# Issues and Solutions for kit- and plans-based sailplanes and motorgliders

Discussion in 'Soaring' started by TerryM76, Sep 3, 2019.

1. Sep 3, 2019

### TerryM76

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Moderator Note: I forked this discussion off to its own thread, as it's really no longer related to the ESA Western Workshop thread where it began. - Topaz

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I regret not being able to attend last year but I am glad that 2018 is in my rear-view mirror now.

Obviously a barrier to entry is not due to low cost gliders nowadays, as Doug Fronious and others pointed out and I am sure there are plenty types waiting to be resurrected to see the light of day again. The certificated gliders will need the attention of an A&P/IA every year but maintenance can be supervised by an A&P or performed if its beyond the skill of an owner. Not sure if that is a barrier for interested people.

My own personal barrier right now is having the resource of time and maybe that is keeping a few people from getting engaged with this activity. I am currently trying to line up the necessary components for retiring in about 6 years but if I keep waiting to get back into gliding it will just remain an elusive dream.

So, why don't you guys all move to the Phoenix area in about 5 years, I'll do your Condition/Annuals and you pay for the parts.....and give me the keys to your glider after I sign the logbooks?

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2. Sep 3, 2019

### Topaz

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I hear you. I'm going to feel the same way very much about 2019.

Oh, sure, of cour.... wait, whaaaat???

3. Sep 3, 2019

### TerryM76

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Just borrowing the keys........ And if I break it I'll fix it.

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4. Sep 3, 2019

### Victor Bravo

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So Terry am I reading your comment correctly... are you saying that Doug does NOT think that an inexpensive entry level DIY glider would attract more people to soaring?

