There's a bit of a difference between a request for a height / heading change (at least partly) for the comfort of pax and a 'must have' change because the current heading / height is not going to be 'safe' after another n minutes (where n is less than 5).
BrookSJG
Yes there is a hell of a difference between flying into a CB which does have a record of killing you and Ash which doesnt.
The must have are active CBs and I have never heard of ATC forcing a pilot into a CB against his wishes. Deviations are ALWAYS given even over busy London.
The London controllers really earn their Keep on such days a few ash deviations really wouldnt be a problem! Kids play in comparison
really where do some of you people get your assumptions because they dont match reality?
For these reasons, I cannot see how the proposed passive IR system could provide consistent or accurate data about VA actually flown through.
We have the same old problem from the Ash thread of differentiating between dense ash and light Ash. The dense ash will show up from satellite screening, on board sensing as well as the MK1 Eyeball. The light stuff wont show to anyone with accuracy and thats the problem! Thank God to date the light stuff doesnt appear to be a problem.
Pace