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Dana

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In the very early days of hang gliders, before Part 103 (when few if any got out of ground effect and the rule was "don't fly higher than you're willing to fall"), the FAA was threatening to fine anybody who left the ground at all. Anything that left the ground at all was considered an aircraft. The organizers of the first Lilienthal Meet even went so far as to keep their identies and the location of the meet secret, lest the Feds show up.

-Dana

Giving money and power to government is like giving whiskey and car keys to teenage boys.
 

orion

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I think the difference here is that WIGs uniquely operate over the water. Back in the mid eighties, when asked whether the FAA considered this a fish or a duck, the official response was that they didn't want to touch the issue with a ten foot pole. I think that still holds today.

But since operation will be mostly over water and tidelands, the FAA seems to be more comfortable leaving these alone and keeping them under the marine vehicle definition.
 

lr27

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I thought ground effect was supposed to be significant when within a span (or was that a half span?) of the surface.
 

Peter V

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Here's the most ultralight thing on water. It's a control wing, so the fusalage is always level and it sits on a pair of surfboards. Like a mosquito on water. It doesn't displace.

 

Topaz

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Wow. That "tail" sure looks like it's being blanketed by the pilot - a LOT.

And yet the website shows a landplane version of it flying.

Odd.
 

Peter V

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It's still under development. The photo is misleading. Here's the land based version:


I believe that the seaplane version will require more power than it was tested with (25hp)

I definately want to build one, based on its looks, cost and the fact that a control wing makes a lot more sense than a fixed wing.
 

WileEZ

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Very interesting indeed!

I'm wondering though, if the control wings is so good, how come we don't see more designs using the control wings concept?
 

Topaz

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I can't speak to the overall concept (don't know enough about it), but the fact that George Spratt offered the original ControlWing plans/kit in a pure flying-boat (not amphibious) form probably didn't do much for the adoption of the concept more broadly. I think he may also have done a landplane version first (fuzzy memory of a tri-gear two- or four-seater), but the only thing I saw generally marketed "back in the day" was the little 'Spratt Controlwing' flying boat.

Neat little machine, it was, but not many people can operate ONLY from the water.
 

Peter V

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There would be a few factors.
Firstly mounting your wings on a single pivot would involve prohibative stresses for any sizable aircraft.
Also, it would be a bore to fly recreationally. No aerobatic ability at all.
Another problem is getting the engineering right.

But the benefits are numerous. The thing can't stall. You're always level, wind gusts are absorbed by the wings. Actually, it's easier to think of it as a 'hard' powered parachute, than a regular aircraft.

Legend has it that the design was meant to be tested by the Wright brothers, it's that old, but the prototype was destroyed in a storm. Lately it's been adopted in a military drone design because of it's stability.
 

Dana

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The controlwing desing has a tainted history... Henri Mignet's Pou du Ciel (Flying Flea) of the 1930's was the same concept. After numerous accidents caused by an early design flaw, the concept fell out of favor and although the problem was eventually resolved, its image never really recovered.

Also being a 2-axis control design, it doesn't handle crosswinds well.

-Dana

The Bill of Rights goes too far--it should have stopped at "Congress shall make no law".
 

Norman

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Mignet’s problem was due to the TE of the moveable wing getting too close to the aft wing and creating constructive interference I.e. “slot effect”. Obviously that can’t happen to a monoplane
 

Aerohydro

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Hello Everyone,

Long time lingerer, and first time poster. I'm pleased to say that through some random luck, I've been able to ID this machine. This is the Apteroid, designed and built by Vern Siefert in the 1960s.

A contemporary article about it can be found here: "Popular Mechanics" - November 1966 - page 117

An article had also appeared in EAA "Sports Aviation" - May 1967, but unfortunately I don't have access to that.

Vern Siefert died quite recently - 2019 - and in this memorial page to him, it's mentioned that he "... looked to nature for inspiration for his unconventional aircraft designs. He flew a Piper J-3 modified to mimic a gyrfalcon, complete with pivoting wingtips." It's the Apteroid that's being referred to here; the name being the term used for a wing that is longer than it is wide, such as when a bird dives at high speed, and tucks its wings in close to its body. Looking at these b&w images, you can see how the Piper J-3 had been reused within this flying machine. The main undercarriage wheels and struttage are there, however the tailwheel has been repositioned in order to now act as the nose wheel. One half of the original tailplane now serves as the fin and rudder.

Comparing the colour photos in the original post (and which probably date to the 70s or 80s, rather than to the 50s), to these earlier b&w images, it's clear that the Apteroid had a rough life. Virtually every part of it seems to have been replaced and revised. Most notably, and bizarrely, the entire wing has been turned upside-down! This can be seen when looking at the second of the three colour photos, where the writing on the wing tip turns out to be the registration N-4242, except that it's inverted.

Cheers,
Paul
 

BBerson

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Welcome to the forum.
I knew Vern Seifert for years and talked about his ideas. His modified L-2 had bumps on the wings like the wing flippers on big whales. The L-2 had house carpet on the top of the wings for boundary layer control tests.
 
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Sockmonkey

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Barny Wainfan, in an early article about his Facetmobile, mentioned some early (1930s?) NACA studies on very low aspect ratio aircraft. It seems that as aspect ratio decreases, wing efficiency decreases...to a point, then improves at even lower aspect ratio. This apparently because the vortex from each tip, as it rolls up, is countered or opposed by the vortex from the other wing. Low aspect ratio wings would have all sorts of advantages and weight savings. An inflatable plane would be a lot easier, with transport and storage as major benefits.
At what ratio does it start to improve? 1-1?
 

Sockmonkey

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Zimmerman said the “magic” aspect ratio was 1.27 ( the aspect ratio of a circle). David Rowe reported his 12’ span UFO had about the same power off glide as a Drifter - would help to explain that phenomenon.
Thank you. I guess that's why Scroggs' "Last Laugh" flew better than it looked.
 

WINGITIS

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Welcome to the forum.
I knew Vern Seifert for years and talked about his ideas. His modified L-2 had bumps on the wings like the wing flippers on big whales. The L-2 had house carpet on the top of the wings for boundary layer control tests.
"House carpet" aside from the weight it may bear some thinking about!?
 
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