During the wet season helicopters landed and little dust was raised, during the dry season they produced a cloud of dirt. With no wind the cloud could stay around all day. The backwash of air from the blades was strong and turbulent. Larger more powerful helicopters such as a Chinook embedded sand in bare skin. They transported our supplies and carried some returning trash slung underneath. After being under a Chinook hooking a load, we spent our next free time picking sand out of our skin. Clean hair was impossible so I shaved my head for a few months.