London's Heathrow airport, one of the world's busiest travel hubs, has re-opened for landings after a six-day air travel freeze across most of Europe that grounded some 95,000 flights.<br /><br />European authorities say many more airports across the continent are set to reopen on Wednesday.<br /><br />But the ash clouds are still visible and shows no sign of letting up as wind currents move it across the UK. Technical experts say it still represents a real danger to aircraft in the sky.<br /><br />For now, though, airlines are celebrating a breakthrough allowing them to bring passengers home and stem losses which could top $1bn.<br /><br />Al Jazeera's Imran Khan reports from Heathrow airport in London.
