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of Canard Composite Aircraft
By Terry Yake
“Aviation in itself is not inherently dangerous. But to an even greater degree
than the sea, it is terribly unforgiving of any carelessness, incapacity, or
neglect.” – unknown. “This statement applies to homebuilt aircraft to even a
greater degree.” – Central States Association.
2.0 Family Tree
3.1.1 Resin types and properties / Fillers
3.1.2 Delaminations and Repair
3.1.3 Re-painting- CAUTION
3.2 Control surfaces
3.2.1 Trailing edge fences
3.2.2 Vortex Generators
3.2.3 CP 103 Aileron rod end AD for the Long-EZ
3.3 Fuel tanks
3.3.4 Debris screens
4.1 Wheel calipers
5.0 Engine Systems
5.1 Spark Plugs
5.2 Oil FIlters and Oil Cooling systems
6.2 Types – Fixed pitch and Constant speed
6.3 Material – metal or wood composite
6.4 Wood Prop care
7.0 Electrical Systems
8.0 Wheels/Tires/Brakes/Landing Gear
8.1 Brake lines and Fluid
8.2 Long-EZ nose wheel axle bushing rotation
8.3 Long-EZ main gear attachments/hard points
10.0 Miscellaneous Helpful Information
Rule #1: Just because it's an EXPERIMENTAL, doesn't mean the laws of physics don't apply. (The view from the green side of the dirt is best)
This guide is intended for the owners and fliers of composite canard aircraft that did not build the plane. If you already have made the purchase, one major step has been completed. In addition, you have probably encountered maintenance issues, parts source questions, and procedural problems that would be known if you had built the plane. Even the supportive A&P and/or AI has little if any familiarity with some aspects of the plane you want him to maintain. Unless you have a continuing relationship with the builder, some of the rules for safe handling, fabrication techniques for repairs, and parts identification and sources may be a problem for you.
With the increasing number of composite canards being built and later sold, the educational aspect of the prolonged construction process and completing a flyable aircraft are lost to the next owner. Even if you received all the builder’s documentation, which hopefully you did, much of it is hard to put in order. During the building period, many years elapse typically. During that time, there was an opportunity to read, re-read, and re-read again the construction manuals and product brochures, POH (Pilot Operating Handbook), see and talk to others at Oshkosh, EAA chapter meetings, and “hangar talks” by those ahead in the building and flying phases. As you attend fly-ins with your “new acquisition”, you are possibly able to quote the features of the plane to by-standers, but the intimate knowledge of how and why something was included or excluded in your plane just isn’t known.
So, with your continued enjoyment and safety of operation in mind, this guide is intended to highlight many general aspects of the unique aircraft you own, are responsible for, and fly. It is intended to serve as a supplement to the construction plans, owner’s operation manual, and other documentation that you should be intimately familiar with already. It can’t replace the knowledge you would have acquired by building it yourself, but offers an opportunity for some tribal knowledge transfer, gleaned from some very knowledgeable builders and fliers who are in addition professional subject matter experts in their own right.
In this booklet, you will find a topic listing, presentations, and references to sources for parts. It is not intended to be a substitute for the designer’s composition, the manufacturer’s construction plans, instructional materials or any official operational documentation. You must also know these materials to properly fly and maintain your aircraft. And just because we didn’t think to include every imaginable technique or procedure, doesn’t mean it wasn’t important enough to mention.
you are not already a member of the Experimental Aircraft Association, join now.
Find the local EAA chapters in your area where members have planes
similar to yours, and join this association.
Subscribe to the Central States Association Newsletter for Rutan and
derivative canard designs. Your
aircraft designer/manufacturer has a newsletter. Subscribe to it.
Subscribe to Kit Planes magazine. Attend fly-ins and seek out
other canard fliers. Find canard
aviation chat boards on the internet.
All this leads to being a member of an elite group of similarly minded
people. Enjoy the total experience
of being an experimental aircraft owner.
From the EAA Aviation Information Services (EAA e-Hot Line Q&A, Vol 2, No. 26 10/24/2002):
Question: As a non-builder of a Homebuilt, can I maintain my owned experimental aircraft (except condition inspection) without being supervised by an A&P? If so can you direct me to the specific regulations?
Answer: Yes, an owner can do all maintenance, repair, and/or modification to his experimental/amateur-built aircraft (except the condition inspection) without involving an A&P mechanic. The regulatory reference is 14 CFR 43.1(b), which states:
"(b) This part does not apply to any aircraft for which an experimental airworthiness certificate has been issued, unless a different kind of airworthiness certificate had previously been issued for that aircraft."
14 CFR Part 43 is titled "Maintenance, Preventive Maintenance, Rebuilding, and Alteration", and Part 43.1 is titled "Applicability." Because your experimental/ amateur-built aircraft was originally certificated as such, and was not previously issued any other type of certificate, 42.1(b) tells you that Part 43 does not apply to your aircraft. Thus, the requirement for having an FAA certificated mechanic do the maintenance does not apply.
The condition inspection is a different story. An experimental/amateur-built aircraft is issued a set of operating limitations as a part of it's airworthiness certificate. It is in these "OpLims" that the requirement for a condition inspection is found. The OpLims also specify who can do the condition inspection in the following or a similarly worded statement:
"(26) An experimental aircraft builder certificated as a Repairman for this aircraft under § 65.104, or an appropriately rated FAA certificated mechanic, may perform the condition inspection required by these operating limitations."
If you do not hold the repairman certificate for the specific aircraft you own, then this statement specifies that you must have an A&P mechanic perform the condition inspection.
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Ever try to find your ancestors and you get the lineage confused, because every generation had a George or Mabel in it. Well, here’s a short version of the canard genealogy to keep things straight.
· The Wright Brothers designed and built the first composite canard. But that was a long time ago, and not to digress ---
· One of the early Rutan designs was the Vari-Viggen, but it didn’t find fancy with many builders. You will see a few flying.
· Then, Burt Rutan designed a bunch of composite planes. Some of his “children” or their follow-on interpretations didn’t generate sustained interest or prosper like some may have hoped, e.g. the Quickie, Q200, Dragon Fly, Solitare.
· Burt hit a magic chord with the VariEze (note the correct spelling). This is a plans-built moldless construction type aircraft folks, not a kit. After the Government provided wind-tunnel test data, the Long-EZ (note the correct spelling) was designed.
· Nat Puffer crossed the Long-EZ wing with a 3-place fuselage design and called it a Cozy. Later he sold his hybrid to another outfit and it was renamed the Cosy Classic. Then, Nat designed the Cozy-IV. (See, just like in real life, some kids leave home and change their names. Other’s are kicked out or are lost in a poker game.)
· Burt also designed the push-pull twin engine Defiant, but it cost about twice as much as a Long-EZ and took twice as long to build. (That equates to not many of them being built.)
· Dave Ronnenberg had built many Long-EZ’s, and wanted a higher performance version. He used the Long-EZ wing design, customized a somewhat larger fuselage, updated the construction materials design ( read this as carbon fiber and an O-540) to bring the Berkut (note the spelling) to life. It is a molded composite structure plans-built plane, not a kit-built plane like the Long-EZ and VariEze.
· More recently, the Velocity – another kit built plane -- was designed and developed to offer 4-place seating and a variety of engine and gear combinations as a kit.
