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MacGyver

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Everything posted by MacGyver

  1. Issues for your consideration: 1. You have no information on the ancestry of the airplane 2. The airplane was advertised as "for parts" 3. You are seeking advice from an informal forum for idea/opinion/information exchange. Here's my take. I would start by acquiring all pertinent data about the VariEze (plans, Canard Pusher newsletters, etc.), and spend a decent amount of time learning about, understanding, and familiarizing yourself with the basic airplane and its evolution over the past 3 decades. Do this before you start bouncing around this (and other "canard" forums) looking for all the answers to your questions. Based on the pictures and info I have seen so far, for this airplane, you have a LOT of work to do, that will likely take much longer than you may think, to get this airplane in a safe, flyable condition. These airplanes (plans-built) must not be considered "plug and play" with respect to restoration and operation. While this airplane may well have been flyable in the past, it certainly is not now, and will take a lot of dedicated and correctly implemented work to bring it back to a Condition for Safe Operation. Seek the counsel of an experienced and knowlegeable VariEze builder who can give hands/eyes-on honest assesment of the project you have taken on. Do not rely on forums such as this to get 100% correct answers or suggestions - there are many opinions expressed on this type of forum that are only that - opinion, and opinions, as convincing/valid as they may seem, can be dangerous if actually implemented on an airplane. From my background (aerospace engineering and 28 years hands-on with VariEzes and Long-EZs), I would not, for example, advocate the installation of any engine on this particular airplane outside what has been documented by the designer (i.e stick with the Continental C-series or O-200, or the Lyc O-235). $$$$$$$$$. Plan on spending more money than you think when working to end up with a safe airplane. This includes spending money with regards to the engine aspects. As relatively inexpensive as alternate engines may seem, and as seemingly well-proven as some may seem, you are still embarked on pretty hard-core experimentation, when installing an alternate engine in something like a VariEze. I've seen this first-hand several times, and in each case, the canard builder ended up falling back on tried & true aircraft engines specified for their particular canard. -Joe Person EAA Tech Counselor 4418 VariEze N79JN Bothell, WA (KPAE)
  2. MacGyver

    Wing Incidence

    Steve, A few questions: 1. What led you to conclude that the wing fittings require re-work or replacement? 2. If planning on installing entirely new wing fittings, what are your plans for "picking up" existing fastener holes in the sparcaps/BID shear pads at the ends of the sparcaps? 3. What will you do to maintain center-on-center bore alignment between the new centersection-side fitting plates and the bores in the wing tongues? I can give you a lot of insight on what the above could entail. FWIW, most-likely, the fittings were made by Ken Brock Mfg., and and as such, the taper pin bores will not be an exact 10 degree included angle. Brock pins/bores (based on my examination of several different sets on an optical comparator) dial in between 9.2 and 9.6 degrees or so. When manufactured, the lathe set-up that made the pins for a given set of fittings was also used to tweak the tapered reamer, thus ensuring as close an "off-the-machine" fit as possible. Pins were lapped to the bores of Brock fittings to ensure a final, accurate pin fit. This, per my discussion at Brock Mfg back in 2000 - I talked to the machinist who made the majority of the wing fittings and looked over the jigs/fixtures on which they were manufactured. Pin fit in the bores is very critical. If you have no prior experience with the VariEze (familiarity with sturcture fabrication, etc.), try to get a qualified VariEze builder (Long-EZ / Cozy builders will know a fair bit, but not all there is to know on a VariEze) to have a look. -Joe Person EAA Tech Counselor 4418 VariEze N79JN Bothell, WA (KPAE)
  3. Mike Drew's wing attach is part of the Jiran pre-fabricated wing system that was used on a very limited number of VariEzes. it is NOT a Long-EZ wing attach scheme, and is essentially as "mechanically intensive" (parts-wise) as the per-plans wing attach. Early in the VariEze program, Rutan looked at the potential for prefabricated wings for the the VEZ. Several sets were built by Jiran, and RAF concluded that the cost and effort had no advantage over the per-plans wing configuration. Go back and study your Canard Pusher newsletters for the story here. The per-plans VEZ wing attach scheme is lighter than the Jiran-wing type system. And yes, I am not posting based on some distant belief or theory (as some seem to) - Mike Drew's hangar is abot 100 feet from mine, and I have looked at his wing attach system in very close detail (wings on and wings off). Mike is not the original builder. FWIW, the TERF CDs were never configured (content-wise) to allow the construction of one of the RAF designs - this is why the full-size templates were not included in the dataset. -Joe Person EAA Tech Counselor 4418 VariEze N79JN Bothell, WA (KPAE)
