Reporting from London — More planes began taking off from airports across Europe on Tuesday after days of enforced idleness, but a new cloud of volcanic ash moving toward the continent has thrown into doubt any resumption of normal service.
Air France said it would operate all of its regularly scheduled long-haul flights out of Paris on Tuesday, as well as some shorter hops within the country and to destinations in southern Europe.
Lufthansa Airlines said it would go ahead with dozens of intercontinental flights out of various German airports, many of them bound for the U.S. The carrier said it would run some domestic routes and intra-European journeys also.
Most intercontinental flights on Dutch airline KLM were also scheduled to arrive in and depart from Amsterdam, another busy European hub.
In Britain, some flights began operating out of Northern Ireland and Scotland. But by midday Tuesday, British aviation authorities had still not granted permission for flights to and from Heathrow Airport in London, one of the world's busiest transit points, despite hopes by British Airways to resume some service Tuesday evening.
And meteorologists warned that a second cloud of ash and grit from the Eyjafjallajokull volcano in Iceland had started drifting east, which could cause mass shutdowns again.
The resumption of some flights nonetheless came as a relief to many stranded passengers, some of whom cheered in Paris when they watched a plane take off from normally bustling Charles de Gaulle Airport, the Associated Press reported.
Aviation officials said the situation was fluid and would be constantly reevaluated as winds shift and as the volcano continues to blast tiny particles of ash and glass into the atmosphere.
"There cannot be any compromise on safety," Siim Kallas, the European Commission's vice president for transport said Monday. "All our assessments … are based on expert decisions, decisions of independent bodies and science."
Officials said the slight relaxing of restrictions was due to the ash having dissipated in some places and not to any lobbying by the airline industry.
But with their companies hemorrhaging money, airline executives and trade groups have become increasingly vociferous in the last two days about what they see as an exaggerated response by aviation authorities to the dangers posed by the ash cloud.
Airlines in Britain, France, Germany and the Netherlands have conducted their own test flights to gauge conditions and declared that their aircraft suffered no damage.
"The analysis we have done so far, alongside that from other airlines' trial flights, provides fresh evidence that the current blanket restrictions on airspace are unnecessary," said British Airways CEO Willie Walsh, who participated Sunday in a test flight from London to Cardiff, Wales. "Our assessment is that the risk has been minimal and can be managed by alternative procedures to maintain the highest [safety] standards."
Giovanni Bisignani, head of the International Air Transport Assn., lambasted European officials for a lack of coordination and leadership on a crisis that was costing the airline industry as much as $200 million a day. He criticized European aviation officials' methods of calculating risk from the ash, saying they were based on theoretical models rather than facts.
"This is not an acceptable system, particularly when the consequences for safety and the economy are so large," Bisignani said.
Some European airline executives are now raising the possibility of asking for financial bailouts from their governments, as happened after the closure of U.S. airspace following the Sept. 11 attacks.
Businesses around the world have suffered losses from the lockdown on European airspace, from flower and fruit producers in Africa and Asia to German automotive companies unable to export parts. FedEx and other package-delivery services have suspended their next-day promises.
Here in Britain, meanwhile, the government announced that it would dispatch three naval warships to bring home Britons from the European mainland, including soldiers stuck in Spain after a tour of duty in Afghanistan.
Times staff writer Janet Stobart contributed to this report.