Two blade or Three blade?

[WaynePierce]

Why?

I'm leaning toward Three blade because there are a few grass strips I like.

[Hank]

I like the 3-blade on my C.

But you realize, the blades are the same length as on the 2-bldes? There's no additional ground clearance. 

I just spent last weekemd at a wet grass strip. Works fine . . . .

[aviatoreb]

4

[gsengle]

Depends somewhat on the model Mooney.


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[Raptor05121]

You get greater returns on the "big block" models but even on my lowly 180hp D/C, I would not go back to a 2-blade. It accelerates faster, shorter takeoff, faster climb rate...and looks downright gorgeous. I've flown formation with two other C models with 2-blades and at identical power settings, they have maybe 1-2knots on me, barring any instrument error

[carusoam]

With the Mooney ground clearance... Long props are out...

1 blade per 100 hp...

Three blade Top Prop, 310hp....

Why: Delivering power takes surface area, like the small wings that they are...

Cost: More surface area has a higher drag penalty...

Discount: Flying around in the flight levels, the air is very thin... the drag is very reduced. Four blades and vortex generators have minimal drag issues above 18k’.... and have really good added benefits down low...

Focus on the HP first, then how it is delivered... if your grass strip is shorter than 2k’ you really want to know about things that’s affect your T/O run... DA knowledge is a must.... stay light...

TopProp, MT prop, are more modern ways of delivering hp for Mooney planes....

Check your T/O run calculations for the set-up you are looking at... it isn’t an easy calculation to say that a two blade is better than a three blade... even though it probably is at getting off the ground....  as it is probably a few knots slower at 6k’...

PP thoughts only, not an aero-dynamicist.... 

Best regards,

-a-

 

[WaynePierce]

I had no idea there was not more ground clearance with  a three blade prop. That makes my decision process a little easier while looking for my next, new to me, airplane. Should be pre-qualified this coming week and then the shopping gets real.

Thank you all for your expertise and knowledge.

[carusoam]

Wayne,

One way to make comparative shopping interesting... see various Mooneys all in one place...

All American Aircraft in TX is an interesting visit...

https://www.allamericanaircraft.com/contact.htm

Click their inventory button to see what they have.

Visiting in person is a blast!

Use caution, it is very easy to overspend a budget.

If TX is too far, try your local MSC... Lots to look at, but they are mostly not for sale...

Enjoy the hunt,

-a-

 

[WaynePierce]

Already on a first name basis... they just need some J models. 

[Steve W]

As part of the repairs to my M20J I'm choosing to move from a 3 blade to a modern 2 blade. Some weight savings and maybe better efficiency. Would have gone with the MT 3 blade but the lead time seemed long. Although now it doesn't look like that would have been a problem.

[ArtVandelay]

Anyone with a MT on a J wish to give Pirep?

[carusoam]

@Alpineman probably wants to find this thread...

Best regards,

-a-

[carusoam]

6 hours ago, teejayevans said:

Anyone with a MT on a J wish to give Pirep?

@KSMooniac might have an MT answer...

-a-

[jackn]

The 3(4) bladed props look great!  The scimitars look really sexy & fast. But, I can remove/replace my cowling by myself, and (to me) the paddle prop of the mid-body just looks right for a Mooney. 

[Guest tommy123]

If your two blade is hitting things on a grass strip you have something serious wrong going on.

[aviatoreb]

1 hour ago, tommy123 said:

If your two blade is hitting things on a grass strip you have something serious wrong going on.

Very Long grass?

maybe it’s really a wheat field? Corn field?

[Raptor05121]

With this Florida summer rain, our mower can't keep up with how quick this grass grows. The tips of my 3-blade are routinely a shade of green

[KSMooniac]

[mention=6924]KSMooniac[/mention] might have an MT answer...
-a-

I put an MT on my J many years ago and remain happy with the decision. It is much lighter and smoother than any other option for our planes, and as mentioned is the only option that increases ground clearance. Removing weight on the nose is beneficial to the mid-bodies. Getting vibrations down to nearly zero improves fatigue life on nearly everything in the plane, and comfort for the people in the cabin as well.

