Ivoprops?
 

Okay, go ahead. Burst my bubble. Ivo claims "up to 700 hp" for his Magnum prop. In-flight adjustable graphite with a CHEAP constant-speed controller option. 3 blades, 27 pounds, $2400.

I can take it. Tell me why this is "too good to be true." Ruin my day. What am I missing? What's the dirty little secret?

I fly one of these on my -6A turbo Subie. Works well, no problems. Might absorb 700hp at 4000 prop rpm. Count on 200hp at "normal" 2700 prop rpms with the 3 blade. Not recommended on Lyco engines as the power pulses have been known to shake them to bits. The C/S controller has not worked well for some people. I just toggle mine and use an ammeter to judge pitch angle.

IVO props don't have a very good history on 4 cyl, 4 stroke, direct drive engines. During my 12 year search for the best fixed pitch prop, IVO was one of the first I researched. There were several tried on RVs, several crashes caused by the prop coming apart, and at least one fatallity. My search finally ended just over a year ago when I discovered the Catto prop.

A local Lancair 200 builder had one on his O-235. I forget how many hours he had on it (less than 100) and it threw a blade. He managed to land in a soy bean field, but the airplane was a right off.

I'm with Mel. I love my Catto 3 blade.

IVO has specifically NOT recommended their props be fitted to direct drive Lyco, Conti engines for over 5 years now. Anyone who does not follow prop manufacturers recommendations is risking their aircraft and their life.

There was a design change about 6 years ago to knurled drive plates and new torquing procedures. If these are followed on recommended engines, the props appear to be very reliable. It appears that some recent failures involved people not following the torquing procedures outlined by IVO. Again do this at your own risk.

I have 193 hours on IVOs with zero problems. Takeoff and climb performance is far superior to any FP prop. My 6A has trued 181 knots with one on the top end also.

My $.02
 

A few years ago a wellington Fl. resident was killed when the Velocity he was flying (WITH his family BTW) had his IVO come apart. Violent crash.
First the facts as observed by myself...
Then, a few months after this crash, I was looking for a prop for my kitfox (bought a warp drive, but my LYC pulses, even with a harmonic balancer, tore it up.....now my new Catto is actually in transit, finally!!!! Thanks Craig !), and I went to Palm Beach Propeller at Lantana Airport in Fl., to get some used prop ideas...PBP had an actual Ivo blade, sent from Ivo himself, that was delaminating. Ivo apparently was looking for a dependable NDT process to check for delamination. This blade he sent to PBP was one that had delaminated in the middle of it's span. Now, the next day I called and spoke to Mr. Ivo himself, and guess what he said..."Nope, no crashes I know of...None have come apart...... A N D , he 100% totally denied the fact that PBP had one of his "delaminating" prop blades, since he does not have this problem ,with his props". Kind of funny, since PBP even showed me later the invoice from Ivo with his name on it.
So, now comes my IMHO.......Go ahead and put an Ivo prop on your plane, but PLEASE don't fly over my house or start your engine near me. Yet another great idea that fails lethally in application.
Glen

At the time I was researching IVO props (early to mid 90s), Mr. IVO specifically recommended his Magnun porp for RVs. He told me that there were several RVs flying with the prop and even offered me a super deal to get his props "out there". When I asked him about the RVs I had heard about throwing blades, he never again responded to my e-mails or phone calls. Just my experience.

Yes, there have been cases of IVOs failing but so have there been on pretty well every other brand out there. (check the NTSB database) When the Magnum was new, with the un-knurled plates, it was unknown how they would perform on a Lyco as little or no testing had been done to my knowledge. I say IVO should have done some testing before offering them for sale. Much initial testing was done on LOM engined RVs which obviously had different torsional vibration characteristics from a Lyco.

The knurled plates were a huge step forward but once reports of failures on direct drive engines started coming in, IVO stopped selling for these applications. As far as I know now, they WON'T sell to you for a Lyco or Conti application anymore because they just are not suited. These props were designed primarily for alternative engines with redrives and soft couplings and lower amplitude power pulses. There are a number of Wankel, Rover V8 and Sube aircraft flying successfully with them.

My experience with IVO has been very positive. They answer questions promptly and ship things quickly.

There have been some recent cases of failures where the users admitted that they did not follow IVOs recommendations on installation and torquing. Well Duh! Can't blame that on the prop any more than on a wood or Hartzell prop where people ignore manufacturers recommendations. These are airplanes, not tractors we operate.

I'd heard and read lots of bad things about IVO props from both people who had flown them and armchair "experts" before I bought mine. None of the speculation proved correct in my experience.

If you are using a Lyco, best stick with the popular brands- Hartzell, Sensenich, Catto, MT etc. If you have an auto engine with a proper redrive, the IVO is an alternative which works for many of us. I'd buy another as there is no other prop out there for $2500, which weighs 27 lbs complete that gives me the takeoff, climb and cruise performance of the IVO on my Subie installation.

Consider my bubble burst. (Bursted?)

On the plus side, I start flight training next Saturday. :D

Don't
 

I put a 3 blade, then went down to 2 blade on my Lancair 235 in 1996. Within a few hours after a routine flight I landed. Fortunately I hadn't gotten a new spinner to make the 3-2 blade change and without a spinner was able to immediately observe a crack in the front plate from one of the bolt holes to the edge. Ivo was eager to get the original plates back. Sent me knurled plates and stainless tapes to tell if the blades were moving relative to the plates. Flew it a few more hours and then quit flying it. Good decision. If you contact Ivo today they will tell you their prop is not recommended for direct drive applications. Perhaps if they used a large hub plate with multiple bolts to secure each blade they would stay together. The idea of simply twisting the blade worked like a charm. I was cruising at 185 mph on 115 hp! But remember, as soon as you mount up something as untested as this, you become a test pilot. I think they always wear shutes and fly alone.
---Dick---