Air travel in Europe inched back to normal Wednesday, as officials
estimated that newly opened flight routes would permit air traffic to
approach 75 percent of its normal capacity. Ash plumes from Iceland's
Eyjafjallajökull volcano had all but extinguished flight operations
across the U.K. and mainland Europe for
the better part of a week.
Barring a tragic outcome, which is thought to be unlikely, it will be difficult to know the extent to which jet engines can tolerate mild to moderate intakes of ash. The damage might be cumulative and is tough to detect, says Michael Fabian, a professor of mechanical engineering at Embry-Riddle Aeronautical University in Prescott, Ariz.
In an effort to keep planes and passengers safe, officials broke the affected areas of airspace around Europe into three tiers: normal flight zones where ash no longer poses a risk, no-fly zones where ash remains in high concentrations, and intermediate, potentially hazardous zones where flights can proceed with caution, subject to route restrictions and other limitations. To draw those boundaries, flight controllers were forced to determine what constitutes an acceptable level of volcanic ash, despite a lack of data to inform their assessment.
To read the full, original article click on this link: How Much Volcanic Ash Is Too Much for a Jet Engine?: Scientific American
Author: John Matson