Marc Zeitlin

For aircraft plans sold by companies no longer in business and for which no copyright owner can be found (or who has given up the rights to the copyright), have at it. For the COZY MKIV, owned and sold by ACS, you're restricted to the agreement you sign with them. Al neither has nor needs permission, since he's not selling COZY MKIV plans, but only parts. Only the plans are copyrighted - nothing in any of these planes is patented.

Give me a clue what "fuel leak issue" you're talking about. No and no. MAYBE using some fuel cell foam in the tanks might be useful, but given the relative paucity of evidence of fuel tank fires (the few canard aircraft fires have been engine compartment fires, not tank fires in the air or on the ground, and there have been no "explosions") there's no evident issue with the construction of these aircraft's fuel tanks. Posting a reference to what you're talking about will help others respond in a useful manner, rather than having to guess what you're talking about.

Kent buried the lede :-). If you're building a COZY MKIV, you should join the COZY mailing list at: http://cozybuilders.org/mail_list/ read through the whole http://cozybuilders.org/ website, as well as all the links that Kent pointed you to, particularly Wayne Hicks'. Then read through all the presentations at: http://cozybuilders.org/Oshkosh_Presentations/index.htm many of which will be repetitive, but there's a LOT of what you asked there. Plan on changing as little as possible, within reason, unless you're interested in having your kids be fully grown before you fly it :-).

Were you to bring that plane to me for a Condition Inspection and we found that crack in the bracket, there is no way I would sign off the CI, which says that the aircraft is "In a Condition for Safe Flight". Were I to see that crack on a Pre-Buy examination, I'd tell the buyer not to purchase the plane until it was fixed, or ensure that the plane was trucked to a place where it could be fixed. I'd tell the seller not to fly the plane until it was fixed - maybe ONE flight to the place of repair, but that's it. Landing gear collapse, which is what a failure of that bracket could lead to (however unlikely it may be, and given the crack, it's not ALL that unlikely) can be a catastrophic event. Land hard, hit a small pothole, etc...

That's a Hertzler prop.

Well, I wouldn't say "obsolete", as Kent says - just sub-optimal. Thousands of canards have the old plain bushing style NG-6, and if installed correctly and adjusted on occasion, they work fine. Tapered roller bearing is better, but expensive. Pays your $$$ and takes your choice. Agreed - a close-up of the pic you posted shows a raw nose gear strut with no torsional wraps - you can't see any weave; it's shiny; and there's no peel ply texture. This is a clear indication, in my opinion, of the intensely sub-standard and unsafe work that Mr. Hanson continuously cranks out. That said, the nose gear strut is <$100 from Aerocomposites, and the upper and lower castings, as well as the NG-3/4 are easily salvageable. Heat and a hammer will break them free of the strut, and you can grind out the residue. Or just grind the strut out of the castings, since you're not trying to save the strut. Actually, for bonding, JB Weld is probably superior to flox in a laminating epoxy - the bonding strength is higher. No one in the industry uses laminating epoxies for bonding - various Hysols are common bonding agents, and JB Weld is in type of family. So that was the least of the issues with the nose strut assembly - really, the only issue was that the strut wasn't wrapped - if it had been, you could have easily lived with the JB Weld and older style NG-6.

No, that's not at all what I'm saying. You have a horizontal surface relationship to CG that needs to be maintained (CG forward of Aerodynamic Center) in order to have static longitudinal stability. However it can't be TOO far forward, or else the airplane becomes unable to rotate for takeoff, and TOO stable in pitch to the point that you lose maneuverability. You also need to have an equivalent vertical surface relationship to the CG in order to have lateral stability. Read up on aircraft stability requirements and calculations. Moving CG forward might address the lateral stability issue, but completely screw up the ability of the aircraft to get off the ground and be maneuverable once it does. Everything is a balance, but having as much vertical area at or forward of the CG position (about where the pilot is going to be in one of these planes) is going to make the plane want to fly sideways or backwards, or at least be happy to do so if it happens to be perturbed in that direction. I suggest googling "aircraft design book" and purchasing a number of the ones that come up - Raymer's is good, as is Roskam, just for starters. Also "Perkins and Hage" for "Stability and Control". You cannot design anything other than a standard looking aircraft (think C-172 or Piper Warrior) using "that looks about right" techniques. Particularly with canards and/or tandem wing aircraft.

Are you talking about a horizontal stabilizer or a vertical stabilizer? Vertical surfaces forward of the CG (as any vertical surface attached to the canard will be) are destabilizing in yaw, and would require substantially larger tail vertical surfaces to offset. The vertical (or at least partially vertical) surfaces attached to the wing tips are not far aft of the CG, and will have only a very weak stabilizing effect, particularly due to their small size and cant angle. While interesting looking, this configuration, even with a vertical tail at the aft end of the fuselage, would have poor directional stability at best, and be directionally unstable at worst.

Eureka uses a CNC hotwire machine - it's still hotwiring. Steve does not machine the foam. Accurate, but hotwire, nonetheless. I'm at a loss to understand the belief that fabricating ailerons is rocket science - building a set of new ailerons, if required, should take a long weekend - maybe 3 - 4 days, just because there are about 4 serial cure cycles. Two skins, end ribs, and some reinforcing. Use 7/16" steel rod or tubing to put lead weight inside, and ensure good balance. It's just NOT that hard.

The balance pic you show is from page 7 of the aileron addendum. Look at page 5 - there are two templates that show WL's and external skins. You can use these to create an external level "jig" for determining the WL. In any case, if you balance the VE ailerons so that the top skin is closer to level than the bottom skin, you're good. And that's after ALL paint.

