F

fly017

I'm New Here
Does anyone know how to get ahold of Aymar DeMuth? I purchased an RV-4 several months ago with one of these props on it and it appears there are some cracks forming on one of the blades. I would like to send it back to the manufacture to be inspected. Is the company still in business? Any other suggestions would be appreciated. Thanks!
 
Be very carefull. I purchased a RV6a a couple months ago with an Aymar Demuth on it and it came apart this last weekend. Chucked a big wedge piece out of one blade and split all the way to the hub. WAY more excitement than my wife or I needed.
 
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I had one shed a blade

I shed a blade one day in flight. I made the airport, search the archives for Aymar-Demuth and I am sure you will find other similar stories. I think it has something to do with the way they do their leading edges or airfoil thickness. I loved the prop, until it came apart.​
 
Mike was in Maryland the last time I talked to him.

410-461-4329

Its been several years ago.

Be prepared to talk for 'a-while' when you call him.

If he has moved to South carolina, please post the new addy and phone.

I have one of his props and its been fine. I have refinished it a couple of times.
 
Prop Failure

I read a few reports on the Demuth props failing...not good. I was hoping this would not be the case. I may have to look for a different brand instead of having this one fixed.

I appreciate all your comments and help with the e-mail address. Any other info on these props would be greatly appreciated.
 
664781 said:
Here's his email address. He is in South Carolina now.
'[email protected]'
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Aymar has long since departed us. His nephew Mike runs the show now. He advertises in back of EAA's Sport Aviation for current address and phone number. I have never been able to contact him by email. Yeah, Mike will talk to you.

I have one of his props and really like it for combination of climb & cruise. Might change my mind if a blade departed however. I bought it new from him and am impressed with workmanship. I'm changing over to a Catto 3 blade just because they look so pretty sitting on the ramp.....:)

_________________________________
Deal Fair
RV-4
George West, TX
 
Yeah, but also....

dealfair said:
.... I'm changing over to a Catto 3 blade just because they look so pretty sitting on the ramp.....:)

_________________________________
Deal Fair
RV-4
George West, TX
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....because they beat Van's numbers in cruise!!

Blue skies,
 
I replaced my A-D with Catto

caryr said:
Brent, what did you replace the A-D prop with??
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Originally a Catto two blade, and then a Catto three blade. Both great props. I have made other posts about this if you search my postings.
 
Brent,

Do you like the 3-blade obver the 2-blade? Is it worth the extra cost and did you see any change in performance?

Thanks for your help!
 
Catto Performance

I think my 3 blade might be a knot or two slower at top speed, but it is smoother and climbs better. The operative word here is "think." That holds with the theory that an extra blade has more drag, but can be optimized at lower tip speeds because it is smaller diameter. Check my other posts on the subject. I think I wrote them up in detail there. To find my other posts go to advanced search and search on N999BT for user name and Catto as a key word. You will find them.

The highest speed run I have done was with the Catto 2 blade on a really cold day (1 deg F) at 5500 ft pressure altitude, 182 Kt IAS, 2820 RPM. This is equivelent to 196 Kt TAS. I have not tried the same thing with the 3 blade, and also since then I have added leading edge tape to the 3 blade for erosion reasons, so I have probably given up a couple knots. I fly in the clouds a fair amount and that is hard on props.
 
My AD came apart too

A couple years after I sold my 4, the AD prop came apart. About an inch of trailing edge of one blade split off, causing severe vibration.

If any propeller, wood or otherwise, shows any signs of abnormality, my advise would to be to ground it and get it inspected. Props that come apart are no fun at all.
 
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Mine has been working great. but...

I changed to a new AD prop when my Props, Inc prop came loose in flight. At the time, people were recommending them like is now happening with the Catto props. Sure has been a great prop with a better climb and better cruise than my previous prop. However, others stories about AD prop problems is starting to concern me.
 
Bill Wightman said:
A couple years after I sold my 4, the AD prop came apart. About an inch of trailing edge of one blade split off, causing severe vibration.

If any propeller, wood or otherwise, shows any signs of abnormality, my advise would to be to ground it and get it inspected. Props that come apart are no fun at all.
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Agree. I recently replaced my A/D prop with another A/D prop. The original prop had a clear finish, and started showing dark streaks along the grain on one blade. I sanded down and refinished the prop under the assumption that the streaks were where moisture had penetrated the finish and that a sand and refinish job would take care of it.

Unfortunately, the dark streaks returned and the new finish started cracking along the streaks, telling me that there was a crack of sorts that was "working". This made me very uncomfortable, so I spent the bucks to replace the prop with a new A/D prop, but this one has a composite sheath.

I wonder how many failed props (Aymar/Demuth or otherwise) failed after exhibiting signs that something wasn't exactly right with the prop. I've read several tales from the canard folks where they knowingly flew with suspect props which subsequently failed. I'd bet this has happened on RV's too...
 
failure hours report please

Hello, I'm concerned after reading this post.... Can you guys detail the hour mark or time in service that the AD prop came apart? I just bought a -3 with an AD prop and I'm not getting the warm and fuzzy after reading all these reports..... Anybody?
Best
Brian Wallis
 
brianwallis said:
Hello, I'm concerned after reading this post.... Can you guys detail the hour mark or time in service that the AD prop came apart? I just bought a -3 with an AD prop and I'm not getting the warm and fuzzy after reading all these reports..... Anybody?
Best
Brian Wallis
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Brian,

Mine went about 650 hours and 8.5 years before I replaced it. No telling if it was 10 hours or 10 years from becoming a real problem. Whatever the risk was, I wasn't willing to accept it.
 
FWIW

My buddy splintered his Sterba with a prop strike and went with a beautiful 2 blade Catto and picked up 7 MPH at 2740 RPM. The Catto is redlined at 3200 RPM and its looks are gorgeous and so smooth in flight. The -4 went 199 MPH at 6000' and he'd forgotten to lean, so he probably left some RPM/MPH on the table.

Blue skies,
 
AD with composite overlay?

Anybody flying an Amar Demuth with the composite overlay?

Looking at my new Sterba and the old A/D next to each other, there are noticeable differences. The Sterba is a much "beefer" prop with narrower tips. The A/D has a much thinner profile and a wider tip.

I don't know if the thinner profile contributed to the prop splitting but I wonder if anyone running a composite overlaid prop have had any failures. . .especially with an A/D composite wrapped prop?
 
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