  4. Make the fittings out of 2024-T3 bare sheet, like the plans indicate. After abrading the surfaces that mate with glass structure like the plans also indicate, clean/etch with Alumiprep (or equivalent), and follow with Alodine (gold colored) or equivalent. Using stainless steel (Corrosion REsistant Steel , or "CRES" as we call it) can pose other corrosion problems, believe it or not. If not properly prepared for bonding, bad corrosion can occur along the bond surface. In addition, you'd have to select a CRES alloy for proper strenght (yield and ultimate), as well as one that is machinable and allows taper pins to be lapped in to fit adequately. Properly manufactured (materials, geometry, pin fit, etc.) and treated with Alodine, along with sealing along all moisture ingression paths (something that takes pictures and more time to describe), the as-designed fittings are fine. -Joe Person EAA Tech Counselor 4418 VariEze N79JN Bothell, WA (KPAE)
  5. Jamie, Yes, that was a passenger - with 7 gallons of fuel, the Eze was at around 1120 pounds. That was a local flight, not cross-country. My Eze back seat is comfortable up to around 200 pounders. Above that, and above 6 feet tall, the back seat starts to get what I consider snug. My placarded max weight for my Eze is 1200 pounds. -1.2/+3.8 Gs at that weight. I built mine, and I know exactly the condition of all primary structure, including sparcap/wing fitting interface, and, I was able to quantify that weight analytically, not just from a random perspective. Matter-of-fact, when I described my deviation from the per-plans steps to building up the sparcap/wing fitting interfaces face-to-face with Burt Rutan 10+ years ago, he remarked that in retrospect my approach was what he should have specified in the plans, to best-ensure optimum structural performance and minimization of potential for error. For one just starting out, I'd not recommend an O-320 in a VariEze. If you like very nice cruise speeds, and good overall performance/economy, a lightweight O-200 (100 hp) Eze is hard to beat. At 16,500, I can get 150 - 155 knots true out of mine (electronic ignition on one bank of plugs), burning 3.3 gph. You need to try both a VariEze and a Long-EZ on for size first. I had the opportunity to do both airplanes (co-built a Long-EZ, and flew both front and back seat in same, and a back seat ride in a VariEze) before I committed to going the VariEze route. I cannot stress how important having a light overall airplane is, if going the VariEze route. -Joe Person VariEze N79JN Bothell, WA (KPAE)
  6. Jhicks, at 230 to 240 pounds, you will have a verrrry snug fit in a stock VariEze (VEZ). My VEZ is one inch wider, primarily to give the rear seater extra shoulder room. The first time I tried on a VEZ back seat, my shoulder bones were "in" the longerons, and not comfortably. I'm 6' and 218 right now - back when I first sat in the back of a VEZ, I was 210 - 215 or so. That was 22 years ago. I've had a 240 pounder in the back of my VEZ, and he was snug, to say the least. The one-inch width increase I designed into my VEZ yielded some bonus width for the front seat. You may wish to make a post regarding your interest to see others' airplanes on the canard-aviators group on Yahoo, and on EZ.org. FWIW, I started "hands-on" with canards when I was 19 (gives me 28 years now, messing with these infernal things...) - I helped a friend build his Long-EZ while I was in college, and after I graduated and ended up at Boeing, my flying needs and budget (I did not wish to borrow any money for an airplane) dictated that the VEZ was my best option. I'm still happy with the decision after all these years. My free advice here (all I ever give in these forums) is to take your time researching, get to look at others' airplanes, get a ride or 2 (this is usually not a problem, overall), and don't make any snap decisions, should you end up in the mode of buying a completed airplane. In fact, I'd suggest that if you settle on a particular design, consider building from scratch. Building it yourself is the best way to get the airplane you want, and the best way to know exactly what is in the airplane, with regard to how well/carefully it is built. There are some fine airplanes that come up for sale, but there also some real dogs, or even downright unsafe ones that also pop up once in a while. Patience, Luke... Joe Person EAA Tech Counselor 4418 VariEze N79JN Bothell, WA (KPAE)
