Marc Zeitlin

Holy crap - 1.5 IPS is "shake the teeth out of your head" level - I would be extremely concerned with the integrity of the structure, engine mount, and control systems on that plane with that level of vibration. Since you have a Dynavibe, it should be possible to add weights to the prop/flywheel appropriately to get that level down below 0.1 IPS - preferably around 0.03 IPS.

It hasn't been done on canard ailerons - no clue about anything else. On our canards, generally the wings are stiffer than the canard, but that's dependent upon which model you're talking about. And yes - the outboard MB is what does most of the work wrt flutter - experts to whom I've spoken indicate that the inboard MB on the canard elevators isn't doing much at all. Not that it can be removed, but that flutter resistance mostly comes from the outboard MB. So you are not mistaken - hence my comments above, but @Patrick knows best.

Every Varieze, Long-EZ, Berkut, Velocity, E-Racer, COZY III and COZY MKIV on the planet, so, yes. They all have elevators with both an inboard and outboard mass balance weight. Non-optimal, per folks that know a lot more about flutter than I do, but that's what they all have. Any flutter that has occurred (and it has, a few times) has been first order bending, not higher order torsion.

You were fine up until the last phrase. Yes, all that you'd be doing to a plane that was previously registered and flying would be a major change, and would require a 14 CFR a Part 91.319(b) re-compliance period (commonly referred to as "going back into Phase I", and in fact, called exactly that in the latest version of FAA Order 8130.2K) but unless you are intentionally misleading on the paperwork you submit to the FAA, you cannot be the "builder of record", because you did not build the plane and it already had an AWC and registration. You can certainly re-register it and get a new AWC, and while you can claim that you're the builder and it's very unlikely that the FAA would be able to determine whether you were or not, that doesn't change the legality of the situation. Just a warning. Get the airframe, modify it as you desire, get a new AWC and registration if they're expired, and do anything you want to the plane, as is your right. But you cannot legally claim to be the builder nor can you get the repairman's certificate for it if one has already been issued. And realize that however unlikely it is to be caught, lying to the federal government on official forms is, in fact, a crime. The only thing you'll be missing out on by not having the RC is the ability to sign off the Condition Inspections yourself.

Oh, well, yeah - you don't want an IVO for many reasons. They have had many failures, but it's not because of the # of blades they used. They're terrible designs, IMO, both from an aerodynamic and structural standpoint, even if the actuation mechanism for creating and changing blade twist is very clever (although backwards to what's needed aerodynamically).

A few things going on here - while a 2-blade prop has blades that pass through the wake of the strakes more closely together than do the blades of a 3-blade prop, they're not simultaneous, since the thrust line of the engine is well above (8" or so) the TE of the strakes. The vibration signatures are definitely different - a 2 blade prop has a much lower fundamental frequency, so ANR headsets work better with 2-blade than with 3-blade, and the plane's a bit quieter inside the ANR headset. Not a huge difference, but noticeable. There are at least two MFGs of 3-blade wood or composite props for canards - Catto and Performance Props (although I don't recommend the PPs, as they're really loud and have a historically higher failure rate). And who was that MFG? Hard to evaluate their claim without knowing who they are...

Both 3 and 2 bladed props work fine. There are some subtle differences, but basically, the performance and safety is the same if they're built well by reputable suppliers. Personally, I like 2 blade props because they're cheaper, easier/cheaper to ship, easier to keep clean in the exhaust stream, easier to track, THEORETICALLY a bit more efficient (although you'll never measure that in use) and generally lighter. AFAICT, the only advantage to 3 blade props is that they look cool. Catto's 2 and 3 blade props are bulletproof, although I wouldn't get the nickel leading edge - I don't think he's perfected the adhesive bond, and there have been instances of blades throwing the LE. Just get the urethane LE. For EZ's, the Persson props (used to be Hertzler Silver Bullet) are excellent 2-blade props and are what I generally recommend (and have on my plane). Catto props are composite, in that the glass is a structural element. The Persson props have a composite wrap, but it's not a structural element. Basically, in propeller theory, you add blades only if you cannot get the power absorption capacity with fewer. But aesthetics seems to drive a lot of what happens.

Uggghhh. Sucks, Zach. Big job. Temporarily, just so you can keep flying, try to pop the broken bit down so that it's flush with the rest of the canopy. Then use plexiglas cement (very thin liquid) and dab it into the cracks, and stop drill the end of the cracks. Then cover any small open spots, if any, with some tape on the inside of the canopy. Luckily, you rarely try to look straight up, so these cracks shouldn't prevent you from being able to fly the plane safely. For a permanent fix, you'll have to build jigs, cut out the current plexi, and reinstall a new canopy cut to fit, re-layup both the inside and exterior layups, and re-finish. Like I said, big job. Contact: https://www.airplaneplastics.com/contact for info on obtaining a new canopy. They still make Long-EZ canopies, I believe, and MAYBE they'd be willing to sell you only the forward 1/2, since that's all you need given your split canopy. Good luck.

This is good as an auxiliary heating methodology, but it doesn't keep extremities warm (socks, gloves). I have heated seats in the plane, and they're nice, but my feet would still freeze if that was all I had. If one plans carefully, all the electrical connections for electric socks, gloves and vests can be in an armrest, so only one simple and accessible plug is required to connect to the plane. Still craploads simpler than any of the other methods, and unlike motorcycles, there's no wind with which to contend, so far less juice is required to stay warm.

