Originally Posted by
OH58D
Dust is a problem for visibility and for an open cockpit like the MH6/AH6. The engine intake uses a baffle for the air intake which eliminates most of the fine particles. A more serious issue caused by dust is a static charge on the leading edge of the rotor blades, which you can see in low light. You touch the aircraft when it's not grounded and the static charge is enough to knock you flat. That's why sling load crews use an extended hollow tube grounding pole to dissipate the charge before connecting the load.
For the small aircraft like the Little Bird, if I were hovering in heavy dust at say 8 feet or so above ground level and someone grabbed the skid at arms length, it could be a shocking event. That's why the FRIES (Fast Rope Insertion Extraction System) runs the three inch thick rope out on each side away from the skids to allow an operator to hook on, but not actually touching an un-grounded part of the aircraft. The Fast Rope system can be quite effective for exfil operations and quick departures from a location. Most people see it only for fast roping in. There's a FRIES mulit-use rope for going in and out with hooks and lanyards, then there and a special rope with heavier clips strictly for exfil needs.