Discussion: Conceptual Design of an "Inexpensive" Single-Seat Motorglider

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Rienk

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Well, if you ever decide that with the fixed gear, you end up making it a pod and boom pusher - a la Strojnik - I would definitely consider helping you build it (though then we'd actually build molds to put it into production!)
 

Topaz

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Wow. That's an incredibly generous offer! May I ask what's behind the desire to to a pod-and-boom pusher? I mean, it obviously worked for Strojnik, but I'm curious about your interest.
 

Topaz

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While I appreciate the suggestion on the Atos Wing, and I really like that little 'plane, but I'd like to keep this thread focused on my own design. Which needs to have some updates posted, I agree. Thanks.
 

Speedboat100

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Topaz..can we see these updates ?

I think the Pipistrel Sinus and Alpha are showing that affordable aviation in electrics is also the safest when you fly a motorized glider type aeroplane.
 

Speedboat100

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All these discussions of cardboard, paper, and so on are nice on their face, but you can't simply focus on the one point-use-case of the impact itself. Any impact attenuator solution has to remain effective and intact for the lifetime of the aircraft, or at least through a reasonable service interval.

Humidity, spilled drinks, and getting out of the cockpit in a rain-shower are all ways that a cardboard/paper attenuator can be degraded by getting wet. We also tend to step on aircraft seats during normal ingress/egress of smaller airplanes, and that puts off-center point loads on the attenuator, meaning likely to break it down even further. This latter is also an issue with foams, honeycomb, etc.

After reading various resources, I'm more and more convinced that mounting the seat on a set of beams (S-beam or even simple straight ones) that yield under the necessary impact loading is the way to go. The results are predictable, consistent, and the system is really enduring in day-to-day use, simple, and made of inexpensive materials.
How about using plywood..it is very strong and yet lite material....and can be treated to withstand the weather. Also very inexpensive.
 
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Topaz

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Topaz..can we see these updates ?

I think the Pipistrel Sinus and Alpha are showing that affordable aviation in electrics is also the safest when you fly a motorized glider type aeroplane.
Yeah, "I need to post some updates." Back in February. >sigh<

I'll go over to the main thread and post an update. I'm afraid it's not going to be much of an update, but I'll post what I can.

Regarding electrics, I agree that electric propulsion is the future, and for a pure self-launching sailplane, I might even be tempted to try that now. But this project has a component of powered cross-country flight, and that's still "bleeding edge" enough for electric propulsion in the homebuilt arena that it's more than I want to take on for my first build project.
 

Topaz

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Doran Jaffas

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Off topic...sort of. I agree with aircraft plywood being very viable, light weight and extremely long lasting when waterproofed, glued and treated with a UV protection system. I own and fly a Wittman Tailwind W8. The wing is entirely made of wood with ceconite covering and treated appropriately however the Tailwind is definitely not a glider
 

PiperCruisin

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Hi Topaz,
Why are you designing it to be LSA versus simply experimental? I'm not sold on either one, just curious the reasoning.

Glad to see you back to working on it. Kind of been watching yours, the Robin, and the JT-8/JT-10.
 

Topaz

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Hi Topaz,
Why are you designing it to be LSA versus simply experimental? I'm not sold on either one, just curious the reasoning....
Very simple, and purely selfish: Once the madness in my life settles down a little, I'm going to be picking up my Sport Pilot certificate. Flying gliders is fun, challenging, and "different," but they're not usable for cross-country flights under power without a self-launch endorsement. I could get the latter somewhat less expensively than getting a Sport Pilot certificate, but the Sport Pilot cert offers me a much broader spectrum of aircraft to fly, and that was the deciding factor since I'll be renting until I finally get something of my own into the air. I have some medical issues that, while they don't interfere or make me unsafe while flying, would require a special issuance for adding an ASEL rating, and I don't want the annual mound of testing and paperwork it would require. I definitely don't want that Sword of Damocles hanging over my flying all the time, especially for the purely recreational type of flying I do and will be doing.

Being pedantic about it, my design is E-AB, and qualifies as an LSA. A Private Pilot ASEL could fly it, as could someone with a Private Pilot Glider cert. Or someone with just a Sport Pilot. Making it compliant with LSA fits my own needs, and opens it up to more people to be able to fly it.
 
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Topaz

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Thank you, but no. I've already decided on my engine. I don't need - nor want - a 40hp engine. I appreciate everyone's opinion as expressed in the various industrial engine threads, but I'm going my own way.

Also, I thought the "Member Project Logs" threads were locked? @admin , is that no longer the case? I would appreciate it if all questions, comments, and input for my motorglider project be confined to the discussion thread, here: https://www.homebuiltairplanes.com/forums/threads/discussion-conceptual-design-of-an-inexpensive-single-seat-motorglider.19740/
 

Victor Bravo

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It is my understanding that LSA and Sport Pilot is going to be changed around pretty soon, to the point where the Sport Pilot license would cover something up in the Cessna 182 class. So make sure you keep abreast of those winds of change, and don't paint yourself into any corners with the design just yet.

You also have access to a particularly old, dusty C-172 for training if you need it, and access to it's particularly old, dusty owner for non-CFI flying practice whenever appropriate.
 

Topaz

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It is my understanding that LSA and Sport Pilot is going to be changed around pretty soon, to the point where the Sport Pilot license would cover something up in the Cessna 182 class. So make sure you keep abreast of those winds of change, and don't paint yourself into any corners with the design just yet.
I've been away from the "scene" for a while now, but I know of nothing but some vague rumors that a lot of people want the LSA and Sport Pilot rule to be "bumped up" to larger, more-powerful aircraft, but I've seen nothing to substantiate that the FAA is even considering this. Have I missed a link here or somewhere, to which you might be able to point me?

In terms of my project, the only way LSA impinges on it, really, is whether or not the main landing gear is retractable. The rest of it just happens to be LSA-compliant, because the numbers I want (and can get, with this powerplant) happen to fall within those boundaries. Even if LSA were to stand exactly the way it is now, I don't think anything on my project would change. I think I can have a retractable mono-wheel main gear on a powered-glider LSA because if a "powered glider" is considered a "glider" in Part 23 and Part 91 (no medical required, no extra training or rating for retractable landing gear), then the same thinking ought to apply to LSA. My design is most definitely a "powered glider", by any reasonable definition, so I'm thinking this should be okay. Of course, it'll be up to the local FSDO to make that determination. I'll talk with them before the build begins.

You also have access to a particularly old, dusty C-172 for training if you need it, and access to it's particularly old, dusty owner for non-CFI flying practice whenever appropriate.
You sir, are a most generous and kind fellow. We'll talk.
 

fly2kads

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I've been away from the "scene" for a while now, but I know of nothing but some vague rumors that a lot of people want the LSA and Sport Pilot rule to be "bumped up" to larger, more-powerful aircraft, but I've seen nothing to substantiate that the FAA is even considering this. Have I missed a link here or somewhere, to which you might be able to point me?
The recently departed acting FAA Administrator addressed this at AirVenture. Not surprisingly, details and schedule are still squishy at this point.
https://www.eaa.org/eaa/news-and-publications/eaa-news-and-aviation-news/news/08-08-2019-MOSAIC-Rulemaking-Package-Detailed-by-FAA-Administrator
https://www.bydanjohnson.com/latest-update-on-faas-plan-to-change-light-sport-aircraft-regulations-july-2019/
 
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