Well, that’s about it. If you want to show your savvy, use
the spellings above, and pronounce the “E” and “Z” in Long-EZ. After all, it’s
not a Long-ezz. Furthermore, the VariEze is also pronounced Vari-E-Z. Is
everyone clear on this? The other canard names are pretty straightforward in
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3.1 Wings and Fuselage
Safety Issue: Styrofoam (light blue) will be eaten away by exposure to fuel or fuel vapors. If repairs are needed, research the manufacturer's specifications to find the proper foam type, fiberglass type, ply orientation and resin appropriate to use. Don't guess!!
On all plans-built composite canards, the structures are solid core, typically using Styrofoam, urethane, or Poly-vinyl foam blocks as prescribed. Fiberglass, tri-directional, bi-directional, and uni-directional weaves, are called out in a lay-up schedules by the designer to meet structural load and dent protection requirements.
Many of the planes for sale probably used resins and weave fillers that have been replaced because a more satisfactory alternative was found or because the original material was no longer produced. Compatible substitutes are probably available, but you typically won’t know how to proceed without expert consultation with the designer.
Remember: Two like opinions by unknowledgeable people still yield a bad direction if followed. Dig for factual data and knowledgeable judgments.
This is an important aircraft integrity issue! So, here is a short tutorial on resins and fiberglass.
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Gary Hunter’s input
3.1.1 Resin types and characteristics
220.127.116.11. Working with resins and the weather: If you are working outside with no roof, I can understand your frustration. One must avoid having a lay-up rained on. However, if you are under-roof, or better yet inside a garage or a building with closed sides you needn't be so picky.
If you are working in a building with the doors open for ventilation, the relative humidity in the building will certainly come close to what it is outside. Although, high humidity conditions are not the best for working with epoxies, some resin systems will tolerate it fine. Some resin systems
are susceptible to "blushing" and you will notice a milky appearance to the resin as you work with it. Most of the time, as the resin cures, this milky appearance goes away leaving an oily like film on the surface of the cured laminate. It looks and feels terrible, but not to worry, this film will
wipe off with warm water and wash cloth.
The biggest concern I have, is problems relating to the applicator and how he or she responds to high humidity conditions. If you are a sweat hog like myself, dripping beads of sweat into your work can be a real big problem. A few drops of sweat on a laminate that has already been completed but not fully cured is not so bad - just don't rub or squeegee it into the laminate - simply blot it and let it dry. Sweating on the dry fiberglass, or a layer of the laminate that is in the process of being wetted out is a big NO-NO.
This is one reason I advocate you find a way to "temper" the air in your shop. Your project will go a lot faster, and you will enjoy it more – both in the winter and the summer.
EAA Technical Counselor
18.104.22.168 Resins/Characteristics –
1) Difference between EZ-Poxy and EZ-Poxy II (should I switch to II mid-project? And are they compatible in cured form?)
Actually, what you are referring to was called SAFE-T-POXY and SAFET-T-POXY II. The SAFE-T-POXY II uses exactly the same resin, but the hardener was reformulated just a tad to give a lower viscosity to help wet out. Today they are called EZ-POXY 10 Resin and EZ-POXY 83 (the regular Safe-T-Poxy hardener) and EZ-POXY 84 (the Safe-T-Poxy II hardener). You can switch from EZ-Poxy 83 to EZ-Poxy 84 but do not blend them together. They are 100% compatible in the cured form.
The non-MDA version was never called a Safe-T-Poxy or EZ-Poxy. It was called EPOLITE 2427 A&B from Hexcel. It received mixed reviews and very little was ever sold. I doubt you will be able find it anymore.
2) Can these parts warp? Does post-cure stop this? If so, temps and times recommended please. Do they REALLY take a year to cure or am I being fed
some false information...
Yes, parts can warp. Yes, a post-cure can HELP to stop this. You are receiving mis-information.
Curing of epoxies is a chemical reaction. All chemical reactions are thermally dependant. With the epoxies we use to build our airplanes, ambient temperature cure conditions provide sufficient heat energy to allow the reaction to start. As the reaction progresses it requires more and more energy to perpetuate the reaction. At some point, the available energy from ambient temperature conditions is insufficient, and the reaction stops. For most resins systems, the reaction stops at a point that gives the cured resin a Tg (glass transition temperature )of about 125-135F. Most of this occurs in the first 24 hours of cure and continues very slowly thereafter until it finally plateaus in about 2 weeks.
The chemical reaction can be re-activated by increasing the temperature conditions. This can happen today, tomorrow or a year from now. It can happen deliberately, by placing the object in an oven and baking it (called a post cure.), OR - it can happen on it's own, when the airplane is parked on the ramp during a hot summer day. It can happen in the garage during storage too. All that is required is more heat energy than what was available when the part was initially cured.
If a cured wing panel is quickly exposed to elevated temperatures in excess of it's current Tg, the cured resin can weaken and become rubbery. If the wing panel is not properly supported while it is in this weakened rubbery state, it can sag under it's own weight. As the wing panel absorbs the heat energy and the chemical reaction is re-activated, the resin will cure and additional amount resulting in a higher Tg. Any warping or sagging the wing may have encountered during this elevated temperature state will become permanently set into the wing panel. By storing the wing panels leading edge down, one can minimize if not completely eliminate the possibility of inadvertent warpage during storage.
In many cases, wing warpage can be reversed by quickly exposing the wing panel to an even higher temperature and weighting or forcing the wing back into the proper shape. Similarly, one can induce a deliberate warpage or twist into a wing panel to correct a rigging or trim problem.
In actuality, an epoxy resin / curing agent reaction is never complete until it has been cured at or slightly above it's known maximum glass transition temperature for a minimum of 2 hours. Some of the approved resins are capable developing a Tg as high as 210F. Because of the foam cores and other considerations it is not possible to cure our airplanes at temperatures at or above the maximum Tg of the resin system.
I recommend a post cure schedule that SLOWLY increases the temperature up to 140 -150F over a span of 2 hrs. and a dwell or hold time of at least 4 hrs, and perhaps as long as 12 hrs. (the longer the better) A very gradual cool down is important too. This will drive the Tg of most of resin systems up to about 180-190F.
Gary Hunter 8/19/2002
Technical Service Representative
EPOXY RESINS TECHNICAL INQUIRY
RESOLUTION PERFORMANCE PRODUCTS
Fillers -- Just a bit of materials correctness here. As a builder, it is important to know your materials (and maybe this is more than you wanted to know).
Microballoons are not silica. They contain silica as a component. Silica is silicon dioxide with no other components. Silica glass (or fused silica) is extremely difficult to make requiring graphite or tungsten or molybdenum furnaces operating in an inert atmosphere at over 2000 degrees C. Fused silica is unique in that its expansion coefficient is almost zero (5x10^-7/deg C). Fused silica is commonly used as the containment envelope for the plasmas in mercury vapor and halogen lamps. Microballoons are a silicate based glass known as C-glass.
Type of glass SiO2 Al2O3 CaO MgO B2O3 Na2O+K2O ZnO
C-glass (%) 65~72 1~7 4~11 0~5 0~8 9~13 0~6
E-glass (%) 52~56 12~16 16~25 0~6 5~13 0~0.8 )
One of the carnardians mentioned that fumed silica (which IS silicon dioxide) causes lung damage due to silicosis, which is similar to asbestosis and not curable. One should wear a mask whenever dealing with any airborne particulates (e.g. microballoons, fumed silica, sanding dust, etc.) to keep them little buggers outa yo lungs, but fumed silica will not cause silicosis. Silicosis requires the presence of the crystalline form of silica such as quartz, crystobalite, etc. Colloidal silica (fumed silica) is considered as a nuisance dust by OSHA. For the MSDS go to: http://www.westsystem.com/webpages/userinfo/safety/MSDS406.pdf
For a guide to fillers and the effects of fumed silica additions, (just takes a pinch to reduce the sag tendency - about 1 part colloidal silica to 10 parts of microballoons) go to this web site that I found: http://www.duroplastic.com/FILLOVERVIEW.htm An excerpt follows:
Typical addition levels of filler to Duroplastic resin systems, are given in the following table. In each case, the filler is given in a ratio to resin in mass Resin is taken as 100 parts.
