And then I sat down and did it myself, designed a housing, designed the circuit board, tweaked the software a bit for my hardware, and in the end, I had a vario with a display that actually worked with GPS and an accelerometer, and that was really the game-changer, so I was really on top of it in real-time. As soon as there was even the slightest bit of climb, it showed it. Yeah, and then I had the first vario and that's when my flying colleagues started showing interest. Podz-Glidz,
the Lu-Glidz podcast.
Stories from the cosmos of paragliding.
Today with Frank Littemate. And I'm Lucian Haas.
People know and admire them as a kind of Daniel -Jetpropulsion or MacGyver. Men who somehow always carry the right tools, tape measure, soldering iron, hot glue gun, spare line, shackles, or 3D printer on them, to create useful things out of necessity or pure inventive spirit that would otherwise only be available for a lot of money. Frank Littemate has been one of those cases since his youth. And since the now 57-year-old from the Porta Westfalica area started paragliding eight years ago, he has dedicated his passion for tinkering and DIY, above all, to this hobby. The results are, on the one hand, very practical things like a board for correctly laying out the line, a loop for the rescue, or a holder for the tools.
But he has also come up with products that would otherwise only be available as expensive specialized instruments. A line measurement system, a porosity meter for paraglider fabrics, or a Betzometer to determine the tear strength of fabrics, for example. All of these do-it-yourself versions cost him only a fraction of the professional solutions but deliver very similar results. How Frank comes up with such ideas, and more, he tells us in this episode 156 of Podz-Glidz. It also covers, among other things, his final unsuccessful project: financing the development of an entire paraglider through crowdfunding.
Since you're listening to the podcast, why not become a supporter of Podz-Glidz? It's very easy to do—you can find out how on the Lu-Glidz Gleitschirm-Blog, specifically on the "Support" page.
Frank, have you ever actually been called a Daniel Düsentrieb? Yes,
Daniel Düsentrieb or tinkerer. Thermik once called me a tinkerer when I developed my do-it-yourself vario and they tested it. Exactly, but Daniel Düsentrieb has also been mentioned.
Where does this urge to tinker come from?
Yeah, basically as a teenager. I'm 57 years old, back then there were no smartphones and leisure time was a bit different. It took place more outdoors. And the first project I did was the high wheel. The first project I saw was somewhere, I think on TV, someone had a high wheel like in the circus. I said to myself, I have to have something like that, and then I got to work getting the parts, having them welded, and so on. And that was a success. I built a high wheel about two meters tall and could ride it around after some practice. And then I also repaired things like mopeds and used my father's workshop intensively. Yeah, and from that, the interest in building things developed somewhere, certainly through the success of building things, and that actually carries through to this day.
How does that connect to paragliding? I mean, that was your tinkering experience as a youth, but I don't think you've been paragliding for that long.
No, I've basically been paragliding since 2017; I did the training and then got my B-license shortly after, because the GST club still has quite a few cross-country routes today. Exactly, but before that I did model aviation, which is closer to the subject, and I already developed quite a bit there, and even developed aircraft with the aerodynamics, for example.
So you basically designed them from scratch, decided which profile they should have, and then cut them accordingly?
Right, exactly. So with this model aviation, I first started working my way into it, and at some point, it was like, these wooden models were relatively quick to break. And then it occurred to me back then that the model planes you used with paragliding—the ones used with the paraglider—could be made out of EPP, which is packaging material, so from polystyrene wings, which obviously last longer. And then I used a hot wire machine to cut these profiles myself or cut them out with a hot wire. Yes, and then at some point I thought, okay, how do I manage to make the model fly better, fly faster, or maybe even fly slower. And then I got into this topic of aerodynamics and looked into airfoil shapes, about the washout. For example, I also once built a model that flew incredibly fast; it had no washout.
And I heard later that with kites, there were cases where they'd get into these fluttering dives. That's basically what happened with my model too; you could fly incredibly fast. But at some point, it flipped over and was practically uncontrollable. That's when I started slowly working on my designs in that area and learned quite a bit about aerodynamics. Like, why do planes fly slowly or fast, wherever that may be. Why are they dynamic or rather sluggish.
In 2017, you said, that's when paragliding happened. I mean, as far as I know, you live in the flatlands. How did you actually get into paragliding?
Yeah, that was basically a coincidence. In 2017, we were in Marquardtstein and hiked up to Jena with the family. And then there was someone with a big backpack who started unpacking. My sons and my wife wanted to keep going, but I said, "No, let's wait a second. I want to see what he's doing." Up until then, I had never seen or noticed a paraglider. And then he unpacked. His fabric hung there, waiting for the right moment. Probably until the wind came from the front. And then he took off. I thought, "Okay, now I'll watch until he flies down, and then we can keep going." But he didn't fly down; instead, he turned up in the thermals and stayed up there. And I thought, "Oh, that's impressive." And my wife and my sons know me—if something grabs me, it can quickly become an addiction.
