Automatic Prop

jcknox · #1 01-10-2011, 07:25 PM

Anyone have experience with the Aeromatic Propeller? The benefits of a CP propeller without the weight or complexity.

http://www.aeromatic.com/

jrs14855 · #2 01-11-2011, 03:24 AM

The aeromatics are not suitable for aircraft with the speed range of the RV's. They worked ok on a Stinson or the Swift with 125 hp. Very expensive to buy and maintain.

Vern · #3 01-11-2011, 04:41 AM

Antiques and uncommon now

DEWATSON · #4 01-11-2011, 11:44 AM

If you go Aeromatic, you better buy three............one on the way to the shop, one on the way back from the shop and one to fly until it breaks.

Denase · #5 01-11-2011, 03:26 PM

Antiques, not very reliable, uncommon, sure. But what about an updated Aeromatic? Seems like the premise is good, can it be brought back with new technology? Carbon fibre? Sure seems like a neat idea, suppose all it takes is money.

breister · #6 01-16-2011, 02:05 PM

There have been many attempts at something like this. For a while, the composite gurus were touting that they could cause a prop to twist in such a way as to act like a C/S prop based on propeller load, but further testing determined that the effect was minimal or non-existent.

The trouble with the Aeromatic was that it has all of the complexity of a C/S prop without the utility. If you are going to go to the trouble to put in a pitch-adjusting mechanism, it's much easier and nicer to go full C/S - because then the pilot gets to choose what RPM he wants to let the prop turn at based on flight conditions.

elippse · #7 01-16-2011, 10:24 PM

Quote:

Originally Posted by breister

There have been many attempts at something like this. For a while, the composite gurus were touting that they could cause a prop to twist in such a way as to act like a C/S prop based on propeller load, but further testing determined that the effect was minimal or non-existent.

Really, breister, are you implying that these so-called "almost constant speed" props really weren't? Reassure me that while posting this you're not sitting on your veranda sucking on too many mint juleps.
And here I was giving these people kudos, at least in my mind, for being able to match the compliance of the wood core and the composite laminate and the CM of the airfoil to achieve this change of pitch with load or rpm and now you tell me that they really couldn't? I'm so disappointed that I'm going to have to sign myself into a mental health clinic!
Bummer!

Greg Arehart · #8 01-16-2011, 10:32 PM

Interesting thread. I have a buddy who has one of these still in the box and was going to go pick it up and consider whether it might work on an RV. There is a fellow near here (Kent Tarver - Fallon, NV - has posted here on the forum occasionally) who now owns the rights to these and I have been meaning to get over to talk with him.

Why don't they work on faster airplanes? Can't get enough pitch? Forgive the silly questions, but I don't consider myself very knowledgeable about props.

Cheers,
greg

jcknox · #9 01-17-2011, 02:17 PM

I've read the web site completely and think there to be no reason why it would not. I would be very interested in the details if you happen to go by and ask about it.

N941WR · #10 01-17-2011, 03:03 PM

I have flown behind an early version of this prop on a friend's F24W and it performed really well.

I too looked at one for my rebuild but with so few out there, I elected to stick with Catto as the prop is one place I really don't want to experiment too much.