Hey Folks,
I figured there would be some real knowledge over here on this topic. In Europe nobody knows much use for Cessna 206's other than meat bombing. We are restoring a Cessna U206F that flipped in 2005 and has sat virtually finished outside in long grass until we rescued it this summer. Huge work has been done, but the propeller is now becoming a priority. When the airplane flipped the Hartzell obviously got hit hard, the previous owner had a McCauley D3A32C90/82NC-2 and he hung it on there. No logs or paperwork. This is the way it was when we got it. The prop shop we sent it to sucked their teeth hard, and went through the whole obsolete prop routine. We haven't yet asked them to go any further in opening it up.

My other option is a McCauley D3A34C402/90DFA-10 that I have here spare, I could rebuild it with 401 hub if my blades are good. My question is which route would you go;

a) Rebuild the threaded prop? Is this as big a deal as they make out?
b) Ditch the threaded prop and use the D3A34C402/90DFA-10 with a new hub and Air Plains STC?
c) Buy a Hartzell

Any advice appreciated!

William Flood

As a former Prop Repairman and Chief Inspector, I definitely would not recommend putting any money into the C90. Ferrules
are almost non existent, hard to seal the red oil in, it goes on and on.

The 401 will pull better than the pencil point C90. Find a serviceable hub for your blades and you'll have a modern Backcountry Buster.

Richard

The company I work for operates 4 206’s commercially, and maintain some for coustomers. we went to 401’s and 402’s depending, best prop for a 206 hands down. To much down time with a C90,an AD note will not let you operate with a dyed oil leak and they leak often, they were designed to hold grease, not oil. Plus the parts issue.In my opinion the hartzels don’t pull as hard as a C90, and much less then a 401, just never cared for them on a 206. I believe p ponk has an stc to run the 402 on a f model. It is better, moves the cg forward and stops the common problem of the backing plate rubbing the nose bowl. It looks different if you don’t put the g model extended nose bowls on, but after all it’s a working airplane

Ete wrote:The company I work for operates 4 206’s commercially, and maintain some for coustomers. we went to 401’s and 402’s depending, best prop for a 206 hands down. To much down time with a C90,an AD note will not let you operate with a dyed oil leak and they leak often, they were designed to hold grease, not oil. Plus the parts issue.In my opinion the hartzels don’t pull as hard as a C90, and much less then a 401, just never cared for them on a 206. I believe p ponk has an stc to run the 402 on a f model. It is better, moves the cg forward and stops the common problem of the backing plate rubbing the nose bowl. It looks different if you don’t put the g model extended nose bowls on, but after all it’s a working airplane

This info is awesome. Are you talking about the 3 blade hartzell top prop? I'm prop shopping for my 206 and have a couple hartzell options...

I just want to know what "meat bombing" is. It sounds like something I might like.

PilotMikeTx wrote:I just want to know what "meat bombing" is. It sounds like something I might like.

Hauling skydivers

Really great replies here. Thanks very much to everyone who posted. I don't want to install a prop that will leak, or degrade the performance of the project.

The McCauley D3A34C402/90DFA-10 I have in my hangar was overhauled in 1998 but never turned a blade since. Is corrosion in the hub or blades a flight safety issue? In Europe every other prop I know of that goes to a prop shop for an overhaul gets condemned with corrosion.

I'll do a test fit of the prop to see how much the extended hub shows with the regular U206F cowls and post a picture back here.

That doesn't sound nearly as fun as what I had in mind.

You need to have the prop resealed and new grease. The Aeroshell 5 That lubricates the bearings breaks down after just a few years and starts leaking out the blade seals. You definitely need to have all new O rings installed also. It's not a big deal, should be able to do within 4 hours labor. They will also put fresh lube on your shim/ shim carrier underneath the blade retention ring you see where the blade exits the hub.

The spinner backing plate assembly for the 402 prop is different also than the C90/C401. You can get part numbers off the McCauley application guide on their website. It has a collar that slides up the hub extension and bolts on with Six coarse thread bolts and safetied.

Richard

The Hartzells I have experience with are y shank hub props with club shaped blades, can’t rember the model number. I haven’t spent much time with the later semitar blades, not sure what Hartzell is marketing it as now. The McCaulys did such a good job I quit following Hartzell altogether. Ford/Chevy deal. As far as corrosion goes we don’t have any trouble that way, but it’s extremely dry here and a long ways from the coast.

So here's where we got to with the D3A34C402/90DFA-10 I sent to the prop shop:

"Morning William

Not good news I'm afraid.

Your Propeller is very heavily corroded, the Blades, Hub and most of the Internals are too far gone to use.
If you give Mark a call, he can give you more details.

What do you want us to do with the wooden box and Prop"


Here's where we got to with the D3A32C90/82NC-2 I also sent to the prop shop:

$7850 USD roughly and could be more to overhaul it if we need a ferrule.....



I am getting a price from Centennial Air Parts on OHC McCauley D3A34C401/90DFA-10 as shipping a three blade prop to Europe is only $600 by DHL. Any other idea's?

Very nice work! I love to see how these old Cessna's find new life.

I am doing the same thing with an early model cessna U206A which has the same propeller as yours, only I have it in parts and many things are missing. We are currently overhauling this old beast in Belgium and hope to have it flying by the end of 2019.
Our U206A is a 1965 model and stopped flying in May 1980 after 1400hr TT. It used to belong to Delta Air Transport and then it went to Diest skydive in Belgium as OO-VDC. We have the intention to register her back on the FAA with an N-number because with my licenses it will make things much easier.

Since we are not very far located from each-other maybe we can join forces sourcing parts. I am trying either to source a donor crashed 206 or to order part by part (which may be more expensive but at least it's spread over the whole year).

I already restored a c205 during 2015-2017 and went from SE-EST to N210XL. I am flying that one for fun. It used to be also a skydive plane with lots of cycles on it but if you see it now you would never guess.