What is an acceptable accident rate? This link
Accident statistics indicates a one in five million risk per flight of a passenger on one of the best airlines being involved in a fatal accident, rising to one in 160,000 for one of the worst airlines. If the ash cloud were to continue for a year, how much extra risk would airline captains accept, if staying on the ground meant failure of their company? When I used to fly hang gliders I was content to accept a fatal accident rate of one per 10,000 flying hours - but I don't think I would want anywhere near that risk as a fare paying passenger.
