Question: Can radars detect dense ash ?

that’s a really good question!

I *think* that radars can detect ash, but only if the amount of ash in the sky is enough to be picked up by their equipment. This is the problem, the amount of ash that you need to break and aeroplane engine is much smaller than the amount that can be recorded by a radar, so you might have an aeroplane flying into an ash cloud without realising!

I think some aeroplane companies are now working with scientists to develop much better radars which can see smaller ash clouds.