Wiggly Prop

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Mtns2Skies

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Mtns2Skies
I've got a 82" McCauley C201 that was last overhauled in 1983 and is original to the aircraft with 3000TTSN. Doesn't leak a drop of oil, but it's wiggly. I've been feeling a few other props and it's REALLY wiggly compared to them. One of the tips can probably move about 1/4" and the other probably about 1/8" (axial along the thrust line of the aircraft). I have a brand new Hartzell on order but it doesn't arrive until December. I've flown behind this prop for about 300 hours... it's probably fine for a few more months... right... RIGHT?
 
I'd suspect that the McCauley service manual for your prop would have a specification for max "wiggle", maybe you can (or have your A/P) consult the manual to see if it is within service limits?
 
Interesting. Looks like that's just how McCauley "threadless" props are. Shortest most successful PoA thread in history.
 
Awesome, I just learned a new technical term. According to the Service Letter, the proper terminology is “wobble”, not wiggle, or wiggly. Haha! Thought for sure they would have called it something way more complicated sounding.


Blade shake is defined as the tendency for the propeller blades to wobble slightly when the tip is physically moved by hand (lead edge to trail edge; see Figure 1).
 
"Normal" or not, a wobbly prop blade would take a certain % of my brain wattage during flight, even though I know it's certainly not wobbling during operation -- the lizard brain would only be imagining the exotic death spiral I was flirting with and how many rotations of that "2 of 3" blade prop would it take to jerk my motor clean off of the mounts.

:eek:
 
If it hasn’t fallen off, it’s probably fine. I mean, if it like fell off in your hands then you probably need some shims or something.
 
Mtns2Skies said:
I've got a 82" McCauley C201 that was last overhauled in 1983 and is original to the aircraft with 3000TTSN. Doesn't leak a drop of oil, but it's wiggly. I've been feeling a few other props and it's REALLY wiggly compared to them. One of the tips can probably move about 1/4" and the other probably about 1/8" (axial along the thrust line of the aircraft). I have a brand new Hartzell on order but it doesn't arrive until December. I've flown behind this prop for about 300 hours... it's probably fine for a few more months... right... RIGHT?
Click to expand...

I love it when owners want an opinion, as long as it fits what they want to hear.
"Do as you wish!".
 
JAWS said:
I love it when owners want an opinion, as long as it fits what they want to hear.
"Do as you wish!".
Click to expand...
Well, no. clearly humor was lost here. I have another spare C66 sitting in my basement I could put on at anytime, but not sure if its worth the hassle if mine will be fine for another few months until the Hartzell Scimitar prop arrives.
 
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Mtns2Skies said:
I've got a 82" McCauley C201 that was last overhauled in 1983 and is original to the aircraft with 3000TTSN. Doesn't leak a drop of oil, but it's wiggly. I've been feeling a few other props and it's REALLY wiggly compared to them. One of the tips can probably move about 1/4" and the other probably about 1/8" (axial along the thrust line of the aircraft). I have a brand new Hartzell on order but it doesn't arrive until December. I've flown behind this prop for about 300 hours... it's probably fine for a few more months... right... RIGHT?
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First, you should not be wiggling another man’s tip. Second, when comparing your wiggly one to another’s it’s best to use bigger numbers than 1/4”. Third, just send it. Fully.
 
Mtns2Skies said:
Well, no. clearly humor was lost here.
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Depends on your point of view considering there are people who post very similar questions on PoA and are dead serious for an answer. Regardless any time excessive play is perceived its best to find out how that play is actually measured. Unfortunately I've known several individuals who sent off props for repair for the same thing insisting theres something wrong only to get them back with same play.
 
Bill said:
https://mccauley.txtav.com/-/media/...hash=90E20FBE69AB7A2CBE010DAE0FBE5E860CE52C2B
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texasclouds said:
If it hasn’t fallen off, it’s probably fine. I mean, if it like fell off in your hands then you probably need some shims or something.
Click to expand...

