April 20, 2010 3:00 am

Officials admit flaws in flight ban as new cloud threatens reopening of skies

Fresh uncertainty over the resumption of flights at UK airports emerged last night after warnings that a new ash cloud was spreading towards Britain.

The move came hours after authorities across Europe agreed to ease the no-fly zone that has paralysed continental airports since last Thursday.

Earlier, officials acknow-ledged flaws in computer models that led to the most sweeping airspace closures since the second world war.

Amid mounting pressure from airlines, which have been losing an estimated $200m (£130m) a day in revenue, European Union transport ministers said they planned to start opening air corridors to bring home some of the hundreds of thousands of people stranded by the disruption that followed last week's eruption at the Eyjafjallajökull volcano in Iceland.

However, last night a Met Office spokesman said the eruptions had intensified. "This just shows how much we are at the mercy of the volcano," he said.

National Air Traffic Services, said Scottish airports should still open from 7am today and airspace over England may become available from 1pm, "although not as far south as the main London airports".

British Airways, Virgin Atlantic and other UK airlines said they intended to resume some flights today after ministers reached a deal to cut the size of the no-fly zone that has affected nearly 7m people worldwide.

Michael O'Leary, Ryanair chief executive, said he hoped to resume flights from about lunchtime tomorrow and estimated the backlog of flights would clear in "a day or two".

Plans for the reopening came after the UK deployed the Royal Navy to rescue stranded passengers and the chief executives of eight airlines wrote to the government to warn the situation had become "untenable" and "could have a material impact on our financial positions".

They said: "We believe the nature of this natural disaster presents a clear case for government compensation."

The letter came as officials in Brussels said many of the estimated 82,000 European flights grounded by air traffic authorities would have gone ahead under US aviation standards.

"The science behind the model we're running at the moment is based on certain assumptions where we do not have clear scientific evidence. It is a black box in certain areas," said Matthias Ruete, the European Commission's director-general for mobility and transport.

Mr Ruete said authorities were unsure what density of ash was hazardous for aircraft engines. Early results of 40 or so test flights conducted over the weekend by European airlines suggested risks were less than the computer models indicated.

The admission is likely to bolster critics, who accused authorities of excessive caution.

Volcanic disruption, Pages 6-7 Editorial Comment, Page 14 Gideon Rachman, Page 15 Lombard, Page 20 Markets, Pages 34-36

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