2 blade vs. 3 blade props

[meritflyer]

There seems to be a very distinct crowd in the CFI/owner/GA community regarding 2 blade vs. 3 blade props.

I sat with a group of novice CFIs and plane owners recently and watched them have it out. It was comical to say the least.

The 2 blade crowd says that they can get climb rates as good as the 3 blade crowd but get better speeds in cruise.

The 3 blade crowd says they get better hole shots (faster acceleration on takeoff), better climb rates, and comparable cruise speeds.

There are apparently some new, very advanced 2 blades that have come out. Aerodynamically, I've always thought the two are comparable.

 

[wjmiller3]

If a little is good, a lot MUST be better!!! I always thought these looked cool:

 

[Cptnchia]

Why do I have a two bladed prop on my plane?

Because it came that way from the manufacturer. If it was good enough for them to put it on the plane back in 1947, why mess with it now.

 

[esa17]

Three blades are much smoother and give you a touch better climb. Three blade scimitars are the cats-arse since they are so quiet. Sure, you lose a knot or two at cruise because of the extra blade but the real benefit is the ride.

 

[Roger, Roger]

A Cessna 185 with the 2-bladed prop is ungodly loud for a piston single running only 6 cylinders. The 3 blade is a lot quieter, and therefore not as cool.

 

[Inverted25]

We have two 182rgs. One with two blade prop. One with a three blade. The difference ???? Fly the same to me. The only difference is one has electric trim on the yoke which is wonderful.

 

[Minuteman]

On airplanes with a choice between two or three-bladed props, does the engine make the same amount of power? Does the tachometer's green arc have the same boundaries?

 

[KSCessnaDriver]

On airplanes with a choice between two or three-bladed props, does the engine make the same amount of power? Does the tachometer's green arc have the same boundaries?

When the DA-40 in my avatar went from the 3-blade wood-composite prop to the 2 blade metal scimitar, nothing changed on the tach (G1000), as far as I know. The only difference before versus after was a slight reduction in climb speed and a fairly decent increase in cruise speed (went from 130ish KTAS to close to 140 KTAS).

 

[Orange Anchor]

The Russians have liked many blades and counter-rotating props for a long time. AN-70

 

[stratoduck]

Is it worth bringing up the single bladed prop for the Continental 65? It was counterweighted and allowed a slight rotation that gave it a small change in pitch. It claimed to climb and cruise better than the two bladed props of the time. My grandfather met a guy back in the 1940's with one on a Taylorcraft that substantiated the manufacturer's claims. The only thing I've ever found concerning this prop are old ads. Seems to have completely disappeared from aviation rather quickly. I would love to hear if anyone knows of what happened to the product.

 

[Blackhawk]

Three bladed MTV-9 prop eliminates the 2000-2350 RPM limit on the 8KCAB.

 

[ProudPilot]

Is it worth bringing up the single bladed prop for the Continental 65? It was counterweighted and allowed a slight rotation that gave it a small change in pitch. It claimed to climb and cruise better than the two bladed props of the time. My grandfather met a guy back in the 1940's with one on a Taylorcraft that substantiated the manufacturer's claims. The only thing I've ever found concerning this prop are old ads. Seems to have completely disappeared from aviation rather quickly. I would love to hear if anyone knows of what happened to the product.

Oh I'd love to see a picture.

 

[Blackhawk]

Oh I'd love to see a picture.

http://www.ultraligero.net/Cursos/varios/helice_de_una_pala.pdf

 

[K-Train]

A Cessna 185 with the 2-bladed prop is ungodly loud for a piston single running only 6 cylinders. The 3 blade is a lot quieter, and therefore not as cool.

:clap:

 

[Baronman]

I thought 2 bladed props give higher cruise speeds but are generally louder than 3 bladed props.

At Flight Safety we had a fleet of Senecas with 3 bladed props, and only one aircraft with a two bladed prop......The 2 blade airplane cruised about 5-10 kts faster, even flying together once the guy in the 2 blade prop passed me easily.

 

[tlewis95]

I have always liked the single blade idea. It is very popular on the Silent self-launch sailplane series here that are in production currently.

 

[OhioStatePilot]

Just from looking at the single blade idea, I know they use counterweights to dampen vibration, but wouldn't the fact that lift is only created on one side of the hub create serious wear concerns for the prop shaft/bearings?