Marc Zeitlin

I was impressed with what I saw, and I was impressed with the man from spending an hour or two with him. However, without a bunch of them flying and a lot of hours on them.... I wish them success, and hope they make it, for sure.

First of all, the prop you refer to is only for engines up to 80 HP - barely adequate for a VE if at all, and certainly not for a LE or COZY. Secondly, There is at least one other MFG of certificated propellers that has sold units to canard flyers (Hoffman), although the prop is no longer on the plane. But the certificated nature of the propeller is meaningless, since it's an engine/prop/airframe combination that's certificated, and that clearly isn't the case when using any propeller on a Rutan derivative canard aircraft. What's important is whether it's been tested and works, not the paperwork.

Yeah, but not the Vari-Prop, because they claim that you don't need a hollow crank to use it. I had dinner with the company owner at Copperstate and saw the hardware in the car on the way to the restaurant, but we talked more about the business model and development rather than the technical aspects of the design.

While everything you write is true, all the effects are pretty trivial to mitigate. A canopy cover will keep most of the heat/UV out of the cockpit and protect the acrylic - paint/lubrication of metal parts prevents corrosion, the amount of grit depends on where you are, and temperature/humidity swings are no different inside an unheated hangar than they are outside. My car is made out of metal, and it lives it's whole life outside, without a cover or me giving the slightest crap about it. I don't see parts falling off on a regular basis, and I NEVER pre-drive my car like I preflight my plane. Hardly. Even if the cost differential of hangar vs. tiedown is relatively small, the cost increase of leaving the plane out is also pretty small (repaint every 15 years instead of every 25, etc.) so it can be a no-brainer from a cost standpoint to tiedown instead of hangar if you don't have a lot of cash. I tied my plane down for 3.5 years outside in MA - rain, snow, sun, heat, cold, etc. No issues, with a cover from nose to tail on the fuselage. I've got it in a hangar now in CA in what amounts to much more benign weather, but I wanted a protected place to work on the plane and keep my tools/equipment - I'm protecting ME, not the plane. This is indicative of cosmetic filler being applied too thick and poorly. It has nothing to do with deterioration from sitting outside in UV, and everything to do with poor workmanship. Composite airplanes can live essentially forever outside as long as they've got appropriate paint on them.

Higher viscosity (larger number) means that it's thicker - more like honey than water. Generally, the higher viscosity epoxies are for warmer temperatures, but not always. The MGS epoxies have particularly low viscosities for laminating resins, which make is easier to wet out the glass. But a hair dryer with the EZ83/84 will do the same thing.

You're referring to "wheel landings", as opposed to "three point landings". There's not as much of a flare with a WL as with a TPL, but you still flare. In that one sense, it's similar to a canard landing, but so would any landing in a plane without a full stall flare. Many small taildraggers are TPL'd, however. See: http://www.richstowell.com/dragger.htm For a good description of the difference between the landings in taildraggers. As Drew points out, the landing technique for canards is a bit different than other small planes, and you do not have any of the rudder issues on landing that you have with taildraggers. In the aggregate, taildraggers are LESS like canards than nosewheel aircraft.

I cannot imagine what type of single engine 2/4 place taildragger lands remotely like a COZY MKIV or Long-EZ. Not in the pattern, not on final, and not on touchdown. I don't think you could get a larger difference. And yes, I have a tailwheel endorsement, and 577.3 hours in a COZY MKIV. Assuming you're a pilot, you'll be able to get some transition time in a canard (1-3 hours and 3-10 landings), and there won't be an issue. But even if you don't, there are techniques and types of planes you can practice in to get close.

I'm flabbergasted, David - something about canards you don't know? :-). From CP 21, or a search of the COZY mailing list archives - Boston Gear CD1145 is a cast iron gear, and D1145 is a Bronze gear that will work better than the original, but will require a bit of modification (machining and floxing).

There are a few folks that have done something for COZY's - haven't heard about anything for a Long-EZ. Ask on the canard-aviators list. Doubtful. There are bits and pieces - but not a full blown solid model (yet). Read ALL the CP's. ALL. That will keep you busy for a couple of weeks.

