Why don’t helicopters fly higher then any obstacles so this does not happen?
Kobi Bryant helicopter flew below the hill tops in the fog when it was blue skies above the hilltops. They crashed.
I read that if they had climbed, because of airspace restrictions in that area above them, they would have had to declare an emergency. They were under visual rules at the time.
But no pilot wants to do that - it jeopardizes your license and injures your pride. The pilot may not have even considered climbing - or instead took what could be characterized as a calculated risk, and lost.