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electrical in-flight adjustable prop


tdale4

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No.

Do a search on IVO in the NTSG reports and you'll find out why.

A lot of the stuff is fairly old. Perhaps they've improved. I won't be the one to find out. One of the stories - a Velocity that crashed (3 on board killed) was from my airport. Admittedly this guy did a lot wrong, but...

The ACRE list has been pretty negative about them on a structural standpoint.

I can be reached on the "other" forum http://canardaviationforum.dmt.net

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Are there any alternativies to IVO? or are you going to use a fixed prop? If fixed, are most cozy drivers choosing to use a cruise prop to get the high cruise speeds and is this why the take off/landing distances are twice that of an RV 10? I'm sold on the cozy, i'll be ordering my plans next week along with chapters 4-7. I know it will be a few years before I need to worry about this but I do want a plan/budget to follow. incidently I will be building in my garage, It's about 19'x18' will this be big enough? I'm hoping I can wait to attach the wings untill the end.

 

Thanks,

Tim

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Hi tdale4,

To my knowledge there are no alternatives to the IVO prop.

I've never seen an IVO, but from hearing the horror stories I would be very careful. Looking at the diagram of it's design, it looked to me that there was too much to go wrong.

 

Am I right that the one that crashed wasn't bolted together properly?

 

Dust is the only person here with a constant speed prop, I think. It might be possible to convert a Lyco Continental unit csu to run on a rotary, but it would involve some very serious engineering.

 

Most people, if not all excepting dust, choose the fixed pitch prop. The rotary or another high revving engine will require a reduction gearbox, unless you wish to try the ducted fan direct drive, of which there is one flying on a Long EZ, and another here planning the same.

 

The cruise prop is used as this is what the Cozy is designed for, a climb prop would somewhat defy the point. The Cozy, and canards in general take longer to take off because of a) as you said they have a cruise prop, and b) the canard needs to fly off the runway, whereas a conventional tail plane is forced downwards, increasing the Angle of attack of the main wing, and thus rotating earlier.

Rutan's stall proof design decides the size of the canard, and thus they rotate later.:D

 

Cheers

Adam

The Coconut King

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>stall proof design decides the size of the canard, and thus they rotate later

Not necessarily. Take off distance is a function of acceleration. When you get to flying speed you fly. Greg Richter (turbo 13B cozy III) told me a little story when I visited him. He'd flown his own plane a few time and said that when you opened the throttle you got a push in the back like you were flooring the gas in a Porche. He had someone standing by the runway, and his take off run was VERY short.

 

After 2 or 3 flights he decided he'd like to get some dual, so he found a nearby 360 Lycoming powered Cozy IV and an instructor and went flying. He opened the throttle on his first take off roll. Part way down the runway he throttled back and aborted the take off. The instructor asked "what's wrong". Greg felt there was something wrong with the engine. "Nope", said the instructor. "Its running perfectly". The point is that the difference in acceleration between the two planes was so dramatic that Gregs first reaction was that the Lycoming wasnt going to fly.

 

Greg is a member here, but he's probably too busy with http://BlueMountainAvionics.com and his new jet turbine installation to spend much time chatting. As they say - there are those that do, and those that talk. Right now I'm just talking. If I got the story wrong, I hope he'll correct me. MT - I know you chatted with Greg. Did you discuss his take off performance?

 

Recently I heard that Hartzell had announced that their $15k constant speed prop had problems at certain rpms on Velocities. Again, someone can fill in the details.

 

Yes, if you read the NTSB report, which I did recently, you'll see that the Velocity IVO pilot had a prop problem, landed, stripped it down and reassembled it himself, failed to torque it properly and then set off again (with his two daughters) without following the prescribed tests, for an appointment with a tree.

 

My thoughts on the prop was to go for max cruise speed 3 blade wood prop. My prop was designed for 280HP and 250mph cruise on the basis that it can easily be cut back, but cannot be tweaked up. I think I'll have enough spare power to take off in a much shorter distance than a stock Cozy, and climb faster even though my prop is not optimum for those flight areas.

 

Unfortunately, extra horses on board dont help you land any shorter :mad:, so you still need a long runway to operate from.

I can be reached on the "other" forum http://canardaviationforum.dmt.net

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Feeling pretty nervous making repeat appearances in the Rotary section. But just to climb on my high horse called "Pedant", to argue about the toss, split some hairs, etc etc.

1. Throwing apples and oranges to the masses, I'd say that if you put a 280 hp turbo nutter rotary in the Cessna 172 beast, it would perform something akin to a helicopter.

2. If I snuck into Greg's hanger and amputated 6'inches off either side of his canard he would rotate later.

3. If I snuck back the next day and added 4 feet to the canard, then it would rotate sooner, yet you would be facing the possibility of a deep stall and death.

:D

The Coconut King

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  • 3 months later...

