Dusty B:
Fair enough to use mathematical models for forecasting weather patterns and cloud movements. This is quite scientific and has years of proven ground.....BUT to use theoretical mathematical formulas that have never been tested to predict the levels of concentration of the volcanic ash that is dangerous to aircraft would appear to me to be verging on irresponsability.
On the other hand, one has to say in their favour, that if they are not provided with electric screwdrivers, then they are doing a very good job using a hammer for the screws......