My two were offshore in the GOM, both in a 206. Nuts and bolts come undone under driveshaft covers that don't get removed on preflight. First was just after landing, thank the good Lord. (It was December and the wind was blowing 30 knots.)
Second was just after lifting off to a hover in a 206B. Sitting there, getting ready to go, I hear a BANG! and the world starts spinning sideways. I don't remember consciously thinking, "Tail rotor failure," but you know what it is, believe me. What surprised me was the rate of spin and how quickly it went from nice-stable-hover to spinning uncontrollably. I was thrown toward the center, hanging on for dear life while I collected what few wits I had (half the normal human allotment). With each spin it was translating a little downwind. Mind you, I was on an offshore oil platform with not a lot of room to drift downwind before being out over 100' of nothingness.
I rolled the throttle off, and like TET was dismayed to see the dang thing keep spinning. So instead of holding it off further I put the pitch down a little. The skids touched, we yawed about another 90 degrees, then came to a stop with the toes of the skids over the edge of the deck and me looking down at the water through the chin bubble.
Later, back at HQ for Recurrent, an instructor brought my "event" up during ground school. I did my best, "there I was" and complained about how it did not stop spinning when I rolled it to idle. And he goes, "Idle? Why didn't you go all the way to cut-off?" He did not add the word, "dumbass" but he could have.
And I slapped my forehead and went, "DOH!"
Ah well, sometimes we're Yeager, sometimes we're Homer. Next time, next time.
It sure does spin fast when you lose t/r drive in a hover though! What we simulate in training doesn't come close to the violence of the snap-yaw.