Yeah, and so we drove home. And I immediately looked up whether there was anything like that here in the flatlands, and I found something relatively quickly in Sauerland with Reinhold Schöttler. He had a small flight school and signed me up for a trial course. And I'd say, compared to other flight schools, it was quite something. On the first day, you did a bit of ground handling. Then you flew down a small slope. And on the second day, you actually flew down the 80-meter slope in Wirminghausen, of course without thermals. I was pretty hooked because I thought, you can start flying here that quickly. And I signed up for the license right away.
Now that you've started flying, when did it happen that you started thinking, this DIY urge is mixing with paragliding, and you said, I have to start building or constructing something for paragliding?
Yeah, well, in principle, I already had that DIY drive back in model aviation. I developed things there too, and I also had this little model building project running on the side with my little inventions, let's say. Yeah, and when I started paragliding, you eventually find a need somewhere. The first need was practically me saying, okay, I want to pack the reserve myself. For that, you need a packing board. And I already had a milling machine from model building, so I first constructed this packing board where I can adjust the width of the loops with these pins and then pack my reserve accordingly, as a little tool instead of doing it by hand. That was the first practical thing I did. At some point, of course, I also needed a vario.
I had bought a very old vario, it was already 15 years old back then. And it was always so delayed. So when you entered a thermal, you could already feel it lifting you up, but no tones came out. And when you were already sinking again, the beeping would stop. So I basically looked on the internet. There was this vario, someone had developed the software based on Arduino components. And then I sat down and did it myself, designed a housing, designed the circuit board, and adjusted the software a bit for my hardware. And in the end, I had a vario with a display, a Nokia display, which actually worked with GPS and an accelerometer. And that was actually the game-changer. So then I was really getting real-time data.
As soon as there was even the slightest bit of climb, it showed that. But if you swung through, it didn't, because there was a filter built in. Yeah, and then I had the first vario. And that's when it started, my flying buddies were interested and other colleagues were interested. And then it went in the direction of me finishing the products and offering them as well. Do you still fly with your DIY vario today? Partially, yes. I even still get inquiries about that vario, where people want one, or they're flying and need a spare part. But I have to say, I stopped the project after a year because I had offered it as a kit and as a finished module, so that it was really ready to use. Yeah, and with the kits, they were 10 euros cheaper, I think it cost about 60 euros in total, and then people soldered it together,
but some didn't have the knowledge. And it was incredibly demanding in terms of support. There was mechanical stuff to build, things to solder, and software to upload and configure. It just became too much for me in terms of support effort, because it was more or less a hobby, not something you can offer commercially for that price. So I stopped and sold off the remaining stock. But I still get inquiries today, and honestly, it's still my favorite Vario. The only reason I don't use it as much now is that it only supports Bluetooth 2.0. I fly with XT-Track and my phone only supports 4.0, which is why I fly with the MiPi-Vario now. But you could keep developing it.
In a way. Yeah. Or would that be too much effort?
Yes, that would work. I've already looked into it. There are modules, which are all individual components you can build in. But as I said, based on my experience with the time required, the support, and so on, it's very labor-intensive. And MiPi-Vario is a commercial company, and I got in touch with them and the developer, who is practically a one-man operation as well. We exchanged ideas. I also helped him flash something for his projects. So, in principle, I'm still involved in that topic, but I'm now more or less helping him out a bit and he helps me. So the Vario topic hasn't let me go, but it's not under my responsibility anymore.
Yeah, I noticed when you started emailing me saying, "Hey, I've developed something new again. Maybe you want to announce it on the news ticker on Google Ads." And those were always auxiliary devices—I'll call them auxiliary devices for now—that somehow have something to do with checking. And you developed a Porosimeter, a device with which you can now measure the air permeability or air permeability of fabrics yourself. And then, for my own fun, I looked up what a Porosimeter, such a JDC device, actually costs if I buy it. And I saw that you actually have to shell out well over 1,000 euros for it. And then you found a solution. I think that thing costs 70 euros now, the way you're offering it.
What drives you to say, "Hey, there are expensive solutions out there, I want to develop something DIY myself"?
I'm a pilot myself and I'm also interested in the technology. So as a beginner, you buy used gliders and think, okay, it still has a year left before the check, hopefully nothing bad happened and it won't make it through the next check. Or you're launching, you've dragged it across the launch site a few times because you didn't launch cleanly, or maybe it opened once, it
I'm a pilot myself and I'm interested in the technology. So as a beginner, you buy used wings and think, okay, it's got one year left on the check, hopefully nothing serious happened and it won't make it through the next check. Or you're taking off, you've dragged it across the launch site a few times because you didn't take off cleanly, or maybe it opened up once and...
put some thorns on it. You always thought, oh, what's up with this check? Will it pass next time? How does the glider develop if I'm dragging it while winching, if it sits in the sun for a bit too long? That's actually always interested me, and I thought I'd like to have that measurable. And like you said, I looked into it, you can probably buy those devices. And then I saw, okay, I'm not a check operation, I'm not going to spend 1,000 euros privately just to measure porosity. And so, bit by bit, I actually developed every device to a hobby budget for myself. And as it always goes, once word gets around, others are interested too. And by now I have to say, even internationally to Malaysia, Singapore, to South America, those checks aren't even mandatory in some places. But I've also now...
received and delivered orders, because there apparently is a demand for low-cost devices.