A decent flyable 1-26 is about 9-10K and up these days. An HP-14 or 18 is higher than that. There's no such thing as a $4000 L-Spatz or AS-K18 that you'd actually want to fly. No 1-34's for a few grand. AFAIK the only really cheap gliders are ones that have some significant work to do, or a risk of that work becoming needed (balsa cored Phoebus, wooden Ka-6 etc.) Someone who wants an enclosed "sailplane" style glider on a low budget, what are they able to come up with at this point? 5. Sep 3, 2019 ### erkki67 ### erkki67 #### Well-Known Member Joined: Feb 18, 2010 Messages: 1,757 Likes Received: 190 Location: Romont / Fribourg / Switzerland The RF2 was the prototype of the production RF3. Join the club at: http://club-fournier.org/ Translate if required by google translator. TerryM76 likes this. 6. Sep 3, 2019 ### PiperCruisin ### PiperCruisin #### Well-Known Member Joined: Jan 18, 2017 Messages: 142 Likes Received: 65 Location: Idaho It was fun to meet some of the HBAers and prodding Topaz to keep working on his motor glider...maybe we need our own convention to hash out some designs. Generally speaking, the group was looking a bit long in the tooth. It needs new blood and there was some good discussion on that. A combination of cost and availability of tows is a big issue. Medium performance motor gliders could be an answer, but it is hard to convince a group of purists. Xenos has great value (hats off to Pete Buck), but hard to store in a hanger (needs to fold or easily removable tips). Apparently it is possible to get a Pipistrel Sinus kit in the US, but the high wing and spar create space and thermaling visibility challenges. TerryM76, Topaz and BoKu like this. 7. Sep 3, 2019 ### TerryM76 ### TerryM76 #### Well-Known MemberHBA Supporter Joined: Sep 8, 2012 Messages: 535 Likes Received: 198 Location: Tempe, AZ If I understood Doug correctly, he was comparing current kit gliders to certificated "used" gliders and I don't believe that he was not suggesting that an inexpensive DIY glider would be beneficial in attracting more people. I know those are apples to oranges comparisons and I haven't done any "shopping" lately to understand the current market for used, low-medium performance gliders. The point as I understood it was that there are other barriers beyond cost of glider. I tend to hear what I want to hear in meetings and zone out during other times.....I was zoning for about half of the panel meeting so I may have missed some key points. "Someone who wants an enclosed "sailplane" style glider on a low budget, what are they able to come up with at this point?" ...........If there was a solution given, I missed it. Maybe Topaz or PiperCruisin can help with that. 8. Sep 3, 2019 ### Topaz ### Topaz #### Super ModeratorStaff Member Joined: Jul 30, 2005 Messages: 13,964 Likes Received: 5,588 Location: Orange County, California If I understood Doug correctly, I agree with Terry: He was saying that used gliders and current kit gliders (meaning, essentially, Bob's HP-24) are essentially the same thing, which means the primary competition for a notional new kit glider of that ilk is the currently-saturated used-glider market. He was suggesting (as were several others) that the kit market focus on niches that are not well-served by the used-glider market. That implicitly means that we need to get away from the emphasis on pure performance, and focus on other attributes. Motorgliders are one, micro-lift gliders are another, extremely portable folding "real gliders" are a third. Simple: Cruise Wings and Wheels for a very few months. Some good deal is going to come up. The used market will dry up eventually but, right now, if you want a "conventional" enclosed sailplane at a reasonable price compared to a new one, the used market is where you go. Because, to the best of my knowledge, there are exactly three "kit" gliders out there: • Bob K's HP-24 • Sandlin's GOAT and BUG gliders, and • The ULF-1 That's it. There has been some talk about someone bringing the SGS 1-26 kit back on the market, and other talk about someone offering a kit for the RF-4, but the former talk stopped some years ago and we heard on the panel that the RF-4 project has died out as the details of the design are considered impractical for a kit. The JT-10 and Mark Calder's Robin have been working up for a number of years, but the Robin project seems to have stalled out just short of first flight, and I don't think the JT-10 is actually even in build yet, is it? There's my project, but it's not even as far along as the JT-10 and, even if I were to offer it commercially, it'd be as a plans-only thing, with no true "kit" involved at all. I don't want to go into the kit business. There's little future in it unless you're Dick VanGrunsven. 