Not Bill but I made the adjustment of 2.3 turns and it now measures 2660 static. First landing with the adjustment was interesting…… I approached at my normal speed, reduced the throttle and floated further than in the past. My first thought was I did not pull the throttle back to the stop but it was. Fortunately the first landing was not on a short strip.
That sounds like your plane is now safer!! She’ll actually glide now! I prefer to go to idle on either downwind or base and glide it in.. too many planes that experience an engine failure in the pattern and come up short.
Like to see the statistics on that one too but I’ve tortured you enough. Not making a runway is all about experience and judgment. A brick can make the runway if you know your brick. Extending a glide just gives you more options, but if you haven’t the experience with it, you might float right past your target. That isn’t safer.
For those who say the proper stop gives a better glide range during engine failure, why not just slow plane down till prop stops? I find this to be about 80 kts, then it takes about 95 kts to get it spinning again Which is close to best glide speed.
It’s been my experience with a CS prop, in order to get the prop to stop, you need to go full flaps and just about stall the plane. Your example of 80 knots to stop the prop might work with a wooden fixed pitch, but a heavy aluminum prop that moves to low pitch is very hard to stop. After slowing to about stall speed, then reassuming best glide, I think you negated the benefit of trying to glide further, unless you have tons of altitude.
I guess that all depends on what kind of compression you have And if it’s a catastrophic failure, it will probably stop anyway. I was also assuming g people didn’t want to fiddle with reaching low pitch stops, this would stop them at higher speeds.
A plane with poor glide is easier to spot land, but a plane that glides further can give you more options and (in my opinion) is safer. But that alone isn’t what makes the plane safer. If you lost oil pressure, or the governor on takeoff, and your low pitch stops aren’t preset correctly, the rpm will go to 3000+ and you will have less thrust because a flat blade isn’t biting the air. Correctly set low pitch stops are like having a backup that will maintain control and some bite on the air, like a fixed pitch prop set for climb. That’s what makes the plane safer. I know someone who lost his governor on takeoff, and the plane fell on its face, no thrust, 3300 rpm. He throttled back and got it stopped on the remaining runway, melting out his caliper o-rings in the process.
Yes I agree, if there so far of to hit 3000 rpm’s, you have a problem. After my prop overhaul, I can get it to surge to 2740 but my governor is holding it to 2650 which is ok with me. what I don’t know is if the surge would be the limit if governor did fail. Anyone know this answere?
I turned my prop stop down 30 RPM To avoid a 1 second 2730 overspeed. 3/8 of a turn. It seems like it made a big difference in the engine breaking on landing. I must confess it miss it terribly. Thinking about turning it back.
Check your prop manual but on my Hartzell, that’s not an overspeed. You can run continuously at 2730. You can run much higher for limited times.
You are exactly the person that I started this thread for!! Your plane is a prime candidate for making this adjustment. The fact that you are adjusting your governor down to compensate for the surge is why I started this thread. That’s EXACTLY the wrong way to handle it. Go back and reread the procedure, you’ll probably need 2 1/3 turns on the low pitch stop screw under the spinner. Each full revolution would be 200RPM if the governor didn’t catch it, meaning if your governor failed, or you lost oil pressure from a blown line, then your prop will go to 3100+RPM!! Start with 2 1/3 turns on the low pitch stop, reset your governor back up to 2700. You should see 2650 at the very beginning of your takeoff roll, increasing to 2700 by liftoff, where the governor will maintain it for the rest of the flight.
I believe it takes a full revolution on the governor per 30rpm.. I doubt that 1/3 of a turn made much of a difference more than 10 rpm.
If you get ANY flare up that comes back down, then you aren’t adjusted right. You say your static is spot on? What do you get statically? Ideal is 2650-2670. If you are getting even a momentary 2720, then back to 2700, you also could use an adjustment.
What 540 do you have? Is it a 2700RPM engine or 2600? (The data plate on the engine can tell you this) Are you able to achieve full rated RPM on climb out? Or perhaps someone already set the governor lower then rated for some reason? I would sneak up on the governor to achieve rated rpm (I think it’s about 30 rpm per revolution on the governor screw) but you also have to make sure your prop control cable length allows you to reach the stop before bottoming on the panel. There should be a 1/8 to 1/4 gap between the blue knob and the panel at full forward. It seems that every hartzell propeller that I adjust needed 2 1/3 turns on the low pitch stop, also from others that have done the procedure report the same.
Yes the low pitch stops are 200rpm per turn on the screw. The GOVERNOR screw is about 30 rpm per turn from what I remember.. two different things.
But you say it goes to 2720, then settles at 2650ish? That’s because you are on the governor and the low pitch stops aren’t set correctly.. are you saying that statically, you get 2650ish, does this change as you go down the runway? What about at 110 knots, is it still 2650 ish? You should be able to maintain 2700 (rated) rpm in the climb. If you were to back off your governor adjustment, do you think your static rpm would change? I don’t think you are understanding or maybe you don’t want to understand, that’s fine, but from what you are saying, I believe your engine/prop combo is also a candidate for proper adjustment.