...hhhmmmmm....

 

I did a quick search on the NTSB database for IVO prop and found only 4 reports between 1/1/89 and 5/18/2004. 3 were engine failure and one was a Darwin award to the pilot. None were prop failures. I've been seriously considering thte IVO prop but now you've got me worried :scared:

 

I think it was Socrates who came up with the three point plan for passing on rumors 1) do you know it to be the truth? 2)is it derogatory? 3) does it benifit me to know?

 

Can anyone point me to some facts about the IVO prop? :confused:

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  • 3 years later...

Take a look at this website: http://www.silence-aircraft.de/

 

Unfortunately it is a flash website so I can't get the exact hyperlink for the V prop page, but click on the US flag on the top right to get english and then on the "Propeller" tab.

 

It seems a pretty neat prop. It has a spinner with vanes that generates sufficient power to drive the electronics without needing slip rings. It is fully automatic and can be programmed by jumpers (bridges on the circuit board). It defaults to fine pitch for safe landing or takeoff if the electonics take a dive. And it costs a mere 3600 Euro. Compare that to an MT prop... That is of course the only certified option for any long derivative, tested extensively by the round the world fliers (one swiss air pilot has done it 3 times in his long).

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...hhhmmmmm....

 

I did a quick search on the NTSB database for IVO prop and found only 4 reports between 1/1/89 and 5/18/2004. 3 were engine failure and one was a Darwin award to the pilot. None were prop failures. I've been seriously considering thte IVO prop but now you've got me worried :scared:

 

I think it was Socrates who came up with the three point plan for passing on rumors 1) do you know it to be the truth? 2)is it derogatory? 3) does it benifit me to know?

 

Can anyone point me to some facts about the IVO prop? :confused:

I just have to wonder if the IVO prop company has anything to say. Sure a person should use caution with any information provided by stakeholders on that side of the fence, but they would probably have some insight into incidents involving there products.

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It seems a pretty neat prop. It has a spinner with vanes that generates sufficient power to drive the electronics without needing slip rings.

I saw a similar mechanical prop powered directly by airflow at an airshow once, and the same concept is on the elderly Pilatus P2. Not sure that either of them would work when it is the last thing through the airflow of a pusher, rather than the first. Then engines it is designed for look a bit puny also.

 

http://photos.linternaute.com/photo/1093405/1019196287/1686/pilatus-p2-06/

Mark Spedding - Spodman
Darraweit Guim - Australia
Cozy IV #1331 -  Chapter 09
www.mykitlog.com/Spodman
www.sites.google.com/site/thespodplane/the-spodplane

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Originally Posted by rhofacker

...hhhmmmmm....

 

I did a quick search on the NTSB database for IVO prop and found only 4 reports between 1/1/89 and 5/18/2004. 3 were engine failure and one was a Darwin award to the pilot. None were prop failures. I've been seriously considering thte IVO prop but now you've got me worried

 

I think it was Socrates who came up with the three point plan for passing on rumors 1) do you know it to be the truth? 2)is it derogatory? 3) does it benifit me to know?

 

Can anyone point me to some facts about the IVO prop?

 

 

I just have to wonder if the IVO prop company has anything to say. Sure a person should use caution with any information provided by stakeholders on that side of the fence, but they would probably have some insight into incidents involving there products.

 

Just so you guys are up to date, John Slade is now running an IVO, inflight adjustable prop. At the time of these origianal posts, 2004, most of us didn't know not to use IVO props on big 4 cyl airplane engines (destructive power pulses). John's rotary engine and psru seem to do well with the IVO. We''ve all learned alot, and with the right engine, IVO props seem to be a very nice alternative.

Andrew Anunson

I work underground and I play in the sky... no problem

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/http://www.variprop.com/

That sure is a nice looking alternative. Does anyone understand the idea of how it works? I can't understand where the energy to change the blade settings comes from. They mention that it can handle powerful direct drive engines... it sounds like they are going after the direct drive portion of the market which IVO won't sell to. It would be nice to see a few in operation.

Andrew Anunson

I work underground and I play in the sky... no problem

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Pitch change is done be a small electric motor inside the hub. I have a MT that is also an "electric" pitch control.

 

IVO will sell to direct drive, but NOT pusher direct drive.

 

Waiter

F16 performance on a Piper Cub budget

LongEZ, 160hp, MT CS Prop, Downdraft cooling, Full retract

visit: www.iflyez.com

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Pitch change is done be a small electric motor inside the hub.

That is true with the IVO, but the variprop webpages mention hydraulically actuated. Lots of talk of how their system is better than electrically actuated, becuse the wires and brushes are eliminated.

 

I would like to know how it "works".... so I'll send them an email and let you know what they say.

