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

WaspAir

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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.
 

Inquiring Mind

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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?
 

WaspAir

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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.
 

fara

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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.
 

WaspAir

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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.
 

fara

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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.
 

WaspAir

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. 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.
 

Inquiring Mind

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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.
 
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