The substation fire that shut Heathrow for most of March 21st turned out to be the latter—prompting a blame game between the airport and Britain’s electricity-system operator. (Heathrow’s chairman, Lord Deighton,

Britain's aviation watchdog will consider Heathrow airport's resilience rules as part of a regular review, it said on Thursday, following a closure last week that disrupted global flight schedules and stranded thousands of passengers.

Heathrow was shut in the early hours of Friday last week after the fire at the Hayes substation in west London hit electricity supplies.