JAWS said:
I love it when owners want an opinion, as long as it fits what they want to hear.
"Do as you wish!".
Click to expand...

So let's look at this document above:
  • Is it an AD? - Nope!
  • Is it an SB? - Nope!
  • What is it then? Well, it's an addendum to the McCauley service manual regarding blade shake and twist.
So, if this were kinda important, it would have been an SB. If it were really important, it would have been an AD. It is neither.

The only thing I don't like is the wording on what to do if the blade shake (wiggle, wobble, angle of the dangle, whatever) exceeds 1/8" at the tip of the prop: "If, however, blade shake exceeds maximum movement allowable, it should be reduced, when convenient, by inserting shims in the blade assembly by an FAA-approved propeller repairman."

That quoted text is directly from the service letter. So, what time frame is "when convenient"? Tomorrow? Next week? Next month? Next year?
 
Mtns2Skies said:
clearly humor was lost here.
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Not completely. I see what you did here.
WigglePop%21.jpg

 
Bill said:
The only thing I don't like is the wording
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Think of the wording as an advisory which this is all it is. Sometimes when an item has a "feature" that gains a non-maintenance related following, the OEM will issue a document to explain it so as to reduce any unnecessary shop visits. Have seen the same with certain gear-backlash perceived issues, helicopter T/R feather bearings play, etc. As the letter stated the play is the "natural result" of the fabrication process.
 
The play would not bother me, 3000 hours and 40 years since overhaul would scare the hell out of me! How does the annual get signed off? All McCauley CS props have a 60 month over haul requirement
 
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Jeff767 said:
How does the annual get signed off? All McCauley CS props have a 60 month over haul requirement
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FYI: overhauls are not part of the airworthiness limitations section so for most Part 91 aircraft the prop overhaul is merely a recommendation vs mandate similar to an engine recommended overhaul. So signing the annual is not affected unless the owner chooses to follow the OEM recommendation.
 
Bell206 said:
FYI: overhauls are not part of the airworthiness limitations section so for most Part 91 aircraft the prop overhaul is merely a recommendation vs mandate similar to an engine recommended overhaul. So signing the annual is not affected unless the owner chooses to follow the OEM recommendation.
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If operated only part 91 you are correct. Still I can’t ever see a competent IA signing off a annual with the prop 35 years and 1800 hours past TBO. The liability to the owner would also be beyond huge if the aircraft suffered a prop related accident. If the IA failed to note in writing the prop issue he is going to be in court also.
Let’s not even mention what it says about common sense and the rest of the maintenance on the aircraft. Time based TBO’s get exceeded all the time but 35 years?
 
Jeff767 said:
Still I can’t ever see a competent IA signing off a annual with the prop 35 years and 1800 hours past TBO.
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Jeff767 said:
If the IA failed to note in writing the prop issue he is going to be in court also.
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It's the owners ballgame, not the IA's and has nothing to do with competency on the APIAs part. It's simply the rules that must be followed. Now if the APIA determines the prop/engine condition is an airworthiness issue then he can note that as a disc but still sign off the annual. However if the owner chooses not to follow the OEM overhaul recommendations it does not fault on the APIA from a regulatory side nor does it make the aircraft unairworthy per the FARs. Now could a crack plaintiff's attorney try to finger the IA, sure. And they have provided they had the right jury or judge. Regardless, an APIA does not have the authority to force an owner to comply with anything. The APIA can merely refuse to perform the work.
Jeff767 said:
Let’s not even mention what it says about common sense and the rest of the maintenance on the aircraft. Time based TBO’s get exceeded all the time but 35 years?
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I think if you look at the stats you'll find a majority of private GA aircraft have props, engines, mandatory SBs, or whatever flown well past OEM recommendations by many hours and years. And more than 35 years in some cases. Whether you believe that to exceed "common sense" is strictly subjective to that individual just as those owners who pay for a $200/20 min annual or prefer hangar fairies to handle most of their maintenance issues. It is what it is.
 
