Is the RV-10 better than the Cozy?

[Marc Zeitlin]

.. dropping off a passenger and needing to move ballast to the front seat. Is it really that sensitive? I am suprised.

It will depend upon how much you weigh, how much your passenger weighs, and where you determine to place your empty CG. I weigh 150 dripping wet, and if I want to fly solo, I need 55 lb. of lead in the nose. This allows me the flexibility to take front seat passengers up to 300 lb. If I set my plane up so that I didn't need any front seat ballast, I would only be able to take passengers that weighed up to 200 lb. or so. When I fly with anyone that weighs more than ~100 lb. in the front seat, I remove the ballast and store it in the back. You can load the rear seats with any amount of weight you want (without overloading the aircraft) without having to move any ballast - the rear seats are just about on the CG.

 

** I am also interested in the Cozy, but I hear that factory support is a bit less than friendly for some people.

There's no such thing as a factory. Support comes from a few sources - first, Nat Puffer (although the company has been sold to Aircraft Spruce). Secondly, the COZY newsletter. Thirdly, and most actively, the COZY email mailing list (see my signature below for URL). Fourth, the canard-aviators mailing list and the CSA newsletter. Nat can be, how to say, curmudgeonly at times, but between all the info sources, you will be buried in answers before you can shake a stick.

 

- Minimize cost as much as possible, so that I can maximize on-board equipment. (I want the works in the panel.)

- I want it reasonably comfortable for long flights.

- I want fast... as fast as possible. (200Kt +?)

- I want long range... as long as possible. (1,000 NM+?)

- I want easy and fun to fly

- I want a SAFE, proven design or variant thereof

- I want an engine and airframe that I can work on, maintain, etc... avoiding paying people. (I am not wealthy.)

All these things are available from both the RV-10 and the COZY. Both will be comfortable and fast (the RV a bit more roomy, and the COZY a bit faster). Both will have good range, with the COZY getting the nod here, too. Easy and fun is a wash, depending upon your definitions of easy and fun. Safe, the same - both are great planes. You can work on any homebuilt - hell, you built it, you can work on it.

 

All the rest of your desires are pretty generic, and can be obtained from many different designs. The COZY will cost a bit less both to build and to operate than other 4-seaters, due to it being plans built rather than kit built, and due to it having a smaller engine than the RV-10 and some other 4-seaters. The COZY plans are very good, and with the support network that's available, even your monkey could build the plane :-).

 

I need to build it in a small 2-car garage in Orange County, CA.

Eminently doable - been done by many (including me) before.

[interestedbutconfuse]

These two were also my 'final contenders'.

I chose the Cozy for the following reasons:

 

1. Same speed with less HP - RV-10 needs 260 hp, Cozy 180hp

2. Better fuel economy because of above.

3. Engine costs less, and maintenance of that Engine costs less (smaller HP = cheaper usually)

4. I liked the looks of the Cozy better (vain I know)

5. I preferred the 'pay as you build' mode to the kit mode. This wasn't as bad with the RV since you could get the kit in 'chunks', but then you paid more freight. The freight was a deal for me since I am within easy driving distance of Wick's

6. Less money spent on tools.

 

All that, it was a very close race, and I don't think you'll regret either one.

Mark

[Daniel Dillon]

I am also considering a Cozy... but my decision is between the Cozy MK IV and a Long EZ.

 

I am strongly leaning toward the Cozy at this point, but I have a million questions about homebuilding and other things at this point. After years of looking into it, talking to people, and reading... I wil be starting something (likely a Long EZ) by mid-2005.

 

Happy New Year,

 

Dan

 

 

 

I am considering building a plane and my top contenders are the Cozy and RV-10. The advantages I see of the RV-10 over the Cozy are the ability to operate from grass strips, short takeoff/landing distance, and more useful load. Disadvantages of RV-10 are initial cost and fuel economy.

 

I would like to hear from Cozy builders/flyers your opinions of these airplanes and the advantages/disadvantages of each.