  7. Norm, You have a lot of homework to do. Your VEZ's POH, as finalized by the builder and/or as updated by the last owner if W&B changes occurred, should have had a notation for min/max front seat pilot weights. FWIW, Structurally, the VEZ is limited to 255 pounds in the front seat, due to structural limitations of the nose gear strut. Take time with all this stuff mate. Any plans-built homebuilt must be considered a "one-off" airplane, with respect to W&B, handling, flight characteristics, maintenance requirements, etc., etc., etc. No such thing as "safe plug & play" here, unless the builder, and any prior owners, were fastidious about the building, care, and feeding of the airplane, and maintained commensurate records. Again, start by reading and getting to know the evolution of the VEZ by reading the Canard Pushers. Take the time to do a complete examination of the airplane, based on the 25+ years of service experience and associated changes detailed by Rutan Aircraft Factory. In your CP readings, you will find the CP where Burt gave the 1110 pound max T/O weight, with associated requirements. You will also find the reference to the reason behind his max front seat weight limit. As for 628 pounds empty, that is actually very good, from a global perspective of completed and flown VEZs. FWIW, the only time I go full fuel is when solo. Like any airplane, you should only load to meet mission requirements, with whatever reserves you must have. Take your time, do it right, and don't end up like another gent last year, who had a midlife crisis, bought a VEZ (with at least one documented serious deficiency, and several other "by observation" deficiencies), and wadded it up in a ball in the midwest in May, 2008 during an attempted forced landing (coulda killed him, but he got lucky). -Joe Person EAA Tech Counselor 4418 VariEze N79JN Bothell, WA (KPAE)
  8. Norm, Before you start usung this and other forums, I highly recommend reading all of the Canard Pusher newsletters as a start. If you did not receive any of them when you purchased your VEZ, you can find them here: http://www.cozybuilders.org/Canard_Pusher/ In particular, please read this one: http://www.cozybuilders.org/Canard_Pusher/RAF_inspection.pdf Finally, be cautious on getting advice from those who have never built a VariEze - there is a lot of commonality between the VariEze and her "descendants" (e.g. Long-EZ and Cozy), but a Long-EZ or Cozy builder who has no direct VariEze experience may not know the details about wing attach, MLG attach, etc. that are different on a VariEze. 'Bout all I can say. -Joe Person EAA Tech Counselor 4418 VariEze N79JN Bothell, WA (KPAE)
  9. OK, my bottom-line take. If you bought your airplane, and did not build it, and are completely new to experimental homebuilts, and have no other good hands-on aviation experience, I'd not advocate going out and blindly hanging a far-bigger engine on a VariEze. Bill "Duck" Oertel is an extremely talented and capable builder, mechanic, and pilot. For a newbie to charge out and do such a thing is quite a different matter. Unless you can correspond directly with one who has also done what you wish to do with your particular airplane, can give all necessary data for the change (is willing to share the info), AND who has hundreds of hours of service experience to share, you will be piece-mealing your conversion, and possibly on the advice of several individuals. The bad thing about being a newbie and taking on-line advice from multiple sources is that important/critical integration-level aspects can be missed or simply not realized. I've seen this first-hand on two occasions, one of which was almost fatal. Now I gotta go finish that Hill's Hoist autogyro (gotta start simple, and I don't have an O-320 lying around right now. -Joe Person EAA Tech Counselor 4418 VariEze N79JN Bothell, WA (KPAE)
  10. With sufficient duct tape, yes, and as long as the hoist is not full of Ocker grundies... -Joe
  11. The O-235, stripped of extras (starter, etc.) was approved by Burt (RAF) for the VEZ. RAF sold plans that detailed this installation, and quite a few VEZs have O-235s. IM(experienced)O, the O-320 is too much engine for the VEZ, unless you seek a single-seat crotch rocket that climbs like all hell. Virginia Skiby had an O-320 VEZ years back, and ran it in races. I doubt that airplane could compete these days. The problem with adding a heavier engine to an airplane that was designed for lighter engines lies with the need to reinforce structure, and knowing how to do that. I would not simply bolt an O-320 on my VEZ without knowing what else I had to do with the airframe. Adding a heavier engine will do nothing for your gross weight. Max over-gross for the VEZ (assuming you DON'T follow the latest recommendations from Burt on the VEZ) was 1110 pounds, with a 1050 pound limit for landing, and at least a 90 hp engine. If you did not build the VEZ to begin with, and entertain adding a bigger engine to up the gross weight capability, forget it, and get a Long-EZ. All the bigger engine will do on a VEZ is reduce your gross weight, and increase the risks associated with the operation of an overloaded airplane. The O-200 is quite adequate for the VEZ. I have flown a VEZ with an 85 hp, as well as a 100 hp engine. Both perfomed well. I have a 617 pound (empty) VEZ with a stock O-200, and Electroair EI replacing one mag. I can get off at near gross (1200 pounds for my own airplane) at Jackpot Nevada on a 100 degree F day, and have enough runway margin to be comfortable. FWIW, my 1200 pound gross was not an off-the-cuff conclusion. Being the builder, I knew exactly how well-crafted all the airfarme structures were, I knew that the airframe had no hidden anomalies (e.g. sparcap swelling/distortion in one VEZ that prompted Burt to issue his latest operational limitations recommendation recently), and being an aerospace engineer, I knew how to "run the numbers" for my airplane. As for jet-powered canards, I have seen a Cozy done this way, and I think I've seen a Long-EZ done this way, but never a VariEze. Personally, if going for a higher HP engine for a VEZ, I'd consider the Jabiru 3300, but I'd wait for others to spend the time and $$$$ proofing-out the installation and gathering/accumulating the service experience. The VEZ is best built/kept as light and simple as possible. I always felt sorry for those VEZ drivers who had 750 pound (empty) airplanes. They would never get to feel the acceleration and climb that one experiences in a 600-pounder. -Joe Person VariEze N79JN Bothell, WA (KPAE)
