I never saw a 337 with 3 blades props. Don’t you think that it would be an improvement for the plane?

Guess you haven't seen enough of them... There is even an "Ultimate 337"

Twin turbocharged, twin inter-cooled TSIO550 Continental engines with

3-blade Hartzell propellers on both front and rear

Claims to have 300mph with that 700 horsepower!

You really don't see to many Skymasters with three bladed props but there are a few.

Here's the "Ulitmate" information

http://www.aviationenterprises.us/

The Hartzell props are available, they generally will result in better climb and less speed which sorta keeps people from the mod! I think MT also has a 3 bladed prop which is STC'd for the Skymaster.

Edit -- It does change that unique sound they make overhead!

3

Mt Props

Generally, the horsepower of an engine determines the number of blades for the propeller that is attached. The most aerodynamically efficient propeller is a single blade. That has difficulty for obvious reasons, so two blades are installed...

More blades are less aerodynamically efficient, so the are added only if necessary.

Advantages - lower noise

Disadvantages - less efficient cruise, expense of modding the airplane and overhauling the prop

I think it would be great. They are bloody noisy now. I wouldn't imagine 550s would be quieter that 360s, even with 3 bladed props.

in some ways yes in others no prop wake etc its complicated besides then the FAA has to stick there nose into the mix for an STC

with its HP rating its just into the range where it would be useful

Hell; I can do better than that; how about a CESSNA 337 with ONE ENGINE and a THREE BLADED PROP.

LOOKEE HERE !

http://www.youtube.com/watch?v=DdrgG7O7j5c

Nothing can help the 337 Skydisaster.

Here is the specs for the STCd MT props. read aboput the improvement.

http://images.google.com/imgres?imgurl=http://www....

more blades made the resultant rotor disc performing BETTER. number of blades is mostly the result of engineering issues of complex rotor hubs.