Constant speed prop on a gyro, anyone care to share the experience?

Because it makes the aircraft ineligible for operation by those with only Sport Pilot privileges, and that seems to be the target market. Otherwise, they're great to have.
 
Because it makes the aircraft ineligible for operation by those with only Sport Pilot privileges, and that seems to be the target market. Otherwise, they're great to have.
Yeah, I know, but why don't they offer it as an option for PPL holders buyers?
 
That's a business decision, not a technical one, I imagine. Maybe Fara can answer about his company thinking (I don't know if he offers such an option or not). It has been my impression that some of the European manufacturers may offer that option within Europe.
 
We do do in flight adjustable props if customers want it. I have done 3. Air Master with Whirlwind blades from New Zealand, Ivo Magnum. They add about 20 pounds total. They increase the top end speed by probably 9 mph. Is it worth it? AirMaster is $7500 more. Ivo is $2500 more installed. Both achieve the same results. If I were doing it I’d go for Ivo. The price difference isn’t worth it. Ivo does not have a good interface. No pre determined Takeoff, Climb, Cruise settings but if you learn to use it it works just fine. We do not use the circuit breaker they provide. It’s too big and burns out their motors before it engages.
It may be worth it for 915iS but certainly does not make such a huge difference in 912 or 914 that I would say it’s worth giving up 90% of resale market which is to Sport Pilots.
 
On the old Lycoming-powered McCulloch J-2, the three blade metal Hartzel constant speed compared to the 2 blade wooden Sensinich fixed pitch offered a significant increase in ceiling, gross weight, and climb rate, while reducing cruise vibration and slightly helping fuel consumption. All of the 18As came with a constant speed prop, although some were two-blade and some three.
 
On the old Lycoming-powered McCulloch J-2, the three blade metal Hartzel constant speed compared to the 2 blade wooden Sensinich fixed pitch offered a significant increase in ceiling, gross weight, and climb rate, while reducing cruise vibration and slightly helping fuel consumption. All of the 18As came with a constant speed prop, although some were two-blade and some three.

From what I have heard from some people who flew J-2, it was a marginal performer so it may have benefitted more with an adjustable or constant speed prop. I do not think vibration in the prop should have anything to do with if pitch is adjustable in flight. I have to honest and say I have not tested service ceiling with adjustable props and compared it to fixed pitch prop. I would guess it would be better with adjustable prop. But climb performance and cruise performance is simply better because you can grab full power and best of torque curve in cruise both. You can get full power with a ground adjustable prop as well unless you have a non-linear torque curve like with 915iS if you set your prop to be a climb prop. It just means you accept a compromise in cruise. Or you can pitch more towards cruise and not get full power for climb. Usually settling in the middle and getting decent climb and decent cruise. But from what I have seen you cannot expect much more than 5-7% increase on top end speed and similar increase in climb rate over a properly adjusted ground adjustable prop on Rotax 9xx series engines.
 
. I do not think vibration in the prop should have anything to do with if pitch is adjustable in flight.
The prop wasn't an additional vibration source, but running at 2350 rpm instead of 2650 rpm made everything quieter and smoother with a less "buzzy" feel. The O-360 is much calmer if you slow it down a bit.
 
But from what I have seen you cannot expect much more than 5-7% increase on top end speed and similar increase in climb rate over a properly adjusted ground adjustable prop on Rotax 9xx series engines.

That's what I wanted to know. Thanks, Fara.
 
Apologies for bumping a 5-month-old thread but I disagree with Abid on this one. He is in Florida so he only flies at really low altitudes (probably never even gets to 1000'), but the thinner the air gets, the more critical a CS prop becomes. I initially had a ground-adjustable prop and replacing it with a DUC (French) CS prop and it made an enormous difference. (I only have a Rotax 912.)
 
Apologies for bumping a 5-month-old thread but I disagree with Abid on this one. He is in Florida so he only flies at really low altitudes (probably never even gets to 1000'), but the thinner the air gets, the more critical a CS prop becomes. I initially had a ground-adjustable prop and replacing it with a DUC (French) CS prop and it made an enormous difference. (I only have a Rotax 912.)


That is true if you are starting low altitude and going to 10000 feet in the same flight. Adjustable prop will make a difference. However, most people aren’t doing that. They are sticking around the same altitude and whether you are at sea level like in Florida or at 6000 feet in Colorado. Once you adjust the prop for your condition the advantage is as I listed.
 
Apologies for bumping a 5-month-old thread but I disagree with Abid on this one. He is in Florida so he only flies at really low altitudes (probably never even gets to 1000'), but the thinner the air gets, the more critical a CS prop becomes. I initially had a ground-adjustable prop and replacing it with a DUC (French) CS prop and it made an enormous difference. (I only have a Rotax 912.)

May be as you say, but I can't see the reason.
After all, a CS prop is a variable-pitch propeller with automatic regulation. It may be fine for shorter takeoffs and also better cruise efficiency, but I don't understand why should it be better than a properly pitched ground-adjustable prop for 'thin air' flight, if your engine is not supercharged...
 
I had an old NSI electric, pitch-variable prop on my Kitfox a few years ago. It was NOT constant-speed, but pitch adjustable by the pilot.
Manually set for fine pitch for takeoff (much quicker acceleration) and then manually adjusted for coarse pitch in cruise.
Fuel flow dropped into the high 3 GPH range at 100 mph on the 912.
We later went to a ground-adjustable fixed pitch prop after a partner bounced the NSI off of the runway; the fixed pitch was a compromised setting, it was slower to accelerate, lost 10 mph or so of top speed and fuel consumption went up to 4+ GPH at the reduced cruise speed.
Sorry, don't know the weight difference, but the NSI was not all that heavy for the big performance boost.
 
Many of my flights start near sea level and involve climbing to around 6000' feet because there are lots of mountains. But even when not doing that, it made a big difference. As Smack said, either I could get an OK (but reduced) cruising speed with a coarse setting, but terrible take-off performance even when solo, or I could adjust it for better take-off when bringing a passenger but then we're really slow.

If you fly over largely flat areas, especially if you have the 914, then it's not crucial. But in the western half of the US it is very beneficial.
 
As Ed said things are different in the west.

On my recent flight to El Mirage Dry Lake from Santa Maria I left at 250 feet MSL and climbed to 5,500 feet MSL which at 90 degrees F was around 8,500 feet density altitude.

It was a good lesson for my client because it is easy to underestimate the effect density altitude has on performance.

We were operating very near maximum takeoff weight of 1,400 pounds with a normally aspirated 160 horsepower IO-320 Lycoming.

We went from climbing out at 700 feet per minute at SMX to 200 feet per minute as we cleared the pass to the high desert.

The constant speed propeller on The Sport Copter II I was flying recently made quite a difference on our climb performance.
 
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I don't doubt that –in general terms– a variable-pitch prop is much better than a fixed-pitch one, because the fixed pitch is always a compromise between the fine pitch for take-off and the coarse pitch for cruise. For a FW, the difference between the speed at takeoff and the cruise speed may be large, and so there will be an important difference between the optimal takeoff pitch and the optimal cruise pitch. But with a gyro, the difference is relatively small...

Perhaps there's one, but I don't understand the superiority of a variable-pitch prop for low air densities, for flying in 'thin air'... Of course, for any given airspeed, air density, prop diameter, prop revs and thrust sure there is an optimal pitch, that is probably much bigger than the optimal takeoff pitch, but you can always set that pitch in a simpler, ground adjustable prop. Yes, with that pitch, the takeoff run will be longer, but not too much...
 
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