Pace, I think most if not all pilots here know the engines are not going to just stop when flying through even a red sector of ash. There is a big difference between that and the ash cloud BAW009 flew through. My concern though is that by flying through a low density area of ash I am causing a small amount of damage to the turbine sections, bearings, small amounts of glass stuck to the blades etc After the days work, then what ?........I hand it over to a colleague to do the next shift. Can a quick inspection by an engineer detect these small amounts of damage without the time for a bore-scope ? I doubt it. I know where your coming from Pace but it's the hidden danger that concerns me.
not only that but I SUSPECT that it is the case that with volcanic ash that there will be a concentration at which it's still safe to fly but not economic. In that situation it seems right, to me, that airlines can choose not to fly even though to fly would be safe. Planes aren't cheap and to chose to expose some to conditions known to cause damage (which may or may not be at a higher concentration than the current red zone) may be an expensive decision. On the 'test flights' I'd feel they were intended more for science than
PR if they had instruments measuring the (small) levels of ash they were flying through. The ash isn't going to be uniform through the red zone (or any other) and ISTM that what is needed is an accurate measure of the concentration flown through and the subsequent damage (or lack of thereof). I'd have thought only by calibrating the conditions flown through with the effect on the plane can sensible limits be set. Knowing only one (and
AFAIK the 'test flight' are only measuring the latter) doesn't seem very useful IMVHO