Filler Mix Casting
(for filling & fairing) (Thin resin)
Capolite 15 - 20
25 - 30 5 - 15
Glass Bubbles 15 - 20
25 - 30 3 - 8
Calcium Carbonate , Wollastonite NA NA
50 - 250
Colloidal Sillica* 3
2 - 5 DO NOT USE
* Generally used in combination with other fillers
Marc Borom 8/02
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3.1.2 Delaminating and Repair
Your owner’s construction manual is the best reference for this topic. Especially for the moldless construction technique used on the VariEze, Long-EZ, and Cozy type aircraft, you should test the structure for any signs of delaminating periodically, at the condition inspection minimally. In some cases you may see a slight “bubble” or bulge in the skin when the light and viewing angle are just right. At other times, the “quarter test” should be used to detect a variance in the sound of the quarter tapping on the fiberglass skin. If it sounds hollow, then a delimitation has occurred. Some delams may be repaired by drilling a tiny hole and injecting resin (of the same type used in construction) with a syringe. A weighted or clamped piece of wood over the affected area should restore the structural integrity if it was not too large. If the delaminating is larger than the size of a dollar bill, then fiberglass removal and re-construction is advised.
In some of the early VariEze’s, Urethane foam was used extensively in the fuselage. It does not have the improved bonding qualities of Styrofoam or Poly-vinyl foam as prescribed later, and should therefore, be checked more often for fiberglass-foam delaminating.
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3.1.3 Re-painting --CAUTION--
When you bought your composite canard, maybe it wasn’t in very good cosmetic shape. So, you decide to re-paint it or have someone do it for you. Be very very careful!!!
The fiberglass covering your plane is part of its structural integrity. If you, or the paint shop, sand or sandblast into the fiberglass it can render the part unsafe and no longer airworthy. As has been presented elsewhere in this guide, the paint system needs to provide a UV barrier as well as just enough paint to provide a uniform coloring. White is the prescribed color by all the composite designers. And that is to minimize the heat absorption and surface temperature of the aircraft surfaces and prevent the resin from losing its properties.
No chemical paint strippers are permitted! Keep the MEK at your mother-in-law’s house. These chemical compounds will penetrate the micro-holes in the resin and eat away the underlying foam, making the structure no longer airworthy.
Structural Integrity Warning! When removing paint from the surface of a composite structure, never remove any part of the fiberglass skin. Never use chemical solvents to remove the paint. (Some type of the foarm core portion of the structure can be destroyed!)
See also paragraph 3.2 concerning the weight and balance of control surfaces.
See also paragraph 3.1 concerning the general issues of foam, fiberglass, and resins.
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The Plexiglas canopies are made in a chamber that heats and applies a vacuum to form the shapes required. They have come from various small company sources over the years. A very few are made by the aircraft builder. Yours may clear or tinted, and vary in thickness from someone else’s. In the1980’s a popular manufacturer was Dayton Airplane Factory in New Carlisle, OH. They are no longer in business. There were subsequent manufacturers in that area north of Dayton, OH, but they too are no longer advertising. The only canopy company listed in recent advertisements is Airplane Plastics, in Tipp City, OH, nearby to Dayton and New Carlisle.
See the classified ads in Kitplanes and Sport Aviation. Also, try Todd’s Canopies, Todd Silver www.kgarden.com/todd (954-579-0874)
22.214.171.124 Plexiglas Canopy Repair
One additional word of caution. Polymethlymethacrylate (PMMA) or Plexiglas is extremely sensitive to stress corrosion cracking. Whenever you drill into Plexiglas (either for attaching or crack-stopping) you should observe two rules taught to me by a research scientist whose specialty was Plexiglas:
1) Avoid corrodants - clean the drill with a good detergent and then rinse well with rubbing alcohol and allow to dry. The reason for doing this is that small amounts of oil can stress corrode the drill hole and radial cracks will form and propagate into the bulk plastic.
2) Minimize heating - drill very slowly with a sharp drill. The reason for this is that Plexiglas responds like glass to thermally induced stress. Drilling too fast will heat and soften the plastic at the drill hole wall. If the temperature of the inside diameter of the hole gets above the glass transition temperature of the plastic, the surface of the drilled hole will go into hoop tension on cooling. Couple that with some oil contamination (see rule #1) and you will get those radial cracks some days later which can really wreck you day at some time in the future. By softening, I do not mean that the plastic will get gummy. It just has to get warm enough to become stress free at the highest temperature reached.
Methylene dichloride (commercially shortened to methylene chloride), by the way, is not the cement, it is the solvent. You can use pure methylene dichloride to bond two pieces of Plexiglas together by allowing the surfaces of the pieces to be joined to dissolve (soak) in a shaped tray containing methylene dichloride. If injecting straight methylene dichloride works to join cracks, I would be interested to know. In another life, I made many Plexiglas underwater camera housings using the soak and join technique.
Acrylic cement, as I know it, is a solution of PMMA in methylene dichloride. Such a cement would carry additional PMMA into the crack for joining.
Also, methylene chloride can cause corrosion cracking of PMMA by dissolving some of the surface Plexiglas and causing cracks as the solvent evaporates.
There are no simple solutions. Marc Borom, 8/02
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3.2 Control Surfaces
These are the most important components of your plane! They are subject to the most stringent fabrication requirements in the whole plane. The reason is: concern for aero-dynamic flutter. The designer’s specifications and requirements must be kept in mind and certain balance criteria met to prevent in-flight flutter and catastrophic failure of a flying surface and probable death to the occupants.
During the initial flight testing of the plane, procedures are called out to verify the stability of the control surfaces. After those tests have been completed, any change in weight or weight distribution requires the balance and flight tests to be successfully repeated.
Safety of Flight Issue :
:If you remove or add any (read this to be even an ounce) of weight to the ailerons or elevators or sand any portion of the ailerons or elevators, or add or subtract any paint to any portion of the top or bottom surfaces, the designer’s balance criteria must be retested successfully. Flight testing in defined increments to Vne must be re-done to re-establish the stability requirements. This flight test data is to be recorded in the log book. Pay attention here. And you thought you wouldn’t need to become a test pilot. Failure to pay close attention to this will yield catastrophic flying surface failures and death to the occupants!! Is this clear??
Rule #3 :
:There are two sides to owning an EXPERIMENTAL aircraft. One is before you buy it and the other is after you buy it. Make sure you don’t buy the farm after you bought the airplane.
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3.2.1 Wing Trailing Edge Fences
Testimonial by– Tim (Flying Tiger)
(October 26, 2001): I installed a set of TE fences on the VariEze about 20
hours ago after talking with Klaus Savier about them. I think he was the first
one to install them permanently
on his VariEze. He claimed I would see a 10 kts lower approach speed with
much more aileron authority and he was absolutely on the money!