Sand all the paint and excess fill off and repaint it so that it balances correctly. Put the minimum amount of fill, primer and paint on, particularly on the bottom which never sees UV exposure - NEVER paint control surfaces over old paint without removing it. Only then, if the elevator is not in balance, add extra weight, and then only outboard.

So if you need to install something on the centerline of the airplane underneath, then you're going to need to get rid of the NACA scoop entirely and go to armpit scoops under the strakes. Otherwise, you'll melt your engine, as Kent indicated.

Extremely bad idea, and almost guaranteed to screw up any cooling air into the engine.

There are many factors that can lead to high temps (you don't say what your CHT's or oil temps actually ARE, which would be useful for people trying to understand what you think a problem might be). What makes you think that the air intake is the cause of the high temperatures of whatever type you're seeing?

What do you think is wrong with what you have?

Yep. I think folks do it to keep away the tire-kickers, but I agree it's counterproductive. Last I spoke to Don/Brendan, they were asking $90K. I told them they'd be lucky to get $60K, which obviously is not something owners want to hear. The other thing to note from that ad is that it's ancient - they discuss the plane needing an "annual" (no such thing - it's a Condition Inspection, but old habits die hard) in 11/2017.

That's Don Ponciroli and Brendan Woolrich's plane. Almost never flies, way overpriced, needs work and mods. Could be a good project plane if priced reasonably. I've told Don they're asking way too much - maybe they've dropped the price in the intervening years... I'd be extremely concerned about the engine (corrosion), since it lives right on the coast and even though hangared, is almost never used and not pickled. While I don't do this in my Pre-Buy's (I don't take apart other folks' aircraft), in this case I'd want to pull a jug (LOTS OF WORK) and take a look at the cams and rest of the interior, as well as just bore-scoping the cylinders. And while this is not the latest version of what I use, it'll give you an idea (for a generic canard aircraft) of what I look for in a CI or PB: http://cozybuilders.org/docs/Canard_CI-PB_Checklist.pdf

No. It's not for sale yet - I'm just projecting that it may be sometime this year. Don't know for sure. Dave will have a more comprehensive list of LE's for sale, but you'd still need a good Pre-Buy examination. I keep a list of all COZY's for sale (that I know or hear of). Which plane is this? It's doubtful that I'm not familiar with it... See: https://www.burnsideaerospace.com/pre-buy-examination-information and page 32 of: http://cozybuilders.org/Oshkosh_Presentations/2015_Zeitlin-Soup_To_Nuts.pdf for information on what to look for. But the most important thing is to have someone that knows their ass from a hot rock look at the plane, and just because someone has built and flown one or two of these planes doesn't necessarily mean that they are in that category. I've seen a lot of crap that supposedly knowledgable builders had let slide or just missed. See: http://cozybuilders.org/mail_list/ for COZY mailing list information.

Get in touch with Tim Sullivan, who bases his Long-EZ at Placerville. Great guy. I know of a very nice Long-EZ that might be for sale - the owner hasn't flown it in over a year. Get in touch with David Orr who maintains a list of all Long-EZ's (and other canards) for sale. I maintain a list of COZY's for sale. Join the canard-aviators mailing list, which has over 1500 members and is pretty active. If you're interested in COZY's, join the COZY mailing list, which has over 800 members, 100 flyers, and 300 builders.

So let's review this. A claimed empty weight of 535 lb. is extremely suspect. The lightest VE I know of (granted with an O-200, but that's not going to make a 90 lb. difference) is about 610 - 620 lb. Most are in the high 600's / low 700's. So when someone says that their airplane is in the 0.001th percentile of weight, there should be a LOT of skepticism. 635 lb. I could believe, if the build was really high quality. But I'd be a LOT of $$$ against 535 lb. Not having logs means that anything anyone says about the plane is meaningless - there's no record to back it up. You don't eve know what you're trying to verify at that point. For a VE owner to not be aware of the wing spar joggle issue and the wing spar attach corrosion issue means that he's not paying any attention to the notifications put out by RAF. That's not a good sign. Did he at least know that the plane is restricted to +2.5G / -1.5G? There is certainly nothing wrong with kicking the tires and looking at the plane, but unless YOU are a canard expert and know exactly what to look for, how to do a Pre-Buy examination and what to measure/ask, I would HIGHLY recommend that if you're serious about the plane, you get a canard expert to perform a Pre-Buy examination for you. Knowing who did the last 5 - 10 Condition Inspections and what maintenance was done on it would be extremely useful. Is the plane in CI now? Can it be demo flown? Does the owner have dual jacks so you can check the landing gear attach points? A million other questions... See: https://www.burnsideaerospace.com/pre-buy-examination-information for what a PB exam actually entails. Given the known corrosion and spar cap issues surrounding VE's, I STRONGLY recommend to my customers that they consider Long-EZ's instead. My $0.02.

If you missed my warnings on the COZY and canard-aviators mailing list, be VERY careful with anything that David Hanson has worked on from a structural or aerodynamic standpoint. Caveat Emptor.

Just out of curiosity, why would X-Plane have changed the flight modeling engine in such a way as to break a previously working model? What did they do?

Curt is 120% correct here. We were trying to use this model for some simulation wrt the development of a new avionics package, and it was a total POS - didn't act like a real LE in any way, shape or form. We wasted a lot of flying hours finding this out... Gaming model at best - don't even think about using it for training. The new link is here: https://www.vskylabs.com/vsl-rutan-longez if anyone wants to see it, for no good reason.

Who did the pre-buy examination, and how much does it weigh as-is? Are you going to switch from cuffs to vortilons?

a) Yes. Flies fine with WAY worse - just might leak a little air. As long as the hinges are intact and not loose, there's no issue. b) Not going to work. And these canopies changes shape substantially with temperature changes - when it's cold, they "banana" up, due to the differential CTE's of the fiberglass and acrylic.