[STEVE]

STEVE on November 24, 2025 at 10:11 am #25677

Good morning,
Todd, American Prop told me that it your prop is airworthy and the vibration limits are “in the green” that it can attempt to smooth it out, but there’s no guarantee it will help.

What is the imbalance reading? How many IPS is the lowest the tech can get during the balancing procedure?

Steve

[David]

David on November 22, 2025 at 10:38 am #25676

Thanks Steve,
The prop was officially overhauled by H&S May 2018. It was found to have been repitched, and they pitched it back to stock
It was checked again by H&S Sep 2020 where they did a minor rebalance (painted on blade)
It has 1010 hrs since the 2018 overhaul
Before we go to the effort of taking the prop off and sending it somewhere, were those numbers out of line? As I mentioned, the balance is in the “Green”, so unless there is a real reason to be invasive, I’ld rather not go through that effort.
Thanks again for the help

[STEVE]

STEVE on November 18, 2025 at 11:59 am #25675

Hi David,
My prop guy, Todd at American Propeller asks when was your prop last overhauled or if it hasn’t been overhauled when was it new?

And which shop did the “checking’ you have referred to? I believe Todd wants to talk to the shop to learn what was done there.

Todd told me he would be happy to look over your prop and then told me that the company policy at American is if it’s been over 10 years since last overhaul or since new, their policy requires that they overhaul the prop.

He also said that in order to get the overall diameter of a prop they mount it in a centering fixture prior to measuring.

Best,
Steve

[STEVE]

STEVE on November 17, 2025 at 9:20 am #25672

Hi David,
Excellent. I’m sending your post to my prop expert this morning.
Will relay his response to you on this forum as soon as I get it.
Good job,

Steve

[David]

David on November 15, 2025 at 3:02 pm #25671

Steve,
The prop is Sensenich M76EM855-0-60
Ser # 26569K
One blade measures 32 1/2 ” from the tip to the ring gear
That blade also has a chord of 4.37″ at 6″ from the tip
and 5.698″ at 16″ from the tip.
The other blade measures 32 5/16 ” from the tip to the ring gear
That blade also has a chord of 4.406″ at 6″ from the tip
and 5.66″ at 16″ from the tip.

Hope that was what you were after

[Eric Parks]

Eric Parks on November 7, 2025 at 6:41 pm #25658

The Sensenich prop upgrade sounds interesting. I wonder how much advantage it wll bring to the Cherokee? I would like to think it would be a little better climb and/or crusise speed and probably get rid of the RPM caution range typical in the O-360 with a metal fixed pitch prop. With the added benefit of lighter weight that could make a very nice upgrade for the Cherokee 180.

[STEVE]

STEVE on November 6, 2025 at 9:48 am #25653

Hi David,
In order for me to get you more guidance, I’m going to need to know he prop part number, the variation between the 2 blade lengths and the over all diameter of the prop. 
I am not a fixed pitch prop expert but it seems as though different length blades would make a huge difference in the amount of thrust generated by the two blades. 

Give me that info and I’ll do my best to get you the correct answer.

Best,
Steve

[David]

David on November 4, 2025 at 4:16 pm #25652

Thanks for the response Steve,
I have had the prop serviced twice, and it is “in spec”. However I can. measure a difference in the blade lengths, although again it is in spec. I’m ok with it for now, but was looking for some other options. I will look at the Sensenich options.
Thanks again

[STEVE]

STEVE on November 3, 2025 at 9:32 am #25650

Hi David;
I just spoke with Sensenich to verify what I believe; that is that you should be able to send your fixed pitch propeller to a prop repair station to get the pitch in each blade matched. While it’s there the prop shop will do what’s called a static balance.

Unless the prop shop discovers that your prop is worn beyond limits, that’s the easiest and least expensive “fix” for the vibration problem.

Sensenich is seeking a STC for the installation of its composite ground adjustable propeller for your Cherokee.
The composite prop will weigh less than your aluminum prop and it will have an option for you, the pilot to change the pitch of the prop while on the ground.

If you need a shorter ground run you can adjust the prop for that. If the runway length is not a problem and you want to cruise faster, click click another adustment will take care of that need.

Sensenich believes that STC will be approved in the Spring of 2026. Right now the cost of the composite ground adjustable prop is around $4500–I don’t know what it will be after the STC is granted.

My advice is to send your prop to a prop shop for a tune up. Ask the shop to troubleshoot and advise. Just about the only way that step will back fire is if the prop is worn beyond limits.

Let me know what you decide.

Steve

[David]

David on November 1, 2025 at 11:35 am #25649

I have a PA28-180 with a fixed pitch Sensenich Propellar. I suspect that although it is “in spec”, it is just enough out aerodynamically that it creates some vibration. After many balancing attempts, we can get it into the “green” but just barely. The balance point moves with RPM (although that could indicate a mount issue, the mounts are relatively new and the engine cradle checks out.) so I have some reason to believe one blade is a tad off from the other.
So….. I was wondering if there was an option to upgrade to a newer technology fixed pitch prop. There seems to be several options for experimental, but have not seen one for certificated. If there is something out there, I would be interested.
   Thanks!