  12. MacGyver

    Varieze

    Norm, Properly set-up, the wing fittings are good to about 16 gs - plenty-strong. In overload, and assuming you do not fail glass structure, the aluminum .125 plates on the centersection spar will fail in a shear tearout mode before anything else does, and the pins will remain OK. Not theory here, BTW, but evaluations of three separate VEZ crack-ups I have assessed directly (including one of my own in 1998). Original pin design is more than adequate, and remember, Burt was extremely concerned about weight, as all good designers (and builders) should be. The per-plans pin design was a refined one, from a strength-to-weight perspective. Burt was not a designer to compromise anything for a "neat" result. In fact, he is quite the opposite. Your idea for solid pins sounds fine. 5-10 foot-pounds is too high, as you have discerned. Press on! -Joe Person EAA Tech Counselor 4418 VariEze N79JN Bothell, WA (KPAE)
  13. MacGyver

    Varieze

    Norm, The pins' fit in the bores can be checked with engineering/Prussian blue. They need to have a very well matched fit. As for filing, I hope you intend to use a lathe. When Ken Brock made the fittings (the original supplier), the pins were matched to the tapered reamer that made the tapered bore in the entire fitting assembly stack-up. This ensured a very good match overall. The problem with poorly-fitting pins lies with an end-result of one of the .125 plates on the centersection spar picking up more of the load that the other. Example: If the inner plate picks up load before the outer plate does, you induce a bending moment in the glass sparcap itself. With the sparcap reacting this moment, worst-case, you can fail the sparcap in bending before you ever get to design max g. As for pin hardness, per plans the pins are supposed to be heat treated to 125 ksi. You do not want to begin any distortion of the pins at lower loads. Stock pins were 4130, heat treated to 125 ksi, with a cadmium plating. By design, included angle was supposed to be 10 degrees. Generally, Brock-manufactured pins dialed in between 9.2 and 9.7 degrees or so (based on measurements I made on an optical comparator on 4 different sets of Brock pins, over sevral years). Properly manufactured (correct materials and such), and with correct geometry/fit, the VEZ wing fitting is very robust and will give a long service life. You should not have to be concerned with "pins wearing out". Again, all things being correct, the pins will not wear out, nor will the bores. Gerry Gardiner, of Sheridan, WY, has a 4500+ hour VariEze built in the 1970s. He trailers his Eze to and from the airport (since day-one, effectively), for every flying session, which entails wing removal/installation far beyond what almost all of the operational VariEze fleet experiences. Torque for the through-bolts is 36 - 40 inch-pounds, no more. If you have to use more torque to snug things up, something is not right. Refer to CP 61 for critical information on VEZ taper pins, and what can happen if the wing/centersection interface is not rendered correctly. I'd plan on going through the airplane with a fine-tooth comb. One of the most important aspect of these types of airplanes is that each is unique. Some are built/integrated better than others. Be cautious, and be careful whom you rely on for help online. Read ALL of the CPs - those of us who built these airplanes (the conscientious ones, anyway) had to read all CP information associated with our airplanes. Familiarize yourself with your airplane's configuration, based on the plans and CPs. Feel free to give me a holler anytime - ezejoe@comcast.net. Meantime, read the excerpt from CP 61 (below), and go have an Emu beer for me... Cheers, -Joe Person EAA Tech Counselor 4418 VariEze N79JN Bothell, WA (KPAE) From CP 61: IMPORTANT All VariEze builders and flyers should be aware of the seriousness of this situation. If you know of anyone flying a VariEze who may not be receiving the Canard Pusher, please pass on the following critical information: 1) A mandatory inspection of the long AN-4, 1/4" diameter bolts and nuts that secure the steel tapered plugs into the wing fittings. There are four (4) of these bolts, each must be removed and carefully examined for any evidence of over-torquing (stretched threads, necked down diameter anywhere on the length of the bolt). Double check to see that the threads on each bolt are not bottoming in the threaded lower taper plugs. You may have to use thin shim washers under the head of each bolt to assure a proper fit with no bottoming of threads. Check that the jam nuts have at least 1-1/2 to 2 threads showing after they are tight. If you purchased your VariEze wing fitting from Ken Brock Manufacturing, you will notice that the AN-4 