Hover Holes....places in the triple canopy jungle where one cannot hover vertically but must maneuver around limbs, tree snags, and stumps. Leafy green tree limbs cut nicely but bamboo ruins the blade. The downward airflow from the rotor system sometimes "pulled" the tree limbs down to cause a decrease in size of the open area.
Using "hover holes" required the full crew....gunners to call directions to the pilots....one really learned to trust the crew in back and allow them to "direct" the aircraft away from the obstacles. I can recall more than a few occasions where it took a couple of tries to get out without hitting tree limbs that would have caused real problems. Just think of a "rat's maze" and that is what it was like sometimes.
Yes....chopping your way in and/or out happened during Vietnam Operations...but usually only in true emergencies such as evacuating critically wounded soldiers or rescuing down air crew.
The Huey blade is pretty durable....as is the Chinook blade.