Airlines and airports have been warned to expect ash from an erupting Icelandic volcano to arrive in UK airspace by Tuesday, with the possibility that it could affect Heathrow airport by the end of the week.
Europe‘s air traffic control organisation, Eurocontrol, told airlines and airports on Monday that particles from the Grimsvötn volcano could reach Scotland by 1am on Tuesday and southern England by Thursday or Friday, depending on wind direction.
An aviation industry source said if the volcano continues to erupt at same intensity ash cloud could reach the west of the UK on Thursday or Friday, but the Met Office has low confidence in the forecast because of a prevailing low pressure system.
However, the Civil Aviation Authority (CAA) said it was confident that a new Europe-wide safety regime introduced after the Eyjafjallajökull eruption last year would reduce disruption significantly and avoid the continental shutdown that stranded millions.
Under previous guidelines, aeroplanes were summarily grounded if there was any volcanic ash in the air. Now, airlines can fly through ash plumes if they have a safety case demonstrating that their fleets can handle medium or high-level densities of ash.
A CAA spokesman said most major airlines already have safety cases for medium-density ash clouds.
“We are in a much better position than last time,” he said. “Safety will still be paramount but we will be able to drastically reduce disruption compared to last time, provided there is not a huge amount of high-density ash.” The spokesman said a similar level of ash to the Eyjafjallajökull incident would not result in a mass-grounding. “It will be a different picture.”
BAA, the owner of Heathrow, Stansted, Edinburgh, Glasgow and Aberdeen airports, has convened a crisis support team to prepare for a reduction in flights, as airlines and airports await a further briefing from National Air Traffic Services (Nats). “We are working closely with the CAA and Nats in preparing contingency plans if ash enters UK airspace,” it said.
Under the new ash guidelines, cloud densities are split into three levels: low; medium; and high. Once Nats assigns a particular density of ash to a section of airspace, airlines must prove that they have the safety case to fly through it. A low density cloud is 2g of ash per 10 cubic metres of air, with medium being 2g to 4g of ash per 10 cubic metres. Anything above 4g is deemed high density.
The Grimsvötn volcano began erupting on Sunday, causing flights to be cancelled at Iceland‘s main Keflavik airport after it sent a plume of ash smoke and steam 12 miles (19km) into the air. Experts have said the eruption was unlikely to have the dramatic impact that the Eyjafjallajökull volcano had in April 2010.
“At the moment if the volcano continues to erupt to the same level it has been, and is now, the UK could be at risk of seeing volcanic ash later this week,” said Helen Chivers, Met Office spokeswoman. “Quite when and how much we can’t really define at the moment.”
She said the weather situation is set to be different to last year, with the wind direction set to change continuously.
She added: “If it moves in the way that we’re currently looking, with the eruption continuing the way it is, then if the UK is at risk later this week, then France and Spain could be as well.”
While the ash has grounded aircraft in Iceland, it is not anticipated that it will have a similar impact in the rest of Europe.
Dr Dave McGarvie, volcanologist at the Open University, said that the amount of ash reaching the UK “is likely to be less than in the 2010 Eyjafjallajökull eruption”, and said the last two times Grimsvötn erupted it did not affect UK air travel.
“In addition, the experience gained from the 2010 eruption, especially by the Met Office, the airline industry, and the engine manufacturers, should mean less disruption to travellers.”
The April eruption of the Eyjafjallajökull volcano, in south-east Iceland, caused the worst disruption to international air travel since 9/11. Flights across Europe were cancelled for six-days stranding tens of thousands of people and was estimated to have cost airlines £130m a day.
Eurocontrol said in a statement: “There is currently no impact on European or transatlantic flights and the situation is expected to remain so for the next 24 hours. Aircraft operators are constantly being kept informed of the evolving situation.”