Saturday, March 28, 2020

Interview Michael Nesler

Hi,
In those difficult times, I'm trying to send glider designers some questions in order to give you a more comfortable way to spend the time at home. Here's is a very interesting interview with Michael Nesler.
I knew about Michael Nesler's designs since I began to learn paragliding. He is from the “golden era”
His exceptional profile!
https://profly.org/Nesler/?fbclid=IwAR2BWVXaBxlExeTXrozwoC
( Click personal)


Dear Michael,
At first, I hope that you and your family are doing ok! The conditions in Italy are critical, and hats off to the Italian doctors, nurses and everyone involved…God be with you all!
Thank you for taking the time to answer my questions.

Ziad: I have flown your designs recently. Let's take for example the Nyos RS EN-B.  It doesn’t have a shark nose, or the back positioning A’s, the lines are not that thin as some high B competitors, but it seems to glide as good as the best!  In your opinion for the moment, is positioning the A’s far back, for a high B is a must for selling? or there’s some benefit in that category in cutting through the airmass? Will this work for a B? Knowing that the latest Ozone R5 doesn’t seem to have the shark nose of the older models.

Michael: What ultimately determines the performance of a paraglider is very complex. Let me give you an example: If I have the Nyos RS made in China, it will fly like the one you've been flying. If I have it built in our factory in Croatia with the same files and materials, it will fly much better.
According to the experience of the last years, the dependency of performance is roughly distributed like this:
* 35% project
* 25% material
* 40% manufacturing quality (cutting, sewing, control)[/i]
Of course, the media and customers get off on technical, tangible details such as shark nose, A-loops, etc., but precision is much more important.
The fact that the Shark-Nose cost performance has meanwhile been accepted by other manufacturers. That's why they still install the rods crossed at the opening, but when you look at the profile shape without opening, there is little left of real Shark-nose.
In summary: If you could make any model you wanted with better materials, individual cuts, and very good sewers, it would be vastly superior to mass production. But no manufacturer can afford that.
The position of the A-Loops is not important for performance, only for safety and durability. And this is contrary to each other: Either more safety and shorter service life - or vice versa!



Ziad: I’m impressed! I never knew that it would differ that much! There are companies in Srilanka doing a clean job on paragliders. Do you still think that if it's done in Croatia or should I say in a more delicate and precise way it would fly better? How better please? What are those differences?

Michael: No, factories in Srilanka, China and other places are doing a clean job for economical serial production. But they are far away from the maximum possible.

Ziad: You said earlier that they can't afford that?  why? Can you comment, please?

Michael: Simple to calculate: Cutting 16 layers (8 gliders) on rotating knife cutter or high power laser needs nearly 8 hours = 1 hour/glider. If you make a single cut with high precision, you need also 8 hours = I glider!
A good sewer needs 30-40% more time to finish a perfect wing. So in the end, the glider will cost, also using the best material, quality control, individual trimming, ca. 60-80% more. Nobody will pay for this!


Ziad: You also said: On a competition glider, no one will use a shark nose if its cost performance! The Enzo 3 and B11 use it. What are your thoughts, please?

Michael: They are far away from real Sharknose: if you don't watch the crossed ends of the rod in the vent, but the real shape of the profile, you will see that there is nearly no shark-nose anymore! Only simulating a step on the vents you don't get a real shark-nose: te vent area is filled with a compressed air cushion!


Ziad: There are lots of nice ideas for designing paragliders. I always wondered if we put all them together in one glider, would that be beneficial? Some could be for marketing purposes, but some works quite well… I mean for all the classes, probably a shark nose, RAST, a 3D clean leading edge, and all the internal technologies, optimized unsheathed lines, etc, etc…  or there’s something that today's designers cannot overcome.

Michael: I am currently working on an EN-D two-liner, which we have both with and without a shark nose. In the lower speed range of the certification, the Sharknose doesn't make sense, it just causes disadvantages.
If I were given the job of building the perfect glider, I would:
- Take this material here: https://www.extremtextil.de/dyneema-composite-fabric-ct03e08-12g-qm.html (I've built a couple of base wings with this, brilliant!)
- Cut the glider individually by laser
- Glue all panels before sewing
- Accompany the sewing personally
- Use Vectran lines
The absurd thing is that such an existing model would fly better than a new, allegedly improved one of conventional design.


