I saw a prop recently on a 1946 Bellanca Cruisemaster that looked strange. I looked it up.

It's automatically adjustable using counterweights, no pilot input required!

http://www.aeromatic.com/

They told me it's certified for a 170, but I'd need a field approval for my 172. I could sure use the better climb and faster cruise!

Does anyone have any experience with these? Or, unsubstantiated opinions?

I've been around them a bit with Crusairs......they're awesome when set up right. I find that the people that criticize them are people that have no experience or wont take the time to set them up right. If you don't have patience to figure out how they work and how to set them, they're a huge PIA.... once set, they'll amaze you with the performance. That being said, they're not completely fool proof, and take a bit of maintenance.
I've never been around one on a 170, although I've seen a few..and one guy hated his, the others loved theirs for what they were. They all agreed that if you were figuring on it being as good as a constant speed, you'd be disappointed.
They have some quirks, and some drawbacks, but I know on the Franklin powered Cruisair, they work great when set up right.
John

A few are on 140's. It is actually a constant speed prop, kind of. You set it up at a certain RPM, say 2400 and it has a tendency to stay there. So if you set it up for 2500 RPM for good T/O performance, then it wants to cruise at 2500 RPM. Set it up for 2400 RPM cruise and you lose a little T/O performance. You end up with something roughly between an adjustable, constant speed prop and a fixed prop when they are set up right.
I haven't done one, but my understanding is that it doesn't take a rocket scientist to set one up.

My understanding of the prop is that they work well when there is a good difference between cruse and climb, that is why they work so well on a cruse air, they do not work as well when there is a small difference, i.e. stinson 85 climb and 115 cruse. That may be a problem on a 172 as well.

These are now made by a guy named Tarver, he has the PMA and stc's

kevbert wrote:I saw a prop recently on a 1946 Bellanca Cruisemaster that looked strange. I looked it up.

It's automatically adjustable using counterweights, no pilot input required!

http://www.aeromatic.com/

They told me it's certified for a 170, but I'd need a field approval for my 172. I could sure use the better climb and faster cruise!

Does anyone have any experience with these? Or, unsubstantiated opinions?

YES~go to Tarver Propellor http://www.aeromatic.com/sb2000_001.htm
they (Kent Tarver) have the Type Certificate and repair station for these.