How do you basically come up with the ideas to make it that simple? For example, with this porosimeter, you're basically working with a bucket of water and, ultimately, a kind of PET bottle, let's say, simplified. You have several markings on it so you can see how the water level drops and how the air passes through, and stuff like that. And you also have a magnetic seal ring that you can wrap around the fabric area with a hose connection to the bottle. How do you come up with a solution like that? Did you first look at a real porosimeter, sort of, and say, "How does this work? How can I simplify all of this?"
Yeah, I first looked into the theory. It's such that a pressure of 10 millibars must be created, actually constant, and this pressure acts on a 37.5 square centimeter area of the fabric. With this theory, I thought, okay, how do I get this pressure without using that solution with the pressure gauge and the digital clock, which, as you said, costs 1,000 euros? I thought, okay, a water column would be the right thing to start with. And then I did some research and actually found someone who did it that way, with a bottle, but I'd say, not with printed parts, but also in terms of the seal and how you have to handle it, just a bit differently. Then I thought, okay, since I have a 3D printer now and can also do the drawing,
I did it in a way that's really reliable and works well, practically just like the standard device, and then I developed it. Then I bought a special measuring device from the heating industry that measures exactly in millibars and verified it again, because first I calculated it—I can calculate all of that, where the marks have to be and these height differences—and then I actually measured where the pressure is in the middle. It's a bit higher at the beginning, it goes from 12 millibars down to 8 millibars over 10, and I measured that with a normal device. By the way, Cross Country Magazine and Fly with Greg, for whom I occasionally translate, did that too, and we found out there's no difference compared to the other devices, maybe plus or minus 2, 3 percent, but that could be due to whether I'm operating the stopwatch correctly.
exactly, and I saw, okay, this works, and now I also measure my gliders with it and others are doing the same now. Did you study physics or something? Well, physics was already in school, so I, let's say, I was good at it, I understood it well, but I worked out things like this myself. Today it's of course easier than before; way back when, you would have had to read books that were sometimes not easy to understand with all the formulas. Today, of course, you can also watch videos on YouTube and so on. So in principle, my motivation whenever I have an idea, which might be really complex, is to first work on the theory with the help of YouTube, with books, with communities where you go in and exchange ideas, and then to utilize that and finally build in the solution.
Yes. A
the other device you built is a bezometer, for the fabric's tensile strength. How does your bezometer differ from professional solutions?
Yes, in principle, this scale—it actually is a scale—is purchased for what's at the front, and that's why the device is so cheap. I think the standard device costs 70, 80 euros, while mine is maybe 20 euros. Exactly, in principle, there's this needle at the front; I checked, and the needle diameter is standardized, and it's a 3D-printed part, and then the whole thing is screwed together, plus this standard scale you can order. So, something with practically the same function was created, which might not be quite as good in terms of stability, but it can even be calibrated. So, in terms of measurement accuracy, it's great and is well-received, and I've also gotten positive feedback. Hannes Papisch even ordered one from me and wrote something nice about it, saying he's happy that I'm developing such products; of course, I was especially pleased that a luminary of paraglider development gave me feedback.
Do you know if other, say professional check centers, are actually using your devices now?
Well, I only know from the overview of the orders in Austria that a new check operation has started—there's no demand from existing check operations, but check operations that have just started are ordering one or two accordingly. You can see from that that they are companies or paraglider operations. And as I said, internationally, I was very surprised that word got around. I assume it's because of the Cross-Country report, as they tested these pieces of equipment. It then made its rounds internationally and led to there being an interest.
These devices you've developed now—to what extent do you use them yourself, or let's say, regularly? Is your interest so great that you'd say, I have my own glider, I'm going to measure it every month and after every flight, or however, I'll measure how the fabric is developing, because I just want to know how fast my fabric is aging, for example. Do you do such series of measurements for yourself as well?
I do that too. What I don't really do is, in principle, this fabric tear test where you stick the needle into the fabric and pull. People don't really like doing that. It's not harmful, it pulls back together. It's a fabric that's interwoven. To be honest, I don't do that very often. But for example, the line lengths—I'm flying a two-liner at times now, and a two-liner is already sensitive in that regard. There's hardly any load on the B-risers and almost everything is at the front. And if those shorten, it gets slower, the glider might also become less stable, risk of stalling and things like that. I do apply that, though, to see how it's developed after three months or half a year. And this Chorysimeter to measure the air permeability is, of course, simple.
