To add a lighter note to the thread, here's a funny situation I was involved with back in the 80's... it does, loosly, involve rappelling. Or rather, not rappelling...

History: The vast majority of SAR activity circa 1980 in the NH White Mountains was based around volunteers from local outdoor clubs like the AMC. You had to figure that YOU might have trouble some day, so when someone else did, everyone pitched in and went searching. I was up in the Presidential Range, trying to get a couple down that had gotten rather lost above tree line. It was the only time I recall actually being in the first group that "found" misplaced hikers, having gone on such search parties many times. There weren't cell phones back then, or GPS, sat phones, etc, so you just basically knew someone was missing, and hopefully where they started and where they were heading. Maybe if you were lucky, you knew the last hut they stayed at, or which trailhead their car was parked at. Groups would head out along all the likely trails, hoping to find the missing folks.

Ok, so we have this husband and wife, and we are in near white-out conditions. As most of you on this forum know, above tree line, you navigate from cairn to cairn, essentially piles of stones. Without snow, they are easy to differentiate from the surroundings, with drifting and blowing snow, not so much. We weren't roped up, not technical climbing, nothing like that. Visibility was low enough, however, that we decided to send our point guy on a line to the next cairn, which sometimes took a while to find, then follow that.

Well, the poor woman who we were rescuing sees one of our guys clipping a thin line, probably paracord, to their jacket, and walking off into the distance out of sight. She started screaming "oh my God, oh my God, I can't do that!!!". She thought that were were going to start lowering people off the mountain on a single strand of 550 line:-) Fortunately, her husband was the first person to start laughing hysterically, which made it ok for the rest of us to do the same! She didn't really see the levity of the situation for a while, but, eventually laughed about it at the Joe Dodge Lodge at the base of Pinkham Notch. I'm laughing about it again as I type this:-)