5 Things to Know Before Buying ground adjustable pitch propeller

Are you ready to purchase a replacement propeller for your aircraft, or do you know someone who’s just getting into aviation who’s looking for their first? Here are some tips from us about what you should know before purchasing a propeller:

Click here to get more.

Rayi supply professional and honest service.

If you want to learn more, please visit our website ground adjustable pitch propeller.

1. Understand the advantages of different types of propellers for your aircraft. Do you want to reduce noise? Improve performance? For instance, the Hartzell scimitar blade with a back-swept wingtip, can reduce noise and may improve efficiency over a regular blade.
2. Know the differences between a propeller that needs to be replaced and a propeller that requires adjustment. Here are three factors to consider when you’re looking into propeller replacement. Replacing a propeller is a big investment, so be sure to have your prop looked at to ensure that any concerns you have about performance can be fixed with an overhaul or routine adjustment.
3. If you choose a fixed-pitch propeller, it will need to be re-pitched. We already detailed the differences between fixed-pitch and variable pitch But did you know that if you choose a fixed-pitch propeller there is a limit to the cumulative amount the blade can be bent? If you’re buying a used propeller blade, this is especially important, as it may have been bent out.
4. More propeller blades aren’t always better. While 2-blade propellers may be more efficient, it’s thrust that propels an airplane. As power increases, additional blades may be required to efficiently use the increased power. Check your manual to determine the optimum numbers of blades for your aircraft.
5. Choose your propeller blade material carefully. There are generally three types of propeller blade materials in use today: wood, metal (generally aluminum alloys) and composite. At Hartzell, our propeller blades are made from high strength aluminum alloy forgings or advanced composite materials (Kevlar® or carbon fiber). Each kind of material has its advantages and disadvantages, so be sure to research the differences.
6. Experimental aircraft don’t need experimental props! When choosing the right propeller for an experimental or home build aircraft, safety, performance, weight, cost, noise, diameter limits and durability are going to be big factors for you in making your choice. For most popular kit aircraft, Hartzell has developed propellers specifically for those aircraft and they are available directly from the kit manufacturer. If you have an experimental aircraft, contact us to speak to one of our technical specialists about your needs.
7. Yes, the right propeller can increase your cruise speed – so choose wisely. However, note that it does require a large increase in propeller efficiency to produce even a small increase in aircraft cruise speed. If your prior propeller was already well-matched to the engine and aircraft performance on installation, you may not be able to push efficiency much more. However, we’ve also seen measurable speed gains in some new installations, so check with your TC/STC holder to check on accurate performance tests conducted on your specific installation.

I had an early () C76AF, GA composite Sensenich that got installed and tested on my (essentially a) PA-18-95 experimental.

There were some growing pains as the early Blade alignment pins were not clocked properly but it was small hurtles that they overcame.

The prop itself was phenomenal as compared to a metal prop. Personally I think these props make a much larger difference on small horsepower engines, or perhaps aircraft with a lower HP-to-Weight ratio.
The ultra low swing rate would set me back in the seat on takeoff due to the near instant spool up time and the aggressiveness of the blade bite would just launch me. It would make me smile every time.

Sensenich composite props are measured for angle a bit differently than others so it’s hard to compare one prop number to another without actually trying it. But, due to the flex and ability to design a composite blade different than metal, the blades were very effective at getting you off the ground and picking up cruise speed.
The biggest hurtle I had on that setup was oil temp, which I attributed to the round blade root that transitions from a wide hub out into the airfoil.
But, I also feel there was more to it than that.
In my armchair engineer perspective my opinion is that the composite allows a design that will stay loaded longer through the speed range, effectively more efficient at always providing thrust at all speeds. I noticed it more when I tested an over-propped Cato but in level flight at a constant rpm, after a bit of setting time, the plane would literally step ahead a notch and pick up a few miles an hour, as if the blades relaxed out into a cruise position. I’m a firm believer that the pitch changes on a composite prop throughout the speed range.
Back to the oil - because it’s working all the time, and the blade airfoil was not compressing air into the cowl, I had to look for better cooling methods. The last thing I tried, and it was working, was a complete new lower cowl design with a larger low pressure area to help excavate the heat.
So after this C76AF on the C90, they were kind enough to make me a bigger version for an O-290. It was a 2F0K6C76AF and worked equally as well, but the wag aero airframe was draggier and the 290 in my opinion is an engine that markets more hp than it really has.
Similar temp issues but on the 290 I had mixture control and could feed it more fuel to help cooling.

Can’t say enough good about the prop design from a fly-ability perspective. I’d buy another one today if I was flying a small continental.









Transmitted from my FlightPhone on fingers… [emoji849]

Attachments

• IMG_.webp
• IMG_.webp
• IMG_.webp
• IMG_.webp
• IMG_.webp
• IMG_.webp