Heathrow Power Cut Was Due to Issue Raised Seven Years Ago

The cause of a “catastrophic failure” of critical equipment at an electrical substation serving London’s Heathrow was detected in 2018 but ignored by National Grid Plc, according to an official report on the incident.

A massive power outage that crippled operations at Europe’s busiest airport in March resulted from a buildup of moisture inside the substation’s “bushing” — insulators that keep high-voltage environments operating safely. That led the oil, used for cooling, to catch fire.