Previous to the trailing-edge fences my approach speeds were around 90 kts which makes for some long roll-outs after landing. I also found the airplane tended to start a very mild Dutch roll somewhere below my 90 kt approach speed but not anymore. The fences are a real significant safety improvement to our canards. I now approach at 80 kts and by short final I'm getting down to 70 kts with full authority.
The fences offer much improved aileron authority in all phases of flight including crosswinds. I also have not found any loss of top speed from the fences. I made mine out of 2 ply's of BID fiberglass cut in long triangles that extend 1 1/2 inches beyond the trailing edge of the wing and they are 3 1/2 inches from top to bottom on the back end. Mine extend about 2 1/2 inches above the horizontal of the wing and 1 inch below. I have seen them cut in triangles and teardrop patterns and both are affective.
PS. I did ask Klaus at Reno this year if they would work on Long-EZ's and he told me he had now tested them on the Longs and found the same improvements. The placement is a little different for the Longs.
For more information see: www.lightspeedengineering.com
Note: Canard stall, leading to high sink rate, is another limiting factor in approach-to-landing speeds. It’s one thing to maintain aileron authority at slower speeds, but yet another to have positive pitch control margin all the way to the tarmac.
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3.2.2 Vortex Generators
TYPE 1 -- The early Long-EZ’s used the GU canard airfoil, and it was susceptible to “rain fade”. When the plane would encounter moisture, canard lift would reduce, with a resultant loss in altitude without more pitch command input. The sensitivity to moisture varied from builder-to-builder, depending on imperceptible manufacturing differences. Some planes became “humidity sensors”, while others required only a slight pitch correction to maintain altitude in visible rain. This is the reason the Roncz canard was offered as a replacement design. Do you know what canard design you have on your plane?
Vortex generators have been installed by some builders to reduce the moisture-induced loss of lift. You will see this on some of the canards. The size, number, shape and location on the canard are critical elements. A thorough design, fabrication, and test flight program are the necessary steps to incorporating this modification.
TYPE 2 – Jim Price, working with the University of Michigan, developed vortex generators to increase slow speed performance of his Long-EZ in preparation for his successful world altitude setting effort (35,022 Feet, I believe.) In this case, Jim has vortex generators on the wings as well as the canard. However, the vortex generator placement on the canard is not the same as those used to reduce rain fade. Again, this requires detailed engineering knowledge and a carefully planned and executed flight test program.
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3.2.3 Long-EZ Aileron Rodend “Airwothiness Directive”
I have learned a lot about this mod since CP 103 first came
out. If you are going to comply with this CP, here are some hints.
First thing is, do not use HM-4's. Wick's has a rod end that has a 3/16" hole in the ball and is in every other way equivalent to the HM-4. This will save having to drill out all the bell cranks. Wick's part number is XM-3 (I know it doesn't make sense unless the dash number spec's the hole in the ball, but it is a 1/4-28 thread) They are $8.45 each, so the cost is a push if you consider the savings on the other hardware that can be re-used. Don't forget to buy new jam nuts, though. (Thanks to Ken Miller for this tip)
Second, check to see if you have the original CS-1 aluminum inserts or the later CS-50 steel inserts (usually attached with pop rivets). The CS 50 inserts are too short to rework, they just don't have the room to fit the larger, longer rod ends.
Last, Take your current push rods and measure the distance from the center of the hole in the ball to the insert side of the jam nut AS IT IS INSTALLED. The minimum it can be is .65". Shorter than that and the larger rod end won't be able to be adjusted down enough. Then measure from the insert side of the jam nut to the center of the head of the first rivet. Less than 1" must be added to the .65" i.e. center of ball to insert side of jam nut is .70", the minimum distance from the inside edge of the jam nut to the center of the rivet is .95".
Clear as mud right? My offer still holds, If you want to comply with the CP and you believe your current push rods can be retro fitted, I'll do the rethreading for free. Contact me at firstname.lastname@example.org for shipping info. -- Rick Girard 09/02
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3.3 Fuel Tanks
3.3.1 Fuel Leaks
Fuel tanks are integral to the airframe structure. Resin is applied liberally during the construction process to seal the inside of the tanks. However, once in a great while, someone will discover a leak. Strangely at first, the leak may propagate well away from the tank walls before the fuel finds itself visible to the owner. Capillary action can make the leak propagate to far away places, and even appear in the nose of the plane. You’ll ask, “What is causing that? There’s no fuel up there.”
One technique for diagnosis is to partially fill the leaking tank. Then tilt the fuselage at various angles and leave it alone for several hours to see if the leak appears at the exit point. This will take days to find the source of the leak, but it has shown to be effective.
And now the repair process. Of course, you will need access to the suspected area, whether it’s on the fuselage side surface or somewhere else on the tank surface. There went the paint job. And you will need to learn how to repair composite structures to finish the job.
Don't try to adhere Vinyl Ester resins to Epoxy resins. Although both are fuel resistant, resins bond best to themselves but not so well to each other.
Once the tank has been soaked in fuel, it is difficult to get most things to bond to the inner surfaces, even after sanding and abrading.
Recommend you buy some Pro-Seal - fuel tank sealant as used in aluminum tanks. This product has been specifically formulated for doing just what you want it to do, i.e. seal leaks.
It bonds extremely well and remain flexible yet fuel resistant. It comes in two grades, one grade is rather viscous and gooey to be daubed or troweled into place with an applicator stick. The other is brushable, and intended to be used to line the entire inside of the fuel tank. Take your pick based on what you want to do.
They are both about $40 - You will only need small portion, so don't plan on mixing up the whole container. You might look around for some RV builder that may have some left over from sealing his tanks. Or, you can sell him your leftovers.
First, remove all the garbage from previous attempts to seal the leak first. Scrape it, sand it, grind it, whatever, get rid of it.
As mentioned, the tank inter-skin is fuel soaked. It is highly recommend you find some way to allow it to dry out for day or two. This is especially important for the area you found is leaking. Any fuel weeping from the leak area will definitely keep anything from sticking -especially if was mogas.
Apply a heat lamp, from a distance or even just a 40-watt light bulb to warm up the surfaces and drive out any residual fuel. Don’t let it get too hot, no more than about 140F. As a rule of thumb, (perhaps hand) if you can hold your hand flat on the hot surface to the count of ten, the temperature is below 140F.
Allow it to cool back down before applying the Pro-Seal. That should do it.
EAA Technical Counselor
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3.3.2 Fuel Caps
Fuel cap quality generally has improved over the years. Early ones were held in place by a Zusz fastener. Some models employ the thermos bottle expansion technique. Still others are adapted from production aircraft or possibly from motorcycle fuel tanks. In any case, they should be tethered to the aircraft to prevent in-flight loss. Check your plane for the tethers. It is a safety of flight issue! When the cap departs the plane, there is a high probably that it will pass through the prop arc, catastrophically damage the propeller instantly, and a forced landing will follow shortly.
Fuel caps lost in flight have caused off-field landings and lost lives. Make sure the fuel caps on your plane are tethered.
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3.3.3 Fuel Gauges
Most all canards will utilize “coffee urn” sight gauges for all of the fuel tanks, left, right, and possible header. They are simple and accurate, if not hard to read. Because the original plans had you squinting to see through epoxy and several layers of fiberglass to read the fuel levels, many builders added white plastic backgrounds and a clear outer layer. The material for the visible portion of the gauge is made of plate glass or a non-crazing plastic. Inside the gauge, a piece of red material is supposed to float up and down with the fuel level. Sometimes, this indicator sticks to the side of the gauge and does not perform its intended function. A fewer number of builders found in-tank electric (capacitance) sensors and have the advantage of reading the fuel levels from gauges on the instrument panel.
a. Vance Atkinson still sells the clear gauges, and would have repair parts if needed. Email: Nostromo56@comcast.net
b. Wicks Aircraft and Aircraft Spruce and Specialty catalogs have the capacitance type gauges.
