NEW! Ground Adjustable Composite Prop for Experimental Carbon Cub

[Pete D]

We flew it at one pitch setting only. At pitch setting that gave the same static RPM as the average Catto prop (about 2370 RPM on the ground) This gave approx 2700 RPM wide open, straight and level.

[armaurer]

We flew it at one pitch setting only. At pitch setting that gave the same static RPM as the average Catto prop (about 2370 RPM on the ground) This gave approx 2700 RPM wide open, straight and level.

Hi Pete,
Were you seeing any meaningful cruise speed increase?
Cheers
Alan

[Pete D]

The increase in speed was most noticable at wide open throttle. At 6,000 ft, 2250 RPM (LSA power setting) it was 106 indicated/115 true. I'd say generally 5-8 MPH faster but there are a lot of variables. C.G., weight, tire/gear size etc etc.

[turbopilot]

The increase in speed was most noticable at wide open throttle. At 6,000 ft, 2250 RPM (LSA power setting) it was 106 indicated/115 true. I'd say generally 5-8 MPH faster but there are a lot of variables. C.G., weight, tire/gear size etc etc.

Ok now for the details. I am working from memory on this so help me if my recollection is wrong.

Here is the placard for the "LSA Power Settings" for maximum continuous power.

VoilaCapture170-L.jpg
The last time I asked, this placard was based on an airplane with a fixed pitch prop that was considered a "climb prop" based on the pitch setting of that prop.

So... if you have a ground adjustable propeller set to a "Cruise pitch" setting, then the maximum continuous rpm limitation would have to be adjusted downward to stay with the maximum continuous power setting limitation.

All of this is another way of saying that if you were running a ground adjustable variable pitch propeller at a cruise pitch, then you were likely exceeding the maximum continuous horsepower limitation at 2250 RPM and 6,000'.

Maybe better to report cruise fuel flow as a proxy for engine power output when reporting cruise speeds at various pitch settings.

[WhirlWind Propellers]

Hello to the Cub Crafters Forum,

I'd like to offer a few more details regarding the new WhirlWind Propellers ground adjustable GA340 propeller. This is a 78" diameter two-blade composite propeller specifically designed for the Cub Crafter's Carbon Cub SS airplane.

The GA340 propeller allows you to adjust the propeller pitch to your preferred mission profile (aggressive short field and climb, or for quiet, efficient cruise performance or some where in-between). You have multiple mission settings all in one propeller. Efficient operation and high performance goals were in mind when we designed the long highly tapered blade shape and very thin blade cross-section along with the aggressive under cambered airfoils to achieve optimum lift distribution and maximum L/D.

GA340 Blades:
The blades of the GA340 propeller are manufactured with thermo-set carbon fiber composites, overlaid on a high density foam core. The leading edge protection is electroformed nickel which offers the best abrasion protection, especially when flying from unimproved airstrips. The blades are painted satin black with white tip striping and are finished with a durable polyurethane top coat.

GA340 Hub:
The GA340 hub assembly is 3-D CNC machined from aerospace billet aluminum. Each hub is anodized black for corrosion resistance and appearance.

GA340 Spinner:
The GA340 spinner is constructed from all carbon fiber material. The spinner is trimmed and fitted, and is ready to install and fly. The spinner is available in two different finishes: Carbon Fiber print-through gloss or optional primed and ready to paint.

Pitch Change:
The key feature of the GA340 propeller is that blade angles can be adjusted to an infinite number of settings. Propeller blade pitch change is a breeze. It's a three-step process. 1. Loosen the hub clamp bolts, 2. Rotate the blade via supplied blade pitch paddle to desired pitch setting and verified by digital protractor (not supplied). 3. Tighten and torque hub clamp bolts. The process takes about ten minutes including removing and installing the spinner dome.

GA340 propeller package includes: hub assembly, propeller blades, spinner, blade pitch paddle and all related hardware.

And.... Cub Crafters now stocks the GA-340 propeller & spinner package.

Please feel welcome to contact me with any other questions.

Sincerely,
Jim
WhirlWind Propellers
wwpc@whirlwindpropellers.com

GA340s.jpgGA340-spinner.jpgGA340-spinnerexp.jpg

[turbopilot]

Jim, what are the lowest and highest pitch settings possible with the ground adjustable prop?

[KatieB]

My significant other had a Whirl Wind constant speed composite prop on his 200-hp RV-8. From this experience, I can say that Jim's crew makes a beautiful piece of machinery. Thanks Jim and Pete for chiming in to answer questions!

[randylervold]

Hello to the Cub Crafters Forum,

I'd like to offer a few more details regarding the new WhirlWind Propellers ground adjustable GA340 propeller...

Jim, thanks for coming aboard and providing more info! Hopefully owners who install these props will report back on their experience. We have two props in stock right now and available though I think one has just been purchased.

[WhirlWind Propellers]

Jim, what are the lowest and highest pitch settings possible with the ground adjustable prop?

Hi Turbopilot,

The GA340 propeller has an infinite number of pitch settings, although there is a practical pitch setting for your chosen mission profile. For example, if the pitch is too low, you may have excellent take-off performance, but your cruise speed will be very slow in order to remain within operating cruise RPM. Conversely, if your pitch is set too high you will have excellent cruise efficiency but the take off / climb performance will suffer.

The beauty of the adjustable pitch GA340 propeller is that you can choose the pitch setting that best matches your desired mission profile.

Sincerely,
-Jim

[John Hodges]

Hey Jim, when do we get our prop back? We love it!!