Expert: Paul Soderman - 10/4/2008

Question
Will a 3-blade propeller on a Cessna 182-L outclimb the same airplane with a 2-blade prop?  Our flying club is considering a switch to 3-blade for improved ground clearance and climb performance.

Answer
Probably, but at the cost of less cruise speed.  But I can't say definitively without knowing more about your propeller performance, engine, aircraft weight and drag, and mission.  You really need the propeller performance maps that show propeller efficiency versus advance ratio for various blade pitches.  Blade number and diameter also enter.  Those curves exist for every propeller.  See the following reference for more details:
http://www.epi-eng.com/propeller_technology/selecting_a_propeller.htm

The authors actually calculate the optimum propeller diameter for a given horsepower and blade number.  I don't know how accurate it is, but it is a good place to start.
Paul