LONDON - Two of Europe's busiest airports closed early Monday morning as a dense cloud of volcanic ash drifted from Iceland, aviation authorities said. The airspace over London's Heathrow Airport closed on Monday, Britain's National Air Traffic Service said in a statement late Sunday night. In Amsterdam, Schiphol Airport, another of Europe's biggest air travel hubs, was closed until 2 p.m. local time Monday, a statement on Dutch airline KLM's website said. The restrictions affecting Heathrow - as well as Gatwick, Stansted and London City airports - will be in place until at least 7 a.m. local time (06:00 GMT) Monday, the aviation authority said. Airports across Britain and Ireland were closed for much of Sunday because of the drifting ash. The shifting of the no-fly zone southward will allow airports in northern England - including the key cities of Manchester and Liverpool - to reopen after 1 a.m. local time. But all airports in Northern Ireland, as well as some Scottish facilities, will remain shut. In Ireland, Dublin's international airport closed early Sunday evening until at least 12pm Monday (11:00 GMT, 7am EDT). Some airports in Ireland's west were closed and will reopen at different times Monday, but Shannon and southern Cork were open "until further notice." The British air traffic agency said the ash cloud was changing shape and moving south, toward Oxford, England, 60 miles (100 kilometres) northwest of London. Britain's weather service says the northwest winds should shift midweek, redirecting the ash away from Britain. German authorities sent up two test flights Sunday to measure the ash cloud, one from the German Aerospace Center (DLR) and the other from Lufthansa, the country's biggest airline. The DLR plane flew to southern England then continued north, collecting data from between 10,000 to 23,000 feet (3,000 to 7,000 meters). The Lufthansa Airbus A340-600, equipped with special scientific gear, left Frankfurt to fly over northern Germany, the United Kingdom and parts of Scandinavia. All the data from both flights was immediately sent to aviation authorities in the U.K, the Netherlands and Germany, said aerospace center spokesman Andreas Schuetz. Ash can clog jet engines. The April 14 eruption at Iceland's Eyjafjallajokul volcano forced most countries in northern Europe to shut their airspace between April 15-20, grounding more than 100,000 flights and an estimated 10 million travellers worldwide. The shutdown cost airlines more than $2 billion. In southern Iceland, activity at the volcano fluctuated Sunday but did not get more intense, civil protection official Agust Gunnar Gylfason said. He blamed the closures on shifting winds. "What really changes the situation is the weather pattern," he said. The Icelandic weather service said "presently there are no indications that the eruption is about to end." Airlines complained bitterly over the air space closures last month, calling them an overreaction. The European air safety agency last week proposed drastically narrowing the continent's no-fly zone because of volcanic ash to 120 miles (190 kilometers) like the one used in the U.S. The proposal still must be approved. Virgin Atlantic's president, Sir Richard Branson, criticized British authorities for Sunday's no-fly zone. British Airways agreed, calling the approach "overly restrictive and not justified on safety grounds" and saying airlines are best qualified to determine whether it's safe to fly. "The closing of Manchester airspace once again is beyond a joke," Branson said in a statement. He said test flights have "shown no evidence that airlines could not continue to fly completely safely."
