UK airspace will be free of a dense volcanic cloud for the rest of the week, allowing the half-term getaway to begin without threat of disruption, according to the latest forecasts.
The Met Office believes that projections showing a heavy cloud of ash blanketing the UK on Friday are no longer valid because the Grímsvötn crater in Iceland is now emitting only steam as the eruption subsides. The information emerged in a conference call involving the UK aviation industry on Wednesday afternoon and the national weather forecaster is expected to produce a new, detailed forecast later this evening.
According to an aviation industry source, the latest development has headed off a potentially embarrassing development for the Met Office and the UK Civil Aviation Authority (CAA) on Friday.
If the previous forecast had remained unchanged, US and middle eastern airlines would have taken off and landed in the UK on Friday anyway because they do not use Met Office forecasts and their charts – produced by the WSI corporation – apparently showed no high density ash over the UK.
This could have resulted in British Airways and Virgin Atlantic flights being grounded while Emirates and American Airlines services took off and landed.
The news comes as UK airlines return to normal operation following severe disruption to flights in Scotland earlier this week. The head of British Airways and Iberia joined the clamour over the handling of the volcanic ash cloud after claiming that a BA test flight "found nothing" after flying through a smoke plume deemed by regulators to be too dangerous for normal commercial flights.
Echoing criticism from Ryanair, Willie Walsh said the plane flew through an ash "red zone" for 45 minutes over Scotland and northern England on Tuesday and encountered no difficulties. The chief executive of International Airlines Group, the parent of Britain and Spain's national carrier, spoke as the cloud from the Grímsvötn volcano moved away from UK airspace and began to affect travel in Germany this morning.
Walsh told BBC Radio 4's Today programme that the flight operated at different altitudes, through a zone designated by the Met Office to contain high densities of ash – a level at which no commercial carrier has received safety clearance to operate. "Initially it flew over the north of England, Newcastle, Glasgow, Edinburgh, back to Newcastle. The aircraft then returned and has been examined. All the filters were removed and will be sent to a laboratory for testing. The simple answer is that we found nothing."
Philip Hammond, the transport secretary, defended the new ash regulations, which use Met Office forecasts to place ash clouds into three categories: low, medium and high. Airlines must produce safety cases, vetted by the UK CAA , to prove which density they can fly through. Currently, all UK airlines are clear to fly through the medium zones that have drifted across much of British airspace in recent days, but none have clearance to go through the high density "red zone" that has hit services in Scotland and has been the target of BA and Ryanair test flights.
Speaking on BBC Breakfast News, Hammond said the Met Office models could not be 100% accurate and the BA flight did not necessarily contradict the regime. He added: "The red zone is not indicating that every square inch of air within that zone … contains a high density of ash. This is a modelled zone in which concentrations of ash at dangerous levels may exist. So it will be perfectly compatible with that model that an aircraft could fly through that zone and not encounter ash, but another aircraft could fly through on a different track and encounter high levels of ash."
About 500 flights were halted – and others delayed – across Europe on Tuesday as the eruption of Grímsvötn volcano in Iceland caused havoc at airports in Scotland and northern England.
Last night the Met Office had forecast a plume of high density ash over the UK on Friday, at a height of 35,000ft and above. This prompted the CAA to look at changing the ash regulations just in case a cloud hits the UK at 35,000ft on Friday. Current rules prevent "underflying" the cloud even though 35,000ft is roughly the maximum cruising height for airlines. This would prevent aircraft at Heathrow and other major airports taking off and landing even though they would not reach the cloud's altitude while in the area.
The government is also seeking to borrow an atmosphere monitoring plane from Ireland or Germany because the one it has ordered – specifically for ash purposes – will not be ready until July. On Tuesday the International Air Transport Association wrote to Hammond bemoaning the lack of monitoring aircraft. In the meantime the UK government is co-operating with commercial carriers such as BA to monitor the cloud.
The ash cloud ruined the plans of thousands of travellers travelling to and from northern Germany, when airports in Bremen, Hamburg and Berlin were shut as a safety precaution, hitting flights operated by BA, BMI, easyJet and Ryanair.
The flight ban issued for Hamburg and Bremen was lifted at midday after six hours. It remained in place for Berlin's two airports, Tegel and Schönefeld, which were closed between 11am and 2pm local time, the German air traffic control authority said.
Flights from Frankfurt were also affected, with domestic passengers for affected Lufthansa flights being given replacement rail tickets where possible. There were knock-on effects for travellers in the southern airports of Stuttgart, Munich and Nuremberg.
The closures caused anger among many passengers who thought they were unnecessary. This belief seemed to be confirmed when the scientific research centre Jülich issued a statement saying the concentration of ash in the current cloud appeared much lower than last year.
"If you look at the pictures we took last year, you can tell the concentration [of ash] is not as high," said Cornelius Schiller, after Jülich took measurements with their laser system, Lidar, in Schleswig-Holstein. But he said it was difficult to ascertain how much of a threat the current cloud posed. "We need to look closer at our data for that," he said.
In an interview on German TV on Wednesday morning, the German transport minister, Peter Ramsauer, insisted there was a "solid legal basis" for the flight ban, which has been criticised as too draconian by airlines.
Other European countries have adopted the German guideline of banning flights when the concentration of ash exceeds 2mg per cubic metre. "Safety comes first," Ramsauer told the public ARD TV network on Wednesday morning.
The number of German flights affected was not clear, but aviation authorities said at least 270 flights were cancelled in Bremen and Hamburg alone.