bolts have a longer CP61, Page 10 -------------------------------------------------------------------- than standard thread (Joe Person Note - these were not AN-4 bolts, they were Grade 8 bolts that were cadmium plated like an AN bolt is). These threads as they are on any AN bolt are not cut threads, they are rolled threads. If you see any evidence of the threads having been cut with a threading die, discard them and install new bolts. Look for any corrosion on these bolts. Any corrosion should be carefully cleaned off and the bolts should be greased before re-installing them. Excessive corrosion is cause to discard the bolts. If you did not personally install the bolts, you may have to assume that they might have been over-torqued. Any suspicion of over-torquing is cause to discard these bolts. If your wing attach fittings were not manufactured by Ken Brock Mfg., you will need to carefully inspect the tapered plugs for perfect fit in the tapered holes. If in doubt, you may have to carefully lap each plug into its tapered hole, checking for perfect fit with engineering blue. Check to be certain that the tapered plugs do not go too deeply into the tapered holes. The top of the plugs must not go below flush with the top of the wing fittings. The design of a wing fitting such as the VariEze calls for the tapered steel plugs to take all flight loads. The AN-4 bolts should never see flight loads. All they are for is to retain the tapered plugs. If the tapered plus are a perfect fit, these bolts will require only a very light torque to snug the plugs into their respective holes. Three (3) foot/lbs. (36 inch/lbs.) of torque are all that should be required. If you need more torque to pull the tapered plugs into their tapered holes, your tapered plugs do not fit correctly. Do not fly until you have corrected this situation. Two people have died because of improperly fitting wing attach taper plugs. Do not take this lightly. Your life depends on these wing attach fittings. You owe it to yourself and your passengers to do absolutely the very best work you are capable of here. This is especially true if your wing fittings are homemade. The Brock fittings are very accurately machined and all the tapered plugs are hand lapped and fit perfectly. Once you have installed a pair of tapered plugs and torqued the bolt (3 ft./lbs), as a double check, remove the bolt and check for a tight fit of each taper plug. It should take a sharp blow with a wood drift to loosen each plug. If the plugs fall out or are not tight, they do not fit correctly. Fix this problem before next flight.
  14. MacGyver

    Varieze

    Norm, The pins' fit in the bores can be checked with engineering/Prussian blue. They need to have a very well matched fit. As for filing, I hope you intend to use a lathe. When Ken Brock made the fittings (the original supplier), the pins were matched to the tapered reamer that made the tapered bore in the entire fitting assembly stack-up. This ensured a very good match overall. The problem with poorly-fitting pins lies with an end-result of one of the .125 plates on the centersection spar picking up more of the load that the other. Example: If the inner plate picks up load before the outer plate does, you induce a bending moment in the glass sparcap itself. With the sparcap reacting this moment, worst-case, you can fail the sparcap in bending before you ever get to design max g. As for pin hardness, per plans the pins are supposed to be heat treated to 125 ksi. You do not want to begin any distortion of the pins at lower loads. Stock pins were 4130, heat treated to 125 ksi, with a cadmium plating. By design, included angle was supposed to be 10 degrees. Generally, Brock-manufactured pins dialed in between 9.2 and 9.7 degrees or so (based on measurements I made on an optical comparator on 4 different sets of Brock pins, over sevral years). Properly manufactured (correct materials and such), and with correct geometry/fit, the VEZ wing fitting is very robust and will give a long service life. You should not have to be concerned with "pins wearing out". Again, all things being correct, the pins will not wear out, nor will the bores. Gerry Gardiner, of Sheridan, WY, has a 4500+ hour VariEze built in the 1970s. He trailers his Eze to and from the airport (since day-one, effectively), for every flying session, which entails wing removal/installation far beyond what almost all of the operational VariEze fleet experiences. Torque for the through-bolts is 36 - 40 inch-pounds, no more. If you have to use more torque to snug things up, something is not right. Refer to CP 61 (repeated below) for information on VEZ taper pins, and what can happen if the wing/centersection interface is not rendered correctly. I'd plan on going through the airplane with a fine-tooth comb. One of the most important aspect of these types of airplanes is that each is unique. Some are built/integrated better than others. Be cautious, and be careful whom you rely on for help online. Feel free to give me a holler anytime - ezejoe@comcast.net. Meantime, read the excerpt from CP 61 (below), and go have an Emu beer for me... Cheers, -Joe Person EAA Tech Counselor 4418 VariEze N79JN Bothell, WA (KPAE) CP 61 - Taper Pins A VariEze crashed in Southern California recently and both occupants