Modification of Cozy with 3LS

[gontek]

I really like the canard configuration but what I really want is a 3LS, like a 4 seat version of the Piaggio P.180 Avanti. I am not really sure but I don't think it's been done before.

 

Here's what my research has turned up:

http://forums.x-plane.org/lofiversion/index.php?t24139.html

This one almost hits it on the head. Think Avanti with Adam twin booms and Cozy/EZ pusher configuration.

 

http://en.wikipedia.org/wiki/Aceair_AERIKS_200

 

http://www.kiwiaircraftimages.com/eagle.html

 

And of course check out the Avanti.

 

I imagine a 3LS would have a lot of the desirable characteristics of the Cozy for instance the handling would be improved and takeoff run decreased.

 

Has anyone seen anything like this, and how much time and money should I spend on this idea. I have lots of time and very little money I'd like to design it in my free time - I have an aero engineering degree but have a lot to learn about composites and experimental homebuilding. Actually one of my professors designed the avanti!

[Jon Matcho]

Has anyone seen anything like this...

None other than those you've mentioned.

 

...and how much time and money should I spend on this idea.

"Should"? You would need to spend all of it.

 

I have lots of time and very little money

Hmmm... time can be converted into money.

 

I'd like to design it in my free time - I have an aero engineering degree but have a lot to learn about composites and experimental homebuilding. Actually one of my professors designed the avanti!

Connect/reconnect w/your professor and ask him directly about the idea. It could definitely be done -- look at the Aeriks (although not a financial success). Also, don't worry about the composites part (unless you mean about the strength of materials, which would then be a concern for a new design).

 

All considered, a LOT of work. Good luck!

[csteiner]

I really like the canard configuration but what I really want is a 3LS, like a 4 seat version of the Piaggio P.180 Avanti.

Here is another one http://www.aerovisions.com/skyshark.html ,

 

then there was the aurora http://web.archive.org/web/20070108102534/http://members.aol.com/erospace/

 

and one more here http://www.etruria.com/index.html

[gontek]

I also found the Dreamwings Valkyrie and my former professor's company president told me about this:

 

http://www.avtechintl.com/

 

http://www.ultralightnews.com/airv98/airventure_valkyrie.htm

 

I've spent some time at the Library looking at Janes books lately, getting information on specs and performance. I think I am going to stick with the Cozy for the reputation of the plans and support network. Maybe after I get one homebuilt under my belt then I'll consider taking on a larger design mod project.

[emteeoh]

According to this, DreamWings went under in 2001.

[gontek]

Yes, John is still around and I hear considering bringing back the Valkyrie under LSA rule.

 

I looked up the Valkyrie performance specs in Jane's and from what I could quickly surmise it is not a high speed X/C crusing machine like I am looking for, nor would it be a plans build project. I ran out of change to make copies however so I need to go back to get the exact performance specs - I'll update those here at a later date.

[gontek]

So I pulled out my old computer with the Ashlar Cobalt and scaled a Piaggio down to size for a 2 seat tandem, and I have to say I think it's pretty sweet. I'm about ready to do a Class I design on this sucker.

 

I have seen a few aircraft lately using belt pulley reduction instead of reduction gear. That has given me an idea for integration of the engines but that's a topic for another forum thread.

 

I have been looking around in these threads a lot and noticed some previous talk about the piaggio 180 Avanti II. The great thing about the design of this airplane is the way it "synergises" design decisions that have benefits and drawbacks to take advantage. I donlt really want to change it at all, just scale it down to where I can take off and get great preformance with a piston engine or two for under a couple hundred horsepower. I like the look.

 

For the record, the design name I came up with is the "Piccolo"

[Lynn Erickson]

So I pulled out my old computer with the Ashlar Cobalt and scaled a Piaggio down to size for a 2 seat tandem, and I have to say I think it's pretty sweet. I'm about ready to do a Class I design on this sucker.

 

I have seen a few aircraft lately using belt pulley reduction instead of reduction gear. That has given me an idea for integration of the engines but that's a topic for another forum thread.

