When flying at night ash clouds are not visible to pilots, in addition they do not show up on radar, the small size of the ash particles do not return an echo to the onboard weather radars of commercial airliners.
When flying at night ash clouds are not visible to pilots, the small size of the ash particles do not return an echo to the onboard weather radars of commercial airliners. This is in addition. They do not show up on radar addition.