2-Blade VS. 3-Blade prop
I have a PA32-300 with the prop off at the prop shop to be overhauled. Prop shop called and said the blades are not servicable. They gave three opptions- 1."If" they can find servicable blades go that route @ $1600-$1800 each 2. New blades @ $2800 each or 3. 3-blade conversion for about $7000. At first glance you would think no brainer and go with servicable blades, But you have to through in another $2300 for what was done to the hub which would bring you back up to almost $6000, only a cool grand away from the 3-blade conversion. I know the 3-blade will give you more ground clearence and a better climb but aside from that I don't know anymore advantages or any disadvantages of the 3-blade prop. Any ideas or suggestions???
Comments
With the AD on the hub (if that applies to you), I opted to go with the 3-blade just to get far away from that. I like my prop and would like to keep it on the plane for a while - at least while I'm flying!
It says due to new airfoil design that it is faster and more quiet. The ad doesn't really say compared to what (the 3 or 2 blade) it is supposed to be better.
It's not so much that the 3-blade generates less noise than the 2-blade, but that the noise is shifted in frequency due to the fact that the blades are shorter. Being shorter, the tips don't travel as fast.
Due to the extra blade, the vibration pulses are closer together in time (higher frequency) as well, so you don't feel it as much. It probably also makes is easier to get good dynamic balancing than with the 2-blade - just a hunch.
Hunh? Of course you can! Am I missing something?
I don't think you're missing anything. The Guest who posted that either has no idea what he's talking about, or he has some obscure definition of "dynamically balance" that he's decided not to share.
Hey @STARCH this was written over a decade ago but now I'm finding myself in the same situation... Did you ever make a decision or find a resolution?
Did you go with the three blade conversion? why or why not?
If you have the AD hub, it’s a no brainer. But also accept that the WB will move forward if you do and weigh more than the 2 blade.
Also understand that 2 blades are more efficient than 3. So either you accept the weight and WB penalty for the cool look or you keep the 2 blades and know your using power more efficiently.
Take a look at MTs composite props if your checkbook can handle it.
I own and fly a 79 PA32RT-300T. Previous aircraft are a 79 Archer and 76 Arrow.
Part of the decision will likely focus on availability. Am seeing where getting a 2 blade setup is turning into a challenge and 3 blade is more likely to have current, or near term, availability.
For the weight penalty of going with an extra blade, there is a composite prop. But do not recall whether it has a STC for the PA-32. Another factor is that IIRC it has a 7 year life.
https://mt-propeller.com/en/entw/stcs/pa32_1.htm
I own and fly a 79 PA32RT-300T. Previous aircraft are a 79 Archer and 76 Arrow.
Money aside, when I was at the same decision point as you, I went with the 3 blade over the 2. I found the key reason to be noise. In my case, I fly with a friend who owns a similar PA32-300 to my own (his is retract and mine is fixed gear). His was noticeably quieter than mine and even with good headsets I found myself a little less fatigued when flying in his after a long flight. Further, I believe it makes the airplane look better and will reap a higher return when I sell. Nothing technical to throw at you other than my 2 cents worth of opinion.
We installed a 3 blade Hartsell on our PA 32 and are happy with it. Most people are trading a worn out 2 blade fo a new 3 blade, so it’s difficult to evaluate.