Max width of the Fuselage.

[deronjthomas]

With in the next years or two my brother and I are going to start building a aircraft. I’m 5’10”, and he is 6’1”. The only other problem is that we both have very large shoulders. Dose any know how wide a custom Cozy Mark IV has been made? The other option is to make it a Cozy Mark IV 2+Place, or put in a bench seat. I’m open for suggestions.

[Jon Matcho]

I know widened Cozys are being built, and maybe some are even flying, but first understand that there's no sort of "official" design for widening a Cozy beyond the plans dimensions.

 

There are a couple things you could do to get more shoulder room without widening the design:

• Put the longerons flush with the outside of the fuselage skin (as opposed to the behind the foam on the inside)
• Use thinner foam for the armrests as well as contour more closely to the control rod
• Do the "Cozy Girrrl Strakes" modification

All of these options need to be researched. Again, there are no formal plans for these modifications.

 

Making a Cozy Mark IV into a 2-place is an interesting thought for large people. The only issue I see is that the width would then be too wide for even a large person. The control stick would be too far to the left/right to sit in the middle, so you'd be sitting on the left anyway.

 

Finally, you need to find yourself a 100% per-plans Cozy Mark IV and ask the owner to let you sit in it. You might find that you really don't need to do that much in this area.

[Steve Innova]

I built a 3" wider fuselage that I am selling for unrelated reasons-- see my "for sale" posting.

[argoldman]

With in the next years or two my brother and I are going to start building a aircraft. I’m 5’10”, and he is 6’1”. The only other problem is that we both have very large shoulders. Dose any know how wide a custom Cozy Mark IV has been made? The other option is to make it a Cozy Mark IV 2+Place, or put in a bench seat. I’m open for suggestions.

Greetings Der,

 

Another approach would be make a stagger cozy MK IV converted to a 3 1/2 place with the front seats staggered to give shoulder room. We used to do that in my Mooney. You would then have 1 full size back seat, and 1 for a shortie. W&B should be no problem with that change.

 

Additionally you will have the preception of a regular length nose from one seat and an extended nose from the other seat.

 

your problem with two side by siders is not the seat width, although somewhat small. Removal of the center console will give some but room but will do nothing to increase the shoulder room that two brutes need.

 

If you do take out the center console, make sure that you think of how you will get heat to the back seat and engine controls back to the engine.

[Remi Khu]

I might be wrong but aren't the Cozy seatback and the heat duct structural components? Do they (seatback and heat duct) provide some measure of horizontal and longitudinal strengthening?

 

What would happen if those structures are eliminated or weakened??

[Nathan Gifford]

I might be wrong but aren't the Cozy seatback and the heat duct structural components? Do they (seatback and heat duct) provide some measure of horizontal and longitudinal strengthening?

 

What would happen if those structures are eliminated or weakened??

Yep Remi, that's what I was told too.

[Jon Matcho]

What would happen if those structures are eliminated or weakened??

This is a question for Steve Wright... and dang, I meant to ask this exact question just this past weekend!

[Remi Khu]

Pure conjecture of course, but it appears that Wright made his fuselage from molded composite, perhaps there are some additional buildup elsewhere that allow for the elimination of the seat back and heat duct.

 

You're right, you should've asked him that question!

[deronjthomas]

The width of the Cozy is 42". If we where to add 18" to make it 60"; dose any one know how that would effect the aircraft? I know it would add weight, but I don't know how much. Alternatively, I could just forget about expanding the width of the Cozy, and just make my brother sit in back.

[Jon Matcho]

The width of the Cozy is 42". If we where to add 18" to make it 60"...

This would be the largest Cozy widening ever. Most have talked about widening between 1" and 6", so 18" (9" on each side) is rather over the top. Measure a Cessna and you'll find that the per-plans Cozy is WIDER. Even a brand new Cessna 182 is 42". Sure, there are some things that can be done to make it feel wider, but for the most part it's not so bad as-is.

 

...[does] any one know how that would effect the aircraft? I know it would add weight, but I don't know how much.

I wouldn't want to be a test pilot of anything widened over 2". That's not to say that a wider canard aircraft won't fly -- they do -- but I'm not going to be the first to find out.

 

I've also been told, and have swallowed this bit of bitter advice as well as I could: "Build a Cozy completely to plans and fly it. If you still feel you need any major changes, build a second."

 

Finally, check www.velocityaircraft.com. Their 'eXtra Large' model is 47.5" wide. You could either build that kit, or consider some widening and other non-structural adjustments for additional elbow room.

[Nathan Gifford]

The width of the Cozy is 42". If we where to add 18" to make it 60"; dose any one know how that would effect the aircraft? I know it would add weight, but I don't know how much. Alternatively, I could just forget about expanding the width of the Cozy, and just make my brother sit in back.

The widest Cozy derivative (or should it be LongEZ derivative??) I heard of was 12" and that was a major undertaking (and it ain't flyin yet!!) Its a lot more than just widening the structure.

 

You might do much better building the Cozy as two-seater. Least ways, I think it would be a safer ship to build and fly.

