Here is some (more then you probably want to know) information on hoist operations. Yes they can develop a static charge and occasionally do so. Low humidity generally will contribute to the build up of static electricity. I have been on 1 training operation in which my partner grabbed the basket prior to letting it ground and received a mild jolt.

Our team uses trail/tag lines to guide the basket down, the line itself is not a conductor, but the basket (attached to the metal cable) can hold and subsequently discharge. Whenever possible, we never touch the basket until it has made contact with the ground.

For the Maryland State Police (MSP), we use a Billy Pue net in the horizontal position for patients who are on a backboard or vacuum splint. We do not hoist patients in Stokes Litter Baskets with MSP (the one exception was the Raven Rock Rescue). For patients with minimal or no injuries, we use a standard Coast Guard Basket, generally with no trail/tag lines unless the wind is really up. The MSP trail/tag lines are weighted with lead/steel shot bag, which is lowered to us, allowing us to direct the deployment of the basket. Since most of time, we have very small area of operations either due to tree cover or are limited to the rocks on which we are working, directing the basket/net to us is critical. We then use the trail/tag lines to control the hoist, in the case of TRP 3, the Billy Pue net can not fit through the door of the aircraft, so the Medic will drop us the trail/tag line and attach a safety strap to the net and fly with the patient on the outside of the aircraft to an LZ, where they will transfer the patient to another MSP helicopter or ground unit.

For United States Park Police (USPP), we prefer to use a Stainless Steel Stokes Basket (does not catch the prop wash as much as a plastic Stokes Basket) with attached tag lines for all hoists. USPP will drop us their litter rig, which we will allow to ground. We then attach the rig to our basket with two trail/tag lines for the hoist. The Medic, once the basket is in the doorway will drop or cut the trail/tag lines free.

In the case of Katrina, I suspect the humidity levels were high enough, thus preventing the development of static electricity. If the situation should arise where you require hoisting, I would allow the basket to hit the ground before touching.

Pete