[Tzfat]

Dust that can cripple an engine can be so fine you cannot see it I would NOT want to fly though it- it is already shown that it can destry an engine

Do you have proof of that statement?

Boeing and Airbus provide clear guidance - no pitting on windshield, fan blades, leading edges - no damage to the engine. This is what happens when know-nothing academics talk to politicians... and never ask the people who manage risk for a living (pilots, aircraft manufacturers, airline operations).

[cripplecreek]

The problem is that the ash wasn’t where computer models said it was. Any pilot who says it won’t damage a jet is an idiot who needs to be grounded. Boeing and Airbus flew test flights through clear air because that was where computer models wrongly predicted the ash would be.

http://www.skybrary.aero/bookshelf/books/1161.pdf

British airways flight 9. Engine failure caused by ash from Mount Galunggung.

On 15 December 1989, KLM Flight 867. Engine failure caused by ash from Mount Redoubt.

[UCANSEE2]

Finnish F-18 engine check reveals effects of volcanic dust

http://www.flightglobal.com/articles/2010/04/16/340727/pictures-finnish-f-18-engine-check-reveals-effects-of-volcanic.html