[rnbraud]

John Matcho said:

 

# Put the longerons flush with the outside of the fuselage skin (as opposed to the behind the foam on the inside)

 

 

John, I would like to hear more about this mod. It seems like an easy change, however, I haven't found much discussion on it.

 

Later.

[Steve Innova]

Best advice I could give you:

 

Make a wooden mockup of the fuselage, using plywood or cardboard. Something real simple. Install a seatback at 45 degrees, use cushions to simulate the seat. Separate the sides until you have something that works for you and your brother. That way you can narrow down the design.

 

For reference, the sides are about 22" high. The instrument panel is 37" wide or so, the seatback is 42" wide.

 

By the way, 60" is bigger than a honda Civic, I think. That's too big for a single engine plane.

[CFernandez]

If we where to add 18" to make it 60"; dose any one know how that would effect the aircraft? I know it would add weight, but I don't know how much. Alternatively, I could just forget about expanding the width of the Cozy, and just make my brother sit in back.

If you want to design, build and test a 60" wide Cozy-like aircraft I would love to see you do it...why...because there is absolutely nothing to stop you... except...you.

 

My 2 cents.

 

The Cozy takes 160-200hp at 42" wide, the Velocity XL takes 260-300hp at 48" wide, the deronjthomas-canard at 60" wide takes how many ponies?

 

It seems to me that by the time you designed, built and tested this new canard you could have built a Velocity XL and been well ahead.

 

Try on the Velocity XL, check the specs, call Velocity and ask about front seat weight. I think you will like it.

 

The tandem seat Cozy idea sounds really good though (and easy to do) Again, there is absolutely nothing to stop you...

[Steve Innova]

The tandem seat Cozy idea sounds really good though (and easy to do) Again, there is absolutely nothing to stop you...

I disagree. The rear passenger would not greatly enjoy the ride in a tandem seat cozy. There is little visibility, and the [plans] Cozy has less headroom in the rear seat than in the front seat.

 

I hate to say it, but for really large people who want to sit side-by-side, you'd do better with a conventional aircraft. In most conventional 2 seat aircraft, the seats are positioned directly above the aircraft wing and center of gravity (usually). This makes them less sensitive to having heavy(er) weights (passengers) in the seats. As long as they can fit, large people can usually fly with a reduced fuel load without compromising the delicate wieght and balance of the aircraft.

 

On the other hand, the front seats in the Cozy are ahead of the center of gravity, making the Cozy MUCH MORE sensitive to overloading in the front seat. The max front seat weight in the Cozy is between 400 and 450 lbs. Widening the fuselage isn't going to change that, and flying out of CG could be lethal.

 

Build a plane that meets your mission requirements. If your mission requirements include 2 large people, side by side, with a combined weight of more than 400 lbs, you should consider a conventional 2 seater.

[Jon Matcho]

I disagree. The rear passenger would not greatly enjoy the ride in a tandem seat cozy. There is little visibility, and the [plans] Cozy has less headroom in the rear seat than in the front seat.

I'll disagree with you Steve. The Long-EZ works just fine for two people as a tandem, and they get out with big smiles on their faces just like people do out of Cozys.

 

You can improve visibility with larger windows, and even lower strake windows. Many builders have increased rear headroom by raising the turtledeck an inch or two. Also, there is no headroom issue if you sit in the middle of the back seat -- ever do that -- it's plenty big!

 

Finally, measure the width of the vertical leg hole separator in a Long-EZ and compare with a Cozy -- they're exactly the same. To fit 2 passengers, Nat widened each leg hole to fit two legs each (or one big leg each).

 

I don't see anything wrong with building a Cozy Mark IV or III as a tandem and calling it a Wide-EZ.

[Nathan Gifford]

...If you want to design, build and test a 60" wide Cozy-like aircraft I would love to see you do it...why...because there is absolutely nothing to stop you... except...you...

...AND THE GROUND...

[Steve Innova]

I'll disagree with you Steve. The Long-EZ works just fine for two people as a tandem, and they get out with big smiles on their faces just like people do out of Cozys.

1. The Long EZ has an all glass canopy. There's no comparison between a bubble canopy and the Cozy's turtleback for the rear seats. To get the same effect in a Cozy, you'd need a new canopy. (Doable)

 

2. The Long EZ also has slightly smaller strakes, which makes it [marginally] easier to see the ground ahead of you.

 

You could modify the cozy to be a tandem aircraft, but if you do that you're really giving up the big advantage of a cozy, that it's a 2+2. I stand by what I said, blasphemous as it may be.

[CFernandez]

I disagree. The rear passenger would not greatly enjoy the ride in a tandem seat cozy. There is little visibility, and the [plans] Cozy has less headroom in the rear seat than in the front seat.

Steve, I agree with you, the visibility may not be as good as a front seat, but if building a tandem Cozy or side-by-side "whatever" conventional airplane were the two options, I would build the tandem Cozy in a heart beat.

 

For what deronjthomas wants to do, a tandem Cozy would be within limits of the current Cozy compared to "something else", 60" wide. Even if he were to change the turtleback, get some engineering help and do it.

 

...AND THE GROUND...

