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About langted

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    Active Member
  • Birthday 11/12/1956

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    Citabria 7ECA
  • Location
    Lambertville, MI
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  1. Yes indeed, protection for hoses! Fire barrier 2000+ looks like a reasonable choice, available, and not extremely pricey. FWIW: My engine is a Titan 340 (experimental) with vertical induction, Airflow Performance fuel injection, and twin E-mag electronic ignition. I went with low compression pistons since I don't trust the future fuel options. I will be using a Prince fixed pitch prop. Great props and built locally. I can literally ride my bicycle to Prince Propellers. The Arion Lightning was really designed originally for a Jabiru 3300, and perhaps I should have stuck with it (the kit is more complete if that option is used, and there is a lot to be said for the Jab. However, market penetration in the US is much stronger with Lycoming clones, and of course I have more horsepower with this option.
  2. Dave: Here are a few. Just like yours, except trip home. Classic Arion photo while being flipped over after wing and tail mount (about day 3) Last time the wings were fitted, on mains, canopy in place, flaps, ailerons, but no elevators/rudder (about day 5) Getting ready to go home, day 7. (No, not tailwheel, just no place for training wheel yet) Arrived home, in shop (also showing forward flange without firewall)
  3. Dave:. I did about 7 days of build assist. I wanted to get major structures done and the canopy, then trailered it back home. I'm surprised you don't have yours yet -- hope it's worth the wait. My fuselage arrived a little late, and (long story) I ended up with an epoxy fuselage instead of vinyl ester. Anyway, Nick (for others, Nick is the Arion Aircraft owner) worked with me over Saturday to catch up the lost time. I've never posted pictures on this forum, but I'll add a couple once I figure it out.
  4. M61A1: Thanks for the link. That link suggests using the same material as I have purchased to insulate my firewall, but thinner stainless steel, and no overcover for the Fiberfrax, because it says to put the Fiberfrax between the firewall and the composite. (I was planning to put the stainless steel firewall directly on the composite flange per the plans, but then overlay with Fiberfrax and very thin stainless sheet (0.003 inch) to protect the Fiberfrax. That is, the insulation on the engine side vs the cockpit side of the stainless firewall. However, I think the link might be describing installation on a full composite bulkhead, vs a flange. In my case, I think cockpit side material would compress too much between the flange and the firewall (loosing insulation effectiveness) especially since the motor mounts go on top of the firewall, compressed against the flange with four AN7 bolts. I can also get save a few pounds compared to the uninsulated kit material weight if I use .018 inch stainless steel instead of the 0.030 supplied with the kit. I called the kit manufacturer, and he confirmed the kit does not require the thicker stainless for any structural reason. But no information on fire-resistance improvement of sides and bottom of the fuselage. Guess I'm still on my own for that.
  5. langted

