This one happened so long ago that I have a hard time remembering the pucker factor, although I am sure it must have been substantial.
In the early 70' I was working as a bush pilot in the Canadian Rockies. On the day in question, I was flying a Hughes 500 in and out of a tiny pad constructed as customary of logs and grafted onto the side of a very steep mountain with about 10 feet to spare between the rock wall and the MR blades.
Having dropped whatever load I was carrying I lifted and started backing away from the wall far enough to turn around and fly away. About half way through the pedal turn, there was a very nasty noise coupled with a very rapid and severe loss of power.
We had already cleared the pad enough not to hit anything and I was able to start diving to hold onto rotor RPM. Lucky for my passenger and me was that we were coming of the side of a very steep mountain at about 6,000 feet AVL (V=valley) and therefore had "all the time in the world" to get things stabilized on the way down and to pick a suitable landing spot.
In the process, I determined that I still had about 20-25% torque available and wasn't over temping. This turned the landing into a relative non-event.
Later investigation brought to light that the compressor had thrown a blade which had promptly been vaporized in the fire pot. Somehow, the engine didn't flame out and I get to tell the story to the young'ns once in a while.
Cheers
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