Many years ago I was conducting flood relief with the mighty Wokka when I was called in by the brigadier in charge of the operation and told that I would have to stop flying because the danger to life was over and that from now on it would cost £20000 per hour for the flying time. I had just refuelled and told him that we would continue until we reached minimas and that I would put the hours down to crew training (which was excellent value for us by the way). They got well over another 100 tons of sandbags in place as a result and definitely stopped about 500 homes being inundated.