Heathrow shutdown raises serious questions about its backup plans

Closure of Europe's busiest airport from a substation fire causes global disruptions

- 

LONDON - Britain's Heathrow Airport was shut on March 21 after a huge fire at a nearby substation knocked out its power, stranding passengers around the world and angering airlines, which questioned how such crucial infrastructure could collapse.

Huge orange flames and plumes of smoke shot into the sky around 11 pm on March 20, as a blaze engulfed an electrical substation in Hayes, west London, cutting the power supply and backup system for Europe's busiest and the world's fifth-busiest airport.

Airline experts said the last time European airports experienced a disruption on such a large scale was when the 2010 Icelandic ash cloud grounded some 100,000 flights.

The industry is now facing the prospect of a financial hit costing tens of millions of pounds.

"You would think they would have significant backup power," one top executive from a European airline told Reuters.

The fire brigade said the cause of the fire was not known, but that 25,000 litres of cooling oil in the transformer had caught fire. It had brought the blaze under control by the early morning, with the transformer doused in white firefighting foam.

Energy Minister Ed Miliband said it did not appear to be foul play.

Heathrow had been due to handle 1,351 flights on March 21, flying up to 291,000 passengers.

The closure forced flights to divert to other airports in Britain and across Europe, while many long-haul flights simply returned to their point of departure.