No I dont think its a 500 thing, just a helo thing.
When I was required to repel from helos both Huey's and Blackhawkes & get winched into them, we were always reminded to make sure that the shackle was stomped into the ground to discharge the static built up by the rotors.
If we didnt ground it enough, we would recieve one hell of a kick that removed any feeling of that hand/arm/shoulder for a few days.
Some times there would be more static or it built easier when the air was dry and dusty ( Australia you say ...no.. really? ) and that also made it harder to earth by stomping it into the ground.
Some times the Loady would yell/ hand signal at us to ensure we kicked the **** out of it so that we wouldnt get shocked.
Some times one of the boys was a little too impatient to kick it in good and would pay the price.
It happens when you have a lot going on and your on a warm excersise simulating that 2 way rifle range.
( it can happen when the ground is really dry and doesnt conduct so well ).
I have not been booted but can attest to friends not being able to hold their own rifle/kit and complain about their hand etc throbbing really bad and loadies
like a school boy.
No burns that I saw, just a lot of un happy chappies.
I made the mistake when in briefing of asking pilots what happens to us when we are being slung underneath and they have an engine failure ( 1 or both depending on how many it had ) and the answers were always " Don't worry mate, we will look after you".
See now being under the helo at 50 odd foot and us being more than 50 off the ground always made me think that we are going to get an early flying lesson as no one would ever tell me what their plan was.
I assumed we would be cut away and they would attempt an auto ( whilst being right in the middle of the HV curve) & hopefully the spinning separating parts are further from us.
Any one able to elaborate on this?
Cheers HF