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Does this aircraft have any use?

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bmcj

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If that is a real proposal, it looks as if it were designed to mimic bird aerodynamics (for instance, the feathers at the wingtips).
 

Aerowerx

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I don't remember the details, but there have been some research into using multiple winglets at the tips.

It looks like a Turkey Vulture, so should be good for sustained soaring and tight circles in a thermal.
 

Vigilant1

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Any use? Maybe as a small UAV that can remain circling over a target for extended periods without drawing suspicion?
If it becomes popular, I'd expect a negative impact on the the population of hawks, etc, especially over locations where illicit activity occurs or privacy is valued.
 

Riggerrob

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To truly work efficiently, each "feather" needs to pivot independently .... something birds learned a few million years ago, but humans are still struggling to learn
 

proppastie

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have a friend that has a RC bird looking plane that he uses to scare starlings. It looks something like Post 1 and its use is to scare birds away from gardens and airports.
 

nestofdragons

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This kind of airplane was always of my interest. Marko Stamenovic made a study about this type of wingplatform for me.

It was my intend to create a hangglider that was easy to assemble. Just a rigid structure you can transport on top of your car. At launchpoint just slide in the wingtip feathers and add the tail and take off. Marko did many many calculations and was really surprized with the stability at low speeds of this concept.
2013-05-21 The Bird Glider AA AB_500x359.jpg
2013-05-21 The Bird Glider AA AA_500x320.jpg
The project evolved into the BirdGlider which was a more classic concept. Reason was mostly our concern how to fix pilot into this glider.

What did i learn from this project? Short coupled airplanes are possible, but ... when i tried to present BirdGlider at AeroShow i noticed that people are very very doubtfull about the short coupled tail. they did not trust it. I guess only positive test results would make them change their point of view.
Stability would have been the surprising benefit of the concept. And i guess beginner-pilots need that stability. So it would have been a good glider for beginners in aviation.

Tha sad part of this project is that Marko had a PC crash and all the data was lost. All i have are the rough 3D's which were the start of the idea. At that moment we had no clue of the real dimensions of the wing and tail. By tha way ... Marko insisted on also placing a vertical tail for stability. Marko is now working on flying plank designs without vertical tails. He uses the Horten way of wing design. Bell shaped lift distribution. Maybe he could with his knowledge now create this glider again but without the vertical tail.

The Birdlike BirdGlider project can be seen here: The Bird Glider - Nest of Dragons
My opinion about the wingtipfeathers can be seen here: BirdWing - Nest of Dragons

I still believe it could be a fun hangglider for beginner pilots.

Keep that brain spawning wings,
Koen Van de Kerckhove
Koen is pronounced as racoon without ra ;)
 

Aerowerx

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Keep in mind that birds do not have vertical tails. Their lateral stability is entirely from the details of the wing shape.

And the horizontal tails on birds are a control surface, not for stability. This has been discussed before here on HBA.

I refer you to Al Bower's paper on flying wings, where he asks the question "why don't birds have tails". Highly technical to start, but scroll down to document page 12.
 

crusty old aviator

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I was half-expecting to see this picture:
1592313647680.png
They have great STOL performance, but then what? Cross country flying is like forever going no where. They do teach the builder sheetmetal skills and systems installation, like an apprenticeship for building an RV, except the rivets on this bird are popped, not bucked. So I guess it does have some use...
 

jedi

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Sahuarita Arizona, Renton Washington, USA
This kind of airplane was always of my interest. Marko Stamenovic made a study about this type of wingplatform for me.

It was my intend to create a hangglider that was easy to assemble. Just a rigid structure you can transport on top of your car. At launchpoint just slide in the wingtip feathers and add the tail and take off. Marko did many many calculations and was really surprized with the stability at low speeds of this concept.
View attachment 98074
View attachment 98073
The project evolved into the BirdGlider which was a more classic concept. Reason was mostly our concern how to fix pilot into this glider.

What did i learn from this project? Short coupled airplanes are possible, but ... when i tried to present BirdGlider at AeroShow i noticed that people are very very doubtfull about the short coupled tail. they did not trust it. I guess only positive test results would make them change their point of view.
Stability would have been the surprising benefit of the concept. And i guess beginner-pilots need that stability. So it would have been a good glider for beginners in aviation.

