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acclaim with type s composite prop


pkofman

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I might not state this correctly but . Does anyone think that it is worth it to spend the money on a type "s" composite  prop on a "non-type - s  2018 acclaim". Evidentially there is an stc per below. Is there a big  performance advantage to be gained? My plane has tks so that would be part of it.

Peter

"Structural Composite Upgrades

STC SA02482CH allows the installation of Hartzell’s N7605C-2 Advanced Structural Composite ASCII three-blade propeller, which has become a common sight at airports due to heavy usage on Cirrus SR22T, Piper Mirage and Matrix, Diamond DA40XLT and other top-of-the-line models. In addition to better performance than many of the earlier models, the lighter 64 lb. weight is a plus along with increased durability and repairability of the carbon fiber blades with impact resistant nickel-cobalt leading edges.

It is available plain or with TKS ice protection. An anti-ice slinger kit can also be included for conversion from the two-blade propeller. Pricing on the all carbon ASCII structural composite propellers for Mooney aircraft ?

 

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I went with the S-type prop as a replacement... on the O...

Choices...

1) Thick blades...

2) Thin blades...

3) MT composite...

4) I was looking to shave a few pounds off the nose...

5) MT hadn’t delivered the first prop for the O yet, timeline was unknown...

6) MTs have a lot of good pireps lately...

7) I don’t fly enough to make good economic sense out of the thick blades...

8) Sound profiles of MT’s composite blades are interesting in how quiet they are...

9) The missing fly-wheel affect used to make me wonder if that would be OK...

10) Swapping out a perfectly good prop never crossed my mind...   :)

11) I haven’t heard from anyone with a Hartzell composite prop... does it exist yet?

 

For better logic than mine... I always refer these questions to @StevenL757

PP thoughts about props for the long bodies...

Best regards,

-a-

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1 hour ago, pkofman said:

I might not state this correctly but . Does anyone think that it is worth it to spend the money on a type "s" composite  prop on a "non-type - s  2018 acclaim". Evidentially there is an stc per below. Is there a big  performance advantage to be gained? My plane has tks so that would be part of it.

You stated it fine.  Acclaims starting with S/N 31-0090 (may have been 31-0100) were built with Type-S modifications by default.  There were no non Type-S Acclaims produced after that.

Other than a weight reduction, appearance, and repairability, there is no takeoff performance or cruise speed advantage between this prop and the aluminum 72.5-pound F7498 prop.  For the privilege, you get to fork out around $23k - $25k at last look, including TKS overshoes and parts.  It may have gone up since then.

Steve

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2 hours ago, Robert C. said:

If you're thinking of getting a new prop you owe it to yourself to look at the 4-blade MT prop. Saves about 30lbs in weight as I recall and will give you better take-off distance and 2-5kts faster cruise when you get above 10k.

The MT’s only real benefits on the Ovation are looks and a weight savings.  It actually gives about 1 to 2 knots less cruise performance than the F7498 Hartzell, and about the same cruise performance as the Hartzell composite.  A significant “gotcha” I learned that Ovation owners should know when considering the MT flavor is the aft shift in CG over heavier metal props.  Another member here who removed his F7693DF-2 Hartzell in lieu of the MT experienced a notable increased wear of his landing gear shock discs over a relatively short time (less than 2 years), verified by his IA after observing the aircraft for some time following the MT installation.  I’m not clear on whether any Charlie weights were removed to help compensate for the shift tho.

The prop weight differences are...

  • Hartzell F7693DF-2:  80 pounds
  • Hartzell F7498:  72.5 pounds
  • Hartzell Composite:  64.0 pounds
  • MT Prop Model MTV-14 (anti-ice):  63.7 pounds
  • MT Prop Model MTV-14 (no anti-ice):  60.0 pounds
Edited by StevenL757
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1 hour ago, StevenL757 said:

The MT’s only real benefits on the Ovation are looks and a weight savings.  It actually gives about 1 to 2 knots less cruise performance than the F7498 Hartzell, and about the same cruise performance as the Hartzell composite.  A significant “gotcha” I learned that Ovation owners should know when considering the MT flavor is the aft shift in CG over heavier metal props.  Another member here who removed his F7693DF-2 Hartzell in lieu of the MT experienced a notable increased wear of his landing gear shock discs over a relatively short time (less than 2 years), verified by his IA after observing the aircraft for some time following the MT installation.  I’m not clear on whether any Charlie weights were removed to help compensate for the shift tho.

