Constant Speed Low Pitch Blade Stop and Governor adjustments. Skybolt fasteners.
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- čas přidán 28. 01. 2023
- Vic from Base Leg Aviation explains how to adjust the governor and low pitch blade stops on constant speed props (MT and Hartzell). He also shows the Skybolt fasteners on his RV-10 and does a quick explanation of how to install them.
@baselegaviation1614
www.baselegaviation.com
Very useful. Thanks Vic.
Newer kits have inserts and magnets that make the installation much easier.
Thank you Vic. How about skybolt adjustments howto? How to know correct vs incorrect adjustment?
Great video. Can you do the static run-up with the spinner off?
yes, but be careful and remove the spinner prop blade cutout pieces.
Thanks for the great Video. I have an RV7 with 130hrs on it. When I am on take off at full power and fine pitch I am getting surging and a 50-80RPM drop and then correction on the take off. After getting climbing and gaining airspeed the surging stops and everything works properly? Is this possibly caused by the prop not being set-up properly from new ? I am planning on having my AME take a look, but just wanted your opinion. In all other phases of flight the prop is working correctly.
yes. it sounds like the governor is taking over too soon.
Pull your spinner, put an Alan key in the hole, and crack loose the 9/16 nut. Then holding the nut, turn the Alan key 2 and 1/3 turns clockwise “in”. Then re-snug the 9/16 nut. Replace the spinner and test the static RPM with the brakes set and flaps up. You should see 2650 and no surging.
G,day from Sydney Australia.
You mentioned overspeeding the engine >2700 3000 RPM would require an engine "teardown". What internal damage would you expect to see?
Different from a prop strike: no force only extra speed?
* Crankshaft position
* Connecting rod attachment
🌏🇭🇲
I’m pretty certain I mentioned propeller tear down, not engine. sorry for the confusion.
Most recent flight after reinstalling IRANed governor and Hartzell CS prop: 1st takeoff: 2730 rpm, then immediately 2680 (no intervention by prop control); 2nd and 4th takeoff: 2680 rpm; 3rd takeoff: 2760 rpm, then immediately 2690. Slightly irregular, right? Good enough or should I follow your adjustment procedure?
Yes, you should do the adjustment. Sounds like your governor is controlling it.
Agreed with Vic.. your governor is trying to adjust your prop to control your RPM. You need to increase the low pitch stop blade angles, then you should only see 2650 or so initially on takeoff.. the RPM will be steady and smooth as you accelerate down the runway without the RPM hunting like it’s doing now. You’ll also find that you’ll get better power off glide speed after adjusting it.
Okay,, Vic. I trust your experience and knowledge. Many of us RV pilots have Hartzell c/s props. What is better if we lose the engine due to fuel starvation, the engine is not seized and the prop is still turning. What would you do with the prop control to get the most range at best glide airspeed or does it really matter?
You bet it does. Pull it ALL the way back. It will really extend your distance. Try it sometime when on final. You won't hurt anything. With power back pull the prop all the way back. It will have a wow factor. Guaranteed!
@@baselegaviation1614 What I was getting at is, if I were to pull the prop control back on a non-running engine, will a windmilling c/s prop turn at sufficient rpm to maintain oil pressure to keep the blades in a semi-feathered condition? I have only one engine and never had the guts to shut it off and feather the prop at the same time.
yes
@@garyvanremortel5218depends.. on some aircraft, I can’t notice a difference pulling the prop back at glide speed.. sure at 120 knots or more, you can really feel it, but on some installations at glide speed, there’s no change. If you have a real engine failure where you blow a hole in the case, blow an oil line or some reason you can’t move the prop angle, you’ll be better with the low pitch stops set properly.
@@thomasaltrudaMy low pitch stop is properly set. I find with my RV-6A with Lyc O-360-A1A I always get more thrust if I bring the rpm down a bit from 2680 that the stop produces to 2600 or 2550 with the prop control. I get a bigger bite of air and am still well up on the torque curve. This is especially true in high density altitudes as I leave the throttle full in, lean for best power and bring the prop back a bit on the takeoff run. You can feel the added thrust in the seat of your pants.
Hartzell says 100RPM fpr 1/2 turn.
I still have some confusion about this. If the pitch stop is designed to prevent excess RPM then why would the governor come into play to keep RPM below 2700?
You want to keep the prop from overspeeding at full throttle, such as during climb. Basically, you set it up to act as a fixed pitch prop and then let the governor take over at 2700-2720 RPM's. IF you have the governor taking over too early, then if the governor should fail, you will have a massive overspeed, sometimes necessitating a tear down of the prop.
@baselegaviation1614 so the pitch stop is adjusted for static run up, and the governor for in motion. I think
correct
How much to IRAN governor?
That would vary by type of governor and the shop. You will have to ask.