I’m an A&P and an IA, I would love to help you out. Do you ever make it out to Las Vegas? How about Oceanside? I’ll be in SNA tomorrow if you wanted to fly over..
Not quite, let me help correct it..
Each full revolution would be 200RPM if the governor didn’t catch it, meaning if your governor failed, or you lost oil pressure from a blown line, then your prop will go to 3100+RPM!! Start with 2 1/3 turns on the low pitch stop, reset your governor back up to 2700. You should see 2650 at the very beginning of your takeoff roll, increasing to 2700 by liftoff, where the governor will maintain it for the rest of the flight.
No. Governor taken out of the picture I get 2650.
That doesn’t sound right. So statically, holding the brakes with no airspeed, what RPM can you get at full throttle? That’s what we are checking here. With flaps up and brakes held, while holding the stick full back, you should safely be able to test this.
Too much!
Yes “in” on the Alan key to lower RPM statically (increases minimum pitch blade angle) I back off the 9/16 nut half a turn while holding the Alan key, then I screw IN (clockwise) the Alan key 2.3 turns, then re-snug the 9/16 nut. Typically the Alan key screw is still sticking out maybe 1/2 to 3/4 of an inch from the nylon lock nut. If you are out of threads, something funny is going on.
Ya, it was sticking out about that much before I turned it in. I’ll report what the prop shop has to say.
Prior to '08, the stop nut was a locking metal nut, which was replaced with a nylon lock nut for better sealing. An optional pitch stop set screw with slightly increased length was introduced at this time as well to account for the additional height of the nylon lock nut. It's possible you've got a tall nut with a short screw, which would limit how high you can set your low pitch. However, even in that case it is still odd that you're out of adjustment.
Hey Vic, I read your book this weekend, cover to cover. Thank you for sharing such practical knowledge! Coincidently, I have a question about the pitch stop setting on a new engine/prop combination. What is your recommendation when we need to set pitch stops on an engine that needs to be broken in? I read that setting the pitch stops might take a few engine runs but, at the same time, I know we have to limit ground runs on a brand new engine.
Good to know. Mine is pre ‘08 metal lock nut, rebuilt in ‘14 and still has the metal nut. There was a some breeze but not what I would say as windy.
Not Vic, but just control RPM using the gov as normal, throttle up slowly so the gov has time to control RPM.
Thank you Walt, appreciate the insight! I also noticed that my prop governor came with a small paper slip saying that the top RPM was set to 2430. Is this another stop adjustment that I should be looking at? before or after break in? Appreciate any advices on that too
Not sure about that but I don't think that relates to prop RPM necessarily. Which gov is it?Thank you Walt, appreciate the insight! I also noticed that my prop governor came with a small paper slip saying that the top RPM was set to 2430. Is this another stop adjustment that I should be looking at? before or after break in? Appreciate any advices on that too
Measured blade angle in the bench. Something like 15. Set to specs, moved to 12 ish. Nothing appears to be amiss.
Good chance, and for sure if it's a Hartzell governor, that the RPM on the test report is the governor RPM, which is (typically) geared down from the engine RPM (gear ratio varies based on engine model). And, again if it's a Hartzell, that RPM is adjustable (within reason) via the high RPM stop on the governor (what you hear people talk about as adjusting the governor). As long as it's close and you can get to the power settings you want/need, I wouldn't worry about fiddling with it until after break in.Thank you Walt, appreciate the insight! I also noticed that my prop governor came with a small paper slip saying that the top RPM was set to 2430. Is this another stop adjustment that I should be looking at? before or after break in? Appreciate any advices on that too
I'll check on this more in depth tomorrow when I'm in the office; what is the exact model prop and engine (+mods?) you have?
Out of town but will get that to you. Spoke with Ollie? Earlier today. He was a huge help. I am so impressed with Hartzell. Call, get a real person who knows what they are talking about, just can’t say enough of their support.
Yes, it is a Hartzell governor. Thanks for the explanation
HC-C2YR-1BF/F7496
Ok, for that specific combination, I would expect you to end up somewhere around 13.5°-14.0° as your low pitch setting, and this should be well within the nominal adjustment range for this collection of components. And from your measurements, it sounds like you should have enough adjustment to capture the required setting, and adjusting the screw is adjusting the angle so the adjustment is functioning.
Thanks Paul, it's my pleasure. I'm a big advocate of the education piece of the "education or recreation" privilege we get to enjoy, and I've certainly benefited from others sharing from their own expertise and experience, so I'm happy to contribute where I can.
Should be true. But the real benefit is that should the governor fail, you have a shot at continuing on to an on-airport landing without grossly over-speeding the engine.
Yes! Definitely should glide better! Now imagine if you had an engine failure or blew an oil hose, and weren’t able to increase glide by pulling the prop back, isn’t this safer now that it glides better? Glad you were able to figure out how to adjust the WW200.
