Heathrow Airport: Thousands of Irish hit by cancellation chaos; power restored but airport remains closed as counter-terror police lead probe into fire

The closure of Britain’s Heathrow Airport is set to affect the global aviation system for days at a cost of tens of millions of dollars, experts say, posing questions about why better contingency planning was not in place at the hub.

Experts were in shock at the scale of the outage, which has not been seen since the Icelandic ash cloud of 2010, as they tried to estimate the cost and breadth of the repercussions caused by a fire at a nearby electrical substation that knocked out the airport’s power supply and its back-up power.

Heathrow processes around 1,300 flights a day, according to Eurocontrol. The blaze, which was reported just after 11 p.m. (2300 GMT) on Thursday, forced planes to divert to airports across Britain and Europe, while many long-haul flights simply returned to their point of departure.

The cost of the impact could total around 20 million pounds ($26 million) a day, said Paul Charles, a travel consultant, with no guarantee that Heathrow will reopen on Saturday given…