Ziad: Why Vectran lines?

Michael: Vectran has less elongation, is more stable during aging, am stronger. It would be perfect as main lines, also with cover. But till today nobody is producing Vectran baselines for Paragliders (with colors, coating/cover). But they are used for many years in high-performance skydiving canopies.

Ziad: What are your thoughts about a super designing tool? Will a futuristic superior software help in the design of our flying machines? Or are we still limited by the materials?

Michael: We have long been outside the reasonable tolerance with regard to production and material. It will hardly be possible to increase performance with conventional and inexpensive solutions.

Ziad: I was always fascinated by the internal structure of a glider. For example, the UP Escape had some cross reinforcements that were never been seen lately?  Is it right to believe that internal structure is the main key to performance and safety?  Are we still far in this field?

Michael: I know the Escape very well, I made it. But this construction has one main disadvantage: too much waste, too expensive!
The inner life serves only one purpose: Less lines! There is one clear limit: the strength required by the certification. Most high-performance gliders push this to the limit. So you couldn't have less lines. A highly complex inner life is interesting and light, but it is certainly not a parameter with which you can improve performance.
Unless you build gliders with over 100 cells, they would become too heavy without 4 or 5 cell spacing.

Ziad: What are the benefits of using very light construction of RAST on a 7 AR 2 liner glider? I think you surely thought of that!

Michael: I have been flying it for 3 months now and it feels like an EN-B paraglider to me. I fly it here in the Dolomites in conditions where others prefer to stay on the ground with the B-gliders, and I feel comfortable. What I miss is better take-off behavior in snow and tailwind and big ears.
But I have now found a solution for this, including certification without folding lines.


Ziad: What are your future projects? Any new harnesses? certification for the 2 liner?

Michael: I am working on a harness for pilots who like to fly very precisely with weight and want to be a perfect unit with their equipment.  This will be a niche product: Ultralight, high strength (with Kevlar fabric and Dyneema), with seat board and no cross bracing. So completely against the mainstream. This is not a Swing order, but a Profly project.
EN-D is in work and should be approved according to Corona.


Ziad: What do you think about seat and seat-less harnesses? Rear fairing or not?  Which do you think is more appropriate to your liking?

Michael: We have several harnesses here for testing our gliders. And have found that flight behavior, performance, and safety are more influenced by the different harnesses than by the trimming.
I am surprised that the manufacturers of harnesses do not even adhere to the requirements of the certification regarding the height of the main suspension. Most of the current harnesses have a much higher main suspension than the certification requires. In addition, the newer harnesses are being cross-braced more and more. This allows weaker pilots to fly with higher classified gliders, but it reduces performance significantly compared to flying a simpler glider with a good harness.
In all comparisons, I still find the old Woody Valley GTO-Xalps Race (2.2kg, with a board) the best for me.


Ziad: what if we were all flying the same model and there were no other models?

Michael: Then no one would be able to blame the material for bad flights, no one would be able to boast of being an unpaid brand ambassador, and no one would be the hero anymore for flying such a great, dangerous glider.
Ziad: Would this be less fun then?

Michael: Let's face it: the whole discussion about performance is only needed by the manufacturers, the salespeople, and the media. After all, what else would they be able to captivate us, pilots, with?
I still like to build high-performance machines on commission, but nobody really needs them.
Most pilots would be better advised to work on their technique, perception, and psyche instead of constantly stunning themselves with new material.


Ziad: You mean like one design glider for "Olympic games"? But that will also be branded somehow...
Michael: Here we have been shortsighted! If we got a one-design class for competition (ok, different brand, but very strict parameters like in sailing or formula one) we would be since many years in the Olympics! The same model means, that the results come from the pilots and not form the glider (and the money to buy always the best wing)


Ziad: A message for the pilots staying at home?

Michael: This is a good time to start thinking about flying:
* Why am I flying?
* What's in it for me?
* What would give me more performance?
* What are my goals and wishes when I fly?
It is best to write (on real paper!) because this keeps all-important channels of perception involved (sight, hearing, touch).

Thank you very much for your time!

Best regards,
Ziad



PS: Every designer has his own perception and futuristic ideas. The above interview was made to show a different and interesting point of view.
IMHO, the best glider you seek is the one that makes you feel good, and that special 'you' is a very personal matter Smile
Stay safe!
Ziad


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