Tha sad part of this project is that Marko had a PC crash and all the data was lost. All i have are the rough 3D's which were the start of the idea. At that moment we had no clue of the real dimensions of the wing and tail. By tha way ... Marko insisted on also placing a vertical tail for stability. Marko is now working on flying plank designs without vertical tails. He uses the Horten way of wing design. Bell shaped lift distribution. Maybe he could with his knowledge now create this glider again but without the vertical tail.

The Birdlike BirdGlider project can be seen here: The Bird Glider - Nest of Dragons
My opinion about the wingtipfeathers can be seen here: BirdWing - Nest of Dragons

I still believe it could be a fun hangglider for beginner pilots.

Keep that brain spawning wings,
Koen Van de Kerckhove
Koen is pronounced as racoon without ra ;)
Thanks for post # 11 although many people say they just want a slow, simple inexpensive aircraft when it comes down to it their real interest is in going somewhere and speed does become an issue. Typical soaring birds, condors, eagles, and vultures need to hang out looking for food. Many pilots get board just hanging out and decide they really do want to go some other place to eat and gravitate towards aircraft configurations more in line with seabirds such as gulls and albatross. This thread was started because I am having difficulty finding good reasons to develop the floater vulture like configuration of the original post.

Original post history:

I have been looking at several design studies along the lines of the proposals of

What is an affordable ultralight?

and as a result I sketched out the glider plan form of post #1 above and the specifications listed below.

Specifications:

Length 12 Ft 10 In

Span 30 Ft (9.2 M)

Cord 5 Ft (1.5 M)

Wing Area 150 Sq Ft (13..8 Sq M)

Aspect Ratio 6:1

Replaceable flight feathers 9 Feet 6 inches (290 cm) long by 21.6 inch (55 cm) inch cord.

Replaceable tail feathers 5 Feet 7 inches (170 cm) long by 21.6 inch (55 cm) inch cord.

USA FAR 103 compliant as a glider or possible motorglider.

Estimated glider performanace minimum sink 3.5 ft / sec. L/D 10:1 at 35 mph.

Estimated motorglider performance Vso 24 kts (45 kph) Max cruise 54 kts (100 kph)

The aircraft incorporates replaceable/disposable wing tips and tail “feathers” that are in development for another configuration. This configuration was intended to be a basic application for component development. It would utilize multiple units of three feather component part numbers. The proposed design incorporates 7 identical tail feathers and 4 each of identical left and right flight feathers. The use of multiple identical replaceable/disposable parts per airframe would permit relatively high volume low cost construction and owner/operator maintenance procedures.

As part of a design review the question of mission specifications and target market were asked. The design would for optimized for low minimum sink rate and low power and for low altitude operations. I do not see much market demand for the proposed specification. Therefore the original post was started.

Background:

Soaring birds and to some extent most bird species can be divided into sub groups by wing planform. Some birds have a typical tapered wing plan form with a relatively narrow wing tip. Other birds have a much more rectangular wing shape with a wing grid type of wingtip. This charistic tends to apply to both soaring birds as well as the more common species that rarely soar such as pigeons and starlings versus jays and crows. The extreme of these two branches is represented by the Wandering Albatross and the Condor, one that has a very high aspect ratio optimized for maximum L/D and the other that has a much lower aspect ratio optimized for minimum sink.

The vast majority of the soaring community is involved with the albatross design (pun intended). A small minority of modern soaring designs are optimized for minimum sink. I attribute this to the current soaring contest emphasizing speed and distance rather than flight in minimum strength soaring conditions.

Aircraft Examples:

The many typical high performance glass and carbon composite sailplanes built for the last 20 or more years are examples of the albatross high aspect ratio wings.

The 1930’s era primary gliders and the more recent Zigalo, Goat, Air Chair, EMG-6 and other basic gliders represent the low aspect ratio wings but have a limited popularity in spite of their relative low cost.

Any more comments?
 
Last edited:

John.Roo

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Oct 8, 2013
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Letohrad / Czech Republic
I saw on web this design...
1592373533052.png
OK - I know that this is a RC model :)
But looks that is flying nice.
It could combine tested and not expensive technology (hang glider), reasonable performance and possibility of easy transport.

I am not expert for hang gliders, maybe that propulsion position makes no sense in case it is controlled by CG (seems that the model has ailerons).
Till now I saw only this position:
1592374220062.png
Or "normal" trike.

I mentioned hang gliders because of pricing (request for simple and affordable construction) + I am affraid that 10:1 is a bit too low L/D. Is aproaching to paragliders (8:1).

Best regards!
Martin
 
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