Just put ten liters of water down, more or less submerge this bottle, put this clip on the fabric, pull it up and wait. The longer you wait, the better. If it waits for 300 seconds, then the DDC value is 300, which is good. It would be bad if it were only ten seconds, then the fabric is practically unusable. So I do that regularly because it's relatively easy. For example, towards winter, I've checked my gliders that I have again.
Have you noticed anything yourself where you're like, oh, I wouldn't have thought that, for example, porosity would get worse so quickly or stay clearly good for so long?
Yes, I can only confirm that. With light fabrics, people generally say they're actually just as durable. But I'd only sign off on that if I were theoretically only launching on nice grass fields, if I didn't leave the glider unnecessarily long in the sun, like during a winch tow or at the launch site when I have paragliding. I mean, if a light fabric... for example, at Portes, they've paved it because there's also some activity there, I think it's similar to at Brem, where we met before, there's also a restaurant up there. Exactly, if I have conditions like that where the fabric gets dragged over something, like stones or whatever, and then it sits in the sun, I just don't believe they last that long. I also know two where the glider didn't even pass the second check, exactly because of the porosity.
Do you have many club members who come to you like, "Hey Frank, can I have my glider measured by you or something?"
Yes, incredibly many, but I've had colleagues come over with their own gliders because they're interested, or because they had offered their glider on the DHV and someone was interested and said, "Oh, the check only has four months left, but I'd like to have current values." And then they come by, he takes me with him, I take my line length measuring device, enter the line plan, and then measure once to see what the line lengths look like right now. It's also graphically displayed in color whether that's okay. And we can also measure the porosity right then, and then he can tell the interested party with those values, "Here, this is how it looks currently."
How important do you actually think it is to check your gliders every now and then? A typical pilot will always say, "Well, you go about it relatively... how should I put it, I think many pilots are relatively uninformed about the whole thing and say, I get the glider checked every two years and in between I just fly it and don't worry about it anymore." To what extent would you say, also based on your experience, that it's worth it to check your gliders a bit between times for yourself? And what would you recommend? Which checks should you do primarily?
Well, basically, I think anyone who flies a lot or has incidents—like if the glider might have gotten wet and was packed up wet and sat for two or three days. Or anyone who flies competitions. Competition pilots are also part of my clientele, who need an absolutely perfect trim with the two-liners so that the glider has the optimal performance. Or, as I just said, private people who had those incidents where the glider might have gotten caught in a bush somewhere during landing and they're not sure if some line stretched. Or, as mentioned, the glider in the hall, flying in salt water at the sea, getting dunked, and then being washed and dried properly. Does that have an influence on the porosity? That certainly depends on how much I fly and what happened to the glider.
So for high-frequency flyers who also go to bad launch sites, I would definitely recommend it. A lot can happen after two years. You can see that gliders hang, they don't launch well anymore. I know many club colleagues who send them in for a check-up and say, somehow the glider isn't good anymore, it launches and hangs back, and then it turns out the
glider is no longer good. And
You can of course find that out very well at home. You're also allowed to change it yourself. Of course, everyone has to know for themselves if they have the corresponding knowledge. But if you know that something isn't right and you send it in, you can already say, "Look, something's not right here, adjust the trim," so that's already a realization in itself.
Actually, it might be sensible if you basically buy a new glider to measure it yourself once and say, what's the original state, roughly, what are the permeability values of the fabric, and maybe also have the lengths so you know, okay, that's how it started, and then after 20 hours or half a year or whatever, depending on how you flew it, you can do some actual comparisons and maybe get a feel for how quickly a glider changes and ages. Do you do that with your glider?
Yeah, exactly. I offer these custom gliders, which is a side brand of mine, more of a hobby because I also like to fly, let's say, brands that aren't so well-represented, and I actually measure my gliders. There's also this two-liner, the Vega 6 from Axis, which I measured. I know the values for how it's supposed to be delivered, so I can really look at it as a reference after half a year and see, okay, have the B-lines actually shortened or not. And with my other glider, I noticed something while I was out; at this point in time, it's already the case that it sometimes gets wet, then it lies there on the landing field, and even though it's dried quite quickly, I've also noticed it flies somehow slower. You can see that even in almost zero wind. Otherwise, it flew 39, but now it feels like 35 to me.
Then I measured again, and actually, the C-lines had gotten a bit shorter, so I quickly clipped them into my line measuring device and stretched them a bit with five or six kilos, and then they were normal length again and it flew normally fast again.
You just said it, Axis Paragliders. You're the representative for Germany for them. Yes, that's correct. What's your take on that?
...come about? Yes, I said that I like to take different paths than a normal pilot, let's say, who says, okay, which three, four, five top brands are there, then we pick a glider according to my class and fly it. I like trying things out, and I had researched and seen on this Axis side that they were still looking for a dealer in Germany, so I just got in touch and, let's put it this way, it's a company where there was no minimum turnover. You can talk to the boss. I was even there on-site. We can talk about it again right away in a week. So it's incredibly approachable and for me, it was practically no risk to take it on, I tried it and I'm by no means disappointed.
