National Grid aware of fault behind Heathrow shutdown fire for seven years
Cause of catastrophic power outage that shut down Heathrow revealed
- A fire at the North Hyde electricity substation on 20 March caused a catastrophic power outage, leading to the near-complete closure of Heathrow Airport the next day.
- The National Energy System Operator's final report attributed the fire to a known transformer problem, with National Grid failing to act on an elevated moisture reading detected in 2018 that indicated an imminent fault.
- Heathrow Airport was aware of the potential for power disruption, classifying a total loss of power as a high-impact, low-probability event, and its internal electrical network was not configured for quick recovery, relying on manual switching.
- The incident resulted in over 1,400 flight cancellations and an estimated £100 million in losses for airlines.
- Ofgem has launched an investigation into the incident, while Heathrow blamed outdated regulation and National Grid's maintenance failures.