Alaska Airlines' 30 years of experience in dealing with volcanic ash could serve as a model for governments and airlines worldwide, writes Wall Street Journal columnist Scott McCartney. With an "unbendable rule" against flying in ash, the airline goes to great lengths to determine exactly where it can safely fly following an eruption. Off-duty pilots are scrambled to fly private aircraft and empty passenger jets, gathering atmospheric data that are paired with computer models and satellite projections. Armed with such information, the airline operates flights as long as it can stay 35 miles clear of an ash cloud. "The more data you have, the more surgical you can be," says fleet captain Ken Williams.