Good call...
I was planning on going with a Hartzell CS prop in my 7A but the recent increase in engine prices has forced me to reconsider. I have since been reading up on a Catto 3-blade as an alternative to save on total cost. My bias toward the CS prop was for not for aerobatics or formation flying but mostly for the takeoff performance (without sacrificing cruise) and better control of air speed in the pattern. Can any Catto 3-blade drivers comment on the takeoff, cruise, and braking performance of their 3-blade set-up?
John,
In a word, YES! In 98' I called Craig Catto asking whether his "Long-EZ" props would have RV applications. At the time I was flying my 150HP RV4 with an Ed Sterba prop. Craig not only loaned me a prop to experiment with, he applied the data to new airfoils applicable to RV power bands/speeds and torque. I flew the loaner (Glasair prop) for almost a year until my first "RV" 2 blade was ready.
The first flight was chased by an 180HP Hartzell RV6. Fighter Pilots being what they are, eventually a 1V1 ensued. The new Catto prop not only proved itself worthy but superior in all arenas except initial takeoff acceleration. Eventually, with practice (going to full throttle before lead) I was able to stay up with the Hartzell on formation takeoffs, amazing considering the HP difference.
Fourteen years later and three Catto props later, Craig's new blade design is even better than the original. My 150HP 2 Blade "RVX" has proven itself alongside many higher HP RV's, again and again with amazing performance. It's aerobatic prowess way outperforms my previous MT FP in the vertical. Here are some numbers:
RVX 150HP 2 Blade Catto NLE (nickel leading edge) Sea Level 80F
Static: 2100
Takeoff 2250 (70 Knot initial climb) 1000 FPM
Climb 2300 (100 Knots) 1650 FPM
Climb 2400 (120 Knots) 1100 FPM
Climb 2500 (140 Knots) 750 FPM
Cruise SL WOT 177 Knots IAS 2850 RPM and smooooth.
Cruise 11,500 WOT 138 KIAS 170 KTAS 2700 RPM
Having flown many Catto Three blades They are well matched for the tri-gear RV's in performance vs ground clearance. The 2 blade has the edge in performance on the 0-320, the three blade a bit better on the 0-360. As far as braking goes, slowing down with a FP prop is directly proportional to "the nut behind the stick". With practice you can acceptably slow down, (not as good as a C/S "airbrake") but safe and proficient. My technique is to insure my engine idle is set at 700 RPM or less. Really helps. Just like in a T-Craft Jet or any other clean airframe, pointing the nose at the runway only increases airspeed and extends your touchdown point. Pulling the nose up, slowing down and using power to control your touchdown point is key.
Either way, a win-win.
V/R
Smokey