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JETLAG03

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300+ flexwing (pendulaire) newly trained on gyrocopter ((autogire)100h)
Curious, if with 100hp (example) one can spin the prop to its max rpm static, at max AoA, will extra hp actually create more thrust?
 

Resasi

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Certainly a hot rod of gyros. Pretty impressive.

Reminded me of seeing Roy Davis with his little single and its rate of climb.
 

PeterFromLA

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Gee that calidus should be a rocket.

wolfy
I just realized, looking closer at the images, this is not a Calidus... This is a Kallithea from Niki Rotor Aviation...
 

Jean Claude

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Curious, if with 100hp (example) one can spin the prop to its max rpm static, at max AoA, will extra hp actually create more thrust?
More power can always give more thrust. For that it is enough to increase the pitch of the blades (to take into account the additional of induced speed), and their surface (not to reach their stall)
But there are unfortunate side effects:

- An excessive acceleration of the takeoff run may exceed the Rrrpm acceleration and produce flapping divergence

- Engine torque effects may be excessive, if the propeller blast is not "detorduced" by fins or tailplane

- A too large slope of climb decreases the load on the rotor and thus a too low Rrpm.
 

PeterFromLA

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More power can always give more thrust. For that it is enough to increase the pitch of the blades (to take into account the additional of induced speed), and their surface (not to reach their stall)
But there are unfortunate side effects:

- An excessive acceleration of the takeoff run may exceed the Rrrpm acceleration and produce flapping divergence

- Engine torque effects may be excessive, if the propeller blast is not "detorduced" by fins or tailplane

- A too large slope of climb decreases the load on the rotor and thus a too low Rrpm.
Also, taxiing becomes a problem when you have to ride the brakes even with the engine on idle...

When it comes to takeoff though, you can always take off with less than 100% power and just fly the gyro, not the checklist...
 

N962GT

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I've been building, flying and selling 145-165HP normally-aspirated, factory stock, carb & FI gyro engines that weigh 20 - 28 lbs less than the Edge turbo 912 since 2012. What's all the fuss? 10,000+ fleet hours, not a single engine-out in all of our 9 years.

My personal gyro is a 570 lb (DW) carbbed 145 HP Air Command Yamaha that I first flew November 2012, 9 years ago.
Relax.

Nuttin' to worry about, just be careful on those super-steep climbs, they require lots of rudder authority; work up to them like a race car driver works up to going 200 mph on the track, and throttle back when rolling out at the top of a climb.

Take-off and powering out of downwind turns is a dream. Once the nose comes up go full throttle and literally launch. None of this pushing the nose over and gaining AS nonsense before going climb, although when you're getting used to it it's better to continue going with that method for a while.

This Air Command tandem has a TOW of 795 lbs. with 1 hour of fuel and 200 lbs pilot w/ gear.

2021 Mohawk Aero YG4 Grass Field Take Off

 
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Doug Riley

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If you have horsepower to spare, a more wholesome way to use it is to employ a partial rotor drive, as Dick Degraw does.

The problem with putting excessive power to a propeller is that it leaves the rotor with nothing to do. That is, in a full-power climb, the prop supports a significant part of the weight of the gyro. This reduces the angle of attack of the rotor disk, much like cutting the string of a kite. The rotor responds to the lack of load* by slowing down. Then, at the top of the climb, when you again apply the gyro's full weight to it, you are risk for destructive flapping (retreating-blade stall).
__________________________________
* A rotor can't sense load directly. Instead, it reacts to disk angle of attack. When we say we "unload" a rotor, we mean that we reduce the rotor's disk angle of attack. We do that on purpose upon landing -- we push the stick forward. Some pilots refer to this as "killing" the rotor, a pretty apt term. Don't kill your rotor in flight; it just might return the favor.
 

Jean Claude

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I piloted gliders C800, Bijave, C 310, airplanes Piper J3 , PA 28, Jodel D117, DR 220, Cessna 150, C
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About 500 h (FW + ultra light)
My personal gyro is a 570 lb (DW) carbbed 145 HP Air Command Yamaha that I first flew November 2012, 9 years ago.
Relax.
Yes, but this video shows 18 seconds of run before the T.O. The maximum thrust of 145 Hp is clearly not used in this phase.
 

