The Chinook in dusty conditions builds a bit of Static.....well actually....enough to replicate Lightning almost.
In the infinite wisdom of the US Army, some innovative folks once put a static discharger on the side of the fuselage which was supposed to safely discharge static buildups.
There was a Pilot operated set of switches for operating the system and the default position on the ground was of course the "Off" position.
As Sod's Law prevails in the US Army (oh but doesn't it!).... along trods a young Soldier heading to his Bunker on the Flight Line to pull his Night Sentry Duty and like a Bolt from the Blue.....a huge arc of fire and brimstone flashed from the parked Chinook...to his Steel Helmet and then to ol' Mother Earth.
Wiser heads prevailed and the Static Discharging Systems were all removed from the Fleet.
A Golden Rule while hooking up sling loads.....always touch the lifting tackle to the Hook.....never hold the lifting tackle in one hand and touch the cargo hook with the other hand.....as it will sometimes be a thrill.