When I was prop shopping these are the things that sent me the MT way for my 185.

My 2 blade had time expired and was due for overhaul. I wanted a 3 blade to reduce noise in a built up area I operate, so the choice was Hartzell, Mac or MT. Price was VERY similar for all three by the time you export them down under, in fact the Hartzell was dearer.

The MT is already STC'd for the IO550 if I want to ever consider repowering
As a 135 operator I am obliged to overhaul on calendar time, and I think the MT will prove more cost effective over time in this respect.
The Mac is too noisy IMO, and the Hartzell with their history of AD's didn't inspire me.
The MT is great for noise abatement and still performs VERY well with the rpm wound back a bit on take-off
Weight reduction was a bonus but not a primary consideration for my operations

After my first take-off from home my neighbour came running over asking what I had done to my plane 'cause whatever it was made a huge difference in noise signature

So far I have been very impressed with both the MT and Flight Resource USA

Have a 3blade mt prop plus spinner for sale for lycoming 4 cylinder 200hrs as new 9000.00 . Went back to a p235 84 43 Mac. Pm me for pictures or model no . Was on a 0-375 aero sport

I put one on my O360 powered MX7 about 3 years ago. Flight Resource recommended a 2 blade. Considering my aft CG issues and the weight reduction up front with that prop I opted for a 3 blade. The 3 blade MT was still lighter than the 2 blade Hartzell but only by a few pounds. I know, it's weird to not want to get rid of all the weight you can but if the result would put me out the aft end of the envelope every time I piled my camping gear in the back it didn't make sense.

The pull test that FR did with this prop vs. the 2 blade on the O360 showed the 3 blade pulled harder. I've talked with other operators with the O360/2 blade combo that have been very happy with performance. I expected more than I actually got. OK, maybe I was expecting to need to wear a neck brace to avoid whiplash on takeoff. Initial acceleration improved. Climb rate was not noticeably affected. I don't feel the braking effect others claim when power is reduced. As others have noted, the MT shines at lower rpm cruise. I roll it back to 1900 rpm and 21" mp and get 105 mph at 6.5 gph with 31" ABW's. Nice and quiet.

I discussed MT props with Carbon Cub folks. They had issues with them and several other composit props. The issues turned out to be the engine mods. 10 to 1 Pistons combined with electronic ignition produced an impressive power stroke. The lack of weight in the composit props reduces the flywheel effect so there was a constant pounding on the blades. The result was cracking, and in one case separation, of blades in a very short period of time. I'm not dissing composit props, it's just something to consider if you run a hopped up four banger and you're shopping new props. CC folks said they fixed the problem by removing the high compression pistons.

If I was to do it again I would stick with the FR 2 blade recommendation and carry less camping gear or move my battery to the firewall. I'm still happy as hell that I don't have to deal with the Hartzell folks anymore.

AK-HUNT wrote:To the guys with MT on 180/185,
1. was the approach/landing noticeably better with the weight off the nose? Speed/deck angle, etc? Other?
2. Do u believe it pulls harder than a Mac or nearly same or less? (I think I read a report from Renna last yr but refresh me)

I'm glad we at have good options to mull over!
Thx
Kevin

The weight off the nose can be huge or it can be imperceptible, it depends on a couple more factors like what prop it's replacing and where the empty cg already is. As you already know, making a C180/185 lighter always makes it more nose heavy, and since nose heavy is bad anything you do to combat that is good. The guys that notice this the most will be the ones running the two blade, but it is not enough prop for the bigger engines. If you want a real good way to get a 'real world' assessment of the change in flight characteristics that may prove more tangible to you, look at it this way; A 3 blade MT equipped C185 is going to have the feel of a C66 (two blade) equipped airplane with the tug boat pull of a C401. It is extremely close in weight to the 2 blade mac while being extremely close to the 3 blade in performance.

For ME to compare 'pull' gets a little more complicated. The reason for that is because I judge how a prop performs based solely on how I intend to use it, and that is very different (how it's judged) than by what I see other folks doing…

Allow me to explain..