It makes removing the lower cowl a bit more difficult, but it is not a show-stopper. I still manage to do it by myself often.

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[ArtVandelay]

I put an MT on my J many years ago and remain happy with the decision. It is much lighter and smoother than any other option for our planes, and as mentioned is the only option that increases ground clearance. Removing weight on the nose is beneficial to the mid-bodies. Getting vibrations down to nearly zero improves fatigue life on nearly everything in the plane, and comfort for the people in the cabin as well.

It makes removing the lower cowl a bit more difficult, but it is not a show-stopper. I still manage to do it by myself often.

Any change in performance? How much lighter is it?
Thx

[KSMooniac]

Better takeoff and climb than my original square-tipped 77 J 2-blade prop, and 12 lbs lighter. Cruise is too close to the same to note any difference.

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[rbridges]

On 8/4/2018 at 1:19 PM, Raptor05121 said:

You get greater returns on the "big block" models but even on my lowly 180hp D/C, I would not go back to a 2-blade. It accelerates faster, shorter takeoff, faster climb rate...and looks downright gorgeous. I've flown formation with two other C models with 2-blades and at identical power settings, they have maybe 1-2knots on me, barring any instrument error

people pay thousands for 1-2 knot speed mods.    I do agree with the ramp appeal.  A 3 blade looks good.  I think it's a mental thing for me, but I opt for best cruise speeds.  

[KSMooniac]

Forgot to mention that@testwest has a very accurate J performance model with different prop profiles so perhaps he'll chime in. I measured my prop details for input into the code, and he has the Hartzell Top Prop. The Top Prop I believe has the best cruise performance, but at higher weight (and vibration). I think he has the OEM prop data as well.

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[RobertGary1]

17 hours ago, tommy123 said:

If your two blade is hitting things on a grass strip you have something serious wrong going on.

I’d say of the published strips I’ve flown the Aeronca into probably 75% would cause a Mooney to dig dirt with the prop. There are some notable very well maintained grass strips that are equivalent to paved but your average grass field with deep gopher holes and uneven surface isn’t going to be Mooney friendly. And I’ve landed my Mooney on the beach jn Mexico several times so it’s no paved pincess  

There are far more dirt and grass strips in the US and Mexico id take my Bonanza into just because of the high clearance  If off roading is your pleasure you shouldn’t be looking at a Ferrari 

-Robert

[gsxrpilot]

Robert and I are always in disagreement here but I've just never experienced any issues with grass, dirt or gravel strips. I've only had my Mooney in to 10 or 11 of these strips and two of them were gravel. All were charted or published strips, but most were marked as Private. I've never felt that I came close to damaging my Mooney going in or out of any of them. And there are several more I intend to visit with the Mooney. 

For me the issue is generally length. With my 252 I like to have a bit more length than I needed with the M20C. Granted there are many other aircraft that are even better suited for grass strips. But since I live in Texas and the good grass strips I want to visit, are in Idaho, I need a fast traveling plane to take me there. :-) But once there, the Mooney seems to work well enough.

Take a look at piperpainter on youtube for some grass strip Mooney action. https://www.youtube.com/channel/UCeV3nI-kcmpeSzrBYOnMcdw

 

[RobertGary1]

41 minutes ago, gsxrpilot said:

Robert and I are always in disagreement here but I've just never experienced any issues with grass, dirt or gravel strips. I've only had my Mooney in to 10 or 11 of these strips and two of them were gravel. All were charted or published strips, but most were marked as Private. I've never felt that I came close to damaging my Mooney going in or out of any of them. And there are several more I intend to visit with the Mooney. 

You've probably been to nice well maintained grass fields. Nothing wrong with those, but they aren't the majority in my experience. Most don't have tractors to keep the field smooth or have pilots who care. If they're flying taildraggers they don't mind the ruts and holes.

-Robert