9. Sep 3, 2019 ### Hot Wings ### Hot Wings #### Well-Known MemberHBA Supporter Joined: Nov 14, 2009 Messages: 6,635 Likes Received: 2,522 Location: Rocky Mountains As someone that is still trying to break into soaring I'd have to agree. It's not the cost of the hardware, it's the availability of infrastructure and/or the "right" hardware. I've got a cheap glider that would take me a week of concentrated fiddling to get a condition inspection signed off but it sets in storage. Why? Because I still need a glider rating, and the infrastructure to get it in the air. The glider rating is not a real problem. For me it still involves a 212 mile drive to the nearest field. That is a solvable problem. BUT: With the rating in hand I still need the infrastructure of the field and club to get my glider in the air. Even if the field was local that still means coordinating with others schedules to get the tow plane/winch operational. Then there is the problem of out landing. That requires the assistance of others who may or may not be available without setting aside a chunk of their free time. Solution? Simple! Inexpensive, self-launch, trailer-able and easy to solo assemble gliders. Problems: Old school glider pilots don't like power. It's not "pure" and the existing self-launch sailplanes are expensive. Such a glider doesn't exist - yet. Topaz is on the right track. I've been sketching and calculating my version of the solution to this problem for several years. All of the above is why I jumped on the AV-36 opportunity. It isn't exactly my version of what I, or most conventional sailplane pilots, think would be ideal. It's wood. It's a flying wing. It has to be built from plans. All of the powered versions have been owner modified, there is no standard power package. But it does fill many of the my perceived needs. Being a flying wing, to me, is just a bonus. None of the 3 gliders Topaz mentioned are going to fill the niche that the AV-36 with power, or Topaz's design will. This is were we need to concentrate our time and energy if we want to significantly lower the soaring entry barrier. gtae07, GeeBee3 and TerryM76 like this. 10. Sep 3, 2019 ### BJC ### BJC #### Well-Known MemberHBA Supporter Joined: Oct 7, 2013 Messages: 10,221 Likes Received: 6,953 Location: 97FL, Florida, USA Van’s personal motor glider project has been at a stand still for some time. It never was intended to be a kit, but would have been a reasonable benchmark. BJC Topaz likes this. 11. Sep 3, 2019 ### Topaz ### Topaz #### Super ModeratorStaff Member Joined: Jul 30, 2005 Messages: 13,964 Likes Received: 5,588 Location: Orange County, California At both this year's ESA workshop and last year's, I saw a broad consensus that self-launching gliders and motorgliders are "the future" of soaring, for exactly all the reasons you mention. Sure, the purists grumbled about it, but even they acknowledged, grudgingly, that soaring needs to evolve in these directions if it's going to survive. The club model isn't taking off to the degree it has in Europe, and the FBO model here isn't a broad solution, either, because of the difficulty of creating a viable long-term business around it for soaring. An additional problem, seemingly across the entire soaring community, is the obsession with absolutely "top" performance. The ESA group is more broad-minded than most I've encountered but, even there, mention that your glider or motorglider design will have an L/D of 30:1 or so, and the usual response is something along the lines of, "Oh. That's... nice." The mentality seems to be such that, if a glider isn't 40:1 or better, it's not worth flying "unless that's all you can afford," said in a tone of pity and sympathy for your financial difficulties. At the ESA convention I heard someone say, out loud, regarding a motorglider concept someone mentioned (not mine) that, "Well, that's not even as good as a 1-26 or 1-34, so why bother?" Lower-performance gliders such as the GOAT, BUG, or ULF-1 are met with a "how... quaint" attitude. This impacts new developments by nearly requiring new designs to make 40:1 or better performance. If they don't meet this "standard," it seems as if they will be ignored or even actively derided by the larger soaring community. Yet that kind of performance is explicitly what makes sailplanes so expensive. Excepting the Robin, JT-10, my own effort, and now you with motorizing the basic AV-36 design, I don't see anyone really working in the moderate-performance motorglider space, at least in the USA. In a sense, I hope so. I'm just doing my project for me, and am deliberately "dumbing down" the design as a first-iteration, to be refined later. But I don't have any plans to kit any of my designs either, and at best might offer plans at some small price which would cover the labor cost of a builder's newsletter. I would love to see more efforts in this niche. My target is the AS-K14, in terms of concept, and I think there's a lot of room there for other ideas and developments. We just need to get people doing it, finishing them, and get it through the head of the soaring community at large that even if one doesn't have a Ferrari, it's still worth your time to drive for fun. As always, YMMV. Last edited: Sep 3, 2019 12. Sep 3, 2019 ### Topaz ### Topaz #### Super ModeratorStaff Member Joined: Jul 30, 2005 Messages: 13,964 Likes Received: 5,588 Location: Orange County, California At a standstill for decades, as far as I know. I wish he'd finish and fly it, if for no other reason than helping the visibility of the E-AB soaring niche. Van flying something in that niche, even if he never puts it on the market, would get a lot of coverage. 