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a 250 Knot Long EZ


airwrench
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I am finishing up the initial stages of my long ez project. I have the bulkheads complete and waiting on the sticks for the fuse. I am interested in speed mods in an effort to acheive a moderately fast aircraft capable of withstanding cruising speeds in excess of 250kts. (the engine part is simple, I just want to know what structural mods would be prudent to implement in regards to the increased speed)...............waited too long for the infinity, which don't seem to be getting off the ground:(

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  • 1 month later...
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Newbie question here!

I am about to start my Long / Berkut project and am after basically the same thing. Speed! Could you also substitute the cozy wings and spar (since this is all new construction) and make the spar to the EZ dimensions and then carbon both? Would this change a lot or be more stabil in flight than the Long EZ wings?

Just curious (and now putting on fire suit):scared:

Press On

Tom

"Time flys when your building"

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Your questions are beyond my technical expertise, but I don't have a lot of faith in the above ideas either. I am not aware of any evidence there is anything deficient in the strength of the airframe or that this is the speed limiting factor. There are plenty of fast aircraft out there all fg. I am not convinced substituting cf for fg will (by itself) create a stronger structure.

 

I do understand the limiting factors are airframe flutter and performance of the canard. These problems may be overcome by re-design. Don't know how to go about it.

 

Remember this is a very efficient cross-country touring aircraft you are considering hot-rodding. On completion you will not have a particularly useful aircraft.

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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Yeah, the engine part is simple - just get an IO 540. Extend the fuselage a foot and move the pilot and passenger forward. Make the wingskins and spar caps out of carbon. Be sure to use a good pair of wheel pants and gear leg fairings.

Gee ... sounds like a Berkut FG :-)

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  • 2 weeks later...

I'm new to your organization but has anyone considered the Innodyn 255 hp turbine at 188 lbs instead of the IO-540 hp at 390 lbs ?

I'll be happy to consider it when Innodyn delivers their first engine.

 

That would be sometime after the sun goes dark.

 

If you want to talk about a turbine engine that actually exists, we could talk about a 250 C-18. There's a guy that's just put one on a Cozy, with a custom gearbox. Very interesting. Or there's the Deltahawk, which has a good shot at delivering a batch of engines to it's first buyers, and might even be viable long term depending on the market in general.

 

Innodyn is vapor.

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I'll be happy to consider it when Innodyn delivers their first engine.

 

That would be sometime after the sun goes dark.

 

If you want to talk about a turbine engine that actually exists, we could talk about a 250 C-18. There's a guy that's just put one on a Cozy, with a custom gearbox. Very interesting. Or there's the Deltahawk, which has a good shot at delivering a batch of engines to it's first buyers, and might even be viable long term depending on the market in general.

 

Innodyn is vapor.

I am with you on that one, a lot of smoke from innodyne but not much else.

As far as efficiant turboshaft engines are concerned-------heck, that deep in one might as well turbofan it!! Any way you go there will be considerable $$ to make it happen, but then again one could go with the 20B and throw on a couple turbos and "walla"........a seven hundred horse bomb.:scared:

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Deltahawk's not a turbine, it's a diesel.

 

If you go looking to stuff a turbine in a Long EZ eventually someone will try to sell you on a converted APU (which is what the Innodyn prototype is). Don't do it.

Yes, I know deltahawk is a diesel....turbo/supercharged I do believe. It is supposed to run on a variety of fuels as well, I have followed them for a while and.........like cont./lyco.........they are genuinely expensive:envy:
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Have you checked out the price of carbon fiber recently? I see quotes that it's "3 times the price of fiberglass". Ha, not even. There's a worldwide shortage of carbon fiber. Multiply by 10, at least.

Wow, is it that high? It's been about 4 years since I've bought any in quantity, I had no idea. I've been thinking it was in the range of $25-35/yard - sounds like I'm out of date.

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  • 4 weeks later...

Hi guys and girls,

Im new around these here parts :o but I have been lurking reading a number of posts.

The idea of a 250kt cruise speed is certainly a stretch target, but just the sort of things to get people thinking and their creative juices flowing. It would seem that most of us automatically start to think of the design innovations introduced with the Berkut a decade ago (carbon this, carbon that) and I suspect that is part of the solution.......... but I do think it's going to take more than a lot of thrust (engine and prop' design), a slippery aircraft design (these canards are already slick), and reducing all the parsitic drag you can think of.