 

I have been looking around in these threads a lot and noticed some previous talk about the piaggio 180 Avanti II. The great thing about the design of this airplane is the way it "synergises" design decisions that have benefits and drawbacks to take advantage. I donlt really want to change it at all, just scale it down to where I can take off and get great preformance with a piston engine or two for under a couple hundred horsepower. I like the look.

 

For the record, the design name I came up with is the "Piccolo"

I hope you can make it work. this has been tried so many times you can't count them. not to burst your bubble but it does not work. it all looks good until you try to put people in the cockpit and behind the canopy. the size differences don't work scaled down unless you scale done the people too. you will be sitting under a canopy that you can't see out of. and a nose that is too small to sit in. but it is fun to think about. when you fly in one you realize that it is about as small as this design could be built and fit un-scaled down people.

[gontek]

Pilot visibility is definitely the biggest problem. Back seat forward visibility is also a biggie - there is none, unless you do like the Valkyrie and fly picthed forward, which adds lots of drag.

 

The Aeriks 200 was slightly pitched forward on the ground but still I don't think you could fly it form the back seat and see where you are going. I haven't drawn the canopy in yet but I an not that far into the design. I don't see how it would be that different than a long EZ. Actually there is more room than that at the current sizing. The goal is to (do what the piaggio does) cruise with the three surfaces trimmed for mimimum induced drag.

 

Thanks for the reply. I have no problem being told it can't be done, and you are probably right. However I have never let that stop me before.

[Lynn Erickson]

Pilot visibility is definitely the biggest problem. Back seat forward visibility is also a biggie - there is none, unless you do like the Valkyrie and fly picthed forward, which adds lots of drag.

 

The Aeriks 200 was slightly pitched forward on the ground but still I don't think you could fly it form the back seat and see where you are going. I haven't drawn the canopy in yet but I an not that far into the design. I don't see how it would be that different than a long EZ. Actually there is more room than that at the current sizing. The goal is to (do what the piaggio does) cruise with the three surfaces trimmed for mimimum induced drag.

 

Thanks for the reply. I have no problem being told it can't be done, and you are probably right. However I have never let that stop me before.

I am not saying to stop on the contrary it is a lot of fun to try and figure out these problems. but i have been there and have built full size mock ups to figure out this problem and and it is hard to make it all work unless the size of things is designed around a full size person. this makes the design about 1.5 times the size of a cozy. the long eze canopy is almost vertical where it contacts the top of the fuselage and curves back to the top of the canopy. if you project a line from the top of the canopy to the nose as in the Piaggio the canopy will be the length of the fuselage. if you don't go all the way to the nose with the canopy you will loose forward visibility. It will look like a sailplane canopy. and forward visibilty in sailplanes are not that good but they spend most of the time looking out the side in a bank anyway.

[gontek]

If you have any photos of the full size mock ups or anything I'd like to see that. I haven't got into the details of designing the canopy, I am still thinking about sizing, weight, and power considerations at this stage. However I have some papers from a source knowledgeable of the Piaggio, avtechintl RT-700, and Valkyrie so I am aware the visibility thing is an issue I'll have to deal with.

 

I'd shrug this off by stating that the mission intended here is to go far fast and cheap. Lets say in general I want missions of 1000 nm at 175kts on 60 gals of mogas, that seems reasonable offhand I think. Takeoff performance and landing performance of hopefully well under 2000'. The way I'd intend to use this plane is not for sightseeing. If I want to look out the window to see the trees and lakes I have a 172 that is great for that.

 

That said the Piaggio does have a rather unique fuselage shape. It has no cylindrical profile at any point which makes machining or construction a little more tricky and the Munk effect of the fuselage is -0.32 largest I know of. There is currently a lot of distance from the pilot's line of sight to the nose of the airplane in my CAD file, so that's about right.

 

I'll take suggestions on engines. There are so many to choose from which I like for so many different reasons. I was leaning toward twin rotax until I saw a used VW 1600 cc engine on ebay sell for $50 a couple days ago. (My wife wouldn't let me buy it still)

 

I have idea to get two small twins and locate them in the fuselage rear near the wingbox - landing gear intersection at the rear of the canopy. Belt drive twin props and run one engine out normally for economy cruise. It'd be like having a 8 cylinders and shutting down four cylinders like they do with indy cars nowadays. I can run redundant belts to props, and have added safety of two engines, and two engines for short takeoff or high performance cruise. Messes a lot up with my engine selection and installed weight though, and most of all has to fit there somehow. Haven't really seen it in action other than the Voyager either. Hey that's a Rutan canard!

