mistarose

Will the prop on the Seminole feather without bringing the blue knob all the way back? When? Where? How?

Laxrox43

Nope, if you neglect to "feather" (retard the prop lever to the stop) the propeller will not feather. When the engine RPM slows below the specified RPM (750 RPM if I remember correctly), locking pins engage, and prohibit the propeller from being able to feather fully...now if you were hear in person, I could draw you a killer Picaso on the markerboard

ATP guys/gals fly these things way more than I have...so maybe they could give you specifics

Have fun with this add-on Mista...and get your PIC so you can get your MEI ASAP! --- just a suggestion...

Lax

mistarose

Roger that, so the only way it could feather w/out moving the blue knob into feather is if the low pitch locks some how failed and didn't "lock?"

Thanks for your input, its always welcomed.

Laxrox43

Yeah...but I have never heard of any problems or AD's about the prop locks on the Hartzels...

Any A&P's on here want to chime in on this one?!?!

palgia841

Sure it will, if you have a failure in the oil system. If the pressure drops fast enough, the prop will feather.

TankerBob

Thats what I thought.. but its been so long I didnt want to say anyhting

Laxrox43

...me neither...

NE_Pilot

Yea, if you lose Oil Pressure fast enough it will feather, otherwise you have to pull back the Prop Control.

If you do not pull back the Prop Control to Feather before the RPM reaches 950 you will not be able to feather because of the Feather Locks, which go into place at 950 RPM due to centrifugal force.

TankerBob

Hmm thanks! I guess I forgot that.

mistarose

Lets get this straight, if you loose oil pressure, the propeller will only go into feather w/out manually feathering it if the oil is lossed quickly. Why does it matter how fast/slow you loose the oil pressure in the system?

Whats the proper name for these locks that engage somewhere between 700 and 950 rpms? Do you prevent these pins from locking by moving the prop lever past the feather detent? Because at some point you will be reducing the RPMs past the 700-950 range when they are supposed to engage.

Now to a related topic, during the runup, what are we checking during the feather check? We increase RPM's to 1500, then move each prop lever individually to the feather detent momentarilly and back to full forward again. I have been told and believe that we are verifying the feather locks do not engage, and the prop acts as if it is going to feather (rapid decrease in RPM and whop whop whop). I have also been told we do not know if its the locks or oil pressure keeping them from feathering. I am very confused and will figure all of this out eventually during ground training, but am interested in others thoughts.

Thanks in advance!