Jump to content

Hartzell Acclaim 3 Blade vs MT Composite 4 blade?


Niko182

Recommended Posts

On 7/15/2018 at 3:20 PM, Niko182 said:

here it say full feathering. That's where i got that info from.
https://www.mt-propeller.com/pdf/stcflyer/FL061US.pdf


i believe MT doesn't offer a 3 blade and the 3 blade plastic prop that Hartzell offers i heard costs a fortune,
and looking at the specs, it weighs 3.8 lbs more. I wouldn't sweat the 3.8 lbs, but spending 10 extra grand,
to add 3.8 pounds is a little odd IMO. and paint is debatable. The paint on this plane is exceptional because
sat in a hangar for about 10 years, not really being flown. 107 hours have been put on the engine in the last 3
months, somewhat humorous, as its flown more in the last 3 months since new ownership, than it has in the
last 10 years.

Peter Reimer has had both the Hartzell 3 blade composite and the Acclaim 3 blade on his eagle. He can be authorative here. @N131MA Have your ears on?? (both are outstanding on the eagle, but the composite with TKS is quite spendy

 

Link to comment
Share on other sites

  • 1 year later...
On 7/21/2018 at 7:47 AM, mike_elliott said:

Peter Reimer has had both the Hartzell 3 blade composite and the Acclaim 3 blade on his eagle. He can be authorative here. @N131MA Have your ears on?? (both are outstanding on the eagle, but the composite with TKS is quite spendy

 

Any more info on this from an interested party?

Link to comment
Share on other sites

Id love the MT 4 blade, but I am not putting it onto my engine (TSIO520nb) until there is an STC for it...  Apparently there are concerns about counterweights with a lighter prop.  Until They have passed muster with the FAA, I am not going to seek a field approval by someone that goes " yeap, you fit it on there" and then go fly around.

I have to believe there is a REASON there is not an STC for my engine.

Link to comment
Share on other sites

1 minute ago, Austintatious said:

Id love the MT 4 blade, but I am not putting it onto my engine (TSIO520nb) until there is an STC for it...  Apparently there are concerns about counterweights with a lighter prop.  Until They have passed muster with the FAA, I am not going to seek a field approval by someone that goes " yeap, you fit it on there" and then go fly around.

I have to believe there is a REASON there is not an STC for my engine.

There is an STC for your setup. https://www.mt-propeller.com/en/entw/stcs/cessna_340_2.htm.

The reason there isnt an STC for the rocket is because an STC costs money and with the miniscule market of the rockets and missiles, it wouldnt be profitable. That STC above uses the same engine you do.

Link to comment
Share on other sites

Just now, Niko182 said:

There is an STC for your setup. https://www.mt-propeller.com/en/entw/stcs/cessna_340_2.htm.

The reason there isnt an STC for the rocket is because an STC costs money and with the miniscule market of the rockets and missiles, it wouldnt be profitable. That STC above uses the same engine you do.

Good to know, TY.

  • Like 1
Link to comment
Share on other sites

18 minutes ago, Austintatious said:

Id love the MT 4 blade, but I am not putting it onto my engine (TSIO520nb) until there is an STC for it...  Apparently there are concerns about counterweights with a lighter prop.  Until They have passed muster with the FAA, I am not going to seek a field approval by someone that goes " yeap, you fit it on there" and then go fly around.

I have to believe there is a REASON there is not an STC for my engine.


is your Rocket different than @aviatoreb’s?

STC available for his..?

Looks and sounds good too...

 

I held off... waiting for the STC for the O... The Bravo got it first... before the Ovation got it... my need came up prior to the STC...

Best regards,

-a-

Link to comment
Share on other sites

Just now, carusoam said:


is your Rocket different than @aviatoreb’s?

STC available for his...

Looks and sounds good too...

 

I held off... waiting for the STC for the O... The Bravo got it first... before the Ovation got it... my need came up prior to the STC...

Best regards,

-a-

Pretty sure erik got a field approval

  • Like 2
Link to comment
Share on other sites

2 minutes ago, Austintatious said:

Good to know, TY.

Exactly - Niko beat me to it.  It is certified in the EXACT engine combination we have - the Cessna 340 AND the Cessna 414 both use our TSIO520NB and the prop is certified for them.

http://www.mt-propellerusa.com/en/mtusa/stcs/cessna_414_2.htm

They just made a business decision that there are not enough of us Rockets out there to make an airframe specific new round of testing - so I have mine on a field approval.  Its all legal, and I am happy with it as being through the STC process for the engine, and I am fantastically happy with it in several of the many ways for its performance.

