2 vs 3 bladed prop

Jmcmanna

Thinking about propellers, and after talking with Joe the prop guy, I'm wondering what the general thoughts are on 2 vs 3 bladed propellers. It looks like someone could get a composite 3-bladed prop for a little over $12,000, vs a 2-bladed one for $9,400. I hear that 2-bladed props are a little lighter, faster, and noisier...vs quieter and less vibration in the 3-bladed version. Plus, the 3-bladed one does look a little cooler on the ramp

I did some Googling, but I am looking for some personal opinions, too!

Harley Kleemann

Yes, three blade props are quieter, but, as you stated, they are heavier and slower in cruise vs. a two-bladed prop. A friend of mine replaced the McCauley prop on his Arrow with a Hartzell three blade prop, and he lost over 2 kts. in cruise performance. His plane also gained almost twenty pounds of nose weight because of the prop.

arrow76r

I have heard the same thing. Loss of cruise speed may be due to turbulence caused by the preceding blade in a 3 blade prop whereas in the 2 blade prop the turbulence may be less or none. Years ago I had to buy a new prop and it was suggested to buy a 3 blade unit because the prop shop had those in stock but said I might wait for a while until Hartzell made a run of 2 blade units because people were not buying many of them. Turned out they found a 2 blade prop which I bought...cheaper and I don't need the climb performance advantage purported for a 3 blade but I do need the cruise speed...the more the better!!

Harley Kleemann

There's an STC to install a Hartzell two-blade Scimitar prop on an Arrow. If I ever have to buy a new prop, I'll really consider that route.

Jmcmanna

I think I will be going with the two blade scimitar prop, as a matter of fact.

arrow76r

Yes, me too! When I bought the one I have, there wasn't an STC available. A friend of mine has a Mooney with the same engine and prop and he replaced his old prop with the scimitar and claims it makes cruise faster.

Jmcmanna

As far as propellers go, it looks pretty cool!

https://www.knots2u.net/piper-pa-28r-propeller-2-blade-hartzell-scimitar-ppi-28/

Now I just have to figure out what to do with the old prop....

Harley Kleemann

Jim, you can always list it on Barnstormers...

Scott Sherer

Hi Jim,

In the hangar across from me is an Arrow 200 with a three blade prop. I can put you in touch with the owner, Bob, if you want to talk to him about it. Here's a picture.

kzadora

Jim, I would approach the problem from the perspective of "given my preferences, what is the best propeller on the market for my airframe-engine combination"? For example, I do not care that much about the looks or speed, but I do care very much about noise and vibration, so losing 2 knots in cruise in exchange for noticeable reduction of noise would be a no-brainer "yes!", but you might have different preferences.

I bought my Arrow from a flight school that is also a reputable propeller shop. They cared for the propeller and the whole airplane well. I have a 3-blade McCauley, and combined with the Continental TSIO-360 it is pretty much the smoothest combination I have ever flown. I am sure much of that is just good maintenance and balancing, but I do believe the 3-blade design has inherent advantages when it comes to vibration and noise. The propeller has plenty of life in it and I am planning to overhaul it later this year, but when the time comes, I will take a hard look at what is available on the market. For example, on the Facebook PA-28 flyer/owner group I have seen reports from Arrow owners who were very happy with the MT 3-blade composite propeller upgrade. In this case the manufacturer and the users both report a small increase in the climb and cruise performance over the 2-blade prop. So that prop will be definitively on my shortlist, in addition to whatever McCauley offers.

Hope this helps! Cheers!
Karol

Harley Kleemann

Looks like I'd be out of luck if I wanted to use an MT prop, there is no STC in the USA for a PA28RT-201.