Reply to the basic question...

Served a few years in Omaha (Hi, Bob!) in the 1970's. Flew a lot with the Orbiting Eagles.

We did a flying show for a church group or orphanage (it's been years, some details fade. Others do not.) The location was many miles south of Omaha, along the Missouri River. We could see clouds stacking up out at horizon distance further south - vicinity St Joseph, MO? Lovely thunderheads; very picturesque. Bright daylight, so couldn't see - or hear - if there was any cloud or ground-strike lightning. We started getting zapped whenever we went up: loop, wingover, anything much above low level flight.

Not particularly unusual, in that part of the midwest anyway. So we stayed low, if we flew, and used a handy trick to bleed off handle shocks: contact with one of the flying lines, or the metal adjuster on the back of an EZ-Just. Idea: conduct away the charge before it builds enough to jump a gap. If it jumps a gap, it has plenty to give you a sharp sting...

Got so bad that that didn't work well. No shocks at the handle, but the charge grew enough to jump through our sneaks into the ground (in both senses of the word 'ground!') Nasty! War dance until the tank runs out? Been there, done that, NO thanks! We packed up the flying stuff and just discussed the hobby and the equipment with the kids...

Another incident turned out worse. None of us regulars involved, but a site we often used was. Below Bellevue, Nebraska, just south of what is/was? Offutt AFB, and nearer to river level was a cleared flat space, a flood shoulder in case of high water. Most of the town was atop a bluff further from the channel...

Someone none of us knew was flying alone there and apparently got too close (for the atmospheric conditions, anyway) to some high voltage, cross-country lines. A notice in the newspaper mentioned severe burns to the guy. I went out and took a look at the site. Sure enough, there was a sort human fetal position char mark in the grass, at least 200' fom the nearest ground under bare hi-voltage wires...

Jim, was that you at a Lincoln(?) NATS who put a combat model's lines across power lines and - as you said - blacked out quite a bit of area. Don't answer if statute of limitation hasn't expired .

I DON'T trust arbitrary definitions of how far is safe! In one example above, 30 miles from thunder clouds was noticeably affected. In the other, in Bellveue, closest approach couldn't have been less than about 140', not including the slant up to the actual lines...