Pull / Thrust tests with a pull scale….
I'm not sure where this became the industry standard by which prop performance is measured, but somewhere along the way someone decided this was a good barometer, and I think that person was charismatic enough to get all the rest lined up behind him…

Let me get this right… we're going to tie the plane to a scale which is tied to a truck, pour the coals to it, and then pick the prop that pulls the hardest… Hmmm I wonder if that's a decent way to set our mixture too? after all every propellor ever made performs differently at varying DA's and no two props make those changes on the same scale. So my suggestion to anyone who is going to use the strain gauge to select a prop would be to make darn sure you're doing that pull test at a DA reasonably close to what most of your most critical ops are going to be at.
Kevin Quinn, Steve Knopp, and myself all did the exact same pull tests with really good scale. We all came up with different numbers. Quite a bit different actually. Why? because they were all at different DA's To the best of my knowledge, Steve recognizes this and at least tests does all of his testing at the same DA, but even that only tells you what each prop is doing at that DA (I believe he shoots for sea level) and not which is going to take off best at Mile high…

The next issue I take with the Pull test is that I have never locked my brakes, pulled take off power and then launched in a backcountry environment. I simply can't afford to do that to my props, and I simply won't treat my equipment that way. A contest on pavement, maybe, on a gravel bar, negative. The reason this piece is so important is because the MT simply responds as quick as you move the button. From my strip the 401 spanked the MT in tied down pull, but between the spool up response and the weight off the nose, the MT breaks ground sooner every time.

You can take all that with a grain of salt, It's just my observation. If I personally built up another 180/185 tomorrow would I use another? You bet, the only other prop I'd consider would be a full meat C66 in 88" length, but good luck finding one of those. As far as using it on a 135 airplane in your ops? I dunno, that would be something for you to decide, I know nothing of that arena, but good luck with it.

Take care, Rob

Rob makes an excellent point regarding static pull tests.....they are indeed pretty useless.

Another reason is that what is really important in a prop's performance is how it functions during acceleration and other changing circumstances. There is NOTHING static about the blade aerodynamics of a constant speed propeller as the airplane accelerates on takeoff, or enters a climb, etc. Those are very dynamic evolutions, and how the prop performs three seconds into the accel is perhaps more important than how it pulls from the gift go.

The MT props I've flown pull hard from the start, and they keep on pulling throughout the takeoff.

Some props will pull hard static, but hit the wall halfway or three quarter of the way through the run.

MTV

Mr. Ed wrote:I discussed MT props with Carbon Cub folks. They had issues with them and several other composit props. The issues turned out to be the engine mods. 10 to 1 Pistons combined with electronic ignition produced an impressive power stroke. The lack of weight in the composit props reduces the flywheel effect so there was a constant pounding on the blades. The result was cracking, and in one case separation, of blades in a very short period of time. I'm not dissing composit props, it's just something to consider if you run a hopped up four banger and you're shopping new props. CC folks said they fixed the problem by removing the high compression pistons.

Are you sure CC was talking about MT props? Most of the Carbon Cubs I've seen were equipped with composite props made by another manufacturer, not MT. I've never heard of an MT prop failing in the manner which you describe....but?

MTV

mtv wrote:

Mr. Ed wrote:I discussed MT props with Carbon Cub folks. They had issues with them and several other composit props. The issues turned out to be the engine mods. 10 to 1 Pistons combined with electronic ignition produced an impressive power stroke. The lack of weight in the composit props reduces the flywheel effect so there was a constant pounding on the blades. The result was cracking, and in one case separation, of blades in a very short period of time. I'm not dissing composit props, it's just something to consider if you run a hopped up four banger and you're shopping new props. CC folks said they fixed the problem by removing the high compression pistons.

Are you sure CC was talking about MT props? Most of the Carbon Cubs I've seen were equipped with composite props made by another manufacturer, not MT. I've never heard of an MT prop failing in the manner which you describe....but?

MTV

I was watching this discussion with limited interest until reading this last post. What Mr. Ed previously posted seems a bit questionable to me also regarding MT. Maybe another manufacturer is at issue. Nevertheless, here is my experience.

I put a constant speed MT 3 blade prop on my first Pitts and currently have the same on the Pitts I fly right now. Reasons are the overall reduced weight but more important the reduction in blade weight and the resulting reduction in polar moment of inertia (PMI) exerted on the crank shaft. The engine, AEIO-540, 260 HP turning 2700 rpm. This reduction in the PMI saves the crank from snapping in two and the propeller from departing the aircraft when I'm doing gyroscopic maneuvers or tumbles. Sean Tucker has a nifty video of a S-2B he was flying loosing the two blade Hartzell aluminum constant speed prop following some torquing maneuvers. Now this really doesn't have much to do with backcountry flying except, we're talking about the attributes of MT propellers here. I flex the hell out of the blades to put it mildly. I don't fly airshow's but I do all the maneuvers you see in them. "Flywheel effect and constant pounding" causing blade cracking? The blades are made of spruce, are flexible, extremely effective at reducing vibration, are fiberglass covered with a stainless erosion shield leading edge. Out of the box they are extremely well balanced. Not all composite props get carbon fiber blades. The equivalent carbon Hartzell Claw for the Pitts runs 54K. Not even an option.