The prop weight differences are...

  • Hartzell F7693DF-2:  80 pounds
  • Hartzell F7498:  72.5 pounds
  • Hartzell Composite:  64.0 pounds
  • MT Prop Model MTV-14 (anti-ice):  63.7 pounds
  • MT Prop Model MTV-14 (no anti-ice):  60.0 pounds

I don’t understand - why did the shocks wear more quickly?

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17 minutes ago, Will.iam said:

Are there any 2 blade MT or composite prop for M20K? All I see are 3 blade. 

For MT... I don’t think so...  as I asked the same question the other day... and somebody explained that they had a three blade...

Best regards,

-a-

Edited by carusoam
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17 hours ago, aviatoreb said:

I don’t understand - why did the shocks wear more quickly?

Basically, removing 20 pounds of weight from the nose not only caused the tail to sit lower, but resulted in a change in moment and an aft CG shift by just over 1 inch.  Although "only" 20 pounds was removed, the added weight on the gear discs was impacted.  I have yet to figure out out more than that, but on the surface, this is what was observed before and after the prop replacement.

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1 hour ago, StevenL757 said:

Basically, removing 20 pounds of weight from the nose not only caused the tail to sit lower, but resulted in a change in moment and an aft CG shift by just over 1 inch.  Although "only" 20 pounds was removed, the added weight on the gear discs was impacted.  I have yet to figure out out more than that, but on the surface, this is what was observed before and after the prop replacement.

Could be.

I have not noticed an increased rate in puck wear when I changed props - 5 years ago?  In my case I took 35lbs off the nose in changing props and the CG moved a good bit.  But it moved it to about where it probably was when my plane was a normal M20K before the rocket conversion with the heavy engine and the heavy McCauley prop.  So I figure it is more balanced now and surely the pucks like that.

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20 hours ago, StevenL757 said:

The MT’s only real benefits on the Ovation are looks and a weight savings.  It actually gives about 1 to 2 knots less cruise performance than the F7498 Hartzell, and about the same cruise performance as the Hartzell composite.  A significant “gotcha” I learned that Ovation owners should know when considering the MT flavor is the aft shift in CG over heavier metal props.  Another member here who removed his F7693DF-2 Hartzell in lieu of the MT experienced a notable increased wear of his landing gear shock discs over a relatively short time (less than 2 years), verified by his IA after observing the aircraft for some time following the MT installation.  I’m not clear on whether any Charlie weights were removed to help compensate for the shift tho.

The prop weight differences are...

  • Hartzell F7693DF-2:  80 pounds
  • Hartzell F7498:  72.5 pounds
  • Hartzell Composite:  64.0 pounds
  • MT Prop Model MTV-14 (anti-ice):  63.7 pounds
  • MT Prop Model MTV-14 (no anti-ice):  60.0 pounds

Steven,

The OP flies seems to fly a Bravo and asks about doing this on an Acclaim. He presumably regularly cruises higher than an Ovation. The 4-blade starts to shine at higher altitudes as I understand it, hence my reference to "above 10k." Not mentioned in my earlier reply are the pireps of less noise and less vibration. "turbine smooth" is the phrase often used by those that enjoy their MT prop.

I had wondered about the CG shift. Thanks for reporting on that. I was assuming one would remove charlie weights to mitigate that.

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Oddly, a well balanced IO550 is considered turbine smooth as well...

When compared to Lycoming fours...

And having a Gami spread close to zero...

Now add an MT to that... 

It may actually be turbine smooth...   :)

More blades is good for getting off the ground and climbing....

The negative aspect is the increased drag of the extra blade area...

Flying high is pretty much the best way to make the added drag a non-issue...

 

PP thoughts only...

-a-

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I didn't know more blades was better at higher altitude. I rarely fly higher that 7,000 feet but yesterday I climbed to 10,500 and was surprised to see no speed loss which it should have like any naturally aspirated airplane. I didn't do a GPS so it maybe inaccurate. I am intrigued. I will climb to 11 and 12,000 today see how it works out. 

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