A huge ash cloud from an Icelandic volcano spread out across Europe today causing air travel chaos on a scale not seen since the September 11th attacks.
About 17,000 flights were expected to be cancelled today due to the dangers posed for a second day by volcanic ash from Iceland, aviation officials said.
Airports in Britain, France, Germany, and across Europe were closed until at least tomorrow.
Britain's airspace will remain restricted until at least 1 pm tomorrow National Air Traffic Services said.
Of the 28,000 flights that usually travel through European airspace on an average day, European aviation control agency Eurocontrol said it expected only 11,000 to operate on Friday while only about a third of transatlantic flights were arriving.
The volcano began erupting on Wednesday for the second time in a month from below the Eyjafjallajokull glacier, hurling a plume of ash 11km into the atmosphere.
Officials said it was still spewing magma and although the eruption could abate in the coming days, ash would continue drifting into the skies of Europe. Volcanic ash contains tiny particles of glass and pulverised rock that can damage engines and airframes.
"I would think Europe was probably experiencing its greatest disruption to air travel since 9/11," said a spokesman for Britain’s Civil Aviation Authority. "In terms of closure of airspace, this is worse than after 9/11. The disruption is probably larger than anything we've probably seen."
Following the September 11th, 2001 attacks in the US, US airspace was closed for three days and European airlines were forced to halt all transatlantic services.
Vulcanologists say the ash could cause problems to air traffic for up to six months if the eruption continues, but even if it is short-lived the financial impact on airlines could be significant.
The British Meteorological Office showed the cloud drifting south and west over Europe. Eurocontrol warned problems would continue for at least another 24 hours and an aviation expert at the World Meteorological Organisation said it was impossible to say when flights would resume.
"We can only predict the time that flights will resume after the eruption has stopped, but for as long as the eruption is still going on and still leading to a significant eruption, we cannot say," said Scylla Sillayo, a senior official in the WMO's aeronautical meteorology unit.
There were no flights from London's Heathrow, Europe's busiest airport, which handles some 180,000 passengers a day, while flights were suspended at Germany's Frankfurt airport, Europe's second busiest.
Around 2,000 people slept overnight at Amsterdam's Schiphol Airport, a spokeswoman said, adding they did not expect airspace in the Netherlands to reopen soon.
Eurocontrol said airspace was closed over Belgium, Denmark, Sweden, Norway, Finland, Estonia, the north of the Czech Republic, northern France including all Paris airports, and at airports in northern Germany, Austria and parts of Poland.
German chancellor Angela Merkel's government Airbus was diverted to land in Portugal as she returned to Germany from the United States. Ms Merkel will now spend the night in the Portuguese capital, a spokesman said. With Germany's main airports closed because of the ash, it was also unclear where Defence Minister Karl-Theodor zu Guttenberg, who is returning from Afghanistan, will land.
Airlines across Asia and the Middle East have also cancelled or delayed flights to most European destinations.
However, as the ash plume drifted south over Europe, Irish officials said most of the airspace over Ireland had reopened.
The fallout hit airlines' shares today with Lufthansa, British Airways, Air Berlin, Air France-KLM, Iberia and Ryanair down between 0.8 and 2.2 per cent. The International Air Transport Association said only days ago that airlines were just coming out of recession.
However, the air problems have proved a boon for rail companies. All 58 Eurostar trains between Britain and Europe were operating full, carrying some 46,500 passengers, and a spokeswoman said they would consider adding services if problems persisted.