I fly the gliders myself; I've put in some great test flights with them. Of course, I also bought them at good prices and pass them on at good prices too, because as I said, I don't run the whole thing so commercially. Exactly, I've had good experiences there, and that's why I now have two other small brands that aren't so well-known here, because with the big brands, there are minimum turnovers you have to achieve and stories like that. For doing this on the side, I didn't want to start that accordingly. There are plenty of others who take that on.
The other two brands you have are Sky and DaVinci. Are you officially their representative now, or are you just a dealer who also carries those two brands? So...
With DaVinci, there's a main dealer in Germany, but he only does motor gliders. And I actually had inquiries for DaVinci. They've released new gliders and they fly very well. And I also had inquiries from people who already fly DaVinci gliders—they've been flying a D-class glider for four years and wanted to move down to the C or B class. And then I noticed it and said, okay, even though the brand now comes from Asia, from South Korea, there seems to be an interest. And I said, okay, then I'll just order the glider for the customer and one for myself and test it out. They are good gliders too. I have to say, I think no bad gliders are being produced at all these days. It's more like, I want an agile glider, I want a fast glider, and that kind of stuff within the class.
That's more of a matter of taste.
Let's just say, the heart and soul of the brand would continue to be Axis.
Yes, that's correct. The Axis gliders are there. The only thing is, with Axis, of course, anything is possible for the small companies. It's very difficult to certify all sizes all the time. And Axis didn't do that either. They certified two or three sizes, the main sizes. And when it comes to other sizes or a different flying style, like Sky gliders, for example, they have that very typical Sky handling. So, I can offer those Sky gliders. And Sky, now through this Drift merger so to speak, they've also gotten some new developer blood into the company. And the gliders are good too. So I think they can be recommended. In the end, it's a matter of taste, which flying style you prefer and whether you maybe want to have medium-weight light gliders.
Well, you started a very interesting project with Axis about two years ago. I also reported on that on Loglites. You did a crowdfunding campaign and said, "People, through crowdfunding, you can basically buy shares here and participate in the development of a high-B glider. It was supposed to have a 5.8 span and become a 2.5-liner and so on." And you said, "Okay, if you participate via crowdfunding, you also have a certain say, and in the end, you get the glider particularly cheaply." What came out of that? No, let's start differently. How did you even come up with the idea of doing something like that? I mean, in a scene that normally isn't at all geared towards people saying, "I'm financing a glider in some way before it's even hit the market."
So basically, I had the idea: okay, this typical marketing that exists in that field, can't we do something completely different? Just out of curiosity. And then I discussed the idea with Greg Hammerton and he said, okay, if one of the best designers did something like that, then it might actually work. I'd say, if you're not that well-known, it would probably get less attention and might not even make you more famous. I had also brought up the idea and we talked about it. You basically said something similar. But I said, what do you have to lose? We could just try it. It's a completely new idea and I'm all for new ideas. I said, okay, then I'll just drive to the Czech Republic; I had talked about that with Axis.
They said, okay, we can do that. They aren't that strongly positioned from a marketing standpoint anyway. And then I was there for a week and met the developer. We spent the whole week with his test pilots. I looked at the idea four times, and of course, filmed a bit. So it was super interesting to see how a paraglider is created on a PC with all those calculations. It reminded me a bit of my wing development times. It's actually somewhat comparable. Plus, how it's produced and tested. I was there on-site where they did the final fine-tuning. So, they actually go to the C-line and make it two centimeters shorter there, a centimeter longer here, and then they see, okay, how does it fly then? So it was super interesting. And then I said, it would certainly be interesting for any pilot who is interested to see that.
And that's why I included the idea of a sort of on-site visit in the crowdfunding. But as expected, there weren't enough pilots who said, "I'm joining them." A paraglider costs a relatively lot of money; it's not like an MP3 player where I put 60 euros into the crowdfunding and get one at the end. It just didn't happen. But as I said, for me, it was super interesting to experience all of that and to see how it develops. So, based on my personal experience, I would do it again anytime, even if at the end of the day it cost me a week of vacation and, of course, a bit of effort to coordinate. Did you have any interested parties at all? Yes, I received a lot of feedback. Some amounts came together, but no one directly bought a paraglider, so to speak, blindly.
It didn't go that far. The smaller things, like a T-shirt or a donation, those were actually, I'd say, ordered. But in the end, if that target amount isn't met, everyone gets their money back and it just doesn't happen. And that's how it turned out in the end, because the target amount was also relatively high because of the development costs—to be able to certify at least one or two sizes. Certifying one paraglider size costs 5,000. If not two, I'd have to have 10,000. That's why the sum had to be so high to even start something like this.
What did you learn from that? Or if you were to do something like that again, if at all, what would you do differently? I mean...
