European flights could resume Monday

Europeanofficials are expressing optimism that more flights could be in the air over the continentMonday, after volcanic ash from Iceland forced five consecutive days of widespread cancellations.

EU Transport Commissioner Siim Kallas said it's possible that almost 50 per cent of flights in Europe could operate on Monday.

The current situation is "not sustainable," Kallas told reportersat a briefing held Sunday in Brussels by the European air traffic authority, Eurocontrol.

More than three quarters of flights in European airspace have been grounded over fears the cloud of ash could stall aircraft engines, and the disruption has leftmillions of passsengersstranded in northern and central Europe andoverseas.

Diego Lopez Garrido, Spain's secretary of state for European Union affairs, said EU transport ministers will meet on Monday to "take into account technical advice" including results of newly conducted test flights.

Dutch airline KLM said it safely flew aircraft without passengers through a window in the cloud of volcanic ash over Europe Sunday, and pressed for an end to the total ban on commercial air traffic.

Other airlines including Lufthansa and Air France said they, too, were conducting test flights. Authorities, however, extended airspace restrictions across Europe and said there was no end in sight to the ash plume.

KLM said the planes, of various types in its fleet, flew at normal altitude above 10,000 feet but did not encounter the thick cloud that had hovered over the continent since Wednesday, apparently indicating thatthe Icelandic dust had thinned or dispersed.

A KLM spokeswoman said four aircraft completeda short flight from Duesseldorf in western Germany without incident and four more planes were due to return to their home base at Schiphol Airport.

The airlinereceivedpermission from Dutch and European aviation authorities before sending the planes aloft. Engineers immediately took the aircraft for inspection as they landed.

'In our opinion, there is absolutely no reason to worry about resuming flights.' Steven Verhagen, vice-president of the Dutch Airline Pilots' Association

Steven Verhagen, vice-president of the Dutch Airline Pilots' Association and a Boeing 737 pilot for KLM, said he would have no qualms about flying today and his 4,000-member organization was calling for a resumption of flights.

"With the weather we are encountering now clear blue skies and obviously no dense ash cloud to be seen, in our opinion there is absolutely no reason to worry about resuming flights," he said.

"We are asking the authorities to really have a good look at the situation, because 100 per cent safety does not exist," Verhagen said. "It's easy to close down airspace because then it's perfectly safe. But at some time you have to resume flights."

Continued caution over unstable winds

But meteorologists said the situation above Europe was unstable and constantly changing with the varying winds and the unpredictability was compounded by the volcano's irregular eruptions spitting more ash into the sky.

The cloud "won't be present at all parts of the area at risk at all times, you can see clear area, but it will change, it won't stand still," said John Hammond of the British Meteorological Office.

Millions of passengers have had plans foiled or delayed because of a ban on air travel that has gradually expanded over large swaths of Europe since Thursday.

The aviation industry, already reeling from a punishing economic period, is facing at least $200 million in losses every day, according to the International Air Transport Association.

KLM, a subsidiary of Air France, began test flights Saturday with a Boeing 737 flying up to 41,000 feet (13,000 metres), the maximum altitude at which the aircraft is certified to fly.

"We observed no irregularities either during the flight or during the initial inspection on the ground," said chief executive Peter Hartman, who was aboard Saturday's flight.

KLM aircraft with no passengers to fly from Duesseldorf

The airline planned to return seven airplanes without passengers to Amsterdam from Duesseldorf on Sunday.

"We hope to receive permission as soon as possible after that to start up our operation and to transport our passengers to their destinations," Hartman said in a statement.

German airlines also conducted flights, but at a lower altitude. German restrictions allow such flights,as long as no passengers are on board.

Lufthansa flew 10 empty long-haul planes to Frankfurt from Munich at heights of between 9,800 and 26,200 feet (3,000 to 8,000 metres) Saturday under so-called visual flight rules, in which pilots don't have to rely on their instruments, spokesman Wolfgang Weber said.

He stressed that the flights weren't tests, and were merely intended to get the planes in the right place at the Frankfurt hub for when restrictions are lifted.

"We simply checked every single aircraft very carefully after the landing in Frankfurt to see whether there was any damage that could have been caused by volcanic ash," Weber said. "Not the slightest scratch was found on any of the 10 planes."

German air traffic control said Air Berlin and Condor had carried out similar flights.

Air Berlin, Germany's second-biggest airline, said it had transferred two planes from Munich to Duesseldorf and another from Nuremberg to Hamburg without problems on Saturday. They flew at 9,840 feet (3,000 metres).

Similar findings with German airliners

A technical inspection of the aircraft after landing "did not reveal any adverse effects," the company said.

Air Berlin chief executive Joachim Hunold declared himself "amazed" that the results of the German airlines' flights "did not have any influence whatsoever on the decisions taken by the aviation safety authorities."

Kyla Evans, spokeswoman for the European air traffic control agency Eurocontrol, said it was up to national aviation authorities to decide whether to open up their airspace. The agency's role was to co-ordinate traffic once it was allowed to resume.

Scientists say that because the volcano is situated below a glacial ice cap, magma is being cooled quickly, causing explosions and plumes of grit that can be catastrophic to plane engines, depending on prevailing winds.

"Normally, a volcano spews out ash to begin with and then it changes into lava, but here it continues to spew out ash, because of the glacier," said Reynir Bodvarsson, director of the Swedish National Seismic Network. "It is very special."