Constant Speed Prop Overhaul?

Is there a time limit a constant speed prop can sit (unused) before it needs an overhaul? Found a prop with only 9 hours on it but it has been sitting on a plane for 10 years un-run/uncirculated.

Depends on the prop. If you can find a service manual or information on that model prop from the factory, that's your best guide.

Dave

McCauley props have a time as well as flight-hours limit for TBO. It is either 6 years or 7 years, I don't quite recall.

I don't believe Hartzell props have a time limit. Someone else may correct me.

I can share two experiences regarding McCauley props that suggest that the time limit should be respected.

First was my Whirl Wind 200RV prop which uses a McCauley hub (or a copy of a McCauley hub). It was spitting grease at 300 hrs. and five years. That apparently was from an incompatibility between the o-rings and the grease. So I had it overhauled. Whirl Wind provided a replacement 0-ring kit using Viton o-rings. The overhaul shop found that the bearings and races were all badly pitted and all internals were replaced.

Second was a McCauley 3-blade prop on a Cessna 182 that had 400 hrs, but that was almost 20 years. So I had it overhauled. The overhaul shop found that the bearings and races were all badly pitted and all internals were replaced.

The MT prop on our RV 10 had a 7year inspection period.

I talked to a MT authorized shop and they said this was based on a couple potential issues------grease seals becoming dry/brittle/shrunken and the wood core of the prop drying out and shrinking enough to cause issues at the hub end.

I was told how to check for the above issues, and luckily things were just fine.

I suggest you talk to the prop manufacture or a shop authorized by the manufacture to do service work.

I had a similar situation with my Hartzell. Very low hours, but OH was long ago. Had Sensenich up on Lancaster PA do an IRAN and reseal. Cost about $1200 iirc, but came back looking like new and gave me a lot of confidence in it.

What is the usual prop overhaul on a 3 blade constant speed? McCauley.

dmat said:

What is the usual prop overhaul on a 3 blade constant speed? McCauley.

Click to expand...

I just had one done in December. Mine was an oil-filled type, not sure that matters. D3A36C435 / 80VEA-0
Two prop shops quoted exactly the same price, $4800 + parts. Came out to be $5600.

Thanks everyone! That helps me a ton!

Check if the prop shop can do an "IRAN" instead of an overhaul-----might be lower cost.

We have recently had introduced a low use inspection for c/s props in UK/Europe. It allows for a lot more practicality to be shown towards the calendar overhaul when not a lot of hours have been flown. It also means no blade strip, re roll and subsequent overhaul damage to the blade.

Most manufacturers have a 6 year overhaul period but if you buy new, the first 2 years storage does not start the clock ticking but it does after that.

Unlike engines, props can't go onto 'extension'. Time is the key.

MT have a low use programme, as do Hartzell. If you have a McCauley, expect corrosion with time, my shop said they were far and away the worst on inspection.

I had a brand new Hartzel prop, wrapped up in the box, from Hartzel. It was stored in it's unopened box in SoCal in may hangar for about 3 years before it was installed. It leaked grease and wouldn't balance. I called Hartzel, they told me to remove it and put it back in the box. They sent me a call tag and it was shipped to some prop shop in AZ (can't remember the name) where it was rebuilt and resealed, Hartzel paid for it. Other than the huge dent the shop put on one blade it work fine.

My -9A was build in 2011 and has 500 hours. I opted to have Stockton Propeller pick it up during the last annual and they did inspection and replace as needed. I honestly just stumbled upon the 72 month recommendation while browsing the prop manual during the annual and thought it was well past time. I think the total cost was about $2000 with new seals, bearings, blades resurfaced and painted. I made all sorts of marks indicating where the hub aligned with the cap, blade orientation etc so I minimized any imbalance after service. Came back after a week and it's smooth as silk. I was not having any issues with the prop and I usually adhere to the "if it ain't broke, don't fix it" mindset but with the prop, when it's broke, it's a real bad day.

David

In Canada we seem to have a mandatory 10 year overhaul cycle :-(
Our brand-new compact-hub Hartzell had been installed on the brand new engine and never run for 10 years. When I called the prop shop they told me the 10 year calendar cycle would be reset to zero if I sent the prop in for a re-seal. Good thing I did as a couple of the seals had dried out and would have had a high probability of leakage.

In talking to the guys on the shop floor, their comments mirrored many of those made previously in this thread. The drying up of seals is an issue, but fades into insignificance when compared to the nastiness that corrosion causes. They showed me a Hartzell hub that was low-time but was being scrapped because of corrosion. They had talked to the owner who divulged his airplane was tied down outside rather than hangared. This seems to be a common cause of props being scrapped.