I'd say, in a way, financing a paraglider through crowdfunding, my conclusion is that it's probably not feasible. I mean, the pilots—there are plenty of gliders on the market, and they test them out and then buy them. Apparently, the interest from pilots isn't that high to the point where they'd want to be involved and contribute their personal wishes. In that sense, I wouldn't do it again. I didn't do the other things I developed and brought to market that way either. I didn't do those via crowdfunding, but rather because they were feasible and were released in the first step just for myself. And they did well. So, in that sense, I wouldn't launch this crowdfunding paraglider in this form again, of course, because I've had the experience—the positive experience.
And that was good. But again, I wouldn't have to do it now.
Well, you're always looking for new things you can develop further. You're just a tinkerer at heart, probably. So, what kind of idea do you have in mind right now that might surprise the paragliding scene again, both in terms of the solution and maybe also significantly in terms of costs?
Well, in principle, it's not my idea. We are a winch towing club here, and sometimes it's just like, we have this big two-drum winch, which is an electric winch now. But we can't always get a towing operation together during the week, let alone on the weekends. Sure, we have the Sauerland nearby, so the small mountains, the Porta Höxter, where you can fly. And when it's flyable there, it gets spread out. Then some people say, okay, I prefer mountain flying, and then nothing happens. And that's why there is currently one—someone from Austria built it—an electric winch with one drum, with an electric motor, like the ones basically used in small cars, plus a controller, plus the technology where you can do a self-tow.
And that means it's a special remote control, a special board with an antenna, which is also certified. With that, I can practically have the winch operator tow the pilot with a remote control up to a certain safety altitude. Then I can increase the pulling force, just like with a normal winch. And then at the end of the day, when I unhook, it even automatically reels all the rope back in up to ten meters and then lays the glider down. And with that, I can do a self-tow, which the developer from Austria also does. He tows himself up, flies around, goes on a route, and picks up his gear at the end. And someone from the club has rebuilt it in that form. First, with a bit of a learning curve, because all these mechanical issues and so on are of course no small matter.
And then we have the former German kite flying champion, Bernd Otterpoel, in our club. He's also super fit in terms of development—mechanically, electronically, all topics. And he's taken it upon himself to offer the whole thing as a do-it-yourself project once it's finished, so that there's a components list, all the plans are there, and people can basically have these parts manufactured and build the winch accordingly. And then you have a battery depending on the size. I've already bought the parts for myself. I can do about ten to twelve tows with it, which is enough for a small towing community of two or three people. On a good day, you basically have thermals and can fly. Yes, and that should then be documented and available as a do-it-yourself offer.
That would be the next project I'll be getting involved in, building it myself and then maybe helping with the documentation or publication, as it is, since it will certainly need a bit of support. The question is whether it will happen, when it will come, and how fast it will come. Because of his connections as a kite flyer—since he also has close contacts with the DAV—Bernd Otterpoel is already looking into the possibility of getting approval for self-towing. And if that happens, it would be great, because then you could say, okay, the small towing community still needs someone at the end there to operate the winch. That would be moot. Then the last person could tow themselves into the air, and practically everyone would be taken care of and could fly. If it gets approved by the DAV—I think there's already a pilot program for that—that would be great, of course.
If
Since you build so much yourself, have you ever thought about building an entire glider yourself?
Yeah, I'd say I wouldn't dare take on a glider like that right now. I mean, in principle, it's incredibly difficult to sew. I know, for example, a two-liner that's internally braced—skilled seamstresses sit on that for four days alone, just sewing all those cells and, in principle, the pockets for the rods and so on. So that would be too much work for me. To do it, the result you get out of it. I think I'd leave that to people who can do it and do it as their main job.
But what you've developed from a sewing perspective—you once developed a tow release, a textile tow release, but with a special function. What is that? Exactly. So there,
The history is also, as almost always, a matter of personal need. We have the possibility at our club to do multi-stage towing with the new winch, but also before that, which is a real advantage—that I do several stages, and if the thermals then happen to pass over the site and I'm still on the line at my second stage, then I can enter the thermals exactly and climb up. So the probability of finding a thermal connection is relatively high. And I got the certificate. We were on a team trip at the Müritz, and the only approved towing winch is now this metal bracket that exists currently. So, this metal bracket. So, approved towing winch, you mean for multi-stage towing? Right, exactly. And yeah, this metal bracket, well, I'd say, I fly with the Handy and then with my little Vario on it, and if they unhook, then this metal winch falls down onto my instruments, and I thought to myself, okay, there are also nice fabric winches, completely normal, but without multi-stage towing approval.
and thought that would be a good next project, now that I need a winch myself, before I buy a metal winch, which I believe is no longer being offered. I think there isn't even a supplier for these winches at the moment. So I tried looking into it and researched, and there's a Thomas Jiergal who had already started the topic with the DAV, where basically the side pull forces work with springs and release at a certain spring force, but it dragged on for quite a long time and didn't get approved. I don't even know, it dragged on for years and in the end, he also abandoned the project. And I then thought, okay, the thing with these springs doesn't seem that reliable either. The release force has to be between 25 and 45 kilos.
and then I realized that a magnet actually has a very specific release force, so I solved the whole thing using a magnet. Exactly, if you have a trapezoid like that, where you're being pulled, once you reach a certain angle, the force goes onto the magnet and when it releases—the magnet detaches because in my case it pulls over 35 kilos—it releases the pin and you unclip. Yes, and I then sewed, made, tested, and measured it as a prototype. I also measured my own development, this load device, because it has to withstand a breaking load for a 300-kilo approval. So that was quite a long development process, also in close coordination with the DRV. And yes, and in the end, I managed to get this clip approved, so that it works within the specifications and simply works 100%.
