StarJar
Well-Known Member
This may be a rambling querry, roughly based on the airplanes in the pictures. They are the Thalman T-3, and T-4. The T-3 had about 40 HP. The fuselages, and cantilever wings. were built with geodetic construction.
Several things are intrigueing about these aircraft, to me, even though there is little information on them. I can only find a few picturest on the internet. (I think there is a Sport Aviation article on them, but I was uanble to access it.)
An interesting thing, besides the fact that the wings are cantilevered, is the taper ratio of the wings. I'm not very knowlegeable about airplanes of that time, (early 1940's) but it seems that high taper ratios were common. I'm not sure why this was, since apparently rectangular (Hershy bar) wings are just about as efficicient.
This could be a large debate, especially since we have many glider pilots among us, on HBA, but I'm referring to lower end, powered aircraft. The thinking is that, for a given wing area, a non tapered wing 'does it' with less span (among other things). But I'm open to debate, on it.
These planes had extreme taper ratios (it appears). Just wondering if anyone might know why. Another intersting thing is; If the geodetic construction could make such long, tapered, wings workable, wouldn't this method be great for shorter, 'Hershey bar", cantilevered wings, like on an ultralight? Yet I don't see any. Fisher Flying Products have geodetic bracing, but not a cantilevered wing.
There is an is an HBA resource download, Geodetic Aircraft Structure and Geodetic Aircraft Structures. Part Two, that show more about geodetic construction, with some explanations of how it works, and how it's used. The above link also shows how really curvy fuselages can be made, with this light-weight technique. When I saw this, I started thinking, "mid-wing", since the rounded bottom of the fuselage, is nice asthetically, but not conducive to mounting a low wing.
The only thing is, one might need a large root-cord, to put the main-spar in front of the instrument panel. The rear-spar could go behind the seat-back.
Any comments, ideas, or further information on any of the above quandries would be welcome, and perhaps interesting.
Thanks, SJ
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