thjakits

Jon, AFAIK there was no one who has a deposit that is not refundable.... Might be wrong though.... Brine, the Airjeep is REALLY ugly.... thjakits

Jon, the Atlantica "flew" a lot in X-plane. I know its in the PC, but on the other hand it is a really good tool for prototyping. Atlantica had a test-accident, because the owner/designer/testpilot gave in to pressure from the money-side and did highspeed taxi tests in too much wind. At some point the plane got airborne in a gust and because of overcontrol it came down pretty hard. Analysis actually showed that it flew better than expected - that's where the intended control inputs where too much, as they did not match with the flying qualities at this time. However that was to be tested. There is nothing wrong with the plane at this time, just has to get together again and fly - time and money. The theory - x-plane and CFD check out well.... Question is the price at the end.... Avanti: So you say the elevator always produces some downforce on the Avanti? thjakits

Hey Brinesharks, You are right about blackboxes and the unskilled labour thing....) Still would like to know what's a brineshark ) Actually a shark?? Flying wings eh? Which ones to you prefer? Straight wing like Fauvel, Maerske, etc. or Horten type - Horten IX is the most beautiful Flying Wing I ever saw!! Most likely you also know about Wingco and their Atlantica BWB... If you have any info of forums about Flying Wings and/or BWB let me know. What I googled up so far is not worth the time... Also 3-surface planes like the Piaggio Avanti are on my favorit list. I may be wrong, but I think the Avanti has all lifting surfaces, non pulling down like a conventional elevator. I wonder if that kind of configuration has any merrit in a 1- or 2-seater size... Long-Ez: You are right about doing the math thing first. Here is the plan: a) Find the time - sometime down the road b) Play with X-plane and aircraft-PDQ (DaVinci) c) Maybe try a RC-model (if my kids like RC....) d) See whether the BD-4 is still #1 one in a reality check e) Build the real thing Best Regards, thjakits

brinesharks! (How the hell did you make up this name? )) Okay, I would say to "compare" the Long with a Eurofighter is a long shot, but definitely worth bragging rights! Seriously how a definitely un-stable, supersonic, fly-by-wire fighter works is not comprehensible for a human brain (mine at least...) you look at video-clips of fly-by-wire planes you see control surfaces go any and all ways but what you would expect. E.G. Pulling back on the stick, doesn't necessarily mean the elevator goes up. What it means the "pilot would like the plane to behave as if the elevator goes up in a direct-analog /mechanical/hydraulic/electric controlled plane" Actually I saw clips of a F-18 where one elevator goes up and the other down, so there might be "aileron" mixed in there too.. Of course the idea of a movable (full flying or only incidence trim) canard is to push the top speed/reduce canard-lift induced drag. YOU CANNOT "forget" about increasing it (incidence angle) again when slowing down! I imagine there would be various ways to ensure this. Any of these ways restrict the rear travel of the joy-stick. This way you cannot pull enough "elevator" to get the wing to stall. When you increase incidence to the established angle, the stick is free again to go all the way. If you insist to fly with low incidence, all you do is go faster - well you'll find out eventually that you cannot slow down to where you are used to. In any way, this is NOT for the basic, lowtime sunday afternoon flier, but for the "experimenter" looking for the last pit of performance. If you are that kind of guy you probably use a checklist anyway... My question is more about finding numbers and devices (mechanical) to do this safely... thjakits

Thanks for the reply! My idea to build a Vari or Long is not to get a cheap and fast airplane fast, but to enjoy the building "the best/slickest/fastest" I can. I make a living flying, so this is not the concern for me.... So if laminar would bring a few kts I would try it, however the goal is not loosing any low speed properties... To the canard: Why should a trimable canard be unstable?? The canard itself is stable, isn't it?? So my rational (..which may not be rational after all ) is - If high CL at max speed is not trimmable by elevator only, why not change the incidence angle (?). IU the max CL causes a high AOA that is not trimmable by elevator any more and needs excessive stick-forces.... This would probably be a rather small amount (3-8º ??), It also can be a slow electric-motor or a long (manual) handle with little effective movement on the canard. If the canard is stable it should not become unstable by changing the incidence. To protect against "un-intended" stalls on the mainwing one could limit the aft-stick movement with application of lower incidence. So pulling aft will only generate a faster minimum speed. Increase incidence (Return Canard to original setting) and one gets the full range back.... I do understand that things get more complex here, but I wonder what the benefits regarding speed would be. Ever anyone tried a full flying canard? Best Regards, thjakits

