Something doesn’t seem right here. The Met Office maps covering from 1800 yesterday ‘til 1200 today show the predicted affected areas as big as, if not bigger than they have been previously. Especially over and around the UK.
What I don't understand is how The Authorities’ know that the ‘actual’ and 24 hour prediction maps are anywhere near accurate? We are told that the fine ash capable of causing engine damage is generally not visible even when flown into. I can see that sensors on Environmental Research planes could detect it but can’t get my head around how they can have so many covering the vast areas shown on the maps. There is also the question of upper and lower levels of the ash clouds. How can they ascertain these over the whole periphery and anywhere within these massive areas to determine if there are safe routes through them?
Perhaps Dave or others with ATC or meteorological experience can explain how the information is gathered and just how accurate it is considered to be.
From the pictures of the F18 engines, it seems obvious that no matter how many test flights BA, Lufthansa, KLM etc have flown which show no signs of damage, until the Met Office, NATS, Eurocontrol etc are certain that there is no ash in the atmosphere through which commercial flights could be flying, all airspace that could possibly be affected should remain closed.