Airport officials say Heathrow will be closed until at least 11.59pm, impacting up to 290,000 people, according to Cirium, an aviation analytics company. Some of the 120 flights already on their way to the hub are still air-borne, as planes scout for airports to land in.

The first plane landed at Heathrow Airport late Friday, about 18 hours after an inferno at an electrical substation caused a power outage that shuttered