NR and Catto prop in a video.

[napierm]

https://www.youtube.com/watch?v=c-yV9BKUmJ8&t=741s

Watched this video and looking at an adjustable pitch Catto prop. Didn't know there was one. Nothing about it on the Catto web site.

He also mentioned that there was a Kitfox that lost a blade from an NR prop and it resulted in a fatality. I don't see it on the NTSB site.

[avidflyer]

I think Trent could have mentioned that the lost prop blade was on an O-320, not a Rotax. And it seems like he has had great service from his NR prop till this point. This accident was reported on this site a couple of months ago. I'm not finding it now though. JImChuk

[Eric Page]

This accident was reported on this site a couple of months ago. I'm not finding it now though.

The thread you're looking for is here, and the NTSB preliminary report is here.

[Shadowrider]

I am skeptical that we will hear anything from the ntsb on this accident but maybe? We run two NR props on our edge 160hp engines. They have been great props and pull hard and we have almost 500 hours on one and 300 hours on the other. Wish we could figure out more to what happened. I sent Roman, the manufacturer, an email and in his response didn’t give me much confidence in the investigation. I forwarded him the preliminary and this is part of his response.

“Hello Dustin !




Yes, they contacted me. Although they gave me less information than the document you sent.


I didn't know that they found plexiglass from the plane's cabin.
We had no cases of blades flying off. From the photo they gave me. The butt part of the blade is crushed from the rear and the blade is opened along the trailing edge. It seems like the engine suddenly stopped and a catastrophe occurred. But that's my opinion. And from your document I understand that they found an ipat and broken glass, I immediately have questions...


Best regards Roman”


Another thing I did find is that there is a history of blade failures on this engine. Vans aircraft have had a couple blade failures similar to this so maybe harmonics? Also I can see if the hub was over torqued and accidentally crushed the blades? The NR hub we have squeezes the props. Torque is not very much to hold the blades, so I could see that as a possibility? If there is a lighter and better performing prop I am interested. Biggest complaint I have about the NR props is the spinners, so I am in the process of making a new carbon one.

After watching Trent’s video it got me thinking about prop balancing. I am amazed at how many people fly without balancing props. When I ask I usually get the same response, “it runs very smooth with very little vibration”, or “it was balanced at the factory.” Not saying the failure is related, but why not balance your props? If you want to smooth out and reduce vibration get your prop balanced. When you balance them make sure to balance with the spinner on. Also once you balance your prop just know it’s not going to stay balanced. I know there are some haters, but at the least put a balance master on. I balanced my prop and then put a balance master and saw improvement in the lower rpm’s. Every person who has put a balance master on has told me thanks it makes a big improvement.

[bbs428]

Great info Dustin. Glad you got hold of Roman.

Agreed on the harmonics and its possible there was a torquing issue, although that's just conjecture at this point.

I called Hal Stockman on this topic as he has well over 1000 hrs. on the NR prop's, and he's never had an issue.

I have about 53 hrs. on my NR propeller (SR 106) and pulled a conditional inspection on the hub and blades to be safe. It still looks new with no issues noted.

[airlina]

Back in 1999 when I ordered my Series 5 kit from skystar the biggest factory supported engine was the Continental IO-240, so that is what I went with. The factory demonstrator "Outback" had this engine configured with a 3 blade warp drive that i flew on a demo flight in Idaho. Bought the kit ,started to build and a short time into my build , got a critical service bulletion that this engine/ prop combo was not working and the warp props were cracking at the hub. The prop was still hanging on my shop wall so back it went for a full refund, and I switched to a good old fashioned Sensenich wood prop that has served me well for over 1000 hrs and over 20 years. Of course as a typical homebuilder , every time I was at OSH and saw all these new ground adjustable composite props being offerred I thought I need one of those. Not so fast hotshot, my research would show that the Contintental IO-240 engine has what they call high power pulses and is known as a prop eater. When talking with the sales folks at each prop manufacturer and I said the prop was for my IO-240 , I would get a grimace . Some would say , sure we'll sell you a prop..... but you get no warranty with it. Last time I was at OSH and talked with the head sales guy at a popular manufacturer and asked if he had any props on an IO-240 , he said yes , they recently had a Kitox guy try one.... then added "but it was cracking at the hub" and they had built him a new beefier new one that he was trying. I thanked him for his honesty and walked away. So my whole point of this story is this: As the final component that eventually puts your engine output to good use , the prop has to be bullet proof and your due diligence on your installation has to be well researched and proven . A failure, as we have seen is usually catastrophic . I have finally come to the conclusion that my ole wood prop is just fine as one of the attributes of wood is its ability to absorb the power pulses from my IO-240 and its survived the test of time. Lets be careful out there. Bruce N199CL

[patrick.hvac]

I'm cautiously optimistic. Been waiting for this Catto to come out for a while. Not sure when the Rotax setup will be publicly available, they only just started making the rotax hub a couple weeks ago I think.
The E-prop IFA looks great too, but it has an IFA price tag. The Catto is typically on the high end of fixed props ($ and quality).
Curious to see how this shakes out. I hope they don't want IFA money for a ground adjustable.

[Redline]

Also check out the Sensenich ground adjustable. Well built, priced between the NR and Catto and great product support from the factory.

[alexM]

I saw a Kitplanes article just recently with a list of prop manufacturers.
The only prop from Ukraine was Kiev. I noticed that it said they were ONLY for engines with a gear reduction unit.
It didn't say why, but I suspect it's harmonics.

[airlina]

Apparently direct drive engines are more suseptible to having the engine's power pulses transmitted to the prop , and engines with gear reduction units are less likely to have this problem. Bruce N199CL