DHC8 Autofeather
Having previously worked many years on the Dash 8s, I was equally interested in this post, as it didn't ring any bells either. Just read through my training notes, and sure enough, there it is. In an autofeather situation, and also an overtorque situation, Power Uptrim light on, and non affected engine uptrims 10%, non affected engine bleed air shuts off ( I assume to allow max power availability).
After 3 sec delay, unaffected engine autofeather inhibited, and ARM light goes off. Back-up uptrim signal to unaffected engine, affected engine prop feathered. Deselecting the autofeather switch will turn the unaffected engine bleed back on again. That is a very basic description, as there are several other bits and pieces going on at the same time.
It must have been an afternoon session when we went over that part, and I was nodding off! Still, it proves that you never stop learning in this business!