New Hartzell Prop STC

[EricJ]

3 minutes ago, MikeOH said:

How does one deal with nicks, and such, in a carbon fiber prop?  I wouldn't think filing the edge is an approved method

Same as other composite props, like MT or wood or whatever.   They usually have a leading edge that is nickel or stainless or something.

[TheMooneyAnomaly]

22 hours ago, MikeOH said:

Can you verify the price is nearly $25,000?

I believe that is about correct.

[TheMooneyAnomaly]

21 hours ago, EricJ said:

There's not a lot more efficiency that can be squeezed out of modern propeller designs, so most of the innovations now are on reducing weight and reducing noise.   Don't expect anything to give you a significant increase in speed without somehow putting more power into it.

Well put.  Prop airfoil designs have been mighty efficient for a while. I have some adjustments to make before flying the test profiles again to have solid numbers to share.

[TaildraggerPilot]

25 Large for a two blade Mooney prop. Nah…..

[TheMooneyAnomaly]

On 7/3/2025 at 1:01 PM, ProtoFly said:

No biggie.  Just remove the Gill/Concorde Lead-acid battery and replace with an EarthX.  Between the prop and the battery, you'd pick up somewhere near 40 lbs useful load....

I transitioned to an EarthX in the rear empennage in anticipation of this change.  I would still like to move more weight forward and am interested in finding details on moving the battery to the avionics compartment.

[MikeOH]

18 minutes ago, EricJ said:

Same as other composite props, like MT or wood or whatever.   They usually have a leading edge that is nickel or stainless or something.

So, on the rare instance of damage to the face of the blade, the prop is trashed?  Or, is there an approved repair process?

[EricJ]

32 minutes ago, MikeOH said:

So, on the rare instance of damage to the face of the blade, the prop is trashed?  Or, is there an approved repair process?

Those are the details you learn in the manuals for the individual props.   Most composites have repair methods and repair limits.   Metal props do, too.

[MikeOH]

4 minutes ago, EricJ said:

Those are the details you learn in the manuals for the individual props.   Most composites have repair methods and repair limits.   Metal props do, too.

OK.  My question was based on thinking once the composite fibers were compromised (i.e. shredded) the integrity of the blade was destroyed.  Glad to hear there is some method to 'patch' a hole in the blade of a composite prop.

[StevenL757]

26 minutes ago, MikeOH said:

OK.  My question was based on thinking once the composite fibers were compromised (i.e. shredded) the integrity of the blade was destroyed.  Glad to hear there is some method to 'patch' a hole in the blade of a composite prop.

From the former head of Hartzell's Top Prop division - repair instances are unlimited, versus their life-limited metal counterparts.  In other words, there's only so much you can grind away from a metal prop before it's no longer serviceable.  Composite props are able to be machined and repaired to new standards over and over...essentially yielding a new prop with each successive repair.  Largely, for this reason, the $24k+ price is what it is.

[jetdriven]

5 hours ago, TheMooneyAnomaly said:

I transitioned to an EarthX in the rear empennage in anticipation of this change.  I would still like to move more weight forward and am interested in finding details on moving the battery to the avionics compartment.

So have you seen any increase in cruise speed or other performance with this prop? And were you compensated in any way or given a discount on this propeller to market it?

[Aerodon]

17 hours ago, StevenL757 said:

From the former head of Hartzell's Top Prop division - repair instances are unlimited, versus their life-limited metal counterparts.  In other words, there's only so much you can grind away from a metal prop before it's no longer serviceable.  Composite props are able to be machined and repaired to new standards over and over...essentially yielding a new prop with each successive repair.  Largely, for this reason, the $24k+ price is what it is.

MT  Propeller bragged about this too, but it turns out that their props are infinitely repairable as long as you bring infinite amounts of money to completely replace anything that might look like it is thinking of wearing out.

Aerodon

 

[jetdriven]

Yup it’s like George Washington’s axe. Replaced the blades twice and the hub once.  Still has 4000 hours since new.  

[Pinecone]

On 7/4/2025 at 10:31 AM, jetdriven said:

Not to mention the amp-hour capacity is half that of the standard rg35 battery.  

And they were on MS for a while and a number of us asked form them to make a bigger one. Double amp hours and still a good bit lighter.  But their answer was they knew better than us. 

Hmm Potential customers say make X and I will but it and they say nope you don’t know what you want.  Dumb

[PeterRus]

1 hour ago, Pinecone said:

And they were on MS for a while and a number of us asked form them to make a bigger one. Double amp hours and still a good bit lighter.  But their answer was they knew better than us. 

Hmm Potential customers say make X and I will but it and they say nope you don’t know what you want.  Dumb

To double amps just put two of these in parallel. 

[jetdriven]

49 minutes ago, PeterRus said:

To double amps just put two of these in parallel. 

STC doesn’t allow for that. 

[Hank]

58 minutes ago, PeterRus said:

To double amps just put two of these in parallel. 

 

8 minutes ago, jetdriven said:

STC doesn’t allow for that. 

And there's no physical space in my Mooney for another battery on my firewall. 

[BlueSky247]

I've been following this prop and am disappointed they didn't go with the name I'd entered into their contest. "Outlaw" to me sounds like some kind of bass fishing product or something, and doesn't befit the Mooney brand - just mho, and apologies to anyone affiliated with the winning name.

