Flying in areas with ash clouds near should probably be treated like icing conditions earlier in aviation. Ice could kill you if you didn't respect it but it could be dealt with if you handled it properly. Little is known about how much ash is too much now. We need to study it and learn from this incident how to deal with it better. We have so much technology now to study it, Drones with monitors would give us a wealth of data. This will happen again, over and over, so we need to know how to deal with it. What would happen to aviation if no one could fly within 100 miles of a thunderstorm?