Propeller Feather Gates.

[JMH]

Thread resurrection!

Considering purchasing an O2, and determined that it had the wrong governors installed so un-feathering is not possible (no unfeathering port on the installed governors) and possibly the unfeathering controls were disconnected. Anyone have any experience with this? or recommendations?

If we do indeed purchase and have the correct governors installed (and assumedly the unfeathering controls), what is the best way to check that it all works - complete feather and unfeather cycle? @Paul462- it seems to work fine in the air, ever accomplish it on the ground with similar results? Thanks!

[JimC]

I was checking out a new pilot in my plane the other day and the pilot fully feathered the rear prop during the feather check. The engine kept running (slowly.) We were able to get it back into normal ops without shutting down.

[mshac]

Originally Posted by JMH

Thread resurrection!

Considering purchasing an O2, and determined that it had the wrong governors installed so un-feathering is not possible (no unfeathering port on the installed governors) and possibly the unfeathering controls were disconnected. Anyone have any experience with this? or recommendations?

If we do indeed purchase and have the correct governors installed (and assumedly the unfeathering controls), what is the best way to check that it all works - complete feather and unfeather cycle? @Paul462- it seems to work fine in the air, ever accomplish it on the ground with similar results? Thanks!

02s had unfeathering accumulators, and different governors. Perhaps yours had the accumulators removed, but still has the old givernors? Or if in place, the accumulators need a good nitrogen charge, about 90psi IIRC.

[JMH]

Could be... We have it in overhaul at the moment and the mechanic tells us it has the wrong governors (both props). We'll have to actually dig into the airplane to see if the connection is still there (to actuate the accumulators - not sure how it is mechanized), we obviously want to get the correct governors installed and would like the ability to unfeather it if it is every needed.

Feather/unfeather on the ground seems to be some debate weather that causes undue stress of the aircraft (perhaps that is more of an issue WITHOUT accumulators to help with the unfeathering?) Thanks!

[mshac]

JMH, there are two correct accumulators for sale on Ebay right now. You could buy both of them for under $400. Not a bad deal if that's the direction you decide to go.

[JMH]

Thanks! Good idea...

We went ahead and bought the maintenance manual for the O2 and it actually has a operational checkout procedure for feathering/accumulator - the key piece is to to go to idle-cutoff and kill the Mags when the rpm starts dropping... and then leave it undisturbed for 6-8 minutes. Then move the prop lever to full increase and observe blade angle change.

More research to do.

[mshac]

Originally Posted by JMH

Thanks! Good idea...

We went ahead and bought the maintenance manual for the O2 and it actually has a operational checkout procedure for feathering/accumulator - the key piece is to to go to idle-cutoff and kill the Mags when the rpm starts dropping... and then leave it undisturbed for 6-8 minutes. Then move the prop lever to full increase and observe blade angle change.

More research to do.

Not gonna have any blade angle change from a non-running motor UNLESS you have accumulators. You can always unfeather props on the ground with a wooden "prop blade wrench".