AVIATION AUTHORITIES were right to ground commercial jets for seven days after last year’s volcanic eruption in Iceland, a study has found.
Safety fears led to the action as fine-grained ash from the Eyjafjallajökull volcano blew into the path of aircraft over the UK and continental Europe.
The decision disrupted travel for 10 million passengers and cost €1.3-€2.2 billion, leading some critics to question whether it was justified.
A new scientific report published in the journal Proceedings of the National Academy of Sciences concludes that it was. Researchers analysed samples of ash from the volcano and found they were capable of causing an air disaster.
The fragments remained “sharp and abrasive” even after attempts to blunt the particles by stirring them in water. They would have sandblasted aircraft windows, making them impossible to see through, and had the potential to stall engines.
Fears over volcanic ash arose from a previous incident in 1982 when a British Airways 747 flew through debris from the eruption of Mount Galunggung in Indonesia. The pilot reported sparks from the windows and wings, and all four engines failed when melted ash coated their interior.
However, it proved possible to restart three engines as they cooled during the descent. The pilot landed while peering through a two-inch strip on a side window that had avoided sandblasting.
Laboratory tests carried out on the Icelandic ash suggested that a similar event could have happened again.
The researchers, led by Dr Sigurdur Gislason from the University of Iceland, wrote: “The very sharp, hard particles put aircraft at risk from abrasion on windows and body and from melting in jet engines.
“In the lab, ash particles did not become less sharp during two weeks of stirring in water, so airborne particles would remain sharp even after days of interaction with each other and water in clouds.
“Thus, concerns for air transport were well-grounded.” – (PA)