I also agree wholeheartedly with Pace in praising the Met Office's efforts. It's not the forecasting or data that I have a problem with; it's the use the data is put to and the fact that no one seems to have thought to figure out the result of making new rules until confronted with the practical consequences...
we're dealing with mother nature here, ala rain, hail, birds and now ash
The rules are not made up by throwing darts at a board to guess what is enough.
They are a balance between reasonable avoidance and a practical degree of capability in the product.
Let's start with what can be reasonably avoided versus what one in 10-100 million hours of operation will encouter.
Can somebody as a volcanologist, meteroloigist, flight dispatcher, big iron pilot tell what level of ash they expect to encounter over the lifetime of the fleet ??? e.g. no more than 1 in 10-100 million hours of operation ??
Then we can ask the new engine guys developing engines available sometime 10 years from now if any of those engine can withstand that specific level of ash.
Don't be surprised if the answer comes out yes but at a 10% decrease in fuel efficiency down to B727, DC-9 levels.
OK back to the meeting rooms, now how much ash are you willing to avoid to still meet the product advancements in fuel burn forecasted for 10 years from now ?
You see the answer does not rest alone with the regulator, nor the manufacturer. In fact without stastitically viable data (not tombstone) engineers have no where to start.
BTW, today's products are pretty much frozen regarding upgrade capability to tolerate ash, so you still have another 20 years of what you experienced in the last month in Europe to contend with even if you pour development and rule making resources into the pot in the meantime.
Those are the practical consequences.
