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Retracts or Fixed... Opinions / Experience


cmims

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I have looked and have not seen a lively discussion of Retractable Gear (Infinity) vs fixed gear.

 

Looking for all the various opinions. Any idea of how many are flying with Retracts... How many fixed gear cozys are around.

 

Building from Aero Carnard plans #14... which I really guess means the 13th set of plans sold.

 

Carl Mims

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There are all kinds of religious and philosophical opinions about retracts. All this he-said she-said is captured in grave, oops, I mean great detail in the cozy archives on Marc Zeitlin's site.

 

Try Phillip Johnson's site for what I feel are the most rational opinions of pros and cons:

 

http://www.maddyhome.com/canardpages/pages/plmjohnson/index.html

 

...Wayne Hicks

Wayne Hicks

Cozy IV Plans #678

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

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I agree with Wayne. There is a lot of zealotry on the lists. The concise, rational argument is on Phil Johnson's site. Sadly, there is not enough actual, reliable data to make apples-to-apples comparisons of FG/RG performance on a Cozy. There probably won't be any notably useful data in the near term since most of the RG Cozys in the pipeline have engines that are non-standard and therefore difficult to compare with the fleet at large.

...Destiny's Plaything...

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Originally posted by cmims

I have looked and have not seen a lively discussion of Retractable Gear (Infinity) vs fixed gear.

If you stay here long enough... a lively discussion on this topic will soon hit you in the face, so to speak.

 

Try these threads here #135 and #625.

Jon Matcho :busy:
Builder & Canard Zone Admin
Now:  Rebuilding Quickie Tri-Q200 N479E
Next:  Resume building a Cozy Mark IV

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  • 2 weeks later...

The spar gets the most treatment. I would do the gear between the spar and the stake plans. There are hydraulic lines and additional layups involved as well. There is a complete wheel cavity enclosure that comes with it that is definately post spar.

BTW..I hope your main focus is on how the retracts (infinity alias JD) are more suited to sloppier landing sites THAN the plans gear.

The speed and coolness factor have to be a "given" because nobody has yet to publish the findings on either one. All pictures of "full" retract Cozys are on the gear (on the ground). I would saw the gear off of John's plane for the educational factor, but I am afraid he would not allow it. Besides, as fast as he taxis, I would have to do a Keanue Reeves " Speed" re-enactment to get the job done and my toes would doubtless become much shorter in the process. So I will have to wait till somebody actually flies retractably....

Till then we must all wait patiently and hope JD sees the price of his gear some day and says "OOPS! it's too high! I meant 2600$ not 5600$"

I'm not holding my breath though, he is from California and is quite proud of his product. Like many other things in California, there is only one and the competition is still years behind (or in line to pay).

If you wish to see the coolness factor, take a picture of a Cozy in Flight and smudge away the gear with a photo editing program. It won't tell you how fast it can go, or how it lands on a grass field but it will show you the "coolness" factor. Sometimes, that and $5600 will be all that it takes.....

;)

Back to building... #618 Cozy MK IV

 

My Cozy web pages, courtesy: Rick Maddy... :cool: WN9G :rolleyes:

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The video he sent me only has the yellow Long EZ with the retracts... does he have a video with Cozy's now?

 

The video I have also shows a drop test of the Long with the fuel tanks fulll of water (heavier than fuel). Its not a very high drop, but you can tell its heavy and it bottoms out the gear travel. Looks stout to me.

 

But as I and others have said before, the price you pay and what you get (two arms?) seems to be a broad spread. I may try to sneek a set home by not letting the little woman see this year's Summer bonus. Then again I may just be calling featherlight... :rolleyes:

This ain't rocket surgery!

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CNCDOC

 

Not sure exactly where you are coming from... Refering to safety as in Gear up accidents, or the benefit of the shock / strut movement on a hard landing or better for off field landings or ditching in water with gear up.

 

Speaking of hard landings... Saw a Velocity land hard at Sun-N-Fun... on Saturday...came in flat.. did not have any flair.. hit hard.. bounced about 10 feet and went around.. Pilot did not realize that he had hit is prop.. took about 6" of each of the 3 blades. The whole approach looked squirly

 

He came back around and landed safely... parked in the homebuilt display area. He quickly ran off to get someone from Velocity to come look at the plane. I did not want to bother him at the time.

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  • 1 month later...

:feedback: OK, Let's assume for a moment that you have decided to commit to retractable main gear. There appear to be two basic systems: 1) the "Infinity" style with the gear attached to the main wing spar and swing inwards to the fuselage and 2) the "E-Racer" style with the gear mounted in the fuselage and swing outward into the wing. What are the "pros" and "cons" of each?