 

Anyone have any experience with these props?

 

http://www.ivoprop.com/inflightmediummodel.htm

 

What I've read is pretty negative. Seems like a suspiciously cheap and mechanically frail way to incorporate variable pitch. How long have these things been around? Anyone able to share success stories?

 

ciao

[macleodm3]

Are you saying that you're going to run belts from your engines to your props? How far apart will the two pulleys be?

[gontek]

Span will have to be more than the prop radius, so 36" maybe?. I have seen lots of new ultralight gyrocopters running belts this far. I might need more than two.

 

I have found these:

http://www.bydanjohnson.com/articleart/145_1.jpg

 

http://www.geversaircraft.com/ac/propdrive.htm

 

The second has lots of variable geometry which I will be avioding. I would love to find out more about the first image though.

[Lynn Erickson]

 

I'd shrug this off by stating that the mission intended here is to go far fast and cheap. Lets say in general I want missions of 1000 nm at 175kts on 60 gals of mogas, that seems reasonable offhand I think. Takeoff performance and landing performance of hopefully well under 2000'. The way I'd intend to use this plane is not for sightseeing. If I want to look out the window to see the trees and lakes I have a 172 that is great for that.

 

I'll take suggestions on engines. There are so many to choose from which I like for so many different reasons. I was leaning toward twin rotax until I saw a used VW 1600 cc engine on ebay sell for $50 a couple days ago. (My wife wouldn't let me buy it still)

 

I have idea to get two small twins and locate them in the fuselage rear near the wingbox - landing gear intersection at the rear of the canopy. Belt drive twin props and run one engine out normally for economy cruise. It'd be like having a 8 cylinders and shutting down four cylinders like they do with indy cars nowadays. I can run redundant belts to props, and have added safety of two engines, and two engines for short takeoff or high performance cruise. Messes a lot up with my engine selection and installed weight though, and most of all has to fit there somehow. Haven't really seen it in action other than the Voyager either. Hey that's a Rutan canard!

 

Anyone have any experience with these props?

 

http://www.ivoprop.com/inflightmediummodel.htm

 

What I've read is pretty negative. Seems like a suspiciously cheap and mechanically frail way to incorporate variable pitch. How long have these things been around? Anyone able to share success stories?

 

ciao

if your mission is far fast and cheep I would say take a commercial airline. if on a 1000 mile mission your design turns out to be more efficient then the airlines it would be a first. far and cheep can be done with many designs but it is the fast part that will cost you dollars in fuel and HP. then add the twin engine to the mix and the efficiency goes down even more. a twin with engines to small to keep the aircraft in the air on only one engine is not really a true twin and not any safer then a single.

As for the VW well they were good to get people to the market or a Stones concert.

the Ivo prop has been a good prop on many aircraft. they are not recommended for 4 cylinder engines. they have a limited amount of pitch change. In My opinion not worth the small performance gain. I have not flown behind one but have flown along side one. and did not see the gain both aircraft got off in less the 2000 ft. top end is good but not as good as a fixed pitch

[gontek]

if your mission is far fast and cheep I would say take a commercial airline.

Waited in line for security lately? I can fly at 152 speeds and beat the airlines to some places, like Wichita, Naperville or Omaha.

 

if on a 1000 mile mission your design turns out to be more efficient then the airlines it would be a first. far and cheep can be done with many designs but it is the fast part that will cost you dollars in fuel and HP.

I neglected to mention than fun and experience are also on the mission criteria list.

 

then add the twin engine to the mix and the efficiency goes down even more. a twin with engines to small to keep the aircraft in the air on only one engine is not really a true twin and not any safer then a single.