    Cowl Air Temperatures

    It appears you get about the same result using the "perfect gas law" Air Density = P x Ma / (Ru x T), where density is in pounds/cu ft, P = pressure in psf, Ma= Molecular weight of air (28.9), Ru is universal gas constant, (1545) and T is absolute temperature (this is ambient temperature Fahrenheit plus 460). (You have to forgive me, I work in old British units since I'm in the US. Can convert if anybody cares, but then I'd have to look stuff up) Let's assume your OAT is 70F ( 21C), and your Carbi temperature is 106F (41C), which is 20C higher. Since you only are interested in the air density change due to temperature change, you can forget most of the constants, and just make a ratio of the absolute temperature change. So, Density change = density1/density2 = (T1+460)/(T2+460) = (70+460) / (106+460) = .936 (or a 6.4% reduction) So theoretically, the 20C (36F) rise cuts air density (and engine power) by about 6%. I don't know your engine hp, but if it's around 100 hp, that's about the same as by the rule of thumb.
  6. Interesting that nobody yet has said, "don't worry about it, just build it and go fly". Wood is an interesting thought. I'll have to look into what temperature it starts to char vs Fiberglass turning to "slop". Another advantage is that if it didn't delay the fire long enough, you would die to the pleasant smell of a campfire rather than toxic resin fumes. ;)
  7. Yes, as I understand it, the underfloor is another critical area becase the flames are initially swept against that area by the cowling exhaust air. This is also often a big weakness in aluminum aircraft -- even though the SS firewall may hold, the aluminum on the belly can melt away very quickly and then the fire consumes your feet as you try to get down. Aesthetically, it's harder to protect that area, since it's visible and it has compound curves that stainless sheet is hard to form around, and it's not pretty if you try. I have located a few moderately high temperature (~1200F/649C) insulating materials that have some "formability", but these are mostly aluminum faced insulation, which limits their usefulness. (They are generally made to reflect exhaust heat from nearby exhaust parts, not made as a fire-retardant material). Still, they may slow things down a little to buy time, as Nev says. I am thinking of using the aluminum stuff on the rear inside of the cowl to try to kept the cowl intact awhile and containing the flame, and maybe a small SS deflector under the cowl outlet just to keep the flames from making direct impingement on the belly skin, if I can convince myself that it would work. (might loose a couple knots on that). I would love to find some deeply "dimpled" thin stainless sheet, as dimples tend to allow the material to take compound bends, but I don't see any suppliers. I also like the idea of standoffs for the firewall, but these would obviously still need to be sealed. I looked up those sealants-- 400F (204C) service temperature and "flash" temps as high as 2000F for one and the other at 3500F (1925C) !!!! Great stuff but also PRICEY at $200-400 US for a small tube!! Thanks for the thoughts -- keep them coming. Ted
  8. I am currently building an Arion Lightning, which has a fiberglass fuselage with a stainless steel firewall. I will be paying attention to making penetrations fire resistant (e.g. not using plastic or aluminum pass-throughs), but I am wondering about the mounting of the firewall directly against the fiberglass fuselage flange. It would seem that the heat of a fire, applied to the fiberglass via the thin stainless sheet, would quickly cause a lot of smoke and failure as the fiberglass overheats and burns. I was reading about this on Van's forum, and looking at recommendations from (I think it was Dan Horton??) who did a lot of research and favored use of a high temperature insulation (like 1/8" of fiberfrax), covered with a thin (0.002") stainless layer to protect the fiberfrax, both on the engine side of the firewall. This would seem even more critical on a fibrerglass aircraft than on a aluminum aircraft. So, I was wondering what other fiberglass aircraft use in this area, or what other fiberglass aircraft builders are doing, if anything, to enhance fire resistance of the firewall?
  9. langted


    Dave- I haven't been on the forum for awhile, but I'm glad to see you finally got the bird home. I did about 6 days of factory assist on my own lightning in October. Since then I've done a little work on it, but I've largely been sorting other things out. That includes some infrastructure on the local airport workshop I'm renting. Being an amateur mechanic, I had a lot of tools, including compressor. But, airplanes are different and I found I needed a few tools.... resin.... fiberglass cloth.... bit parts and stuff not included in the kit. Now that I'm finally getting traction on the project, it has gotten prematurely cold for the last 2 months (Winter in US) and my shop heat is not great. Sigh..... After the build assist, I was able to bring it home on a large rented landscaping trailer, so fortunately I didn't have your HUGE shipping bill or import tax (but I do have 6% sales tax.). Also, although not as cool or fast as your turbine, I opted for the Titan 340 with fixed pitch prop which is cheaper. I'm planning to use a Prince propeller -- they are light weight, seem to have good performance, good reported factory support, they are reasonably priced, and I ride my bicycle past the factory every few days in the summer (Maybe I'll just strap it on back of my bike!) My plan is to get everything fitted including instruments, then take it back to Shelbyville for paint, reassembly, and test flights. Then fly it back home. Schedule ??? Who can say at this point. Hoping for next Fall. (I know - naive). Do keep us posted on your project -- much more interesting than mine. Ted
  10. langted


