What do you call it if your Ng slowly falls down to 42% with the power level at flight idle in a descent? This happened to me the other day. The worst part was the engine wouldn't respond the power lever inputs after that. I was about to just shut it down, but then I figured I could accelerate up to Vne and ram it up to 51%. That worked, then it responded. I don't think that's normal for a PT6 though. I think my FCU was just F'ed up. Anyone else ever have this happen?