 

I think OEI climb is a requirement for FAR 23, if it's not I'd definitely like to know that before I jump in and go for a ride. OEI Performance is obviously degraded. I suppose homebuilts don't have to meet FAR 23 but I am not a total idiot, and I would design to meet FAR 23 or MIL specs where FAR23 is too vague. Maybe it won't work. I'd like to see your OEI calculations and engine assumptions for this statement. Otherwise you are stating the obvious and wasting my time.

 

the Ivo prop has been a good prop on many aircraft. they are not recommended for 4 cylinder engines. they have a limited amount of pitch change. In My opinion not worth the small performance gain. I have not flown behind one but have flown along side one. and did not see the gain both aircraft got off in less the 2000 ft. top end is good but not as good as a fixed pitch

Thanks for this information and your opinion on this. Where do you find information about these not being for 4 cylinder engines?

[Lynn Erickson]

Waited in line for security lately? I can fly at 152 speeds and beat the airlines to some places, like Wichita, Naperville or Omaha.

 

 

 

I neglected to mention than fun and experience are also on the mission criteria list.

 

 

 

I think OEI climb is a requirement for FAR 23, if it's not I'd definitely like to know that before I jump in and go for a ride. OEI Performance is obviously degraded. I suppose homebuilts don't have to meet FAR 23 but I am not a total idiot, and I would design to meet FAR 23 or MIL specs where FAR23 is too vague. Maybe it won't work. I'd like to see your OEI calculations and engine assumptions for this statement. Otherwise you are stating the obvious and wasting my time.

 

 

 

Thanks for this information and your opinion on this. Where do you find information about these not being for 4 cylinder engines?

Now thats different. if you say you want to have fun while flying thats really going to cost you a lot more. just kidding. if you are to use lets say two - 100 HP engines on a for place twin aircraft and one goes out the 100 HP engine is not going to be enough to maintain safe flight. if you use 2- 150 HP engines you may have a safe plane on one engine but now you are fly a 300HP machine and you are not going to go 1000 nm on 60 gallons of av gas.

Ivo will not sell you a prop if they know it is going on a 4 cyl. engine. they have had hub and blade failures do to the high power pulses and vibration of 4 cyl. engines

[Marc Zeitlin]

I think OEI climb is a requirement for FAR 23, if it's not I'd definitely like to know that before I jump in and go for a ride.

FAR 23.67 defines the requirements for OEI climb gradient. Generally, it's 1.5% at 5K ft. pressure altitude, although there are many other conditions as well.

I suppose homebuilts don't have to meet FAR 23...

That is correct.

but I am not a total idiot, and I would design to meet FAR 23 or MIL specs where FAR23 is too vague.

Good luck with that. Very few homebuilts would come close to meeting the part 23 requirements - that's why there's a lot of redesign required when folks like Lancair decide to certificate their aircraft.

 

Mil Spec, huh? Yeah...

 

Certainly NONE of the canard composite aircraft are anywhere near all of the part 23 reqs.

Thanks for this information and your opinion on this. Where do you find information about these not being for 4 cylinder engines?

IVO has long since refused to sell props to folks that intend to put them on Lycoming 4-cylinder aircraft engines. Can't take the torque pulses.

[gontek]

 

Good luck with that. Very few homebuilts would come close to meeting the part 23 requirements - that's why there's a lot of redesign required when folks like Lancair decide to certificate their aircraft.

 

Mil Spec, huh? Yeah...

 

Well I have to use some soft of criteria so I don't kill anyone. I find Mil is useful for guidance too because a lot of the FAR23 statements are akin to "motherhood is good." As far as redesigning for certification - why not do it right the first time?

 

Certainly NONE of the canard composite aircraft are anywhere near all of the part 23 reqs.

 

None you say? I beg to differ - Piaggio 180 is FAR 23 certified. That's what we are discussing here, right- Copying the P-180? I suppose we could argue about that being a true canard though. I won't bring up the Starship.

[Marc Zeitlin]

As far as redesigning for certification - why not do it right the first time?

Because it's expensive and time consuming? Ask Dick VanGrunsven and Burt Rutan why they don't design to Part 23 (unless they want to, in some areas).

 

None you say?

None of the experimentals - that was the point.

