Airports were closed even when there was no ash
ANCHORAGE International is Alaska's busiest airport and Mount Redoubt, one of the State's 41 volcanoes, is a little more than 100 miles away upwind.
When it erupted in March 2009, throwing vast clouds into the atmosphere, three millimetres of ash fell on the airport.Yet in the 14 days when Redoubt's eruption was at its peak, Anchorage still functioned.
Most flights came and went, although 60 aircraft had to take detours around the ash cloud, 10 turned back and 20 landed elsewhere. The airport closed for one day. Nobody crashed.