By Peter Griffiths
LONDON (Reuters) - European airports started to return to life on Tuesday after five days cut off from the rest of the world by a huge ash cloud, but some airspace stayed closed after reports a new plume from Iceland may be on its way.
Italy, Switzerland and France reopened their airports early on Tuesday though many flights remained cancelled, and in Italy only a handful took off in the morning, mainly domestic flights. Hungary, Slovenia and Moldova also resumed flights.
But the National Air Traffic Service, which controls UK airspace, said much of Britain would remain closed to flights below 20,000 feet (6,000 metres) until at least 1 a.m. British time after air traffic controllers warned a new ash cloud was headed for major air routes.
That included Heathrow, Europe's busiest airport, but not airports in the north. Airspace in Finland, Poland and parts of Sweden and Ireland was also closed.
European aviation control agency Eurocontrol said on Tuesday about half of scheduled air traffic in Europe was expected to operate -- about 14,000 flights -- up from a third on Monday.
The European Union, which announced on Monday that its members had reached a deal to reduce the size of the no-fly zone from 7 a.m. British time on Tuesday, acknowledged progress was slow.
"We know there are still a lot of problems for passengers on the ground," spokeswoman for the executive European Commission Helen Kearns told a briefing.
"We are faced with an unprecedented crisis. The disruption will continue over the week."
Germany said it would maintain its no-fly zone until 7 p.m. British time, with exceptions.
Some airlines were taking advantage of the exceptions to fly. Flag carrier Lufthansa, for example, was flying on sight, which does not require air traffic control approval, to destinations like Seoul, New York and Lagos.
"We are operating about 200 flights today. That is the bulk of our long-haul flights, and domestic and European routes are significantly expanded today," said spokeswoman Claudia Lange.
Monday's EU agreement followed enormous pressure from airlines losing an estimated $250 million (162.7 million pounds) a day.
"We were quite dissatisfied with the process that brought us here," IATA spokesman Anthony Concil said of the delay before the EU ministers' deal.
"We need to find a better way for decision-making. Nonetheless, yesterday was a step in the right direction."
MAKING THE BEST OF IT
The unprecedented disaster has stranded millions of people at the end of the busy Easter holiday season and one analyst estimated it could end up costing global passenger airlines and cargo companies as much as $3 billion.
Many travellers have spent the past five days desperately trying to get home for school or work by road, rail and sea.
British businessman Chris Thomas, trying to get home from Los Angeles since Thursday, flew to Mexico City and then aimed to fly to Madrid and spend $2,000 to rent a car for the 14-hour drive to Paris. He was booked on the Eurostar Channel tunnel train to London, and then planned to drive four hours to Wales.
"It's all a bit crazy but you have to err on the side of caution," Thomas said. "Nobody wants to be on the first plane to go down in a volcanic cloud."
Gillian and Craig Robertson from Kilmarnock in Scotland were stranded in southern Turkey with their four-year-old son Jack and would likely miss a family wedding. Robertson said he feared for his family-run business.
"We're in construction -- house building," he told Reuters. "So we've already been hit hard by the recession. With this on top, it's dreadful. This is sink or swim for us."
Others were making the best of a bad business.
"There are much worse places than that to be stuck so we had a pretty good time," said a visitor to Paris who only gave his name as Gabriel. He arrived last Tuesday and was supposed to fly back to New York on Friday.
"Not knowing when you would get back, that was a problem," he said at Orly airport. "Otherwise we made the best of it, had great food and great wine."
Britain was deploying three navy ships, including an aircraft carrier, to bring its citizens home from continental Europe. The British travel agents' association ABTA estimated 150,000 Britons were stranded abroad. Washington said it was trying to help 40,000 Americans stuck in Britain.
A British embassy official said the HMS Albion left the northern Spanish port of Santander at 12 p.m. British time on Tuesday with just under 300 British nationals and 450 troops on board. Only a handful of people were left behind with arrangements in hand to get on the next ferry.
MORE ASH ON ITS WAY?
Britain's NATS said in an overnight statement that the volcano eruption was strengthening and a new ash cloud was spreading south and east towards Britain.
"This demonstrates the dynamic and rapidly changing conditions in which we are working," it said.
The meteorological office in Iceland said although the volcano was still erupting steadily under the Eyjafjallajokull glacier about 120 km (75 miles) southeast of the capital Reykjavik, it was actually emitting less ash and more lava than previously, creating a lower cloud.
The office's Gudrun Nina Peterson said the ash heading towards Britain had probably been spewed out before conditions changed.
"If there has been ash detected over England today or during the night that is going to be from about 24 hours earlier. This is not an instant thing," she said.
An expert from the World Meteorological Organisation said in Geneva on Tuesday a low pressure weather system moving into Iceland should help clear the ash cloud within days.
"From a meteorological point of view, (for) the second part of the week towards the weekend, all indications are very, very positive," the WMO's Herbert Puempel told journalists.
Rains should help wash away ash particles seen as dangerous to aircraft and the remaining cloud should disperse towards the Arctic, according to weather forecasts, Puempel said.
Experts have disagreed over how to measure the ash and who should decide it is safe to fly. A British Airways jet lost power in all four engines after flying through an ash cloud above the Indian Ocean in 1982.
Several airlines were conducting test flights on Tuesday to gather details and data. European planemaker Airbus said it took advantage of scheduled test flights on Monday to check for the impact of ash and found nothing abnormal.
ECONOMIC IMPACT
IATA officials said the economic impact on aviation of the disaster was greater than after the September 11 attacks on the United States.
Firms dependent on air freight have felt the strain, and many businesses have had to find alternative ways of operating. Communications provider Cisco Systems said companies were turning to videoconferencing to connect executives.
(Additional reporting by European and Asian bureaux; Writing by Sonya Hepinstall; Editing by Charles Dick)
