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Thread: Sell a prop with no info?

  1. #1

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    Sell a prop with no info?

    I figured someone here would know. I sold a couple of props this year already. One that I had no info for...went to a guy with an experimental.

    The other.. had an 8130, and logbook. (seems guy lost the logbook in shipping, but I had emailed him scans of all)

    Anyway.. those were props from my old Cessna 140.

    I just put a whirlwind on my experimental cub. I bought the plane late last year. It had a sort of 'build book' with it. A few manuals were in there. It has an airframe log and engine log with the appropriate entries and such. It never had, or if it did... I didn't get the prop log. I doubt it had one. I'm sure there was a box somewhere with all the receipts.. but the builder passed and it wasn't saved.

    It's a sensenich 74DM-054 . Serial number K13408 . Is there any way to tell manufacture date from that info?

    I SUSPECT the prop was new, and it had just a couple tenths over 100 hours on it in (when I removed it this week) the 9 years since the plane was first flown. The paint is barely missing off the leading edge. I suppose it's possible it was overhauled, and painted. If the serial number doesn't yield info..... What then?

    I won't have a prop log book... unless I have the mechanic just make one saying.. I pulled X prop off X plane on X day with 100 hours on it. That's not gonna be an 8130.

    I suppose that someone buying it COULD do a full overhaul and then they'd get a zero time prop???

    I'm stabbing in the dark here. Anyone have relevant experience?

    Jason
    Last edited by JP11; 06-20-2019 at 07:49 PM.

  2. #2

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    Back in the old days nobody bothered. Now you have to have total time in service of any prop.

    Personally, I would ignore it a bit longer. If your IA is OCD, you might wind up buying a used prop with a logbook. They are out there, but rare and probably suspect.

  3. #3
    www.SkupTech.com mike mcs repair's Avatar
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    Other than air taxi planes I doubt anyone even pays attention to props or which is installed . Since some people might got through 3 a year......


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  4. #4
    BC12D-4-85's Avatar
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    I had one Sensenich on a plane with no prior records. We estimated the use from the plane's TT logs and approximate prop manufacturing date (S/N based - assumed it was installed that day). Sent it to Merrill Field Propeller had it overhauled and log, AD's complied with (yes there was one for surface corrosion under old lacquer finish), and 2000 hr TBO started. Still whistling down the road.

    Gary
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  5. #5

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    Thanks.. that's kind of how I 'guaranteed' the other ones I sold. Pretty much said.. IF you want to take it to a prop shop, and pay for a full overhaul.. I'll buy it back if it won't pass. I figure someone with a o320 will want the prop, spinner, and insulated prop cover. I'll get some pictures and list it for sale.

  6. #6

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    So, question: does a prop overhaul allow a statement of zero time? You do know you need total time.

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    OH kinda makes it "new" if still in spec. but probably not for a certified install. It's my understanding after reading the AD on the initial 76EM series that cracks start on the surface and an OH will probably remove them? Some IA's will let it pass, some will not. Probably best to hang it on an E-AB but alas value is about 50%.

  8. #8

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    Quote Originally Posted by bob turner View Post
    So, question: does a prop overhaul allow a statement of zero time? You do know you need total time.
    Bob, the only way to Zero time an aircraft component is to “Rebuild” it. Per 43.3(j), only the manufacturer can rebuild an item. Based on that, an overhaul does not zero time it, only time forward.


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  9. #9

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    So technically, an old prop that comes from a prop shop with"total time unknown, time since overhaul zero" is unairworthy?

    I think that is what the original poster was getting at. If you sell a used prop, include a logbook that says "total time from flight records 2310.4 hours". If you cannot do that, the prop becomes experimental.

