity to Heathrow, started following the failure of a high-voltage electrical insulator known as a bushing, before spreading.
The failure was “most likely” caused by moisture entering the equipment, according to the report.
Image: The fire at Hayes electrical substation, which led to Heathrow Airport shutting down in March. Pic: @JoselynEMuirhe1/PA
National Grid, which owns the substation, missed two opportunities to prevent the failure, experts found, the first in 2018 when a higher-than-expected level of moisture was found in oil samples.
Such a reading meant “an imminent fault and that the bushing should be replaced”, according to guidance by the National Grid Electricity Transmission.
However, the report by National Energy System Operator (NESO) said the appropriate responses to such a serious issue were “not actioned”, including in 2022 when basic maintenance was postponed.
“The issue therefore went unaddressed,” the report added.
Please use Chrome browser for a more accessible video player
0:21
Moment Heathrow substation ignites
The design and configuration of the airport’s internal power network meant the loss of just one of its three supply points would “result in the loss of power to operationally critical systems, leading to a suspension of operations for a significant period”, the report added.
Heathrow – which is Europe’s biggest airport – closed for around 16 hours on 21 March following thefire, before reopening at about 6pm.
Image: The North Hyde electrical substation which caught fire. File pic: PA
Tens of millions of pounds were lost, thousands of passengers were stranded, and questions were raised about the resilience of the UK’s infrastructure.
More than 71,000 domestic and commercial customers lost power as a result of the fire and the resulting power outage, the report said.
NESO chief executive, Fintan Slye, said there “wasn’t the control within their [National Grid’s] asset management systems that identified that this [elevated moisture levels] got missed.
“They identified a fault, [but] for some reason the transformer didn’t immediately get pulled out of service and get repaired.
Image: Smoke rises following the fire
“There was no control within the system that looked back and said ‘oh, hang on a second, you forgot to do this thing over here’.”
Sky’s science and technology editor, Tom Clarke, pointed to the age of the substation’s equipment, saying “some of these things are getting really very old now, coming to the end of their natural lives, and this is an illustration of what can happen if they are not really well maintained”.
The report also highlights a lack of joined-up thinking, he said, as “grid operators don’t know who’s critical national infrastructure on the network, and they don’t have priority”.
Please use Chrome browser for a more accessible video player
0:49
Heathrow bosses were ‘warned about substation’
Responding to the report’s findings, a Heathrow spokesperson said: “A combination of outdated regulation, inadequate safety mechanisms, and National Grid’s failure to maintain its infrastructure led to this catastrophic power outage.
“We expect National Grid to be carefully considering what steps they can take to ensure this isn’t repeated.
“Our own Review, led by former Cabinet Minister Ruth Kelly, identified key areas for improvement and work is already underway to implement all 28 recommendations.”
In May, Ms Kelly’s investigation revealed that the airport’s chief executive couldn’t be contacted as the crisis unfolded because his phone was on silent.
Image: Stranded passengers at Heathrow Terminal 5 following the fire
Pic: PA
Energy Secretary Ed Miliband, who commissioned the NESO report, called it “deeply concerning”, because “known risks were not addressed by the National Grid Electricity Transmission”.
Mr Miliband said energy regulator Ofgem, which opened an investigation on Wednesday after the report was published, is investigating “possible licence breaches relating to the development and maintenance of its electricity system at North Hyde.
“There are wider lessons to be learned from this incident. My department, working across government, will urgently consider the findings and recommendations set out by NESO and publish a response to the report in due course.”
National Grid said in a statement it has “a comprehensive asset inspection and maintenance programme in place” and said it has “taken further action since the fire”.
This includes “an end-to-end review” of its oil sampling process and results, further enhancement of fire risk assessments at all operational sites, and “re-testing the resilience of substations that serve strategic infrastructure”.
A spokesperson said: “We fully support the recommendations in the report and are committed to working with NESO and others to implement them. We will also cooperate closely with Ofgem’s investigation.
“There are important lessons to be learnt about cross sector resilience and the need for increased coordination, and we look forward to working with government, regulators and industry partners to take these recommendations forward.”
The CBI has begun a search for a successor to Rupert Soames, its chairman, as it continues its recovery from the crisis which brought it to the brink of collapse in 2023.