I think it weighs about 180 grams, so the latch is quite light and also portable, because the number-slurs plus that fabric part sewn on the front with the periphery can be packed quite well. Exactly, that was the goal, and it worked out at the beginning of last year.
With magnets, you can really determine things so precisely that you can say, okay, I need a magnet that holds 35 kilos. So can you just order one like that somewhere and say, I need 35-kilo holding force magnets?
Well, one side is the magnet, and the other side is a metal plate, so something magnetic. I obviously had to experiment. I ordered different magnets and the opposite side was practically a better washer, let's put it that way. And it then depended on the thickness of the washer. I tried a lot of different things to find the optimum, because I definitely wanted the whole thing to stay light—not using unnecessary amounts of material, not an unnecessarily heavy magnet, or an unnecessarily heavy plate. I did dozens of trials and in the end, I found the right material that works exactly according to the specification.
Maybe there are some pilots who don't know exactly what step towing is. Could you explain that briefly?
So, normal towing is like this—let's assume it's a classic winch, it's standing somewhere at the beginning of the towing field, and the pilot is at the end of the towing field and gets pulled up by the winch in the classic way. So there's a tow line involved, and then he's pulled into the air to a safety altitude of 50 meters, and then the winch pulls full power, and then I fly practically right in front of the winch, or I'm at a certain degree in front of the winch. Yes, and then I release, and depending on the towing distance—if I have 800 meters now, I might have 350 or 300 meters of release altitude, or if I have a 1,000-meter tow, I might reach 450 meters, which is also the absolute maximum I'm allowed. So, I release, and if there's no thermals right then, then I'm out of luck.
Then I'll land relatively quickly again, because 250 meters of altitude, you can do the math, isn't long. So, with the step tow, the idea is that I want to stay on the line longer and I let myself be towed forward in the classic way. Then the winch has to be able to do that, to be uncoupled, and then I can fly away from the winch with slack line, all the way back again, and can already see if there's maybe some thermals, if it goes up a bit there. Then I make my turn and I'm calculated to fly back towards the winch again, but I'm already higher. So, with this short tow distance where I only have 350, in the next tow—which I'll already have 100 meters of altitude if I fly back or 200—I can get even higher to the maximum 450 meters that are, for example, allowed, and I've flown the entire area twice, basically three times with the return leg, to see if there's any thermals.
And that increases the chances immensely that I'll find a thermal entry and then stay up there.
So, if you're being towed now, do you always fly with your tow release and do step towing as well?
Exactly, if the site has the authorization. We have two sites. The short one has a staged tow authorization, so I do it that way. But now we also have a glider site where the distance is 1.1 kilometers. It's not necessary there and it doesn't have authorization for it either, because I'm already reaching the maximum release altitudes anyway. In that sense, it's not practiced there. But especially with short sites, if I have a tow distance of, say, 600 meters or 800 meters, it's definitely worth it.
Based on your experience with what you've done, would you say where is the entry chance actually greater in the end? Having the longest possible tow distance or rather having the option to be towed in stages? I
I'd say with the staged towing, because practically speaking, I'm on the rope longer and the thermals aren't stationary anyway. Maybe at some sites they are, but not at our sites. And sometimes there's just no thermals at all. If I have a longer towing time, then the thermals that maybe weren't there before start forming again at the site. So, as they say, the probability increases significantly that I'll get it on the first rope—meaning the staged tow rope. Of course, it's 80 percent if it's a thermal day, whereas it might be 20 percent with a normal tow. But it's just that the others have to wait longer. It's true that the other pilots on the ground have to wait longer too. But if I'm just doing yo-yo flights all day and no one stays up there, that's not the goal either.
Then it's better to do this staged tow; everyone waits a bit longer, but at the end of the day, almost everyone is up there.
It's probably also the case that if you're towing with relatively short distances—you just said 350 meters or something—you basically towed that distance quickly. And probably with one or two flights back, it doesn't take that much longer than if someone were being pulled up with a 1000-meter rope.
Yeah, that's exactly it. I mean, let's say our distance is about 800 meters. I've also heard 600, I think 350 meters. That was
the release altitudes. Release altitudes. Okay, I mixed those up. Sorry. And if you're tinkering this much and doing so much—clearly approaching things very systematically and always thinking about what you can do—are you that kind of pilot?
