Ash cloud concerns 'legitimate' say scientists

Europe's University of Copenhagen and the University of Iceland announced findings from an investigation into the Apr-2010 volcanic ash cloud that caused travel delays and cancellations across Europe (The Guardian, 25-Apr-2011). Susan Stipp, leader of the nanogeoscience research group at the University of Copenhagen, said that particles collected from the ash cloud were found to be sufficiently sharp to damage jet engines, with the universities supporting aviation authorities' decision to ground thousands of flights until the danger had passed. The ash cloud contained particles that were firm and sharp enough to put aircraft at risk from abrasion on windows and airframes and possibly melt inside jet engines and clog up cooling ducts. The closure of European airspace, which led to widespread criticism from European carriers, cost airlines and tour operators between EUR1.5-2.5 billion, according to statistics from the European Union.