The head of the UK’s National Grid, John Pettigrew, has stated that Heathrow Airport had “enough power” to remain operational despite the electrical substation fire that forced its closure on March 21, 2025.
The shutdown, which lasted almost a day, disrupted thousands of passengers and flights worldwide, sparking concerns over the reliability of the UK’s busiest airport.
Pettigrew told the Financial Times that power was still available through two other substations, emphasizing that each substation alone could supply Heathrow’s power needs.
“Losing a substation is a rare event, but there were two others available,” he explained.
However, airport officials attributed the closure to the time required to safely transition power to the other substations and reboot critical systems.
“Hundreds of essential airport systems had to be safely shut down and restarted, making the process highly complex,” a Heathrow spokesperson said.
Heathrow CEO Thomas Woldbye added that a backup transformer failure forced them to restructure power supplies before resuming operations.
The UK government has launched a six-week investigation into the incident, which disrupted 1,350 flights and forced 120 Heathrow-bound planes to divert.
Meanwhile, fire officials have classified the Thursday night blaze as non-suspicious, focusing their probe on electrical distribution equipment.
