Wed, 02 Jul 2025

Wed, 02 Jul 2025 Five things we now know about the fire that shut Heathrow down

A report into a fire that resulted in Heathrow Airport shutting down for nearly a day has been released - what are the key findings?
1. The likely cause of the fire at the Heathrow Airport electricity substation was a short-circuit caused by moisture getting into the high-voltage "bushing" - insulation around connections. 2. Inspectors found signs of moisture in 2018, but National Grid did not fix the issue at the time and instead deferred basic maintenance on the transformer in 2022. 3. Heathrow Airport knew that if one of its electricity connections went down, it would have to shut down for 10-12 hours while key systems were connected to other sources of supply. 4. The report recommends better communication between critical national infrastructure operators (such as Heathrow) and their energy suppliers to ensure uninterrupted supplies. 5. National Grid had been warned about the fault seven years ago, but did not take sufficient action to prevent the fire, leading Heathrow Airport to consider legal action against them.
  >>