Can a AAD survive powerlines?

[toronto_bill 0]

I was just mulling over whether you can expect a AAD to be a 'melted hunk o junk' after a landing in powerlines?

I guess if it aint grounded then its okay? But, I imagine you want it to be checked. Would a FXC have a higher survivability with no electronics?

No one has ever landed in anything but trees round here. We are currently waiting for a runway to dry. So I admit I am bored.

Bill

[havensiangst 0]

the more important question here is...would you survived these powerlines?

[ZigZagMarquis 9]

... maybe we just found yet another use for an expired Cypress!!?




But seriously... Don't Try This At Home, Kids!

[toronto_bill 0]

As you can tell I'm not exactly a 'grounded' person. Hehe.

[tdog 0]

Well, from my electronics background, the answer is "it depends".

If you land in power lines and don't touch the ground or another power line, you have "potential voltage" but "no current." You live and never get a shock and no current will go thru the AAD.

You touch two power lines or the line and the ground, the current will flow, and you most likely will die, or at least lose the body parts that touched the line.

Now... what about smaller power lines that shock good, but have a small chance of killing - like the lines from the transformer on the pole behind someone's house and the house. These lines carry 220 volts, and are attached in a way that most likely they would be broken by the impact of a large mammal - thus breaking the circuit seconds after impact, and thus causing a good shock, but not much more than when you were a kid and put your finger in the light socket. Yes, you very easily could die, but not a sure thing...

Well, here again, the AAD will be in the rig and insulated. No current will flow thru it. No damage.

I think the only time you would have to worry is if your car or home was struck by lightning - and the high voltage found your rig as the easy route to dissipate the energy.

[strop45 0]

Quote

Now... what about smaller power lines that shock good, but have a small chance of killing - like the lines from the transformer on the pole behind someone's house and the house. These lines carry 220 volts, and are attached in a way that most likely they would be broken by the impact of a large mammal - thus breaking the circuit seconds after impact, and thus causing a good shock, but not much more than when you were a kid and put your finger in the light socket. Yes, you very easily could die, but not a sure thing...

Greetings - the rest of your post is pretty much right on the money, but this paragraph is wrong... The low voltage lines in your street typically carry 110-240 volts and generally only have fuses for protection - this means that anything hung up in them has to carry enough current for long enough to blow the fuse. the high voltage lines 6600, 11000, 22000 volts etc have earth fault protection which will operate for small animals etc, but usually requires 1-5 seconds of fault and will turn said animal in a burning mess of carbon.

The human body (young and fit) can survive 50mA of current for 50ms. 110 volts is more than capable of supplying this and hence touching the live supply especially if you are earthed (touching something metal e.g. tap) at the same time is not a good idea and has killed many many people.

The hazard from powerlines to skydivers is twofold. Firstly if you fly into them at speed you will probably hit the ground at a faster speed. They are hard to see and even a minor hit could cause a loss of control. Secondly if you get caught in them you can get a shock by touching one wire and another wire. You can also get a shock by touching one wire and the ground, or a grounded object such as a roof or concrete/metal power pole/python. Depending on the voltage and capacity of the lines, burning is as dangerous as shock and if you push the wires together on a high voltage line you can release energy similar to the amount it requires to make a plane take off. See Lutz video for actual demo.

Back to the OP, it is hard to see any damage to the AAD in any circumstances where it would be of concern to the skydiver jumping it, put another way, if you are dead, badly broken or burnt, the function of your AAD will be low on your list of priorities.

Stay safe people.

The difference between stupidity and genius is that genius has its limits." -- Albert Einstein

[tdog 0]

You are right, the fuse is not going to protect a human.

However I was making a comment more on the strength of the wire and attachments.

I had power lines behind my old house that were taken out more than once by trees, trucks, etc.

Got good with dealing with them.

When anything of force hit the lines, they would snap or come undone.

Plus, they were insulated.

Not to say playing with any power lines is good. :-) I guess I should have clarified my thoughts.