The International Cessna 170 Association

It was requested in another thread that I report on the MT propeller I have mounted on my O360 powered 170B.
The airplane had a 2 blade MT when I purchased it last July and flew it down from Anchorage to Washington state.
Soon after getting back home, after an epic 3 day journey through Alaska and down the Trench through the Yukon and B.C., I removed the 2 blade and installed a 3 blade MT I had already purchased for a DelAir conversion of my 170A.
DelAir could not produce the kit they had promised for my conversion so I ended up purchasing this already converted B model and selling the A. That left me with a brand new O360 I had built and an still trying to sell, the 3 blade MT prop and several other items I had acquired in anticipation of converting my 170A.
Enough about that - back to the props...
In comparison between the 2 & 3 blade MT: the 2 blade is about 5 mph faster but the 3 is a little better on take off and climb - exactly like John Nielsen at Flight Resources said it would be.
The first thing that is very noticeable is when you apply throttle the propeller responds immediately.
Takes a little getting used to when bumping the throttle to arrest last minute sink on landing meaning it's very easy to add too much power, but very user friendly once you get familiar.
The second thing that really gets your attention is how super smooth it is - even makes the big 4 cylinder Lycoming feel turbine smooth. They say the composite material absorbs the vibration rather than transmit or amplify it like a metal prop can.
Next thing that got my attention was the huge braking effect when you pull the power back substantially - nearly slides you forward in your seat - another user friendly tool for steep approaches once you anticipate it and learn to use it to your advantage. My first landing approach I found myself low far from the runway not expecting this braking effect. I had heard of this but to experience it first hand was amazing.
Then there is the much lighter weight on the nose, no rpm restriction and the fact the MT is happy running at lower rpm. If you're not in a hurry, cruising at 23 mp and 19-21 rpm still gets me 100 - 110 mph at 6.5 to 7.5 gph.
I am sporting 31" Bushwheels so your results may vary...
All the good things I've heard about these props are true. Also true is that they are expensive. That is the only thing I can think of that may be anything but positive to say - but you get what you pay for and these are a top quality product.
If you are trying to achieve the best possible performance from your aircraft I think the composite MT propellers, both the 2 and 3 blade, are an excellent choice.
IMHO

Thanks for the information, as I was interested in knowing the throttle off response during let down knowing there's the difference in weight between metal and composite. Is the propeller operation as smooth when decreasing power as it is when accelerating?

Very smooth in all phases of operation.

Everything Fishdoc said. The governing range is much wider than the Hartzell, which was on the stops and acting as a fixed-pitch prop in the pattern, and pretty much anywhere below low cruise. That made the yellow arc on the tach even more annoying. The MT doesn't lose governing until the power is way back, under 10" MP. Even then it's very responsive to the prop control, as Fishdoc said, allowing you to steepen or stretch a glide dramatically. And while the MT doesn't give the Lycoming that warm O-300 hum, it is extremely smooth at all RPM. I can honestly say the MT has been even more of an improvement than I expected, though to be fair, the Hartzell Trailblazer probably would have been, too. The Hartzell HC-C2YK is an old design.

Hey guys, how does the MT perform in a true power off situation? With well under 10" will it reliably go to full pitch when you pull the prop all the way back? I'm curious because this can make a dramatic difference for power off glide in an emergency.

It goes full flat the instant you pull power to idle. Both the 2 & 3 blade - maybe a little more braking effect with the 3 than the 2 blade but both are quite dramatic as a speed brake.

Installed 3 blade MT four months ago, results are exactly as DaveF & fishdoc state, am very pleased with it, it is very responsive & have learned to be smoother & slower when adding power during departure . At idle the prop has a very different but cool sound as it slaps the air !

fishdoc wrote:It goes full flat the instant you pull power to idle. Both the 2 & 3 blade - maybe a little more braking effect with the 3 than the 2 blade but both are quite dramatic as a speed brake.

Interesting, thanks.
What about glide, have you tried power off with the prop control all the way out to extend the glide?
Chris

Even with the blue knob all the way out the prop goes to full flat at idle throttle setting as I don't have the feathering or reversing option installed like you might find on a turbo-prop.
That is an available option on these propellers though.

I find that pulling the prop control on base or final stretches the glide a lot. As the RPM drops, things get quieter and the airplane accelerates.

Do you still have that engine and prop?

If you mean me, yes.