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3.3.4 Fuel System Debris Screens
Especially for plans-built
aircraft, there is an opportunity to get tiny pieces of foam into the fuel tanks
during construction. If you are a second owner, hopefully all the debris of the
building process has been removed by now. But, it still a good practice to
check the gascolator for foreign material, besides what is found may have come
out of fuel storage tanks.
The tanks should have screens located at the tank exits. These may be tea leaf strainers or copper/stainless steel screen door material that was floxed into place during construction. The important note is the size of material weave and what can be screened. The next opportunity to screen debris is in the gascolator. You will be checking that during each condition inspection, and at other times considered necessary.
If your engine uses an Ellsion Throttle Body Injector (TBI), there should be another filter that probably was adapted from an automobile. This one is able to filter out very small particles (70 micron) that could block holes in the TBI fuel nozzle.
Then finally, a very small screen – the last chance filter – is part of the carburetor or TBI. Repair parts are available from the manufacturers. Most will want to perform the maintenance to guarantee performance and keep warranties in place.
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4.1 Brake Calipers --The heavy duty brake calipers on the Long- EZ (caliper assembly 30-133).
Here are the parts numbers for the seals: All three part numbers identify the same o-ring.
Cleveland part number 101-05200 (not listed in Spruce catalog)
MS number MS28775-224 (also not listed in Spruce catalog)
AN number AN6230B-2 (this one IS listed in the catalog)
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5.1 Spark Plugs
Some cowlings are so close to the engine, especially #1 cylinder top, that you need to be careful that the spark plug and wire don’t rub. The popular Champion REM-37BY is a bit shorter and may help create some extra clearance. If your plane has an electronic ignition, the spark plugs have been specified by the developer.
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Oil Filters and Oil Cooling systems
Oil coolers are typically specified by the designer for the recommended engines. But, many builders use alternative engines that require them to find a suitable oil cooler. If your plane has a larger-than-specified engine, you can just about bet that oil cooling was an issue to resolve in the flight test period. Both the oil cooler capacity, the size of the connecting hoses, and its placement within the engine cowling are factors in how well it works. Stewart-Warner and Positech are typical cooler brands.
In an effort to mount the engines as far forward as possible for C.G. purposes, there wasn’t room for an oil filter in the stock position. Instead, an oil screen is used and requires additional maintenance as prescribed by the engine manufacturer. Alternative hook-ups have been developed to allow retrofitted installation of filters. Your plane may have one of these. The components for the oil filter may have come from stock airplane/engine combinations that normally use them, or from a small parts manufacturer that saw a business opportunity. You may even see automotive-style remote oil filter adapters installed, and they will also be of the remotely mounted variety.
B&C Specialty makes the adapter that fits on the engine, but turns the filter 90 degrees for firewall clearance. Wolf and the other developers remotely mount the filter with hoses attaching it to the engine. In any installation, use an aircraft approved filter.
a. Oil Coolers:
Aero-Classics at Pacific Oil Cooler’s web page: www.oilcoolers.com
Aircraft Spruce and Specialty
Positech International, Inc.
Other handy information (as of October, 2001):
|Oil Cooler||Model Number||Cost||Heat Transfer||$/Heat Transfer|
b. Filter adapters:
B&C Specialty, Newton, KS:
Vernatherm Valve Operational Inspection: The Vernatherm is stamped with the operating temperature on the back. Usual 85 Deg C (185 Deg F). It will operate by expanding... lengthening to close off the hole in the engine and redirect the oil flow to the oil cooler. How far does it lengthen? About 3/8". You can get it to expand using water BUT, use oil it is more stable than water for stove top heating. Also use a thermometer to check the oil temperature. You can use a simple basting thermometer (Cooking type with a pointy probe... Ask you Wife!) Inspect the dome for wear and ALSO inspect the engine where the dome fits into. Next inspect the crimp end nut to make sure it is secure. There is an AD against the OLD model for an inspection. The New model has a roll pin through the crimp nut on the end, ergo no AD.
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This is a subject area where you will see a lot of variations from plane-to-plane. The propellers used on most of the canards are fixed-pitch and made of wood or a combination wood/fiberglass – Notice there are no canard pusher planes with metal props, because of unknown metal fatigue issues. Some Velocities and Cozy’s have variable pitch propellers, and some highly customized performance machines will employ carbon fiber material. Most props are produced by very small companies – maybe one person – and require technical skills to design and artful work to fabricate. For the Rutan aircraft, Burt dictated wood, as it was the lightest and most tolerant of the unknown structural forces encountered at the rear of the experimental aircraft.
Propeller damage is usually caused by something in front of the propeller finding its way through the prop arc while it’s turning. Runway stones are picked up and damage the painted surfaces. Errant cowling screws are a favorite to leave a gouge. Fuel caps and broken exhaust pipes have been known to break a blade with sometimes-catastrophic results. Even a few valve pieces have departed via the exhaust pipe and cause severe damage. Longitudinal splitting may be caused by some of the above items, but blade flutter and ground handling accidents can do it too.
Your task is to know the materials of your propeller and to take care of it appropriately. Small dings and scratches through the finish need to be repaired immediately. Otherwise, oil and other contaminants will infiltrate the structure to discolor and weaken it. Inspect the blades for longitudinal splits and gouges before every flight. Some splits can be repaired. Some can’t. If you find one, ask someone knowledgeable about an acceptable repair technique.
NOTE: Clear finish urethane paint is an acceptable repair material for scratches. A mixture of cotton flox and epoxy resin is suitable for filling repairable small gouges. Repairable splits can be repaired with epoxy resin possibly.
In your Operator’s manual
and/or the prop manufacturer’s information, you will see a requirement to
re-torque the prop bolts periodically. Seasonal humidity variations where
the plane is based, altitude/humidity influences, and trips to varying climates,
cause the materials to shrink and swell. Perform this maintenance item
religiously. At the time of the annual condition inspection,
remove the propeller. Check the finish around the hub for discoloration, charred
areas, crushed wood, and material migration. This will indicate how well the
prop bolts were torqued. Refinish if necessary before re-installing.
Rain erosion is another issue with wood propellers. Many have leading edge protection to protect the wood. Some may not have anything but the painted finish. So, if you fly in rain, reduce the engine RPM to reduce the damage to the prop leading edges.
Note: Measure across any set of opposed holes in the prop flange center to center. If it's 4 3/8", it's SAE 1. If it measures 4 3/4" it's SAE 2.
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6.1 Propeller Manufacturers
Prop manufacturers can usually be identified by the shape and materials of their propellers. Only a few have the manufacturer’s name posted on them. Here are some of them:
Bruce Tifft, now deceased (typically 5-ply wood laminate, clear finish) These are flown on the VariEze and Long-EZ mostly.
Lightspeed Engineering, Klaus Savier, (typically large diameter carbon composite) These will be seen on the Berkut and a few Long-EZ’s and on Klaus’ VariEze.
Great American, company no longer in operation (typically, 16- to 32-ply wood laminate, clear finish) Mostly found on Long-EZ’s and VariEze’s.
