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Propeller Overhaul. No total time?

Cardiff Kook

PATRON
Sisters, OR
First time plane owner.

My propeller was overhauled in 2017- then put on my plane with 0 hours- but log book lists “unknown total time.”

That an issue? Normal?
 
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It could matter. I had a McCauley prop on which an AD was issued that life-limited it to 10,000 hours. My prop log did not record the time on the prop at time of installation, so I had to junk the prop. Whether it matters in your case, well, YMMV.
 
There is some leeway for older fixed-pitch props. For airframes and engines you do need total time, but apparently an estimate for some older props will do. That's because a separate prop logbook is a relatively new thing for Cubs, etc.
 
If you want total time, find out when the prop was installed new (airframe and or engine log books) and add from there. Search for serial/model number for verification. Otherwise I don't see a life limitation so it should be good until it's determined to no longer be airworthy. See the attached pdf from Sensenich about overhaul times and limits.

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  • Sensenich Service_Bulletins_R-17.pdf
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It is only an issue if the IA says it is an issue! Don't look for problems, you will find them if you ask enough people. DENNY
 
When I had my PA-11 Sen prop overhauled we looked up the production date via serial number from Sensenich's web page. No idea as to time but assumed it was installed soon after then and used the PA-11's logs to estimate time in service. Prop shop asked what's the time? Given our number they overhauled it and started a log. I think now it's due every couple thousand hours for another look at. It's now on my Taylorcraft happily spinning away.

Gary
 
What do they do when they overhaul them? Does the pitch change? Do they heat-treat them? Or just dress the leading edge, check for cracks, and repaint?

In the olden days we re-did our own wood props. Easy. Can’t do that now, of course.
 
In my cases they made sure they conformed to the TCDS and provided a maintenance release, and now typically a log book is offered if TT is estimated. What goes on to do that? Ask them. But for one prop it involved removing surface corrosion and any prior covering, re-profiling and leading edge clean-up, and ensuring dimensional sizing plus pitch distribution per blade. Props shrink both chord and lengthwise with usage thanks due to field maintenance, and that eventually gets them hung on the wall as ornaments.

Gary
 
In the olden days we re-did our own wood props. Easy. Can’t do that now, of course.
Where does it say an A&P can not redo the varnish on wood props?

§ 65.81 General privileges and limitations.
(a) A certificated mechanic may perform or supervise the maintenance, preventive maintenance or alteration of an aircraft or appliance, or a part thereof, for which he is rated (but excluding major repairs to, and major alterations of, propellers,

FAR 43 - Appendix A

Major Alterations, Major Repairs, and Preventive Maintenance

(3) Propeller major repairs. Repairs of the following types to a propeller are propeller major repairs:
(iv) Retipping of wood propellers.
(v) Replacement of outer laminations on fixed pitch wood propellers.
(vi) Repairing elongated bolt holes in the hub of fixed pitch wood propellers.
(vii) Inlay work on wood blades.
 
My old prop guy started doing them in WWII. After taking several props to him that were flatter than marked I asked him how that could be. He said the pitch flattens out from static run ups. I watched this video years agon on metal prop overhaul and found it interesting.
 
Here's one copy of the Sensenich Propeller Repair Manual 590. It may not be the current document or include all the service supplements. It does show what might be done during periodic overhaul:

https://www.yankee-aviation.com/docs/Sensenich repair manual SPRM 590.pdf

Here's are copies of McCauley's similar Owner's Operator's Manuals: TBO and general inspection starts around p. 601 and repairs around p. 801 in the first link. And again suggested typical fixed pitch TBO is 2K hrs or 72 months. They may not be current and include revisions:

https://mccauley.txtav.com/-/media/mccauley/files/manuals/mpc26ow.ashx
https://mccauley.txtav.com/-/media/...hash=3CC719C7BCECB182B72C590917E330A1F81817EE

Gary
 
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Wonder how long I need static run my 82-43 to turn it into a 40?;-)
Kevin
I heard that some pilots will even start with a 82-40 just to save the environment from all that excess fuel burn from trying bend it by static run up:wink::wink:.
DENNY
 
Prop service times don’t apply to private owners, right? Why would a private guy care what the time is?

Maybe because 91.417 requires it! That said, I would guess that about 80% of engines and props have “made up” total times. More often than not, when someone sends a prop or engine in for overhaul, the neglect to send the log books. The prop or engine gets sent to a new owner with a statement to the effect of time continued, 0 SMOH. Then it is up to the new owner to guess what the total time is.

I used to get props from an overhaul shop. He could build a prop from parts less expensive than buying one from Hartzell or McCualley. It would have a new hub and serial number, but was an overhauled prop since he was only a repair station and couldn’t build “new” props. Try and figure out how t establish time in service when the item tracked is new, but many of the other components are used!


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I think most of us would do out best to determine total time on a prop if nothing was in the logs..........and if a total time figure was in the logs how do we know it's accurate? We assume that and carry on.
What options are there? Throw away a good prop?
 
I think most of us would do out best to determine total time on a prop if nothing was in the logs..........and if a total time figure was in the logs how do we know it's accurate? We assume that and carry on.
What options are there? Throw away a good prop?

Exactly, look at he prop, what condition is it in? If just back from the prop shop, assume some multiple of 2000 +- hours and there you have it. Same thing with engines with no total time. Use your best judgement. For the most part there are no life limited parts on engines and props so there is no degradation to safety. Just checking the box for the FAA!


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