British civil aviation authorities ordered the closure of the country’s airspace as of noon on Thursday to shield aircraft from a high altitude cloud of ash drifting south and east from an erupting volcano in Iceland.
The plume of ash shut down airports and forced the cancellation of hundreds of flights in a wide arc from Ireland to Scandinavia.
The closures left airplanes on the tarmac as the rolling cloud — made up of minute particles of silicate that can damage airplane engines — headed from Britain and Scandinavia toward northern France. News reports said Denmark also had restricted air travel.
“From midday today until at least 6 p.m., there will be no flights permitted in U.K. controlled airspace other than emergency situations,” Britain’s National Air Traffic Service said in a statementon its Web site. “This has been applied in accordance with international civil aviation policy.”
The move effectively grounded all flights in Britain from 11:00 a.m. Greenwich Mean Time (7:00 a.m. Eastern) and affected an estimated 6,000 flights that use British airspace every day, aviation experts said.
Oddly, for travelers, the closure was announced under clear blue skies. Experts had said earlier that the ash may not be visible from the ground but can clog airplane engines.