Catto Propellers, (two and three-blade wood core with fiberglass outer layers, painted finish)
Performance Propellers, (two and three-blade wood laminate, clear finish)
Sensenich Propellers, An old line wood prop manufacturer, but not normally seen on canards
Ed Sterba (2-blade, wood laminate)
Prince P-Tip Propellers (2-blade, composite, P-tip, painted finish)
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Fixed/Variable Pitch Propellers
Most all of the canards utilize fixed pitch propellers for the reasons mentioned above. Other reasons involve engine modifications or electrical circuitry for pitch control. All this adds to aircraft weight. Follow the manufacture’s specifications! The performance of these planes is excellent as they are.
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6.3 Material – Metal or Wood Composite Propellers
In our EXPERIMENTAL aircraft, you don’t want to experiment with the things that push the plane forward and keep it flying. The propeller dynamics at the rear of Rutan-type aircraft have never been analyzed sufficiently to understand the vibrational forces that must be withstood by the propeller blades. Wood or wood/fiberglass material is more tolerant of these unknown forces and is therefore prescribed. Metal propellers are unique to each airframe/engine combination and undergo testing that is not possible for a Homebuilt.
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6.4 Wood Prop Care
(Compilation of Information from Bruce Tifft for his propellers)
Apply a light coat of beeswax or paraffin wax to drive lugs and center spud extension. Care should be taken to keep propeller hub face parallel to the flange face while tightening the bolts. DRIVE LUGS ARE A MUST!
Torque to 250 inch pounds and check after the first flight is completed. Recheck every 10 hours until completion of 50 hours of flight time on your new prop. Then, check torque every 25 hours.
Carefully track your propeller. Get it perfect. Do not settle for 1/16" being close enough. Tighten all bolts to 250 inch pounds. Check track. Back off the three bolts on one blade and continue to tighten other three up to 350 inch pounds, each time tightening the other three to 250 inch pounds until it tracks perfectly. You will be happy with the smoothness you will gain.
Place a stick on wing held in place with a bean (shot) bag. Align stick one inch from end of prop. BE SURE MAGS ARE OFF AND PROP TORQUED TO 250 INCH POUNDS. Rotate prop to determine if prop to stick gap is equal and track is equal. If not tracking exactly, a slight variation can be corrected with differential torque on lugs until in line. If track is too uneven, a piece of folder stock may be used as a shim between prop flange and prop face to even up track.
Check if crank flange is bent. Remove prop, rotate 180 degrees, then replace prop. If opposite end of prop is now farthest from stick, you have a bent crankshaft or bent flange. Both are expensive to correct.
When finished, be sure proper torque (250 inch pounds) is maintained on all lugs.
Always leave a wood prop in a horizontal position when you park your plane. It draws moisture to the bottom blade if vertical and will vibrate until weight is equalized. If you do not fly for a long period, rotate the prop 180 degrees occasionally.
Automotive paste waxes can be used to clean the finish. No other care is necessary.
IT IS ESSENTIAL THE CENTER HOLE OF THE PROP BE COVERED. If you are not using a spinner, use an aluminum plate under your crush plate or moisture can soak in the center hole and damage the hub area.
(MAH comment: Since 1992, I have used a wine bottle cork in the center hole with excellent results. It weighs less than a plate. If aircraft is parked on ramp, sun and weather will take their toll. Cover the prop to protect from sun damage while leaving room for ventilation.)
Light impact damage can be repaired with two part epoxy filler available in tubes. Always carry JB Weld or a Duro epoxy kit. Fill small chip holes and small voids, clamp with a rubber band until cured, and sand the hardened epoxy to fit contour. Although the epoxy is very dense, the amount of imbalance resulting from small repairs is negligible.
PLASTIC LEADING EDGE:
This type of leading edge is effective in preventing small rock damage, and if damaged, is easy to repair with JB Weld. However, rain and hail can cause serious wood damage. When entering rain, decrease the RPM as much as possible because rain can damage the wood behind the plastic. At idle, little damage, if any, will occur because the prop is not creating thrust or drag. In rain, hail, sleet or snow, throttle back and save your prop.
PAINTING OUTER TIPS:
If you wish to paint the outer three or four inches of the tips, make sure an equal amount of paint is applied on each side to maintain the balance of your prop.
SAFETY OF FLIGHT ISSUE: Propellers are held onto the prop extension by six bolts. The properly torqued bolts apply a prescribed compression of the wood material within the yield strength of the bolts. It’s friction that keeps your prop on the airplane, not shear forces on the bolts. Wood propellers breathe, or swell and shrink with humidity changes. It is therefore imperative that you follow the manufacturer’s recommendations for periodic re-torquing of the propeller bolts. Even flying from one climate to another may trigger the requirement to re-torque the bolts.
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7.0 Electrical System
Burning (or smoking) insulation will typically release toxic fumes.
PVC: Incomplete combustion (smoking wires) gives, carbon monoxide and hydrocarbon oxidation products including organic acids, aldehydes and alcohols. Flash Point: 806 F (this is for one type of PVC, others are similar) (Flash point is when it starts to actually burn. FLAME)
Please refer to NASA selection guide for insulation material http://www.nepp.nasa.gov/npsl/Wire/insulation_guide.htm
FEP and PTFE Advantages:(Dupont TM Teflon)
-Excellent high temperature properties.
-PTFE Teflon is preferred for solder applications.
-FEP is preferred for jacket material.
-Good out gassing characteristics
-Most flexible of all insulations
-Good weather ability, resists moisture absorption and atomic oxygen erosion
Teflon does breaks down when at HIGH temperature and releases hazardous byproducts. (The temperature that would cause Teflon to break down would probably be the result of some other material burning)
I have seen an industrial panel with teflon and pvc following a short circuit failure. The PVC panel had secondary wiring melt and additional cascading failure (The entire inside of the panel burned). The teflon had a group of wires damaged with NO resulting fire.
It would be better to design you electrical system to prevent short circuits from causing fires. A well designed and protected electrical system has very little chance of causing a fire.
Teflon is a better choice in by opinion. -- Dennis Blomquist, 9/02
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For trouble shooting help, this web site may be of assistance. http://avionicswest.com/snap.html#Alternator%20Noise
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For wiring or re-wiring your airplane, here are recommended procedures and tools from one of the most knowledgeable people in the general aviation industry, Bob Nuckolls. Subscribe to his Aeroelectric connection publication (http://www.aeroelectric.com).
RULE 1: First choice for joining/terminating any wires up through 22 through 12AWG are PIDG style terminals as described in http://www.aeroelectric.com/articles/terminal.pdf using tools like found at http://www.aeroelectric.com/Catalog/tools/tools.html#rct-1 or better.
RULE 2: Where there is a choice, I would select fast-ons over threaded fasteners in the 22 to 12 AWG range using terminals like found at http://www.aeroelectric.com/Catalog/wiring/wiring.html #faston with features as explained in http://www.aeroelectric.com/articles/faston3.pdf.
RULE 3: When I have to live with a treaded fastener then these terminals are in order . . . http://www.aeroelectric.com/Catalog/wiring/wiring.html #s816p
RULE 4: For wires larger than 12AWG, then I would solder and heat-shrink joints as described in . .http://www.aeroelectric.com/articles/big_term.pdf using materials like . . . http://www.aeroelectric.com/Catalog/wiring/s812.jpg, which are supplied with double-wall heat-shrink for finishing. RULE 5A: Permanent splicing of single conductors to be accomplished with butt splices like . . . http://www.aeroelectric.com/Catalog/wiring/s816.jpg
RULE 5B: but if it was deemed desirable to break the splice open for future convenience, a knife splice and heat-shrink would be used thusly . . .http://www.aeroelectric.com/Catalog/wiring/ksplc2.jpg
RULE 6: When the accessory items are supplied with nylon connectors like AMP Mate-n-Lock or Molex, pins are installed with a tool like . . .http://www.aeroelectric.com/Catalog/tools/tools.html#bct-1 used thusly . . . http://126.96.36.199/articles/matenlok/matenlok.html These connectors would only be used as an accommodation for the use of an accessory that comes with them already installed. They are not my connector style of choice for any other applications.