were killed. There was one eye witness who reported observing the VariEze performing some aerobatic maneuvers before it abruptly lost power and fell to the surface of a wet salt pan. The VariEze hit the surface essentially flat with little or no forward motion and was inverted. These very unusual circumstances called for a full investigation. Two representatives from RAF assisted the FAA in trying to determine what might have caused this tragedy. The investigation team was forced to use a helicopter to examine the crash site since it was not possible to walk across the muddy salt pan which was many feet deep in places. It was obvious from 300 feet above the crash site that the VariEze had impacted inverted, with little or no forward or lateral velocity. This was evidenced by the mud splash marks radiating out from the center of impact. CP61, Page 9 -------------------------------------------------------------------- The RAF representatives returned to the crash site several times over the next three days and many photographs were taken, and there was much discussion and theorizing. While the exact cause may never be known for absolute certain, it is our belief, based on our knowledge of the VariEze design as well as our previous experiences examining several crash sites somewhat similar to this one, that this aircraft fell essentially vertically onto the surface of the salt pan. It struck the salt crust in a nose low, wings level, but inverted attitude. There was no evidence of a spin, no sign of rotation at the time of impact. The engine was not developing power and, most probably, was not even windmilling. Two of the the eight large wing attach taper plugs were missing. We believe they departed the airplane in flight, as did the AN-4 bolt and nut that secures them in place. When the remaining six taper plugs were removed, they were easily removed without having to drive them out. All three AN-4 bolts had had the length of threads increased to about 3/4" using a threading die to cut these additional threads. All three bolts showed evidence of elongation of the threaded area where they had stretched possibly due to being over-torqued. We theorize that possibly the fourth bolt was over-torqued to the point of failure, or almost failure. During this last flight, and probably aggravated by the acrobatic maneuvers, this bolt failed. None of the taper plugs fitted very well into the tapered holes in the wing fittings. For this reason, we believe that the two forward plugs on the left wing worked their way out of the tapered holes after the bolt broke, thus allowing the left wing to pivot aft on the aft two tapered plugs. There are marks on the left wing attach fittings which clearly show that the wing pivoted aft as much as 15 degrees. The wing swinging aft by itself would not have caused this accident, however the winglet mounted on the end of the wing swinging 15 degrees left would create a powerful yaw with perhaps four times the authority of the rudder alone. Such a huge yaw angle would immediately drive the aircraft into a drastic departure from controlled flight. The airplane would flip over and experience heavy negative "G" forces which would cause the engine to starve of fuel, whereupon it would quit. Apparently, this tumbling departure occurred at a rather high speed because the enormous negative, as well as positive "G" forces overstressed the aluminum wing fittings as evidenced by the considerable elongation of the taper plug holes in the outer plate, both top and bottom, of each wing. The inner plates of each wing fitting, top and bottom, showed much less evidence of elongation, leading us to conclude that the home made taper plugs did not perfectly fit into the tapered holes. It is probable that the left wing, swept aft, may have caused the airplane to fall in a somewhat stable inverted spiral (as described by the eye witness). Flight experience and NASA testing have shown that a normal VariEze cannot maintain an inverted developed spin. There is no evidence to suggest that there was any inflight structural failure of any composite parts. Every single part of this aircraft (with the exception of the two wing attach taper plugs and the securing bolt) were found at the impact site. -------------------------------------------- IMPORTANT All VariEze builders and flyers should be aware of the seriousness of this situation. If you know of anyone flying a VariEze who may not be receiving the Canard Pusher, please pass on the following critical information: 1) A mandatory inspection of the long AN-4, 1/4" diameter bolts and nuts that secure the steel tapered plugs into the wing fittings. There are four (4) of these bolts, each must be removed and carefully examined for any evidence of over-torquing (stretched threads, necked down diameter anywhere on the length of the bolt). Double check to see that the threads on each bolt are not bottoming in the threaded lower taper plugs. You may have to use thin shim washers under the head of each bolt to assure a proper fit with no bottoming of threads. Check that the jam nuts have at least 1-1/2 to 2 threads showing after they are tight. If you purchased your VariEze wing fitting from Ken Brock Manufacturing, you will notice that the AN-4 bolts have a longer CP61, Page 10 -------------------------------------------------------------------- than standard thread (Joe Person Note - these were not AN-4 bolts, they were a Grade 8 bolt that were cadmium plated like an AN bolt is). These threads as they are on any AN bolt are not cut threads, they are rolled threads. If you see any evidence of the threads having been cut with a threading die, discard them and install new bolts. Look for any corrosion on these bolts. Any corrosion should be carefully cleaned off and the bolts should be greased before re-installing them. Excessive corrosion is cause to discard the bolts. If you did not personally install the bolts, you may have to assume that they might have been over-torqued. Any suspicion of over-torquing is cause to discard these bolts. If your wing attach fittings were not manufactured by Ken Brock Mfg., you will need to carefully inspect the tapered plugs for perfect fit in the tapered holes. If in doubt, you may have to carefully lap each plug into its tapered hole, checking for perfect fit with engineering blue. Check to be certain that the tapered plugs do not go too deeply into the tapered holes. The top of the plugs must not go below flush with the top of the wing fittings. The design of a wing fitting such as the VariEze calls for the tapered steel plugs to take all flight loads. The AN-4 bolts should never see flight loads. All they are for is to retain the tapered plugs. If the tapered plus are a perfect fit, these bolts will require only a very light torque to snug the plugs into their respective holes. Three (3) foot/lbs. (36 inch/lbs.) of torque are all that should be required. If you need more torque to pull the tapered plugs into their tapered holes, your tapered plugs do not fit correctly. Do not fly until you have corrected this situation. Two people have died because of improperly fitting wing attach taper plugs. Do not take this lightly. Your life depends on these wing attach fittings. You owe it to yourself and your passengers to do absolutely the very best work you are capable of here. This is especially true if your wing fittings are homemade. The Brock fittings are very accurately machined and all the tapered plugs are hand lapped and fit perfectly. Once you have installed a pair of tapered plugs and torqued the bolt (3 ft./lbs), as a double check, remove the bolt and check for a tight fit of each taper plug. It should take a sharp blow with a wood drift to loosen each plug. If the plugs fall out or are not tight, they do not fit correctly. Fix this problem before next flight.
  15. MacGyver

    Varieze

    Observations: 1. Sounds like you have a gascolator that uses a pull cable, similar to that on a Cessna 150 (?) 2. SCEET/CEET should NEVER be used for induction hose - the inner layer can separate from the rest of the tubing, and cause an engine shutdown. 3. Make sure your taper pins for the wing attach are lapped into the bores of the fittings (with the wings installed and jigged so as not to move). Lack of uniform contact in the bores here can result in sparcap overloads at lower g loads that one would expect (e.g. as low as 2.8 gs). Pins are 4130, heat treated to 125 ksi, FWIW, per plans. 4. A Silver Bullet on a VEZ with an O-200 will not yield any "magic" results unless you have a good O-200 (i.e. capable of developing rated HP) and a clean airplane (drag-wise). I fly a Silver Bullet on my O-200 Eze (speaking from experience here). 5. A static RPM of 2300 is not bad at all - you should, as noted (with all other parameters running "100%") be able to get 2750 wide-open, down low.
  16. Yes, My VEZ is one inch wider, from the firewall, to the forward-most bulkhead on the forward end of the NG30 structures. I'm tied up for the next two weeks, but shoot me an email at ezejoe@comcast.net in about 2 weeks and I'll give you the full details. And yes, my Eze is flying, so this one-inch width increase is not "theoretical". -Joe Person VariEze N79JN Bothell, WA (KPAE)
  17. MacGyver

    new here

    Those specs are for the very original VariEze Burt built (N7EZ) - that airplane is in the EAA Museum in Oshkosh. That version was never offered via plans. The VariEze plans allow you to build a copy of N4EZ (currently on display at the Udvar-Hazy wing of the Air and Space Museum at Dulles), which is the "plans built" prototype. The plans-built VariEze generally utilizes a Continental O-200 engine, with C-85, C-90, and O-235 engines also suitable for use. Ideally, a VariEze should not weight too much beyond 600 - 625 pounds. There are some that are 750+, which is too heavy to be considered a two-place airplane. A "general" VariEze spec might look like this: 640 empty O-200 (100HP) Day VFR instruments Cruise 150 Kts Top Speed 175 Kts Landing Speed 65 Kts Range 700 NM Minimum Runway (Sea Level, Standard Day) 2500' -Joe Person EAA Tech Counselor 4418 VariEze N79JN Bothell, WA (KPAE)
  18. Happy to pop down in the Eze (I always look for good excuses to fly). Give me a ride from Thun or Tacoma Narrows (whichever is closer) to see your laboratory, and I'm happy to pop down. Feel free to contact me on the side as well - ezejoe@comcast.net -Joe
  19. Had an EAA Tech Counselor visit on your project? If not, when the WX is good, happy to pop down and have a look. -Joe Person EAA Tech Counselor #4418 VariEze N79JN Bothell, WA (KPAE)