Depending upon where you are in Utah, I might be able to fly up and inspect/help. My airplane should be flying again later this week after a 4-5 week repair/upgrade session that has made it even uglier than it was before, if such a thing is possible. I would seriously recommend that you join the canard-aviators yahoo mailing list for extensive exposure to hundreds of extremely knowledgeable canard folks, both flyers and builders.

I wrote: This was misleading. While the cutouts are not identical, the templates apparently are identical. I have been corrected by Steve at Eureka, who has explained that the templates are identical for the LE and COZY MKIV, but due to the way that they're USED, the MKIV canard has far more glass in the spar caps than the LE does, so that the canard is, in fact both different and stronger, but the templates are the same. As long as Steve is using the templates per plans, the canards will be correct. Sorry for the misinformation.

You give me way too much credit. This is non trivial, and rarely optimized in these aircraft. There would be problems :-). At any rate, it is most likely that for the main fuselage layups (not localized reinforcements, but the main skins, both internal and out), structural requirements (stiffness, strength) were not the driving factors - damage tolerance from tools, knees and elbows was. This is at least likely to be the case for the Long-EZ, COZY, etc. - Richard may be able to address the issue for the Berkut.

In theory, yes.

You and me both. It would be relatively simple to construct one for a generic COZY MKIV - one could build one for Normal, Utility, and Aerobatic categories in about 5 minutes. But none would be official, and we wouldn't know which one was the "right" one. I treat my plane as if it's a Normal category aircraft, as that's the most conservative. Well, certificated aircraft, whatever they've been tested to by the MFG, have specific "G" limitations positive and negative. Those "G" limits, along with the stall speed and Vne (as set by the MFG) determine what the envelope looks like. So its partially based on MFG testing and partially by category limits. For experimentals, there are no "category limits", since there's no category - the "G" limits are whatever the MFG claims, if anything. I'm sure they'll appreciate that :-). This one's better, but I don't understand why Va (maneuvering speed) is where it is. I would have expected it to be at the intersection of the 3.8G limit line (bottom of the "structural damage" region) and the "accelerated stall" curve, at about 110 mph. That's where full deflection of the controls could start to cause more than 3.8 G's. You can see that the stall speed (aircraft and weight dependent) will determine Va; aircraft limits will determine Vne, but the category "G" limits and the 50 fps gust will set the Vc.

No, Mike was asking for a specific, well known thing called a V-n diagram, of which he then posted an example. It graphically indicates many of the V-speeds, but shows the relationships. I'm quite aware what a V-n diagram is. You asked as though you knew that one existed, and just wanted a copy. Since I've never seen one, I was surprised that one might exist. Had you asked for a copy of "A" V-n diagram, rather than "THE" V-n diagram, I would have said "there isn't one" :-). One would have to get design limits for the COZY MKIV aircraft that the designer has not been willing to commit to. If you ASSUME a normal category aircraft, then knowing the stall speed and Vne, one could easily construct a V-n diagram, but it's based on the assumption above - who knows how accurate that is. I base my maneuvering speed on such an assumption, however, and use 140 mph. This all assumes gross weight, obviously, and Va is lower at lower weights. PS - Your example V-n diagram is defective, BTW. It shows Vs at a load factor greater than one. In fact, for the aircraft in question, Vs is 50 KEAS, not 60 KEAS, which is why the stall speed is 97 KEAS (50 * 3.8^.5).

What V-N diagram? I don't ever remember seeing one - am I having a senior moment? All the performance charts of which I'm aware are (and have been, for 12 years) at: http://www.cozybuilders.org/performance/

I suppose if you could fly 1/2 of an Eclipse, estimating efficiency based on 1/2 of the engines needed would make some sense. But you can't, so it doesn't. The plane needs two engines to go that distance on the fuel stated, so the efficiency is 1/2 of what you state. What you're doing would be like claiming twice the efficiency for the SUV you mention, because four of the eight cylinders in the car only use 1/2 of the fuel. Makes no sense whatsoever.