That would not stop him from designing, building and testing (the first time). If that were the case we would all be sitting in the grass wondering what it would be like to fly...instead we get to watch people like Mike Melville corkscrew into outer space. I'll say it again design, build, test whatever it is.

 

I guess what I'm saying is don't let anything stop you. If you want to do something, educate yourself and do it. It is that easy. (Easier said than done, I know.)

[Jon Matcho]

To get the same effect in a Cozy, you'd need a new canopy. (Doable)

Good point -- the per-plans back-seat view is not so great. However, there are ways to maximize the viewable area:

• Increase window sizes
• Add strake windows
• Redesign entire turtleback
• Add in-flight LCD "ground/scenery cam" (for my kids)

You could modify the cozy to be a tandem aircraft, but if you do that you're really giving up the big advantage of a cozy, that it's a 2+2.

Let's be honest... it's really 2 FAA standard-sized adults in the front, PLUS 2 kids OR 1.5 FAA standard-sized adults OR baggage in the rear.

 

A better way to look at the notion of a tandem Cozy is to KEEP it a 2+2 place, but just add a little more luxury to the back seat. There's nothing wrong with someone flying in the front, even widening the left leg hole more than the right, and having a passenger in the right. Heck, make it a StaggerCozy while you're at it. Bench seats are not a bad idea -- the AeroCanard kit has them!

 

I stand by what I said, blasphemous as it may be.

Your argument was about weight and balance; that you could be less careful/accurate in a 'conventional' aircraft than in a canard and still fly. This is a different topic -- pilots need to follow the POH and do W&B calcs on ALL aircraft before flying. Assuming you do not dismiss that responsibility, two big boys CAN fly in many airplanes, but many of those airplanes will not have performance comparable to a Cozy.

 

While on the topic of convential vs. canard aircraft, be sure to check out Nat Puffer's EAA AirVenture 2005 presentation titled 'Cozy Aerodynamics 101' http://www.cozybuilders.org/Oshkosh_Presentations/index.htm That might confirm your decision to pursue a canard aircraft -- it did for me.

[Steve Innova]

Your argument was about weight and balance; that you could be less careful/accurate in a 'conventional' aircraft than in a canard and still fly.

I didn't say you could be "less careful/accurate" in a conventional aircraft -- What I said was most conventional planes give you more flexibility to trade fuel capacity for front seat weight, since both are usually carried directly above the aircraft CG. The Cozy on the other hand carries its fuel over the CG, but its passengers ahead of the CG.

 

Build whatever the hell you want, just don't make your decision based on an emotional attatchment to a particular airframe -- consider your absolute mission requirements / cost / ease of construction, and chose accordingly.

[Jon Matcho]

I didn't say you could be "less careful/accurate" in a conventional aircraft -- What I said was most conventional planes give you more flexibility to trade fuel capacity for front seat weight, since both are usually carried directly above the aircraft CG.

I misinterpreted, but we are now talking about weight and balance.

 

The Cozy on the other hand carries its fuel over the CG, but its passengers ahead of the CG.

Unless the passenger is in the rear, as deronjthomas suggested, at which point the concern is the same as in a conventional plane.

 

Another option which I have heard of, but am not recommending, is to widen the canard to support the additional weight in the front.

 

Build whatever the hell you want...

Now I'm sure YOU wouldn't have appreciated that sort of response to the modifications you're suggesting in this thread.

 

...just don't make your decision based on an emotional attatchment to a particular airframe -- consider your absolute mission requirements / cost / ease of construction, and chose accordingly.

Some things can and should be emotionally influenced. Come to think of it, I never considered my mission requirements at all when choosing my wife. It's clear many have fallen for the canard type and simply want to build one. They've made their decision on gut emotion, and with blind faith and confidence that they'll be able to complete and fly -- and they are doing just that. I think a case could be made that your decision better be emotional.

[deronjthomas]

I don't mind being the first to do something different or strange. I just don’t want to make a $10,000 mistake...

[Jon Matcho]

I don't mind being the first to do something different or strange. I just don’t want to make a $10,000 mistake...

Sometimes first and different amounts to "never fly", or worse than that; death.

 

The safest thing you could do would be to build a design that has been proven many times over and modify only the paint scheme.

[Nathan Gifford]

...That would not stop him from designing, building and testing (the first time). If that were the case we would all be sitting in the grass wondering what it would be like to fly...instead we get to watch people like Mike Melville corkscrew into outer space. I'll say it again design, build, test whatever it is.

 

I guess what I'm saying is don't let anything stop you. If you want to do something, educate yourself and do it. It is that easy. (Easier said than done, I know.) ...

It took just a little engineering to get Melville into space and not everyone is capable of doing it: ask the other X-Prize losers many of whom had degrees too. You probably can engineer a 60" wide LongEZ derivative. After all the Cozy was derived from the Long.

 

However, there is more to it than just sitting down at computer with AutoCAD and widening the fuselage. Nat ran into problems with the canard when he flew the Cozy. He did not discover that problem until flight testing. Based on his flight test data he sawed his canard shorter.

 

Again you need to be sure you understand just how easy it is to take an otherwise docile aircraft and turn it into an unflyable machine. Don't let that stop you, just realize modifying an aircraft plan is not trival task.