A full investigation has been ordered into the major power outage at Heathrow Airport, which brought operations to a standstill on Friday and affected around 200,000 passengers.
The disruption, caused by a fire at an off-site substation in Hayes, forced the closure of Europe’s busiest airport and resulted in the cancellation and delay of hundreds of flights.
On Saturday, Energy Secretary Ed Miliband announced that the National Energy System Operator (Neso) will lead an urgent investigation into the incident. The inquiry is being launched using powers under the Energy Act, in coordination with Ofgem, to determine how such a significant failure occurred and how energy resilience for critical national infrastructure can be improved.
"We are determined to properly understand what happened and what lessons need to be learned," said Mr Miliband. "The Government is committed to doing everything it can to prevent a repeat of what happened at Heathrow."
The National Energy System Operator is expected to deliver its initial findings within six weeks, reporting to the Department for Energy Security and Net Zero and Ofgem.
Heathrow Launches Internal Review
Alongside the government inquiry, Heathrow Airport has launched its own internal review into crisis response and management protocols, to be led by former Transport Secretary Ruth Kelly, who is also an independent member of the airport’s board.
Heathrow Chairman Lord Paul Deighton said:
"We are committed to finding any potential learnings from this unprecedented incident. To fully understand what happened, I have asked Ruth Kelly to undertake a thorough review of our response."
A spokesperson for Heathrow added:
"We apologise for the inconvenience caused by our decision to close the airport on Friday following a significant fire at an off-site power substation.
Today we will operate another full schedule of over 1,300 flights. Yesterday, we served more than 250,000 passengers, with punctual flights and almost all passengers waiting less than five minutes for security."
How the Incident Unfolded
The chaos began on Thursday evening, when a fire broke out at the North Hyde substation in Hayes, leading to a widespread power outage that forced Heathrow to suspend operations for nearly 24 hours. The outage also affected thousands of homes nearby, and more than 100 people were evacuated.
According to Heathrow Chief Executive Thomas Woldbye, a backup transformer failed during the outage, triggering automatic safety shutdowns. The airport was left with only two functioning substations to manage the power load required to operate what he described as the equivalent of a "mid-sized city."
While counter-terrorism officers from the Metropolitan Police initially led the investigation as a precaution, the fire is not believed to be suspicious, and the London Fire Brigade has now taken over the probe, focusing on the electrical distribution equipment.
Ongoing Recovery and Passenger Impact
Although operations resumed on Friday evening, the fallout from the closure has been considerable, with about 200,000 travellers disrupted, missed connections, and significant delays. The temporary lifting of overnight flight restrictions was introduced to help airlines manage the backlog.
Heathrow served more than 83.9 million passengers in 2024, making it one of the most critical transportation hubs in Europe. The scale of disruption has triggered fresh debate about infrastructure resilience and the risks of relying on ageing electrical systems to support such essential services.
As investigations continue, passengers are being encouraged to check flight status before travelling and to allow extra time at the airport.