Whoa. Lets look at the #'s from Eclipse: http://www.eclipseaviation.com/eclipse_500/performance/mission_profiles.html Even the best case long range trip has a fuel burn of 0.56 lb/mile/engine. And that's at an average speed of 293 kts, NOT 370 kts. You do NOT want to know what the fuel burn of these engines would be at the max cruise speed. :-). So with those #'s (from Eclipse), you get an efficiency of about 6 NM/gal (I don't know where you got the 13 from). 1232 lb/6.8 lb/gal =181 gallons burned 1100 miles/181 gallons = 6.1 NM/gal (7 SM/gal) It's not going to be better going faster :-). This also works out to 24 gal/hr/engine. Calculating these #'s for the shorter blocks gives much worse #'s - for the 250 NM trip, it's 3.8 NM/gal (4.4 SM/gal). I get anywhere from 17-20 NM/gal in the COZY, and that's with three or four seats full. With enough fuel to make a 1100 NM mile trip, the Eclipse can't take three or four folks, by my calcs. 560 kts? Where'd that # come from, for any of these planes? Vne is not cruise speed...

True, and with an EMS system that doesn't care about it's mounting angle, that's fine (I assume you're talking about the one in my plane). But... You might have wanted to check with the EFIS manufacturers before modifying your panel (and before recommending this mod to others). They all have gyros in them, and the gyros assume a vertical panel (within a couple of degrees, in flight attitude). Most EFIS's and gyro devices explicitly say that the panel must be both vertical and non-tilted (side to side - again for pointing the display at the pilot when off to the side). If you don't do this, the gyros will not read correctly (axes get coupled when they shouldn't be, at best, and the readings are just plain wrong, at worst). If the EFIS has a remote gyro system - NOT in the panel mounted box - then this could work fine, but otherwise, unless the EFIS MFG says that tilting the panel is OK, I wouldn't do it.

The FAA is not interested in hearing about your plane until you're ready to fly. You can find a Technical Counselor on the member pages on the EAA web site. You'll want one that knows composites, and preferably COZY's. If you're anywhere near Tehachapi, CA, I'd be happy to take a look at it (you don't say where you are).

Judging from the pictures, this was an AeroCanard, and although the pictures do not show an "N" number, there is one AeroCanard (N199JW) registered in Statesville, NC to John Wootton. Condolences to the pilot's family - hopefully the NTSB will be able to determine what happened so that we can learn from this tragedy.

Having someone semi-official that theoretically knows their ass from a hole in the ground take a look at your project and give you feedback and advice. I don't know if it's still the case, but some insurance companies used to take these inspections into account when deciding on insurance rates. Even more reason to have someone that knows what they're doing take a look at what YOU'RE doing.

Or: http://www.theflightshop.com/ClickBond/Click_Bond_Info.php which doesn't require registration, they carry the full line of CB's, and have datasheets.

Join the COZY mailing list, if you're not already a member. Find a local EZ builder/driver to inspect your project for quality of build. Not a problem - when you get to whatever the next step is, you'll be able to fix it with foam scraps or micro. Means nothing. The FAA doesn't give a rat's ass about bills of sale or registration with plans owners, or what you call the plane. There's no reason not to call it a COZY in five years when you get around to contacting the FAA about registering it. You don't need to do anything now. The only reason that the "registration" of the plans with either Nat or ACS mattered was to get official "support". Since there is no such thing as "official" support anymore, this means nothing. Make sure you're an EAA member, and make sure to get Technical Counselor inspections on a regular basis - at least three during the build. See above. An inspection from a KNOWLEDGEABLE builder (not some local newbie, barely ahead of yourself) is the first thing to get/do. And seriously, the engine and instrument panel are the LAST things you should be thinking about at this stage.

Absolutely. Yup. Craig explained it well. Not only aren't they much better, they're not "better" overall, at all. SOME things are better, some are worse. Overall, pretty much a wash. Stall resistance can be achieved in conventional configurations as well - go try a Glastar. The one I flew acts pretty much like a COZY with the stick full aft. The aero efficiency (all other things being equal) is better for a canard, but all things are NEVER equal. In real life, the conventional configuration has a minuscule advantage, and as Craig points out, the three surface aircraft has a theoretical advantage over the canard and conventional. Small, though. Very little of this is measurable in real life, and since the accident rate of canards is not substantially different from the rest of the homebuilt/GA market, it's obvious that whatever safety advantage canards are supposed to have is theoretical and/or ephemeral, at best. There are ALWAYS other factors :-).