# New Ultralight and LSA Trainer design PAIR

Discussion in 'Aircraft Design / Aerodynamics / New Technology' started by Rienk, Aug 1, 2010.

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## What is your interest/input in such a project?

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40. ### I am God's gift to the aviation design community, and should be heading up this project :)

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1. Aug 11, 2010

### Rienk

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I’ll take a look (it won’t open right now).
I finally disagree with you – though not much 
Although I agree that it is important to design for your target market, there are too many constraints in the 103 to be able to do so.
And your point about the BD-5 is kind of silly… it was designed to look “cool” because they were going after the larger audience – do you realize that almost all of the deposits came from non-pilots? Looking cool and being low cost is exactly what we’re trying to do; the only question is, who does it look cool to?

I agree that with the current 103 rules, the aircraft will have to look more traditional. I’m also starting to lean toward the fact that these two aircraft shold not be the “end all” in this marketing strategy, but that LSA and/or experimental designs will need to fill that void. I am going that route with the Solo and Duet, but something like Orion’s Rasp would seem to be quite the carrot for a lot of people.
Since a 103UL virtually must be rag and tube, it will be hard not to get it to look like a Cub – unless it is a low wing, which I favor… the problem is getting into the cockpit with rag and tube. This is usually alleviated by going with a pusher design, which I’m open to, but then the design choice is single or twin boom.

I appreciate your zeal for the goal of getting exponentially more people into flying (and maybe even selling lots of planes , but I get the impression that you still haven’t fully learned the lesson that we MUST design for production. As we consider what the new “cool” look might be, we must ignore any/all design ideas that blow away the 103UL and/or cost factors.

I am starting to hone in on two options; all wood tractor design, or a pod and boom with a plastic rotocast cockpit pod – with external features built in (wing root fairing, wheel wells, whatever). The latter may be too heavy, but would lend itself well to the two seater… which raises the question – do the UL and the LSA share the same planform or not?

There are a LOT of engineering/design questions that have to be considered while pursuing the marketing goal.
RA

2. Aug 11, 2010

### Dana

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I don't know. The ZJ Viera isn't rag and tube, and it's (IMHO) gorgeous, except for the frightfully ugly engine mount... which needs only a conventional landing gear to eliminate. There are a host of other ways to make a 103 legal airplane. Doug Hart claimed his Zipster biplane was legal, and while I doubt it, it still might be possible (though perhaps not affordable) to make an attractive light biplane. The Mitchell Wing ultralight is hardly conventional, and the Kolbs (some of which are ultralights) certainly don't look like Cubs.

If you target market is young people, some contortions getting into the cockpit aren't as big a deal as it would be with older pilots... but getting into the front seat of a Cub isn't all that easy, either!

-Dana

Always keep clothes and weapons where you can find them in the dark.

3. Aug 11, 2010

### Rienk

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Excellent points Dana.

However, the Viera is very limited as to its load parameters, and to handle more useful load and a four-stroke engine, such a design would be very difficult to meet 103 weight specs.
Secondly, as much as our target market might consider a "ride ON" airplane to be "cool", the practical limitations of it would soon wear thin. Most of my 'research' has shown that a "ride IN" aircraft is the correct choice. This is especially true if the aircraft will be used for mild racing or aerobatics. It could still be open cockpit, just not a straddled seat (which offers terrible crash protection).

As I've posted before, we have much of the initial design of an 'upgraded' Viera already done (I might even be able to dig up some of the 3D files). We ended up moving to the Solo design because it gave so much more performance for very little extra cost (as a comparison, the Viera is more expensive than the Solo will be).

A biplane is difficult to get the wing efficiency needed, especially with low power, and is generally terrible for visibility (though it can help in crash protection).

A flying wing is a great possibility - but I have no experience with them. If Orion or someone else qualified would provide the design - i would build it. I love the Rasp concept. I have also talked with Jim Marske about this.

Pod and boom UL aircraft are fairly common, and is the other solution I recommend. Kolb, Earthstar and others have legitimate designs - the issue is getting the cost down and the sales volume up.

Regarding the cockpit access issue: I was not specifically referring to the contortions needed, though that is an issue. I was more concerned about having to add structure (and thus weight) to be able to climb in without destroying wing skin, etc - especially in training craft.

Frankly, I don't think that young people will care as much about the layout as the price.
Yes, they would probably prefer a "cool" design over a traditional design (this is hard to determine). But the other important MARKETING issue is, "Yes, I would feel safe flying in that." Remember, we are not after the daredevils, but rather the adventurous AND their friends!

A traditional design also best meets one of the other imposed constraints - portability. It would be nice to be able to fit two of these units in a small trailer (most people usually enjoy motorsports in at least pairs). A single boom design could do this, a twin boom probably cannot.

IMO, there are three aspects to this that must be considered together (not one before the other).

• Marketability
• Manufacture-ability
• 103UL regs

If it helps, I'd be perfectly willing to sponsor a design competition, with the winning design getting a cash prize and a royalty from sales.
Would there be any takers?

The reason for this thread was that I thought it would be better if this were a collaborative effort that actually went somewhere, rather than a competition that might result in a lot of designs that never get built.

Last edited: Aug 11, 2010
4. Apr 4, 2011

### buzzypeterson

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It can be done for 10k. as far as putting ribs together it doesn't take much skill to make wood ribs. I would think you could find a few retired folks that enjoy woodwork give them a jig, capstrips, t88, and a handsaw and there you have your ribs taken care of. Otherwise aluminum ribs stamped out is the way to go, it worked on the cub right?

As far as a spar, i'm building a double eagle and am kicking around what i'm going to do. It uses a ladder construction that is very easily built though.

Don't mess with what works. There is a reason why steel tube construction is so common. Fabric is also a must. I have to disagree with the others about fabric. A fabric plane can look like a real plane. When people find out that my current plane is fabric they are always suprised because it looks like a real airplane until you touch it.

As far as cover and paint it's a job for 3M glue and house paint. And with the engine I think the continental 4A-084 for the 2 seat and the 2A-042 for the ultralight. Otherwise whats wrong with sticking to the VW? It's inexpensive and easy to work on. Why must it be ultralight? why can't you have both be ELSA? what is your reasoning that one of them has to be part 103? If you could have the same wing and work with a bunch of different configurations you would be doing a smart thing. Look at piper and aeronca and how they used the same wing materials for a bunch of different planes.

Anyway that's my 2 cents

5. Aug 17, 2011

### Tom Nalevanko

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Whatever happened to Rienk and his aviation efforts? Anyone see him exhibiting at Oshkosh?

6. Aug 17, 2011

### Hot Wings

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7. Nov 7, 2012

### Detego

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Still looking for Rienk?

8. Jul 26, 2013

### Rienk

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Hey guys, I'm back - don't know if ya'll are still here and interested?
Aviation hobbies had to be put on the back, back burner for a while, trying to stay solvent. We're getting back on our feet again, and starting to have a little "mad" money available for this nasty airplane addiction.

I actually forgot about this thread, and started picking up the train of thought on my "Tehachapi" motorglider thread - but this is really the place for my thoughts, so I'll try to redirect my conversation this way (for anyone still interested in this topic, reading the latest few pages of that thread might be beneficial).

The Solo and Duet projects are still going to be my primary focus, but as usual, my ADD/autism have me bouncing all over the place - so hopefully I can squeeze this pair of projects into the mix... I certainly can continue the conceptual and design process!

Any new developments or ideas along these lines that I should know about?

9. Jul 26, 2013

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