RULE 7A: When working with accessories supplied withD-sub connectors, the first choice of mating connectors is the removable pin variety that will accept machined pins like . .http://www.aeroelectric.com/Catalog/connect/connect.html#S604 installed with a tool like http://www.aeroelectric.com/Catalog/tools/tools.html#rct-3 and removed with a tool like . . .http://www.aeroelectric.com/Catalog/tools/tools.html#dse-1
RULE 7B: if for any reason the crimped-pin mating d-sub is not available, then soldering is my second choice using techniques described in . . .http://www.aeroelectric.com/articles/dsubs/d_solder.html and tools like http://www.aeroelectric.com/Catalog/tools/tools.html#s101_1or better
RULE 7C: If options 7A and 7B are not practical, then the lowest order choice for working with d-subs is open barrel crimped pins installed with a tools and techniques like those described in RULE 6.
RULE 8: Installation of connectors on coaxial cables to antennas are installed perhttp://www.aeroelectric.com/articles/bnccrimp.pdf using tool . . http://www.aeroelectric.com/Catalog/tools/tools.html#rct-2 and wire . . . http://www.aeroelectric.com/Catalog/antenna/antenna.html#rg-400 and connectors . . . http://www.aeroelectric.com/Catalog/antenna/antenna.html
RULE 9: A single point ground system shall be established behind the instrument panel with sufficient attach points for all accessories in the cockpit area. In deference to RULE 2, a forest-of-fast-on-tabs ground block similar to . . .http://www.aeroelectric.com/Catalog/wiring/wiring.html#gndblk. The threaded stud on the ground block assembly would penetrate the firewall and be used to terminate battery (-) leads on either side of firewall and the crankcase ground strap on the engine side of the firewall. In the case of canard pushers with the battery up front, the ground bus would be mounted forward of the instrument panel. If the airplane's firewall is metallic, then a brass bolt and appropriate washers and nuts would be used to provide an engine compartment ground stud and connection of the ground lead to the firewall. A ground strap like . . . http://www.aeroelectric.com/Catalog/wiring/wiring.html#bbs will be used to connect the crankcase to the firewall ground stud. Any ground straps provided around the rubber biscuits of an engine mount will be removed. Engine mounts are for holding engines on airplanes and not use for any part of the electrical system. RULE 10: Tefzel wire used throughout with the exception of engine cranking circuit fat wires where 4AWG or 2AWG welding cable would be used. An alternative FAT wire could be one of the new copper-clad aluminum wires. These new materials are as solder-able and crimp-able as pure copper conductors.
Caution: To get the same electrical performance, you need to use about 2AWG steps larger wire than for copper but the installed wire will still be lighter.
Here endeth the reading of the rules. In parallel universes there are differing rules which may well prove to be as useful or perhaps even better than those cited in Bob's universe. Given what Bob has learned up to and including Sunday, October 27, 2002 the rules cited above are his personal choices for practical, solid techniques using moderately priced materials, and tools. Adherence to these rules is likely to produce an electrical system where (1) component wear-out and failure are the sole causes for maintenance and (2) the wiring can be expected to perform as intended over the lifetime of the airplane. - Gary Hall, reporting for Bob Nuckolls
Terra Transponders -- Free flight Systems stopped upgrading TRT 250 in 1998. No avionics shops have been found that will do the upgrade. Free Flight Systems said the reason they don't upgrade the TRT 250 is the problem thumb-wheel switches. They did agree (thank you Free Flight) to send parts to do the upgrade. So, if you are able to make the modifications yourself, this may be a solution.
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You will find these used as the Master Solenoid (continuous duty) and another as the engine Starter Solenoid (momentary duty). The momentary or continuous use criterion is important. The ratings specified typically refer to the amperage that can be "switched" without welding the contacts together and/or overheating the solenoid coil wire. (When the contacts are closed, they will handle the currents required for engine starting.) I prefer to use the continuous duty in both applications for reliability. The vast majority of planes use 12VDC systems, so the auto parts store is a good place to find this device. Here is one suggested source: Contactor/Solenoid: Buy at an RV dealer or auto parts store, a continuous duty, sealed contactor, metal grounded case, 85 amps continuous service. Cole-Hersee part number 24106. The predominant failure mode for these relays/solenoids is from moisture getting in under the Rolled/Crimped top. The BEST thing you can do before installation is dip them in epoxy paint to seal them from moisture. 10/02
8.1 Brake Fluid –
Some aircraft use DOT 3 brake fluid (red in color and common in automobiles) and others utilize DOT 5 (clear Silicone). The apparent reason for the shift to silicone is to reduce the probably of fire when the fluid comes in contact with a hot brake disk. However, is it not a simple conversion from one type to the other. Read the following notes on the process and precautions.
1. DOT 5 Silicone should not be mixed with other brake fluids that are
2. If you change from a glycol-based fluid to DOT 5 Silicone, you have to
flush the brake system thoroughly as already suggested, and also replace all
the rubber products in the system which have absorbed the glycol-based
3. There is a DOT 5.1 brake fluid that is glycol-based, not
silicone-based. Be careful.
4. DOT 5 Silicone was developed to reduce water absorption, and therefore
increase the length of time between brake fluid flushing and replacement.
Glycol-based brake fluid should be replaced every 2-3 years. Silicone-based
is much longer.
5. The "red stuff" is MIL 5606 or a replacement such as Chevron Aviation
Hydraulic Fluid A. It is petroleum-based. It is commonly used throughout
an aircraft and its viscosity remains relatively constant over a wide
temperature range, including down to less than -65 degrees F.
If you mix a large amount of DOT 5 Silicone with a small amount of Red Hydraulic Fluid, you get horribly sticky goo.
When changing from Red Hydraulic Fluid to DOT 5 Silicone, you have to flush the system well, and replace all rubber products in the system. There are no problems with putting DOT 5 Silicone in a new system. It would be wise to label the reservoirs "DOT 5 Silicone only".
DOT 5 Silicone was originally developed for the U.S. Military to reduce the need of changing the fluid to once every several years - I forget exactly how many. Red Hydraulic Fluid should be replaced about every two years because of water absorption. --Garth Shearing, Victoria BC Canada
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8.2 Long-EZ Nose Wheel Axle Bushing Rotation
There are two aluminum spacers on the Long-EZ used to center the nose wheel between the forks. These spacers tend to spin and cause inappropriate wear. It’s easy to stop the spinning by pinning the spacers, but the bearings’ inner races may be spinning on the spacers too. To correct both problems do the following:
This method is exactly the way wheel bearing pre-load is done on a Harley Davidson motorcycle. It works great, and it’s recommended to use Harley's method for setting end play tolerances. Fabricate a center spacer to fit between the ones on the wheel assembly. Clean the bearings thoroughly, assemble the wheel, bearings and the three spacers with no grease in the bearings, and use a dial indicator to check end-play. Harley specs .004 - .016" (.1 mm - .4 mm). A Long-EZ builder recommends going for as close to 0.004" (.1mm) as you can get. When you're satisfied disassemble, grease the bearings and reassemble. Good to over 100 mph with no wheel wobble, says the builder.
