1. See and avoid doesn't work by day with fine ash clouds as has already been demonstrated. It certainly doesn't work at night.
Nope, Sunfish, at night "see and avoid" doesn't seem to work but, correct me if I'm wrong, until now there has never been an ash incident or damage while staying in daylight VMC.
This is about managing risk for a fleet of 1000+ aircraft engaged in European travel at any given time. As I said many pages ago, the penalty for getting the ash forecasts wrong is hundreds and hundreds of damaged aircraft sitting on the ground for months as they wait for their engines to be rebuilt by overloaded maintenance facilities staffed by exhausted engineers.
To put it another way, there are not hundreds of spare engines sitting around in Europe or America for some mass engine change.
To put it yet another way, suppose the forecasters get it wrong, or the volcano decides not to cooperate and Forty B747's need engines changes as a result. Are you going to sit there and argue that Boeing/GE/RR or the airlines should have had 160 spare engines just sitting around unallocated against this possibility? I can tell you they don't.
Oh come on, Sunfish, not again!
Remember my question from
post 2646:
"Sunfish, could you enlighten us please and give us ONE example of an aircraft that had extremely costly damage to the engine, after flying through an ash cloud so thin that it wasn't noticeable to the eye! Juste ONE example! PLEASE...!!!" Still awaiting an answer!!
Nothing catastrophic is going to happen if you fly through ash concentrations so low that it stays invisible to the eye.
Maybe -with emphasis on maybe- there could be an increase in maintenance cost and for extra engine checks, but these costs will surely be much less then grounding thousands of airliners without a very good reason.
And pardon me for saying so, but looking at your profile and the a/c you're type-rated on, you're not really in a position where you can call yourself an expert. I think you will be in more danger by
forgetting the carb heat on your Rotax, then you will be by volcanic ash in an airliner! Please don't forget what the "Pp" stands for in Pprune!
Ok, the above sentence is a cheap shot, and something I don't usually do, but the way you have been hanging on to your "oh boy, we're gone crash"-scenarios without valid arguments are getting very boring.
Best regards,
Sabenaboy