[Jon Matcho]

Support comes from a few sources - first, Nat Puffer (although the company has been sold to Aircraft Spruce). Secondly, the COZY newsletter. Thirdly, and most actively, the COZY email mailing list (see my signature below for URL). Fourth, the canard-aviators mailing list and the CSA newsletter. Nat can be, how to say, curmudgeonly at times, but between all the info sources, you will be buried in answers before you can shake a stick.

Marc, on the topic of support, let's not forget this particular forum which some prefer over (or in addition to) other sources of support.

 

...my decision is between the Cozy MK IV and a Long EZ. I am strongly leaning toward the Cozy at this point...

Here's an analogy that may help you decide: A Long EZ is to a motorcycle as a Cozy Mark IV is to a sports car.

 

Any canard brand vehicle is welcome here!

[Daniel Dillon]

I like that.... and maybe I should build one of each because I love motorcycles and sports cars.

 

Currently I ride a Honda Interceptor (VFR800) with the Honda Vtec Fuel Injected 4-cyl.

 

I am a former owner of an RX-7 with the famous 13B engine. I swear by those engines, I loved that car. It was my pride an joy until I got stolen. (Always a silver lining... the insurance was very good to me, I paid off my bills, could re-focus on my education, and now I can build an airplane albiet with substantial financial struggle.)

 

The Cozy MK IV is my target, although I have the plans for the Long EZ.

 

Marc, on the topic of support, let's not forget this particular forum which some prefer over (or in addition to) other sources of support.

 

Here's an analogy that may help you decide: A Long EZ is to a motorcycle as a Cozy Mark IV is to a sports car.

 

Any canard brand vehicle is welcome here!

[Daniel Dillon]

I don't quite trust kits. They can go out of business and leave you hanging too easily.

 

I'm going to have to be a plans-built kind of guy with the hope to buy as much prefab as possible in the interest in reducting the time-to-fly.

 

Dan

 

 

These two were also my 'final contenders'.

I chose the Cozy for the following reasons:

 

1. Same speed with less HP - RV-10 needs 260 hp, Cozy 180hp

2. Better fuel economy because of above.

3. Engine costs less, and maintenance of that Engine costs less (smaller HP = cheaper usually)

4. I liked the looks of the Cozy better (vain I know)

5. I preferred the 'pay as you build' mode to the kit mode. This wasn't as bad with the RV since you could get the kit in 'chunks', but then you paid more freight. The freight was a deal for me since I am within easy driving distance of Wick's

6. Less money spent on tools.

 

All that, it was a very close race, and I don't think you'll regret either one.

Mark

[KeithO]

Something I have not yet seen mentioned is surviveability of an off field landing. I think the RV10 will win that one hands down. The high landing speed and the small wheels with high center of gravity (due to pusher prop clearance) tends to mean that you would be very lucky indeed to have an damage free landing on anything other than a long stretch of asphalt. I know that a lot of people have walked away from off field landings but in virtually every case the airplane was destroyed.

 

It is the primary reason I have hesitated to start building. A 3 wing design with front mounted engine would most likely be the most forgiving configuration, but aerodynamically the most complicated to execute. It does away with the pusher prop issues, alows flaps for better approach speeds, shorter landing gear. Of course the view is spoiled somewhat and the cabin is in the prop wash so it will be noisier. 3 flying surfaces means a tail, so the wing can be straight (improves some of the stall characteristics).

 

Composite construction damps vibration better without the drumming and "oil canning" of sheet metal, so the "quality" of the sound inside will be superior. And properly executed, composite can be very strong and does not have to shatter on impact.

I'm still sitting on the fence as you can see....

[emteeoh]

KiethO:

 

I'm not sure you're right about a variety of things here.

 

Survivability: My general impression is that composites tend to do better. They might appear to take more damage, but they are also much easier to repair.

That they take more damage is debateable too. They're lighter planes, no? That would suggest less kinetic energy in any accident. pound-for-pound, composites are stronger which means that in comparable accidents, the composite plane should have to dissipate less energy and have more strength to do it in.

