The European air traffic control monitoring agency Eurocontrol says flight schedules are back to normal. Between 28,000 and 29,000 flights were taking off as expected on Thursday, the organization said, representing normal traffic levels.

Air hubs across Europe were reopened at close to full capacity, although a plume of ash over Scandinavia caused some new closures.

Flights across Europe had been suspended after fear that ash from the volcano under the Eyjafjallajoekull glacier could turn into a glassy substance inside jet engines, and damage them.

According to the German association of airports, ADV, since the start of the airport closures last Thursday, three million passengers have had their flights cancelled. More than half of the 190,000 flights scheduled to take off in Europe over the last week were cancelled, Eurocontrol said.

The delays left passengers stranded at airports and led to a boost in train and ferry travel as people tried to find alternative routes to their destinations.

With airports and airlines now open for business, it is estimated it could take days, or even weeks to clear the backlog of passengers.

Economic impact

The International Air Transport Association (IATA) said the ban on flying cost its member airlines 1.3 billion euros ($1.7 billion). Air carriers are now considering whether to turn to governments for compensation.

"For an industry that lost $9.4 billion last year and was forecast to lose a further $2.8 billion in 2010, this crisis is devastating," IATA Director-General and Chief Executive Giovanni Bisignani said in a statement.

Many airlines have been highly critical of European governments, claiming their response to the crisis was a costly overreaction.

However, German Transport Minister Peter Ramsauer defended the measures, saying that safety had to come first.

The volcano was still erupting on Thursday, but producing much less ash. Meterorlogists said the ash had now blown into the northern Atlantic between Iceland, Norway and Scotland.

Wind swept a fresh plume of ash over Scandinavia, bringing about renewed closures. Helsinki's international airport and Gothenberg airport in Sweden had to be closed to flights but were later repoened.

cb/dpa/AP/Reuters
Editor: Chuck Penfold