  • Like 1
Link to comment
Share on other sites

On 7/15/2018 at 7:33 AM, StevenL757 said:

Niko, your points for each are largely-accurate.  I’ve done this homework several times throughout the last few years on my own aircraft before making a decision, and based on discussions I’ve had with leadership and engineering folks at both MT and Hartzell.  Here’s the summary...

- The MT will dramatically outperform the MacCauley 2 and 3-blade options for takeoff and cruise performance

- The MT will outperform the Hartzell “7693” model (the “standard” Hartzell scimitar prop), but only by a few knots

- The Acclaim Type-S prop (“7498” model) will perform similarly to the MT, and on some airplanes, possibly outperform it in cruise

- Last cost I had quoted on the MT (about 3 weeks ago) for the Ovation is $20,127 without TKS parts, and around $21,700 with TKS.  A price increase was likely in the short-term

- The 7498 was between $15k and $17k list cost, but can be had for (realistically) $14.7k (no TKS) to $16’ish (with TKS)

- If your goal is more useful load and a bit quieter operation, then the MT is for you.  Otherwise, you should go with the 7498

My IA in San Marcos, TX is in the process of pulling a 7693 and installing an MT on an Ovation right now.  I can put the two of you together for a quick call if you want a first-hand account of the process and observations, so let me know if you want his contact info.  He is happy to share his experiences to help you make a decision.

Steve

I was recently instructing someone that purchased an Eagle 2 with the 3-blade McCauley (same prop as the O1) and back to back flights compared to my Eagle with the 2 blade McCauley left me with the impression the 3 blade is smoother.  The 2 blade however is much more efficient and performs better than the McCauley 3 blade in pretty much every other respect.   Thus, I'm Interested to see if there are any more Pireps to compare the 2 props the OP asked about along with FF numbers and TAS in cruise plus whether or not your bird carries TKS and/or A/C.  Trying to compare apples to apples for cruise performance.

My impressions to date of prop options:

3 blade McCauley (O1 & Eagle 2) - smooth but by far the least performance of any other option for the R & S model. I've been in both an O1 and Eagle 2 and neither were very speedy or overly impressive climbers.

2 blade McCauley (Eagle 1 only) - not quite as smooth, but efficient and speedy.  My bird has GAMIs and a K&N filter (no AC and no TKS)-  I can routinely count on 15-15.5 gals. FF +/- to turn in 184 KTAS at altitude.  Pushing more FF yields a few more knots - to date when I pushed FF up have seen as high as about 188 KTAS but it seems to take almost an extra gallon of FF for each knot over 184, so that seems the happiest place to fly when I need to cover long distances quickly.  I've never flown an O2, which uses the ever so slightly more efficient prop, but I flight plan using O2 book numbers for cruise speed / fuel burn and my numbers are routinely very close to O2 book numbers. 

3 blade Hartzell - I did a demo flight a while back in an Ovation converted to one of the Hartzell 3 blade props, 2700 RPM limit but at the time did not realize there were 2 Hartzell versions, thus unsure which prop this bird had.  Climb rate was impressive.  This bird had A/C.  PIC insisted on flying at high power setting and I seem to recall FF was somewhere in the 18.5-19 gals/hr range.  My calculations from this flight are that this bird needed about 3-4 gals FF more per hour to match the cruise speed of my Eagle 1.  Not sure if higher FF was solely due to the A/C or whether the prop was also less efficient since with AC it is not an apples to apples comparison.

To summarize - wondering what TAS and FF R or S model owners of non-AC/TKS birds are seeing with either the Acclaim prop or the new MT scimitar composite.  I'd be interested in gaining less vibration than my 2 blade but if either the Hartzell or MT turns out to be less efficient (more fuel flow to match speed), it may not be worth the significant investment.

 

 

Link to comment
Share on other sites

8 hours ago, Chris K said:

To summarize - wondering what TAS and FF R or S model owners of non-AC/TKS birds are seeing with either the Acclaim prop or the new MT scimitar composite.  I'd be interested in gaining less vibration than my 2 blade but if either the Hartzell or MT turns out to be less efficient (more fuel flow to match speed), it may not be worth the significant investment.

