Interesting thread, particularly the autofeather/autocoarsen subthread. I have a personal story here.
A flight test aircraft was rigged with a "Kill switch" to stop fuel flow to the critical engine, independent of normal cockpit controls. A V1 cut was accomplished, with normal SE climbout in autocoarsen. After the desired performance point was demonstrated, a restart was attempted; but as the throttle was advanced above idle "all hell broke loose" with much shuddering and shaking. The engine was again shut down, and a SE landing was completed. This was unusual to me as a ground observer, so I met the aircraft on the ramp.
The chief test pilot cornered me and, very agitated, asked what the hell was happening. It was two or three minutes before I could get a word in edgewise.
Finally I was able to ask one question: "Was autocoarsen still armed?"
Instantly the heat was off. He knew exactly what had happened, and their flight test card was rewritten to include that vital disable step.