As Spodman correctly pointed out, the next big hurdle is most likely looking into the aerodynamic constraints (such as canard flutter). Like Spodman, Im not in a position to provide informed and precise aerodynamic consultancy services, but what about thinking in this direction.......... what is the fastest (non-military) canard about? One of the larger commercial derivitives perhaps? What canard designs have they incorporated, and what is the relationship with it's primary wing (how does that compare to the standard Berkut/Longes design)?

I think threads like this may be just what get's some people interested in experimental aircraft............ experimenting. Now I know some of you are thinking this is a serious business, flying, and I totally agree (yes, aviation maintenance and engineering background here). This thread is about navel gazing, thinking of the 'if only' thoughts, and giving some direction to some dreaming going on out there.

I don't think that what everyone is seeking is a very efficient cross country touring aircraft, some people do like the hotrod (why do you think they chose to build Berkuts).

The Variez and Longez inspired many people and indeed their designs/modifications, just perhaps they have some more inspiration to provide.

I look forward to your replies, flames, but most importantly your thoughts about the 250kt Open-ez ;)

 

Cheers,

 

Bruce.

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One thing to consider is:

 

- Canards have currently quite thick wing profiles.

- thick profile = more drag

- it is thick because of the strength required and it is achievable only with

a thick profile if glass is used.

- with carbon it would be possible to use thinner profile

- with increasing intentionally the lift of the fuselage, maybe the wing span could be reduced a bit too.

- the Eppler 1230 mod is a thick turbulent profile and propably quite draggy (haven't tried to simulate it or anything), a person like John Roncz would be capable of designing a new less draggy laminar profile for a replacement I am sure.

 

In a very draggy airplane, the wings create something like up to 60% of the drag of the airplane. Replacing the profile with a faster one, which would be better optimized for the higher cruise speed.

 

With the current profile, adding power does not help much. For example Cozy-Jet isn't very fast compared to how fast a jets usually are. If the drag of a profile increases exponentially above certain speed, you could be using a Saturn-V rocket engines and still be slow. I am quite convinced that making the plane faster, requires to change the wing profiles, in addition to making the fuselage etc. smooth. Small optimizations help a little, but new wings and canard could help significantly (IMHO).

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I heard a nasty rumor that the cost to peek under the ultra-slick cowl of Klaus' Vari (and it's associated super low drag cooling system) was a firstborn son, indentured servitude sanding parts, and a left...er...leg, I doubt he'll let anyone short of Burt himself in on the details of his new wings.

 

Of course, being a nasty rumor, it might not be true.

 

:D

 

-dave

This is not a sig. This is a duck. Quack.

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That's very interesting! Do you know if he is considering the inclusion of flapperons/flaps to accommodate TO and Landing speeds?

Do you know if he has any designs he wouldnt mind someone looking over?? :rolleyes:

I don't know if he's including flapperons, but I'd bet a lot of money against it.

 

If it were me, and I were willing to bet my life on untested wing mods (I'm not, I've got a little girl that I want to watch grow up) I'd look at Ilan Kroo's work on the C wing. I mean, if you really want a few extra knots that badly, there are worse things that you could bet your life on.

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"Cozy-Jet isn't very fast compared to how fast a jets usually are. "

 

----> Greg won't exceed the published Vne because of control surface flutter. So, he can't utilize all that power yet. He is working with the EZ jet folks and is building new elevators and ailerons. I haven't spoken to Greg in a while, but I heard rumors of new carbon wings and canard too? Anyway, he expects the new "airframe" will have a higher Vne that will allow him to put to use some of that excess power the engine is capable of generating. He's gonna go ALOT faster.

Wayne Hicks

Cozy IV Plans #678

http://www.ez.org/pages/waynehicks

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Ha

 

I have the standard original GU Canard. If I could push mine up to 250 Kts. I'd have to remount the canard incidence to -20 degrees just to keep the nose down. As it is I have to hold down presure on the stick at + 170 kts and that's in a dive.

 

The only good thing a 600 hp LEZ could do would be STO. I removed the landing "L" part of this formula as it would not shorten the landing.

 

Remember the faster you go, you have to have some way to get rid of lift on the canard. The same basic principles would apply to a 600 hp Piper Cub.

 

My 2 cents

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