Expect non-TKS Ovations to be 3 - 4 knots faster than those with TKS. The MT 4-blade...although lighter than the 7498 (Acclaim Type-S) prop...will perform similarly to the 7498, but not outperform it.  Unless your goal is strictly to save weight and enhance appearance, the MT isn’t worth the extra $6.5k over the 7498.

As I’ve said many times here, the best cruise performance and engine management technique for our tuned-induction 310hp-equipped Ovation or Eagles with either Hartzell option or MT prop option is obtained at 2550rpm in cruise, 23in MP below about 7000ft (wide-open throttle above that), and LOP.  This coming from original designer/STC holder of the 310hp STC.

To answer your question:  With the 7498 prop installed, I see - generally - 172ktas and 13.2 - 13.4gph under the following parameters...

  • 8000ft
  • Wide open throttle (23.2in MP)
  • 2550rpm
  • LOP
Edited by StevenL757
Content
  • Like 1
Link to comment
Share on other sites

expect to run into 2vs 3vs 4 blade air resistance discussions for this...

Typical performance for a 200hp Mooney the three blade prop may climb slightly better than two blade, but the speed in cruise is often better for the two blade...

Now... extend that same argument to the 300hp Mooney... It is really tough to deliver all 300 hp and only have two short blades to do it with.... so T/O and climb are not as strong... but the air resistance of not having a third blade is interesting....

So.... a general rule of thumb... for Mooneys... add a blade for each 100hp...

It will always be a compromise between T/O and climb vs. cruise speed...

If you have a short runway... go with more blades.    If you have 10k’ long runways, flaps are no longer a necessity... :)
 

PP thoughts only, not a mechanic...

Best regards,

-a-

Link to comment
Share on other sites

Now that MT has a lot of props in service, ask around about durability. You will find two complaints: leading edge cracks & loss of filler, and, grease leaks. Leading edge problems require blade overhauls. So the prop comes off and you're down a week or so if they have exchange blades. Or 3-4 weeks if they don't. I've never seen this problem on Hartzell composite props. Only the MT props.

MT seems to have an unsolvable grease leak problem. Since there are no grease fittings, you just can't live with it while wiping it down and re-greasing. You remove the prop, have it resealed, and it may or may not leak again in 20 hours. 

Link to comment
Share on other sites

14 minutes ago, philiplane said:

Now that MT has a lot of props in service, ask around about durability. You will find two complaints: leading edge cracks & loss of filler, and, grease leaks. Leading edge problems require blade overhauls. So the prop comes off and you're down a week or so if they have exchange blades. Or 3-4 weeks if they don't. I've never seen this problem on Hartzell composite props. Only the MT props.

MT seems to have an unsolvable grease leak problem. Since there are no grease fittings, you just can't live with it while wiping it down and re-greasing. You remove the prop, have it resealed, and it may or may not leak again in 20 hours. 

Knock on wood - (which is a joke since these blades are wood core) - I have not had a grease leak problem in 5 years now.

I think some of those leading edge problems are on blades from older generation build.  If you buy their latest blade production method which has some technical improvements and also an X-ray machine they use to look for a perfect build as quality control, and also you get the nickel leading edge treatment that you see in my pictures above, then this mitigates quite a lot the durability of the blades.

Link to comment
Share on other sites

7 hours ago, carusoam said:

expect to run into 2vs 3vs 4 blade air resistance discussions for this...

Typical performance for a 200hp Mooney the three blade prop may climb slightly better than two blade, but the speed in cruise is often better for the two blade...

Now... extend that same argument to the 300hp Mooney... It is really tough to deliver all 300 hp and only have two short blades to do it with.... so T/O and climb are not as strong... but the air resistance of not having a third blade is interesting....

So.... a general rule of thumb... for Mooneys... add a blade for each 100hp...

It will always be a compromise between T/O and climb vs. cruise speed...

If you have a short runway... go with more blades.    If you have 10k’ long runways, flaps are no longer a necessity... :)
 

PP thoughts only, not a mechanic...

Best regards,

-a-

I've said before - but hey - nothing wrong with repeating...

At least for the old McCauley round tip 3 blade that I replaced the aerodynamics of that prop were based on 1960s design methods - slide rule and wind tunnel.  Good stuff - but the scimitar design of my MT 4 blade are modern CAD-CFD computer design and so much more aerodynamic.  So you can have your cake and eat it too in such a replacement.  More blades and more efficiency and speed.  I doubt you would get all that if replacing a more modern 3 blade.

