The computer models used to determine whether it was safe for airlines to fly through the ash resulting from the eruption of the Eyjafjallajökull volcano in southern Iceland were flawed, European Union officials now admit, says a story in the Financial Times of London.
The FT says that the models used were "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."
The FT story also says that the models lacked basic information, such as "what concentration of ash was hazardous for jet engines, or at what rate ash fell from the sky."
Airlines have been complaining for days that airspace over the UK and Europe was unnecessarily being closed. The airlines, the FT says, have conducted some 40 test flights through the closed air space and their results were much less severe than the models predicted.
However, according to this story at The Register, the decision to ban flights was made on the "basis of one computer model, which [the UK Met Office] didn't check against reality." In addition, the Register story says that the Met Office used data from only four test flights to feed into its computer model.
While the blanket ban of flying into the UK and Europe was lifted last night at 10 PM after six days, it will take days before normal flight schedules are resumed. Over 500,000 passengers have been stranded by the ban, and airlines have said they have lost some $2 billion in revenue.
Calls for an investigation into how the flight ban was decided and whether the risk was exaggerated are already being heard. This story in today's London Daily Telegraph says that volcano experts, however, are backing the decision to ban the flights, which guarantees the controversy over the decision to close off air space will not go away soon.
It will be interesting to see what decisions will be made if the Eyjafjallajökull volcano once again spews out a large concentration of ash.