About 80 percent of flights in Europe were expected to have taken place on Wednesday while Thursday’s level will be almost 100 percent, European air traffic agency Eurocontrol said.
Wednesday’s total was 22,500 flights compared with about 28,000 that would normally be scheduled, it said, adding trans-atlantic flights had returned to normal.
Flights resumed after scientists and manufacturers downgraded the risk of flying in areas of relatively low ash concentrations, Britain’s Civil Aviation Authority said.
“The major barrier to resuming flight has been understanding tolerance levels of aircraft to ash. Manufacturers have now agreed increased tolerance levels in low ash density areas,” CAA head Deidre Hutton said.
“A return to normal will take another 48 hours,” French junior Transport Minister Dominique Bussereau predicted. “I think the situation will be normal before the weekend.”
Britain had lagged behind its European neighbours in downgrading the threat to airplanes from the ash, which can potentially scour and even paralyse jet engines.
In 1982, a British Airways jet lost power in all four engines after flying through an ash cloud over the Indian Ocean.
“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 on Wednesday.
He urged governments to examine ways to compensate airlines.
“It is an extraordinary situation exaggerated with a poor decision-making process by national governments,” he said.
The two biggest travel companies in Europe, Thomas Cook and TUI Travel issued a joint statement criticising the British government’s response to the volcano.
“The government’s response to the crisis has been a shambles,” said TUI Travel Chief Executive Peter Long.
“It is clear that they underestimated the severity of the consequences of the decision for a blanket closure of the airspace for such a protracted period of time.”
But Henri Goudru, a UN scientific adviser who has studied volcanic eruptions for 40 years, defended the closures.
“In the absence of reliable facts, the only thing to do was to stop aircraft from flying, given the risk to planes of suffering serious engine damage, perhaps crashing,” Goudru, who is also president of the European Volcanological Society, told a news conference in Geneva.
Steve Ridgway, chief executive of Virgin Atlantic, said: “Whilst the reopening of airspace is good news both for passengers and the industry as a whole, it is likely to take several days to get everyone who has been affected to their destinations.”
For some passengers who have faced epic journeys and huge financial outlay since no-fly zones were imposed on Thursday, the decision came too late.
For Meg Newman, 31, a speech and language therapist, and Harry Speller, 30, both of London, New York was the last leg of a three-month tour through India, Nepal and Malaysia after Speller lost his accounting job.
Each budgeted 3,000 pounds for their travels, and Speller estimates the extended stay in New York will cost at least another 1,500 pounds.
“New York was our five-day treat,” Newman said. “We weren’t expecting it to be 16 days. Now we haven’t got the money.”
New York itself is losing about $3 million a day in reduced spending, according to city officials, and the Spanish tourist industry, excluding airlines, lost 252 million euros (219.9 million pounds), the nation’s tourist body said.
The economic impact of the cloud has already hit parts of the supply chain and could potentially dent the fragile recovery from the global recession.
PricewaterhouseCoopers estimated a week of disruption could destroy around 0.025-0.05 percent of annual British GDP, and the same would probably be true of other European countries. But Germany said the impact on its economy would be limited.
The volcano under the Eyjafjallajokull glacier was still erupting on Thursday, but producing much less ash.
“There is ongoing activity in the volcano and we don’t see any signs of it coming to an end. There is less ash production, it is probably the same as yesterday,” Icelandic meteorological office official Gudrun Nina Petersen told a news conference.
“The plume is very low, so most of the ash is falling here and keeping itself under 20,000 feet (6,000 metres),” she said.
A low pressure weather system moving into Iceland should also help clear the ash cloud within days, an expert from the World Meteorological Organisation said in Geneva.