Ash/Silicon + Pressure/Temperature = making sort of glass in Engines = poor net performance risk = Gravity considerations.
.......At least, right or wrong, that's a simple way to regard it, and then read Notams and fancy new Met sites....
P.S.
'Brownstar' .....ref your post, a couple above. I was BA 747 fleet, and once, when sitting next to the captain during a routine classroom event, I asked him why they didn't merely avoid the area to start with. Trouble is, that I can't recall what he said. Must have been a reason, I'm sure.
Last edited by ONE GREEN AND HOPING; 24th May 2011 at 06:31.