Virtually all of Europe's major airports remain closed as a huge plume of volcanic ash drifts south and east across the continent from Iceland.
Millions of air travellers are stranded as thousands of flights are being cancelled for a third day.
The disruption from the spread of ash would continue into Sunday, European aviation agency Eurocontrol said.
Airlines are losing some £130m ($200m) a day in an unprecedented shutdown of commercial air travel.
"Forecasts suggest that the cloud of volcanic ash will persist and that the impact will continue for at least the next 24 hours," a statement from Eurocontrol said at around 0830 GMT.
The agency, which co-ordinates air traffic control in 38 nations, said it expected 16,000 flights to be cancelled across Europe on Saturday, from a total of 22,000 on a normal Saturday.
Many countries and airlines have grounded fleets as the ash - a mixture of glass, sand and rock particles, drifting from 5,000ft (1,500m) - can seriously damage aircraft engines.
Some 18,000 of the 28,000 daily flights in the affected zone were cancelled on Friday, twice as many as the day before.