 

The pricing on this one had to be set based on expected sales, recouping r&d and stc costs, etc. While I'm sure it's a wonderful unit and probably does offer measurable improvements, it's way too high for my personal risk threshold. 

I honestly hope I'm wrong and that they sell a bunch of them. If they do, maybe that will encourage someone to pick up the speed fairings/aero mods side of things.

[1980Mooney]

On 7/4/2025 at 5:03 PM, StevenL757 said:

From the former head of Hartzell's Top Prop division - repair instances are unlimited, versus their life-limited metal counterparts.  In other words, there's only so much you can grind away from a metal prop before it's no longer serviceable.  Composite props are able to be machined and repaired to new standards over and over...essentially yielding a new prop with each successive repair.  Largely, for this reason, the $24k+ price is what it is.

This economic justification sounds great if you are operating off gravel runways and tearing the hell out of your prop every take-off.  But in reality, how many owners are having to scrap their metal prop blades frequently/regularly?   Most of us operate off of paved runways in decent condition.  I suspect that if you are scrapping blades frequently, it is more because of ham handed and overzealous A&P's that are unnecessarily grinding your prop down every year than the occasional fubar of a rock chip dressing/repair.

[Hank]

3 hours ago, 1980Mooney said:

This economic justification sounds great if you are operating off gravel runways and tearing the hell out of your prop every take-off.  But in reality, how many owners are having to scrap their metal prop blades frequently/regularly?   Most of us operate off of paved runways in decent condition.  I suspect that if you are scrapping blades frequently, it is more because of ham handed and overzealous A&P's that are unnecessarily grinding your prop down every year than the occasional fubar of a rock chip dressing/repair.

Our Canadian friends are required to overhaul their props at the recommended interval, IRAN notwithstanding. 

Here in the U.S., I've owned my Mooney for 18 years without overhauling my metal Hartzell prop . . .

[jetdriven]

On 7/20/2025 at 1:22 PM, 1980Mooney said:

This economic justification sounds great if you are operating off gravel runways and tearing the hell out of your prop every take-off.  But in reality, how many owners are having to scrap their metal prop blades frequently/regularly?   Most of us operate off of paved runways in decent condition.  I suspect that if you are scrapping blades frequently, it is more because of ham handed and overzealous A&P's that are unnecessarily grinding your prop down every year than the occasional fubar of a rock chip dressing/repair.

The Hartzell guys said there is a stainless mesh embedded into the prop and below that is the carbon fiber, and as long as it doesn’t go through the mesh, .020” or less, you can cosmetically repair it, but if it gets into the mesh, then you have to send it to an approved shop to have it repaired. If it goes completely through the carbon fiber plies into the core then the blade is scrapped.

Edited July 22 by jetdriven

[jetdriven]

For all the buzz about this $24,400 prop, it sure is crickets about any sort of performance advantages except for "a smoother ride "which is so subjective it's not even be measurable.  If they said it was worth 3 kn I was willing to pay for it at the booth at Oshkosh right now. But all I got was a whole bunch of nebulous "Well we don't know we were so busy doing the flight testing. We didn't bother to look at the airspeed."

Edited July 28 by jetdriven

[takair]

56 minutes ago, jetdriven said:

For all the buzz about this $24,400 prop, it sure is crickets about any sort of performance advantages except for "a smoother ride "which is so subjective it's not even be measurable.  If they said it was worth 3 kn I was willing to pay for it at the booth at Oshkosh right now. But all I got was a whole bunch of nebulous "Well we don't know we were so busy doing the flight testing. We didn't bother to look at the airspeed."

I’m kind of surprised airspeed sweeps, performance, and comparison to published book numbers wasn’t part of the certification…

[MikeOH]

2 hours ago, takair said:

I’m kind of surprised airspeed sweeps, performance, and comparison to published book numbers wasn’t part of the certification…

Or, just possibly, they don't want to share those results

[KSMooniac]

2 hours ago, takair said:

I’m kind of surprised airspeed sweeps, performance, and comparison to published book numbers wasn’t part of the certification…

I suspect some part of that is they don't want to advertise different performance numbers b/c it might trigger an expensive POH update that they don't want to do for every application.  That of course runs against every marketer's instinct as Byron pointed out he would pay for a few knots faster cruise!  

I'm very curious about it and had a conversation with a sales person in their display.  It is the lightest option for us, at 43 lbs vs. the MT at 46 lbs.  For some (dumb) reason they went with an aluminum spinner assembly instead of composite which boggles my mind.  I mentioned all of their cracking problems and I was assured they made a new spinner that doesn't crack, but it didn't fit this prop so they made another new one but she didn't think this one would crack.  Time will tell.  I asked if they had any flight test comparing it to the MT option and they do not.  I would love to fly back-to-back tests with my MT and see how it does.  I just spent a lot of overhauling my MT (including a replacement hub and bearings) so my upgrade budget is shot for the year, unfortunately.

[jetdriven]

They put the same prop on the Cessna Cardinal RG. And I think they sell it to experimental pilots too. But yet nobody seems to have gone out and documented any performance gains, and I'm really not interested in spending over 25 grand to be the first person to do it. It's almost like fight club, nobody wants to talk about it.