The volcanic ash that led to a six-day shutdown of airports a year ago posed a serious danger to aircraft, according to a study by scientists.
Specialists in nanogeoscience – the study of small particles – at universities in Denmark and Iceland have found that grains in the ash cloud were sharp enough to put aircraft at risk of engine failure.
The wholesale closure of airports in the UK and much of Continental Europe last April caused chaos for travellers and led to fierce criticism of aviation regulators including the UK’s Civil Aviation Authority (CAA).
Willie Walsh, then head of British Airways, led industry efforts to get airlines back in the air by joining a test flight during the shutdown of airspace and then ordering a number of BA long-haul aircraft to begin return flights to Europe before the ban had been fully lifted.
It appeared that authorities had overstated the potential risks of volcanic ash due to a paucity of relevant data and studies into the impact on aircraft engines.
The crisis drew to a close as governments and regulators agreed less onerous restrictions on flying through low concentrations of volcanic ash. However, the latest study suggests the ash from the Eyjafjallajökull volcano in Iceland contained fine particles that were hard and sharp enough not only to cause abrasion on aircraft but to clog cooling ducts in jet engines.
Tests on particles collected from the ash cloud found the grains were sufficiently sharp to damage aircraft two weeks after the eruption.
According to Susan Stipp of the University of Copenhagen, who is quoted in The Guardian newspaper: “The air-traffic authorities’ decision to close airspace was absolutely the correct one.”
The study is reported in the journal, Proceedings of the National Academy of Sciences. Its authors conclude: “The very sharp, hard particles put aircraft at risk from abrasion on windows and body and from melting in jet engines . . . Concerns for air transport were well grounded.”