Andrew Anunson

I work underground and I play in the sky... no problem

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That sure is a nice looking alternative. Does anyone understand the idea of how it works? I can't understand where the energy to change the blade settings comes from. They mention that it can handle powerful direct drive engines... it sounds like they are going after the direct drive portion of the market which IVO won't sell to. It would be nice to see a few in operation.

 

I believe that the Vari-prop has a hydraulic cylinder, similar to a master cylinder in the cockpit which supplies the pressure to set the blade angle.

I Canardly contain myself!

Rich :D

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OK... thats how a throw-out bearing operates in manual transmissions in cars. My first car had a hydraulic clutch master cylinder which hydraulically activated a slave cylinder mounted on the transmission housing. The slave cylinder activated a forked lever the made the throwout bearing slide on the transmission shaft. The bearing would move the clutch plates somehow. That makes sense to me, and throw out bearings last long enough. They have a TBO of 1000 hours, and if a throwout bearing is in fact their design, then it could be a replacement item.

Andrew Anunson

I work underground and I play in the sky... no problem

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Hydraulic Control generally refers to a high pressure oil pump and speed governor that are mounted on the accessory case of the engine, Commonly refered to as the "Prop Governor"

 

High pressure engine oil is then routed from the governor, to a fitting on the nose of the engine, where its routed to the #1 main bearing, through #1 main bearing and into the center of the crankshaft. The Prop Hub has a piston thats operated by this pressure to rotate the blades.

 

This is probably the most common method of controlling props on GA aircraft.

 

Waiter

F16 performance on a Piper Cub budget

LongEZ, 160hp, MT CS Prop, Downdraft cooling, Full retract

visit: www.iflyez.com

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This is probably the most common method of controlling props on GA aircraft.

Yeah, but not the Vari-Prop, because they claim that you don't need a hollow crank to use it. I had dinner with the company owner at Copperstate and saw the hardware in the car on the way to the restaurant, but we talked more about the business model and development rather than the technical aspects of the design.
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http://www.silence-aircraft.de/...Compare that to an MT prop... That is of course the only certified option for any long derivative...

First of all, the prop you refer to is only for engines up to 80 HP - barely adequate for a VE if at all, and certainly not for a LE or COZY.

 

Secondly, There is at least one other MFG of certificated propellers that has sold units to canard flyers (Hoffman), although the prop is no longer on the plane.

 

But the certificated nature of the propeller is meaningless, since it's an engine/prop/airframe combination that's certificated, and that clearly isn't the case when using any propeller on a Rutan derivative canard aircraft. What's important is whether it's been tested and works, not the paperwork.

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Hey Marc, I talked to Larry of VariProp and he didn't have any info on people flying any of his props yet. He said lots are sold, and a VariEzE has one being installed real soon, but no feedback. I think the machinery really looks substatial...quality stuff. What is your view on it?

One remark he made was it is all built to FAA standards and requirements. It uses a hydraulic slave cylinder in the prop and a master cylinder mounted anywhere else one cares to, in the aircraft. It has a standard dial control on the I.P for feathering that enters the amount into a small computer which regulates the hydraulics and blades. Weight is 39# at the prop. [Whats a MT weigh?] The VP2 was built using a IO360 with high compression pistons, and he says, "If it can withstand that kind of vibration- it'll work on anything". Out the door price is 7995.00.

It sounds interesting. MT's are about 14 grand. Yow!

Self confessed Wingnut.

Now think about it...wouldn't you rather LIVE your life, rather than watch someone else's, on Reality T.V.?

Get up off that couch!!! =)

 

Progress; Fuselage on all three, with outside and inside nearly complete. 8 inch extended nose. FHC done. Canard finished. ERacer wings done with blended winglets. IO540 starting rebuild. Mounting Spar. Starting strake ribs.

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Hey Marc, I talked to Larry of VariProp and he didn't have any info on people flying any of his props yet. He said lots are sold, and a VariEzE has one being installed real soon, but no feedback. I think the machinery really looks substatial...quality stuff. What is your view on it?

One remark he made was it is all built to FAA standards and requirements. It uses a hydraulic slave cylinder in the prop and a master cylinder mounted anywhere else one cares to, in the aircraft. It has a standard dial control on the I.P for feathering that enters the amount into a small computer which regulates the hydraulics and blades. Weight is 39# at the prop. [Whats a MT weigh?] The VP2 was built using a IO360 with high compression pistons, and he says, "If it can withstand that kind of vibration- it'll work on anything". Out the door price is 7995.00.

It sounds interesting. MT's are about 14 grand. Yow!

 

Unless the company was sold, etc, something does not sound correct.

 

this prop has been around for at least about 20 years in one form or another. Perhaps he is talking about the higher HP models.

I Canardly contain myself!

Rich :D

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...What is your view on it?

I was impressed with what I saw, and I was impressed with the man from spending an hour or two with him. However, without a bunch of them flying and a lot of hours on them.... I wish them success, and hope they make it, for sure.
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