OpenTrainer: New crowd-sourced open-source two-seat primary training sailplane

Discussion in 'Soaring' started by BoKu, Jun 15, 2018.

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  1. Jun 20, 2018 #81

    pictsidhe

    pictsidhe

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    A double-goat could attract a lot of interest.
     
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  2. Jun 20, 2018 #82

    ypsilon

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    The obvious choice for you then is to go electric. Look at the Electro-Swift. The drive was largely developed by Manfred Ruhmer based on readily available components. It gets about 1500m altitude out of one full charge. So unless your glider is stone-shaped the 3 Mile radius won't be a problem.
    Electric propulsion for Sailplanes is really lifting of in Europe. FES seems to be successful, but only the ultralights can use it to self-launch (e.g. Alisport Silent 2, Mini Lak). Others still use classical retractable props (like GP). The Streifeneders even built an electric drive for the 50 year old H201b Libelle, which will be available as a product by the end of the year.

    There are many components available, that can be used in an homebuilt environment (e.g. Look at Darek Lewek's Geko project).
     
  3. Jun 20, 2018 #83

    Pops

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    Great.
     
  4. Jun 20, 2018 #84

    billyvray

    billyvray

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    similar vein:
    Just for the fun of it I recently took an old cheap beach boogieboard that was my son's and glassed it. After using it as a snow sled this winter the fabric covering was done for. I covered with two layers of 5oz biax on each side. I did the absolute minimum of finishing by simply painting with white latex house trim paint (Glidden I think). I did not do the final epoxy skim coat because I ran out of epoxy!
    So, yes it has pinholes, but the latex has surprised me with it's tough finish. A trip to the beach with riding it every day and no wear to be seen ( except for the black trim part which was done with Sharpie!).

    I'd think with the epoxy skim and then latex a cheap finish could be accomplished.

    IMG_4478.JPG




     
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  5. Jun 20, 2018 #85

    BJC

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    Bob:

    That is a noble goal. I wish you success.

    A few questions, if they don’t generate thread drift. My questions are from the point of view of someone who never has flown a glider, but has long had an interest in them.

    Is the lack of a new trainer a significant obstacle to having more glider pilots? A near-by airpark has lots of gliders, both single seat and two seat. It is rare for any of them to fly. We are located in the central Florida convergence, and soaring conditions generally are good.

    What are the other significant obstacles?

    Would a Blanik with new wings meet your goals?

    If the focus is club training, is assembly time important, or are most club-owned trainers hangared assembled?

    Is the cost of an aero tow really an impediment for someone who wants to learn to fly? I understand that cheaper is better, but people spend lots of money on their hobbies.

    For me, there is too much hassle involved to operate a glider, although a reasonably priced motor glider with a wingspan of no more than 38 feet would interest me.

    If this is out of the intended scope of your questions, please say so, and we will drop it.

    Thanks.


    BJC
     
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  6. Jun 20, 2018 #86

    Hot Wings

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    IMHO you just partially answered your own question. Solo operation is just too hard, or impossible. Solo rigging is possible but then how do you get the thing air-born? I know there are plenty of reasons why a pilot operated winch is considered a poor idea but if safe one could be developed it might go a long way toward making gliders less of a "hassle".

    I think a safe solo operated winch could be developed and might be a better open source/funded project than a new glider?
     
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  7. Jun 20, 2018 #87

    BBerson

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    Never flown a glider? Ouch!

    I think a whole new sport is needed. Perhaps slalom gliding down a mountain course.:)
    Gliders are boring because they can never descend below pattern altitude usually. And just doing circles at altitude is boring.
     
  8. Jun 20, 2018 #88

    BJC

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    I had a classmate who was a CFI - glider who worked at his fathers flight school. He went home on the weekends to instruct, and invited me to join him. He said that all I would need to pay for to get a glider rating was the tows. Back then, the choice was between eating or flying, so no glider time came out of his offer.

    I do have a few minutes in a Citabria glider.


    BJC
     
  9. Jun 20, 2018 #89

    Toobuilder

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    I have a bit of glider time which was pointed toward an add on to my PPL. Started with a "tourist ride" in Hawaii in a SGS 2-32. The pilot was an instructor and the "ride" quickly turned into a "lesson". Since I was in Hawaii for a month on business, I returned a few more times to take some additional lessons in a 2-33. The cost seemed reasonable and the availability was no problem. I always intended to finish the rating but never have. Someday.

    With all that said, I have to echo BJC's sentiments/questions. I fly near (and often directly over) some of the "hotbeds" of soaring (Tehachapi, Cal City, Crystal Aire), and I sure see a LOT of sailplanes sitting in the dirt without a towplane in sight. As I said, I've looked into finishing up the training, but I sure don't sense a compelling urge to do so before the equipment dries up - seems like there is PLENTY of capacity. Is there "actually" a need for a new ship?
     