Jeff767 said:
Let’s not even mention what it says about common sense and the rest of the maintenance on the aircraft. Time based TBO’s get exceeded all the time but 35 years?
Click to expand...
Engine is also decades past TBO. So far I've died on every single flight, sometimes more than once, strictly because of how old those components are.
 
Me too. The engine in the Comanche is waaaaaaay past the 12 year overhaul Lycoming says to do. I've died at least eleventy billion times.
 
Our lycoming that we finally replaced 1.5 years ago was overhauled in 1996. It went 23 years and 2250hrs.
 
Mtns2Skies said:
Engine is also decades past TBO. So far I've died on every single flight, sometimes more than once, strictly because of how old those components are.
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…and even more miraculously, you reanimated to tell us about it!
 
Bill said:
Our lycoming that we finally replaced 1.5 years ago was overhauled in 1996. It went 23 years and 2250hrs.
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You would have needed 17 more years and another 2000 hours on the engine to be where he is at on the prop. You really willing to fly your family on a engine like that. In addition engines past TBO typically don’t suffer catastrophic failures. They just get cranky, lose power and burn a lot of oil. Kind of like people. Props on the other hand tend to fail catastrophically.
 
Jeff767 said:
You would have needed 17 more years and another 2000 hours on the engine to be where he is at on the prop. You really willing to fly your family on a engine like that. In addition engines past TBO typically don’t suffer catastrophic failures. They just get cranky, lose power and burn a lot of oil. Kind of like people. Props on the other hand tend to fail catastrophically.
Click to expand...

True, while our engine was "older", the prop was not, we overhauled it shortly after buying the bird in 2007 and then overhauled it again when we re-engined.
 
Jeff767 said:
You would have needed 17 more years and another 2000 hours on the engine to be where he is at on the prop. You really willing to fly your family on a engine like that. In addition engines past TBO typically don’t suffer catastrophic failures. They just get cranky, lose power and burn a lot of oil. Kind of like people. Props on the other hand tend to fail catastrophically.
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Yep died again. My whole family was with me too. Not just immediate, extended. All 17 members of my family died because my prop is a bit old. Bummer.
 
Mtns2Skies said:
Yep died again. My whole family was with me too. Not just immediate, extended. All 17 members of my family died because my prop is a bit old. Bummer.
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And to think I flew in your plane with a prop in this condition?!?!?! :eek::D;):p
 
You parked that death trap next to me??!?!? What if wiggly prop is contagious? Do I need to mask up my plane? Does it need to remain 6nm from the nearest airplane?
 
EdFred said:
You parked that death trap next to me??!?!? What if wiggly prop is contagious? Do I need to mask up my plane? Does it need to remain 6nm from the nearest airplane?
Click to expand...
It's a sexually transmitted disease... I didn't see what our planes got up to while I was on the beach so idk. As always, wrap your rascal.
 
Mtns2Skies said:
I've got a 82" McCauley C201 that was last overhauled in 1983 and is original to the aircraft with 3000TTSN. Doesn't leak a drop of oil, but it's wiggly. I've been feeling a few other props and it's REALLY wiggly compared to them. One of the tips can probably move about 1/4" and the other probably about 1/8" (axial along the thrust line of the aircraft). I have a brand new Hartzell on order but it doesn't arrive until December. I've flown behind this prop for about 300 hours... it's probably fine for a few more months... right... RIGHT?
Click to expand...
I would get the prop serviced. It has greatly exceeded TBO.
 
Stand next to a parked airliner on a breezy day and listen to the clackity-clack of all those loose fan blades as the engine windmills and you'll think - that can't be right, can it?
 
Mtns2Skies said:
Interesting. Looks like that's just how McCauley "threadless" props are. Shortest most successful PoA thread in history.
Click to expand...

This didn't age well.
 
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