Flying Wing : Scratch Design

I've always loved the flying wings and tailless airplanes. I however don't think they end up being very practical. The prone position should be reconsidered. I don't believe you can lay in that position for any length of time and be confortable. Out of all the examples you list the DavisWing appeals to me the most.

Darrell

 

 

A flying wing that exists and has some models flying is the Mitchell Wing.  I think most of the ones that are flying are using a trike with flight controls, rather than a hang glider type control frame like most trikes use.  I think the last owner of the design may have folded up, as the website for Ameriplanes doesn't come up, and the latest date I found of any conversation from the owner of Ameriplanes was in 2003. I didn't get very deep into my search about the Mitchell wing, so you might be able to glean some more information about it.  The Yahoo Group might be a good place to start.

Somewhere around 20 years ago, the Mitchell wing was being built in Kansas, maybe Hayes, and they were doing aircraft, kits, and plans, if I remember correctly.  It is an aluminum skin aircraft, but I'm not sure if the spars and ribs were aluminum or not.  I would think you would have better luck aerodynamically flying suspended below the wing, like a hang glider pilot, rather than laying on top of the airfoil, if you are wanting to fly in a prone position.  I have friends who are pretty deep into the competition end of hang gliding, who regularly fly 5 or 6 hours in a meet.  Another option would be to enclose a cockpit built into the upper surface of the wing, and sit in a supine position.  My interest in the Mitchell wing 20 years ago, was the hang glider version, rather than the powered version.  There is a Yahoo group for the Mitchell wing.  The Mitchell Wing Yahoo Group is here:  http://groups.yahoo.com/group/mitchellwing/

Not quite sure why you want to use the flying wing here. Or, at least, the types you've referred to so far. And I'm not sure it's right to talk about  "the flying wing concept". There is a sort of flying wing that comes to mind, and that's the V-173 aka flying flapjack, prototype for a fighter. Although it's kind of overweight for your mission, it's one of the few aircraft which, according to reports, had the kind of takeoff and landing rolls you're talking about, and a top speed considerably greater than you require. However, the drawback is that you'd have to find a reliable way to drive those two props out at the edges of the aircraft. They're critical to this concept. Since you don't have to fly inverted, you may be able to get by with a better shape and less power. I'm thinking a long drive belt which drove both props might be good. You don't want one of the props to keep going if the other one isn't working.

I think you might find Zimmerman's patent for the V-173 interesting. Also, Zimmerman's two reports on "airfoils" (really wings) which can be found on ntrs.nasa.gov.   (try a search on his name, and the dates which are in the 1930's). Lots of other neat stuff at ntrs.

A delta wing might be something to consider, particularly since there's more documentation on them than the other low aspect ratio types, and more than for other flying wings too.

A tricky issue with a low aspect ratio aircraft like this is that the cheapo design software won't handle it correctly. I'm not sure what the solution for that is, particularly if you can't build anything. (Like a scale flying model, perhaps.) But I think it's one way to approach your "mission".

I'm not sure being on the outside of an aircraft going 90 mph would be very much fun. And it will cost lots of performance.

If your requirement for a flying wing was relaxed, you might be able to do this with a cleaned up, somewhat overpowered, conventional ultralight design. A lot easier to design one of those.

Your mission spec makes me think of the Colditz glider! You don't happen to be stuck someplace, do you? ;-p

 

BTW, some other downloadable tools you might find useful would be XFLR, Xfoil, Profili and Xplane (Xplane and the more useful version of Profili are not free, the others are). But as I mentioned, they may not be very accurate for a low aspect ratio aircraft.

 

Darrel Whiteaker - Personally I've always loved the blended wing body and plain wing flying wings best. I think it's the simplicity (and subtle complexity) of the design that draws me. I have been thinking about the "prone" position and am beginning to agree with you. I have not-so-fond memories of lying in the snow during training...

Apparently I cannot edit my first post. Here are the specifications I was attempting to edit:

Cruising Speed: 50 - 75mph [was 65 - 90mph]

Endurance: 100 - 200 miles [was 215 - 270 miles]

Payload (minus pilot and fuel): 50lbs

Take-off roll: 100 - 200 feet

Landing roll: 100 - 200 feet

And some tools I found today while working the math out.

http://web2.0calc.com/ - Scientific calculator capable of all low level calculations.