 

3 flying surfaces: maybe it sounds better, but what about drag? More wings could mean more drag which probably means a less efficient plane. I've read a claim by an aerodynamics expert (he was a prof somewhere...) that the conventional airplane design is in fact the most efficient design. He claimed that mostly on the basis of drag: in straight and level cruise, the tail should be in a mostly neutral lift config, which means little drag, which should mean that all your drag is directly caused by the main wing. A canard, he claimed, would have more drag since you have 2 lifting surfaces, both loaded, and the smaller airfoil is likely, he argued, a less efficient airfoil.

So he's made a myriad assumptions, but you at least have to admit that its not a simple design issue. If it was, every plane would look like the piaggio.

 

 

Having said all that, don't trust me: I'm not a builder, nor a materials expert, nor a plane designer. I'm not even a solo-ing student pilot yet. I would wait until Marc Z. shreds my comments before taking them as anything resembling fact. I look forward to it, personally.

[Tyson]

KiethO:

 

I'm not sure you're right about a variety of things here.

 

Survivability: My general impression is that composites tend to do better. They might appear to take more damage, but they are also much easier to repair.

That they take more damage is debateable too. They're lighter planes, no? That would suggest less kinetic energy in any accident. pound-for-pound, composites are stronger which means that in comparable accidents, the composite plane should have to dissipate less energy and have more strength to do it in....

 

Theory vs reality. While composite materials might be stronger ounce per ounce, composite planes generally weigh as much as planes made from other materials. A LongEz at 1400 pounds carries as much energy into a crash as a RV-4 at the same landing speed. But of course the RV-4 lands slower.

 

On kinetic energy, recall that it equals 1/2 * m * v^2. So some simple calcs finds that the KE (in relative units) = :

LongEz 1400 pounds 65 knots: 2,520,500

RV-4 1400 pounds 50 knots: 1,750,000

Cozy IV 2050 pounds 70 knots: 5,022,500

RV-10 2700 pounds 58 knots: 4,541,400

 

Recall that speed doesn't kill, it's the sudden stop. So you want the airframe to be able to dissipate energy. Maybe the designer has helped you out here. Maybe you need to dig a wingtip on touchdown. At any rate, speed is squared in the above equation and as such marginal changes in mass (structural weight) are much less important from a KE standpoint. And any talk about which experimental airframe tears apart more favorably is entirely nebulous.

[TMann]

The RV does look pretty cool. A guy in our EAA chapter presented his at our October meeting. Very nice.

 

I was amazed as to how much of the plane was pre-built. It's more like assembling some parts vs. the plans built solutions.

 

Bottom line, If you want a plane fast and you find the design acceptable then by all means get an RV.

 

Myself, I'll stick with my plans built Long-EZ. (It's gonna be a dragstah!)

[argoldman]

Theory vs reality.

 

Recall that speed doesn't kill, it's the sudden stop. So you want the airframe to be able to dissipate energy. Maybe the designer has helped you out here. Maybe you need to dig a wingtip on touchdown. At any rate, speed is squared in the above equation and as such marginal changes in mass (structural weight) are much less important from a KE standpoint. And any talk about which experimental airframe tears apart more favorably is entirely nebulous.

IDONNKNOW.....

 

True it is the sudden stop that kills, but there is no such thing as a sudden stop. All stops happen over a time period, although seemingly short (much shorter, if you auger in), however in a "normal" accident. The deceleration happens more slowly. The auto industry has addressed this problem by adding crumple zones to their cars, which, I believe, has increased the survivability of MVCs dramatically. The material and structure of glass aircraft seem to have this capability built into the material and structure, not so Spam containers.

 

Glass is a wonderful material. Having been in front end collisions in corvettes and metal cars, and one glass aircraft "arrival," I would much prefer the glass. The sudden stop is much less sudden.

