CaptainPaddy
Nothing in aviation happens fast if we had waited "normal" periods for complete analysis and normal regulations by the time they were out there would be no Airlines left in the UK who were still solvent to apply the new regulations to.
Pace
Firstly not true. From today onwards, the general wind direction was always forecast to change the situation dramataically. Even for this reason alone I can not understand the rush. We have squeezed out new regulations in record time to give us 2 days extra flying.
Secondly, I'm actually at a loss that so many people seem to agree with the philosophy of rushed regulations. What you are saying is it is better to get flying now, disregarding the lessons of the past, without knowing what the consequences will be in order to keep business operating, instead of doing what we all claim is our first priority - move people and cargo around safely. How can it be safe if it is unknown. That has always been the mantra we supposedly hold oursleves to.
Thirdly, this is not some abstract threat. The Natural Environment Research Council have had D228's and 146's in the air above the UK since Tuesday. They say "Results from both flights revealed the presence of sulphur dioxide and a number of layers of volcanic ash of varying sizes between ground level and 20,000 feet. These discreet layers of fine material are particularly difficult to spot with the naked eye." In other words you could see them if you knew where to look and what you were looking at. We are not talking about invisible, extremely diffuse ash concentrations here. Yet we are flying around like there's no risk.
Fourthly, I agree the RAF may have flown around at low level for longer periods, but the point is that damage was sustained. That means damage is possible. If it was only because they were at low level for 2 hours or whatever, should we then limit holding at LHR to 30 minutes before you hvae to climb above FL200 again to mitigate the risk? You're talking yoursleves into this. If it is only a low level risk, what level is too low and for how long? None of those questions have been answered. At the end of the day if you sustain visisble damage after a particular period of time, you can not say less time means no damage. There is a cumulative longer term effect that must be taken into account.
Lastly, all authorities are going on the basis that the ash concentration is effectively minute and uniform. The NERC flights have proven that to not be the case. Yet they have carried on regardless.