This is such an exciting project Marty. I'm looking forward to seeing the build progress and the flight report should be fascinating... I've never been able to properly figure how these pure wings are stable in yaw without any form of fin... but I've seen RC models of the Ho 229 fly, so whatever the reason... it works (at least on larger RC models)
 
What wing section does the model use?

Dan:
 
Thanks, I'm not sure if I'll have a flyable model but the build is already presenting new challenges.  
 
How does FAC feel about clear fin(s) if needed?

It looks like an almost flat bottom section with only very slight TE reflex. I'm assuming that there must me quite considerable wing twist.

Steve:
 
This x-section carries thoughout. The wing has twist but not what I would call considerable. The instructions for the full-size model advises to set the elevons 1/16" up for starting rig and to pay extreme attention to getting the C/G spot on. That and experience with these tailless models tells me to make them adjustable.  
 
Dan:
 
Thanks for checking. Regardless the FAC ruling I'm building this model for the challenge but it would be nice to fly it in class.  
 

 
Well I have half the aircraft completed in structural form. Lots of carving and almost no straight lines. Definitely not a beginner project but possible with detail CAD work and laser cutting.  
 
Assembly shown weighs just 5.4gms. While I use 1/16, 1/20 and 1/32 thickness wood attention  to weight could bring  this down by .5gm.  Structure is very rigid and a side profile shows it follows the angles of the original.  
 
I’ve carved additional upturn in the elevon and my tail(?) extension of the center body has pronounced upsweep. Structure is still resting on centerbody assembly risers.

Northrop was also into Flying Wings in a big way, and their prototypes looked promising.  They were somewhat unstable in Yaw so not a good 'bombing platform'.
 
They crashed in mysterious circumstances.  Anyone for a Jetex version?
 
RR

Wow, Marty, you really hit a hot button with me on a couple of things. Here's some more info.  
 
My late uncle is the famous (or infamous) Kenneth Arnold and when I was a kid he drew me a picture of his sitings. Imagine the Ho 229 with curved leading edges and trailing edges complete with the tapered center body and you have his sketch. When he was on the ground later he was describing to a reporter the strange movements that the objects exhibited while flying. He described them as having a twitchy or skipping movement unlike any flying machine of the time. He said the movements were much like a saucer that you would skip across the water, bouncing from one edge to the other. The reporter shortened that down to "flying saucer". I remember my uncle saying how the movement of the machines would be very uncomfortable for a flight crew and his theory was they were not machines but some kind of living space animals or robots (this was long before RPVs!). He never changed his story in any detail for the rest of his life.
 
Fast forward to a few years ago and I had the privilege to hear a talk by retired Gen Bob Cardenas, who was famous for dropping Chuck Yeager but was also a heavy iron test pilot and flew the XB-35 and 49. He devoted a goodly section of his talk to the Northrop wings and found them a fascinating flying machine but very unpleasant from a pilot's standpoint. The stalls were frightening (this is from a test pilot) and the aircraft wanted to tumble about an axis from wing tip to wing tip. In level flight, when the rudder pedal was stomped on and then the feet placed on the floor, the wing would yaw back and forth, never damping out and never increasing and never stopping. It was neutrally stable in yaw. In looking at the heavy bombers all pilots were used to at that time and where they formed their basis of what a "good" aircraft was ( B-17, B-29, B-32) the Northrop wings were as alien as men from mars.
 
Finally, I had a friend who worked on the steath bomber and, according to the talk that circulated around Northrup, when the elder Jack Northrup was finally shown a model of the then-secret bomber he was delighted that his theories were finally proven true. He refused to acknowledge that the shape was detirmined almost exactly by a diagram of radar reflectivity and not by aerodynamics.  
 
I don't think flying wings will ever lose their appeal. I built a glider of the YB-49 and it was one of the coolest models I ever flew.
 
Oops, I think I got a little off topic.

'and, of course, the  German made jet  and rocket powerplants of 1944-45 were the best to be had.'
 
I think there may be a few engineers from Power Jets, Rolls Royce and Metrovick that dispute that claim, but that's as may be.
 
There are also the interesting General Aircraft flying wings from that period, that were undoubtedly an attempt to learn more about some of the work that had been done by the likes of B&V and Horten.  They were by all accounts terrifying to fly and not a little dangerous.  An interesting subject for flying models nonetheless.  Some were gliders, can't remember if there were any powered ones?

What an awesome and menacing shadow that thing will cast from the sky.  Very cool looking Marty.  And very light.

steve,
After you pulled off the X craft i dont think there is a challege to big for you.

Steve:
 
No, the project is as I left it on the posting. I just returned from a long trip to Houston, TX, celebrating my son's wedding and Christmas.  
 
I'm back now and will probably begin final detailing and covering soon.    
 
Weather permitting I'll be cat lanching it in a week or two.

 
More progress to report on the Ho229V3 FLYING WING.  
 
Covering is completed. The bottom covering was no big deal but as I laid the top sheet on the framework it became apparent the top covering was going to be very difficult. In the end I covered it full wet, starting mid span and working toward each end. The outboard panel was no biggie but moving toward the center was a real challenge. There are no wrinkles but this required a lot of stretching as the center body spread out and humped up.  
 
Basic airframe weight as shown  is 16.4 gms. at 20 “ wingspan.  The overhead shot shows a new finding  for me. This 5.7gm. lump of clay is needed to obtain the correct balance with a spent L2 casing. Total weight as I take it to cat launch will be 22.1gms. Final model with canopy, engine nacelles, finish color and trough liner will approach 27 gms, motor mount empty. The second shot shows the bare trough which has moderate impinging.  
 
WINGs may have light airframe construction but the configuration requires consolidating  all your heavy components in a relativity small area. In the case of the single Rapier powered model this is difficult so it will carry what I consider excessive dead weight.
 
Assuming I accomplish a flying model this configuration is better suited to twin EDF units with associated twin LiPo batteries and controller in the extreme nose . This power system hardware will consolidate productive weight where it's needed most for an efficient model.    
 
 

Oh, a failed to mention. If you look at the shot of the bottom there is balsa filling on either side of the trough. This filling allows addition of one or two clear fins if directional instability is found during cat launch trimming.  
 
We have snow on the ground right now so I'm not sure when that will happen.  
 
Now, what to build...........

Thanks for contacting me. Sorry I can't help you with plans. My model was inspired by plans for a 54" wingspan twin ducted fan R/C model. The owner of the plans is very protective of his design and I promised him I would not make copies of any size.  
 
I gave this model away to a local guy who followed this build and wanted to pursue it further. I was evaluating this configuration for low wing loading. It comes out the excessive weight added to the nose to bring the C/G in negates the potential benefits. For an R/C or FF ducted fan model the electronics and batteries can be packaged to provide this necessary ballast and the configuration becomes more acceptable