Flying wing as cheap and simple option for basic fun flying.

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EzyBuildWing

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Sep 23, 2009
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Sydney NSW Australia
Cheap basic fun-flying?.....how about an all wood Cri Cri cinfigured as a tri-motor ???
Just like building a large conventional RC-model.....fits easily in your living room.
Recent Youtube vid from Culver-propellers shows how to glue timber-propeller laminations together. Same deal....easy!
You can see a tri-motor configuration ultralight if you scroll down this page:

Ultralight Plane Engine
 

Riggerrob

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Canada
www.atusdesign.com has a summary of inflatable airplanes, including the early work by Daniel Perkins, in Britain during the 1950s.
HistoricWings also has an article on Daniel Perkins inflatable flying wings.
bayourenassanceman.blogspot also has an article on inflatable airplanes including some 1930s experiments by a Russian.

I have long thought that an inflatable delta would be a great fun flyer that stored away in a tiny space.
Hint: I am sometimes seen paddling my Advanced Elements inflatable kayak near Vanocuver.
 

rotax618

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Evans Head Australia
A low aspect flying wing would be the obvious choice for an inflatable aircraft. I think that most attempts at constructing an inflatable wing have had only moderate success because they have tried to make all of the wing inflatable, when if the main bending loads (spar) could be taken by a conventional beam (maybe foldable) and only the rib and skin loads taken by an inflatable envelope the design would be less challenging.
 

Sockmonkey

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Erkki, the little high wing that you put in post #1957 will be nearly un-controllable on the ground. An aircraft of this configuration will need to be a conventional nose-gear design, not a taildragger.

Sockmonkey, would you be kind enough to move the main gear back a ways, and put a little nosewheel at the front of the pilot pod? If the world can't keep Erkki's boundless enthusiasm below nuclear fission levels, at least we can give him half a chance to keep the airplane on the runway :)

However, there is still a potential danger in this configuration... the thrust line is above the center of gravity, and this creates the same nose-over ("bunt") potential as they have seen in gyrocopters with a thrust line above the CG. The wing chord will have to be fairly large in proportion to the thrust line's distance above the CG.
Sure thing. I did several different configurations anyhow. Trike, taildragger, wing mounted engine, nose mounted engine, junkers flaps with endplates, folding wing design, etc etc. Also in orange with an elliptical wing and balloon tires because why not? Also in green with swept and unswept tapered wings. We have a blue trike with delta with endplates and junkers flaps, and we got a straight wing with those too. We have your sexy Little Bird clone in war paint in both straight edge and curvy versions.
At Sockmonkey's airplane rendering emporium we have what you want!











Before you go much further with Sockmonkey’s design you should build a simple foam RC model, use a common fuselage and try different wing planforms (rectangular, circular, semi-circular and elipsoid). Since the wing has a very short span a few different size ribs shouldn’t be a problem. You will most likely find as Charles Zimmerman did that the rectangular shape is the least efficient and is the least stable at high angles of attack.
As a partial solution, we can also do as Zimmerman did and make interchangeable tips that can be plugged in as an aftermarket add-on kind of thing.
 

Victor Bravo

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At Sockmonkey's airplane rendering emporium we have what you want!
Thanks!

This one here ^^^^^ is the winner out of all the renderings IMHO.

If you put the fuel and battery in the wing, and keep the landing gear very light, you'll have an acceptable compromise in vertical CG, power pitch-over, etc. etc. for reasonably safe flying characteristics.

All the mass and engine up there means that in most types of a serious crash, the heavy parts will pass over the pilot, not through him/her. A good compression-designed strongback serving as the seat upright will push the heavy parts upward over the pilot even more.

The exhaust can be above the center section, keeping noise and fumes out of the cockpit.

The low squatty gear will make it easy to get in and out of, for people with physical ability challenges (pronounced "geezer").

The large side area and rudder will give you plenty of power to recover from any sort of spin issue (at least when the airplane is upright). It won't be an acro airplane anyway.

The thick plank layout will allow you to have a pretty tall spar, and the short span will mean lower bending loads on it... so you have a good shot at a fairly light airplane.

The only downside is that this configuration is not the highest L/D, which means that you will need a little more thrust. Not Saturn rocket thrust, but probably more than 20-25 HP to get a usable airplane.

But I think that is a worthwhile compromise because you get back a lot of structural efficiency, cost, and time.... and a smaller storage space. It looks like the whole mess could slide sideways into a sea container with no disassembly.

Since you're having fun with this and it seems to not be a huge bother to you... how's about one more iteration? Widen the fuselage out to 24 inches (same size/shape door opening) and put the seat and the rudder pedals between the fuselage sides. This creates better structural efficiency in the seat back and windshield uprights, eliminating the need for wing struts and strengthening the wing/fuselage attachment against "roll axis" bending. It also permits Lexan doors to be put into place in the large openings on the sides, hinged at the top, for flying on cooler days.
 
