Small is the only type capable of agility near the ground. They all need descent refusal at terminal stage if a computer understands they cannot pull up. Something like an auto leveled air cushion of five feet overriding controls. Pilots are cautious of unresponsive controls & momentum. They steer a little like a hovercraft.
A terrain aware auto pilot is already being used in some attack helicopters to keep them low. I want auto correction at steer & speed critical state in the heat of battle, also proximity to objects refusal within a few feet.
