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Looks like my A-D wood prop is toast :-(

Neal@F14

Well Known Member
Flew in the rain last weekend, and it eroded a little paint off the leading edges so I decided to remove the prop today to touch up the paint and discovered a 1.5" long crack on the back side of one of the blades near the root/hub.

The crack is the junction between two of the wood laminate layers. The two round plugged holes are apparently where balance weights were pressed in when the prop was manufactured. As you can see, there's another crack emanating from the same plugged hole about 1/2 inch back towards the hub.

Total time on this prop is 356 hours since new.

Prop_Crack.jpg.JPG


Well, I was wanting to try one of the new Sensenich ground adjustable props but not yet budget-equipped to shell out the 4 AMUs.

Looks like my Oshkosh trip may have to be cancelled... (maybe not, new prop is on the way)

Also one of the other RV owners on my field has a 68x74 Performance Propellers wood prop on his 160hp RV3 that he said he'd loan me, but I don't want him to take his plane apart just for that.
 
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Probably means a wood prop from Aymar-DeMuth.

Yep "A-D" stands for Aymar-Demuth, who apparently was one of the premier wooden prop makers for RVs, Mustang IIs, Thorpes, and other experimentals, before Catto dethroned them.

Both of the guys who ran the company and made these props have now both passed away, and the company is defunct.

Their props are made with about 5 or 6 thick layers of wood (planks) laminated together, and there unfortunately is a bit of history of some them losing blades or large pieces of blades in flight, in spectacular ways. There are also plenty of their props have been in service for years/decades without problems too.

I had several knowledgeable folks look over my prop this weekend and they all concur that the crack is a result of the wood drying out over its 11 years since manufacture, compounded by the fact that a couple holes were drilled into the hub area to insert balance weights, and this likely created a stress zone in the wood. Anyway, what I have now is a 68" long wooden wall ornament. Even if by some far-fetched method, the crack could be repaired by injecting epoxy into it or something, I would never trust flying behind it again.

To "PropMan" Frank: Thanks for the generous offer of a loaner prop. I'm trying to see if I can make my financial situation work out to get a Sensenich composite ground adjustable prop (painfully expensive at the moment) but if that falls thru, you'll likely be getting a call from me. Your props are absolutely beautiful, and I can see that with eleventy-bazillion thin layers of wood laminated and sealed together like that, that there's no way they'll fail in the manner as my A-D prop did.

I know that everybody else here recommends Catto, and if I had a lot of spare time to wait around for delivery, that might be an option too, but the prospect of having stainless steel leading edges, and ground adjustability of the pitch is very alluring on the new Sensenich prop. The WhirlWind ground adjustable prop also looks good, for considerably less money than the Sensenich, but they way you have to manually set the blade pitch with a protractor and trial-and-error just looks like a royal pain, and Sensenich's machined pins method makes childs play of adjusting pitch.
 
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I really enjoyed my Aymar Demuth prop. Only reason I changed was for nickel edges. My A-D prop has been fully restored and match-painted for my airplane.

Neal, sorry to hear your's cracked.
 
Well, I just pulled the trigger on a new prop. Don from Sensenich was able to arrange for a white one with red tips to get shipped here by this Friday. I know it won't be the same shade of white and red as the rest of my plane, but it'll look better than the normal black blades with white tips.

My poor credit card is screaming in agony and I have that unpleasant feeling in the pit of my stomach that always accompanies making very large purchases.

Oh well... buy once, cry once, eh?

I guess I must recite my two rules about money and aviation...

1) Never ever try to cost-justify owning and flying a small aircraft. It's impossible.
2) Never ever add up all the money you've spent on owning and flying small aircraft. You don't want to know.
 
I feel your pain, Neal!

Two weeks ago today, I called Van's and ordered my Hartzell BA prop. I put over half deposit on it, and they told me 2-4 weeks lead time. Last monday, I got a call saying Hartzell was ready to ship my prop and could I please remit the balance due :)

Prop arrived on thursday. I'm not quite ready for it yet, but it sure is pretty! My bank account is still mad at me though...

Well, I just pulled the trigger on a new prop. Don from Sensenich was able to arrange for a white one with red tips to get shipped here by this Friday. I know it won't be the same shade of white and red as the rest of my plane, but it'll look better than the normal black blades with white tips.

My poor credit card is screaming in agony and I have that unpleasant feeling in the pit of my stomach that always accompanies making very large purchases.

Oh well... buy once, cry once, eh?

I guess I must recite my two rules about money and aviation...

1) Never ever try to cost-justify owning and flying a small aircraft. It's impossible.
2) Never ever add up all the money you've spent on owning and flying small aircraft. You don't want to know.
 
Sorry to hear you went to the dark side;), but I look forward to a report on performance.


Well, I just pulled the trigger on a new prop. Don from Sensenich was able to arrange for a white one with red tips to get shipped here by this Friday. I know it won't be the same shade of white and red as the rest of my plane, but it'll look better than the normal black blades with white tips.

My poor credit card is screaming in agony and I have that unpleasant feeling in the pit of my stomach that always accompanies making very large purchases.

Oh well... buy once, cry once, eh?

I guess I must recite my two rules about money and aviation...

1) Never ever try to cost-justify owning and flying a small aircraft. It's impossible.
2) Never ever add up all the money you've spent on owning and flying small aircraft. You don't want to know.
 
Sorry to hear you went to the dark side;)

Every month when I make that big credit card payment I'm going to be thinking that for less than half the total cost I could've had one of your beautiful new wood props that would probably have been just perfectly fine for over 90% of my flying :eek:

But I will definitely be reporting on the performance of this newfangled hi-tech prop as it compared to my old wood prop.
 
My poor credit card is screaming in agony and I have that unpleasant feeling in the pit of my stomach that always accompanies making very large purchases.

Oh well... buy once, cry once, eh?

I guess I must recite my two rules about money and aviation...

1) Never ever try to cost-justify owning and flying a small aircraft. It's impossible.
2) Never ever add up all the money you've spent on owning and flying small aircraft. You don't want to know.

Who are you and will you please stop reading my mind?
 
Off topic

I was installing a repaired ($11K) Lycoming last week when one of my clients friends remarked "oh the joy of spending money on an airplane, isn't that what life is about?:rolleyes:
 
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