    Repeating Dave's comment, the lightning was not originally designed within LSA restrictions, but rather it was slowed down to meet LSA restrictions. (This is a good time to correct a typo in my 6-22-18 post: most existing lightnings in the US are E-AB not E-LSA). So as Dave indicated, its an incremental, rather than a big a push to the design. Personally, I'm not one to take a lot of risk and I like bigger margins. For those reasons, I am exploring using aluminum fuel tanks and a BRS parachute which are available on the lightning. I also like mechanical simplicity and less vibration for which Dave's turboprop should excel. Although this time around, my build will be too soon to take advantage of Dave's turboprop, I still hope to get advantage of any modifications that might improve Vne margin. With an expected cruise of "only" about 155knts, my build will be "OK" in that regard, but more margin is still worth a little expense. So I'm keenly interested in Dave's progress, look forward to more testing of the desgin at higher speeds, and look forward to a (hopefully) small retrofit to my airframe as a real benefit.
  11. langted


    So... you're saying our IQ is well over 200?
  12. langted


    It's amazing how fast this aircraft goes together! I was very happy with the building environment, although sorry I was only able to be there on day one and wasn't able to connect with Dave. Can't wait for mine to start. Of course Nick just had to capture my "bald spot" while I there.....
  13. OK....will report back as the kit progresses. By the way, I did take a test flight in the factory demonstrator with a Superior O-320. It flew very nicely (on "rails" as they say), but since it was the only factory demonstrator, Nick (Arion owner) was reluctant to let me land it. This resulted in a lot more questions to other lightning owners, which eventually satisfied me that landing qualities are fine. However, I expect to do thorough transition training since I am coming from a 115 hp Citabria 7ECA.
  14. langted


    Well after further review, I just started the process to buy a lightning XS kit. With respect to any concern over propensity for lightnings to be damaged in accidents, a previous post notes that the NTSB in the US has an accessible online database that details all the reported general aviation damage accidents. Using data from the NTSB, the FAA compiled a report in 2014 (called a "Continued Operational Safety (COS) Report") that summarizes (only) light sport accidents in the US from 2004 to 2014 from all manufacturers (I imagine a lot of forum members have seen this). With respect to the Arion Lightning LSA, its accident rate was not the lowest, but slightly lower than the average (which is good, considering its performance). However, the since the report only includes factory assembled LSAs, it does not include amateur built LSAs or experimentals in either the reported accidents statistics or the number flying. So I made a similar tabulation for the lightning using the NTSB database for all lightnings in the same period, LSAs and the rest (most are E-LSA). The result was essentially the same, i.e. still a little less than the average accident rate of the factory built LSAs from all manufacturers. The accident reports included damage incidents from before the lightning tail improvement, so if extracted from the data, that might make matters even better. (Note that this was just my personal review, not error checked...my engineering disclaimer). In the end, I was satisfied. With respect to landing difficulty, this seems to not be big deal, but it is a performance oriented airplane with higher than typical wing loading. As to shorter fields, one guy I contacted in Indiana (who has serial number 12 and loves it) reportedly flies from a 610 meter grass strip with 25 meter trees right at each end, and the original tail. This isn't a STOL strip, but a lot tighter than I will need. So, after test flying it, in my book, the lightning performance and handling is excellent, price reasonable, looks great, build time is minimal, and its safety record is on par with others. A lot of positives there, and good enough for me.
  15. To finish off this string.... After a lot of research, talking to owners, forum feedback, a decision spreadsheet, etc, etc.... The winner is Arion Lightning. I am sending in my deposit in the morning mail. Not sure where I'll be in the que, but probably not too far behind Dave's. Choosing between these airplanes was really tough, the hardest decision I've ever made, but I think I'll be happy. Just too bad Dave's turbo won't be ready. Thanks for comments.