  20. Carbon fiber - nice for some apps, but no real benefit strength-to-weight if using our hand lay-up techniques (i.e. no better than S-glass, for example). If using it (and I have made Long-EZ ailerons with carbon, as that is what the builder of the airplane wanted), the wetting-out takes patience and close examination (easy to get too wet), and, the need for a glass barrier ply between any aluminum and carbon is absolutely required. You also have to remember to not use the aluminum "pop" type rivets as specified in the plans either, as they mingle with the carbon. Monel pull-type rivets offer the best material compatibility. Then, you have a harder rivet through relatively softer materials, and you have to be careful if drilling them out (like when you have to replace a hinge). Me? I'd stick with the per-plans construction, do your best workmanship, and sand them as Rutan recommends. Then, once painted, re-check for balance. My ailerons required additional balance weight (about 4 ounces per aileron). I've built 4 VariEze ailerons, and yes, I do build light (VariEze #2 is 617 pounds empty, with goodies & tools, etc.). To balance my ailerons, I simply drilled a 1/4 inch hole in each end of the aileron, immediately aft of the steel rod, and used 1/4 inch diameter lead (you can buy 1-pound spools of this at fishing stores) potted in with epoxy. Simple. I have flutter-tested my airplane to 225 knots or so, with control system jabs/sweeps, with no problems. The ailerons are much more tolerant of weight increase than the elevators, FWIW. -Joe Person VariEze N79JN Bothell, WA (KPAE)
  21. She'll be 21 in March (and legal to drink everywhere...), and is still in operation, plying her trade with a US operator. From 20 years back in my memory banks, restoration required engine work (I do not know if the CFM-56's required replacement), structural repairs on the belly, overall structural inspection of the structures/zones that such an event would require, etc. As for Airbi, ah mon frere, they are headquartered in Toulouse, in a similar manner that Boeing Commercial Airplanes (division) is headquartered in Renton, Washington, but The Boeing Company as a whole is headquartered in Chicago. "Ah'm French! Why do you think Ah have this outrrrrageous accent, you silly king!?" -French Taunters, "Monty Python and the Holy Grail"
  22. Refuse Toulouse! Pure humo(u)r (extra vowel , just in case...) disguised as wanton jingoism! Airbus is headquarted in Toulouse, and no worries - I had some fine interactions with some of my counterparts from that consortium across the pond. Matter of fact, on one occasion, we had burgers...
  23. Ghost, The hinge arms for the Roncz canard are dimensionally different from those for the GU canard, and could not be used in place of the hinge arms for the GU canard. GU hinge arms are GU hinge arms - it does not matter whether they were originally procured for a VariEze or a Long-EZ, as both airplanes used the GU canard, until the Roncz canard was developed for the Long-EZ in the mid-80s. Keep checking around, and I do suspect you will be able to find a set, unused, as I previously noted. Check/ask on the ez.org site, as well as the canard aviators group on Yahoo. -Joe
  24. Ghost, Post some pictures - some corrosion may be acceptable, depending on amount/depth/severity/type. If replacing the hinge arms, yes, the currently-available inserts (made by the Cozy Girrls) are for the Roncz canard, and are not the same parts as were used on the original "GU" canard. Overall, it may be prudent to simply replace the hinge arms, especially if there is any chance that corrosion has propagated into the areas beneath the flox potting in the canard. Unless I was sure that whatever corrosion I had was limited totally to the exposed sections, AND could be blended out without detirmental effect to the strength, I'd replace the hinge arms. If removing the existing hinge arms, a Rotozip-type bit used in a Dremel tool, carefully used around the periphery where the hinge arm is floxed into the canard, is a good way to remove the flox. I've done this as part of the installation of a new set of elevators on another gent's purchased VariEze - the hinge axis of the original elevators (along with their being incorrectly shaped, too heavy, and out of balance) was all over the place. With the new elevators constructed and the hinge axis correct, the hinge arms in the canard required replacement. Using a Rotozip bit and carefully working around the hinge arms, removing a little depth of flox per pass, was the way to go. You may check around on the various forums in your quest for a set of hinge arms - refer to the plans for the correct part number. With the advent of the Roncz canard for the Long-EZ back in the mid-80s, there are bound to be some builders who have the hinge arms for the GU canard, that are unused. As part of the pre-installation of such metal parts into a composite airframe, after the "bonding" areas of such parts are scuffed with 220 grit sandpaper (as detailed in the plans), treatment with Alodine 1200 or 1201 (the "gold" tinting Alodine, or equivalent), is prescribed. Hope this helps. -Joe Person EAA Tech Counselor 4418 VariEze N79JN Bothell, WA (KPAE)
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