The UK's skies have reopened but the row over flying restrictions caused by the volcanic ash cloud continues.
With many Britons still stranded abroad, airlines scrambled to reschedule flights amid warnings that it could be weeks before services returned to normal, .
The Civil Aviation Authority (CAA) described the chaos as a "a situation without precedent" as it moved to ease restrictions on Tuesday night.
In a crisis thought to have cost the industry about £130 million a day, it is estimated hundreds of thousands of passengers were left stranded abroad.
Willie Walsh, chief executive of British Airways, said "lessons can be learned" from the handling of the event and added: "I don't believe it was necessary to impose a blanket ban on all UK airspace last Thursday."
Air traffic control company Nats insisted it faced no political pressure to ease the restrictions. Spokesman Alex Bristol said: "We don't feel we have been under pressure from the Government. Where the pressure has come has been to better understand the safety implications."
A spokesman for BAA, which operates airports including Heathrow, said it would do everything possible to "get people moving".
"We are ready to open, but until further notice passengers must contact their airline before travelling to the airport," the spokesman said.
"Not all flights will operate during the early period of opening, and we will do everything we can to support airlines and get people moving."
© Press Association 2010