<p>London: London's Heathrow Airport said on Friday it was resuming flights after a fire at a substation knocked out its power, and it expected to run a full operation on Saturday.</p><p>Experts were in shock at the scale of the outage, which has not been seen since the Icelandic ash cloud of 2010. Heathrow processes around 1,300 flights a day.</p>
<p>London: London's Heathrow Airport said on Friday it was resuming flights after a fire at a substation knocked out its power, and it expected to run a full operation on Saturday.</p><p>Experts were in shock at the scale of the outage, which has not been seen since the Icelandic ash cloud of 2010. Heathrow processes around 1,300 flights a day.</p>