An alternator does not put out enough power to create any appreciable amount of air heating. A 700W heater (low power space heater level) would require all 60A from a 60A alternator, leaving 0 for anything else. If a canard aircraft doesn't have heat, you have three options, AFTER you seal up all the air leaks (because if you don't do that, no amount of heat addition will help). Install a heat muff on the exhaust and run a SCAT tube through a valve into the cabin (bulky, but works and relatively cheap) Install an oil cooler in the cabin and have an alternate oil supply to it (complex, heavy, but can work well - it's what Velocity does) Get some heated motorcycle clothing and wear that when it's cold (cheap, simple, no aircraft mods other than a couple of AUX power outlets

You know best. Good luck.

And what I'm telling you is that in hundreds of other installations, deterioration of the teflon tubing does NOT occur and I've never heard another report of it occurring in 20 - 30 years, with tens of thousands of hours of operation. So the chances are good that the issue, whatever it might be, was specific to YOUR installation. Could be a material problem (wrong material, defective material - don't know) or an installation problem, or some particular issue with YOUR plane, that occurred on no other plane, that exacerbated wear. So you can discount my comments all you like, but the lack of ability to imagine something is not evidence for it's lack, and the historical evidentiary data supports the use of teflon hinge pins without deterioration, and not only on canard aircraft. While you may be reducing the total weight of the control surface, that's not the only determinant of flutter susceptibility. Reducing the weight is always good (in a vacuum - all else equal) but if in reducing the weight you increase flutter susceptibility due to the other design changes made, then that's a bad thing. Niether "Thoughtful" nor "reckoning" are engineering terms and they have no bearing on whether the flutter margin is increased, decreased, or remains the same and flutter is not an intuitive subject. Lower weight, Lower MMOI, high stiffness, proper/optimal mass distribution - these are the things that increase natural frequency and increase flutter margin. You've helped in one area, but possibly hurt in two others (MMOI, mass distribution). And what I'm telling you, though not a flutter expert by any means myself, comes from folks that are flutter experts. The weights inboard do little to resist flutter so the fact that you've moved substantial weight inboard, although the average balance (inboard/outboard) of the aileron may be the same, could have a deleterious effect on the flutter susceptibility. While other airplanes do have a single balance weight, as you point out, it's almost always near the tip of the control surface - not inboard. There's a reason for this. And that single balance weight is the total balance weight - it alone balances the control surface, without a 2nd inboard balance. Remove your inboard balance weight, which is not necessarily contributing to flutter resistance, and the aileron would not be totally mass balanced, which then does contribute to reduced flutter magin. Had you put a single balance weight at the tip of the aileron which totally balances the aileron (If such a thing is possible while still maintaining full throw) I'd be substantially less concerned about the modification, and it might even increase the flutter margin (which is already pretty high) over the stock, distributed system. But only testing will determine any of these things. Since you're in Germany, where you have to (in my understanding from discussions with other German builders/flyers) justify any modifications made from the plans, I'll be interested to see what they say if you stick to this particular modification. If they don't care, then the only issues will be the safety/flutter margin ones. You may dismiss these concerns if you like, but they are real.

First point. I've NEVER seen any wear on ANY of the LEs or COZYs on which the teflon hinge pin kit was installed (including over 1800 hours on my own COZY MKIV). As soon as the teflon is installed correctly, wear ceases (to any measurable degree). So, I cannot imagine why your installation barely lasted and needed replacement - I suspect an installation problem. This is an extremely worrisome modification. The continuous LE mass balance is known to work and there has (to anyone's knowledge) ever been any aileron flutter on any Rutan derivative canard aircraft that uses this design, including very high speed and high altitude Berkuts. Here are the concerns: Discrete inboard mass balance weights (as on the elevators) have very little effect on flutter margin - hence the admonition in the plans to ONLY add weight to the elevator outer mass balance, if additional weight is needed to balance the elevator. I've been told by flutter experts that the elevators would have had far higher flutter margin if either a distributed weight system - like the ailerons - was used, or if all the weight was outboard (as is usually the case on conventional aircraft elevators and rudders). So the fact that you've changed to a less effective flutter prevention system is problematic. Your engineer friend is right to be concerned about MMOI - aside from mass distribution issues, as described in (1), increasing MMOI lowers the natural frequency of vibration, (due to "sqrt(K/M)" similar effects) and this also lowers flutter margin. Lance Hooley's Jet "Long-EZ like" aircraft's fatal crash due to apparent wing flutter is an example of what can happen when adding mass and changing MMOI, as well as changing the lateral mass distribution. There are many areas of Long-EZ aircraft construction where weight could be saved. Modifying safety critical flight control surfaces in order to save small amounts of weight, without the engineering background to determine if such a modification is either warranted or safe is contraindicated. Comparisons to aircraft that are dissimilar in both structure and aerodynamics is also contraindicated. It MAY work fine, but flutter testing is already the scariest thing that one can do in an airplane in Phase I, even in an aircraft design that's been proven with thousands of flying instances. Doing so in a brand new design (which is what you've created here) is not going to lower that fear level at all, since there's now no example of safe flight with it.

Anytime that two cylinders stop working with the LSE ignition, it's almost certainly a failed coil, as Kent says, since the system uses a waste spark configuration that fires two cylinders at the same time from each coil. First, use your EMS to monitor the EGTs when you do the runup on the EI alone and verify that two cylinders (1 & 2 or 3 & 4) are failing to run. If it's only ONE cylinder, then it's not a coil - it's probably a plug or wire. If it IS two cylinders, then swap the coils, and determine if the failed two cylinders follows the coil. If the failure follows the coil, replace the coil. If it doesn't but it is two cylinders failing, then the box is suspect (although there's a small possibility that two plugs and/or two wires have failed).

Listed as sold on Sunday, 12/1/2024.