13. Sep 3, 2019 ### Hot Wings ### Hot Wings #### Well-Known MemberHBA Supporter Joined: Nov 14, 2009 Messages: 6,635 Likes Received: 2,522 Location: Rocky Mountains Why bother? "Because I'll be in the air in less than an hour from my door step any time of the day, any day of the week, while you have to wait for the weekend and the tow pilot/plane/winch to be available. Any my paltry 30/1* glide ratio is actually better than the 1-26 and as good as a dinged up 1-34." The Topaz version of this solution should be even better. I still wish you had gone down the asymmetrical pusher path...... *Given the slab sided AV-36 has been flight tested at 24/1 30/1 for a cleaned up version seems reasonable? Not too bad for a FW. pictsidhe, gtae07 and Topaz like this. 14. Sep 3, 2019 ### Topaz ### Topaz #### Super ModeratorStaff Member Joined: Jul 30, 2005 Messages: 13,964 Likes Received: 5,588 Location: Orange County, California And that, of course, is the "right" answer, and one of the two big reasons I'm doing my own instead of buying a used glider and flying from a regular gliderport. Unfortunately, that answer meets a veritable thicket of "yes, but..." minimization-of-issues answers when you're talking to many conventional soaring pilots, in my experience. After the ESA Workshop, I'm actively working on wingspan trades, so I seem to have caught some of the "performance disease" myself. My project's span is currently 35' (10.7 m), because that's the maximum span that can reasonably be built in a "standard" garage, using sailplane-style stub-spar wing joins, two removable panels, and a 7'-wide center section fixed to the fuselage. With it, I get soaring performance somewhere in-between a 1-26 and a 1-34, which really means it's about like a "real-world" 1-34. Options for longer span include: • A three-panel wing, with two 14' outer panels and a 16' span removable center panel (44'/13.4m). The downside here is that two complete set of control breaks for the wing would be needed - one from the center panel to the fuselage, and a second from the center panel to the outer panels. It also places some pretty severe limits on the positioning of the wing on the fuselage - for all practical purposes, you're limited to shoulder- and high-wing designs. • Adding removable outer "tips" to the original 35' span setup, giving an arbitrary span up to 65' (19.8m). This option, while it has more wing joints, eliminates the need for a second set of control breaks that an all-removable three-panel wing would require. A "traditional" 15m span would have a 7' fixed center section, two removable 14' span panels (with 2' stub spars), and two removable "tips" of just over 7' span each. Sonja Englert is using more-or-less this setup on her Caro 1, and flies with the outer tips removed for powered-cross-country, which is an interesting option. This is a brief diversion from the existing design. I'll probably retain the original wing and heed my own counsel about absolute performance. I still sketch two-seat designs, and one of the very strong candidates for that is an asymmetric pusher. Not quite like that sketch, except if looking directly from above. I'm really fascinated by the trailerability/build-space/performance trade-off. Would I like a true 30:1 soaring capability, or even 35:1? Sure. I just don't see how that is really practical to build in a standard garage without breaking the wing into a bazillion pieces. A "standard" single-car garage is theoretically 20' long inside. Most modern ones are exactly that. Some, however (and this includes mine), are actually 18' long inside and, for a real-world build with clearance to the door and back wall, that means the maximum realistic part length is 16'. A 14' wing panel, with a 2' stub-spar for a sailplane-style wing joint, is 16' long, so that's the limitation. Last edited: Sep 3, 2019 15. Sep 3, 2019 ### BJC ### BJC #### Well-Known MemberHBA Supporter Joined: Oct 7, 2013 Messages: 10,221 Likes Received: 6,953 Location: 97FL, Florida, USA Not trying to change the subject, but there is a parallel in the aerobatic world. Look at the recent World Aerobatic Championship. https://wac2019.fr/en/results/ The top positions once were homebuilt airplanes. Now, only one homebuilt participated. Almost all the top participants flew the factory built Extra 330, except for Rob Holland in the MX. The Extra, with all the neat options, is close to$500,000.

