Elementary question to many of you, I'm sure.
What's the advantage of having a 3-bladed prop vs. a 2-bladed on a piston single?
Its quiter, and has more drag, so you can slow down a little faster. Though it doesn't seem to have the get up and go that a 2 bladed prop has.
You see 3-bladed props on the higher performance singles.
People buy three-bladed props because they tend to improve takeoff and climb performance. Cruise sometimes suffers. They're quieter due to reduced tip velocities. A shorter blade moving at 2700 RPM won't be moving as fast as a longer blade at the same speed.
And, almost everyone agrees, three-bladed props look cooler.
As for takeoff performance, I've heard mixed reviews
agreedAnd, almost everyone agrees, three-bladed props look cooler.
Yes.ALTHOUGH...single blade props are the most effecient design...but are there any?
People buy three-bladed props because they tend to improve takeoff and climb performance. Cruise sometimes suffers. They're quieter due to reduced tip velocities. A shorter blade moving at 2700 RPM won't be moving as fast as a longer blade at the same speed.
On a Piper Arrow it eliminates the restrictions on the RPM. With a two-bladed prop there is a limit on continuous operation within a certain RPM band, I forgot what it was but it's like 2200 to 2400 or something like that. At least on the 1970's models I was flying.
Yes. Sometimes it is an STC, sometimes it is part of the type certificate data sheet.I just figured more blades was the best way to transmit more power when you have a restriction on the blade length and, to a lesser degree, the range of RPMs (torque-y versus spinny ... what kind of RPMs did the Thielerts turn?).
But am I understanding correctly there is sometimes a choice of two or three-bladed props for the same size engine?
You may need to look at the STC or the type data sheet for the new limits. On my 8KCAB the RPM indicator still has the old limits marked on it, but the type data sheet removes the intermediate RPM limit and increases the maximum RPM.Interesting, I remember having the same restriction on 3-bladed Arrows I have flown. Maybe someone just hadn't gotten the memo where I was flying or something