Now 2 vs 3 vs 4 - you get more ground clearance with more blades as well which is nice.  Very nice, in a low slung mooney.

...and a bunch more good stuff.

  • Like 1
Link to comment
Share on other sites

Keep an eye on The blade clearance... 
 

Often Mooneys use the same prop arc diameter, no matter what the number of blades is... 2 vs. 3...

One way the MT can make the prop quieter... add the extra blade, and shorten the arc.
 

I need an all composite Mooney, with a composite prop, pressurized and turbine...   :)

Similar to Turbine Tom’s plane, but with a noticeable difference at the back....

 

PP thinking out loud... Turbine Tom used to have a Rocket.... while warming up for the turbine...
 

Best regards,

-a-

Link to comment
Share on other sites

On 7/18/2020 at 1:32 AM, carusoam said:

expect to run into 2vs 3vs 4 blade air resistance discussions for this...

Typical performance for a 200hp Mooney the three blade prop may climb slightly better than two blade, but the speed in cruise is often better for the two blade...

Now... extend that same argument to the 300hp Mooney... It is really tough to deliver all 300 hp and only have two short blades to do it with.... so T/O and climb are not as strong... but the air resistance of not having a third blade is interesting....

So.... a general rule of thumb... for Mooneys... add a blade for each 100hp...

I followed all the usual threads both in this forum and elsewhere before I bought my Eagle and was convinced the prop would have been the first thing to be switched in favor of the 7498 Hartzell so I could have a "screaming Eagle".  I'm glad I spent time flying the airplane before dumping the prop immediately because the airplane is much quicker than the POH and reviews suggest.  Both the Eagle 1 and O2 props were newer designs specifically for the airframe/engine combination and both were efforts by Mooney and McCauley to maximize cruise speed.  Due to the takeoff/climb performance complaints O2 pilots had, Mooney later switched to the Hartzell 7396 - a performance review of both the O2 two blade prop and Hartzell 7396 were published in MAPA and the conclusion is what we all know - the Hartzell climbed and accelerated better, but the O2 2 blade prop still bested the "newer" Hartzell prop by a fairly significant margin in cruise.  We all know now not to buy the 7396.  

Now for the 7498 prop - I'm certain it will accelerate on the runway better than a 2 blade and will achieve better Vx and Vy numbers.  Mooney's website seems to publish numbers for the M20U that do not seem realistic from a fuel flow perspective.  Top cruise speed range published seems to indicate 15-16 gals/hr FF for 197 KTAS and max range indicates < 11 gals/hr FF for 170 KTAS.  Avweb has a video of a review of the aircraft which they demo fly at 4k with a 174 KIAS for 18.4 FF and 164 KIAS for 13.7 FF.   Pretty decent numbers if indeed they were straight and level (later views in the video shows them in a constant descent).  They never did say what the speed at 8k or higher altitude was in that video (a chart later in the video seemed to suggest lower than 185KTAS??).  Nevertheless, 164 KIAS for 13.7 FF is efficient.  At that altitude and FF, I'm probably around 160 KIAS.  Now the M20U does have additional aerodynamic add-ons (wingtips, cabin and added fillers), so that would not be an apples to apples comparison for prop change alone.  

If someone is near me with a 7498 prop Ovation or Eagle, it would be a nice comparison to fly the 2 planes back to back for comparison sake. Otherwise some actual data about FF and TAS comparison would help to separate fact from hype about the propeller differences.

Link to comment
Share on other sites

I also spent some time with the 2 blade and personally wasn't a fan. Yes, the 2 blade is faster, but you pay the price for a lot of things, such as lower and slower climb, take off distance, landing distance, and weight.

My 2 blade prop had 1500 hours on it and was leaking quite a bit. We had the option of overhauling the 2 blade for around 3k, 

Or buying a top prop for 1900, a spinner for 300, and 0 timing that prop, while increasing the power and the useful load for 5 grand. That 168 lbs of extra useful load is something I have used quite a lot whether that be for fuel, or for packing 4 people in the plane. The screaming eagle package makes the eagle a whole different airplane

 

Link to comment
Share on other sites

1 hour ago, Niko182 said:

I also spent some time with the 2 blade and personally wasn't a fan. Yes, the 2 blade is faster, but you pay the price for a lot of things, such as lower and slower climb, take off distance, landing distance, and weight.