 

"Some think that the world will end in fire, some think in ice. From what I've tasted of desire, I hold with those who favor fire. But if I had to perish twice, I also think that ice is nice and would suffice!":p

[Tyson]

Glass is a wonderful material. Having been in front end collisions in corvettes and metal cars, and one glass aircraft "arrival," I would much prefer the glass. The sudden stop is much less sudden.

 

The fiberglass in a Corvette is a crumple zone as compared to a Buick with steel running all the way up front.

 

Recall that in RAF's early building videotape Burt demonstrates the strength of the composite structure vs an aluminum structure. Essentially what could be described as a tail structure was built where one half was epoxy/glass, the other was standard aluminum/rivets. Burt and Mike simultaneously jump on each side of the structure that is supported at the tips.

 

Mike, who weighs less, crumples and fails his aluminum side whereas the heavier Burt doesn't seem to cause any damage to the fiberglass composite side. Whereas the aluminum crumples/fails, the composite leaves Burt's bones/joints/disks to accept the majority of the deceleration. I believe both Burt and Mike proceed to both jump on the composite side without failing it.

 

What this means in the real world is again nebulous. Different crash scenarios might favor either composite or aluminum or even wood. In the real world I doubt there are instances where one looks at a crashed plane with fatalities saying "they would have made it if this thing was built from composites" (but probably lots of instances where they would have made it if they didn't hit so damned fast). Generally speaking, composite airframes seem more rebuildable after crashes whereas aluminum structures are a write-off (too many creases/bends here and there). It takes energy to deform the structure...energy I'd rather have the structure soaking up instead of my innards. YMMV

 

At the end of the day it's energy that kills. Your brain sloshes around inside your skull. Your organs slosh around getting bruised and tug on arteries not up to the task. You want to do anything you can do to minimize these forces. Having a superlatively strong airframe does not help you here.

[Ron Springer]

Generally speaking, composite airframes seem more rebuildable after crashes whereas aluminum structures are a write-off (too many creases/bends here and there).

Rather than indicating the degree of damage, it could be that composite airframes are just much easier to build from scratch and to repair after an accident. After crashing an aluminum airframe, you are typically better off starting over and buying another mass produced kit.

[DemonFrog]

If it comes to landing in an unimproved field i think that unless you have alaskan tires on the rv i would much rather belly land something like an ez with retracts. also, the cool factor of retracts is something the rv aircraft are missing IMHO. as far as forced approaches, what about glide ratios? an rv that is used to the propwash increasing lift would have a lower glide ratio would it not? i would much rather glide to an improved field than land in a farmers anyday.

[bferrell]

Something I have not yet seen mentioned is surviveability of an off field landing. I think the RV10 will win that one hands down. The high landing speed and the small wheels with high center of gravity (due to pusher prop clearance) tends to mean that you would be very lucky indeed to have an damage free landing on anything other than a long stretch of asphalt. I know that a lot of people have walked away from off field landings but in virtually every case the airplane was destroyed.

 

I'm still sitting on the fence as you can see....

I'm not sure this is supportable, though I can see why it may seem this way.

 

I know several folks who've landed Velocity XL airplanes off-field with no damage at all, and some with very minimal damage, and they are typically much heavier than Cozys. Now, our wheels are bigger, but we're heavier, taller, and fast. I've collected as many pictures as I could to show how survivable they are on my website http://n44vf.velocityxl.com/building/Accidents.php

 

Brett

[Wayne Hicks]

<was said:> "Mike, who weighs less, crumples and fails his aluminum side whereas the heavier Burt doesn't seem to cause any damage to the fiberglass composite side."

 

----> I don't have a dog in this RV10 versus Cozy fight, but a close look at the video shows Mike jumping much higher than Burt and landing on the sections of skin not supported by the spar or the ribs. On the composite section, both Mike and Burt are jumping from and landing on the spar. I guarantee that if you jump on a composite canard or wing section on the foam/skin combination, you'll put a big dent into it with delamination to follow. True, you might not fail the composite structure, but, short of skydivers colliding onto planes, when was the last time anyone heard of something falling onto the top of, and damaging an aluminum a wing in flight?