[thanks to Lincoln Ross for these]

http://xflr5.sourceforge.net/xflr5.htm

http://web.mit.edu/drela/Public/web/xfoil/

http://www.profili2.com/

http://www.x-plane.com/

Regards and thank you for your time,

-Albert Latham

 

Two suggestions:

You might want to look at Fauvel-type flying wings as an alternative to the swept-wing types:

• http://www.nurflugel.com/Nurflugel/Fauvel/e_index.htm
• http://www.marskeaircraft.com (Jim used to sell a nice little monograph on the history of his early flying wing designs, worth asking him if he still has any.)
• http://www.continuo.com/marske/index.htm
• http://www.foxpapa.com/spip.php?article910 (scroll down, it's in French, but great pics, use Google Translate if needed)

Expensive, but a useful resource is:

Tailless Aircraft in Theory and Practice by Karl Nickel

Cheers,

Matthew

Hi Albert,

You can buy plans for the Mitchell Wing B-10 and U-2 here...

 

http://home.earthlink.net/~mitchellwing/index.html

 

Unfortunately, the last person associated with the design of the Mitchell Wings, Richard Avalon, died last year. His wife is selling the plans.

 

Probably won't finish for a few years since I'm in no real hurry, but I'm currently building a U-2. It looks like it'll meet most of your specs, except the prone and outside part, but I suppose you could do that if you want.

 Hi, Albert,

A friend is building a Fauvel AV-222 motor glider. It is a two-seater, side-by-side, and you sit inside. He first built a model to prove the concept. The model failed miserably because the airfoil was wrong. But then he was able to get a computer program that allowed him to plot the correct airfoil full-size (dot-matrix printer), and from that he reduced the scale and built a second model with the correct airfoil. That second model was simply marvelous in flight. There was essentially no difference in performance or flight characteristics from normal models. I don't have any parameters for the airplane's performance, but best recollection is that they were very similar to yours. Good luck.

.......Ray

If you are looking for library copies of flying wing plans as a learning tool, the San Diego Air & Space Museum archives include the Mitchell B-10 and U-2 plans and they will send you large-size photocopies for a modest fee.  See "Drawings" at http://www.aerospacemuseum.org/library/collections.html.  Cheers, Matthew

Matthew Long - Wow! I spent the first half of today reading through those links! That was fantastic! Thank you. As for the book you mention, I'm going to have to look pretty hard for it as Amazon doesn't have it in right now. Both Marske and Fauvel are extremely inspiring, and useful references.

Andy Gamache - That U-2 is quite something. I may spend the money so I can analyze the plans at a later date. Do you have pictures of your current build? That would be something I would love to see.

Ray Ordorica - I looked up the AV-222 which led me to the Nurflugel sight here: http://www.nurflugel.com/Nurflugel/Fauvel/e_AV222.htm

Well, airfoil is everything here because there are no tailing airfoils to balance the moments, or at least make them tolerable.

Matthew Long - To be honest, I would feel much more comfortable purchasing the plans from the widower of the last man related to the craft... Though, thank you for the link! I'm thinking I might be able to get plans from some of the other long abandoned wings.

As for progress made...

The math available from Chris Heintz I find to be somewhat lacking when it comes to useful specifications. Though I guess any foundation to start from is better than none. I'm going to have to come at this from another direction; I managed to find the specifications for the Wee Bee (mentioned in my first post). They are as follows:

--Specifications--

Wing Span: 18 ft

Wing Chord: 2 ft 5 in

Wing Area: 44 sq ft

Length: 14 ft 2 in

--Performance--

Empty Weight: 210lbs

Max Weight at Take Off: 410lbs (pilot and fuel)

Max Speed: 82 mph

Cruising Speed: 75mph

Range: 50 miles

Service Ceiling: 10,000 feet

The performance numbers for the Wee Bee fit the "mission profile" I want my aircraft to fill. One thing will be changed however (for a price payed in performance) is the range of the craft. I would like something with at least short legs on it so I was thinking somewhere in the neighborhood of 150 miles would be a reasonable distance to expect from a small flying wing coupled with the other performance specifications.

