Europe «

Iceland’s volcano began erupting Wednesday, sending ash several kilometres in the air [Reuters]

A huge cloud of volcanic ash has tightened its grip over Europe’s skies, paralysing air travel across much of the continent and stranding thousands of travellers for a fourth day.

About 30 countries had closed or restricted their airspace by Sunday afternoon, as the cloud of fine mineral dust particles gradually expanded over large swathes of Europe.

Flights remained grounded in several countries across the continent, including the UK, France, Denmark and Germany, with some extending the airspace restrictions until at least Monday.

Aviation officials warned that airplane engines could become clogged with the tiny particles of rock and glass spewed out by the Eyjafjallajokull volcano in Iceland – though almost invisible to the naked eye – if pilots attempt to fly through the dust.

But at least two major European airlines said they had carried out successful test flights through the cloud of ash, with one, the Dutch airliner KLM, urging traffic controllers to allow commercial flights to permanently return to the skies.

‘Successful’ test flight

KLM authorities pressed for air traffic to resume on Sunday after conducting a test flight above Dutch airspace a day earlier. Dutch officials said initial inspections showed the flight had ended “safely” with “no irregularities” from the ash.
The airline said it now plans to return seven airplanes without passengers to Amsterdam from Duesseldorf on Sunday.

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

“We hope to receive permission as soon as possible after that to start up our operation and to transport our passengers to their destinations.”

Also on Saturday, Germany’s Lufthansa airlines flew 10 empty long-haul planes to Frankfurt from Munich at low altitude levels between 3,000 and 8,000 metres, Wolfgang Weber, a spokesman, said.

“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,” he said.

“Not the slightest scratch was found on any of the 10 planes.”

‘Global experiment’

Italian and French carriers also announced that they would be flying empty airliners on Sunday to assess conditions.

But David Learmount, the operations and safety editor of Flight International magazine and a former Royal Air Force pilot, said putting planes back into the air is unchartered territory.

“We are going through a global experiment,” he told Al Jazeera.

“What we don’t know is about what Europe is suffering at the moment, which is low intensity, widely spread ash. What KLM has found out is that the damage may be relatively insignificant.

“But if the efficiency of the engines is downgraded by abrasion of the fan blades, that can downgrade the efficiency of the engine, which will mean that for the rest of that engine’s life it will be using more fuel than it otherwise would have done.

“So to get airborne a couple of days earlier, you might pay the price of it for the rest of that aircraft’s life.”

‘No end in sight’

The Eyjafjallajokull volcano began erupting on Wednesday, sending ash several kilometres into the air, and generating a plume of particles.

Meteorologists have said light prevailing winds in Europe and the large amounts of glacial ice above the volcano mean the cloud is unlikely to move far until later in the week.

“There doesn’t seem to be an end in sight,” Magnus Tumi Gudmundsson, an Icelandic geologist monitoring the volcano, said on Saturday.

“The activity has been quite vigorous…, causing the eruption column to grow,” he told the Associated Press.

Graeme Leitch, a meteorologist at Britain’s National Weather Service, said forecasters do not expect a great deal of change over the next few days.

“Currently the UK and much of Europe is under the influence of high pressure, which means winds are relatively light and the dispersal of the cloud is slow,” he said.

Scientists say that because the volcano is situated below a glacier, the magma is being cooled quickly, causing explosions and plumes of fine grit to be ejected high into the atmosphere.

Financial impact

The cloud has also caused several world leaders to rearrange travel plans.

The airspace closure stopped Barack Obama, the US president, from flying to the southern Polish city of Krakow for the funeral of Lech Kaczynski, Poland’s president, and his wife, Maria.

The Kaczynski couple were among 96 people, most of them senior Polish government figures, killed in a plane crash in Russia on April 10 on their way to a World War II memorial service.

Authorities have permitted some low-level flights in the south of Poland, however, to allow the Polish Air Force to ferry the Kaczynski’s coffins from Warsaw to Krakow aboard a propeller-powered military cargo plane.

But as the grounding continues elsewhere, the airline industry, still reeling from the impact of the global financial crisis, is facing daily losses of at least $200m, the International Air Transport Association has said.

And with little sign of when the ash will clear, some airlines have said they may have to consider job lay-offs and other measures to deal with the financial impact.

Al Jazeera’s David Chater, reporting from southern Iceland close to the volcano, said that the simple fact was that nobody knows how long the eruption will last.

He said it was a real crisis for the aviation industry, but also for the people living near the slopes of the volcano whose land and farm animals are being poisoned by the thick clouds of ash.

“Vulcanology is a complex science, but it is not an exact science,” he said.

“We’ll just have to wait and see.”