Originally Posted by
brooksjg
Key problem is the precision of the data!
OK - chances are that 2000 micrograms is low enough not to be a problem for that particular flight.
But what about the variation in ash density that the aircraft actually encounters? It might be lower or marginally higher than the magic 2000.
The magic 2000 itself has a safety margin over what the mfrs. provided as a figure. There is also a buffer zone around the predicted 2000 concentration zone as a further safety margin.
Also there's the question of cumulative exposures and what that does to projected remaining on-wing life.
That's the airlines problem. The shutdown cost to them has been quoted in excess of £200M per day. That's several new engines
per day. Reports of any damage, let alone written off engines, from several days flying through non-zero ash seem to be rather rare...
Personally, I do think that long term there will be some increase in maint costs and reduced engine life, but not significant. A few nutters with fizzy drink bottles, and the reaction thereto, have probably cost the industry more.