My governor is the same McCauley Prop Governor part #DCF290D7X/T3.
My Hartzell Prop Model is HC-H3YF-2UF-FC7693DF/SM17 (3 Blade Feathering Prop, Scimitar D-3273-2P).
The prop can be put into feather position on the ground if you maintain 1400-1600 minimum RPM with higher engine MAP (throttle control) than the usual idle settings.
While flying, the placement in full feather at idle will stop the prop (completely stationary). It will not come out of feather without new cranking (I do not have an accumulator).
The engine can be restarted with the prop in feather by cranking it a bit more than usual, sending the blades into flatter pitch, given the crank more ability to turn the blades. This occurs because crank yields engine oil pressure, and the governor amplifies pressure into the hub. This can be demonstrated on the ground.
An inflight practice engine stoppage in full feather postion obviously requires a HOT START technique, but you don't have the same auditory clues (headset/ANR on, 120 KIAS), so one needs to study the guages for proper fuel/pressure indicators to guide the control choices (while you also fly the plane).
When you crank the engine inflight, your cranking electrical buss will be reduced in voltage as the starter pulls the amps. If you have avionics on this same buss (especially a MFD or PFD), they will go dark during the restart, depriving you of the engine page you need to be watching. That's quite startling at first. When the prop begins its movement out of feather, the wind will catch it and it will begin to turn at ~400 RPM: you're almost there with the restart.
I first did this engine stoppage during HPAT recurrency training with Ron G (who also taught me his OSH hot start technique) so I could understand the glide performance of my Lancair IVP when engine broken. I then practiced this a few more times afterwards, also to determine the power setting for a simulated engine out at an appropriate glide performance, again for more thorough practice (minus the actual stoppage). Now I can simulate engine out more realistically with proper glide behavior (without actually stopping the engine).
I'm not sure about the prop's racing qualities or the two simultaneous occurances aspects of what you were told, as I was not told this.
I also don't understand how Hartzell could make a prop but not have a recommended Governor to govern it.
Our HPAT and LOBO instructors should continue to weigh in on the subject, as we all should keenly listen to their professional advice. Disclaimer: I did not stay at a Holiday Inn last night.
Jeff L
Barry Knotts" <bknotts@buckeye-express.com> wrote:
Jeff,
I think I have the same full feathering Hartzell prop on my IV-P (HC-H3YF-2UF). The governor is a McCauley #DCF290D7X/T3. I can control the speed, but I can't feather this prop with the prop control. I was told at one time that this prop is designed for racing and it only will go to full feather if two things occur simultaneously; loss of oil pressure and RPM above 1200. Then it locks in feather and you do whatever you need to do to get on the ground. The only way to unfeather it at that point requires attaining 1200 RPM WITH oil pressure. Tough to do with the starter, the engine must start and produce oil pressure...while feathered.
These two things conditions for feathering should only occur together if you have a catastrophic loss of oil pressure with a windmilling prop (or driven). Otherwise, you would have the prop feather every time you shut the engine down.
So my question is: How did you get it to feather? Do you have a different prop governor? I called Hartzell once and they said that they did not have a recommended governor for the prop. (That seemed a little strange.)
Inquiring minds....
Barry Knotts
Lancair IV-P, N4XE
On 6/19/2011 11:30 AM, liegner@earthlink.net wrote:
I have practiced engine out glide with my full feather three blade
Hartzell prop (Model number HC-H3YF-2UF) in the full feather position
and fully stopped.
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