The pilots of these types of operations concern themselves with specific questions when performing external load operations. They want to know the type of load, the drag that it will create, the weight, the conditions for pick up and set down, how tall are the obstacles in the immediate area, what the distance is between pick up and set down and how many people are involved. Loads can come in all sizes and shapes. Logs, air conditioners, towers, vehicles, and more. They can even be live cargo.
Firefighters use water buckets hanging from helicopters to perform initial attack missions.
Whatever type of load you are hauling, rigging and weight of the loads are very critical. Some of us have felt that sick feeling when the load, for whatever reason, departs the aircraft unexpectedly. This could happen if the load was not rigged correctly. Remember the type of sling or clevis must be able to handle a far greater weight than the actual load. This is because the G forces on a load, increase its relative weight.