 

Here are a few I thought of:

"Infinity" style frees up volume in the fuselage for a fuel sump to recover and/or add to any fuel volume displaced in the strake by the gearwell. "Infinity" style has potentially <slightly> "cleaner" installation: does not have the "bulge" or "blister" covering the wheel that does quite fit completely into the wing/strake. "Infinity" is more complex - oleo strut vs. composite strut. Possible structural considerations in wing spar. $$$? does anybody know the cost of the E-racer gear? Weight? does anybody know the realtive weights of the two systems? Other considerations or thoughts? Other possible system configurations?

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The E-racer gear would go a bit toward Nat's concerns about putting u/c loads on the ENDS of the main spar, where he didn't want them to be. I don't know what the mechanism would be like but would it impact on the arrangement of the rear seatback?

 

Either way you are boldly designing in the strake, the pictures I've seen of the arrangement of ribs in the strake for the infinity look like a rat's nest.

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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...uuhhmm... I think the E-racer style would not be putting loads on the centersection spar since it's hard points are in the fuselage... :confused:

 

But, you're certainly right about unknown changes to the rear seat back.

The E-racer retract mechanism occupies a space from the firewall to roughly14" (guessing from looking at sketches/pictures of the E-Racer) forward. Some of that is also occupied by the wing centersection spar. What's the distance between the firewall and the Cozy seat back at the top of the center section spar and the distance at the bottom of the seat back?

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IMHO, retracts are NOT worth the effort. I admit, they look "cool" . But the speed benefit, 15 - 20 mph more.... Not worth it. I am assuming that there is a weight penalty as well. Plus, you carry less fuel right.

+20 kts is a good thing :D and truth be told in the final analysis the coolness factor is going to play a BIG role. The rest of it is rationalization. There is a long list of issues: time to build, weight, $$$, etc., etc. But when all is said and done are you gonna say to yourself "wish I'd spent the extra time and $$$ to go that last little step"? Not everybody is going to want to put the extra time and money into it. (any problem can be solved with enough time and money :P )

 

I suspect you don't have to sacrifice total fuel volume. just put it somwhere else. The "Ifninity" web page addresses this. ;) but let's assume you're willing to pay the price in terms of $$$, and usefull load. I'm trying to think through the installation precess, and see what all gets hit by the "domino" effect. You know: you change one little thing and a dozen others need to be changed also. Some of them unexpected. For example, I had been thinking that the E-Racer style gear would be simpler untill it was pointed out about the unknown (at this point) impact to the design/installation of the rear seat (and that one should have been obvious :o ). The great benifit of talking about it on a forum like this one is all the different people looking and thinking about it. and, yes, even throwing rocks at the idea.

 

I have plans for a retractable gear from long, long ago for a CA-65. It's totally mechanical (or electro-mechanical) and built with "off the shelf" gears, springs and 4130 tube. So, I'm still mulling that one over too.

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"...would not be putting loads on the centersection spar..." erm yeah, that's what I said...

 

More than anything the idea of TWO independant retraction systems gives me the horrors. Both down for landing, both up for flying, one up one down for parking. The odds against reliably picking the right arrangement seem insuperable.

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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"...would not be putting loads on the centersection spar..." erm yeah, that's what I said...

 

More than anything the idea of TWO independant retraction systems gives me the horrors. Both down for landing, both up for flying, one up one down for parking. The odds against reliably picking the right arrangement seem insuperable.

 

That reminds me of a true story about a wealthy Doc. at the little airport where I learned to fly. This gentleman went out and bought a Lake anphibian and proceeded to land gear up on the runway at my little town. He had the airplane repaired and then landed gear down in the water at the local sea plane port. Contender for a Darwin award? Well, it didn't kill him but still, how would like to have this guy operate on you?

 

"check gear down and locked" should be a prominant landing check list item :)

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I had the honor of meeting AVM Wrigley once, he completed the first circumnavigation by air of Australia in a Fairey IIId. Story goes in later years he was flying a later seaplane at Point Cook where there are a landing area and an adjacent seaplane dock.

 

The PO in the back keeping an eye on the senior officer pointed out (somewhat nervously) that Wrigley was on final for the grass strip which was bad in a seaplane. Wrigley went around and landed in the bay then (while climbing out) gave the PO an earful about how much time in seaplanes he had and how wasn't going to land on the grass. He then jumped down and plunged in 3m of water...

 

Was looking at the Spencer TriGull a while ago. With flaps, and retractable tip floats and undercarriage, you would have to be REALLY particular with your checklists.

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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  • 4 months later...
  • 1 month later...

JD from Infinity say's "YES". SSSSSOOOOOOO, Guess what I got planned for them cccoolllddd winter months here in OHIO land!!!

 

I got a brand new pole barn, insulated, heated, water , electric, that I built last winter JUST FOR THIS OCCATION.

 

KEEP WARM

 

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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