Would I run a MT on my C180? The reduction in vibration and reduced stress on the engine, bearings, etc. would be beneficial. They pull hard and accelerate well but in my experience I lost a bit of top speed with the Pitts. Apples and oranges I know, and we're talking three blades here. The drag between the two birds is a world apart. I have an 88" Mac that came on the 180 when I bought it. It pulls pretty good and I'm not sure the MT would do much better. One thing that would have me staying with the Mac, hand propping a three blade scares the hell out of me. Call me a wuss but it's not something you'll ever see me try. Now if we go down the road of a MT two blade, I'd reconsider.

If you have your heart set on a MT, buy it. They're great propellers.

Rich

A1Skinner wrote:I've never flown behind one, but regarding the price- I was quoted 12.5k for an 88" mac w/spinner and 17k for an MT. That's after conversion to CAD funds. For my pocket book it's more then enough to discourage me from purchasing one, regardless of how good it is.

When I was prop shopping, I was quoted $8100-ish for an 88" C203 Mac (including spinner) vs $12950 for the MT (USD of course). So a 60% premium over the McCauley. My heart was willing but my pocketbook was weak.

hotrod180 wrote:

A1Skinner wrote:I've never flown behind one, but regarding the price- I was quoted 12.5k for an 88" mac w/spinner and 17k for an MT. That's after conversion to CAD funds. For my pocket book it's more then enough to discourage me from purchasing one, regardless of how good it is.

When I was prop shopping, I was quoted $8100-ish for an 88" C203 Mac (including spinner) vs $12950 for the MT (USD of course). So a 60% premium over the McCauley. My heart was willing but my pocketbook was weak.

Convert that to Canadian and it's about the same as I said...

One positive aspect of the MT prop that no one has really touched on is the long term usability of the blades.

At every overhaul, a metal prop has its blades dressed out and re-balanced. The only way to do this is by removing material from the blades (ie: filing them down). After a few overhauls, the blades may be out of limits and a new set of blades will be required. Of course, this depends on how rough the operator is on the propeller; look at seaplane ops for a good example of blade erosion.

However, because the MT is a composite prop, dressing out the blades involves adding material to bring each back to factory new size and shape. The result is that after every overhaul, you are getting blades that match factory-new specs. Short of catastrophic damage, you will never need to buy new blades for an MT prop.

For most private flyers, this may not matter if you don't put a lot of hours on your prop, but I could see a commercial operator getting a benefit out of this.

Chris

Im just relaying what I discussed with the CC folks. Go have the composit prop discussion next time you see them at at a show/fly-in. I also talked to the original owner of the Grizzly Cub. His engine distroyed the MT in very short order. The MT folks worked with him and they did a bunch of testing to find a blade that would work. I'm not trying to throw mud on MT. I own one and the customer service is cosmic. I haven't had any problems with mine. Take the info, or not, your choice.

hotrod180 wrote:

A1Skinner wrote:I've never flown behind one, but regarding the price- I was quoted 12.5k for an 88" mac w/spinner and 17k for an MT. That's after conversion to CAD funds. For my pocket book it's more then enough to discourage me from purchasing one, regardless of how good it is.

When I was prop shopping, I was quoted $8100-ish for an 88" C203 Mac (including spinner) vs $12950 for the MT (USD of course). So a 60% premium over the McCauley. My heart was willing but my pocketbook was weak.

Considering the MT is German made and given the Euro is now 78% of what it was in 2014, that 60% premium should now have shrunk to about 25%...

mtv wrote:

Mr. Ed wrote:I discussed MT props with Carbon Cub folks. They had issues with them and several other composit props. The issues turned out to be the engine mods. 10 to 1 Pistons combined with electronic ignition produced an impressive power stroke. The lack of weight in the composit props reduces the flywheel effect so there was a constant pounding on the blades. The result was cracking, and in one case separation, of blades in a very short period of time. I'm not dissing composit props, it's just something to consider if you run a hopped up four banger and you're shopping new props. CC folks said they fixed the problem by removing the high compression pistons.

