Propeller Overhauls
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- เผยแพร่เมื่อ 25 ส.ค. 2024
- Most props have a Time Between Overhaul (TBO) of 2000-2400 hours and 60-72 months, whichever comes first. You’d have to average more than 400 hours/year for the hours to come first. For most of us, the months come first. For a typical GA airplane that flies 100 hours a year, the prop may come due for overhaul in less than 500 hours. Do we have to overhaul our props that often? Does it even make sense to do that? Mike Busch deconstructs these TBOs and offers specific money- and downtime-saving recommendations. Savvy Aviation offers Professional Maintenance Services to owners of General Aviation aircraft, such as: SavvyMx (Professional Maintenance Management), SavvyQA (Expert Consulting), SavvyPrebuy, SavvyAnalysis (Engine Data Analysis) and Breakdown Assistance. Savvy also publishes a monthly newsletter with lots of interesting information for the general aviation enthusiast; subscribe to it at www.savvyaviat.... For more information, visit us at savvyaviation.com. This webinar was hosted by the Experimental Aircraft Association (EAA).
Former McCauley factory trainer (who also speaks Hartzell) chiming in. A few notes:
The prop is also a centrifuge. The spinning separates the lubricant from from the clay base. We like to pump grease in until the grease exiting looks like the grease going in. That also helps purge any trapped moisture. Modern Hartzells use Aeroshell 6 unless otherwise placarded or noted in the records.
As far as blade position while parked, we don’t like flat spots where water sits. One blade up will let water get in under the shims where the paint is worn off from constant movement. ANY corrosion in the blade retention area is cause for rejecting the hub.
During a reseal, ask for a widths & thickness check of the blades. That’s fast & easy. I’d also ask for a similar check on a fixed pitch. If blade track is fine (A&P checkable on-wing), a face alignment probably isn’t necessary. If lots of material has been removed while dressing nicks over the years, you may not be getting book performance. Personal experience: I’ve seen sagging tachometers that went undetected because the prop was whittled down enough that the engine was showing a false acceptable static RPM. An optical tach on the glare shield revealed the discrepancy (engine was being severely over-sped).
McCauley now “forbids” polishing props due to corrosion issues. If you are in a low-corrosion area, it’s probably not an issue if you are careful not to remove too much metal. I’d personally clear coat it if running a polished prop, but that paint does give erosion protection, too…
McCauley says any quality paint is fine.
McCauley allows cycling the prop repeatedly to “wash” the o-rings if you have a leak, and continue operation up to 10 hours to see if the leak will stop (if it’s threaded I’d be VERY cautious unless you KNOW exactly where the oil is coming from).
I have seen hangared props 50 miles from the Gulf of Mexico eaten up by corrosion and scrapped at first overhaul due to lack of paint & care. I particularly hate stickers.
Easy answer: If you have a 2-digit model number, it’s a threaded hub and should be converted to oil with dye additive. If it’s a 3-digit model (200/300 series 2-blade, 400/500 series 3-blade) it’s threadless.
OWNERS & A&Ps: Download the latest owners manuals from the manufacturer’s website. They are free! They will give you guidance on terminology definitions and what owners & mechanics can do in the field. Hartzell changed some installation torque specs a few years back and if you use the old numbers you might damage a propeller. Don’t be lazy and just use the data in the logbook without checking its currency!
Sounds like you know those fan spinny things well. Thank you for the info..
Savvy, that's the Best description of these podcasts! Thank you for both this propeller information and the LOP, "Lean of Peak", Best Cruise, 65% power Information!
Thanks for putting this content on TH-cam.
Glad you enjoy it!
Perfect timing! Just looking into a prop overhaul. I’ll send a link for this video to the owner.
Are you on the East or West coast are you going to share you experience?
"Where corrosion is outlawed by local statute" LOLOL
Great webinar. I’ve watch ever one multiple times.
Agree totally! My plane is in a climate and humidity controlled hangar. Humidity 30% or less and Rate of evaporation exceeding .3 lb/ft/hr. Tampa was .04 lbFtHr on a good day.
I also use cowl plugs to allow temp to cool slowly while temp and humidity stabilize after putting away for the day.
Gracias por compartir su conocimiento con nosotros.
Saludos desde la República del Paraguay.
just talking prop overhaul yesterday. This clears up alot.
Thankyou for the year of information and technology covering essential components of general aviation planes.
Merry Christmas and happy New year.
🎄🎆🛩️🔍
Happy holidays!
SO bummed pre registered
I really wanted to make the live feed , questions experiences with Hartzell How they killed the earlier Aztecs/ Apache's and your "opinion" reguarding their 100hr AD with low time props, adding carb cleaner to an open wound, bought 2 O/H extras with logs never installed, "life" hit me hard, Now the New 1's will hit the calendar time next Mo.! Thanks Mike & AOPA for ALL that you do
If your insurance company says you have to comply with a certain SB, that is, for all practical purposes, mandatory, too!
Funny that Mike literally mentioned my home base at KTPF Peter OKnight))))
F
What about wood made propellers?
can scara robotic arm be used to overhaul propeller ?
So if not an A&P, then who (what certifications) are required for working on (swapping, installing, repairing) instruments?
Any A&P or a mechanic in training working under the supervision of an A&P can swap out an instrument or install a new instrument but neither of these two people could actually break into the instrument to do an inspection or repair. As Mike said instruments need to go to a repair station for any service or repair.
Nicks are removed with a restraining order. Any Nick over 6' or 300 lbs should be considered dangerous.
lol