Yeah, so last year I flew quite a bit, almost 100 hours. Of course, last year I was lucky; I was in Bassano twice on good days, and then someone from the club offered in our WhatsApp group that I could fly to Gimona with them. But I didn't know the colleagues at all. I just got into the car, we drove there, and I was lucky enough that on the first day I flew from Gimona to Tolmin, almost all the way to Tolmin, and back. Wow. And since it wasn't a super strong day and I didn't know my way around at all, I had to find my way back alone because we'd somehow gotten lost, so I was on the road for six hours. And six hours of flight time is quite a lot. And there were also days where it was only half an hour of flying, where we flew to other flight areas somewhere.
But I think I had about 18, 20 flight hours that week. And it was similar in Bassano. That means, just from these three trips alone, I had about 55 flight hours, and the rest was here accordingly—here our highest point, Korta, Sauerland, plus winch flying. That's how it all added up. But what I actually,
where I was leading with that question: are you basically a stubborn pilot, or do you also have a very intuitive side when you're flying? That's what...
In any case. That comes from model aviation alone. I told you that. So, in model aviation, I did almost exclusively slope soaring. There was a small forest behind us and a hill with a plateau in front. And back then, even with model aviation, I already noticed, okay, with this wind direction, I'm flying my model plane into the tree line and it goes up. Or in that hill, when I'm in this plateau, there's some kind of vortex in there, a kind of lee effect, it's hard to land there. And that's practically still in me today. So when I fly, I'm looking the whole time for where the drop-offs are, where the movement in the trees is. And sometimes I actually don't try to listen to the vario at all, but just see where the glider is pulling, I let it fly there for a bit, then I see, okay, that fits so far.
Exactly, I think it's extremely important to work with all your senses and the experience you have, especially in flat country, because I spend a lot of time there. And when you're out on a cross-country flight, you see from below, okay, if it's a good time of year, there are grain fields, or if I'm flying away from Porta, it goes along the Weser with a few Weser loops. That's actually a good ridge point too. So you really have to look, you have to read the terrain. And if you do all that, you definitely have better chances of being successful out there. What do you wish for...
...still for the future? Regarding flights or things that could run even better with Parafly24?
Yeah, let's start with Parafly24. Basically, the current status is that I've achieved what I wanted to—I have the gear I wanted to have. But that doesn't mean I won't have another idea in a month and the whole thing will start all over again. I'm curious to see what else you come up with. Exactly, that's the standard range I represent for now, and I assume it'll stay that way until the next idea. Exactly, and regarding flying—I'm lucky that I still have to work for another year and a half. Then I'll be on partial retirement and I'll obviously be able to choose my days better, which isn't the case at the moment. When I'm here at home, you can sometimes see those beautiful thermals from my study, but you just have to work.
I'm already hoping that I'll get to fly a lot more. And honestly, I have no qualms about flying cross-country, even if I have to somehow get back. Because I did a lot of hitchhiking as a teenager. And when I had to apply that again during my first cross-country flights, I was picked up by people who used to hitchhike and said, "Oh, I used to hitchhike a lot too." It's great that people are realizing that again. Or young people picked me up and said you should hitchhike at least once in your life. Today is the day for it. And I've had great experiences, even in Italy; in Bassano, I didn't even get back. So hitchhiking is so much fun. It's just part of who I am. That's why when I land, I usually don't even check if there's a train station or a bus connection, because I think: you fly as far as you can, and the way back is an adventure.
So, another old-school pilot, from back when there were no cell phones, when you still had to build everything yourself, didn't have a car, and hitchhiked everywhere. And you're still doing that today. Frank, thanks a lot for your story. I find it very inspiring how someone can put so much imagination into products and really create great things. I wish you much success with it, and of course, especially with the flights. May there be even more of them when you're actually retired in two years.
Yes, I want to say a huge thank you for the interview and for having me on, and I wish all the pilots a great season this year. Thank you so much.
Now, at the end, I have to catch up on something for Frank. Because although he firmly intended to, he forgot in the heat of the moment to thank his wife Tanja in the podcast, who supports him so much in everything, in all those DIY hours, but especially in the accounting and sales of his small company parafly24.de. I am very happy to pass on this thanks. Just as we can only thank all the flight wives and also some of the flight husbands who have their partners' backs for the most beautiful hobby in the world. If you enjoyed the episode, then tell your flying friends about it. And if you know someone who you think could also be an interesting guest on Podz-Glidz, then tell me about them.
I'm always looking for interesting stories from the world of paragliding. Just send an email to blugleitskontakt at gmail.com. You can subscribe to Podz-Glidz on all the usual podcast platforms. I upload a new episode every 14 days. If you don't want to wait that long, feel free to browse the archive. You'll already find well over 150 hours of interesting conversations about the world of paragliding in there. As a freelance journalist, I put a lot of time, work, and also costs into Podz-Glidz and blugleits. In order for me to continue doing this professionally, independently, and ad-free, I need your support. On my homepage blugleits.blogspot.com, there is a section called Support.
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