Are you sure CC was talking about MT props? Most of the Carbon Cubs I've seen were equipped with composite props made by another manufacturer, not MT. I've never heard of an MT prop failing in the manner which you describe....but?

MTV

I just got a 3 bladed MT, in talking with the folks in Florida, they begged me not to put it on a 360 as it was not made for the pulses!!
Would work on a 0-320, and the 180hp Sub, but not the 0-360!

Re: post above... Is that just the 360/ 3 blade combo for some
Reason? Obviously you see a lot of 3 Bladers on 180/185's and on RV-10's, and lots of four Bladers going on SR-22's and malibus, etc, etc,. Pretty sure there is an O-360 Powered C-170 out there with a 3 blade MT on it too. I'm just not following why you were advised not to do this??

Hoeschen wrote:Re: post above... Is that just the 360/ 3 blade combo for some
Reason? Obviously you see a lot of 3 Bladers on 180/185's and on RV-10's, and lots of four Bladers going on SR-22's and malibus, etc, etc,. Pretty sure there is an O-360 Powered C-170 out there with a 3 blade MT on it too. I'm just not following why you were advised not to do this??

I understand it is just this style model prop, others might work. This one is an electric CS.

Could John from Flight Resource respond to this?
I'm getting ready to hang a 3 blade MT on my O360.
Surly whatever issues there may have been have been worked out and corrected.

I have seen several 3-blade MT props on O-360 engines. One belongs to a friend of mine who drives a Husky back east. No problems that I am aware of on his end.

Here is the link for the O-360 converted Cessna 170A.
http://www.flight-resource.com/Datasheets/Cessna170-172-175-3Blade.pdf

Zzz wrote:Squash says above that there is no braking effect as opposed to the Black Mac, but perhaps what he meant was that it's not as pronounced, because compared to an aluminum prop, there is definitely an instant response in thrust and airspeed. It's not a brake per se, but there is much less rotational inertia so it slows quickly and it feels like an airbrake. It's something you get used to in your approaches.

I'm not talking about the dynamic change in thrust when you pull off the power. I'm talking about the stabilized power off glide and the amount of drag that is created by the idling propeller. With the 88" Black Mac, the plane comes out of the sky with a glide ratio worse than a super cub. The MT does not produce as much drag and I feel safer crossing water knowing that I can now glide farther with an engine out than I could with the Mac.

I attribute this difference to the change in the low pitch stop (2850 max rpm in the Mac versus 2700 max rpm in the MT) as well as a likely difference in the flat plate drag given the more aerodynamic shape of the blades and the smaller size of the MT prop.

M6RV6 wrote:

mtv wrote:

Mr. Ed wrote:I discussed MT props with Carbon Cub folks. They had issues with them and several other composit props. The issues turned out to be the engine mods. 10 to 1 Pistons combined with electronic ignition produced an impressive power stroke. The lack of weight in the composit props reduces the flywheel effect so there was a constant pounding on the blades. The result was cracking, and in one case separation, of blades in a very short period of time. I'm not dissing composit props, it's just something to consider if you run a hopped up four banger and you're shopping new props. CC folks said they fixed the problem by removing the high compression pistons.

Are you sure CC was talking about MT props? Most of the Carbon Cubs I've seen were equipped with composite props made by another manufacturer, not MT. I've never heard of an MT prop failing in the manner which you describe....but?

MTV

I just got a 3 bladed MT, in talking with the folks in Florida, they begged me not to put it on a 360 as it was not made for the pulses!!
Would work on a 0-320, and the 180hp Sub, but not the 0-360!

Interesting to hear as the IO-360/MT combination is a common choice for many acro aircraft. Giles, One Design, Lazer, S1-T, Eagle, etc.. I will be sending mine in for seal work and will ask the prop shop in Boise what their opinion is.

Rich

[/quote]
I just got a 3 bladed MT, in talking with the folks in Florida, they begged me not to put it on a 360 as it was not made for the pulses!!
Would work on a 0-320, and the 180hp Sub, but not the 0-360![/quote]

Interesting to hear as the IO-360/MT combination is a common choice for many acro aircraft. Giles, One Design, Lazer, S1-T, Eagle, etc.. I will be sending mine in for seal work and will ask the prop shop in Boise what their opinion is.
S
Rich[/quote]

Apparently he's talking about the electric three blade. There are bunches of three bladed MT props on Huskys (and are installed at the factory) and more every day on other O-360 powered airplane's, but theses are all oil governor actuated.

MTV