RE: Cool
Woweee that sucker really jumps up when it hits the pipe doesn't it? Last time I heard such a difference was when a certain dirt bike came up on the pipe when I wasn't expecting it, and I have the plate in my hand to prove it!
Aspect Ratio is why one bladers work better than multibladers, just like in Sailplanes, High aspect ratios deliver maximum lift for minimum drag.
3 bladers on PAMPA ships? Lets remember what they are dealing with, and I am going on speculation here but. They are dealing with a power band, delivered at a certain rpm on a certain pipe with certain fuel. This combination probably dictates a maximum diameter, multiple bladed prop to absorb and deliver the power at the correct rpm so that the engine can get up and down on the pipe at the ideal flying speed. Things evolve and everythgin is a compromise. I've no doubt that if the proper power band could be hit with a 2 blade prop, that'd be the way everyone would be going, it's cheaper and easier to install, trim and balance than a 3 blader. But I bet the wash from a multi blade prop is also more constant instead of the choppyness of a lesser bladed prop.
Or it could just be that a 3 blader looks cooler.
Aspect Ratio, that's the key though. Next is the Tip Vortices that was mentioned before, only one set on a one blader.