Quote:
Now, scientists and engineers have agreed a threshold concentration for ash of 0.002g per cubic metre of air. At or below this concentration, there is no damage to the engine.
But this is a TV news report. How are measures taken?
What time scaling: 15 min? hourly? 8 or 24 hours? ...like terrestrial air pollution?
Where are the specs?
"Considering that a commercial aircraft will travel about 150 km (80 M) in 10 minutes and that volcanic ash can rise to flight levels commonly used by turbine-engine aeroplanes in half that time, timely response to reports of volcanic ash is essential."
from ICAO EUR/NAT OFFICE (Paris): Volcanic Ash Contingency Plan EUR Region (Second Edition September 2009) Page 3