But wait; Walter had a newer version on display at Oshkosh, so used 330’s soon will be available.

When a competitive sport starts drawing sponsorships, the technology rapidly advances, the cost goes up, and the opportunity to participation at the top level goes down. Find a way to put the fun back into it, or the number of participants will continue to fall.

There are lots of affordable fun aerobatic aircraft. A new design would be welcomed, but isn’t necessary. Is the same true for soaring?

BJC

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16. Sep 3, 2019

### Topaz

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I suspect the situation is highly parallel, in that both forms of aviation have become competition-obsessed, IMHO. I freely admit that I don't see but a small slice of the larger soaring community, but my impression is that, if you're not always trying for a "personal best," actively participating in the OLC (On-Line Contest), or practicing/participating in actual in-person competitions, you're kind of a "redheaded stepchild" in the sport. Doing it just for fun, with no "declared goal" or "I want to break my cross-country distance record," seems to get you a consistent and polite, "Oh. That's... nice."

Is the situation similar for aerobatics? Are "just for fun" pilots seen somewhat as "lesser animals," so to speak?

Same situation in soaring. For actual competition, I think it's unavoidable, as artificially-handicapped "low cost" classes are given the polite, "sure, we'll let them do their little competition before the real flying starts" treatment as well. That, along with the fact that "low cost" competition categories end up being anything but "low cost" by any standard except comparison to the full-blown racing ships.

Wow. I'm remarkably bitter today. Ugh.

I think so. I earlier alluded to a couple of efforts to revive the SGS 1-26 and the Fourier RF-4, particularly as kit-built aircraft. Even though the 1-26 was originally designed to be a kit, and quite a lot of them were built that way, every time I hear the topic mentioned, I invariably hear responses along the lines of, "Well, yeah, but it's so low performance that you're better off getting a used 'X', or "Yeah, but it's only 23:1, so why bother?" A 1-26 is a blast to fly, a little "fighter" of a sailplane, and fully capable of winning all three FAI Diamond badges in the hands of a good pilot. But apparently it's "not good enough for 'real' flying" anymore. Every time discussion of a new-design glider comes up, it invariably ends up a 15m all-molded-composite ship, that would price out at 60-70% of the list of a new competition ship - or, more succinctly, the same cost as a used example of that competition ship. So the conversation dies.

For me, I'm in a unique position in that I'm not shooting for serial production or kit-sales, so I can do whatever I want. But that also means that I'm not the guy who's going to solve the problem with the larger world of soaring, either.

How do we change segments of aviation that have become obsessed and exclusive towards competition, to again embrace the person who doesn't want to compete but rather just have fun?

Last edited: Sep 3, 2019
17. Sep 3, 2019

### Jay Kempf

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40:1 is doable but it is going to be about the same complexity and cost as the HP24. The HP 24 wing and tail molds could be used to move towards a motorglider. If being developed from scratch a real motorglider would be a better and more useful solution than a self launcher. Retractable motors are marginal and have some safety modes that are tricky for the beginner. Low and in trouble is no way to find out about how hard it is to deploy, start and fly away with a low powered and draggy motor installation. Course I am partial to a folding twin boom pusher. A 15 meter existing wing would be a good start. An existing canopy and front fuselage molds would be a good start. If you put 3 meters of center section or there about in the middle of a 15 meter wing you have an 18 meter dual place. 3 meters is too big to trailer so compromise on 2 meters to get a 17 meter dual place. Make it a high or mid wing with retractable mains into the booms with an option for a nose wheel for those so inclined and you have a pretty solid offering for the masses. But somehow the cost has to come down. There are a bunch of 600-850 cc dry sump engines water cooled motors out there for cheap, even OTS turbos, so it doesn't have to be marginal.

18. Sep 3, 2019

### TFF

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In the car world, the Import Drag Racing developed without the traditional Hot Rod drag racing help. It was reinventing the wheel somewhat, but there was very little crossover until now, and its more of the turbo stuff crossing into the regular Hot Rod than the other way. It happened separately out of necessity. Competition gliders are the Indy cars of gliding. Everyone is talking of wanting the SCCA MGB of gliders. For it to go anywhere, someone will have to design an motor glider airplane where 100-200 example will be made in 10-15 years for it to work. Its has to be a separate movement that may have some spill over to the Comp stuff. The Comp stuff will go on because its a personality test. Its not about having a play airplane, its about trying to win the Olympics. If you are a Comp guy wanting a cheap Comp glider, you are not in this club. The Club is simple gliders that can do glider things like work lift. Its not about great working lift; the aircraft has to be too good for that. It just works lift. Spec better than a I-26 is killing the concept. Looking for a Cessna 172 of gliders; in car terms you are looking for a Miata; its not about buying a Corvette because you can't afford the Ferrari. There will have to be a design that is so good people across the whole homebuilding community want to build it. It has to be fun to fly, not scary to build, and not use anything exotic.