Hi all, anyone read a discussion on the Cozy-newsletter about eliminating all rain trouble and vortex generators by sanding the canard? Here a (shameless) copy, thanks to the Cozy-newsletter!!: GU CANARD TRIM CHANGE (Nick Parkyn) "It is proven and accepted that a trim change occurs in rain or when condensation forms on a canard which uses the GU airfoil (used on early Rutan Canards). There are accepted solutions to the problem, including the replacement of the canard with one using the Roncz-designed airfoil. The paper A review of low Reynolds Number research at Glasgow University by Galbraith and Cotton of the Department of Aerospace Engineering at Glasgow, suggests that, when they became aware of the real world problems with the GU airfoil-based canard, further research was done. The reduced performance in rain was primarily a result of water droplet formation on the high gloss surface of the canard. If the surface finish had been matt, the associated modification in surface tension effects would have ensured a more even distribution of water over the surface of the airfoil, so retaining its original shape and performance. If you apply this concept by removing the high gloss finish from the surface of the GU canard with very fine wet and dry sandpaper, using only a chord-wise rubbing action, you will achieve the suggested matt finish without destroying the potential for laminar flow." GU CANARD TRIM CHANGE The note from Nick Parkyn that we published last newsletter about the GU canard was in our newsletter file quite a long time. It sounded so illogical, we were reluctant to publish it. Shortly thereafter we got a letter from Marc Pichot: 10/4/99 Dear Nat, When I received newsletter #67 (about sanding the GU canard to correct the trim change in rain) I removed the vortex generators and began to sand my canard chordwise with 400 grit wet paper. On 10/2/99 my canard was totally sanded. Same day outside it was raining cats & dogs, so I pushed FMP out of the hangar. I was afraid to take off because of poor visibility, but decided to do a taxi test. At 50 kts, the canard was flying. The 5,600 ft long runway was sufficient to make 3 trials with a 20 kts wind. Back at the hangar, I asked my friends what they noted. They said the angle of attack was 10 degrees easily. So, when the visibility improved, I did another test and flew about 1 meter above the ground. No doubt, the canard was performing far better than with the vortex generators. The V.G. solution is a stopgap compared to what I noted today during 95 minutes and 3 landings. On take off, the power of the stick is double. Takeoff was at 65 kts, climb in clear sky is better than 1500 ft/min (remember, my engine is an 0-235 C2A). Level at 2000ft with 2450 rpm speed is 145 kts indicated, and 5 to 7 kts more than previously. At 2600 rpm, 150/155 kts and it is impressive. Then flying through rain, trimming is so easy that I will never install vortex generators on the canard again. I have V.G.s on the main wing ahead of the ailerons. I will try on the wing what I did on the canard. Aerospatiale is working on this to reduce the drag on the Airbus A340. On landing flare was good before, but seems better now. I get excited like a flea on a fat dog during this flight, and upset against the Glascow University guys to give us THE SOLUTION after 15 years of use on Rutan aircraft! Marc Pichot Pont l'Abbe France Best Regards, thjakits

Hello all, I am new to this forum - my present "plan" is a Modified BD-4 with a Rotary Engine. However lately I keep thinking of a Long-Ez "kind of plane": I have a few questions I could not find answered in the archive: # AFAIU the Vari-Eze has a laminar mainwing section and the Long a turbulent one - consensus the Long is easier to fly (?) Did anyone ever try a Long with a scaled up Vari-section? Laminar should be better erformance/speed (?) # AFAIU one speed limit is the excessive lift on the canard at max speed - Did anyone ever try to build a trim-able canard? If one can reduce the incidence, max CL should be lower on the canard and max speed should go up (?) Please correct me anywhere I am wrong or at least point me to the right place to find the "truth" Thanx, thjakits )

How about a Vari-Eze: Recline seat to 37º Move engine forward if you can, reinforce engine-mount if using a monsterengine (Mazda Rotary 2-rotor, turbo, and whatever you like) which you can do now that there is no pax retracts, pax weight differently invested If you can't move the engine, use the rear seat space for fuel and luggage Have some pro work the plan, maybe you can push Vne. Still, make the cockpit a little wider - so you can scratch the outside of your upper arm - normally squeezed into the Vari-eze ) Single seater plus: You don't have to give rides!!! ) Single seater minus: You can't give rides!!! If you are not stuck with a canard, consider a BD-5 or a Taylor Mini-IMP Best Regards, Thomas, dreaming about BD-4 with mods.... ......lately drooling over canards like: http://www.ez.org/feature/F0502-1/F0502-1.htm .......more drooling over a slightly modified Polen Special .....most drooling over: http://www.wingco.com/ Blended Wing Body / Flying Wing and imagine single seat versions of it!! )