  10. Jun 20, 2018 #90

    Pops

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    I started out working in the ground crew in a glider club with about 50 members. Had two 2-33's and two I-26's and 3 or 4 private owned gliders with a Piper Super Cub tow airplane. My first flight instruction was in the I-33 and the Super Cub as payment for working weekends in the ground crew. My powered flight instructor was also the sailplane instructor and owned a homebuilt Cherokee Sailplane that he built. We would go to the sailplane meets at New Castle, VA and at Linville, NC. I would help in the ground crews. Had lots of fun. Latter I bought a I-26. My other time in a sailplane was when I ridge soared a 1959 Cessna 172 from Selinsgrove,PA to Morgantown, WV on a very windy day.

    Never boring.
     
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  11. Jun 20, 2018 #91

    autoreply

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    Absolutely. But most trainers, at least here, are kept assembled most of the time. Notably the II is a pretty good trainer. (Seen too many III's spin into the ground and assembling a I once was more than enough).
    While personal preferences certainly have their part, most clubs do away with their 13's because the 21's are more affordable to operate and more tolerant to abuse. 2nd hand pricing reflects that.

    I fail to see why the weight of the 21 is a drawback at all? Most launch equipment is laid out for heavier gliders anyway.
    While I have more outlandings than I'd like to admit (dozens, including the Alps), it's not the safety or challenge I'm concerned about so much.

    To me it's more about how you're planning your leisure time. Going XC without an engine means you have to arrange volunteers to pick you up as well as reserve the evening and night for a long retrieve. With an engine it turns into a leisure activity like flying a powered aircraft or sailing where you can count on being at home at hour X.


    @ Bob,

    I don't understand what problem you're trying to solve. Compared to what's on the market (ASK21), I fail to see how you're significantly going to improve a trainer?

    If the big goal is to reduce the cost of soaring training, IMHO, that's in making launches affordable. A two-seater with a FES-like system in the nose that allows for self-launching could revolutionise soaring.
     
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  12. Jun 21, 2018 #92

    Victor Bravo

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    Most soaring clubs and small commercial operations in the USA do not have the volume of active members or numbers of flight operations as they do in Europe. Which means that the cost of an "expensive" trainer like the AS-K21 cannot be amortized over anywhere near as short of a period of time as they can elsewhere. So in order to purchase even a used AS-K21, a small club or small flight school is taking a very large leap of faith over a much longer period of time. They more often don't have the money to even think about it.

    So the concept of a "super cheap" two seat training glider is perhaps a lot more relevant in areas that do not have clubs with hundreds of members or flight schools with hundreds of students. This may seem strange to Europeans, everybody loves to think of America as being rich and corpulent and spoiled. Where soaring is concerned, and especially soaring clubs, this is the opposite of the truth.

    As a sad but factual example, the largest "flight school" for soaring in the 100 mile radius surrounding Los Angeles does not have a large enough number of consistent "regular" private glider students to justify purchasing new or upscale used training gliders. The only reason this major soaring center can operate profitably is because they also have a long-standing contract for providing sailplane training for the US Air Force test pilot school students (USAF Test Pilot School / Edwards AFB is only 20 miles away). If this Air Force contract were to end tomorrow, this soaring school would likely have to cease operations within a few months.

    Remember, this is the largest of the three or four soaring schools within 100 miles of America's second largest city.

    There is another somewhat profitable soaring school in this geographical area that does not have an Air Force contract. They happen to be 30 minutes closer to Los Angeles, which helps a lot,a nd they also have some sort of contract with the Wounded Warrior project, which augments their private student income.

    Bob K knows all of this very well, and has spent a lot of time at these soaring sites as have I. So I must agree with him that there is definitely a market or niche for a more inexpensive low performance training glider. All other factors being equal, the AS-K21 is certainly more efficient and cost effective as a trainer, as Autoreply and others point out. But all the factors are not anywhere near equal here, which is why the ancient dinosaur 2-33 and the other cheap solutions being discussed in this thread have merit.
     
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  13. Jun 21, 2018 #93

    Toobuilder

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    ...but the question remains, is there a capacity issue? It sounds like a resounding "no", so what does adding capacity (in the form of a new machine) do to help the sport?
     
  14. Jun 21, 2018 #94

    pictsidhe

    pictsidhe

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    Well I'm struggling to find affordable lessons.
     
  15. Jun 21, 2018 #95

    proppastie

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    I assume you mean glider, although affordable aircraft lessons can be a struggle too. It is easier to find aircraft lessons and after you have your PPL the glider rating is faster easier less money. I am thinking hang glider lessons might be more appropriate for your design though.......very much different. I do not know how good PPL or glider rating will be for a UL
     
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  16. Jun 21, 2018 #96

    BBerson

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    Yeah, the commercial hang glider operators likely have the lowest cost tow.
    It's unfortunate the Light Sport rule didn't result in new two seat trainers. (none, as far as I know)
     
  17. Jun 21, 2018 #97

    ElEsido

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    Hi all

    I don’t know about the financial situation of clubs in the US. But from a European perspective it’s the costs of the tug plane that are the most significant factor on the way to the license. From this perspective developing a new tug plane that’s cheap top operate might be a goal that is as worthwhile as developing a new glider. Take a look at the fs35 of the Akaflieg Stuttgart: http://www.uni-stuttgart.de/akaflieg/projekte/die-flugzeuge/fs35-das-aktuelle-projekt/. An aircraft that could be built by clubs might be attractive.

