Rear Prop Feathers after shut down

[cessna02337]

Hey Folks....Have an issue with the rear prop after shutdown, goes into full feather....I was told to troubleshoot governor (both freshly overhauled)....also replaced both accumulators as well...Props are 60 hours from last overhaul as well....any thoughts....Tom

[skymstr02]

The only time that I had this happen, it was a low engine oil pressure problem. If the prop speed is over 1200 rpm, the feather pins should be engaged (INTERNAL IN THE PROP). Oil pressure is the only thing that keeps the prop out of feather, and with low oil pressure, the spring tension in the prop overcome the low pressure.

[stackj]

I just had my rear engine overhauled this summer. At completion of the overhaul and after the first flight the mechanic went through the fuel system setup procedure. He ran the engine long enough on the ground on a 95 plus degree day to overheat it, causing low oil pressure. The prop went into feather.

He used paddles to reset the prop blades (McCauley says not to, but I don't know how else you'd go about it.) Everything ran and worked OK afterwards.

The point is that low oil pressure will cause the prop to feather if the RPM is high enough that the stops don't engage.

Make sure your engine is properly baffled and is getting adequate airflow.

[cessna02337]

Adjusted the governor per the prop overhaul shop's guidance (governors were freshly overhauled at annual), seemed to do the trick....will not be happy until I have several shutdowns to check if it stays out of feather...I will keep everyone posted. T

[skymstr02]

Thats good to hear Tom!