A cloud of volcanic ash from Grimsvotn volcano obscures houses in the village of Vik, in Myraldur, Iceland, on May 23 and is now headed toward Ireland. (Ragnar Axelsson/Bloomberg)

And they aren’t too pleased about it.

Irish budget airline Ryanair insisted that it had sent its own airplane into Scottish airspace and found no ash in the atmosphere. There is “no basis for these cancellations,” Ryanair wrote in a note on its Web site

The ash cloud has already forced President Obama to shorten a visit to Ireland on Monday, and raised fears of a repeat of the huge travel disruptions Europe experienced last year when ash from another Iceland volcanic eruption stranded millions of passengers.

An arrivals flight information board showing cancelled flights from Scotland is pictured at Dublin International airport in Ireland, on May 24, 2011. (Peter Muhly/AFP/Getty Images)

Experts say that particles in the ash were dangerous because they could stall jet engines and sandblast planes’ windows.

Aer Lingus seemed happy to avoid that scary scenario, canceling 20 flights between Ireland and Scotland.

“We take the advice given to us,” Aer Lingus spokesman Declan Kearney said. “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.”