 

I beg to differ - Piaggio 180 is FAR 23 certified. That's what we are discussing here, right- Copying the P-180?

Hey - you want to copy a certificated aircraft, shrink it, and make the shrunken version part 23 compliant - have at it. It's your time and $$$. All I was pointing out was that if there are any experimental amateur built aircraft that are part 23 compliant, they're extremely few and far between, and none of the Rutan derivative canard composite experimental amateur built aircraft fit into that exclusive category.

 

I won't bring up the Starship.

Also certificated - not experimental. I guarantee you that the first Starship experimental prototype, built by Scaled, was not part 23 compliant.

[gontek]

This is an interesting group of people here. I have noticed this kind of trend on lots of the forum posts I have looked at here. I think it probably has something to do with everyone being a perfectionist.

 

I should make clear that I don't intend to certify anything here, rather use the certification standards as guidelines for something very experimental. I'll do a design, document it, and chances are, it will be a dog for some reason.

 

I would start building a Cozy but my wife is against it. I'll fly my Cessna when the weather is good and I am not in a hurry to get somewhere. I was once trained in the art and science of aircraft design, so I am having fun doing it again (or at least going through the motions) and learning more.

[Richard Schubert]

Originally Posted by Marc Zeitlin

Certainly NONE of the canard composite aircraft are anywhere near all of the part 23 reqs

Originally Posted by Gontek

None you say? I beg to differ - Piaggio 180 is FAR 23 certified.

The Piaggio 180 is all metal structure

 

Stopping when ahead

[gontek]

 

 

The Piaggio 180 is all metal structure

 

Stopping when ahead

 

Well yeah, if by all you mean 95%.

[macleodm3]

I can't tell if you are pulling legs here with this belt driven prop idea. The Wright brothers had some kind of belt or chain drive to their props, but you say that Rutan used this too?

 

I think it sounds crazy. I've worked around some high horsepower belt driven stuff. We have 100hp to 200hp belt driven fans (when it is a temporary fan). The belts a very heavy, and they must be stretched tight in order to not slip. Plus, even when tight, they flop and bang around alot at our fan rpms (1200 to 1800 rpm). They slip and squeal. It takes a STRONG frame to get the belts tight and prevent the pulleys from being pulled together.

 

The cog belts are just as bad, as its very easy to get slightly our of "perfect" and the belts start loosing teeth.

 

Belts seem to work for a short span, like psru type application, but not for remote props on a lightweight, fast, composite aircraft.

 

Maybe you could go with hydraulics, or elecric instead.

[Edge 513]

I think I am going to stick with the Cozy for the reputation of the plans and support network. Maybe after I get one homebuilt under my belt then I'll consider taking on a larger design mod project.

I think back here on post 3 or whatever this quote from you above, was is where you is threwin' us regarding now stating you wife not allowing you to build a Cozy....but will let you build a little Piaggio wannabe...with no money...but a lot of time...**

 

I think I am missing the punchline. Are you sure you're not Richard Pryor reincarnate?

 

**I almost added...with a rubber band belt-drive....but I didn't, just between you-n-me.=/

 

I can never quite no say things right sometimes.[cue the duelin banjo musick]

[gontek]

Oh man, this forum thread is getting out of hand.

 

I am not building anything for a while. I doesn't take any money for me to crunch numbers and use software leftover from college. And to date, I have about 2 hours invested in actual design time, other than reading my Jane's AWA and old engineering books. Some of you have been building or built for 10 years. Give me a break. RV's are starting to look more appealing - no I won't go that far, I take it back. I love airplanes and I wanna be a cozy guy. My supreme dictator says no - with this face:

 

Part of the process as I know it is investigating the state of the art and available technology. That's all I am doing here, is having a discussion. I have crazy ideas. You have actual building experience. The meeting of these things does have me feeling like I am standing on a stage with a broken banjo and no pants. But I am learning. And if I didn't have a sense of humor I wouldn't keep coming back to this thread.

 

So now I'll just slowly back away. you are all right. I was joking the whole time, yeah, that's the ticket. yanking your chain. Trolling. Just go on about your business. Nothing to see here.