Met experts accused of causing chaos for passengers
Published 20/04/2010 | 05:00
AN eight-man team of experts at Britain's Meteorological Office was accused yesterday of causing an unnecessary shutdown of aviation with poor-quality computer modelling and "limited" scientific data.
The European Commission accused the unit, a previously obscure part of the Met Office based in Exeter, of starting a chain of events that left the travel plans of more than a million passengers in chaos and the airline industry with potential losses of more than £1bn.
The scientists make up the Volcanic Ash Advisory Centre (VAAC) for north-west Europe, an area that includes Iceland and Britain. Its computer model predicting the travel path of ash from the Eyjafyollajokull volcano was cited by European air traffic control agencies as the trigger for the unprecedented shutdown of aviation over the past few days.
That model was under scrutiny on Monday night as the blame game began over whether the shutdown had been an over-reaction to the threat posed by the volcanic ash. Britain's air traffic control service, the government, the United Nations and even jet engine manufacturers were all drawn into the row.
The computer model used by the weathermen in Exeter was devised by the Met Office in the aftermath of the explosion at the Chernobyl nuclear plant in the former Soviet Union in 1986. It calculates the direction, speed, height and density of any particles that travel in the air -- be they from an industrial accident or a volcano.
It is called the Name Dispersion model, or to give it its full name, the Numerical Atmospheric Modelling Environment, and is used by all 10 VAACs around the world.
However, it is reliant on good quality data and is usually reinforced by information from test flights, which use sophisticated equipment to determine what is happening in the atmosphere.
It emerged Monday that the VAAC had triggered last week's alert without sending up a single test aircraft to supplement its computer predictions. All the data had been collected from ground radars called Lidars.
Captain Jo Gillespie, a member of the International Advisory Committee on Flight Safety, said data gathering should have begun as soon as the eruption began. "Military and research aircraft should have been sent straight up to determine the nature of this ash cloud," he said. "The density and the make-up of the cloud is what matters and that information just has not been available."
Matthias Ruete, the European Commission's director general of transport, said the model was running on mathematical projections rather than what was actually happening.
"The science is based on certain assumptions where we do not have clear scientific evidence. We don't even know what density the cloud should be in order to affect jet engines," he said.
Britain's major airlines also questioned the science behind the projections, writing a letter to Lord Adonis, the Transport Secretary, saying that "key decisions" had been taken on the basis of "very limited empirical data".
Only four test flights have been conducted since the chaos began last Thursday.
Despite this, NATS, Britain's national air traffic control service, which is in charge of British airspace, and the Civil Aviation Authority have relied on the VAAC's model to guide its decisions.
They started grounding flights 12 hours after receiving the alert, with Scottish airports the first to shut early last Thursday.
These two bodies cited regulations from the International Civil Aviation Organisation, part of the United Nations, as the basis for their reaction.
These regulations bind air traffic controllers around the world and stipulate that it is the duty of controllers to ensure that aircraft are never directed into a hazard.
These specifically include a thunderstorm or a volcanic dust cloud. (©The Daily Telegraph)