    I bet not 5% of all fixed pitch props in use today have a known total time.
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  10. #10
    skywagon8a's Avatar
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    What regulation says that old props have to have a log book generated for them to remain airworthy? There is a date at which all new props must have log books but what about the thousands of older ones? There was never any documentation following the props as they bounced from plane to plane.
    N1PA
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  11. #11

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    Quote Originally Posted by skywagon8a View Post
    What regulation says that old props have to have a log book generated for them to remain airworthy? There is a date at which all new props must have log books but what about the thousands of older ones? There was never any documentation following the props as they bounced from plane to plane.
    91.417(a)(2)(I) requires total time for airframe, engine and prop. That said, there are no life limits or required inspections/overhauled on fixed pitch props. No requirement for a prop to have a separate maintenance record, just that records are maintained. From my perspective, if it were to go to overhaul, estimate based on engine overhaul interval works. I just got a prop for my airplane with no records. Log will show something around 2400 hours. Close enough to satisfy the requirement for total time.


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  12. #12
    n40ff's Avatar
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    But the fact seems to remain that we seem to treat the prop different than the air frame/engine. An estimate of TT is not allowed is it?

    I also ask, when did the propeller log for Fixed pitch props start? I owned several certified aircraft in the 70's and do not recall a single propeller log book.

    Jack

    PS. The theory that a "un airworthy or non certifiable" propeller is "ok" for experimental is dubious at best IMO(although I run more than one). Fixed pitch props on average do have a finite life. As they are overhauled, after a couple times they become too short and/or too thin to be certified. After that their harmonics are problematic/unknown and the operative question becomes,

    Do I feel lucky?

  13. #13
    wireweinie's Avatar
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    Big difference between a fixed pitch and a constant speed prop. A log on a constant speed is an obvious need as they have serialized blades and hubs and lots of moving parts. A fixed pitch has no moving parts, no life limits beyond condition. With no hour/calendar time limits and no overhaul requirements, what info is going to be recorded? You'll record the installation in the airframe and/or engine logs. Same with removal. Sanding and painting rarely get recorded. Any trips to a prop shop should be recorded, but the reason a fixed pitch is removed from service is as noted above; getting to short, thin, or bent.

    Estimate the total time of the prop to satisfy some bean counter but it's hardly a useful piece of info for the item. After all, the regs state that we need to keep logs on 'appliances and components' also. When's the last time anyone did that? Or was even asked about it?

    Web
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  14. #14

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    If you are going to do that, avoid using "estimated 3000 hours total time." There will come a day, probably before they start doing carbon-14 dating on our data tags, when IAs will be taught to look for total time airframe, engine, and prop.

    I currently insist on total time airframe and engine, and not "estimates". I don't make a living doing annuals. I can't afford it, and am more interested in flying. But I won't sign an aircraft without "total time" stated in the logbook.

    I agree with Web - big difference fixed vs. C/S. But the regulation doesn't differentiate. See dga's post above - it is one of the few things in this business that is crystal clear. You absolutely need total time. You do not need logbooks - but you cannot operate legally without total time.
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  15. #15

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    Quote Originally Posted by bob turner View Post
    If you are going to do that, avoid using "estimated 3000 hours total time." There will come a day, probably before they start doing carbon-14 dating on our data tags, when IAs will be taught to look for total time airframe, engine, and prop.

    I currently insist on total time airframe and engine, and not "estimates". I don't make a living doing annuals. I can't afford it, and am more interested in flying. But I won't sign an aircraft without "total time" stated in the logbook.

    I agree with Web - big difference fixed vs. C/S. But the regulation doesn't differentiate. See dga's post above - it is one of the few things in this business that is crystal clear. You absolutely need total time. You do not need logbooks - but you cannot operate legally without total time.
    Not sure if it is still the case, but I used to buy “new” Hartzell props from one of the local prop shops. They were overhauled props with 0 time in service. It was cheaper for him to buy all the component parts and assemble them in his shop than to buy a complete prop through Hartzell. Since they were all new parts, total time was 0 hours, but no 8130-3 from Hartzell since they didn’t assemble it.

    Lots of airplanes have lost log books, lots of engines have lost log books, lots of props never had log books! I think if we do the best we can with the data we have, we will be OK. Just start a new log and say time carried forward. Make sure ADs are complied with, and if there are any life limited parts replace them!


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  16. #16

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    Agree. 100%.

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