SPRAGGETT ON CHESS
Air ban led by flawed computer models
By Joshua Chaffin in Brussels
Published: April 19 2010 15:17
Last updated: April 19 2010 20:46
Flawed computer models may have exaggerated the effects of an Icelandic volcano eruption that has grounded tens of thousands of flights, stranded hundreds of thousands of passengers and cost businesses hundreds of millions of euros.
The computer models that guided decisions to impose a no-fly zone across most of Europe in recent days are based on incomplete science and limited data, according to European officials. As a result, they may have over-stated the risks to the public, needlessly grounding flights and damaging businesses.
“It is a black box in certain areas,” Matthias Ruete, the EU’s director-general for mobility and transport, said on Monday, noting that many of the assumptions in the computer models were not backed by scientific evidence.
European authorities were not sure about scientific questions, such as what concentration of ash was hazardous for jet engines, or at what rate ash fell from the sky, Mr Ruete said. “It’s one of the elements where, as far as I know, we’re not quite clear about it,” he admitted.
He also noted that early results of the 40-odd test flights conducted over the weekend by European airlines, such as KLM and Air France, suggested that the risk was less than the computer models had indicated.
The acknowledgement that the computer models were flawed is likely to provide ammunition for critics who believe that authorities have shown excessive caution. The closure of much of the airspace over Europe over the past five days is estimated to have cost airlines a total of $200m a day in lost revenue.
Mr Ruete’s comments highlight the lack of technical expertise that has hamstrung European policymakers as they try to manage the consequences from a rare act of nature. Mr Ruete compared the scenario with his work in the 1980s trying to assess health risks after the Chernobyl nuclear accident.
He also urged European officials to consider adopting US aviation standards.
“If you take the situation across the Atlantic, there the advice would probably be: don’t fly over the volcano. Otherwise, it is up to you to take the precautions necessary,” Mr Ruete said.
While the US system leaves air carriers with the responsibility to determine whether or not it is safe to fly “the American model is not a model of less safety”, he said. “You just need to look at the statistics to see that.”
Under European rules, member states have the power to decide whether or not their airspace should be open. But decisions during the past week have been guided by computer models from the Volcanic Ash Centre in London and Eurocontrol, an organisation that co-ordinates air travel.
European safety procedures on volcanic ash were put in place after two incidents involving British Airways and KLM jets in the 1980s, in which aircraft engines lost power after flying through ash above Indonesia and Alaska.
In the wake of those events, the International Civil Aviation Organisation, a UN body that sets flight standards, asked air traffic controllers to develop contingency plans. Under these plans, the presence of ash prompted airspace to be restricted.
Mr Ruete said it would require more study, and backing from all 27 EU member states, to use a US-style system, which gives carriers greater latitude – and potential liability – to make such judgments.
Mr Ruete’s opinion was seconded by airlines, which have argued that the risks have been over-stated. “Our flights have shown that we can fly safely in these environments,” said Aage Duenhaupt, a Lufthansa spokesperson. “The mathematics and the reality in the air have no correlation,” he added, referring to computer models used by the Volcanic Ash Advisory Centre.
Additional reporting by Chris Kay in London