Eli5: why is volcanic ash dangerous to aircraft, and yet they can fly through forest fire smoke?

Question

Thank you!

In: 32

Answer 1

It’s like sitting next to a camp fire and smelling the woodsmoke vs grabbing a handful of ash out of the embers and snorting it.

Edit because my comment got mod removed…

The smoke causes no damage to an engine whereas the intake of larger particles can cause friction and abrasion. The sheer volume of this that they pass through over a volcano means an engine could be ingesting several kilos per second which will cause immediate catastrophic failure. This is not good.