rather higher indeed than Pace's estimate of zero risk.
PBL
Where please have I indicated that there is Zero risk?
When you get up in the morning and cross the street there is not Zero risk that you will not be flattened by an out of control Lorry!
There are in my book two types of risk. Demonstrated risk where there is previous evidence of that risk causing real harm to life and if you like suspected risk where there is no evidence of a threat.
We all know that aircraft crash in strong winds and shear and do so on a continuing basis. We have wind limits as well as cross wind limits to work within but still the crashes happen.
What do you do? do you drop the acceptable wind strengths and make travel by aircraft less reliable. Do you train pilots better or give them better equiptment? But that is a demonstrated risk which is known and which we appear accept.
We know that flying into dense ash can stop engines that is a demonstrated risk with a couple of incidents to prove.
But light ash has a suspected risk only! does it warrant the massive cost and destruction to the aircraft industry that we have bestowed on it mainly demanded by media hype and scaremongering?
If you have evidence that light ash can stop engines in flight show it?
No one doubts dense ash. That can be seen and mapped but light ash cannot. For that reason we have computer generated mathematical forecasts of where it may or may not be.
But frankly until there is some evidence I personally have no fear of flying in clear air which may hold the equivalent of half a thimble full of talc in a five bedroom house to me thats paranoia.
Unless of course you practically prove otherwise and not by another load of mathematical calculations.
I totally support more inspections on aircraft flying in light ash as my only concern as a pilot is damage that can bring an aircraft down (and not increased maintenance cost) but to close huge blocks of airspace on an as yet ungrounded fear is overkill (excuse the pun)
Pace