Helicopter Static Electricity Question? NLC

[s29ttc]

Me and my mate in work where just talking away there and got onto the subject of the static electricity produced by helicopters and can't seem to work out why when they lower a rescuer they don't suffer a shock from static when he/she gets lowered to the ground? Anyone with any knowledge (Tut springs to mind) clear this curiousity up

[Peter]

STATIC ELECTRICITY CAN BUILD UP IN ANY HOVERING HELICOPTER. A STATIC DISCHARGE WIRE IS ATTACHED TO THE END OF THE WINCH CABLE. DECK CREW SHOULD ENSURE THAT THE STATIC ELECTRICITY DISCHARGES THROUGH THE DISCHARGE WIRE.

Stolen from a marine advisory note...

[s29ttc]

See we thought this would be the case but when we were thinking about the stuff you see on films/documenty etc its something you don't remember seeing or checking. It look as though they just winch down and grab the person quickly

Thanks for clearly that up, just got really curious thinking about it

[Peter]

Doesn't sound too serious, it looks like most ships etc have this in there safety notes but the reason seems to suggest that it could compound the effect on a person who is already badly injured.

I'd offer to jump out next time I'm up but that would have some dire consequences in an R22

Still don't understand how this works for people climbing onto the skid of a hovering helicopter though?

[DJ]

Static does build up and is discharged through the person touching the ground. In my days of active monutain rescue, we were warned about it before abseiling out of the RAF Wessex and RN Sea Kings. One guy, for some bizarre reason, always used to touch the ground bum first rather than feet as said it was less of a shock.

[tut]

As said above, static electricity can give a quite severe electrical shock, especially when picking up underslung loads, so an earthing rod is used by one of the ground team before anybody hooks on.

Also on re-fuelling the helicopter has an earthing socket on the side and a wire is plugged into this. If it is a wheeled helicopter the tyres are made from electric conducting rubber.

tut

[paul555sti]

Slightly off topic but i thought you guys would enjoy this video.

http://www.youtube.com/watch?v=EQYDToVK6Z0

[Peter]

Mental, I saw something similar on Channel 5. They even pressure washed the live lines from the helicopter..

[Skyenet]

As said above, static electricity can give a quite severe electrical shock, especially when picking up underslung loads, so an earthing rod is used by one of the ground team before anybody hooks on.

Yip I have used one of these rods many a time, we called them "sky hooks"

When getting winched into aircraft I would let the hook touch the ground or water first before attaching it to my winch strop.



The Seaking was one of the worst for getting static shocks off

[tut]

You look like Buster Crabb there Iain............



tut