To pin the spacers, drill a small hole in the fork that penetrates the spacer. Tap this hole for a tiny screw long enough to go through the fork and into the spacer. Or, another method is to cross-drill the spacer perpendicular and off-center from the axle hole. Use 0.040 safety wire through the hole and around the fork.
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8.3 Long-EZ main gear attachments/hard points
The best installation is with a flanged bushing, with the flange faces mating against the landing gear "support tube" (for lack of having that part number at my fingertips). The flange faces "face" each other when the extrusions are installed in the fuselage.
The bushings needed for this are P/N NAS77-6-25, which are a steel bushing with cadmium plating. For the hole in the mount, you will need to precision ream the hole for the bushing to 0.5000 inch - if you don't have a good 0.5000 inch reamer, take your extrusions to a machine shop - they may charge you a
six-pack for such an involved procedure...
The bushings are a press-fit (can be installed in a vise), with an outside diameter of 0.5013. If you have the opportunity to install these bushings with a wet coat of a good epoxy-based primer on the bushing OD, all the better. The primer helps a bit more on the corrosion side of things. Chromate-based aircraft sealant also is a good option. I used JB Weld the last time I made up a set of Long-EZ mounts. Mind-you, there is no reason to seek something for bushing installation with the thought of "bonding" the bushings in - the interference fit between the bushing and the extrusion is what is important. The 0.5000 reamed hole is essential.
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8.4 Tire Inflation Technique
Go to your local truck terminal or a major truck stop with a truck
accessories store. Buy a six-inch long valve extender and a set of hex-head, steel valve caps. The truck valve extender should have a hex-head socket on the female screw on end. Use the extender like a socket wrench through the hole in the wheel pant to remove (and replace) the hex-head
valve cap. The truck valve extenders are like long Schraeder valves and make filling of the tire a snap.
To speed up the process, place a visible mark on the outboard side of the tires to indicate the position where the tire valve lines up with the hole in the wheel pant. – Bob Eckes
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9.0 Refueling – Static Electricity Protection
Marc Borom -- After moving from NY to AZ, I was very concerned about the increased danger of static electricity sparks during fueling my electrically non-conductive plane. I talked with the GE scientist in charge of protecting polymer mixing vats from static electricity induced explosions. Here is the skinny.
The worst case is when one pours a non-conductive liquid (like gasoline) from a non-conductive
container (like the red plastic containers many of us use) into another non-conductive container
(how about like epoxy coated fiberglass wing tanks). Low humidity (like in AZ) makes things worse.
A static electrical charge builds up on the surface of the flowing liquid as it rubs along the non-conductive nozzle, and it is always looking for a place to discharge (the gasoline/air mixture in the fuel tank is the KaBoom site). Even if you are fueling from a grounded fuel nozzle, the non-conductive gasoline will pick up a static charge just by falling through the air (turbo-static charge). So how do you protect yourself from the KaBoom syndrome??
This is what I was told. One must devise a technique to strip the charge off the falling liquid before it can jump a spark. On the advice of the Anti-KaBoom scientist, this is what I did, and, so far, no KaBoom.
I went to Home Depot and bought a 1 ½" x 12", flanged brass tail piece for a sink drain (Moen #803B
for $4.47). I cut a slit along the axis of the tail piece from the flanged end for about 8 inches (long enough to clear the fuel cap locking wire and to allow the tail piece to be inserted in the fuel tank).
The flanged end rests on the bottom of the tank. I chose to have the flange rest on the bottom of the fuel tank to minimize scuffing of the tank surface. A grounding wire is bolted to the top of the tail piece (the tail piece can be cut to an appropriate length less than 12"). I used 12 gauge, stranded copper wire for the grounding lead with an alligator clip on the end for attaching to a good earth ground.
Fuel is allowed to flow along the tail piece’s internal surface and any charge is transferred to ground. Do not use an aluminum tube for the charge stripper since aluminum oxidizes readily and the oxide layer will insulate the fuel from the ground.
Attaching the fuel hose nozzle ground to the exhaust stack does nothing for you. Remember that it is the fuel rubbing against a non-conductor and just plain falling through the air that is the problem. The tank insert nips the problem in the bud. The whole tail piece device will fall to the earth if you throw it in the air, but it weighs less than 8 oz.
Note: Ed: I think this is the definitive re-fueling static protection technique. Not withstanding the relatively small amount of fuel we usually transfer to a single tank and the resultant reduced opportunity to build up a static charge, this technique is as fool-proof as it gets.
More on this subject:
I've re-read through all these static and fuel related posts on the Canard board and Cozy boards. Let me see if I can summarize things, there's multiple problems and solution steps needed.
Static potential on:
- fuel surface within the tank,
- exterior aircraft skin,
- fuel falling into the tank,
- your clothes,
- that thunder-cell within 10 miles
What's the likelihood? Sparks and fires have happened multiple times with EZ airplanes.
1) Regarding "grounding the fuel within the tank"... I'm seeing "metal cap & filler ring with dangling chain" and Marc Borom's solution. These are to be grounded with an external grounding wire, FIRST CONNECT AIRCRAFT, then connect ground. Also, there's at least one EZ with an internal grounding wire running from the metal filler ring & cap, thru the tank wall to aircraft ground. He can ground on the tail-pipe.
2) Regarding "falling fuel"... I think Marc Borom's approach specifically addresses this, although I still can't fully visualize it, yet. Does this address refueling from a plastic jug?
3) Regarding "static potential on external aircraft skin"... This isn't always resolved with a "grounded cap & filler-ring with dangling retention chain". The solution for this is to wipe down the surrounding surface with a damp cloth or use a "anti-static pad" as shown on the recent "Lindberg crosses the Atlantic in Lancair"
4) Regarding "bad grounding sequence"... If you externally ground your filler-ring & cap (as opposed to a built-in internal grounding wire), have a personal grounding wire. YOU connect first to aircraft then to ground. If you have an internally grounding wire from the filler-ring & cap to aircraft, the tail-pipe will do.
The refueling procedure is to:
1) Be aware of and take action regarding static buildup in your clothes. (dry with static-cling strips, strip or cover static-y things)
2) Be aware of lightening potential conditions. Lightening does hit and kill people 10 miles from the nearest cloud, almost annually in Colorado but less now with global warming.
3) YOU! connect your personal grounding wire, firstly to the metal filler ring, secondly to ground. (if you're using Marc Borom's solution, skip to next step)
4) Wipe the aircraft skin widely around the filler port with a damp rag or throw on an "anti-static pad"
5) Open the gas cap.
6) If you're using Marc Borom's solution, insert and ground.
7) Keep the fuel nozzle against the metal filler ring at all times.
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10.0 XPDR Codes -- For filing flight plans:
Cozy = COZY,
Defiant = DEFI,
Solitaire = SOLI,
VariEze = VEZE
Long-EZ = LGEZ,
Velocity = VELO,
Berkut = BKUT
VariViggen = VVIG.
There are other designations such
as RV6 etc., but just those for the composite canards are included here.
If in doubt, these general codes apply: HXA for cruise speeds less than 100 KIAS,
HXB for cruise speeds 100 – 199KIAS,
HXC for those with cruise speeds above 200KIAS.
These are from recent changes to the FAA controllers’ handbook. A lot of controllers do not know much about
homebuilts, and they may ask what type you are.
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