My 2 blade prop had 1500 hours on it and was leaking quite a bit. We had the option of overhauling the 2 blade for around 3k, 

Or buying a top prop for 1900, a spinner for 300, and 0 timing that prop, while increasing the power and the useful load for 5 grand. That 168 lbs of extra useful load is something I have used quite a lot whether that be for fuel, or for packing 4 people in the plane. The screaming eagle package makes the eagle a whole different airplane

 

Thanks Niko - so how much speed did you lose?  What is your typical FF and TAS?

Is your cost a typo at 1,900 or did you mean 19,000?  Was that prop only or plus the STC?  

I still have useful time on my prop, just thinking in advance when the time comes whether makes sense to keep the 2 blade or whether the 7498 has any speed or efficiency advantage.  I think you're one of the few people to come out and say the 2 blade is faster, wondering how much difference.  Runway length and climb are non-issues for me and I routinely see better than book.  Benefit for me would be some added smoothness.  For 25k cost I'd expect that it better go fast as well.

Link to comment
Share on other sites

38 minutes ago, Chris K said:

Thanks Niko - so how much speed did you lose?  What is your typical FF and TAS?

Is your cost a typo at 1,900 or did you mean 19,000?  Was that prop only or plus the STC?  

I still have useful time on my prop, just thinking in advance when the time comes whether makes sense to keep the 2 blade or whether the 7498 has any speed or efficiency advantage.  I think you're one of the few people to come out and say the 2 blade is faster, wondering how much difference.  Runway length and climb are non-issues for me and I routinely see better than book.  Benefit for me would be some added smoothness.  For 25k cost I'd expect that it better go fast as well.

Nope. I payed 1900 cash for a cirrus prop which is the same prop as on the ovation except the ovation prop is cut 2 inches in diameter. It had about 50 hours of flight and we simply just overhauled it to 0 time and cut it 2 inches, painted it, and it was practically new. Overhaul was 3k. Prop was 1.9k. Spinner was 300 bucks. Govornor replacement was 800 for an exchange. STC was 4995 with no tax since it was bought through agl. And labour was like 6 hours with so 700 bucks. That all adds up to 11500. I sold the old 2 blade for 1800 bucks. Honestly dont know how I got so much for it.

So all in around 9.6k for it all in. That included a useful load jump from 970 to 1130, a loss of about 2 knots, and a significantly increased climb rate and a significantly decreased takeoff roll. It probably is the only thing in aviation where I actually made money upgrading the aircraft. If only it worked out that way everytime.

 

I generally cruise around 10k at 176knots ish on 12.5GPH, and 179knots at 13GPH light. Add some people and take off maybe 2 or 3 knots at full gross.

  • Like 1
Link to comment
Share on other sites

On 7/17/2020 at 11:32 PM, carusoam said:

So.... a general rule of thumb... for Mooneys... add a blade for each 100hp...

But damn, those 4-blade setups look fantastic!  And, as a friend always says...if you can't be cool (I'm not), look cool.  :-)

Just be glad nobody makes a 1-blade configuration.  :D  Single blade wind turbines are odd looking affairs...

  • Like 1
Link to comment
Share on other sites

6 hours ago, Niko182 said:

Nope. I payed 1900 cash for a cirrus prop which is the same prop as on the ovation except the ovation prop is cut 2 inches in diameter. It had about 50 hours of flight and we simply just overhauled it to 0 time and cut it 2 inches, painted it, and it was practically new. Overhaul was 3k. Prop was 1.9k. Spinner was 300 bucks. Govornor replacement was 800 for an exchange. STC was 4995 with no tax since it was bought through agl. And labour was like 6 hours with so 700 bucks. That all adds up to 11500. I sold the old 2 blade for 1800 bucks. Honestly dont know how I got so much for it.

So all in around 9.6k for it all in. That included a useful load jump from 970 to 1130, a loss of about 2 knots, and a significantly increased climb rate and a significantly decreased takeoff roll. It probably is the only thing in aviation where I actually made money upgrading the aircraft. If only it worked out that way everytime.

 

I generally cruise around 10k at 176knots ish on 12.5GPH, and 179knots at 13GPH light. Add some people and take off maybe 2 or 3 knots at full gross.

Well that is interesting.  What was the part number of the cirrus prop and why was it so cheap?  So after cutting, is it the equivalent of the 7396 or the 7498 Mooney prop?  

Loss of 2 knots not so bad.  13 GPH, what power setting are you using?  Full MP, 2550 and LOP?

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.