What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Hartzell 3 blade

I'd be interested to hear what you find. From what I hear, 3 blades look cool on the ground, run smoother and might be worth a hundred FPM more in the climb or so, but they are harder to crate up for shipping (for overhaul), they make it more difficult to remove the lower cowling, and they are a few knots slower in cruise than a 2-blade.
 
I don't find it any more difficult to remove the cowlings on a 3 blade versus 2 blade. It is not the blades that get in the way, but rather the spinner backplate on any installation of RV cowllings.
 
My friend has one on a 9A...

I don't find it any more difficult to remove the cowlings on a 3 blade versus 2 blade. It is not the blades that get in the way, but rather the spinner backplate on any installation of RV cowllings.

... and he says it’s five times as hard to take the cowling off or put it on with the 3-blade on a nose-dragger. It may not be as big a factor with a tail dragger.
 
Has anyone gone with the 3 blade option for the 390 engine? Is the extra performance worth the extra cost?

Please cite the circumstances defining "extra performance". Are we talking cruise speed at high or low RPM, climb, gyroscopic behavior during aerobatics... What?
 
All else being equal, a 3-bladed prop offers little appreciable benefit in climb performance and, generally, a performance hit in top speed vs. a 2-bladed prop. Some think they look better on the ground, so if you're after 'show' rather than 'go' and don't mind paying extra for static looks, then have at it.
 
... and he says it’s five times as hard to take the cowling off or put it on with the 3-blade on a nose-dragger. It may not be as big a factor with a tail dragger.

The fix is to extend the slot in the bottom cowl forward, so you can lower the cowl more to clear the prop, while the nose gear leg goes thru the slot. But I agree with others, a 3 blade is for show, not go.
 
Back
Top