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Sockmonkey

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Since you're having fun with this and it seems to not be a huge bother to you... how's about one more iteration? Widen the fuselage out to 24 inches (same size/shape door opening) and put the seat and the rudder pedals between the fuselage sides. This creates better structural efficiency in the seat back and windshield uprights, eliminating the need for wing struts and strengthening the wing/fuselage attachment against "roll axis" bending. It also permits Lexan doors to be put into place in the large openings on the sides, hinged at the top, for flying on cooler days.
No problem. Me personal favorite is the second one down with the engine in the nose.
Hadn't gotten around to putting gear on that one.
All these are ones I've had on my computer for a while and posted here and there on this site.
As luck would have it, I have your request in stock, I just hadn't put it in the gallery yet.
 

Victor Bravo

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That's pretty cool !

OK, here are a couple of more things to consider, only if you are enjoying this exercise:

1) Move the rear spar of the wing forward from .75C to .66C, to increase the chord of the control surfaces.
2) Move the ailerons outboard and reduce aileron span slightly, to allow for a separate elevator (1/3 span) in the middle. (This simplifies the control system, gets rid of an elevon mixer)
3) Remove the portion of the rudder sticking up above the trailing edge.
4) Increase the root chord of the elevator at the center, tapering it to meet the root ends of the ailerons at their chordwise location. (This is for pitch damping)
5) Adjust the arch of the main gear strut/rod such that the pilot's seat is 18-20 inches above the ground. (This unfortunately may mean the nosewheel needs a short strut tube.)
 

Sockmonkey

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That's pretty cool !

OK, here are a couple of more things to consider, only if you are enjoying this exercise:

1) Move the rear spar of the wing forward from .75C to .66C, to increase the chord of the control surfaces.
2) Move the ailerons outboard and reduce aileron span slightly, to allow for a separate elevator (1/3 span) in the middle. (This simplifies the control system, gets rid of an elevon mixer)
3) Remove the portion of the rudder sticking up above the trailing edge.
4) Increase the root chord of the elevator at the center, tapering it to meet the root ends of the ailerons at their chordwise location. (This is for pitch damping)
5) Adjust the arch of the main gear strut/rod such that the pilot's seat is 18-20 inches above the ground. (This unfortunately may mean the nosewheel needs a short strut tube.)

Isn't 1/3 chord to much for ailerons?
Anyhow, done properly, elevons have simpler control runs than separate aileron/elevator setups.
A mixer isn't needed if you do it the way the Horten wing did.
With a span this short you can get away with just an elevator if you want to go really simple
Moving the rudder down is no problem as the taller gear gives it landing clearance.
Is the extra pitch damping needed? The center chord extension adds some complexity to the build, and if you're going to do different rib sizes, you may as well do it like the second green one above.
 

Aesquire

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Rochester, NY, USA
I like!

how about optional wing extensions for the motor glider guys?

That's for the rectangular wing.
I gather a different shape is better for the low AR designs? The design above with an AR of 7-8 might be a better choice, if storage is not the driving requirement. Or removable outer wing panels?
 

Aesquire

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Rochester, NY, USA
Re: Inflatable

As a buddy often reminds me, "everything you know is wrong". Uses it when we plan a new computer build, "The whole storage system is this stick of gum sized card?" " No, that was last year, you need the one the size of your little fingernail"...

Ditto other things, when I don't pay attention.

The current crop of kite boarding & wingfoil inflatables is using impressive tech and getting good results.

The old school rubber covered fabric of the inflatables of my youth is passe. Even though the Goodyear panel system for their plane is incredible.

Vinyl? Hah! Dacron & new ultralight fabrics and polyurethane tubes. I'd check out the tech before designing! You might not care for the Rogallo and crescent kite shapes as wing design, but the construction is nifty.

& Since I recently visited kite sites, I'm getting ads for "stick on inflation valves" obviously for repairs.
 

erkki67

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Romont / Fribourg / Switzerland
I feeling that the rudder should appear above the wing as well, as the prop stream acts up there too.

the tricycle is fine for me as long as the wheels are big, for those not so nice landings.
 

cluttonfred

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Fort Walton Beach, Florida, USA

Isn't 1/3 chord to much for ailerons?
Anyhow, done properly, elevons have simpler control runs than separate aileron/elevator setups.
Al Backstrom planned (but I don't think he ever flew) a plank flying wing with elevons that extended beyond the trailing edge of the wing to get more area and authority and therefore reduce the span of the wing washed out when you pull back on the stick. Might be a good idea here....
 

erkki67

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Widen the fuselage out to 24 inches (same size/shape door opening) and put the seat and the rudder pedals between the fuselage sides. This creates better structural efficiency in the seat back and windshield uprights said:
this is as a sit on top a real motorcycle of the third dimension not a sedan. For the cooler days, use a heated over roll.
 

ElectricFlyer

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Sure thing. I did several different configurations anyhow. Trike, taildragger, wing mounted engine, nose mounted engine, junkers flaps with endplates, folding wing design, etc etc. Also in orange with an elliptical wing and balloon tires because why not? Also in green with swept and unswept tapered wings. We have a blue trike with delta with endplates and junkers flaps, and we got a straight wing with those too. We have your sexy Little Bird clone in war paint in both straight edge and curvy versions.
At Sockmonkey's airplane rendering emporium we have what you want!
No pushers???:eek:
 
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