3-Bladed Hartzell Prop on the RV-10

rkbrown819 · #1 08-14-2019, 11:18 AM

Has anyone installed the Hartzell 3-bladed prop (C3Y1R-1N/N7605C) on their RV-10? From the Vans price list, it looks like it also requires the Hartzell Polished Spinner. It appears that the total added cost versus the Hartzell 2-blade blended airfoil prop is about $12,000. I'd be interested to hear from anyone that has experience (positive or negative) with the Hartzll 3-blade installed on their RV-10.

ReidVaitor · #2 08-14-2019, 10:18 PM

http://www.vansairforce.com/communit...ell+blade+prop

AviatorJ · #3 08-15-2019, 03:44 PM

I have it and I love it. Hit with the ladies and children alike!

rongawer · #4 08-16-2019, 11:21 AM

Another option is the HRT series from Whirlwind Aviation. The 375HRT is perfect for the IO-540 260hp and about $16K with the governor, spinner and hardware. Plus it's composite, meaning the blades are made of carbon fiber, providing a 3-blade prop that that weighs about the same as a 2-blade Hartzell metal prop.

However, what wasn't mentioned is that the most efficient prop is a 1 blade. If you want the more efficient prop in cruise, get a 2 blade.

Drag, much like gravity, is one of the laws that has to be dealt with; more blade area = more drag.

...now, where did I put my flame suit...

DRMA · #5 08-16-2019, 01:28 PM

Suggest you also look at the MT 3 blade prop offered by Vans as an RV-10 option. I haven't flown mine yet, but install was easy, and it has a bit more ground clearance than the other props (e.g. less opportunity for prop strikes). And it is several thousand $ less than the Hartzell 3 blade.

AA_RV10 · #6 01-26-2021, 01:32 PM

Quote:

Originally Posted by DRMA

Suggest you also look at the MT 3 blade prop offered by Vans as an RV-10 option. I haven't flown mine yet, but install was easy, and it has a bit more ground clearance than the other props (e.g. less opportunity for prop strikes). And it is several thousand $ less than the Hartzell 3 blade.

Hi Dave,

I am looking at the MT 3 blade as well. How does your cruise speed compare to other RV-10 operators with the Hartzell 2 blade? Any speed reduction? Is it as smooth as you hoped?

Thanks,

Chris

AlpineYoda · #7 01-26-2021, 01:48 PM

Haven't flown mine yet, but I went with the 2 blade Hartzell. I really really really really really wanted to have a three bladed prop. It looks sooooo cool.

But, after talking to about 12 experts, including even the team at Van's, I couldn't justify it. The only pros for a three are looks and maybe a smoother ride. Van's builder support said the 2 blade is at least 5 knots faster. Climbs better. Works better at altitude, too.

So, sadly, since I couldn't justify the cost for lesser performance, I went with 2 blades.

DRMA · #8 01-26-2021, 04:46 PM

I'm very happy with my 3 blade MT prop now that I'm flying with it, and am glad I made this selection.

Is it faster/slower than the 2 blade Hartzell? - I can't say as the only way to really know that would be to test my specific aircraft with each prop and compare. Every RV-10 is a little different, with different equipment, weights, and construction; all of which can impact speed by at least a couple of knots. (See Paul Dye's Jan. 2021 Kit Planes article on his replacement prop on his RV-8. He did direct comparison testing between his old and new props, expecting a small drop in speed with the new 3 blade prop, but didn't find it.)

Having suffered a prop strike once on another airplane, I wanted the extra ground clearance that comes with the MT prop on the RV-10. Will I ever need that additional clearance? - I certainly hope not, but we are all influenced by our individual past experiences, and so the extra cost of the MT prop was worth it to me for additional peace of mind.

Just another of the very many choices that experimental aircraft building provides.

Kahuna · #9 01-26-2021, 05:07 PM

Quote:

Originally Posted by AlpineYoda

Van's builder support said the 2 blade is at least 5 knots faster.

Vans is correct. There is same plane data to support it. Mine was ~7kts.

Quote:

Originally Posted by DRMA

Is it faster/slower than the 2 blade Hartzell? - I can't say as the only way to really know that would be to test my specific aircraft with each prop and compare.

Exactly correct. Discussions on mines smoother, mines faster etc have no real usefulness without same plane data.

I have also had the Hartz 3 blade composite on my plane. I cant find the data on it unfortunately. It was a number of years ago. It was used for testing. Was too heavy for my configuration on the Super 8 as I recall but it flew well and vib data showed it was quite smooth.
Who has same plane data on the MT vs others on the 540? Chime in.

Reflex · #10 01-26-2021, 10:18 PM

Nice comparison. Good to see somebody finally put a different prop on the same plane and made notes.

However, it should be noted that while the props were on the same plane, changing the length by 2" is likely to have a significant impact on performance. Seven knots is easily believable. Van's makes no recommendation on cutting the length when moving to a three bladed prop.

I spoke to multiple folks at Van's at Oshkosh a couple of years ago regarding 3 blade vs. 2 blade. The general consensus was that the 2 blade is faster. However, nobody had any hard data. In addition, there were two people I spoke to in the both that stated they believe the three blade is faster and climbs better...specifically the MT. Again, no hard data so support that opinion either.

Bottom line, right now on this board there is no hard data on the same plane being fitted/tested with multiple 2 and 3 bladed props and tested.