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19. Sep 3, 2019

### BoKu

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I'll read this thread at length when I get a chance. But for now, let me put this in:

The molded exterior of a composite sailplane represents a relatively small percentage of the total cost. And the cost per unit area and per unit mass of a female molded shape is compelling. So I firmly believe that going all rugged individualist and trying to discover some oddly as-yet-undiscovered method of field-fabricating soaring shapes from commercially-available raw materials is at best a false economy.

The entire point of the industrial revolution is that economies of scale is where to look for cost reduction. Optimize ruthlessly. Pool your capital, invest in the means of production. Roll up your sleeves and get **** done.

Case in point: Right now I'm conspiring with a friend to make a 13.5m/15m glider with the HP-24 tooling. Fits in a trailer with a foldable tongue so the overall length of the rig is 25'. No flaps, and retractable gear is optional. I could get the kit price down to like $15k if I was certain I'd sell a hundred units. I could get it down to less than$10k if I knew I'd sell 500. But the hard part is that certainty.

Could I make a \$3000 glider? Sure. But it probably wouldn't be one worth flying more than a few times. And there's already plenty of Monerais in that particular niche.

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20. Sep 4, 2019

### Topaz

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Despite some apparent reports of some reliability issues (hearsay) with FES, the self-launch soaring community is rapidly moving away from gasoline-powered self-launchers to electrics. Some have the traditional retractable mast aft of the cockpit, but now there's an electric motor on top, rather than a Rotax. It's remarkable how fast this transition is happening.

Doesn't really help with a touring motorglider, that needs some range for powered cross-country, though. Not yet anyway. Which is why there's a gas engine in the nose of my project. I'd go to electric if the range was there, for a reasonable price.

From my perspective, the issue here is where do you build the outer ~7m/22' long outer panels? You're not building those in a standard one-car garage (or single stall of a two-car), even if you go diagonally. Add 2' to the 22'-long panel for the stub-spar and you end up with a 24'-long build piece. Add tool clearance and the ability to simply walk around the thing, and it just won't realistically fit. That's an awfully big wing panel to be building at home. "Conventional wisdom" now (i.e. - "what everybody knows") is that sailplanes must be built of fully-molded composites, but for a mid-performance ship, I heartily dispute that. Of course, if 40:1 is "mid-performance" as it seems now to be for the overall community, I may well be wrong.

Agreed. I don't know the solution, though. My best thinking is that the community, if it wants growth, is going to have to re-embrace 30:1 ships and not-flying-for-competition as "real flying," so that less-expensive options can actually get community support instead of hand-waving dismissal, but I don't know how to change human nature.

Well, wait a second. You're making the very strong assumption that a carbon-fiber mid-/high-performance sailplane is the only way to go. I question that, as a fundamental assertion. I hear a lot of people, here on HBA, at the ESA workshop, and out in the world, asking for a small, simple, semi-touring motorglider. I'm looking for one myself. Your product is magnificent, but it begs the question of whether that much performance really is necessary to have a viable product, or even to "just have fun" soaring. The "conventional" soaring community seems to think so, in my experience, but I'm pretty sure we've been seduced into thinking you have to have a Ferrari to enjoy driving. A Miata sure has been a popular option for a lot of people who just want to have fun driving. What's the soaring equivalent of a Miata?

Isn't that just a variation on the same old argument that, if they can't afford a high-performance carbon ship, they should just "eat cake" and scrape up some basket-case used glider, which is what the remaining Monarai's usually are? I'm not trying to be offensive, because I hope you know I hold you in the highest regard, but I think that myth has to die, and die very hard, if soaring is going to survive. If "real soaring" can only be a 40:1 carbon ship that needs a tow-plane to get up - if that is "the truth" - soaring is going to continue dying, IMHO.

Or maybe I'm wrong. Could happen. Happens a lot.

Last edited: Sep 4, 2019