500 flights could be cancelled due to ash: official

Five hundred flights could be cancelled in Northern Ireland, Scotland and parts of Scandinavia on Tuesday if clouds of volcanic ash continue to drift toward commercial airports.

The recent eruption of Iceland's Grimsvotn volcano has sent clouds of volcanic ash towards parts of Scandinavia and western Europe, which has drawn the attention of aviation authorities who are mindful of the hazards that ash causes for commercial airplanes.

Regulators have warned airlines that they must seek permission to fly to and from the areas where ash clouds are present.

Brian Flynn, the head of network operations at the European air traffic agency, said between 200 and 250 flights were cancelled on Tuesday as a result of the ash clouds.

This represents a small fraction of the 30,000 daily flights within Europe at this time of year.

While the number of cancelled flights could increase to 500 on Tuesday, Flynn said it was unlikely that the ash cloud would cause the kind of cancellations seen last year when the Eyjafjallajokull volcano erupted and thousands of flights had to be grounded.

His assessment was echoed by Siim Kallas, the European Union transportation commissioner, who said "widespread airspace closures" were not expected as a result of the Grimsvotn eruption.

The ash was not expected to affect trans-Atlantic flights, because it was floating below the altitude where airliners crossing the ocean typically cruise.

Officials take flak over handling of ash issue

The decision to ground some flights on Tuesday drew criticism from Irish budget airline Ryanair, whose chief executive Michael O'Leary suggested that aviation officials had overreacted to the Grimsvotn ash.

O'Leary claimed that Ryanair had sent its own airplane into Scottish airspace and found no ash in the atmosphere.

"Exactly as we predicted, we encountered absolutely no problems," O'Leary told The Associated Press in an interview on Tuesday.

"There's no cloud over Scotland. There's no dusting of ash on the airframe or the wings. The airspace over Scotland should never have been restricted in the first place."

The International Air Transport Association, the main international body representing air carriers, said the British government should have used Cessna planes to conduct aerial tests for ash, instead of relying on the national weather service.

But other industry voices supported the decision to be cautious in the wake of the spreading ash clouds.

"We take the advice given to us," said Declan Kearney, the spokesperson for Aer Lingus, which cancelled 20 flights between Scotland and Ireland.

"We have no reason to question the advice being given to us by the aviation authorities at this time. We need to accept what the experts in this area are telling us."

The European Cockpit Association said airlines should not allow their planes to venture into areas with even moderate ash concentrations.

Ash to affect afternoon air travel

The Grimsvotn ash was projected to reach airports in Scotland, Northern Ireland and parts of northern England by Tuesday afternoon.

Britain's National Air Traffic Services said the ash was likely to affect airports in Londonderry, Northern Ireland; Glasgow, Edinburgh and Prestwick in Scotland; and Newcastle, Carlisle, Durham Tees Valley and Cumbernauld in northern England.

Passengers in these regions were advised to check with their airlines before travelling to airports in these cities.

A separate cloud of Grimsvotn ash had moved away from the coast of Norway on Tuesday, no longer affecting the airports in Stavanger and Karmoey. But Norwegian airport operator Avinor said the ash is expected to return to southern Norway in the afternoon.

With files from The Associated Press