    An idea that sounds so crazy that it should be tried: A retired engineer shared with me that the Swiss airforce used a type of steam boosters to assist the takeoff of airplanes. A pressure vessel with water and an integrated electric heater produced steam and the pressure that was released through a nozzle. The thrust was controllable and could be adjusted, shut off and re-started until all the pressure was gone. The empty vessel apparently didn’t weight too much. Put that in a glider and use it for take-off, and add a FES (front electric sustainer) for the occasional climb during airwork to increase the students’ practice time and you can fly cheaply without the need for a ground crew. (Use an FES and not a Pylon mounted prop behind the cockpit since the latter takes too much attention to operate and is a formidable airbrake when it’s stuck.)

    Best
    ElEsido
     
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  18. Jun 21, 2018 #98

    ypsilon

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    How much more affordable, though? I spend maybe an extra day per year on a wooden glider relative to a plastic ship. Considering that the 13 is about 15-20K€ and the 21 is about 50-70k€ that extra day is considered very expensive, or it takes a long time before the 21 is more affordable. My thinking is, that the are less and less "wood-bugs" in the clubs, and if you don't have anybody with the knowledge and skills the plastic is just the safer bet.


    Inertia, around any axis you choose to rotate about. I found that stundents prefer light, nimble and slow. Especially when landing. YMMV.

    We're not in disagreement. The point I made is that by far most (fatal) outlanding accidents happen with Turbos or SL-Ships, because pilots are overwhelmed operating the engine and flying under critical conditions at the same time. If something goes wrong (e.g. engine doesn't start for whatever reason), many don't have the capacity to deal with this rather dense situation properly.
    Outlanding is more fun when you are younger and flying in a flying "family". Retrieval was more like a welcome reason for another party (plus you knew in advance who pays for the beer!)
    Sure when you get older this doesn't work the same way anymore, it surely doesn't for me, so yes an engine makes sense, but I think that danger of the (by aviation standards) unreliable two-stroke Turbos are a dangerous answer for a comfort problem. FES, on the other hand would be a good solution, but I'm not sure if it is possible to Self-Launch a two-seater with such a little prop.
     
  19. Jun 21, 2018 #99

    choppergirl

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    I think you could build 5 to 10 towable old skool two seat primary gliders, for the cost of just one composite two seat sailplane... a two seat primary towable glider like this one.

    If I started a flying club, that is all the kids would build, two seat primary gliders. All the time. Several flying while yet another is in the jigs being built. Stick to just one plane design, not sixty and half a dozen other !@#$ all in the hanger.

    Make the first one. Once we got the first one done and all the jigs and methods figured out, then churn out a dozen over time; let them crack them up; fix them, fly them again. Get too beat up, sell them off to club members to fix on their own time.

    It would be the primary way my Flying Circus would be doing things right, where EAA was floundering and doing things wrong. :-D

    Want to learn to fly? Only 12 years old? 60 years old? No money? Lots of money? Don't matter. Get in...! Put on these goggles. Ride in the front.

    If I go to Fly ins, they have signs all over the planes that say "Do not touch". :-( Just to counter, my plane signs will read "Go ahead, touch me!" :)

    Have a day every month, where anybody from the public can show up and get a ride in the front seat. Anyone with any interest or aptitude or knowledge whatsoever. And after some crash course bare basic pep talk, take the controls.

    And you're not doing this already, why?
     
    Last edited: Jun 21, 2018
  20. Jun 22, 2018 #100

    Victor Bravo

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    Congratulations on re-identifying how gliding was done in Europe 80+ years ago. Worked great when the government subsidized 80% of it and paid for everything, and when the average home in Europe did not have a flushing toilet, refrigerator, a car, or a telephone.

    SOME of the main components of this idea are still 100% valid, but some are not.

    A majority of people today have full time jobs, which would pretty much prevent them from putting in most of the "sweat equity" to be building and repairing gliders, which was an integral part of how it worked back then.

    The open primary glider is not conducive to dual instruction. It is cold, windy, and would be downright frightening to a lot of people sitting out there in the open a mile above the ground with nothing around them.

    The low performance and high sink rate of the primary glider reduces the amount of instruction that can be provided for every takeoff/fly/land "cycle".They are only soarable in moderate lift, the SGS 2-33 performs like a Nimbus 3 compared to an open primary.
     

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