Sky News has learnt that the business lobbying group’s nominations committee has engaged headhunters to assist with a hunt for its next corporate figurehead.
Mr Soames, the grandson of Sir Winston Churchill, was recruited by the CBI in late 2023 with the organisation lurching towards insolvency after an exodus of members.
The group’s handling of a sexual misconduct scandal saw it forced to secure emergency funding from a group of banks, even as it was frozen out of meetings with government ministers.
One prominent CBI member described Mr Soames on Thursday as the group’s “saviour”.
“Without his ability to bring members back, the organisation wouldn’t exist today,” they claimed.
Mr Soames and Rain Newton-Smith, the CBI chief executive, have partly restored its influence in Whitehall, although many doubt that it will ever be able to credibly reclaim its former status as ‘the voice of British business’.
Its next chair, who is also likely to be drawn from a leading listed company boardroom, will take over from Mr Soames early next year.
Egon Zehnder International is handling the search for the CBI.
“The CBI chair’s term typically runs for two years and Rupert Soames will end his term in early 2026,” a CBI spokesperson said.
“In line with good governance, we have begun the search for a successor to ensure continuity and a smooth transition.”
Ryanair and easyJet have cancelled hundreds of flights as a French air traffic controllers strike looms.
Ryanair, Europe’s largest airline by passenger numbers, said it had axed 170 services amid a plea by French authorities for airlines to reduce flights at Paris airports by 40% on Friday.
EasyJet said it was cancelling 274 flights during the action, which is due to begin later as part of a row over staffing numbers and ageing equipment.
The owner of British Airways, IAG, said it was planning to use larger aircraft to minimise disruption for its own passengers.
The industrial action is set to affect all flights using French airspace, leading to wider cancellations and delays across Europe and the wider world.
Ryanair said its cancellations, covering both days, would hit services to and from France, and also flights over the country to destinations such as the UK, Greece, Spain and Ireland.
More from Money
Group chief executive Michael O’Leary has campaigned for a European Union-led shake-up of air traffic control services in a bid to prevent such disruptive strikes, which have proved common in recent years.
He described the latest action as “recreational”.
Image: Michael O’Leary. Pic: Reuters
“Once again, European families are held to ransom by French air traffic controllers going on strike,” he said.
“It is not acceptable that overflights over French airspace en route to their destination are being cancelled/delayed as a result of yet another French ATC strike.
“It makes no sense and is abundantly unfair on EU passengers and families going on holidays.”
Ryanair is demanding the EU ensure that air traffic services are fully staffed for the first wave of daily departures, as well as to protect overflights during national strikes.
“These two splendid reforms would eliminate 90% of all ATC delays and cancellations, and protect EU passengers from these repeated and avoidable ATC disruptions due to yet another French ATC strike,” Mr O’Leary added.
Following his remarks, the value of the pound dropped and government borrowing costs rose, via the interest rate on both 10 and 30-year bonds.
Although market fluctuations are common, there was a reaction following Sir Keir’s comments in the Commons – signalling concern among investors of potential changes within the Treasury.
Please use Chrome browser for a more accessible video player
1:07
PM refuses to rule out tax rises
Sterling dropped to a week-long low, hitting $1.35 for the first time since 24 June. The level, however, is still significantly higher than the vast majority of the past year, having come off the near four-year peak reached yesterday.
While a drop against the euro, took the pound to €1.15, a rate not seen since mid-April in the aftermath of President Donald Trump’s tariff announcements.
Meanwhile, the interest rate investors charge to lend money to the government, called the gilt yield, rose on both long-term (30-year) and ten-year bonds.
The UK’s benchmark 10-year gilt yield – so-called for the gilt edges that historically lined the paper they were printed on – rose to 4.67%, a high last recorded on 9 June.
And 30-year gilt yields hit 5.45%, a level not seen since 29 May.
Follow The World
Listen to The World with Richard Engel and Yalda Hakim every Wednesday
Ms Reeves has committed to self-imposed rules to reduce debt and balance the budget. Speculation around her future led investors to question the government’s commitment to balancing the books – and how they would do that.
The questions over her future came after the government scrapped the core money-saving component of its welfare bill, which had been intended to reduce spending in order to meet fiscal rules.