Regards, and thank you for your time,

-Albert Latham

Hi Albert,

I suggest that you download the "demo" version of the X-Plane simulator. In addition to x-plane.exe, you get airfoil-maker.exe and plane-maker.exe. You can use the last two to design your flyng wing and test fly it with x-plane.exe ... all without spending a cent! The only problem is that your joystick will stop working after a few minutes if you don't spend the $30 to buy the CDs.

Contact me at chuckbodeen@earthlink.net if you have any problems with the X-Plane package.

Chuck Bodeen, Panama City Beach, FL

look at this body of work\

http://www.continuo.com/marske/

 

http://www.marskeaircraft.com/

 

 

 

Chuck Bodeen - Last I checked the X-Plane simulator could not realistically handle low aspect ratio or flying wing type aircraft. Also, because of my location downloading anything that large is out of the question due to my internet speed. I am on the equivalent of a 56k line. Maybe a little faster.

I also don't have a joystick. I'm pretty much unable to do any kind of flight testing simply because of my location and access/limits to materials and equipment.

Regards, and thank you for your time,

-Albert Latham

Jim Heffelfinger - Those links were already posted farther up the thread by Matthew Long. Thank you, though, for bringing those links to my attention again.

I have participated in building a high performance flying wing glider, the SB-13 (Akaflieg Braunschweig) and also flew it. You can find pictures on the Akaflieg's website. There are many disadvantages to the flying wing concept and too few advantages. I have discussed this in my book "Homebuilt Aerodynamics and Flight Testing" (http:www.caro-engineering.com), based on my own experience. While the SB-13's performance was very good, it had some handling issues. They are the reason why, after several years of being flown in the group, the SB-13 now is retired and in a museum.

 

Sonja

I'm with Sonja.  While lifting bodies and flying wings are great ideas, they're very unforgiving if you get them wrong in stability.  The B2 for example will not work very well if the computers are off line.  A lot of testing and mdeling should be done to determine the flight characteristics.  If you get it wrong these designs can bite.

Unfortunately, there isn't much to show. I have a few ribs built, but I'm redoing all of them since I don't like the way they turned out. Here's a link to me building my first rib if you're interested. BTW... I work REAL fast in that video!!

 

There's a Yahoo! group called U-2Wing that you can join. There a bunch of pictures there. http://groups.yahoo.com/group/U-2Wing/

 

With luck, I should have all my trailing ribs done by the end of June.

 

Later!!

 

Andy

Hi, Albert.

      First of all, thank you very much for your service and best of luck to you. I built and flew a Mitchell Wing B-10 (wooden wing) back in the '80's. At the time, it represented, to me anyway, the ultimate in looks, performance and "ease of construction" while remaining legal in the ultralight category. My 241 lb B-10 was overpowered with a 28 hp Rotax 277. The factory recommended the 20 hp Zenoah. I loved the way it flew, but it definitely required that the pilot learn different techniques to successfully fly it. Not difficult, just different if you are used to flying a Cessna. The design required that the pusher engine be mounted with a high thrust line so that in a stall, application of engine power would lower the nose assisting recovery. Having such a huge engine caused large pitch changes with any power adjustments. This is a characteristic common to pusher aircraft, even those that have a tail. Having a tractor engine would minimize even eliminate this problem. There have been some tractor engined low aspect ratio flying wings that might fit your design criteria- notably the ARUP from the '30's. Other similar designs include the Hoffman "Batwing" and Milt Hatfield's "Little Bird" series. There is an excellent article by Bernard Rice available as a reprint from issue 24 of Contact! magazine about these and other aircraft.

That Fauvel av-222 looks much like the Alpaero Choucas:

http://alpaero.free.fr/choucas/english/index.htm

In fact they reference the av-221 and the Fauvel site http://www.survol.cjb.net/.

Maybe you can glean some information from those spots, I'm reviewing the English version of the Fauvel site even now.