WaspAir

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Most of my gyro time is courtesy of 180 hp Lycomings with the extra low end muscle applied to 125% pre-spins or to jumps. If you put 1800 or 18000 hp on an A&S18A or J-2, you could carry some more weight and get a higher ceiling but you couldn't go any faster. Vne isn't from a power limitation.
 

wolfy

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I've been building, flying and selling 145-165HP normally-aspirated, factory stock, carb & FI gyro engines that weigh 20 - 28 lbs less than the Edge turbo 912 since 2012. What's all the fuss? 10,000+ fleet hours, not a single engine-out in all of our 9 years.

My personal gyro is a 570 lb (DW) carbbed 145 HP Air Command Yamaha that I first flew November 2012, 9 years ago.
Relax.

Nuttin' to worry about, just be careful on those super-steep climbs, they require lots of rudder authority; work up to them like a race car driver works up to going 200 mph on the track, and throttle back when rolling out at the top of a climb.

Take-off and powering out of downwind turns is a dream. Once the nose comes up go full throttle and literally launch. None of this pushing the nose over and gaining AS nonsense before going climb, although when you're getting used to it it's better to continue going with that method for a while.

This Air Command tandem has a TOW of 795 lbs. with 1 hour of fuel and 200 lbs pilot w/ gear.

2021 Mohawk Aero YG4 Grass Field Take Off

Quite a difference between 145 and 300 hp wouldn't you say, that's if it actually is making 300 hp.

wolfy
 

Abid

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If you have horsepower to spare, a more wholesome way to use it is to employ a partial rotor drive, as Dick Degraw does.

The problem with putting excessive power to a propeller is that it leaves the rotor with nothing to do. That is, in a full-power climb, the prop supports a significant part of the weight of the gyro. This reduces the angle of attack of the rotor disk, much like cutting the string of a kite. The rotor responds to the lack of load* by slowing down. Then, at the top of the climb, when you again apply the gyro's full weight to it, you are risk for destructive flapping (retreating-blade stall).
__________________________________
* A rotor can't sense load directly. Instead, it reacts to disk angle of attack. When we say we "unload" a rotor, we mean that we reduce the rotor's disk angle of attack. We do that on purpose upon landing -- we push the stick forward. Some pilots refer to this as "killing" the rotor, a pretty apt term. Don't kill your rotor in flight; it just might return the favor.

Yes you can unload the rotor with lightly loaded high performance machine using full power on the prop but the power is in your hands. If you have a conceptual understanding of the fundamentals its a fairly simple thing to handle. If you don't have fundamentals right, you will get yourself in trouble.

I recently flew with a IFR airplane pilot with thousands of hours in GA airplanes who used the stick to control "altitude" leaving the power set to where it was. Airspeed be damned. I would like to know who has been signing him off on his flight reviews all these years. In a rotorcraft, that could be a killer. In airplanes its pathetic technique and sloppy arse flying that needs a whopping from a CFI. You can read all the plates you want and know how to do GPS approaches. If your fundamentals are backwards, your experience is simply doing the wrong thing 20,000 times.
 

All_In

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Not sure over 10,000+ logged FW, 260+ ultralights, sailplane, hang-gliders
Quite a difference between 145 and 300 hp wouldn't you say, that's if it actually is making 300 hp.

wolfy
Takeoff and Fly it at 1/2 throttle?🤣 So not sure why you need it she cannot fly past VNE.

I hope it has a huge rudder because the Cavalon with only a 140HP you hit the right rudder stop with full power. Huge, huge, rudders, or drop the HS on the right by what about a foot??
 
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All_In

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Not sure over 10,000+ logged FW, 260+ ultralights, sailplane, hang-gliders
The Cavalon 915 I do not take off with full power or she will jump up, not balance on the mains, and fly off.
For my weight and low-density altitudes, I've not needed full power for any maneuver,
Full power for me is about 75% unless I needed to climb over an obstacle then it will be nice to climb 1500 feet a minute or take off at 10K.
 
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JETLAG03

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Location
france
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300+ flexwing (pendulaire) newly trained on gyrocopter ((autogire)100h)
My original question phrased differently. (#7)

The prop is already at the MAX AoA permissible by the manufacturer.

At this setting 100hp, is sufficient to spin the prop at the maximum rpm (static) permitted by the manufacturer.

In this situation, unable to increase the AoA or spin the prop faster would 300hp change the thrust available or simply mean the engine does not need to create full power.
 
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